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FIELD OF THE INVENTION
This invention relates to a process for the graft copolymerization of propylene polymer materials.
BACKGROUND OF THE INVENTION
The morphology of particles of grafted polyolefins is dependent on the polymerization conditions and on the porosity of the material used as the backbone of the graft copolymer. When the porosity of the starting material is too low, a typical polypropylene graft copolymer with 85 parts of monomer added per hundred parts of polypropylene has a tendency to form a surface layer with a high polymerized monomer content ("shelling"). When the monomer add level is high, this shelling often produces a tacky surface on the particles, resulting in poor flowability of the polymer particles, which in turn may cause reactor fouling.
A variety of polymerization inhibitors have been used during graft polymerization reactions. For example, U.S. Pat. No. 3,839,172 discloses a process for the radiation grafting of acrylic monomers onto perhalogenated olefin polymer substrates in which a polymerization inhibitor such as ferrous ammonium sulfate or copper chloride is present in the grafting medium to prevent homopolymerization of the acrylic monomer. U.S. Pat. No. 4,196,095 discloses the use of a polymerization inhibitor such as a combination of copper and copper acetate in a process for the radiation grafting of a hydrophilic compound onto a hydrophobic substrate in the presence of a crosslinking agent and a polar solvent-soluble substance. U.S. Pat. No. 4,377,010 discloses the use of homopolymerization inhibitors such as ferrous sulfate or potassium ferricyanide during the radiation-initiated graft polymerization of acrylic monomers onto a base polymer to make a biocompatible surgical device. U.S. Pat. No. 5,283,287 discloses the use of polymerization inhibitors such as catechol, hydroquinones, organic sulfides, and dithiocarbamates to control the sequence of acrylonitirile units in a process for preparing thermoplastic resin compositions having excellent HCFC resistance.
However, there is still a need for polymerization rate modifiers that will inhibit surface polymerization during the graft polymerization of propylene polymer materials and therefore improve the processability of the resulting polymer particles.
SUMMARY OF THE INVENTION
The process of this invention for making a graft copolymer comprises, in a substantially nonoxidizing environment,
(a) treating particles of a propylene polymer material with an organic compound that is a free radical polymerization initiator;
(b) treating the propylene polymer material over a period of time that coincides with or follows (a), with or without overlap, with about 5 to about 240 parts of at least one grafting monomer capable of being polymerized by free radicals, per hundred parts of the propylene polymer material, in the presence of a polymerization rate modifier capable of functioning in a substantially nonoxidizing environment; and
(c) removing any unreacted grafting monomer from the resulting grafted propylene polymer material, decomposing any unreacted initiator, and deactivating any residual free radicals in the material.
Use of the polymerization rate modifier increases the polymerization induction time on the surface and consequently facilitates diffusion of the monomer into the particles of the propylene polymer material used as the starting material. Surface polymerization is inhibited and therefore the resulting particles exhibit a lower polymerized monomer content on the surface of the particles than in the interior of the particles. The polymerization rate modifier has no significant impact on the number average and weight average molecular weight, molecular weight distribution, xylene solubles at room temperature, grafting efficiency, or the mechanical properties of the graft copolymer product.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a Fourier transform infrared (FTIR) scan along the radius of a microtomed particle of a graft copolymer comprising a backbone of polypropylene, to which was grafted polystyrene. In (A), no sulfur was added to the monomer feed as a polymerization rate modifier (PRM). In (B), 200 parts of sulfur per million parts by weight of styrene were added. In (C), 400 ppm sulfur were added.
FIG. 2 is a FTIR scan along the radius of a microtomed particle of a graft copolymer comprising a backbone of polypropylene, to which was grafted polystyrene. In (A), no sulfur was added to the monomer feed as a PRM. In (B), 400 ppm of sulfur were added.
FIG. 3 is a FTIR scan along the radius of a microtomed particle of a graft copolymer comprising a backbone of polypropylene, to which was grafted polystyrene. Three plots are shown: without the addition of a PRM, with the addition of 50 parts of 1,4-benzoquinone per million parts of styrene, and with the addition of 800 ppm 1,4-benzoquinone.
FIG. 4 is a FTIR scan along the radius of a microtomed particle of a graft copolymer comprising a backbone of polypropylene, to which was grafted poly(methyl methacrylate-co-methyl acrylate). Two plots are shown: without the addition of a PRM and with the addition of 1350 parts of 1,4-benzoquinone per million parts by weight of monomer.
FIG. 5 is a FTIR scan along the radius of a microtomed particle of a graft copolymer comprising a backbone of polypropylene, to which was grafted polystyrene. Two plots are shown: without the addition of a PRM and with the addition of 750 parts of N,N-diethylhydroxylamine per million parts by mole of styrene.
DETAILED DESCRIPTION OF THE INVENTION
The propylene polymer material that is used as the backbone of the graft copolymer can be:
(a) a crystalline homopolymer of propylene having an isotactic index greater than 80, preferably about 85 to about 99;
(b) a crystalline random copolymer of propylene and an olefin selected from the group consisting of ethylene and C 4 -C 10 α-olefins, provided that when the olefin is ethylene, the maximum polymerized ethylene content is 10% by weight, preferably about 4%, and when the olefin is a C 4 -C 10 α-olefin, the maximum polymerized content thereof is 20% by weight, preferably about 16%, the copolymer having an isotactic index greater than 85;
(c) a crystalline random terpolymer of propylene and two olefins selected from the group consisting of ethylene and C 4 -C 8 α-olefins, provided that the maximum polyinerized C 4 -C 8 α-olefin content is 20% by weight, preferably about 16%, and, when ethylene is one of the olefins, the maximum polyinerized ethylene content is 5% by weight, preferably about 4%, the terpolyiner having an isotactic index greater than 85;
(d) an olefin polymer composition comprising:
(i) about 10 parts to about 60 parts by weight, preferably about 15 parts to about 55 parts, of a crystalline propylene homopolymer having an isotactic index greater than 80, preferably about 85 to about 98, or a crystalline copolymer selected from the group consisting of (a) propylene and ethylene, (b) propylene, ethylene and a C 4 -C 8 α-olefin, and (c) propylene and a C 4 -C 8 α-olefin, the copolymer having a propylene content of more than 85% by weight, preferably about 90% to about 99%, and an isotactic index greater than 85;
(ii) about 3 parts to about 25 parts by weight, preferably about 5 parts to about 20 parts, of a copolymer of ethylene and propylene or a C 4 -C 8 α-olefin that is insoluble in xylene at ambient temperature; and
(iii) about 30 parts to about 70 parts by weight, preferably about 20 parts to about 65 parts, of an elastomeric copolymer selected from the group consisting of (a) ethylene and propylene, (b) ethylene, propylene, and a C 4 -C 8 α-olefin, and (c) ethylene and a C 4 -C 8 α-olefin, the copolymer optionally containing about 0.5% to about 10% by weight of a diene, and containing less than 70% by weight, preferably about 10% to about 60%, most preferably about 12% to about 55%, of ethylene and being soluble in xylene at ambient temperature and having an intrinsic viscosity of about 1.5 to about 4.0 dl/g;
the total of (ii) and (iii), based on the total olefin polymer composition being from about 50% to about 90%, and the weight ratio of (ii)/(iii) being less than 0.4, preferably 0.1 to 0.3, wherein the composition is prepared by polymerization in at least two stages and has a flexural modulus of less than 150 MPa; and
(e) a thermoplastic olefin comprising:
(i) about 10% to about 60%, preferably about 20% to about 50%, of a propylene homopolymer having an isotactic index greater than 80, or a crystalline copolymer selected from the group consisting of (a) ethylene and propylene, (b) ethylene, propylene and a C 4 -C 8 α-olefin, and (c) ethylene and a C 4 -C 8 α-olefin, the copolymer having a propylene content greater than 85% and an isotactic index of greater than 85;
(ii) about 20% to about 60%, preferably about 30% to about 50%, of an amorphous copolymer selected from the group consisting of (a) ethylene and propylene, (b) ethylene, propylene, and a C 4 -C 8 α-olefin, and (c) ethylene and a C 4 -C 8 α-olefin, the copolymer optionally containing about 0.5% to about 10% of a diene, and containing less than 70% ethylene and being soluble in xylene at ambient temperature; and
(iii) about 3% to about 40%, preferably about 10% to about 20%, of a copolymer of ethylene and propylene or a C 4 -C 8 α-olefin that is insoluble in xylene at ambient temperature,
wherein the composition has a flexural modulus of greater than 150 but less than 1200 MPa, preferably about 200 to about 1100 MPa, most preferably about 200 to about 1000 MPa.
Room or ambient temperature is ˜25° C.
The C 4-8 α-olefins useful in the preparation of (d) and (e) include, for example, butene-1; pentene-1; hexene-1; 4-methyl-1-pentene, and octene-1.
The diene, when present, is typically a butadiene; 1,4-hexadiene; 1,5-hexadiene, or ethylidenenorbornene.
Propylene homopolymer is the preferred propylene polymer material.
The preparation of propylene polymer material (d) is described in more detail in U.S. Pat. Nos. 5,212,246 and 5,409,992, the preparation of which is incorporated herein by reference. The preparation of propylene polymer material (e) is described in more detail in U.S. Pat. Nos. 5,302,454 and 5,409,992, the preparation of which is incorporated herein by reference.
The process of this invention is most effective when the particles of propylene polymer material have a particle size greater than 150 μm. When the particle size is less than 150 μm, diffusion of the polymerizable monomer into the particle is usually rapid enough without using a polymerization rate modifier (PRM).
The monomers that can be graft polymerized onto the propylene polymer material backbone can be any monomeric vinyl compound capable of being polymerized by free radicals wherein the vinyl radical, H 2 C═CR--, in which R is H or methyl, is attached to a straight or branched aliphatic chain or to a substituted or unsubstituted aromatic, heterocyclic, or alicyclic ring in a mono- or polycyclic compound. Typical substituent groups can be alkyl, hydroxyalkyl, aryl, and halo. Usually the vinyl monomer will be a member of one of the following classes: (1) vinyl-substituted aromatic, heterocyclic, or alicyclic compounds, including styrene, vinylnaphthalene, vinylpyridine, vinylpyrrolidone, vinylcarbazole, and homologs thereof, e.g., alpha- and para-methylstyrene, methylchlorostyrene, p-tert-butylstyrene, methylvinylpyridine, and ethylvinylpyridine; (2) vinyl esters of aromatic and saturated aliphatic carboxylic acids, including vinyl formate, vinyl acetate, vinyl chloroacetate, vinyl cyanoacetate, vinyl propionate, and vinyl benzoate; and (3) unsaturated aliphatic nitriles and carboxylic acids and their derivatives, including acrylonitrile, methacrylonitrile, acrylarnide, methacrylamide; acrylic acid and acrylate esters, such as the methyl, ethyl, hydroxyethyl, 2-ethylhexyl, and butyl acrylate esters; methacrylic acid, ethacrylic acid, and methacrylate esters, such as the methyl, ethyl, butyl, benzyl, phenylethyl, phenoxyethyl, epoxypropyl, and hydroxypropyl methacrylate esters; maleic anhydride, and N-phenyl maleimide. Free radical-polymerizable dienes, such as butadiene, isoprene and their derivatives, can also be used. Multiple monomers from the same or different classes can be employed. Styrene, methyl methacrylate, methyl acrylate, inethacrylic acid, maleic anhydride, and acrylonitrile are the preferred grafting monomers.
The monomers are added in an amount of from about 5 parts to about 240 parts per hundred parts of the propylene polymer material, preferably about 20 to about 100 pph.
The graft copolymer is made by forming active grafting sites on the propylene polymer material by treatment with a peroxide or other chemical compound that is a free radical polymerization initiator. The free radicals produced on the polymer as a result of the chemical treatment initiate the polymerization of the monomers at these sites.
During the graft polymerization, the monomers also polymerize to form a certain amount of free or ungrafted polymer or copolymer. The morphology of the graft copolymer is such that the propylene polymer material is the continuous or matrix phase, and the polymerized monomers, both grafted and ungrafted, are a dispersed phase.
The treatment of the polymer with the initiator and with the grafting monomer is carried out in a substantially nonoxidizing atmosphere, as are the subsequent steps of the process. The expression "substantially nonoxidizing", when used to describe the environment or atmosphere to which the propylene polymer material is exposed, means an environment in which the active oxygen concentration, i.e., the concentration of oxygen in a form that will react with the free radicals in the polymer material, is less than 15%. Concentrations of less than 5% are preferred, and more preferably less than 1% by volume. The most preferred concentration of active oxygen is 0.004% or lower by volume. Within these limits, the nonoxidizing atmosphere can be any gas, or mixture of gases, that is oxidatively inert toward the free radicals in the olefin polymer material, e.g., inert gases such as nitrogen, argon, helium, and carbon dioxide.
Preparation of graft copolymers by contacting a propylene polymer material with a free radical polymerization initiator such as an organic peroxide and a vinyl monomer is described in more detail in U.S. Pat. No. 5,140,074, the preparation of which is incorporated herein by reference.
In the process of this invention the treatment of the propylene polymer material with the vinyl monomer is carried out in the presence of a PRM. The monomer and PRM are fed continuously into the reactor during the course of the polymerization. The PRM can be any free radical polymerization inhibitor that can function in a substantially nonoxidizing environment. Suitable PRMs include, for example, elemental sulfur; picric acid; benzoquinone and its derivatives; hydroxylamine and its derivatives; p-nitroso-N,N-dimethylaniline; N, N-nitrosomethylaniline; dinitrobenzenes; 1,3,5-trinitrobenzene; ferric chloride, and 1,3,5-trinitrotoluene. Sulfur, benzoquinone compounds, and hydroxylamine compounds are preferred.
Suitable benzoquinone compounds include, for example, 1,4-benzoquinone; 2-chloro-1,4-benzoquinone; 2,5-dimethyl-1,4-benzoquinone; 2,6-dichlorobenzoquinone; 2,5-dichlorobenzoquinone; 2,3-dimethyl-1,4-benzoquinone, and di-, tri- and tetrachloro-1,4-benzoquinones.
Suitable hydroxylamine compounds include, for example, N,N-diethylhydroxylamine; N,N-dimethylhydroxylamine; N,N-dipropylhydroxylamine, and N-nitrosophenylhydroxylamine.
The amount of PRM used depends upon the type of compound that is selected, but is generally within the range of about 5 parts to about 5000 parts by mole per million parts of monomer. For example, sulfur is used in an amount of about 50 to about 2000 parts per million parts of the polymerizable monomer, preferably about 100 parts to about 1000 parts. A benzoquinone compound or a hydroxylamine compound is used in an amount of about 50 parts to about 3000 parts per million parts of the polymerizable monomer, preferably about 100 parts to about 1500 parts.
As shown in FIGS. 1-5, the polymer particles without a PRM form a surface layer rich in polymerized monomer, since the polymerization rate is faster than the diffusion rate of the monomer into the polymer particles. When a PRM is added to the monomer feed, the surface of the particles contains monomer whose polymerization is retarded by the presence of the PRM. The monomer, along with the PRM, diffuses into the polymer particles. As the monomer diffuses into the polymer particle, it has no contact with fresh monomer feed containing the PRM, and therefore begins to polymerize. A radial distribution of the PRM occurs due to the reaction between the PRM and the free radicals. The polymerization starts where the PRM concentration is not high enough to stop the polymerization. This produces a low polymerized monomer content in the surface layer. Polymer particles with a low surface content of polymerized monomer have a less tacky surface during polymerization and thus better processability. No significant changes in the number average and weight average molecular weight, molecular weight distribution, xylene solubles at room temperature, grafting efficiency, or % conversion of monomer to polymer were found when a PRM was present during the graft polymerization.
It was also found that the use of N,N-diethylhydroxylamine as the PRM provided the additional benefit of suppressing gas phase polymerization and therefore reducing reactor fouling. The higher the reaction temperature, the greater the reduction in reactor fouling, since the effective concentration of the PRM in the vapor phase increases with the reaction temperature. N,N-diethylhydroxylamine is effective in reducing reactor fouling because of its low boiling point (125°-130° C.) compared to other PRMs and therefore a higher concentration in the gas phase under the reaction conditions.
Although the use of a PRM in a graft polymerization reaction has been described in terms of grafting polymerizable monomers onto solid particles of the backbone polymer, a PRM can also be used during a suspension or emulsion graft polymerization process or in reactive extrusion, processes which are well known to those skilled in the art.
The porosity of the propylene homopolymer used as the backbone polymer in the manufacture of the graft copolymers in the examples is measured as described in Winslow, N. M. and Shapiro, J. J., "An Instrument for the Measurement of Pore-Size Distribution by Mercury Penetration," ASTM Bull., TP 49, 39-44 (February 1959), and Rootare, H. M., "A Review of Mercury Porosimetry," 225-252 (In Hirshhom, J. S. and Roll, K. H., Eds., Advanced Experimental Techniques in Powder Metallurgy, Plenum Press, New York, 1970).
The % xylene solubles at 25° C. was determined by dissolving 2 g of polymer in 200 ml of xylene at 135° C., cooling in a constant temperature bath to 25° C. and filtering through fast filter paper. An aliquot of the filtrate was evaporated to dryness, the residue weighed, and the weight % soluble fraction calculated.
The test methods used to evaluate the molded specimens were:
______________________________________Izod impact ASTM D-256ATensile strength ASTM D-638-89Flexural modulus ASTM D-790-86Flexural strength ASTM D-790-86Elongation at break ASTM D-638-89Melt flow rate, 230° C., 3.8 kg ASTM 1238Weldline strength ASTM D-638-89______________________________________
In this specification, all parts and percentages are by weight unless otherwise noted.
EXAMPLE 1
This example demonstrates the effect of using sulfur as a PRM during a graft polymerization reaction using a propylene homopolymer (PP) as the polymer backbone, to which was grafted polystyrene (PS).
The propylene homopolymer used as the backbone polymer was spherical in form, had a MFR of 15.5 g/10 min and a porosity of 0.17 cm 3 /g, and is commercially available from Montell USA Inc.
The monomers were grafted onto the polypropylene backbone at a grafting temperature of 120° C. using the previously described peroxide-initiated graft polymerization process. Eighty-five parts by weight of styrene were added per 100 parts of polypropylene. Lupersol PMS 50% t-butyl peroxy-2-ethyl hexanoate in mineral spirits, commercially available from Elf Atochem, was used as the peroxide initiator. The monomer was fed at 1 pph/min. A monomer to initiator molar ratio of 105 was used. The reaction conditions were maintained at 120° C. for 30 minutes after monomer addition was completed and the temperature was then raised to 140° C. for 60 minutes under a nitrogen purge. The polymerization reactor was a two gallon autoclave equipped with a helical blade agitator and a monomer feed pump, as well as a temperature control system.
The graft copolymer is characterized in Table 1. In Table 1, the sulfur content is given as parts per million parts by weight of styrene, the feed rate is given as parts of styrene monomer per hundred parts of propylene homopolymer/min. Total polystyrene was determined with a BioRad FSS-7 Fourier transform infrared (FTIR) analyser and is expressed as parts of polystyrene per hundred parts of polypropylene. The molecular weight measurements were made by gel permeation chromatography.
TABLE 1______________________________________Sample Control 1 2______________________________________Sulfur (ppm) 0 200 400Feed rate (pph/min) 1 1 1Total PS (pph) 77.8 91.6 88.9Mn (× 10.sup.-3) 74 68 72Mw (× 10.sup.-3) 291 267 315Mw/Mn 3.9 3.9 4.4Free PS (wt. %) 32.5 35.0 33.1Graft efficiency 25.7 26.8 29.7(wt. %)Agitator speed Fell to 0 when 85 120 throughout 120 throughout(rpm) pph monomer were added______________________________________
For the control sample, in which no sulfur was present during graft copolyinerization, there was difficulty with agitation after the addition of about 70 parts of styrene per hundred parts of polypropylene. After all of the monomer was added the agitator stopped completely, which resulted in agglomerates and chunks.
The data show that there is no significant difference in molecular weight, molecular weight distribution, or grafting efficiency between the polymer made with sulfur as the PRM and without sulfur.
FIG. 1 is a plot of the PS/PP ratio along the radius of the polymer particles against the distance from the surface of the polymer particles in microns (A) when no sulfur was added, (B) when 200 parts of sulfur per million parts by weight of styrene were added, and (C) when 400 ppm sulfur were added. The plots were made by Fourier transform infrared (FTIR) mapping. A very pronounced polystyrene surface layer was found in the polymer without sulfur. When 200 ppm sulfur were added during graft polymerization, the surface polystyrene concentration was greatly decreased, and the polystyrene concentration increased in the interior of the particles. The surface polystyrene concentration decreased even further with the addition of 400 ppm sulfur. At this level of addition, the surface layer had less polystyrene than the inside of the polymer particles.
EXAMPLE 2
This example demonstrates the effect of using sulfur as a PRM during a graft polymerization reaction using a propylene homopolymer as the polymer backbone, to which was grafted polystyrene.
The propylene homopolymer used as the backbone polymer was spherical in form, had a MFR of 20 g/10 min and a porosity of 0.36 cm 3 /g, and is commercially available from Montell USA Inc. The graft copolymer was prepared as described in Example 1. The graft copolymer is characterized in Table 2.
TABLE 2______________________________________Sample Control 1 2______________________________________Sulfur (ppm) 0 400 1200Feed rate (pph/min) 1 1 1Total PS (pph) 85.1 85.0 80.3Mn (× 10.sup.-3) 71 71 52Mw (× 10.sup.-3) 263 288 245Mw/Mn 3.7 4.1 4.7Free PS (wt. %) 32.5 34.7 33.0Graft efficiency 29.4 24.5 25.9(wt. %)Agitator speed Fell to 0 when 85 120 throughout 120 throughout(rpm) pph monomer were added______________________________________
The data show that there is no significant difference in molecular weight, molecular weight distribution, or grafting efficiency between the polymer made with sulfur as the PRM and without sulfur.
FIG. 2 is a plot of the PS/PP ratio along the radius of the polymer particles against the distance from the surface of the polymer particles in microns (A) when no sulfur was added, and (B) when 400 parts of sulfur per million parts by weight of styrene were added. The plots were made by FTIR mapping. A pronounced polystyrene surface layer was found in the polymer without sulfur. The surface polystyrene concentration decreased with the addition of 400 ppm sulfur. At this level of addition, the surface layer had less polystyrene than the portion of the polymer particles below the surface.
EXAMPLE 3
This example illustrates the effect of the morphology of the polymer particles, the the monomer content, and the test conditions on the flowability of graft copolymer particles in the presence of various amounts of sulfur as the PRM. The graft copolymer was made from a propylene homopolymer backbone, to which was grafted polystyrene.
The propylene homopolymer used as the backbone polymer was the same as in Example 1. The graft copolymer was prepared as described in Example 1. The polymer particles were subjected to a flowability test as described below. The amount of sulfur present, the temperature of the test, and the maximum styrene concentration for adequate flowability are shown in Table 3.
The flowability test was conducted at two temperatures, i.e., room temperature (22°-25° C.) and 100° C. The samples were placed in a round bottom glass flask that was immersed in an oil bath to control the temperature of the sample. Styrene with 5000 ppm of t-butyl catechol inhibitor to prevent thermal polymerization during testing was added to the polymer at the required dosage and agitated in the flask for 30 minutes before conducting the flowability test. The amounts of monomer added to the samples were 0, 1, 2, 3, 5, 10, and 30 wt. %. ASTM D-1895-89, "Apparent Density, Bulk Factor and Pourability of Plastic Materials" was used to evaluate the flowability of samples prepared under various conditions. The results are given in Table 3.
TABLE 3______________________________________ Maximum StyreneSulfur Temperature Concentration(ppm) (° C.) (wt. %) Comments______________________________________ 0 Room <1 Tapped funnel at 0% styrene 0 100 <1200 Room <3200 100 <3 Tapped funnel at 2% styrene400 Room No limit Up to 30% styrene400 100 <30______________________________________
The flowability of the samples corresponded quite well to their morphology. The samples prepared without sulfur had a thick layer of polystyrene at the surface of the particles. Flow through the funnel stopped at a styrene monomer concentration of <1% due to surface stickiness. Samples prepared with 200 ppm sulfur had good flowability until the styrene monomer concentration reached 3 wt. %. The best flowability was obtained from the samples with 400 ppm sulfur addition during polymerization. These samples flowed through the funnel even at a styrene monomer concentration of 10 wt. % at 100° C. and of 30 wt. % at room temperature.
EXAMPLE 4
This example describes the effect of sulfur addition on the mechanical properties of impact-modified formulations containing graft copolymers comprising a propylene homopolymer backbone, to which was grafted polystyrene.
The graft copolymers were made from a propylene homopolymer backbone, to which was grafted 85 parts of polystyrene per hundred parts of polypropylene as described in Example 1. The propylene homopolymer used as the polymer backbone for graft copolymer 1 had a MFR of 9 g/10 min, a porosity of 0.51 cm 3 /g and a bulk density of 0.36 g/cm 3 , and is commercially available from Montell USA Inc. The propylene homopolymer copolymer 2 had a porosity of 0.17 cm 3 /g. The propylene homopolymer used as the backbone polymer for graft copolymer 3 had a porosity of 0.36 cm 3 /g.
The graft copolymers were blended with 34.9% by weight of a broad molecular weight distribution polypropylene (BMWD PP) having a polydispersity index of 7.4, a MFR of 1 g/10 min, and xylene solubles at room temperature of 1.5%, commercially available from Montell USA Inc.
The samples were compounded on a 34 mm co-rotating, intermeshing Leistritz LSM twin screw extruder. Each sample was extruded as pellets at a barrel temperature of 230° C., a screw speed of 375 rpm, and a throughput rate of 36 lb/hr for the Control Sample and Sample 1, and 43 lb/hr for Sample 2.
The stabilizer package used was 0.1% of calcium stearate and 0.2% of Irganox B-225 antioxidant, a blend of 1 part Irganox 1010 tetrakis methylene(3,5-di-tert-butyl-4-hydroxyhydrocinnamate)!methane stabilizer and 1 part Irgafos 168 tris(2,4-di-tert-butylphenyl) phosphite stabilizer, commercially available from CIBA Specialty Chemicals Corporation.
In Table 4 the impact modifiers were Kraton RP6912 styrene/ethylene-isoprene/styrene tri-block copolymer, commercially available from Shell Chemical Company, and EPM 306P random ethylene/propylene copolymer having an ethylene content of 57%, commercially available from the Polysar Rubber Division of Miles, Incorporated.
TABLE 4______________________________________Sample Control 1 2______________________________________Sulfur content (ppm) 0 200 400Graft copolymer 1 (wt. %) 34.9Graft copolymer 2 (wt. %) 34.9Graft copolymer 3 (wt. %) 34.9BMWD PP (wt. %) 34.9 34.9 34.9Kraton RP 69l2 (wt. %) 15.0 15.0 15.0EPM 306P (wt. %) 15.0 15.0 15.0Irganox B225 (wt. %) 0.2 0.2 0.2Calcium stearate (wt. %) 0.1 0.1 0.1______________________________________
The compounded samples were dried at 80° C. for at least 4 hours prior to molding to remove moisture. One inch ×1/8" test bars were used for all of the physical property measurements. Test bars were produced on a 5 oz Battenfeld injection molding machine at a barrel temperature of 450° F. and a mold temperature of 130° F.
The results of the property evaluations for each formulation are given in Table 5. In the table, NB=no break.
TABLE 5______________________________________Sample Control 1 2______________________________________Sulfur content (ppm) 0 200 400MFR (dg/min), 6.4 4.0 4.5(230° C., 3.8 kg)Flexural modulus (kpsi) 108 120 121(1% secant, 0.05"/minFlexural strength (psi) 2903 3231 3273Izod impact strength NB (14.6) NB (14.6) NB (14.3)(ft.lb/in) (@ 23° C.)Izod impact strength 4.2 8.9 4.1(ft.lb/in) (@ -30° C.)Tensile strength (psi) 3258 3475 3269(2"/min)Elongation at break >892 820 709(%)______________________________________
The data show that the physical properties of the samples with sulfur addition during polymerization are similar to those of the control made without sulfur addition.
EXAMPLE 5
This example demonstrates the effect of using 1,4-benzoquinone as a PRM during a graft polymerization reaction using a propylene homopolymer as the polymer backbone, to which was grafted polystyrene.
The propylene homopolymer used as the backbone polymer had a porosity of 0.17 cm 3 /g. The graft copolymer was prepared as described in Example 1.
Without benzoquinone, the conversion of monomer to polymer was 91.7%. With the addition of 50 parts by weight of benzoquinone per million parts of styrene, the conversion was 87.1%. With the addition of 800 ppm benzoquinone, the conversion was 96.2%.
Without the addition of a benzoquinone PRM, the agitator speed fell to 0 when 85 parts of styrene per hundred parts of polypropylene were added. With the addition of 50 ppm of benzoquinone, the agitation decreased to 80 rpm. With the addition of 800 ppm of benzoquinone, the agitator speed remained at 120 rpm throughout the reaction.
FIG. 3 is a plot of the PS/PP ratio along the radius of the polymer particles against the distance from the surface of the polymer particles in microns when no benzoquinone was added, when 50 parts of benzoquinone per million parts by weight of styrene were added and when 800 ppm benzoquinone were added. The plots were made by FTIR mapping. A very pronounced polystyrene surface layer was found on the polymer particles without benzoquinone. When 50 ppm benzoquinone were added during graft polymerization, the surface polystyrene concentration was greatly decreased, and the polystyrene concentration increased in the interior of the particles. The surface polystyrene concentration decreased even further with the addition of 800 ppm benzoquinone. At this level of addition, the surface layer had less polystyrene than the inside of the polymer particles.
EXAMPLE 6
This example shows the effect on polymer properties when 1,4-benzoquinone is used as the PRM during a graft polymerization reaction using two different propylene homopolymers as the backbone polymer, to which was grafted polystyrene.
The graft copolymers were prepared as described in Example 1. The propylene homopolymer used as the backbone polymer for graft copolymer 4 had a porosity of 0.11 cm 3 /g and a bulk density of 0.48 g/cm 3 , and is commercially available from Montell USA Inc. The propylene homopolymer used as the backbone polymer for graft copolymer 1 had a porosity of 0.51 cm 3 /g. The graft copolyiners are characterized in Table 6.
TABLE 6______________________________________GraftCo- Inhibitor Mw Mn PS (pph) XSRT Gr. Eff.polymer (ppm, wt.) (× 10.sup.-3) (× 10.sup.-3) by FTIR (wt. %) (wt. %)______________________________________4 1350 219 51 73.4 29.0 31.64 0 246 67 81.5 36.3 19.31 0 216 61 81.9 33.2 26.41 1350 245 59 76.9 33.5 23.0______________________________________
The data show that there is no significant difference in molecular weight, xylene solubles at room temperature (XSRT), and grafting efficiency between the polymer made with benzoquinone and without benzoquinone, except for a slightly lower grafting efficiency for graft copolymer 4 without a PRM due to "shelling" during polymerization, i.e., a high polymerized monomer content in the surface layer.
EXAMPLE 7
This example describes the effect of the addition of 1,4-benzoquinone on the mechanical properties of impact-modified formulations containing graft copolymers comprising a propylene homopolymer backbone, to which was grafted polystyrene.
The graft copolymers were made from a propylene homopolymer backbone, to which was grafted 85 parts of polystyrene per hundred parts of the polypropylene as described in Example 1. The propylene homopolymer used as the polymer backbone for graft copolymer 1 had a porosity of 0.51 cm 3 /g. The propylene homopolymer used as the backbone polymer for graft copolymer 2 had a porosity of 0.17 cm 3 /g. The propylene homopolymer used as the backbone polymer for graft copolymer 3 had a porosity of 0.36 cm 3 /g. The propylene homopolymer used as the backbone polymer for graft copolymer 4 had a porosity of 0.11 cm 3 /g.
The graft copolymers were blended with 34.9% of the broad molecular weight distribution polypropylene described in Example 4. The samples were compounded as described in Example 4, except that the throughput rate for the Control Sample and Samples 2 and 3 was 36 lb/hr, and for Sample 1 it was 40 lb/hr.
The stabilizer package used was 0.1% by weight of calciun stearate and 0.2% by weight of Irganox B-225 antioxidant, commercially available from CIBA Specialty Chemicals Corporation. The impact modifiers in Table 7 are described in Example 4.
TABLE 7______________________________________Sample Control 1 2 3______________________________________1,4-Benzoquinone (ppm, wt.) 0 1350 1350 1350Graft copolymer 1 (wt. %) 34.9Graft copolymer 2 (wt. %) 34.9Graft copolymer 3 (wt. %) 34.9Graft copolymer 4 (wt. %) 34.9BMWD PP (wt. %) 34.9 34.9 34.9 34.9Kraton RP6912 (wt. %) 15.0 15.0 15.0 15.0EPM 306P (wt. %) 15.0 15.0 15.0 15.0Irganox B225 (wt. %) 0.2 0.2 0.2 0.2Calcium stearate (wt. %) 0.1 0.1 0.1 0.1______________________________________
The samples were compounded and test bars were produced as described in Example 4. The results of the property evaluations for each formulation are given in Table 8. In the table, NB=no break.
TABLE 8______________________________________Sample Control 1 2 3______________________________________1,4-Benzoquinone 0 1350 1350 1350(ppm wt.)MFR (dg/min), 6.4 6.6 6.5 5.8(230° C., 3.8 kg)Flexural modulus (kpsi) 108 110 109 109(1% secant, 0.05"/min)Flexural strength (psi) 2903 2991 2982 2963Izod impact strength NB (14.6) NB (15.1) NB (15.0) NB (15.0)(ft.lb/in) (@ 23° C.)Izod impact strength 4.2 5.7 5.7 8.2(ft.lb/in) (@ -30° C.)Tensile strength (psi) 3258 3174 3299 3367(2"/min)Elongation at break (%) >892 808 873 892______________________________________
The data show that the physical properties of the samples with benzoquinone addition during polymerization have similar physical properties compared to the control made without benzoquinone addition.
EXAMPLE 8
This example illustrates the effect on polymer characteristics and on the physical properties of the polymer when 1,4-benzoquinone is used as a PRM during a graft polymerization reaction using two different propylene homopolymers as the polymer backbone, to which was grafted poly(methyl methacrylate-co-methyl acrylate) (PMMA).
The graft copolymer was prepared as described in Example 1, except that 95 parts of monomer were added per hundred parts of polypropylene, the reaction temperature was 115° C., the monomer to initiator ratio was 120, and the molar ratio of methyl methacrylate to methyl acrylate was 95 to 5. The propylene homopolymer used as the backbone polymer for graft copolymer 1 had a porosity of 0.51 cm 3 /g. The propylene homopolymer used as the backbone polymer for graft copolymer 4 had a porosity of 0.11 cm 3 /g. The graft copolymers are characterized in Table 9.
TABLE 9______________________________________Graft PMMACo- Inhibitor Mw Mn (pph) XSRT Gr. Eff.polymer (ppm, wt.) (× 10.sup.-3) (× 10.sup.-3) by FTIR (wt. %) (wt. %)______________________________________4 0 280 73 50.8 42.3 --4 1350 149 60 88.0 38.6 17.61 0 109 49 88.0 41.7 11.01 800 120 56 83.4 37.2 18.31 1350 132 60 81.4 38.1 15.1______________________________________
The data show that there is no significant difference in molecular weight, xylene solubles at room temperature, and grafting efficiency between the polymer made with benzoquinone as the PRM and without benzoquinone, except for graft copolymer 4 without the PRM. The molecular weight is abnormally high due to severe "shelling" that occurred during polymerization.
The samples were compounded on a 34 mm co-rotating, intermeshing Leistritz LSM twin screw extruder at a barrel temperature of 210° C., a screw speed of 250 rpm, and a throughput rate of 20 lb/hr. Test bars for physical property measurements were prepared as described in Example 4. The results of the property evaluations for each sample are given in Table 10.
TABLE 10______________________________________ Control Control ControlSample 1 2 1 2 3 3______________________________________Graft copolymer 1 1 1 1 4 41,4-Benzoquinone 0 0 800 1350 0 1350(ppm, wt.)Notched Izod at 0.85 0.95 0.84 0.89 0.34 1.0023° C. (ft.lb/in)Notched Izod at 0.18 0.17 0.17 0.19 -- 0.180° C. (ft.lb/in)Tensile strength 5834 5820 5681 5768 5052 5671(psi)Weldline strength 5098 4347 5223 5378 4762 4462(psi)Elongation at break 20 20 16 19 12 19(%)Flexural modulus 338 339 328 327 309 317(0.5"/min) (kpsi)Flexural strength 10150 10220 9980 10000 9020 9860(0.5"/min) (psi)MFR (dg/min) 9.3 11.0 12.0 11.0 -- 9.5(3.8 kg, 230° C.)______________________________________
The data show that the physical properties of the samples with benzoquinone added during polymerization have similar physical properties compared to the control made without benzoquinone addition, except for Control 3 for the reasons given in the previous example.
FIG. 4 is a plot of the PMMA/PP ratio along the radius of the polymer particles (graft copolymer 4) against the distance from the surface of the polymer particles in microns when no benzoquinone was added, and when 1350 parts of benzoquinone were added per million parts by weight of monomer. The plots were made by FTIR mapping. A very pronounced PMMA surface layer was found in the polymer particles without benzoquinone. When 1350 ppm benzoquinone were added during graft polymerization, the surface PMMA concentration was greatly decreased.
EXAMPLE 9
This example demonstrates the effect of using picric acid as a 90% slurry in water as a PRM during a graft polymerization reaction using a propylene homopolymer as the polymer backbone, to which was grafted polystyrene.
The propylene homopolymer used as the backbone polymer had a porosity of 0.17 cm 3 /g. The graft copolymer was prepared as described in Example 1.
Without picric acid, the conversion of monomer to polymer was 91.7%. With the addition of 400 parts by weight of picric acid per million parts of styrene, the conversion was 95.8%. Without the addition of a PRM, the agitator speed fell to 0 when 85 parts of monomer per hundred parts of polypropylene were added. With the addition of 400 ppm of picric acid, the agitator speed remained at 120 rpm throughout the reaction.
EXAMPLE 10
This example demonstrates the effect of using N,N-diethylhydroxylamine (DEHA) as a PRM during a graft polymerization reaction using a propylene homopolymer as the polymer backbone, to which was grafted polystyrene.
The propylene homopolymer used as the backbone polymer had a porosity of 0.17 cm 3 /g. The graft copolymer was prepared as described in Example 1. The graft copolymer is characterized in Table 11.
TABLE 11______________________________________DEHA Mw Mn PS (pph) XSRT Gr. Eff.(ppm, mole) (× 10.sup.-3) (× 10.sup.-3) by FTIR (wt. %) (wt. %)______________________________________ 0 291 74 77.8 32.5 25.7 830 213 60 78.0 34.2 22.01660 204 60 80.3 34.8 21.9______________________________________
The data show that there is no significant difference in molecular weight, total polystyrene, xylene solubles at room temperature, or grafting efficiency between the polymer with DEHA as the PRM and without DEHA.
Without DEHA, the % conversion of monomer to polymer was 91.7. With the addition of 830 parts of DEHA per million parts of styrene (by mole), the conversion was 97.7%, and with 1660 ppm DEHA (by mole) the conversion was 98.2%.
Without the addition of a PRM, the agitator speed fell to 0 when 85 parts of styrene were added per hundred parts of polypropylene. With the addition of 830 and 1660 ppm DEHA, the agitator speed remained at 120 rpm throughout the reaction.
EXAMPLE 11
This example describes the effect of the addition of DEHA as a PRM on the polymer properties during a graft polymerization reaction using a propylene homopolymer as the polymer backbone, to which was grafted poly(methyl methacrylate-co-methyl acrylate).
The propylene homopolymer used as the backbone polymer had a porosity of 0.11 cm 3 /g. The graft copolymer was prepared as described in Example 1, except that 95 parts of monomer were added per hundred parts of polypropylene, the monomer to initiator molar ratio was 120, the reaction temperature was 115° C., and the ratio of methyl methacrylate to methyl acrylate was 95 to 5. The graft copolymer is characterized in Table 12.
TABLE 12______________________________________DEHA Mw Mn XSRT Gr. Eff.(ppm, mole) (× 10.sup.-3) (× 10.sup.-3) (wt. %) (wt. %)______________________________________1000 127 49 36.3 16.31500 135 45 37.0 10.01750 143 48 36.6 15.4______________________________________
The data show that there is no significant difference in molecular weight, xylene solubles at room temperature, and grafting efficiency between the polymer made with various amounts of DEHA as the PRM.
With the addition of 1000 parts of DEHA per million parts of methyl methacrylate (by mole), the conversion of monomer to polymer was 91.2 weight %. With the addition of 1500 ppm DEHA (by mole), the conversion was 92.5%. With the addition of 1750 ppm DEHA (by mole), the conversion was 88.0%.
When a PRM was present, the agitator speed remained at 120 rpm throughout the reaction.
EXAMPLE 12
This example illustrates the effect of the morphology of the polymer particles on the % conversion of monomer to polymer and the flowability of the polymer particles. The graft copolymer was made from two different propylene homopolymers as the polymer backbone, to which was grafted polystyrene. The PRM was DEHA.
The graft copolymers were prepared as described in Example 1, except that the polymerization reactor is a 130 liter Littleford reactor which has a horizontal mechanical agitator and is commercially available from Littleford Day, Inc. The propylene homopolymer used as the polymer backbone for graft copolymer 1 had a porosity of 0.51 cm 3 /g. The propylene homopolymer used as the backbone polymer for graft copolymer 4 had a porosity of 0.11 cm 3 /g.
The flowability of the polymer particles was indicated by the maximum current requirement for the agitator in amps. The higher the amperage, the poorer the flowability. The results are given in Table 13.
TABLE 13______________________________________Graft DEHA Conversion Max. Current RequirementCopolymer (ppm, mole) (wt. %) for Agitator (amps)______________________________________1 0 99.6 6.51 1000 97.3 6.44 0 95.6 11.74 750 97.5 8.24 1000 95.3 7.54 1250 98.2 7.2______________________________________
The data show that the flowability improved when DEHA was present during the polymerization.
FIG. 5 is a plot of the PS/PP ratio along the radius of the polymer particles (graft copolymer 4) against the distance from the surface of the polymer particles in microns when no DEHA was added and when 750 parts of DEHA per million parts of styrene (by mole) were added. The plots were made by FTIR mapping. A very pronounced polystyrene surface layer was found on the polymer particles without the addition of DEHA. When 750 ppm DEHA were added during graft polymerization, the surface polystyrene concentration was greatly decreased, and the polystyrene concentration increased in the interior of the particles.
EXAMPLE 13
This example describes the effect on reactor fouling of adding DEHA to the monomer feed as a PRM during a graft polymerization reaction. The graft copolymer was made from a propylene homopolymer as the backbone polymer, to which was grafted polystyrene.
The propylene homopolymer used as the backbone of the graft copolymer had a porosity of 0.51 cm 3 /g. The graft copolymer was prepared as described as in Example 1 except that the reaction temperature was 110° C. for the Control Sample and Samples 1 and 2, and the monomer to peroxide molar ratio was 49.0 at 110° C. Forty-five parts of styrene were added per hundred parts of polypropylene.
In order to quantify the degree of reactor fouling, a "test coupon", an in-line filter basket containing 40 g of the propylene homopolymer, was placed in the gas recirculation stream. The % increase in weight of the test coupon during the reaction was an indication of the extent of reactor fouling. The greater the weight increase, the more reactor fouling occurred.
The amount of DEHA introduced, the % yield calculated from the mass balance, the PS content of the product measured by FTIR, the reaction temperature, and the % increase in coupon weight are given in Table 14.
TABLE 14______________________________________ Product Coupon PS Wt. Yield Content Reaction IncreaseSample PRM (wt. %) (pph) Temp. (° C.) (wt. %)______________________________________Control None 95.2 41.1 110 30.01 DEHA, 1000 97.3 42.1 110 17.0 ppm (mol)2 DEHA, 1000 97.3 38.9 110 23.2 ppm (mol)3 DEHA, 1000 94.7 37.2 120 6.75 ppm (mol)______________________________________
The data show that the use of DEHA in the monomer feed resulted in a reduction in gas loop fouling, especially at the higher reaction temperature.
EXAMPLE 14
This example describes the effect on reactor fouling of adding DEHA to the monomer feed as a PRM during a graft polymerization reaction. The graft copolymer was made from a propylene homopolymer as the backbone polymer, to which was grafted poly(methyl methacrylate-co-methyl acrylate) (PMMA).
The propylene hoinopolymer used as the backbone of the graft copolymer had a porosity of 0.51 cm 3 /g. The graft copolymer was prepared as described in Example 1, except that the reaction temperature was 115° C., the monomer to peroxide molar ratio was 120, the molar ratio of methyl methacrylate to methyl acrylate was 95 to 5, and 45 parts of monomer were added per hundred parts of polypropylene.
The degree of reactor fouling was quantified as described in Example 13. The amount of DEHA introduced, the % yield calculated from the mass balance, the PMMA content of the product measured by FTIR, and the % increase in coupon are given in Table 15.
TABLE 15______________________________________ Product Coupon PMMA Wt. Yield Content IncreaseSample Inhibitor (wt. %) (pph) (wt. %)______________________________________Control None 100.0 33.8 45.51 DEHA 100.0 39.6 22.0 500 ppm (mol)2 DEHA 96.6 39.9 20.0 500 ppm (mol)______________________________________
The data show that the use of DEHA in the monomer feed resulted in a reduction in gas loop fouling.
Other features, advantages and embodiments of the invention disclosed herein will be readily apparent to those exercising ordinary skill after reading the foregoing disclosures. In this regard, while specific embodiments of the invention have been described in considerable detail, variations and modifications of these embodiments can be effected without departing from the spirit and scope of the invention as described and claimed. | A graft copolymer comprising a backbone of a propylene polymer material having a vinyl monomer graft polymerized thereto is produced by (1) treating a propylene polymer material with a free radical polymerization initiator, (2) treating the propylene polymer material with at least one grafting monomer capable of being polymerized by free radicals, in the presence of a polymerization rate modifier, and (3) removing any unreacted grafting monomer from the graft copolymerized propylene polymer material, decomposing any unreacted initiator, and deactivating any residual free radicals in the material. Use of the polymerization rate modifier increases the polymerization induction time on the polymer surface, consequently facilitating monomer diffusion into the interior of the polymer particles so that surface polymerization of the monomer is inhibited. | 2 |
RELATED APPLICATION
The present application claims priority of Italian Patent Application No. MI2005A002051 filed Oct. 27, 2005, which is incorporated herein in its entirety by this reference.
FIELD OF THE INVENTION
The present invention relates to a control device of a switching converter with an overcurrent protection circuit and the related switching converter.
BACKGROUND OF THE INVENTION
Switching converters such as the buck converter shown in FIG. 1 are generally known in the current state of the art. Said converter comprises an MOS transistor 1 having a non-drivable terminal connected to an input voltage Vin and another non-drivable terminal connected to the cathode of an asynchronous rectifier diode D 1 having its anode connected to ground GND; the transistor 1 is driven by a control device 2 . The cathode of the diode D 1 is connected to a low-pass filter comprising an inductor L and a capacitor C from whose ends the converter output voltage Vout is drawn.
In conditions of operation with the continuous conduction mode (CCM). that is when the current in the inductor L never goes to zero, and with a resistive type of load LOAD, if the transistor I has an “on” time Ton and an “off” time Toff, where T=Ton+Toff, it follows that Vout=D*Vin where D is the duty cycle given by D=Ton/T. In conditions of operation with the discontinuous conduction mode (DCM), that is when the current in the coil goes to zero during the switching period, the output voltage Vout is a function of the value of the inductor L, time period T, duty cycle D and input voltage Vin, i.e.,
Vout = 2 Vin 1 + ( 1 + 8 L RT * 1 D 2 ) 2
where R is the resistive value of the load LOAD.
Another buck converter layout is shown in FIG. 2 . The converter comprises a first MOS transistor HS having a non-drivable terminal connected to the input voltage Vin and another non-drivable terminal P connected to a terminal of the inductor L and a non-drivable terminal of a second MOS transistor LS connected to ground GND. The other terminal of the inductor L is connected to the capacitor C, having its other terminal connected to ground GND; the capacitor C is placed in parallel with the load LOAD and a resistive divider comprising a series of two resistors, R 1 and R 2 . A fraction MFB of the output voltage Vout is input to a control device 20 . The transistors HS and LS are switched on in a push-pull mode and as a result there is a lower power dissipation, given that the voltage drop across the transistor LS is lower than the voltage drop on the diode.
The control device 20 comprises a first circuit 24 comprising in turn an error amplifier 26 for comparing the voltage VFB with a reference voltage Vref and means able to effect a pulse width modulation (PWM) in response to said comparison. The control device 20 comprises two drive circuits or drivers 21 and 22 receiving as inputs the PWM signals output by the circuit 24 and able to drive the transistors HS and LS via the signals HSIDE and LSIDE. The driver 22 is powered by a voltage Vccdr whereas driver 21 is powered by a voltage Vcb originating from a bootstrap circuit 23 comprising a capacitor Cboot situated between the node P and the cathode of a diode Dcb having its anode connected to the voltage Vccdr.
When the converter is switched on, the node P is grounded GND and the capacitance Cboot is charged to the voltage Vccdr−Vd where Vd is the voltage drop of the diode Deb. When a pulse arrives from the PWM signal output by the circuit 24 , the driver 21 starts to charge the gate of the transistor HS, supplying a charge Q drawn from the capacitance Cboot. When the transistor HS is switched on, the node P is brought to the voltage Vin and the voltage Vcb is forcibly brought to the voltage Vin+Vcboot where Vcboot is the voltage at the ends of the capacitor Cboot. In this condition the driver 21 supplies a voltage to the gate of the transistor HS that is sufficient to keep it on. The switching cycle concludes with the switching off of the transistor HS, whose gate is brought to the voltage of the node P. When the transistor LS is switched on, the node P is again brought to ground GND and the capacitance Cboot is thus recharged via the diode Dcb.
In order to prevent that in particular malfunction conditions the current carried by the transistors may rise to such a point as to damage or break them, overcurrent protection circuits are included in the regulators. There are a variety of devices able to implement overcurrent protection. Said devices include means capable of sensing the current that flows in the transistor or in the inductor L. Overcurrent protection is usually introduced in order to be able to guarantee a current limit even with switch-on times Ton shorter than the minimum time necessary for obtaining a reliable reading of the current in the transistor HS. Because of the noise due to parasite components and to the switching operations of the transistors, a masking interval (Tmask) is introduced in the current detection. Within this interval of time immediately after switching, no overcurrent is considered. It follows that in the case of switch-on times Ton shorter than Tmask any occurring overcurrent would be ignored, for this reason a reading of the current on the transistor LS is introduced.
When an overcurrent occurs there are various possibilities for intervention to avoid damage to the device or application.
One of said possibilities is to implement a protection device on the constant current, which once the threshold current IL_TH has been fixed, acts upon the circuit 24 in such a way as to maintain on the inductor a constant peak current equal to the value of the predefined threshold current.
The overcurrent protection in the constant current mode is implemented using a reading on the transistor HS or on both transistors, HS and LS. In the latter case, when an overcurrent is detected during the switch-off time Toff, the transistor LS is kept on for as long as said condition persists and the transistor HS is never switched on, as occurs with the device 27 of FIG. 2 . This implies that no switch-on pulses will be considered for the transistor HS in order to guarantee the current limit. In such conditions it is possible to guarantee overcurrent protection between duty cycles of almost nil and duty cycles close to 100%.
Said type of protection may cause a loss of cycles and the converter may in such a case operate at a subharmonic frequency giving rise to a strong output ripple DIripple where
DIripple = Vin - Vout L Tmask .
In the case of large conversion ratios and a low value filter inductor, the converter may operate with a peak current ILpeak in the inductor exceeding the threshold current IL_TH and a lower working frequency, as is shown in FIG. 3 .
In converters equipped with an overcurrent protection device like the ones previously described, at the end of the load transition that triggers said protection, an undesired over-elongation may occur in the output voltage Vout. In fact, during the action of the protection device, the output voltage Vout falls to a value below the regulation value and the error amplifier output saturates high, given that the feedback signal VFB is at a lower value than Vref. On coming out of said condition the converter will function with elevated duty cycles causing potential over-elongations of the output voltage Vout.
SUMMARY OF THE INVENTION
In view of the current state of the art, the object of the present invention is to provide a control device for a switching converter with an overcurrent protection circuit that overcomes the aforesaid drawbacks.
According to the present invention this object is achieved by means of a switching converter control device having an input terminal and output terminal. The converter includes a semi-bridge of a first and second transistor coupled between the input terminal and a reference voltage. The control device includes first means capable of detecting a signal representative of the signal on the converter output terminal and able to compare it with a reference signal and to emit a first signal in response to said comparison. The control device is suitable for driving said first and second transistors based on said first signal, and comprises a protection circuit able to detect the presence of overcurrents in said semi-bridge and capable of acting upon said first and second transistors in response to said detection. The control device comprises second means capable of acting upon said first means in order to level the value of said first signal after the triggering of said protection circuit.
According to the present invention it is possible to construct a control device for a switching converter with an overcurrent protection circuit that does not allow the formation of over-elongations of the converter output voltage and does not allow the converter to work at a subharmonic frequency. The control device, in the case where the converter has an inductor placed between the output terminal and the common terminal of the transistors, does not allow the formation of a high current ripple in the current present in the inductor.
BRIEF DESCRJPTION OF THE DRAWINGS
The characteristics and advantages of the present invention will become apparent from the following detailed description of a practical embodiment thereof, illustrated as a non-restrictive example in the appended drawings, in which:
FIG. 1 is a diagram of a well-known buck converter layout;
FIG. 2 is a diagram of another buck converter according to the known prior art;
FIG. 3 shows time waveforms of signals involved with the triggering of the protection on the transistor LS where the regulation time period Ton is shorter that the time period Tmask;
FIG. 4 is a diagram of a switching converter provided with a control device according to the present invention;
FIG. 5 is a more detailed diagram of a part of the control device of FIG. 4 ;
FIG. 6 shows timing diagrams of signals involved in the device of FIG. 5 ; and
FIG. 7 shows other timing diagrams of signals involved in the converter of FIG. 4 .
DETAILED DESCRIPTION
FIG. 4 shows a control device of a switching converter according, to the invention. The converter comprises a first MOS transistor HS having a non-drivable terminal connected to the input voltage Vin, present at the converter input terminal IN, and another non-drivable terminal P connected to a terminal of the inductor L and a non-drivable terminal of a second MOS transistor LS connected to ground GND, The other terminal of the inductor L is connected to the converter output terminal OUT and to the capacitor C, whose other terminal is connected to ground GND; the capacitor C is placed in parallel with the load LOAD and a resistive divider comprising a series of two resistors, R 1 and R 2 . A fraction VFB of the output voltage Vout is input to a control device 200 . The transistors HS and LS are switched on in a push-pull mode and this results in a lower power dissipation given that the voltage drop at the ends of the LS transistor is lower than the voltage drop on the diode.
The control device 200 comprises a first circuit 240 comprising in turn an error amplifier 260 suitable for comparing between the voltage VFB and a reference voltage Vref and for producing an output signal COMP and means able to effect a pulse width modulation (PWM) in response to said comparison. The control device 200 comprises two drive circuits or drivers 210 and 220 receiving as inputs the signals HS_ON and LS_ON output by the circuit 240 and which are able to drive the transistors HS and LS via the signals HSIDE and LSIDE. The driver 220 is powered by a voltage Vccdr whereas driver 210 is powered by a voltage Vcb originating from a bootstrap circuit 230 comprising a capacitor Cboot situated between the node P and the cathode of a diode Dcb having its anode connected to the voltage Vccdr.
The control device 200 comprises an overcurrent protection device 270 . Said device is able to detect the current on the transistors HS and LS and to act upon the drive circuits 210 and 220 , causing the transistor HS to switch off and the transistor LS to switch on upon the detection of an overcurrent.
The control device 200 comprises means 100 capable of acting upon the error amplifier 260 so as to limit the value of the output voltage COMP; the means 100 can act upon the output voltage COMP or upon the reference voltage Vref. The means 100 acts directly upon the voltage COMP or upon the reference voltage Vref; preferably said means 100 acts upon the output voltage COMP of said error amplifier 260 to limit the value thereof after the action of said protection device 270 .
This serves to avoid the presence of over-elongation of the output voltage Vout after the triggering of the overcurrent protection device 270 .
Moreover, since the voltage COMP is limited, the maximum switch-on time of the transistor HS is no longer limited to the time period Tmask but is regulated accordingly, thus avoiding cycle skips, the presence of subharmonics and an elevated ripple in the current.
Preferably said means 100 comprises a capacitor Cc which is charged or discharged by a fixed amount of charge at every clock strike, i.e. at every clock pulse fixed by an oscillator 280 ; the voltage at the ends of the capacitor Cc is coupled with the voltage COMP in order to change its value according to whether or not an overcurrent is detected.
Preferably said means 100 comprises a counter, in the event that the control device 200 is of a digital type; the value of said counter is increased or decreased at each clock pulse according to whether or not an overcurrent is detected by the device 270 .
When the presence of an overcurrent is detected by the device 270 , the current that flows in the inductor L is limited to IL_TH; this determines a decrease in the value of the output voltage Vout and the voltage feedback loop reacts by increasing the voltage COMP in an attempt to increase the voltage Vout. The means 100 intervenes to limit the value of the voltage COMP.
FIG. 5 shows in greater detail the means 100 in the case of analogue implementation of the control device 200 . The overcurrent information OCP is normally stored in a latch 271 , which may be seen in FIG. 4 ; the signal OC_LATCH output by said latch 271 is the signal OCP prolonged until the end of the switching cycle. The means 100 comprises a capacitor Cc connected to the gate terminal of a MOS transistor M 1 having its drain terminal connected to a supply voltage Valim and its source terminal connected to a current generator I 3 connected to ground GND. The source terminal of the transistor M 1 is connected to a buffer, and more precisely to the base terminal of a bipolar transistor Q 1 having its emitter terminal connected to a current generator I 4 connected in turn with the supply voltage Valim and its collector terminal connected to ground GND. The emitter terminal of the transistor Q 1 is connected to the base terminal of another bipolar transistor Q 2 having its collector terminal coupled to ground GND by means of a current generator I 5 and its emitter terminal connected with the error amplifier 260 . The latter comprises an input stage 261 and an output stage 262 ; in the input stage the non-reverse input terminal is connected to the voltage Vref whereas the reverse input terminal is connected to tile voltage VFB. The output terminal of the input stage is connected to the gate terminal of a MOS transistor M 2 having its source terminal connected to ground GND and its drain terminal connected to the voltage Valim via a current generator I 6 and connected to the emitter terminal of the transistor Q 2 and to the base terminal of a bipolar transistor Q 3 having its collector terminal connected to Valim and its emitter terminal, at which the voltage COMP is present, connected to ground GND via a current generator I 7 . The capacitor Cc is charged and discharged by means of a charging and discharging circuit 101 comprising current generators and switches. More precisely, a first parallel arrangement of two circuit branches connected to the supply voltage Valim, and in which the first branch comprises a current generator I 1 and the second branch comprises a current generator I 2 connected to a switch S 1 is connected via a switch S 2 to a terminal of the capacitor Cc; a second parallel arrangement of two other circuit branches connected to ground GND, and in which the first branch comprises a current generator I 1 and the second branch comprises a current generator I 2 connected to a switch S 1 , is connected via a switch S 2 to a terminal of the capacitor Cc. The current generators I 1 and I 2 generate a current equal to I and 2*I; the switches S 2 are controlled by a signal BIGSTEP whereas the switch S 1 of the first parallel arrangement of circuit branches is controlled by the signal UP and the switch S 1 of the second parallel arrangement of circuit branches is controlled by the signal DOWN. The signals UP, DOWN and BIGSTEP are delivered by a logic circuit 103 belonging to the means 100 and receiving as inputs the signals CK and OC_LATCH.
The circuit of FIG. 5 is such as to assure that the voltage COMP is lower than the voltage given by VCc+Vgs+Vbe where VCc is the voltage at the ends of the capacitor Cc, the voltage Vgs is the voltage between the gate and source of the transistor M 1 and the voltage Vbe is the voltage between the base and emitter of the bipolar transistor.
If the device 270 detects an overcurrent situation, the switch S 2 driven by the signal DOWN is closed to discharge the capacitor Cc by DVCc=I*Cc for the duration of a clock pulse CK originating from the device 280 ; otherwise the switch S 2 driven by the signal UP is closed to charge the capacitor Cc by DVCC for the duration of a clock pulse. The switches S 2 controlled by the signal BIGSTEP are closed upon every entry into or exit from an overcurrent situation detected by the device 270 .
More precisely, the control logic of the circuit 103 is the following: in the period of time T(n) relative to the nth cycle, if an overcurrent situation occurred in the preceding period of time T(n−1) and in the period of time just before that T(n−2), the voltage VCc is decreased by the amount DVCc; again in the period of time T(n), if an overcurrent situation occurred in the preceding period of time T(n−1) but not in the period of time just before that T(n−2), the voltage VCc is decreased by the amount 3*DVCc; again in the period of time T(n), if an overcurrent situation occurred neither in the preceding period of time T(n−1) nor in the period of time just before that T(n−2), the voltage VCc is increased by the amount DVCc; again in the period of time T(n), if an overcurrent situation did not occur in the preceding period of time T(n−1) but occurred in the period of time just before that T(n−2), the voltage VCc is increased by the amount 3*DVCc.
Shown in FIG. 6 are some possible patterns of the signals CK, OCP, OC_LATCH, BIGSTEP and VCc. In the period of time T 1 , given that the signal OCP is not high, the voltage VCc is increased by the amount DVCc for the period of time Tc of the clock pulse CK. In the period of time T 2 , given that the signal OCP is high, as is the signal BIGSTEP, the voltage VCc is decreased by the amount 3*DVCc for the period of time Tc of the clock pulse CK. In the period of time T 3 , given that the signal OCP is high but the signal BTGSTEP is low, the voltage VCc is decreased by the amount DVCC for the period of time Tc of the clock pulse CK. In the period of time T 4 , given that the signal OCP is low whereas the signal BIGSTEP is high, the voltage VCc is increased by the amount 3*DVCc for the period of time Tc of the clock pulse CK. In the period of time T 4 , given that the signal OCP and the signal BIGSTEP are high, the voltage VCc is decreased by the amount 3*DVCc for the period of time Te of the clock pulse CK.
The means 100 of FIG. 5 also comprises a circuit 102 comprising a MOS transistor having its gate terminal controlled by the signal COMP, its drain terminal connected to the voltage Valim and its source terminal connected to ground GND via a current generator I 8 . The source terminal of the transistor M 3 is connected to the gate terminal of the transistor M 4 having its source terminal connected to the gate terminal of the transistor M 1 and its drain terminal connected to ground GND. The circuit 102 allows an auto-leveling of the means 100 . Absent the means 102 , where no overcurrent condition is detected, the voltage VCc would saturate high at the voltage Valim because at every clock pulse CK it is increased by DVCc. The presence of the means 102 guarantees the saturation of the voltage VCc at a level just slightly higher than the voltage COMP; accordingly, when an overcurrent situation is detected the means 100 will be inactive for a few clock cycles, which will be necessary in order for the voltage VCc to fall to the value COMP; with the circuit 102 the voltage VCc is leveled to the voltage COMP.
Shown in FIG. 7 are some possible time trends of the voltages COMP, VCc and VFB in the time periods T 1 p -T 4 p.
In the period of time T 1 p , there are normal operating conditions in which the voltage COMP is regulated by the voltage loop and the voltage VCc is linked to the voltage COMP.
In the period of time T 2 p an overcurrent situation has been detected; the device 270 switches off the transistor HS, switches on the transistor LS and imposes a threshold current IL_TH. The voltage loop reacts by raising the signal COMP; the voltage VCc starts falling but has not yet linked to the signal COMP.
In the period of time T 3 p the voltage signal VCc has linked to the signal COMP and forces it down; the voltage loop opens and the voltage VFB falls.
In the period of time T 4 p , the overcurrent situation having ceased, the transistors HS and LS are governed by the signal COMP, which is fixed by the signal VCc. The output voltage Vout stabilizes at a value such that IL=IL_TH and VFB=Vout.
While there have been described above the principles of the present invention in conjunction with specific memory architectures and methods of operation, it is to be clearly understood that the foregoing description is made only by way of example and not as a limitation to the scope of the invention. Particularly, it is recognized that the teachings of the foregoing disclosure will suggest other modifications to those persons skilled in the relevant art. Such modifications may involve other features which are already known per se and which may be used instead of or in addition to features already described herein. Although claims have been formulated in this application to particular combinations of features, it should be understood that the scope of the disclosure herein also includes any novel feature or any novel combination of features disclosed either explicitly or implicitly or any generalization or modification thereof which would be apparent to persons skilled in the relevant art, whether or not such relates to the same invention as presently claimed in any claim and whether or not it mitigates any or all of the same technical problems as confronted by the present invention. The applicant hereby reserves the right to formulate new claims to such features and/or combinations of such features during the prosecution of the present application or of any further application derived therefrom. | A control device of a switching converter having an input terminal, an output terminal and a semi-bridge of a first and second transistor coupled between the input terminal and a reference voltage, includes a first circuit for detecting a signal representative of the signal on the converter output terminal and able to compare it with a reference signal and to emit a first signal in response to the comparison. The control device drives the first and second transistors based on the first signal and includes a protection circuit to detect the presence of overcurrents in the semi-bridge and acting upon the first and second transistors in response to the detection. The control device includes a second circuit for acting upon the first circuit in order to level the value of the first signal after the triggering of the protection circuit. | 7 |
PRIORITY INFORMATION
This application claims the benefit of U.S. Provisional Application No. 60/390,634 on Jun. 21, 2002.
FIELD OF THE INVENTION
The field of this invention relates to techniques and equipment to gravel-pack and treat closely spaced zones and more particularly in applications where some degree of isolation is desired between the zones for accommodating different treatment plans.
BACKGROUND OF THE INVENTION
In producing hydrocarbons or the like from loose or unconsolidated and/or fractured formations, it is not uncommon to produce large volumes of particulate material along with the formation fluids. As is well known in the art, these particulates routinely cause a variety of problems and must be controlled in order for production to be economical. A popular technique used for controlling the production of particulates (e.g., sand) from a well is one which is commonly known as “gravel-packing.”
In a typical gravel-packed completion, a screen is lowered into the wellbore on a work string and is positioned adjacent to the subterranean formation to be completed, e.g., a production formation. Particulate material, collectively referred to as “gravel,” and a carrier fluid is then pumped as a slurry down the work string where it exits through a “cross-over” into the well annulus formed between the screen and the well casing or open hole, as the case may be. The carrier liquid in the slurry normally flows into the formation through casing perforations, which, in turn, is sized to prevent flow of gravel therethrough. This results in the gravel being deposited or “screened out” in the well annulus where it collects to form a gravel pack around the screen. The gravel, in turn, is sized so that it forms a permeable mass, which allows the flow of the produced fluids therethrough and into the screen while blocking the flow of the particulates produced with the production fluids.
One major problem that occurs in gravel-packing single zones, particularly where they are long or inclined, arises from the difficulty in distributing the gravel over the entire completion interval, i.e., completely packing the entire length of the well annulus around the screen. This poor distribution of gravel (i.e., incomplete packing of the interval) is often caused by the carrier fluid in the gravel slurry being lost into the more permeable portions of the formation, which, in turn, causes the gravel to form “sand bridges” in the annulus before all the gravel has been placed. Such bridges block further flow of slurry through the annulus, which prevents the placement of sufficient gravel (a) below the bridge in top-to-bottom packing operations or (b) above the bridge in bottom-to-top packing operations.
To address this specific problem, “alternate path” well strings have been developed which provide for distribution of gravel throughout the entire completion interval, even if sand bridges form before all the gravel has been placed. Some examples of such screens include U.S. Pat. Nos.: 4,945,991; 5,082,052; 5,113,935; 5,417,284; 5,419,394; 5,476,143; 5,341,880; and 5,515,915. In these well screens, the alternate paths (e.g., perforated shunts or bypass conduits) extend along the length of the screen and are in fluid communication with the gravel slurry as the slurry enters the well annulus around the screen. If a sand bridge forms in the annulus, the slurry is still free to flow through the conduits and out into the annulus through the perforations in the conduits to complete the filling of the annulus above and/or below the sand bridge.
One of the problems with the alternate path design is the relatively small size of the passages through them. These tubes are also subject to being crimped or otherwise damaged during the installation of the screen. Thus, several designs in the past have placed these tubes inside the outer surface of the screen. This type of design substantially increases the cost of the screen over commercially available screens. Yet other designs have recognized that it is more economical to place such tubes on the outsides of the screen and have attempted to put yet another shroud over the alternate paths which are on the outside of the screen to prevent them from being damaged during insertion or removal. Such a design is revealed in U.K application No. GB 2317 630 A.
While such designs can be of some benefit in a bridging situation, they present difficulties in attempting to treat and gravel-pack zones which are fairly close together. Many times zones are so close together that traditional isolation devices between the zones cannot be practically employed because the spacing is too short. For example, situations occur where an upper and lower zone are spaced only 5-20 feet from each other, thus precluding a complete completion assembly in between screens for each of the zones. When these closely spaced zones are encountered, it is desirable to be able to gravel-pack and treat the formations at the same time so as to save rig time by eliminating numerous trips into the well. This method was explained in U.S. Pat. No. 6,230,803. At times these types of completions will also require some degree of isolation between them, while at the same time producing one or the other of the formations. In U.S. Pat. No. 6,230,803 a method was disclosed to facilitate fluid treatments such as fracture stimulation, as well as gravel packing, simultaneously, in two or more adjacent producing zones, while providing limited hydraulic isolation between two or more adjacent zones. That method minimized rig time for the completion by reducing the number of trips required to install the gravel screen assemblies and to treat the formation. The limitation of that method was that the two zones had to be treated simultaneously. This caused problems if the nature of the adjacent formations necessitated a different treatment program. The isolation of the zones after completion was also less than ideal. Accordingly, the present method seeks to allow the treatment of adjacent zones in a single trip one at a time so that different regimens can be used. It provides, in the preferred embodiment, a check valve for retention of fluids in the string against loss into the formation. It provides an option of isolating a zone while treating the other. The method of the present invention can also be used in a single producing zone to minimize bridging problems during gravel distribution by splitting the zone into segments and gravel packing each segment individually. These objectives and how they are accomplished will become clearer to those skilled in the art from a review of the detailed description of the preferred embodiment and the claims, which appear below.
SUMMARY OF THE INVENTION
A method is disclosed that allows for sequential treatment of two zones in a single trip while isolating the zones. A fluid loss valve prevents the column of fluid in the tubing from flowing into the lower formation until activated. Zone isolation is accomplished by manipulation of a port on a wash pipe attached to the crossover assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a section view of the equipment in place and the upper zone being treated while the lower zone is isolated;
FIG. 2 is the view of FIG. 1 with the lower zone being treated;
FIG. 3 shows both zones treated;
FIG. 4 is an enlargement of the fluid loss prevention valve in the assembly;
FIG. 5 is a detailed view of the wash pipe in position to allow treatment of the upper zone; and
FIG. 6 is the view of FIG. 5 showing the wash pipe positioned for squeezing the lower zone.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a wellbore 10 and zones 12 and 14 to be treated. The preferred embodiment illustrates the method for two zones but those skilled in the art will appreciate that additional zones can be treated in a single trip with duplication of the equipment shown for doing two zones in one trip, as will be explained below. A tubular string 16 is used to run in a known crossover tool 18 , which is movable with respect to packer 20 after it is set. In FIG. 1 , the packer 20 is shown in the set position and the crossover is set up to circulate to deposit gravel outside of screen 22 and adjacent the perforations 24 of zone 12 . Arrows 26 show the gravel and fluid mixture coming from the surface through the string 16 and going through the packer 20 . The gravel and fluid stream indicated by arrows 26 goes through crossover 18 and through ports 28 in the crossover tool 18 . Sliding sleeve valve 30 is left in the open position during run in so that the ports 32 are open for the gravel and fluid stream 26 to pass into annulus 34 . The stream passes through the screen 22 leaving the gravel in annulus 34 and the fluid to pass through the screen 22 into annular space 36 around the wash pipe 38 . Wash pipe 38 has several openings 40 which are shown in FIG. 1 as above seal 42 . Seal 42 keeps clean fluid from going down around the outside of the wash pipe 38 . Any fluid 26 that gets into the wash pipe 38 through openings 40 is stopped from exiting the lower end of the wash pipe 38 by a ball 44 pushed by the flow against a seat 46 . Return flow 26 passes through passage 48 lifting ball 50 off seat 52 . The return flow passes through passage 54 in crossover 18 and up to the surface via annulus 56 above the set packer 20 . A flapper 58 is held open by wash pipe 38 . When the wash pipe 38 is removed, the flapper 58 closes to prevent the column of fluid from the surface inside the string 16 from flowing into the formation and potentially causing damage.
Packer 60 is supported by screen 22 and it in turn supports screen 62 at perforations 64 . Packer 60 is multi-bore. The first bore 66 communicates to inside screen 62 . The second bore 68 communicates with a standpipe 70 that is capped at cap 72 at its upper end. As shown in FIG. 1 gravel is deposited around the outside of standpipe 70 and standpipe 70 extends above perforations 24 . After the zone 12 is fully treated, including gravel packing and other operations that may be needed like acidizing, pressure on cap 72 can be raised to break it to provide access to zone 14 through bore 68 . Cap 72 can be a rupture disc or any other type of barrier that can be removed in any number of ways among them pressure, chemical reaction or some applied force. As shown in FIG. 2 , the gravel and fluid stream 74 passes through standpipe 70 and bore 68 in packer 60 to lodge in annulus 76 adjacent perforations 64 . Returns pass through screen 62 and into wash pipe 38 to displace ball 44 off of seat 46 . Ports 40 in wash pipe 38 are now below seal 42 . This position of ports 40 effectively isolates zone 12 from returns. The returns 74 pass through passage 48 and return to the surface through annulus 56 in the manner previously described for zone 12 . Thus, although the gravel packing is done from top to bottom, each zone is independent and bridging in zone 12 has no effect on the deposition of gravel in zone 14 .
FIG. 3 shows the crossover 18 and wash pipe 38 removed. The flapper 58 has slammed shut to prevent fluid loss to either zone 12 or 14 . Sliding sleeve 30 has been pushed closed by the removal of the wash pipe 38 .
FIG. 5 shows the isolation of the lower zone 14 when treating the upper zone 12 by virtue of having openings 40 above seal 42 . Seal 42 seals around the outside of wash pipe 38 and ball 44 on seat 46 prevents returns from treating the zone 12 from reaching zone 14 . Additionally, bore 68 is closed at this time by cap 72 on standpipe 70 . FIG. 6 shows how zone 12 is isolated when treating zone 14 . Here the returns lift ball 44 off of seat 46 . Ports 40 are now below seal 42 forcing all returns to bypass zone 12 and rise to the crossover 18 . It should be noted that the cross-over 18 can be configured to close access to surface annulus 56 , in which case the gravel packing or acid treating or any other procedure will be without returns or by bull heading into the formation.
FIG. 4 simply illustrates the flapper 58 held open by the wash pipe 38 . It slams shut as soon as the wash pipe 38 is removed.
Those skilled in the art will appreciate that the zones can be closely spaced and can be treated separately in a single trip. Two or more zones can be sequentially treated in a single trip. The treatment can be by circulation with returns to the surface or elsewhere or without returns with the fluids driven into the formation being treated. When treating two zones, one is isolated when the other is treated. Finally, a fluid loss prevention feature, which is a flapper 58 in the preferred embodiment retains the liquid column in the tubular 16 and prevents its passage into the formation. The fluid prevention feature can be a flapper or ball device or any other valve that hold up the liquid column when the wash pipe 38 is pulled out.
The above description is illustrative of the preferred embodiment and many modifications may be made by those skilled in the art without departing from the invention whose scope is to be determined from the literal and equivalent scope of the claims below: | A method is disclosed that allows for sequential treatment of two zones in a single trip while isolating the zones. A fluid loss valve prevents the column of fluid in the tubing from flowing into the lower formation until activated. Zone isolation is accomplished by manipulation of a port on a wash pipe attached to the crossover assembly. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates to a computer mouse, and more particularly, to a touch-control computer mouse which can rapidly and accurately control the positioning of a cursor on a computer display screen.
Conventionally, the positioning of a cursor on a computer display screen may be controlled by a variety of input devices, such as a computer mouse, joystick, keyboard, trackball and digitizer. Drawbacks of these various input devices are discussed below:
1. Computer mouse: The optical and mechanical mouse, each use a rotary ball to carry an x, y rotary axis and rotary encoder so as to obtain corresponding coordinates. This kind of input device must be operated on a plain surface. Therefore, it is not practical for use in a portable PC, in a transportation vehicle or a narrow space. Further, the computer mouse regularly tends to be contaminated with dust or impurities during contact, causing erroneous action or jamming.
2. Joystick: The joystick utilizes a variable resistance and a universal control lever to control horizontal and vertical displacement to further produce a variable potential signal. For use of a joystick, a game control interface must be equipped. Further, joystick input control is power consuming because the electric contact pole of the universal control lever is constantly in contact with the variable resistance. More particularly, joystick input control is not convenient for signal input on a displacement of a long distance.
3. Keyboard: The keyboard is heavy, large and not convenient for graphic input.
4.Trackball: The trackball is similar to computer mouse. However, the rotary ball of a track ball is disposed upward and is relatively bigger, and must be displaced by one or two fingers so as to allocate the positioning of a cursor. Therefore, the operation of a trackball is more inconvenient and tends to cause muscle problems.
5. Digitizer: The Digitizer is not convenient to operate since it requires a magnetic field exciter and an additional power supply.
SUMMARY OF THE INVENTION
It is therefore the main object of the present invention to provide such a touch-control computer mouse which is easy to operate and convenient for carriage.
Another object of the present invention is to provide such a touch-control computer mouse which includes a laminated touch-control film assembly to convert a finger touch signal to a telecommunication signal for the vertical and horizontal coordinates of a computer monitor.
A yet further object of the present invention is to provide such a touch-control computer mouse which is protected in a dust-protective case and may be detachably attached to a PC or communicating equipment by means of a fastening element for convenient operation in a transportation vehicle or narrow space.
According to the present invention, a touch-control computer mouse is comprised of a laminated touch-control film assembly, an aluminum supporting board, a press button switch set, a signal processing circuit board, and a dust-protective hanging case. Drawing using a finger on x-axis and y-axis resistance planes of the laminated touch-control film assembly results in variable potential value for x, y coordinates. The value of potential variation is calculated through a single-chip microprocessor to indicate relative direction, speed and amount of displacement on x, y coordinates. The signal of the relative direction, speed and amount of displacement is further sent by the single-chip microprocessor through a standard RS-232 output to a computer main unit to rapidly and accurately control the positioning of the cursor on the computer display screen.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic drawing in which a touch-control computer mouse which is constructed according to the present invention is connected to portable PC for cursor control;
FIG. 2 is a fragmentary structural view of the present invention;
FIG. 3A is a side sectional view of the laminated touch-control film assembly of the present invention;
FIG. 3B is an exploded view illustrating the composition of the respective layer of the laminated touch-control film assembly of the present invention;
FIG. 4 is a circuit diagram of the present invention; and
FIG. 5 is a flow chart illustrating the operation of the touch-control signal processing.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a schematic drawing of the present invention, in which a touch-control computer mouse (1) of the present invention is plugged into one of the serial communications ports of a portable personal computer (100) via an electric cable (11), and a fastening means (2) is attached to the housing of the computer at one lateral side onto which the casing (12) of the touch-control computer mouse (1) may hang. Through finger (4) contact on the touch-control space (3), the cursor (101) on the screen of the computer (100) is immediately moved to a desired location. After function mode selection is properly made through a press button control switch set (5), data input can then be made through the keyboard of the computer (100).
FIG. 2 is a perspective fragmentary view of a touch-control computer mouse embodying the present invention. As illustrated, a touch-control computer mouse of the present invention is generally comprised of an upper cover (13) defining therein a touch-control space (3), a casing (12), a laminated touch-control film assembly (21), an aluminum supporting board (22), a plurality of supporting stands (23), a signal processing circuit board (24), a press button control switch set (5) for function selection, and an electric cable (11). The signal processing circuit board (24) is internally mounted on the casing (12) in the front region; the press button control switch set (5) for function selection is fixedly set in the back region, the supporting stands (23) are fixedly set around the side-wall; the aluminum supporting board (22) is fixedly mounted on the supporting stands (23) at the top through adhesive connection; the laminated touch-control film assembly (21) is mounted on the aluminum supporting board (22) at the top with its flexible ribbon line (111) connected to the signal processing circuit board (24); and the upper cover (13) is secured to the casing (12) at the top to cover the said component parts therein with the laminated touch-control film assembly (21) disposed in the touch-control space (3). The casing (12) of the present invention comprises several slots (120) made at one lateral side-wall through which the casing (12) may be hung on the fastening element (2) of a computer (100) (see FIG. 1).
FIG. 3A is a sectional view of the laminated touch-control film assembly of the present invention. The laminated touch-control film assembly is comprised, from the top to the bottom in proper sequence, of a plastic film face panel (21), a plane of silver coating (2113), a mylar film layer (211), silver glue conductors (2112), a y-axis resistance plane (2111), a division layer (212), a x-axis resistance plane (2101), silver glue conductors (2102), a mylar film layer (210), and the aluminum supporting board (22). The plane of silver coating (2113) isolates any static electicity or noise resulting from the touching of the finger at the face panel (21). The silver glue conductors (2112) are to derive a reference potential from the y-axis (vertical axis) resistance plane (2111). The division layer (212) is a hollow rectangular frame, to isolate the x-axis resistance plane (2101) and the y-axis resistance plane (2111) from each other and to let the x-axis resistance plane (2101) and the y-axis resistance plane 2111 be connected only when the laminated touch-control film assembly is touched and pressed by a finger or something else. The x-axis (horizontal) resistance plane is to provide a reference potential through the silver glue conductors (2102). The mylar film layers (211) and (210) are for adherence thereto of the component layers respectively. The aluminum supporting board (22) is to firmly support the flexible, light and soft laminated touch-control film assembly against pressing of a finger.
For a better understanding of the structure of the laminated touch-control film assembly of the present invention, please refer to FIG. 3B. As illustrated, the top layer of a laminated touch-control film assembly of the present invention is a plastic film face panel (21); a plane of silver coating (2113) is made on a mylar film layer (211) with a silver glue conductor (the real line at the left) extending therefrom for grounding and noise eliminating; a y-axis resistance plane (2111) is set below (at the back of) the mylar film layer (211) (as illustrated by the dotted line); a silver glue conductor (2112) (in dotted line) is extending from the y-axis resistance plane (2111) at the back side to derive a reference potential from the y-axis (vertical axis) resistance plane (2111); a x-axis (horizontal axis) resistance plane (2101) is mounted on another mylar film layer (210) at the top with two silver glue conductors (2102) extending therefrom for deriving a reference potential; a division layer (212) is set in the middle between the y-axis resistance plane (2111) and the x-axis resistance plane (2101); and an aluminum supporting board (22) is set at the bottom. The division layer (212) is to isolate the x-, y-axis resistance planes from each other when the laminated touch-control film assembly (21) is not touched. The above structural layers are connected together through a heat pressing process to form into a laminated unitary film assembly (21) with a flexible ribbon line, which is comprised of four reference potential output conductors for the x-axis and y-axis and one conductor from the plane of silver coating (2113) for grounding, extending therefrom for connection to the signal circuit processing circuit board (24).
FIG. 4 is a circuit diagram of the present invention, in which the contact position detector (241) serves as a sensing circuit to detect the touching of a finger at the x-axis and y-axis resistance planes (2101) and (2111) so as to provide the single-chip microprocessor (245) with corresponding signal regarding touching or releasing of finger and to help the single-chip mocroprocessor (245) eliminate bounce and control a high-low speed averager (243). The operation of the contact position detector (241) is outlined hereinafter:
When SW1 is pressed to touch at a position x, x', a VTOP to 0 potential is uniformly distributed over the x plain resistance (2101). Under this condition, the y plain resistance (2111) serves as a contact pole to obtain a potential of the contact point at the x plain resistance (2101) so as to read the potential at x-axis from y or y'. Because there is a linear relation between the location and the potential, the location at x-axis can thus be obtained. On the other hand, when SW1 is pressed to touch at a position in y, y', the x plain resistance (2101) serves as a contact pole so as to obtain the location at the y-axis.
According to the foregoing statement, a floating problem may arise from x, y resistance planes when x, y resistance planes are not in contact with each other, and the MPU single-chip microprocessor (245) may erroneously read the data. In order to solve this floating problem, a push high resistor R2 which has a resistance value higher than the plain resistance is mounted on the contact detector (241) at x, x' or y, y'. Therefore, potential reading can be accurately made when one is using one's finger to draw on the laminated unitary film assembly (21) the x, y plain resistance are forced to contact with each other. Because the read out value at any location is smaller than or equal to VTOP and VS is larger than VTOP, the output from the comparator (2411) becomes "1".
When x, y plain resistance (2101) and (2111) are not in contact with each other, the potential at y of the reading value of the contact pole is VCC and higher than VS, because of the operation of R2 and the output of the comparator (2411) becomes "0". Therefore, it can be determined through the output from the comparator (2411) whether the laminated unitary film assembly is touched.
Referring to the circuit diagram of the present invention as illustrated in FIG. 4, a power-saving type constant voltage and ramp generator (242) is used. Because regular IC requires relatively higher working voltage and consumes relatively more power, it is not practical for use in the present touch-control computer mouse. Therefore, a power-saving type constant voltage and ramp generator (242) must be used. The operation of the power-saving type constant voltage and ramp generator (242) of the present invention is discussed below:
A starting resistance R4 provides a bias current with a Zener diode ZD to produce a voltage VZD. The voltage VZD thus obtained is sent to the base of Q1 and Q3 to produce constant current I1 and I2, in which I1=(VZD-0.6V)/R5, I2 =(VZD-0.6V)/R6 (0.6V is a positive voltage). I1 of the transistor Q1 flows through R3 to produce a voltage of I1 R3. The current through the emitter of Q2 then establishes a voltage VS to the load of the x, y resistance planes (2101) and (2111), of which the load current Ic runs further through the Zener diode ZD to provide a VZD voltage. Because of the nature of semiconductor, when load current I1 becomes constant, VZD becomes constant too, and when VZD becomes constant at both ends of the Zener diode ZD, load current I1 becomes a constant value too. The process is repeated again and again to stabilize the VS voltage. The current I1 for the load (x, y plain resistance) is simultaneously provided for the Zener diode ZD to become fully utilized. Because a relatively higher resistance value is adopted, the characteristics of the circuit of the present invention will not be affected by the starting resistance R4. However, if the starting resistance R4 is not used, the circuit will be unable to start (i.e. Q1, Q2, Q3 become a broken circuit).
Further, I2 (the current through Q3) is for generating a ramp. Because I2 is a constant current, the voltage at the capacitor C1 becomes VC=Q/C=(I.T)/C when the capacitor C1 is charged, and I2 (the current from Q3 toward the capacitor C1) is fully utilized for charging the capacitor C1. In the circuit, the SW2 is to control the discharging of the capacitor C1.
The high-low speed averager (243) is used in the contact position detector (241) to stabilize the contact signal for accurate determination by the single-chip microprocessor (245). Because a human finger is served as an input interface in the touch-control computer mouse (1) of the present invention, the potential at the contact point may vary with pressure change or shaking of the hand to produce noise current. Therefore, RC averager circuit is utilized to eliminate noise and stabilize the output. Referring to the high-low speed averager (243) of FIG. 4, RF is high-speed average resistance, RS is low-speed average resistance, C2 is average capacitor, SW3 is high-low speed averager control switch, SW1 is x, y axis communication mode selection switch. Because circuit reaction speed is slower at the front stage of a contact signal, a high-speed averager is used for the front segment of a contact signal wave form and a low-speed averager is used for the end segment of the contact signal wave form to allow to the contact signal wave form be well filtrated for further accurate determination by the single-chip microprocessor.
The voltage reader (244) utilizes the timer and the selector switch SW4 of the single-chip microprocessor (245), the voltage of the VTOP and the ramp generator of the constant voltage circuit and ramp generator (242) to read the corresponding voltage value of the contact position detector (241) at x-axis, y-axis average resistance (2101), (2111). The operation is outlined hereinafter. SW4 is to act at VTOP and SW2 is grounded to allow the capacitor C1 discharge to zero potential to in turn allow the timer of the single-chip microprocessor (245) be reset. Then the timer of the single-chip microprocessor is started, the SW2 switches on the collector of the transistor Q3 to allow a constant current run to charge the capacitor C1. As soon as voltage VC≧VTOP, the output of the comparator (2442) becomes "1". The timer of the single-chip microprocessor (245) is stopped immediately, and the total count of the timer becomes Ttop. In the same manner, when SW4 is switched to the contact potential VX of the x-axis or the contact potential VY of the y-axis after wave form filtration, the value for TX and TY can also be obtained. From the value of Ttop, TX and TY, the position of contact points Xt1, Yt1, Xt2, Yt2, . . . can thus be obtained; from the value of Xt2-Xt1, Yt2-Yt1, the direction and amount of the shifting of contact point can be determined; and Xt1=Tx1/Ttop, Yt1=TY1/Ttop . . . Xtn=Txn/Ttop, Ytn=Tyn/Ttop.
In the present invention, the above-described circuit is used to match with a single-chip microprocessor (245), a function selector switch (246) and one series of input-output and power circuit (247). Therefore, in addition to the function that a regular computer mouse provides, a lock key may be further used to draw lines directly through the face panel of the present invention. Because no additional power cable is required, power saving and dust protective requirements can be efficiently achieved.
Reference is made to the flow chart of FIG. 5 which illustrates the operational process of the present invention. When the present invention is connected to a PC or communication equipment, signal processing circuit checks if the finger drawing process starts. It continues to check the signal if the answer is negative. If the answer is positive, it reads the voltage value of t1 (first touch) and then checks if further finger drawing is still continuously performing. If the answer is negative, it jumps back to start. If the answer is positive, it starts to read the voltage value of t2 (finger touch at the second time) and compare the voltage value of t2 with t1. If the value of t2 is equal to the t1, it returns to the start to check the finger touch signal. If the voltage value of t1 (the first) is smaller than t2 (the second), the amount of variation is reducing; if the voltage value of t2 (the second) is smaller than t1 (the first), the amount of variation is increasing. The data is further transmitted to the communicated computer equipment, the voltage of t2 (the second) is then designated as the voltage of t1 (the first) and it returns to judge if drawing signal is still continuing at t2.
The description mentioned above is deemed the best mode that the inventor can anticipate during preparing of his invention. Any person who is skilled in the art can make changes and revisions without departing from the spirit of this invention. | A touch-control mouse provides rapid and accurate control of the positioning of a cursor on a computer display screen, and includes a laminated touch-control film assembly, an aluminum supporting board, a press button switch set, a signal processing circuit board, and a dust-protective hanging case. Drawing using a finger on x-axis and y-axis resistance planes of the laminated touch-control film assembly results in variable potential value for x, y coordinates. The value of potential variation is calculated through a single-chip microprocessor to indicate relative direction, speed and amount of displacement on x, y coordinates. The signal of the relative direction, speed and amount of displacement is further is further sent by the single-chip microprocessor through a standard RS-232 connector to one of the serial communications ports of a PC to rapidly and accurately control the positioning of the cursor on the computer display screen. | 6 |
BACKGROUND OF THE DISCLOSURE
[0001] 1. Field of the Invention
[0002] The present invention is directed to a glass fiber web and a process of making that glass fiber web. More specifically, the present invention is drawn to a glass fiber web and a wet-lay process for making the web wherein the glass fibers are sized in a manner providing sufficient wet strength so that glass fibers on a drying conveyer can be transmitted to an adjacent binding conveyer without glass fiber dropout.
[0003] 2. Background of the Prior Art
[0004] The standard process for preparing glass webs useful in many applications such as substrates in the formation of building materials, e.g. roofing membranes, high strength fabrics and the like, is the wet lay process. A major problem associated with the preparation of glass fiber mats by the wet lay process is the lack of strength of the wet individual glass fibers in the drying step prior to the binding step. That is, individual glass fibers disposed on a moving conveyer, subsequent to white water treatment, where substantial drying occurs, but prior to transfer to a downstream moving conveyer, where binding occurs, fall off the drying conveyer due to insufficient strength of the glass fibers.
[0005] A prior art method of overcoming this problem has been to provide a hiatus between the drying and binding steps. That is, the glass fibers, after separation in the white water treatment step, are allowed to dry for a few days before being binded into webs. Although this expedient is effective, it obviously markedly slows down the glass fiber web manufacturing process and is thus undesirable.
[0006] The above remarks, when taken with representative prior art summarized below, establish a strong need in the art for a new glass fiber web prepared by a wet lay process in which the strength of glass fibers have adequate strength so that the problem of loss of glass fibers between the drying and binding steps is overcome.
[0007] U.S. Pat. No. 4,871,605 describes a wet lay process for preparing a glass fiber mat useful as a roofing shingle. However, this patent does not address the aforementioned problem of the wet lay process of preparing fiber glass mats. This is all the more surprising insofar as a principal utility of glass fiber mats, prepared in accordance with the process of the '605 patent, is as a substrate in the formation of roofing shingles.
[0008] U.S. Pat. No. 6,228,281 sets forth a sizing composition for coating glass and carbon fibers. There is no disclosure in this patent of utilizing the sizing composition in a wet lay process.
BRIEF SUMMARY OF THE INVENTION
[0009] A new glass fiber mat and a process of making that web has now been developed in which the glass fibers of the web are possessed of the requisite strength so that individual glass fibers are not lost, due to drop off, between the drying and binding steps, in a wet lay process of making a glass fiber mat.
[0010] In accordance with the present invention a glass fiber web is provided. The glass fiber web comprises glass fibers sized with a sizing composition which includes a partially amidated polyalkylene imine cationic lubricant randomly dispersed in a cured thermosetting resin.
[0011] In further accordance with the present invention a wet lay process is provided for preparing a glass fiber web. In this process glass fibers are sized with a sizing composition which includes a cationic lubricant, the cationic lubricant being a partially amidated polyalkylene imine. The sized glass fibers thus formed are separated by immersing the sized glass fibers in an aqueous dispersant medium wherein an aqueous slurry is formed. The resultant individual separated glass fibers are removed from the aqueous slurry and dried. The dried glass fibers are thereupon binded together by means of an uncured thermosetting binding agent. A glass fiber web is formed by curing the thermosetting binding agent.
DETAILED DESCRIPTION
[0012] Glass fibers having a length of between about 0.25 inch and about 3 inches, preferably, between about 0.5 inch and about 2 inches, and more preferably, between about 1 inch and about 1.5 inches are employed in the glass fiber web of the present invention. The glass fibers within the scope of the present invention have a diameter of between about 10 microns and about 20 microns. More preferably, the glass fiber diameter is in the range of between about 13 microns and about 17 microns.
[0013] Glass fibers having the aforementioned dimensions are contacted with a sizing composition subsequent to glass fiber attenuation from a bushing apparatus. The sizing composition of the present invention includes a cationic lubricant which is a partially amidated polyalkylene imine having a preferred residual amine value of from about 200 to about 800. The partially amidated polyalkylene imines employed in the sizing composition are reaction products of a mixture of fatty acids containing between about 2 and about 18 carbon atoms and a polyethylene imine having a molecular weight of from about 800 to about 50,000. The amines suitable for forming the fatty acid salt of this reaction product are preferably tertiary amines of low molecular weight. For example, a preferred tertiary amine is a nitrogen atom attached to alkyl groups having from about 1 to about 6 carbon atoms. Preferably, the fatty acid moiety of the salt includes from about 12 to about 22 carbon atoms. More preferably, the partially amidated polyalkylene imine is a condensation reaction product of a polyethylene imine and a fatty acid selected from the group consisting of pelargonic and caprylic acids. An example of a cationic lubricant meeting the above criteria is Emery 6760T® available from Henkel Inc.
[0014] The concentration of the cationic lubricant in the sizing composition of the present invention is preferably in the range of between about 0.005% to about 0.20% by weight, based on the total weight of the sizing composition. The remaining constituency of the sizing composition is standard. That is, the sizing composition includes a film-forming polymer well known in the art for the coating of glass fibers. For example, film-forming polymers useful in the sizing composition of the present invention includes polyvinyl alcohols, polyvinyl acetates, epoxies, polyamides, polyesters, styrenated acrylics, phenolics, melamines, nylons, acrylics, polyvinyl chlorides, polyolefins, polyurethanes, nitrile rubbers and the like. Of these polymers, polyvinyl alcohols are particularly preferred.
[0015] The sizing composition also includes a coupling agent. The coupling agent employed in the sizing composition of the present invention has hydrolyzable groups that can react with the glass surface of the fibers to remove unwanted hydroxyl groups as well as groups that can react with the film-forming polymer to chemically link the polymer with the glass surface. Preferably, the coupling agent has one to three hydrolyzable functional groups that can interact with the surface of the glass fibers. In addition, the coupling agent includes one or more organic groups that are compatible with the polymer matrix.
[0016] Preferred coupling agents, useful in the sizing composition of the present invention, include organosilanes. Suffice it to say, the organosilanes useful in the sizing composition are preferably those that produce one to three hydroxyl groups for bonding at the inorganic glass surface to form O—Si—O bonds and which also possess at least one organic group for binding to the matrix resin. Preferred examples of organosilanes useful in the present invention include 3-amino-propyldimethylethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, β-aminoethyltriethoxysilane, N-β-aminoethylaminopropyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, vinyl-trimethoxysilane, vinyl-triethoxysilane, allyl-trimethoxysilane, mercaptopropyltrimethoxysilane, mercaptopropyltriethoxysilane, glycidoxypropyltrimethoxysilane, 4,5-epoxycyclohexylethyltrimethoxysilane, ureidopropyltrimethoxysilane, ureidopropyltriethoxysilane, chloropropyltrimethoxysilane and chloropropyltriethoxysilane and mixtures thereof.
[0017] Additional lubricants can be added to the sizing composition to facilitate contact between the sizing composition and the glass fiber surface. Conventional lubricants known to those skilled in the art which are compatible with the components of the sizing composition of the present invention may be utilized. The concentration of the lubricants is usually small. A preferred lubricant is a fatty acid tallow amine such Cat-X®.
[0018] A hydrolyzing agent may also be included in the sizing composition. The hydrolyzing agent, which acts to hydrolyze the coupling agent or agents, is preferably an acid. Preferred hydrolyzing acids include hydrochloric, acetic, formic, citric, oxalic or phosphorous. Of these, acetic acid is more preferred.
[0019] The concentration of sizing composition provided onto the glass fiber is referred to as loss on ignition (LOI). The glass fiber employed in the glass fiber web of the present invention is characterized by a LOI in the range of between about 0.01% and about 0.75%, said percentages being by weight of the sizing composition, based on total weight of sized glass fibers free of water. More preferably, the LOI is in the range of between about 0.05% and about 0.5% by weight. Still more preferably, the LOI is in the range of between about 0.1% and about 0.2% by weight.
[0020] The thus formed sized glass fibers, in the form of chopped bundles, has a moisture content of about 10% to about 20%. These sized glass fibers are thereupon added to an aqueous dispersant medium to form an aqueous slurry. The aqueous dispersant includes an emulsifier to generate entrained air when the slurry is thereupon agitated. This entrained air imparts a white color to the slurry and thus the slurry is referred to as “white water.” This agitation of the aqueous slurry separates the glass fibers into individual strands.
[0021] The recovered individual glass fiber strands are thereupon dried. The drying step is effectuated by collecting the wet, sized glass fibers on an endless moving conveyer, the conveyer preferably being a wire screen. As the glass fibers move on the endless conveyer, they are heated and vacuumed to remove water. By the time the wet glass fibers traverse the length of the endless conveyer, the drying step is completed.
[0022] Immediately subsequent to the drying step, the binding step is initiated. This step involves transfer of the dried glass fibers, coming off the drying endless conveyer, onto an adjacent endless moving binding conveyer. It is at this point that the advantage of the present invention is manifested. In the past, an unacceptable percentage of glass fibers, if not allowed to dry for up to a few days after separation, fell into the space between the drying and binding conveyors. However, the sized glass fibers of the present invention attach to each other to provide the requisite strength so that glass fiber drop off is substantially reduced or eliminated between drying and binding conveyers.
[0023] The binding step, which occurs on the binding conveyer, involves application of a suitable thermosetting resin, which acts as the binder to the dried, sized glass fibers. The requisite amount of binder is preferably applied by curtain coating, which is the term used in the art for flooding, and vacuuming off the excess binder so that the desired binder concentration is obtained.
[0024] The binding resin, as stated above, is a thermosetting resin. Any suitable thermosetting resin, which is compatibly cured in the presence of glass fibers, may be utilized. In the interest of economy, a low cost thermosetting resin, such as urea formaldehyde, is preferred.
[0025] By the time glass fibers traverse the length of the binding endless conveyor, the desired concentration of glass fiber and binder is present. At this point the glass fiber-binder mixture is cured at a temperature at which the thermosetting resin crosslinks. Usually, this temperature is at least about 175° C.
[0026] The following examples are given to illustrate the present invention. Because these examples are given for illustrative purposes, the invention should hot be deemed limited thereto.
EXAMPLE 1
[0027] A sizing composition was prepared comprising 0.1% polyvinyl alcohol; 0.02% ureidosilane; and 0.05% partially amidated polyalkylene amine, specifically, Emery 6760T®, wherein the percentages are by weight, based on the total weight of the composition. The remainder of the composition was water.
[0028] The aforementioned sizing composition was coated on a specially prepared glass fiber mat handsheet. The handsheet was thereupon moisture saturated and vacuumed. The handsheet was laid over a round opening and a load was placed on the handsheet so that the handsheet moved below the round opening. The load was increased until the handsheet reached a vertical distance of 24 mm below the round opening. The wet elongation strength was the weight of the load that is required to reach this distance. Obviously, the heavier the weight the stronger is the wet elongation strength.
[0029] It is apparent that the wetter the handsheet the less strong is the handsheet. The aforementioned test was conducted twice. The first test occurred on the day that the handsheet was moisture saturated. As such, testing on this day results in the maximum weight required since the saturated moisture content weakens glass fiber strength.
[0030] A second identical test was conducted three weeks later on the 21 st day after moisture saturation. During this 21 day period the glass fiber mat handsheet dries, reducing the moisture content and thus increasing wet elongation strength.
[0031] The results of this test was surprisingly found to be 153 grams on Day 1 and 149 grams on Day 21.
[0032] These results are summarized in the Table below.
EXAMPLES 2-6
[0033] Five additional sizing compositions, employing the same components, albeit in varying concentrations, were prepared. These sizing compositions were applied, in the same concentration as in Example 1, to glass fiber mat handsheets identical to those used in Example 1. These handsheets were tested on Day 1 and Day 21 in a fashion identical to that employed in Example 1.
[0034] The results of these tests, including the constituency of the aqueous sizing compositions, are reported in the Table.
COMPARATIVE EXAMPLE 1
[0035] Example 1 was repeated but for the constituency of the sizing composition. The sizing composition, although containing polyvinyl alcohol and ureidosilane, utilized a typical cationic lubricant of the prior art, instead of employing the partially amidated polyalkylene imine of the present invention. These components were included in the sizing composition in concentrations similar to the concentration of the examples of the present invention.
[0036] The results of the comparative example are included in the Table.
TABLE Example No. 1 2 3 4 4 4 CE1 Sizing Composition, % by wt Polyvinyl alcohol 0.1 0.1 0.1 0.1 0.1 0.1 Ureidosilane 0.02 0.02 0.02 0.04 0.04 0.04 Partially amidated 0.05 0.1 0.15 0.05 0.1 0.15 polyalkylene imide Wet web strength, g. Day 1 153 152 166 166 155 158 68 Day 21 149 151 143 154 145 137 106
Discussion of Results
[0037] The wet strength handsheet test emulates the wet strength requirement of glass fibers moving from the drying conveyor to the binding conveyor. It is generally accepted that the wet strength requirement of glass fibers in moving from drying to binding conveyer is equivalent to a wet strength of approximately 100 grams, as determined in the aforementioned example.
[0038] The results of the above examples make it apparent that wet glass fibers, utilizing prior art sizing compositions, have to be stored up to 3 weeks in order to dry sufficiency to gain the requisite wet strength to successfully be processed. The sizing composition of the present invention eliminates this delay by increasing the wet strength of fully moisturized sized glass fibers such that no delay, occasioned by drying, is required before converting the glass fibers into glass fiber mats.
[0039] The above embodiments and examples are provided to illustrate the scope and spirit of the present invention. These embodiments and examples will make apparent, to those skilled in the art, other embodiments and examples. These other embodiments and examples are within the contemplation of the present invention. Therefore, the present invention should be limited only by the appended claims. | A glass fiber web and a wet lay process of making the glass fiber web. The glass fibers of the web include glass fibers sized with a sizing composition which includes a partially amidated polyalkylene imine cationic lubricant randomly dispersed in a cured thermosetting resin. The wet lay process includes the steps of so sizing the glass fibers followed by separating such fibers by immersing the glass fibers in an aqueous dispersant medium to form an aqueous dispersion which is agitated. The separated sized glass fibers are dried. The dried, sized glass fibers are then bound with the thermosetting resin binder. The curing of the binder produces the product glass fiber web. | 3 |
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates generally to shock absorbers and, more particularly in some non-limiting embodiments, to a variable dampening speed piston head assembly for an R/C (Radio controlled) car shock absorber.
Background
The sport of R/C vehicle racing is highly competitive. Professional drivers of R/C vehicles who race at the upper levels of the sport are well paid by sponsors. Engineers and hobbyists have worked for decades to constantly improve performance of R/C vehicles in every aspect of operation including motors, tires, weight, construction, shock absorbers, and the like. R/C vehicle enthusiasts are constantly searching for improved performance. Even small changes that can improve performance of lap speed by fractions of seconds are highly desirable and sought after. However, given the long term intense competition and efforts for improvements in this field, it is somewhat unusual to find improvements that reliably improve lap speed by one-half second or more. Moreover devices that do provide performance improvements are often complex and inconsistent or prone to being less robust than desirable. Devices that provide improved performance in a manner that is readily repeatable and reliable are highly sought after.
Shock absorbers are commonly used in R/C vehicles and are commonly used in conjunction with springs in a variety of applications, particularly vehicles, bicycles, and the like, to control suspension movement by absorbing and dissipating energy during travel. Fluid-filled shock absorbers are one common type of shock absorber wherein a piston fastened to a piston rod travels through fluid in the bore of the piston cylinder. Another common type is similarly constructed, but with a gas instead of a fluid housed within the piston cylinder.
When a vehicle encounters a bump or uneven terrain, the suspension compresses during the compression stroke. After completing the compression stroke, the suspension responds by returning to its original position during the rebound stroke. Valves on the piston head restrict the flow of oil through the piston, causing more pressure to be created in front of the piston then behind it. The pressure differential creates the damping force needed to resist the uncontrolled movement of the piston and associated spring. The desired number of valves for the piston head changes depending on the terrain in which the vehicle will travel, the desired responsiveness of the vehicle, and the like. It would be desirable to have a piston assembly that would be adaptable to respond effectively to a variety of environments.
In the R/C car setting, shock absorbers provide a similar function but on a much smaller scale, which leads to unique problems specific to the R/C car application, including product materials, size difficulties, and the like. Tapered pistons and wafer pistons are just two of many alternatives that have been advanced to combat the problems outlined above. Examples of background patents and publications in the general area of shock absorbers include:
U.S. Pat. No. 4,620,619, issued Nov. 4, 1986, to Emura et al., discloses a variable-damping-force shock absorber such that the damping force determined through an orifice selected by an orifice adjuster according to the driver's preference can further automatically be increased during extension for improvement in road-holding ability and decreased during compression for improvement in riding comfort. The shock absorber according to the present invention comprises an annular member formed with an orifice and a disk valve disposed on top of the annular member. During extension, the disk valve is closed for allowing fluid to by-pass through an orifice of the annular member; during compression, the disk valve is opened for additionally allowing fluid to by-pass through the annular member. Further, since the various elements for adjusting the damping force are completely housed within the piston rod, it is possible to increase the stroke of the piston rod.
U.S. Pat. No. 4,775,038, issued Oct. 4, 1988 to Unnikrishnan et al., discloses a piston valving and seal mechanism for a fluid shock absorbing device. A piston is mountable on a piston rod of the device. The piston has an outer periphery, rebound chamber face and compression chamber face. A piston seal is movably mounted in a groove where the piston rebound chamber face and outer periphery meet. The seal is adjacent compression passages in the outer periphery. A seal retainer plate along the piston rebound chamber face with a backing spring bias the seal. The plate is raised from the rebound chamber face and includes passages through the plate for fluid flow through the plate and into underlying recoil passages in the piston. The seal acts as a check valve for the compression passages. A separate recoil passage valve plate on the compression chamber face, with a backing spring, acts as a valve for the recoil passages.
U.S. Pat. No. 4,809,828, issued Mar. 7, 1989 to Nakazato, discloses a one-way damping valve mechanism in a hydraulic damper having a first hydraulic chamber defined in a cylinder, and a piston rod having an inner end on which there is mounted a piston slidably fitted in the cylinder, divides the first hydraulic chamber into a second hydraulic chamber and a third hydraulic chamber. The valve mechanism produces a damping force when the piston is moved in a prescribed direction to move working oil from the second hydraulic chamber into the third hydraulic chamber. The valve mechanism comprises a subvalve for defining a first hydraulic passage to generate a damping force when the piston moves at an extremely low speed in the prescribed direction, and a main valve for defining a second hydraulic passage to generate a damping force when the piston moves in a medium/high speed range in the prescribed direction.
U.S. Pat. No. 6,540,052, issued Apr. 1, 2003 to Fenn et al., discloses a Damping-valve body, in particular for a piston-cylinder unit filled with damping fluid, having separate passages for two directions of flow, at least some of the passages having an outlet opening that is at least partially covered by at least one valve disk. Each passage has a rib that extends radially, relative to a first direction of flow of the damping fluid, from a boundary wall of the passage and bears a valve support surface for the at least one valve disk.
U.S. Pat. No. 7,040,468, issued May. 9, 2006 to Shinata, discloses a hydraulic shock absorber includes a cylindrical housing within which a piston assembly is slidably received. The piston assembly includes a piston element connected to a piston rod and adapted to divide an interior of the housing into compression and rebound chambers. The piston element has compression and rebound passages to provide fluid communication between the compression and rebound chambers. A valve assembly includes a first valve disc positioned on a lower side of the piston element, and a second valve disc retained on the first valve disc. The second valve disc includes apertures arranged in a circumferentially spaced relationship and are selectively openable and closeable by the first valve disc. A third valve disc is retained on the second valve disc and has notches arranged in a circumferentially spaced relationship. The notches cooperate with the apertures to collectively form ports. The ports are communicated with the compression chamber. A fourth valve disc cooperates with the second valve disc to sandwich the third valve disc so that restrictive orifices are defined in an outer end of the notches. Each of the ports has a cross sectional area greater than that of the restrictive orifices regardless of a relative angular position between the second and third valve discs.
U.S. Pat. No. 7,213,689, issued May 8, 2007 to Chang, discloses a shock absorber for a remote-controlled model car includes a sealing member fixed on the topside of a piston. The sealing member has two opposite flexible portions respectively matching with the flow-guiding holes of the piston, with flow gaps formed between the flexible portions and the upper outer sides of the piston. The flow gap, matching with the extent of an external force imposed upon the shock absorber, can be properly diminished or closed up. Each flexible portion is bored with a flow-adjusting hole smaller than and aligned to the flow-guiding hole of the piston for reducing the flow amount of liquid oil flowing through the flow-guiding hole. When pressed by different-extent external forces, the shock absorber can automatically adjust its buffering force to an excellent condition by adjustment of the flow-adjusting holes and the flow gaps.
U.S. Pat. No. 7,310,876, issued Dec. 25, 2007 to May et al., discloses a method for producing a one-part piston body for a piston-cylinder arrangement, in particular a shock absorber piston, is disclosed. The method may include in a first step, pressing a green compact comprising a revolving web and longitudinal support webs from a sinterable metallurgical powder. In a second step, the green compact may be sintered to form a blank. In a third step, radially disposed stamping tools may be used to form, under material displacement, transverse grooves into at least a part of the support webs through cold deformation. In a fourth step, the blank provided with transverse grooves may be calibrated to its final form through pressing with calibrating tools.
U.S. Pat. No. 8,083,039, issued Dec. 27, 2011 to Vanbrabant, discloses a disc valve assembly for a shock absorber opens due to axial movement of a valve disc. The valve disc is biased against a valve body by a valve spring. The valve spring is designed to provide a circumferentially asymmetrical load biasing the valve disc against the valve body. The disc valve assembly can be used as a piston rebound valve assembly, a piston compression valve assembly, a base valve compression valve assembly or a base valve rebound valve assembly.
U.S. Pat. No. 8,235,188, issued Aug. 7, 2012 to Kais, discloses a damping element for a vibration damper that works with hydraulic fluid. The fundamental structure of the damping element includes a one-piece base body configured as a circular disk, which has a plurality of first flow-through openings, each having an entry cross-section in a first face side of the base body, as well as a plurality of second flow-through openings, each having an entry cross-section in an opposite, second face side of the base body, as well as circular valve disks on both face sides of the base body, which rest against a support surface of the base body, disposed in the center, and at least partially close off exit cross-sections of the flow-through openings. The exit cross-sections are surrounded by control edges, which form contact surfaces for the valve disks and project beyond the support surface as well as the entry cross-sections. The height of the control edges increases with an increasing radial distance from the center point of the base body in the form of a circular disk. According to the invention, the flow-through openings have a flow channel section that is preferably cylindrical and opens into a larger exit cross-section bordered by the control edges.
United States Patent Application No. 2013/0180813, published Jul. 18, 2013 to Moore, Jr., discloses a shock absorber configured to mount within a remote control vehicle. The shock absorber includes a cylindrical housing, a piston rod, and an acircular piston head. The piston head includes a plurality of substantially flat surfaces disposed on sides of the piston head that form bypass gaps between the piston head and the cylindrical housing. The acircular piston head includes a plurality of bypass apertures disposed through the piston head in an angularly asymmetrical configuration. The acircular piston head is generally octagon shaped. The acircular piston head includes a plurality of spaced arcuate edges sized to come in contact with an interior surface of the cylindrical housing. The shock absorber includes a plurality of bypass valves formed by cooperative operation of a shim coupled against the bypass apertures, such that fluid is permitted to flow through the bypass valves in a first direction and is restricted in a second direction.
United States Patent Application No. 2013/0180813, published Sep. 12, 2013 to Ericksen et al., discloses a vehicle damper comprising a fluid filled cylinder, a piston for movement within the cylinder, at least two fluid ports formed in the piston and at least one shim at least partially blocking the ports. In one embodiment, a fluid collection area is formed between the ports and the shim, the collection area permitting communication between fluid in the ports. In another embodiment, the piston includes at least one aperture constructed and arranged to receive a threaded bleed valve.
Many efforts have been made to improve the operation of all components of R/C vehicles including the relatively small size shock absorbers of R/C vehicles. Consequently, those skilled in the art will appreciate the present invention that addresses the above and other problems.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an improved R/C shock absorber that improves racing lap times.
Another possible object of the present invention is to provide an improved piston head assembly for R/C shock absorbers that improves racing performance.
Another possible object is to provide an improved piston head assembly for R/C shock absorbers with variable damping force.
Yet another possible object of the present invention is to provide a reliable and simplified piston for R/C shock absorbers which provides for a variable compression damping force to reliably improve lap times.
Yet another possible object of the present invention is to provide valve members that can be utilized in conjunction with the valve members shown in my previous application Ser. No. 14/631,190, filed Feb. 25, 2015. For simplicity the valve members of my previous application are not shown but are simply mounted in conjunction.
In accordance with the disclosure, one embodiment of the present invention may include, but is not limited to, a variable dampening speed piston head assembly for an R/C shock absorber, the R/C shock absorber comprising a piston rod, a piston cylinder, and fluid within the piston cylinder, the variable dampening speed piston head assembly comprising: a piston head with a round periphery and defining a plurality of variable valve holes to permit two-way fluid flow through the piston head when the piston head reciprocates in the piston cylinder; a dampening member comprising a central portion with a hole therethrough and a plurality of valve members extending radially outwardly from the central portion; a fastener to secure the dampening member and the piston head to the piston rod whereby the plurality of valve members are oriented to engage each of the plurality of variable valve holes to thereby form a plurality of variable valves in the piston head; and the plurality of valve members being mounted to be moveable between a first position relative to the valve holes and a second position relative to the valve holes, in the first position the plurality of valve members being positioned further from the valve holes to allow greater fluid flow through the valve holes than in the second position where the valve members permit a lesser fluid flow through the valve holes.
The plurality of valve members are moveable between the first position and the second position only during a compression stroke.
The plurality of valve members are bendable to move between the first position and the second position.
The plurality of valve members are bendable in response to speed of movement of the piston head in a direction of a compression stroke, the plurality of valve members being responsive to bend to a greater degree in response to a greater speed of the compression stroke than a lesser speed of the compression stroke.
The plurality of valve members may be bendable from the first position to the second position in response to a fall of the R/C vehicle from no more than six inches, no more than eight inches, no more than ten inches, or no more than eleven inches.
The plurality of valve members may be substantially flat from a side view in the first position.
The plurality of valve members are bent so that an end of the plurality of valve members engages the piston head in the second position. In another embodiment, the plurality of valve members are bent so that an only an outermost end of the plurality of valve members engages the piston head in the second position.
The dampening member further comprises a Delrin®, or non-oriented or spun carbon fiber.
The apparatus may further include a recess in the piston head with the dampening member at least partially engaged within the recess.
The recess may include a plurality of scalloped portions corresponding with each of the plurality of valve holes, the plurality of scalloped portions having a thickness less than that of the piston head.
The apparatus may further include at least one self-centering ridge on the piston head.
In accordance with the disclosure, another embodiment may include, but is not limited to, a method for manufacturing a variable dampening speed piston head assembly for an R/C shock absorber, the R/C shock absorber comprising a piston rod, a piston cylinder, and fluid within the piston cylinder, the variable dampening speed piston head assembly.
The steps include providing a piston head with a round periphery and defining a plurality of variable valve holes to permit two-way fluid flow through the piston head when the piston head reciprocates in the piston cylinder, providing a dampening member comprising a central portion with a hole therethrough and a plurality of valve members extending radially outwardly from the central portion, and securing a fastener to the dampening member and the piston head to the piston rod whereby the plurality of valve members are oriented to engage each of the plurality of variable valve holes to thereby form a plurality of variable valves in the piston head.
A final step is mounting the plurality of valve members to be moveable between a first position relative to the valve holes and a second position relative to the valve holes, in the first position the plurality of valve members being positioned further from the valve holes to allow greater fluid flow through the valve holes than in the second position where the valve members permit a lesser fluid flow through the valve holes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view, partially in section, of a piston head assembly in an R/C shock absorber during a first compression stroke in accord with one possible non-limiting embodiment of the present invention.
FIG. 2 is an elevational view, partially in section, of a piston head assembly in an R/C shock absorber during a second compression stroke in accord with one possible non-limiting embodiment of the present invention.
FIG. 3 a top view of a piston head assembly for an R/C shock absorber in accord with one possible non-limiting embodiment of the present invention.
FIG. 4 is a top view of another piston head assembly for an R/C shock absorber in accord with one possible non-limiting embodiment of the present invention.
The above general description and the following detailed description are merely illustrative of the generic invention, and additional modes, advantages, and particulars of this invention will be readily suggested to those skilled in the art without departing from the spirit and scope of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIG. 1 and FIG. 2 , piston head assembly 100 is disposed within piston cylinder 60 with the piston cylinder operably attached to a spring (not shown) for the suspension system. This type of spring and piston cylinder suspension system is well known in the art. The movement of the shock absorber and spring is dependent on the force encountered by the suspension, and the damping force is selected to best keep the R/C car wheels supported completely on the ground during the suspension travel. The improvements to the piston head of the present invention as described herein act to greatly enhance operation of the suspension system especially when compression occurs within the piston such as when the R/C vehicle lands from heights. The piston head 10 moves within fluid 80 that is in the cylinder as is known in the prior art.
FIG. 1 is a partial sectional elevational view of piston head assembly 100 in an R/C shock absorber during a first compression stroke in accord with the present invention. When an R/C car or vehicle lands from a jump that moves the piston very fast so that the chassis would hit the ground, for instance, the suspension reacts as depicted in FIG. 1 to slow movement of the piston. This is important to prevent the vehicle chassis from contacting the ground, thereby interrupting the intended and desired travel of the vehicle. Piston rod 40 and piston head 10 travel within piston cylinder 60 as indicated by arrow 90 when the car lands from the jump. Piston head 10 has a round shape which engages cylinder wall 82 , preventing fluid flow along the periphery of piston head 10 .
In this embodiment, dampening member 20 lies on top of piston 10 and is secured with fastener 30 , washer 32 , and washer 42 . In another embodiment, dampening member 20 may fit within a recess of piston head 10 so as to be flush with the surface of piston head 10 . Washer 32 is sized to cover dampening member 20 while allowing valve members 16 which extend radially outwardly (see also FIG. 2 ) the flexibility to bend as piston assembly 100 moves. Fastener 30 may comprise various fasteners suitable for connecting with rod 40 , including, but not limited to screws, nuts, and the like. In other embodiments, various alternative fastening arrangements may be utilized to secure piston head 10 to piston rod 40 consistent with the teachings of the present invention.
Accordingly, dampening member 20 comprises valve members 16 which extend radially outwards from dampening member body 20 corresponding with variable flow valve holes 14 . In this embodiment, variable flow valve holes 14 are formed within scalloped portions 18 which have a thickness less than the rest of piston or piston head 10 . When piston assembly 100 is moving fast as indicated at arrow 90 , valve members 16 flex as indicated in FIG. 1 to at least substantially restrict flow through variable valve holes 14 . Valve members 16 are bendable as depicted in FIG. 1 in response to a fall of an R/C vehicle from no less than six inches. In other embodiments, valve members 16 are responsive to falls from no less than eight inches, ten inches, or eleven inches.
In another embodiment, piston 10 may further comprise a plurality of one way holes that only allow fluid travel in one direction (Not shown—see my previous U.S. application Ser. No. 14/631,190, which is incorporated in its entirety herein). In that embodiment, which is readily utilized in conjunction the with present invention, reduced flow always occurs during compression of the piston as compared with greater flow during movement of the opposite way allowing quicker rebound. Dampening member 20 is simply mounted in conjunction with the member of my previous invention.
In some embodiments, valve members 16 may flex sufficiently to contact scalloped portions 18 and variable valve holes 14 to restrict more flow, while in other embodiments valve members 16 may bend less but still inhibit flow through valve holes 14 as shown at arrows 73 . Regardless, fluid is still able to flow through variable valve holes 14 during compression because of the decreased thickness of scalloped portions 18 as compared to piston head 10 allowing fluid to surround valve members 16 and pass through valve holes 14 as indicated at arrows 53 , 43 . In other words, flow through variable flow valve holes 14 is not completely blocked during compression. This is different from my previous invention, which completely blocks compression through some openings in the valve during and allows greater flow during the rebound. Preferably, valve members 16 extend in a symmetrical way from dampening member body 20 so that the forces produced by operation of the one-way valves do not cause tilting of piston head 10 during operation.
In a preferred embodiment, dampening member 20 is made of a material that is both sufficiently rigid and resilient to be suitable to be able to withstand the shock and wear of normal operation to prevent disintegration inside piston cylinder 60 . In one possible preferred embodiment, dampening member 20 could be constructed of Delrine®, or non-oriented or spun carbon fiber. However, other resilient, rigid materials could be used consistent with the teachings herein. In a preferred embodiment, the material is selected to allow a range of operation between at least anticipated ambient temperatures.
FIG. 2 is another partial sectional elevational view of piston head assembly in a piston assembly 100 during a second compression stroke as indicated at 92 in accord with one embodiment of the present invention. However, in this figure, the piston is moving at a slower rate than in FIG. 1 . For instance, the R/C car may encounter a bump in the road, wherein the high fluid flow allows the wheels to follow the bump and maintain contact with the road, rather than bounce when encountering the bump. Thus, a variable flow valve is provided that varies the flow through the piston depending on the speed of movement acting on piston 10 . In the slower moving possibility of FIG. 2 , when piston 10 and piston rod 40 are moving within piston cylinder 60 as indicated by arrow 92 , the valve members 16 do not flex. Fluid flows through variable valve holes 14 just as described herein with regards to FIG. 1 . Accordingly, in this embodiment dampening member 20 and valve members 16 do not flex to substantially block variable valve holes 14 because piston assembly 100 is not traveling as quickly as in FIG. 1 . Valve members 16 are configured to bend to a greater degree in response to a greater speed of the compression stroke than a lesser speed of the compression stroke, so that valve members 16 do not flex at all on a relatively flat surface or with smaller bumps while also being responsive to differing racing conditions such as drops from heights when desired. During drops from heights the fluid flow is slowed so that the piston slows but does not bottom out.
Because valve members do not bend for relatively small movements, the relative increase in space in a comparison between FIG. 2 and FIG. 1 between valve members 16 and scalloped portions 18 increases the fluid flow through variable valve holes 14 as indicated by arrows 23 and 63 . The increased flow of fluid 80 through piston 10 provides for a normal operation for piston head assembly 100 with relatively smaller changes in the track. By providing different responses based on the speed of the compression stroke, piston head assembly 100 better maintains wheel contact with the road or track on the rebound stroke of the shock absorber.
FIG. 3 is a top view of piston head assembly 100 for an R/C shock absorber in accord with one possible embodiment of the present invention. The thickness of piston head 10 may typically be equal to or less than the thickness of the stock piston head assemblies provided with the R/C vehicles. Dampening member 20 defines central aperture through which fastener 30 extends for connecting piston head 10 and dampening member 20 to piston rod 40 utilizing washer 32 . Piston head 10 further comprises a plurality of two-way valve holes 12 surrounding the periphery to allow fluid flow in both directions in response to reciprocating movement of piston head 10 within piston cylinder 60 .
The number of two-way valve holes 12 depends on the R/C application for which piston head 10 is sought, as different shock absorbers have varying number of valves on the piston head as is known to those of skill in the art. Different users may prefer the use of different numbers of two-way valve holes 12 . In this embodiment, dampening member 20 fits within recess 19 with valve members 16 protruding into scalloped portions 18 partially restricting variable valve holes 14 . In another embodiment, dampening member body 20 may rest on the face of piston head 10 secured by fastener 30 . Scalloped portions 18 form a part of recess 19 and extend to the periphery of piston head 10 . In this embodiment, self-centering ridges 94 are formed on piston head 10 to divert the fluid encountered during suspension travel in a uniform fashion and prevent axial movement of piston head 10 during operation.
FIG. 4 is a top view of piston head assembly 100 A for an R/C shock absorber in accord with another possible embodiment of the present invention. In this embodiment, there are only three valve members 16 for dampening member 20 A. In this embodiment, dampening member body 20 A is secured to piston 10 by tabs 28 which may extend from piston 10 to hold dampening member 20 A in place, effectively forming a recess in which the dampening body resides. Furthermore, scalloped portions 18 may not be utilized so that the tabs hold dampening member 20 A and allow dampening member 20 A to be spaced from piston 10 . The operation is the same with the fluid flow through variable flow valve holes 14 to vary depending on the speed or acceleration or force acting on piston 10 during compression.
In a preferred embodiment, piston 10 is comprised of a plastic or hard composite material. In one embodiment, piston 10 has a diameter of less than three eighths inch. In another embodiment, piston 10 may have a diameter greater than one sixteenth inch, but less than one quarter inch. In one embodiment, the thickness of piston 10 is less than one-eighth of an inch.
The number of valve members 16 and variable flow valve holes 14 may range from one as to many as desired. Other arrangements for at least one valve member 16 and at least one variable valve holes 14 may be provided. While in this embodiment, a center portion of dampening member 20 is provided with a hole in the center, in another embodiment at least one valve member 16 may be offset from the center of the R/C piston and a center portion of the flexible member does not necessarily have a hole therethrough for connection with fastener 30 . Dampening member 20 or 20 A is preferably mounted on the top as shown (on an opposite side from the piston rod) and preferably is a single flexible member mounted on top of the piston as shown.
My previous application Ser. No. 14/631,190, filed Feb. 25, 2015, for piston head assembly for radio controlled shock absorber and method shows one-way valves in the piston head that may be utilized in conjunction with the present invention and is incorporated herein in its entirety. The valve members from my previous invention are not shown in the drawings herein for simplicity. However, the dampening member 20 of the present invention and those of my previous invention are both readily included in the same piston head and in a preferred embodiment both types of valves are utilized for improved operation.
As discussed in detail in my previous application, the valves in my previous application prevent flow through some openings in the valve head during compression and allow flow when the piston moves in the opposite way. Accordingly, in my previous application, a valve could effectively have four holes during compression and then eight holes during rebound and may be described in this way as four/ eight hole operation since users understand a piston with either four or eight hole valve openings of a selected size as used in the prior art making operation readily understood. Whereas, in the present invention, the valves act to reduce flow during fast compression but otherwise allow normal operation of the piston. Thus, the valves in my previous application are always operational whereas the valves in my present invention act as described herein to reduce flow during hard compression. The valve elements of the present invention may be mounted with and may be above the valves of my present invention and mounted and secured with fastener 30 and washer 32 . Recesses in the valve head provided by grooves, tabs, or the like, may or may not be utilized to assist in keeping the valve members such as valve member 16 of the present invention and valve members of the previous invention from rotating so as to maintain registration with valve openings. The valve members 16 and valve members of my previous members are spaced apart from each other on the piston.
In general overview of the drawings, it will be understood that such terms as “up,” “down,” “vertical,” and the like, are made with reference to the drawings and/or the earth and that the devices may not be arranged in such positions at all times depending on variations in operation, transportation, mounting, and the like. As well, the drawings are intended to describe the concepts of the invention so that the presently preferred embodiments of the invention will be plainly disclosed to one of skill in the art but are not intended to be manufacturing level drawings or renditions of final products and may include highly simplified conceptual views and exaggerated angles, sizes, and the like, as desired for easier and quicker understanding or explanation of the invention.
One of skill in the art upon reviewing this specification will understand that the relative size, orientation, angular connection, and shape of the components may be greatly different from that shown to provide illuminating instruction in accord with the novel principals taught herein. As well, connectors, component shapes, and the like, between various housings and the like may be oriented or shaped differently or be of different types as desired. Many additional changes in the details, components, steps, and organization of the system and method, herein described and illustrated to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention. It is therefore understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. | An apparatus and method for a piston head assembly for an R/C car shock absorber provides for variable dampening forces during compression movement based on how fast the piston is moving. During a first compression stroke, more fluid is allowed through the at least one variable valves, while during a second compression stroke faster than the first stroke, fluid movement is restricted through the at least one variable valves to quickly return the vehicle to proper riding position with respect to the road or track. | 1 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. Ser. No. 12/956,991, filed Nov. 30, 2010, which claims priority to and the benefit of U.S. provisional patent application Ser. No. 61/294,294, filed Jan. 12, 2010, and U.S. provisional patent application Ser. No. 61/323,064, filed Apr. 12, 2010, each entitled “Feature Tracking Using Ultrasound.”
TECHNICAL FIELD
[0002] This invention relates to methods for tracking features during a medical procedure.
BACKGROUND INFORMATION
[0003] One purpose of radiotherapy is to target a specified anatomical region suspected of having either gross or suspected microscopic disease (sometimes referred to as the clinical treatment volume, or “CTV”) with radiation while sparing surrounding healthy tissues and at-risk organs. Typically, a physician outlines the CTV on one or more planning images, such as a computed tomography (CT) image, magnetic resonance (MRI) image, three-dimensional ultrasound (3DUS) image, or a positron emission tomography (PET) scan. A treatment plan is then developed which optimizes the radiation dose distribution on the planning images to best accomplish the prescribed goals. The plan may be based on certain treatment parameters such as beam directions, beam apertures, dose levels, energy and/or type of radiation. The treatment is generally given in a finite number of fractions, typically delivered once a day. During treatment, the patient is positioned relative to the radiation beam prior to each fraction according to the treatment plan.
[0004] In practice, a margin is included around the CTV to account for anatomical changes in the CTV and surrounding areas. These changes can result from either interfractional motion, i.e., anatomical differences that develop immediately prior to the current fraction (often due to an inaccurate set-up or actual organ motion such as a different state of bladder fill), or from intrafractional motion, i.e., anatomical motion which occurs during the actual treatment delivery. In some instances, both types of motion may be present. In some instances, intrafractional motion may be cyclical, as caused by breathing, or random, as caused by gas or a steadily increasing bladder volume.
[0005] Some conventional image-guided radiotherapy (IGRT) applications may be used to track interfractional motion. Various imaging modalities may be used to implement IGRT, including three-dimensional ultrasound (3DUS) and x-ray imaging of fiducial “seeds” implanted in a patient's organ. Image capture is typically performed once prior to the radiation delivery, and the treatment couch is then adjusted to compensate for any changes in anatomy relative to the treatment plan. The use of IGRT to account for intrafractional motion, on the other hand, is in its infancy and requires continuous imaging throughout the treatment. As trends in radiotherapy begin to move towards fewer fractions and longer treatment times, correcting for intrafractional motion is growing in importance.
[0006] One method of tracking intrafractional motion uses x-rays to image fiducials at discrete points in time throughout treatment. However, continuous monitoring is not achievable with this methodology because the x-ray imaging exposure is unbearably high, with an image frequency of 30 seconds being the currently acceptable limit. Such procedures still require undesirable extra radiation as well as an invasive fiducial implantation procedure. Further, various surface monitoring technologies have been developed for cyclical intrafractional motion, but these do not provide internal information and are not sufficient in many applications, particularly when random motion occurs. Yet another technology uses beacons which are implanted in the feature of interest, and tracked in real-time using electromagnetic methods. As with fiducials, this procedure also requires an invasive implantation procedure.
[0007] Two-dimensional ultrasound (2DUS) can conceivably be proposed for intrafractional motion detection as it is real-time in nature, does not add radiation exposure to the patient during the monitoring process, and does not require implantation of fiducials. Temporally-spaced 2DUS images, as well as three-dimensional ultrasound (3DUS) images, have been proposed to track intrafractional motion during radiotherapy. See, for example, Xu et al, Med. Phys. 33 (2006), Hsu et al, Med. Phys. 32 (2005), Whitmore et al, US 2006/0241143 A1, Fu et al, US 2007/0015991 A1, and Bova et al, U.S. Pat. No. 6,390,982 B1. Some of these disclosures discuss the use of 3DUS probes to obtain a “four-dimensional” image series, however, there remain many obstacles in obtaining and using these images which are not addressed in the current literature.
[0008] One conventional three-dimensional (3D) probe utilizes a motorized two-dimensional (2D) probe placed inside a housing that sweeps mechanically within the housing, thus collecting a series of two-dimensional slices to cover the three-dimensional volume. For example, imaging a 10 cm×10 cm area at a given depth using a resolution of 0.5 mm, each sweep requires 200 slices. At a framerate of 20 Hz, one sweep takes approximately 10 seconds to complete, which precludes effective “real-time” four-dimensional imaging (three physical dimensions changing over time). Moreover, reconstruction of the entire three-dimensional volume takes at least two seconds which further reduces the theoretical three-dimensional refresh rate to 12 seconds, although multi-thread processing may help. Anatomical feature extraction based on the three-dimensional images is also time consuming and requires at least an additional five seconds. Aspects of this invention allow for real-time feature tracking ultrasound imaging during a medical procedure.
SUMMARY OF THE INVENTION
[0009] Various implementations of the invention provide techniques and supporting systems that facilitate real-time or near-real-time ultrasound tracking for the purpose of calculating changes in anatomical features during a medical procedure. While the methods are primarily described in terms of a radiotherapy fraction, other applications are contemplated, such as cryotherapy, brachytherapy, high-intensity focused ultrasound (HIFU), as well as imaging procedures such as computed tomography (CT), four-dimensional CT, planar x-ray, PET, MRI, and SPECT, or any other medical procedure where it is important to monitor anatomical features throughout the treatment.
[0010] Although primarily concerned with intrafractional motion tracking, in some cases correction for interfractional motion may also be implemented prior to the tracking process. In some cases, a hybrid technique of acquiring a temporally-spaced combination of three-dimensional ultrasound images and targeted subsets of two-dimensional ultrasound images may be used. The two-dimensional ultrasound images are used to increase the frequency of feature tracking to render the process as close to real-time as possible.
[0011] In a first aspect, a computer-implemented method for tracking an anatomical feature or features (e.g., an organ, tumor, tumor bed, gland, critical anatomical structure, or other lesion) within a patient undergoing a medical procedure such as radiotherapy, radiotherapy planning, image-guided surgery, or other treatment includes obtaining a three dimensional image of a region that includes the feature being treated and determining the location of the feature within the region. The three dimensional image is obtained at a first periodicity (e.g., every 30 seconds) as to reduce the processing and storage burdens as compared to higher frequencies. In between each three dimensional image, a series of temporally-displaced targeted subsets of ultrasound images focused on the region are obtained at a greater periodicity (e.g., every 0.1-3 seconds), and each is compared with the three dimensional image to determine if there has been any changes to the feature (e.g., movement, morphing). To reduce processing and memory requirements, the targeted subsets are typically of lower quality, resolution and/or represent a smaller area of the region than that of the three dimensional images, thereby allowing for more frequent imaging and comparisons. In some preferred embodiments the target subsets are planes of ultrasound data rather than a full reconstructed 3D volume.
[0012] In some cases, a determination is made as to whether the displacement exceeds a displacement threshold (such as an upper limit of spatial displacement of the feature of interest) and if so, an updated three dimensional image of the region of interest is obtained sooner than would be obtained according to the first periodicity. The updated three dimensional image maybe used for subsequent comparisons with the targeted set of ultrasound images. In addition (or alternatively) a determination is made as to whether the displacement exceeds a safety threshold and if so, the medical procedure is halted to allow for one or more adjustments to the patient's orientation with respect to a treatment device. In certain implementations, one or more treatment apparatus (e.g., a treatment couch on which the patient is supported and/or a multi-leaf collimator for administering radiation therapy) may be continuously adjusted while treatment is being delivered to compensate for the displacement.
[0013] In some embodiments, image parameters used in obtaining the targeted subset of ultrasound images are adjusted based on the displacement. The displacement threshold may be an upper limit on spatial displacement of the feature or exceeding some predefined change in size. The comparison may, in some cases, include comparing grey-scale values of subsequent images to determine the displacement or shift of the feature.
[0014] The targeted subset may be a series of two dimensional image slices of the feature, a combination of two or more tracking planes (such as two orthogonal planes), which may, in some cases, be reconstructed as a set of voxels intersecting the planes. The images may be used as obtained, or, in some cases segmented. The images may be obtained from various angles and directions aimed at the feature, including, for example transperineally in the case of a prostate gland. In certain implementations, the targeted subset may be three dimensional ultrasound datasets related to a limited region of interest, which may be determined on an adjusted sector size, an adjusted image depth and/or an adjusted ultrasound sector angle and in some cases have a reduced resolution.
[0015] The three dimensional ultrasound images may be obtained using a motorized probe, a bi-planar probe or a matrix probe, any of which may be internal or external to the patient. In some instances, the probe may have traceable markers attached to it and be calibrated to pixels within the images to facilitate spatial tracking over time with respect to a particular coordinate system.
[0016] The feature to be tracked can be the target lesion being treated, a subset of the lesion, another feature which is proximal to the lesion, a fiducial, or any other feature deemed to be of importance during the medical procedure. Features may be extracted from both full three-dimensional ultrasound images as well as the targeted subset of ultrasound images to obtain a representation of the feature's motion in time, using either segmentation or pattern recognition algorithms.
[0017] In another aspect, a system for tracking an anatomical feature within a patient undergoing a medical procedure includes a processor and a memory register. The processor is configured to locate the feature of interest within a series of three dimensional images and iteratively compare temporally displaced targeted subsets of ultrasound images obtained at a periodicity greater than the first periodicity with the three dimensional image. The processor then determines, based on each comparison, a displacement of the feature of interest. The register receives and stores the images.
[0018] In some versions, the processor determines if the displacement exceeds a displacement threshold (an upper limit of spatial displacement of the feature of interest, for example) and if so, provide instructions to obtain an updated three dimensional image of the region of interest sooner than would be obtained based on the first periodicity. The processor may also determine if the displacement exceeds a safety threshold. If so, the processor can provide instructions to halt the medical procedure, thereby allowing for adjustments to be made to the patient's orientation with respect to a treatment device and/or to the orientation of the treatment device itself prior to reinstating the procedure.
[0019] In some cases, the system also includes an ultrasound probe for providing the images to the register. The probe may be a two dimensional ultrasound probe rotatably mounted into a housing such that the probe can move according to at least one degree of freedom, either longitudinally, in a sweeping motion about an axis or rotating about an axis. A motor may provide movement to the probe, based, for example, on instructions from a controller to alter the position of the probe relative to the patient, the housing or both. The controller may also provide additional adjustments to one or more imaging parameters. Some embodiments may also provide a display and/or input devices, thus allowing an operator to view the images and interact with the system.
[0020] Changes identified in the feature may trigger a warning message (either visual, textual, audio or some combination thereof), warning the operator that the medical procedure should be modified. In other implementations, the changes may cause continuous or semi-continuous modifications to the treatment as it progresses.
BRIEF DESCRIPTION OF FIGURES
[0021] In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention.
[0022] FIG. 1 is a schematic diagram illustrating the use of a mechanical three-dimensional probe, referenced to a room coordinate system, for imaging a feature within a patient according to various embodiments of the invention.
[0023] FIG. 2 is a flow-chart illustrating a method for implementing a hybrid three-dimensional and two-dimensional temporal tracking strategy according to various embodiments of the invention.
[0024] FIG. 3 is a flow-chart illustrating a particular implementation of a hybrid three-dimensional and multiple two-dimensional plane temporal tracking strategy according to various embodiments of the invention.
[0025] FIG. 3A illustrates a particular implementation of a hybrid three-dimensional and multiple two-dimensional plane temporal tracking technique according to various embodiments of the invention.
[0026] FIG. 4 illustrates the use of tracking planes in the method of FIGS. 2 and 3 .
[0027] FIG. 5 is a flow-chart illustrating a particular implementation of a hybrid three-dimensional and limited ROI three-dimensional temporal tracking strategy according to various embodiments of the invention.
[0028] FIG. 6 illustrates a particular implementation of a hybrid three-dimensional and multiple two-dimensional plane temporal tracking in which the image extent encompassing the feature being treated is reduced according to various embodiments of the invention
[0029] FIG. 7 illustrates a system for tracking intrafractional motion during the course of radiotherapy according to various embodiments of the invention.
DETAILED DESCRIPTION
[0030] Throughout the following descriptions and examples, aspects and embodiments of the invention are described in the context of tracking intrafractional motion during the delivery of radiotherapy. However, it is to be understood that the present invention may be applied to tracking attributes of virtually any feature within or on a patient during any form of medical procedure requiring anatomical tracking, such as external beam and brachytherapy, cryotherapy, hyperthermia, high intensity focused ultrasound treatments (HIFU)) and/or various forms of imaging (e.g., CT, 4DCT, PET, US, SPECT, and MRI).
[0031] Referring to FIG. 1 , a motorized, mechanically sweeping three-dimensional ultrasound probe 100 , which is of particular use in this application, contains a two-dimensional probe inside of a housing, the two-dimensional probe being able to sweep at different angles within the housing, controlled by a motor. In certain applications, tracking markers 105 are affixed to the probe handle such that the position of the probe can be detected by a tracking system 110 . One such tracking device utilizes an infrared optical camera, which tracks infrared signals emitted from or reflected by the markers. The position and orientation of the probe housing can therefore be determined at all times, based on a relative coordinate system. In certain applications, the individual ultrasound pixels are referenced to a coordinate system useful for the medical procedure, which can for example be tied to room, a treatment device, an imaging device, or a patient.
[0032] Because the motorized sweeping probe is essentially a two-dimensional probe that moves according to a particular degree of freedom inside the housing, its position within the housing can be quantified in terms of a parameter X. The parameter X can be measured as an angle in the case of rotational sweep inside the housing, or as a distance in the case of a linear sweep. The parameter X can be controlled by a controller though an interface to the motor. For example, the controller may instruct the motor to move the two-dimensional probe to a particular location within the housing such that a two-dimensional frame can be acquired at a fixed position X. In other cases, the controller may instruct the motor to continuously move probe within the housing, facilitating the acquisition of a three-dimensional sweep by acquiring a series of temporally-displaced image frames while continuously changing X.
[0033] In some applications, pixels in a given two-dimensional frame at position X are known relative to a fixed room coordinate system. One method of attributing coordinates to the pixels is to use a calibration algorithm similar to those developed for freehand 3DUS imaging, but using a fixed X=X cal , which relates all pixels in a “calibration slice” to the probe markers and hence to the room coordinate system. Known geometry of the three-dimensional probe can then be used to relate this calibration to the slices with other X values.
[0034] Calibration may also be achieved by temporarily affixing the three-dimensional probe to a phantom having embedded geometrical features. In such cases, a CT scan of the probe and phantom assembly is acquired, and then a three-dimensional sweep is acquired with the probe still fixed relative to the phantom. The 3DUS images are aligned relative to the CT scan using software that allows rotations and translations of the images such that the geometrical features visible in the 3DUS images match those as seen on CT. In some cases, segmented features extracted from the CT may be used instead of the CT pixel values themselves. The markers affixed to the probe handle are also visible on CT, and thus a relationship between the 3DUS pixels and the markers can be quantified, thus allowing each 3DUS pixel to be known relative to the markers. The pixels can then be referred back to the room coordinate system using known techniques used in the art for freehand 3DUS imaging.
[0035] For intrafractional tracking of a structure or anatomical feature, the probe is placed on the patient 115 prior to treatment such that the target 120 is within the field of view of the probe. The technique may be used, for example, for transperineal imaging of the prostate, or imaging of a breast tumor. A full three-dimensional image of the target structure 120 and its surrounding anatomy is acquired by continuously varying X, during which the ultrasound images are acquired at a given frame-rate f. The frame-rate is primarily limited by ultrasound physics such as the time needed to send and receive a sound wave, but also may be limited by hardware and computer processing constraints. A typical frame-rate is on the order of 20 Hz. As described above, the pixels in each frame at a known X can be attributed to certain coordinates in the room coordinate system, and therefore the two-dimensional slices can be used to a “reconstructed” 3DUS volume in reference to the room coordinate system.
[0036] Prior to radiotherapy, the patient is typically placed on the treatment table according to skin markings. Correction for interfractional motion can then be performed by imaging of the target or a proximal feature and adjusting the patient's position relative to the room coordinate system either by moving the patient, the couch, or both. This corrects for daily setup errors as well as changes in the anatomy since the treatment planning phase, and can be done with any number of known IGRT techniques. In some cases, this process may be accomplished by acquiring a first three-dimensional sweep of the target structure with the mechanized probe. Typically, the patient couch is moved to correct for initial target misalignments, although other strategies can be used such as modifying the treatment plan. However, this initial interfractional correction does not account for motion during the treatment itself (intrafractional motion), as addressed below.
[0037] After initial patient setup, successive temporally-displaced three-dimensional sweeps of the target structure, or more generally of anatomical features related to or near the target structure or other area of interest, can be acquired using the mechanized probe. Displacement of the feature or features in each successive image relative to previous images can then be determined. In one method, a difference in the grayscale between the images is quantified, or, in other cases, a segmentation algorithm is used to recontour the features in each image and the displacement between successive segmentations is determined. One or more treatment parameters may then be modified as the feature changes location or form. These modifications can be, but are not limited to: warning the operator that the feature has moved outside a given tolerance and instructing her to halt treatment and reposition the patient; automatically halting the treatment beam by synchronizing with the linear accelerator if the feature moves past a given tolerance; correcting for the displacement by automatically adjusting the couch, and then turning on the beam again; iteratively adjusting the beam (for example, by moving the couch, the beam, or both) as the linear accelerator is turned off and on; and/or continuously changing the beam shapes or alignment in synchrony with newly updated feature positions. In some cases, no modification is instituted if the feature has not changed or the changes are within allowable tolerances.
[0038] Although successive acquisition of three-dimensional images may be useful, the images are not truly real-time because of the time delay inherent in the “sweep” process. More specifically, the sweeping technique includes varying X during the sweep to acquire enough frames for reconstruction without gaps between the frames, which is limited by the frame-rate of the ultrasound (which itself is limited by ultrasound physics), creating a full three-dimensional reconstruction of the two-dimensional slices into a full three-dimensional ultrasound volume, and calculation of a representation of the feature from the images.
[0039] Strategy 1: Hybrid three-dimensional and two-dimensional temporal tracking.
[0040] One approach to using ultrasound for real-time treatment monitoring uses targeted subsets of three-dimensional ultrasound images (“TUS”), and is illustrated in FIG. 2 . In step 200 , a full three-dimensional sweep of the patient's anatomy, including the feature to be tracked, is acquired by continuously (or in many small discrete steps) varying X to acquire a full set of two-dimensional slices. The two-dimensional slices are then reconstructed in the room coordinate system, using each tagged X-position of the slices as well as the tracking camera information and calibration information, to form a 3DUS image.
[0041] In step 205 , the three-dimensional feature is located in the 3DUS image. This feature is referred to herein as the three-dimensional feature, as it is determined from a three-dimensional image, as opposed to a feature in a two-dimensional slice image, which is referred to as a two-dimensional feature. The location can be determined manually, semi-automatically, or fully automatically. For example, a three-dimensional pattern recognition algorithm may be used, or in the case of imaging a prostate, the user can place one or more “hint points” (i.e., one point in the center or 4-8 points on the prostate edges), to initiate a segmentation algorithm which then determines the full prostate surface in three dimensions. Alternatively, a contour from a planning session can be superimposed onto the three-dimensional image as an initial guess, and potentially warped to better fit the edges in the current image.
[0042] In step 210 , the treatment is modified to account for the current position of the feature as found in step 205 . This can be accomplished, for example, by moving the couch to align the feature (either manually or automatically) if the feature does not significantly change volume or shape. The beam may be temporarily stopped in some cases to allow for the couch motion. Other strategies may include completely recalculating the treatment plan, or re-shaping the beam apertures to better target the feature.
[0043] In step 215 , the X-position of the motorized probe is moved to a fixed position such that the two-dimensional ultrasound slice is optimally aimed at the feature. For example, if the feature is an organ such as the prostate or a breast lumpectomy cavity, which has been segmented, the beam can be aimed at the center of the structure. The optimal slice can alternatively be selected based on feature discernibility statistics extracted from the three-dimensional image at step 205 . In step 220 , a two-dimensional ultrasound slice is acquired at this fixed X-position, which is targeted at the feature, and in step 225 the two-dimensional feature is located in this ultrasound slice. In step 230 , if size, shape and/or locational characteristics of the feature have not changed since step 205 , another two-dimensional acquisition and feature location is executed (step 235 ). The process is then repeated until changes in the two-dimensional feature are identified.
[0044] A change may include, for example, that the feature has moved outside of the two-dimensional plane, which would result in a significant change in the grayscale values in the region of interest surrounding the feature. The change may also be due to movement of the feature within the two-dimensional plane by an amount greater than a pre-determined threshold, or that the feature has changed shape greater than a predetermined threshold. For prostate imaging, the two-dimensional plane is typically aligned with the sagittal plane which can detect anterior/posterior and superior/inferior motions, which are the most common, with left-to-right motions being much less common. An acceptable threshold may be 2 mm, meaning so long as the prostate center moves by less than 2 mm, step 235 is continued. If the displacement is greater than 2 mm (or some other threshold), the process moves to step 240 . Another reason to transition to step 240 is if that the two-dimensional prostate area changes significantly from one frame to the next, which implies that the prostate has moved out-of-plane—either to the right or left. In some applications, the location, alignment and/or orientation of the probe may be altered by a robotic arm into which the probe is placed.
[0045] At step 240 , a new full 3DUS sweep is initiated, and the process is repeated. The entire flowchart loop is continued until the treatment is completed. Using this methodology, three-dimensional acquisition is triggered if motion is detected based on two-dimensional image acquisitions, which, due to the lower processing demands, allows for real-time monitoring. As such, a full three-dimensional adaptation of the treatment is triggered only if it appears that the feature has moved out of tolerance. In some embodiments, step 240 is initiated not only if the feature has likely moved out of tolerance, but also at regular temporal intervals (e.g., every fifteen seconds) as an extra check.
[0046] This approach may be used in applications when movement has a high likelihood to be in a particular two-dimensional plane chosen by the orientation of the motorized probe. In some variations, when this likelihood is high, modification of the treatment can be added as a step between 225 and 230 such that the two-dimensional tracking info is used to identify treatment modifications in real-time.
[0047] Strategy 2: Hybrid three-dimensional and multiple two-dimensional plane temporal tracking.
[0048] In some applications in which the motion is not likely to be primarily constrained to a particular two-dimensional plane, a hybrid of three-dimensional and multiple two-dimensional plane temporal tracking techniques may be used. Referring to FIG. 3 , steps 300 , 310 and 315 are the same as 200 , 210 and 215 of FIG. 2 , respectively. In step 320 , a full sweep is acquired by the motorized probe. In step 325 , instead of reconstructing the entire three-dimensional image set, only the pixels in two or more tracking planes, preferably being orthogonal or close to orthogonal to each other, are reconstructed. An example is shown in FIG. 4 , showing tracking planes 200 and 205 being used for reconstruction.
[0049] The planes are selected so as to intersect with the feature 120 . In the case of an organ such as the prostate, the planes preferably intersect through the center of the organ, which can be found from computing the centroid of the segmented structure. As used herein, “reconstructed ultrasound plane” refers to a reconstruction of a voxel set attached to a single plane, as opposed to a complete three-dimensional reconstruction that reconstructs the entire 3D voxel set. While limiting the information available to only certain planes, the computational requirements to produce only the reconstructed ultrasound plane(s) are significantly lower. As such, step 325 saves time and memory space, since it is much quicker and more efficient to reconstruct pixels in planes than an entire voxel space, as well as locate changes in features, thus reducing temporal intervals between successive localizations. In some cases, one of the tracking planes is not a reconstructed plane, but consists of the pixels from an actual two-dimensional ultrasound image from a fixed position (at one particular X location) of the motorized probe, as described above in reference to FIG. 2 .
[0050] In other applications, none of the tracking planes are reconstructed, but consist of pixels from multiple two-dimensional ultrasound images obtained from different positions of the motorized probe along the X plane. For example, as shown in FIG. 3A , three plane positions can be selected, at positions X 1 (in the center of the feature), X 2 (to the left of center but still imaging part of the feature) and X 3 , (to the right of center but still imaging part of the feature). The probe can then obtain images at each of these positions in rapid succession in any convenient order without need for reconstruction. The X positions relative to the center of the feature can be strategically determined based, for example, on knowledge of the three-dimensional surface of the feature.
[0051] Referring back to FIG. 3 , in step 330 , the three-dimensional feature is located in the tracking planes, creating a three-dimensional surface, that when intersected by a plane, produces a two-dimensional curve. In one method, the shape and volume of the three-dimensional feature, as found in the first iteration of step 310 , is assumed to remain constant. By determining where the two-dimensional curves generated by cutting through the tracking planes best fit the grayscale values yields the desired three-dimensional location of the surface, and thus displacement of the feature relative to its position at the previous point in time. “Best fit” can mean, for example, maximization of the sum of image gradients along the curves.
[0052] Finding the location of the three-dimensional feature from the tracking planes assumes that at least part of the feature is visible in at least two planes, and increasing the number of planes (e.g., from two to three, or even higher), increases the likelihood that the feature is visible. In some cases, the feature may move to a position where it is no longer visible, as determined at step 335 . This determination can be made based on a failure of the process at step 330 , for example. If, however, the feature remains visible in one or more of the planes, the treatment is modified to account for the new position (step 340 ) and acquisition of tracking plane data continues (step 345 ) to make further adjustments. The position of the tracking planes in 325 may be re-centered to account for the displaced feature found in 330 . In the case where feature is no longer in the planes, the full 3DUS volume is reconstructed (step 350 ). This allows for re-centering of the tracking planes for further iterations, and to ensure that the tracking planes intersect the feature being tracked. The process illustrated in FIG. 3 ends once the treatment is complete (step 355 ). In some variations, path 350 will be taken even if the feature is still intersected by the tracking planes, at fixed time intervals in order to gather full three-dimensional data at various points in time.
[0053] Using this approach, the full three-dimensional displacement can be calculated as long the tracking planes intersect with the feature, thus reducing the number of times the full three-dimensional image needs to be reconstructed. In contrast to the hybrid three-dimensional and two-dimensional temporal tracking approach, the use of two-dimensional planes allows much faster monitoring of the feature because it does not necessitate full sweeps on the structure, even if a full three-dimensional image is reconstructed any time there is a significant change in the feature.
[0054] Strategy 3: Hybrid three-dimensional and low-resolution three-dimensional temporal tracking.
[0055] In another approach, a series of alternating high (full three-dimensional) and low resolution (“targeted”), ultrasound sweeps are used to track the volume and followed with full volume reconstruction. Reducing the resolution allows for faster sweeps, but due to the limited frame-rate of the ultrasound, fewer two-dimensional slices are acquired for the reconstruction. For example, the high resolution three-dimensional images may be acquired at a periodicity of every thirty seconds, whereas the lower resolution images are obtained every 0.1-3 seconds. A new high-resolution image is captured for every period, unless the comparison between the high-resolution and low-resolution images indicated the violation of a displacement threshold, in which case a new high-resolution image is obtained sooner than would have been taken otherwise. In some cases, the displacement may be sufficient to halt treatment altogether and adjust the patient, the treatment device or both.
[0056] Strategy 4: Hybrid three-dimensional and limited ROI three-dimensional temporal tracking.
[0057] FIG. 5 illustrates an alternative approach. Steps 500 - 515 are the same as steps 200 - 215 of FIG. 2 , respectively. In step 520 , the region of interest (ROI) of the three-dimensional volume is reduced such that it encompasses only the feature plus a limited amount of surrounding voxels. This is accomplished by limiting the sector size of the two-dimensional ultrasound frames throughout the sweep, in some cases asymmetrically, as well as the depth of penetration. Referring to FIG. 6 as an example, the full sector size and depth, leading to image extent 600 , are reduced to form the image extent 605 which encompasses the feature 610 with a small amount of padding. Reducing sector size and/or depth increases the frame-rate, which allows for faster sweeping motion while still acquiring sufficient slices for high resolution three-dimensional image reconstruction. The range of X values for the sweeping motion can also be limited, which increases the three-dimensional image acquisition as well. Many more temporal three-dimensional images can be acquired, but due to the smaller region, the risk that the feature moves outside of the limited ROI increases.
[0058] Returning to FIG. 5 , the limited three-dimensional ROI is reconstructed (step 525 ), and due to the smaller number of voxels, the speed of the reconstruction process is increased and the memory requirements are reduced as compared to a full three-dimensional reconstruction. In step 530 , the location of the three-dimensional feature within the limited ROI is determined. In step 535 , if the feature has remained in the limited ROI, step 545 is executed, continuing the tracking of the feature within the limited ROI. The ROI can be re-modified in step 520 to account for any new positioning of the feature. If the feature is no longer within the limited ROI, or getting too close to a boundary, then step 550 allows for a full ROI reconstruction prior to limiting the ROI again for further tracking. In some cases, full ROI sweeps are also acquired at various time intervals. The loop ends when treatment is complete, as represented by step 555 .
[0059] Strategy 5: Hybrid three-dimensional and multiple two-dimensional plane temporal tracking with reduced sector size
[0060] In another approach, two tracking planes are used—the first plane is a pure two-dimensional ultrasound at a fixed X position of the motorized probe as described above (the X position can be adjusted to include the tracked feature as its position is updated), and the second plane is a reconstructed plane which is orthogonal or near-orthogonal to the first plane. The ultrasound data in the second plane is acquired with a very small sector size, ideally approaching zero, so that the sweep can be performed quickly. In some variations, the sector size is very small during most of the sweep, is rapidly increased as the sweep crosses through X of the pure ultrasound plane, then reduced quickly again to complete the acquisition of reconstructed plane.
[0061] Locating an anatomical feature according to one or more of the methods descried above can be performed by drawing a structure (either manually, semi-automatically, or automatically) in a first image. This first image can, for example, be an image from a previous planning session, a previous treatment session, or an image obtained for a first interfractional motion correction prior to tracking. In most applications of interest, the structure being tracked does not change shape while the patient is on the table. Thus, the original structure can be moved from image to image, keeping its shape intact, so that it best-fits each image. The amount the structure is moved within an image provides a distance the feature has travelled between each successive image. If image acquisition is fast enough, motion between successive images is small and easier to track. This applies to both two-dimensional contours in planes as well as three-dimensional contours.
[0062] Although the specific applications above utilize a mechanized three-dimensional probe, other types of three-dimensional probes can be used as well. For example, matrix probes, which consist of a two-dimensional surface of piezoelectric elements, can acquire full three-dimensional ultrasound datasets. Bi-planar probes, which can simultaneously acquire two perpendicular slices of two-dimensional ultrasound data, can also be used in some embodiments.
[0063] Referring to FIG. 7 , a system 700 for performing the techniques described above includes a register 705 or other volatile or non-volatile storage device that receives image data from the ultrasound imaging probe(s) 710 and/or 715 via a cord or wire, or in some embodiments via wireless communications. The system also includes a processor 720 that, based on the image data, uses the techniques described above to create three-dimensional, time-based images of the region of interest and determine if the feature being treated has moved and/or morphed such that the displacement or changes in shape or size require adjustments to image parameters used to capture subsequent images. The processor calculates any necessary adjustments and, in some cases, provides updated imaging parameters to a controller 730 . The controller 730 directs the probe(s) 710 and/or 715 to implement the adjustments either mechanically (e.g., by changing the physical location of the probe within its housing or implementing positional adjustments directly or using a brace, arm or other support device) or electronically (e.g., by altering the power delivered to the probes and/or frequency of the ultrasound energy). As such, the feature remains in the region being imaged throughout the entire imaging and treatment process.
[0064] In some embodiments, a display 735 and an associated user interface may also be included, thus allowing a user to view and manipulate the images and/or treatment parameters. The display 735 and user interface can be provided as one integral unit (as shown) or separate units and may also include one or more user input devices such as a keyboard and/or mouse. The display can be passive (e.g., a “dumb” CRT or LCD screen) or in some cases interactive, facilitating direct user interaction with the images and models through touch-screens (using, for example, the physician's finger as an input device) and/or various other input devices such as a stylus, light pen, or pointer. The display 735 and input devices may be in location different from that of the register 705 and/or processor 720 , thus allowing users to receive, view, and manipulate images in remote locations using, for example, wireless devices, handheld personal data assistants, notebook computers, among others.
[0065] In various embodiments the register and/or processor may be provided as either software, hardware, or some combination thereof. For example, the system may be implemented on one or more server-class computers, such as a PC having a CPU board containing one or more processors such as the Pentium or Celeron family of processors manufactured by Intel Corporation of Santa Clara, Calif., the 680x0 and POWER PC family of processors manufactured by Motorola Corporation of Schaumburg, Ill., and/or the ATHLON line of processors manufactured by Advanced Micro Devices, Inc., of Sunnyvale, Calif. The processor may also include a main memory unit for storing programs and/or data relating to the methods described above. The memory may include random access memory (RAM), read only memory (ROM), and/or FLASH memory residing on commonly available hardware such as one or more application specific integrated circuits (ASIC), field programmable gate arrays (FPGA), electrically erasable programmable read-only memories (EEPROM), programmable read-only memories (PROM), programmable logic devices (PLD), or read-only memory devices (ROM). In some embodiments, the programs may be provided using external RAM and/or ROM such as optical disks, magnetic disks, as well as other commonly storage devices.
[0066] For embodiments in which the invention is provided as a software program, the program may be written in any one of a number of high level languages such as FORTRAN, PASCAL, JAVA, C, C++, C#, LISP, PERL, BASIC or any suitable programming language. Additionally, the software can be implemented in an assembly language and/or machine language directed to the microprocessor resident on a target device.
[0067] It will therefore be seen that the foregoing represents an improved method and supporting system for tracking features over the course of a medical procedure. The terms and expressions employed herein are used as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed. Moreover, although the above-listed text and drawings contain titles headings, it is to be understood that these title and headings do not, and are not intended to limit the present invention, but rather, they serve merely as titles and headings of convenience. | Various implementations of the invention provide techniques and supporting systems that facilitate real-time or near-real-time ultrasound tracking for the purpose of calculating changes in anatomical features during a medical procedure. More specifically, anatomical features within a patient undergoing a medical procedure are tracked by obtaining temporally-distinct three dimensional ultrasound images that include the feature of interest and obtaining a targeted subset of ultrasound images focused on the feature. Based on the targeted subset of ultrasound images, a displacement of the feature is determined and image parameters used to obtain the targeted subset of ultrasound images are adjusted based on the displacement. This results in a time-based sequence of three dimensional images and targeted ultrasound images of the feature that identify changes in the position, size, location, and/or shape of the feature. | 6 |
CROSS REFERENCE
[0001] The present application is based on, and claims priority from, Chinese application number 201610596069.4, filed on Jul. 25, 2016, the disclosure of which is hereby incorporated by reference herein in its entirety.
TECHNICAL FIELD OF THE INVENTION
[0002] The present invention relates to the technical field of semiconductor devices, particularly to a super-junction schottky diode.
BACKGROUND OF THE INVENTION
[0003] Diodes are one of the most commonly used electronic devices. The types of traditional diodes are schottky diodes and PN junction diodes. PN junction diodes can withstand high reverse blocking voltage and has better stability. However, PN junction diodes have a larger forward voltage and a longer reverse recovery time. Schottky diodes are based on the principle of metal-semiconductor junction. Schottky diodes have a lower forward voltage and a faster reverse recovery since it has no minority carrier accumulation during the forward conduction. However, schottky diodes have a larger reverse leakage current and a poor temperature characteristic. There is a tradeoff between schottky diode's breakdown voltage and the forward voltage, which is called the “silicon limit”. In order to improve the breakdown voltage of a schottky diode, the thickness of drift region must be enhanced and the doping concentration of drift region must be reduced, which leads to an increase of forward conduction loss. Therefore, the main application field of schottky diode is for low or middle voltage applications.
[0004] In order to improve the schottky diode's breakdown voltage without increasing its forward voltage, the super-junction structure is introduced into the schottky diode's drift region. For example, Chinese patent application “A super-junction schottky semiconductor device and its preparation method” (application number: 201210141949.4) provided a schottky diode based on the charge balance principle. However, the schottky junctions existing in schottky diodes are located on the surface of the devices, so that the current capacity of the schottky diode is limited since the surface area is limited.
SUMMARY OF THE INVENTION
[0005] The present invention provides a novel super-junction schottky diode. The effective area of the schottky junction is increased by forming the schottky junction at the trench located in the body of the device. Therefore, the current capacity of the novel schottky diode can be greatly improved. In addition, a super-junction structure is used to improve the device's reverse breakdown voltage and reduce the device's reverse leakage current.
[0006] According to an aspect of the invention, there is provided a super-junction schottky diode including: a metallized cathode electrode 1 , a N+ substrate 2 (i.e., a heavily doped substrate of a conductivity type N), an N-type drift region 3 (i.e., a drift region of a conductivity type N), and a metalized anode electrode 9 . Said N-type drift region 3 includes a P-type buried layer 4 (i.e., a buried layer of a conductivity type P), a P-type column 5 (i.e., a column of a conductivity type P), a P+ heavily doped region 6 (i.e., a heavily doped region of a conductivity type P), a N-type lightly doped region 8 (i.e., a lightly doped region of conductivity type N), and a trench 7 . The P-type buried layer 4 is under the trench 7 , and the top surface of the P-type buried layer 4 contacts with the bottom surface of the trench 7 . The P-type column 5 is located between two adjacent trenches 7 . The P+ heavily doped region 6 is disposed above the P-type column 5 , and the bottom surface of the P+ heavily doped region 6 contacts the top surface of the P-type column 5 . The N-type lightly doped region 8 is located on the side of the trench 7 and on the top surface of the N-type drift region 3 . Said trench 7 is filled with metal, and the metal together with the N-type lightly doped region 8 form a schottky junction. The top surface of the N-type lightly doped region 8 is covered with metal that is the same as the metal in the trench 7 , and the metal together with the N-type lightly doped region 8 also form a schottky junction. The top surfaces of said metal and the P+ heavily doped region 6 contact the bottom surface of the metalized anode electrode 9 . The junction depth of said P-type buried layer 4 is the same as the that of the P-type column 5 .
[0007] Additionally, the bottom surface of said P-type buried layer 4 and P-type column 5 can contact the top surface of the N+ substrate 2 .
[0008] Furthermore, the P-type buried layer 4 can be replaced with the thick oxide layer 10 .
[0009] Some beneficial effects of the present invention are as follow. Compared to the existing super-junction schottky diode, the structure of this invention has a larger forward current, a smaller forward voltage, and a better reverse breakdown characteristic.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 shows a diagrammatic sectional view of a power device according to the Embodiment 1 of the present invention.
[0011] FIG. 2 shows a diagrammatic sectional view of a power device according to the Embodiment 2 of the present invention.
[0012] FIG. 3 shows a diagrammatic sectional view of a power device according, to the Embodiment 3 of the present invention.
[0013] FIG. 4 to FIG. 12 show diagrammatic sectional views of steps for fabricating the device in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0014] In the following detailed description, the features of the various exemplary embodiments may be understood in combination with the drawings.
Embodiment 1
[0015] As shown in FIG. 1 , the first embodiment of the present invention provides a super-junction schottky diode.
[0016] FIG. 1 illustrates a super-junction schottky diode in accordance with thee present invention. The super-junction schottky diode includes: a metallized cathode electrode 1 , a N+ substrate 2 , an N-type drift region 3 and a metalized anode electrode 9 . Said N-type drift region 3 includes a P-type buried layer 4 , a P-type column 5 , a P+ heavily doped region 6 , an N-type lightly doped region 8 and a trench 7 . The P-type buried layer 4 is under the trench 7 , and the top surface of the P-type buried layer 4 contacts with the bottom surface of the trench 7 . The P-type column 5 is located between two adjacent trenches 7 . The P+ heavily doped region 6 is disposed above the P-type column 5 and the bottom surface of the heavily doped region 6 contacts the top surface of the P-type column 5 . The N-type lightly doped region 8 is located on the side of the trench 7 and on the top surface of the N-type drift region 3 . Said trench 7 is filled with metal, and the metal together with the N-type lightly doped region 8 form a schottky junction. The top surface of the N-type lightly doped region 8 is covered with metal that is the same as the metal in the trench 7 and the metal together with the N-type lightly doped region 8 also form a schottky junction. The top surfaces of said metal and the P+ heavily doped region 6 contact the bottom surface of the metalized anode electrode 9 . The junction depth of said P-type buried layer 4 is the same as the that of the P-type column 5 .
[0017] The mechanism of the present super-junction schottky diode provided by embodiment 1 will be explained as follows.
[0018] During the forward conduction period, the metalized anode electrode 9 is applied with high potential and the metallized cathode electrode 1 is connected to a low potential (e.g., ground). The trench 7 is filled with metal, and the metal trench together with the N-type lightly doped region 8 form a schottky junction. Because the trench 7 is embedded in the body of the device, the trench's sidewall area is large and thus the effective area of the schottky junction is enlarged. Therefore, the current capability of this power diode can be improved. In addition, the forward conduct voltage drop can be decreased to reduce the forward conduction loss by increasing the doping concentration of the N-type drift region 3 since there is a super-junction structure in the N-type drift region 3 . The doping concentrations of the N-type lightly doped region 8 and the N-type drift region 3 can be designed independently. As a result, a lower turn-on voltage can be obtained by decreasing the doping concentration of the N-type lightly doped region 8 , and a lower forward conduction voltage can be achieved by increasing the doping concentration of the N-type drift region 3 .
[0019] During the reverse blocking period, the metalized anode electrode 9 is connected to a low potential and the metallized cathode electrode 1 is at a high potential. The P-type column 5 together with the N-type drift region 3 with a relatively high doping concentration can realize a charge compensation and generate a horizontal electric field. This horizontal electric field depletes the N-type drift region 3 and then the electrical characteristic of the N-type drift region 3 is the same as the one of the intrinsic semiconductors in the vertical direction. Therefore, this schottky diode can withstand higher reverse breakdown voltage, and the reverse leakage current is decreased. Additionally, the horizontal electric field will appear between the P-type buried layer 4 and the N-type drift region 3 . Therefore, the reverse breakdown voltage is increased and the reverse leakage current can be further reduced. What's more, since the P-type buried layer 4 is located at the bottom of the metal trench 7 , the reverse leakage current can be reduced.
[0020] In embodiment 1, the structure of the present invention can be produced by the following steps.
[0021] Step 1—monocrystalline silicon preparation and epitaxy: The N-type drift region 3 with a certain thickness and doping concentration is deposited on the N-type heavily doped monocrystalline silicon substrate 2 by vapor phase epitaxy (VPE) or other methods, as shown in FIG. 4 .
[0022] Step 2—etching trench: A hard mask 11 (such as silicon nitride) is deposited on the surface of the silicon wafer as a barrier layer for subsequent etching. Then the hard mask 11 is etched after the lithography and then the deep trench is etched by the shelter of hard mask 11 , as shown in FIG. 5 . The etching process can be reactive ion etching or plasma etching.
[0023] Step 3—P-type column epitaxy: The deep trench is filled with P-type silicon material by an epitaxy process. Subsequently, superfluous P-type silicon on the surface of the wafer is removed by chemico-mechanical polishing (CMP). Thus, the P-type column 5 is formed, as shown in FIG. 6 .
[0024] Step 4—etching trench again: Another hard mask 12 (such as silicon nitride) is deposited on the surface of the silicon wafer as a barrier layer for subsequent etching. Then the hard mask 12 is etched after the lithography and then the deep trench is etched by the shelter of hard mask 12 , as shown in FIG. 7 . The etching process can be reactive ion etching or plasma etching.
[0025] Step 5—implanting ion: As shown in FIG. 8 , P-type buried layer 4 is formed on the bottom of the trench by ion implantation with the shelter of hard mask 12 .
[0026] Step 6—implanting ion again: As shown in FIG. 9 , the hard mask 12 is removed before the ion implantation. A bevel ion implantation is adapted to implant P-type impurity ions. The N-type lightly doped region 8 is formed by impurity compensation of the implanted P-type impurities with the N-type drift region 3 .
[0027] Step 7—filling metal: As shown in FIG. 10 , the deep trench is filled with proper schottky metal (such as Platinum). The metal together with the N-type lightly doped region 8 form schottky junction.
[0028] Step 8—etching contact hole: As shown in FIG. 11 , the metal above the P-type column 5 is etched to produce a contact hole. The P-type heavily doped region 6 is formed by P-type ion implantation.
[0029] Step 9—depositing metalized electrode: As shown in FIG. 12 , metal is deposited. on the top surface of the device to form the anode, electrode 9 . The anode electrode 9 is contacted with the metal trench 7 and the P-type heavily doped region 6 . Then the back of wafer is thinned and the cathode electrode 1 is produced by metallization.
Embodiment 2
[0030] As shown in FIG. 2 , based on the embodiment 1, the P-type column 5 and the trench 7 are extended. The bottom surfaces of both P-type column 5 and trench 7 touch the substrate 2 . The beneficial effect of this embodiment is that the reverse breakdown voltage and leakage current of the device can be improved further.
Embodiment 3
[0031] As shown in FIG. 3 , based on the embodiment 1, the P-type buried layer 4 is replaced with the thick oxide layer 10 . The breakdown can he prevented to occur at the bottom of the trench 7 and thus the reverse breakdown voltage of the device can be unproved.
[0032] In addition, other semiconductor materials such as silicon carbide, gallium arsenide, indium phosphide and germanium silicon can be used to replace silicon in manufacturing. | The present invention relates to the field of semiconductor technology, particularly to a super-junction schottky diode. According to the present invention, the effective area of schottky junction is increased by forming the schottky junction in the trench located in the body of the device. Therefore, the current capacity of this novel schottky diode can be greatly improved. In addition, a super-junction structure is used to improve the device's reverse breakdown voltage and reduce the reverse leakage current. The super-junction schottky diode provided in the present invention can achieve a larger forward current, a lower on-resistance and a better reverse breakdown characteristic. | 7 |
BACKGROUND OF THE INVENTION
Honeycomb material is a familiar product. It consists of an array of hexagonal cells made of flat sheet material and nesting so that each of the six walls of one hexagon is shared with a wall of an adjacent hexagon. When a honeycomb is made of stiff material it is very strong in the direction perpendicular with the axes of the hexagonal cells. It is frequently bonded between flat sheets to make strong but lightweight panels to make walls, airplanes, boats and other structures where rigidity, strength and light weight are important. Honeycomb material is also made of resilient material and in such form it has been used as a cushion. For example, U.S. Pat. No. 532,429 issued to Rogers discloses such a honeycomb structure as an insole.
The use of a honeycomb structure as a cushion is desirable because buckling of the thin walls of the honeycomb absorbs a great deal of energy per unit of thickness of the cushion. However, the honeycomb structure is inherently stiff and using a honeycomb cushion within a shoe causes the shoe to be inflexible.
One way known to manufacture a honeycomb structure is to place a number of ribbons side by side and bond them together intermittently. Thus, if two strips are bonded along their length along a given distance and then unbonded three times that distance, and if the other side of each strip is similarly bonded but with the bonding appropriately offset, expanding the elongated strips thus bonded in a lateral direction creates a honeycomb structure. This method of manufacturing a honeycomb structure will be discussed in greater detail hereinafter.
The difference between a honeycomb structure made by partial bonding of adjacent strips and conventional honeycomb structures is that one-third of the parallel walls of each hexagon are double, that is, are formed from the portions of two adjacent ribbons that were bonded together.
As stated above, the honeycomb structure made from intermittently bonded strips is created by laterally expanding the adjacent strips. However, the strips may also be overexpanded so that the two sides of the hexagon forming the top and bottom point straighten to lie in the same plane, in which case the hexagons become deformed into rectangles where two opposite sides are twice as long as the other two opposite sides. Overexpanded strips are very flexible in one direction and quite stiff in the other. The short sides of the rectangles are difficult to buckle and they are short and of double thickness, both of which contribute to stiffness. The long sides of the rectangle of an overexpanded honeycomb are twice as long as two short sides and therefore buckle more easily and in addition they are single thickness which also causes them to buckle more easily.
SUMMARY OF THE INVENTION
This invention is a sole for a shoe that is lightweight, that absorbs energy, i.e., the force of a foot making impact with a surface, that is very flexible along the length of the foot so that it bends easily while walking or running and stiff from side to side of the foot to prevent lateral motion of the foot during walking or running and to absorb the energy of impact. The sole of this invention includes a pad made of any suitable material such as foam elastomer. The pad is supported by an overexpanded honeycomb structure that supports the pad with the parallel double walls running across the width of the sole and the parallel single walls running the length of the sole. In a preferred embodiment, the overexpanded honeycomb structure is fixed to the pad to retain its overexpanded position and another pad, or at least a flexible sheet is bonded to the opposite side of the honeycomb cells so that the honeycomb structure is contained between a top and a bottom sheet of material.
The honeycomb structure is made of resilient material such as rubber. In the context of this description, resilient material is material that is flexible and that restores itself to its original shape when deformed, as opposed to flexible material which may not be resilient. For example, paper is flexible while rubber is resilient The sole of this invention may be employed as a separate insole to be inserted in shoes before they are worn, it may be employed as an insole permanently made in a shoe, it may be employed as a midsole and it may even be used as an outsole. The sole of this invention is not limited to any type of shoe but has greatest utility in athletic shoes such as running shoes, court shoes, and cleated shoes used in various sports. The side-to-side stiffness of the sole of this invention is particularly adapted to resist, or even to correct lateral movement or thrusts of a foot within a shoe during running or when making rapid changes in direction as in a court game. In fact, having a sole where the thickness of the honeycomb structure varies across the width of the sole can provide additional support for specific foot weaknesses such as where a runner's ankle tends to buckle inwardly each time his or her heel strikes the ground. Such a condition may be corrected or at least mitigated by having deeper honeycomb structure on the inside of the sole whereby it will resist lateral thrusts of .PA the foot while still being extremely flexible in bending between the heel and the toe.
At least one pad of each sole must be of foamed elastomer or its equivalent. The pads both cushion the foot from the sharp edges of the honeycomb cells and contain the honeycomb in overexpanded position. The pads may be continuous or they may be perforate to provide ventilation beneath a user's foot.
The honeycomb structure is oriented so that the walls of each expanded honeycomb cell lie in a plane perpendicular to the plane of the pad.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of parallel ribbons bonded in order to make a product useful in the present invention.
FIG. 2 is a plan view of the structure of FIG. 1 expanded laterally to form a honeycomb.
FIG. 3 is a plan view of the structure of FIG. 1 that has been laterally overexpanded.
FIG. 4 illustrates an insole embodying this invention partly cut away.
FIG. 5 is a cross section of the insole illustrated in FIG. 4 taken along the line 5--5 of FIG. 4.
DETAILED DESCRIPTION OF THE INVENTION
An essential element of the present invention is an overexpanded honeycomb having parallel double walls extending in one direction. One manner of making such a honeycomb is to bond ribbons that are aligned in a parallel array with the bonding constituting one quarter of the areas of the ribbons. In FIG. 1 such a parallel array is illustrated. Ribbons 10, 11, 12, 13, 14, 15 and 16 are aligned not only to be parallel with one another but to have the plannar surfaces of the ribbons parallel to one another. Bonding is effected between ribbon 10 and ribbon 11 at positions 20, 22 and 25. The unbonded areas 21 and 23 are three times the length of the bonded areas 20, 22 and 25.
Ribbon 12 is then aligned parallel with ribbon 11 and bonded to it in the same manner except that the bonded areas bisect the unbonded areas between ribbon 10 and ribbon 11. Ribbon 13 is bonded to ribbon 12 in the same manner except the bonded areas between ribbon 12 and 13 coincide in position with the bonded areas 20, 22 and 25 between ribbon 10 and ribbon 11. The pattern is repeated for as many side-to-side ribbons as is required to make a honeycomb structure of the desired size. Bonding is usually effected with adhesive. In all figures, the bonded area is represented by short, horizontal lines between the ribbons to be bonded.
The structure illustrated in FIG. 1 may be expanded by holding ribbon 10 and moving ribbon 16 sideways and to the right, as illustrated in FIG. 1. Upon expanding the structure of FIG. 1 in such a manner, a structure such as illustrated in FIG. 2, is formed. This familiar, hexagonal, honeycomb structure is very rigid considering the amount of material employed and the ribbon-like nature of the material. When made of stiff plastic, impregnated paper, or narrow strips of metal, the structure is strong enough to form a very rigid panel. Even when made of resilient materials such as ribbons of rubber, the structure illustrated in FIG. 2 is much stiffer in all directions than the material from which it is made.
FIG. 3 illustrates the overexpanded honeycomb structure which is obtained by moving ribbon 16 as illustrated in FIG. 2 even farther to the right. The overexpanded structure in FIG. 3 is the maximum expanison that can be obtained without stretching any of the resilient ribbons. The hexagonal cells illustrated in FIG. 2 are expanded to rectangular cells in which two opposite walls are twice the length of the other two opposite walls. The overexpanded structure as illustrated in FIG. 3 has double walls for all of the vertically extending walls while all of the horizontally-extending walls are single walls. In addition, the double walls are short while the single walls are long. The double walls are accordingly much more rigid both because of their double structure and because of their ability to resist buckling because of their short length while the horizontal walls are very flexible because they are single walls and because their expanded length makes buckling relatively easy.
FIG. 4 illustrates an insole embodying this invention. The insole is generally designated 30 and it consists of an upper foam elastomer pad 31, a lower sheet 32 (illustrated in FIG. 5) that may be foam elastomer or may simply be sheet material. The pad 31 and sheet 32 are bonded together around the edges as at 35 illustrated in FIG. 5. The cutaway portion in FIG. 4 shows that between pads 31 and 32 is the overexpanded honeycomb structure as illustrated in FIG. 3 with double walls 34 running across the width of the insole while single walls 33 run the length of the insole. This is also illustrated in FIG. 5.
The insole constructed as illustrated in FIG. 4 is very flexible from front to back. In other words, one walking on the insole of this invention would meet substantially no resistance in bending the insole from front to back to accommodate to the normal flexing of the foot as one walks or runs. However, the insole is quite rigid from side to side and resists bending or sideways slumping. In addition, the cushioning effect of the insole, specifically its ability to resist vertical forces, is the same in the overexpanded condition shown in FIG. 3 as it is in the expanded position shown in FIG. 2 because the same number of walls of the same length and with the same resistance to crushing are involved whether the honeycomb structure is expanded or overexpanded.
It is preferred that the cushion 31 be perforated with small holes 36 in an array such that each cell in the overexpanded honeycomb is ventilated. The perforated pad provides air circulation through the insole and prevents the insole from cushioning by compressing air in individual sealed cells. The array of perforations illustrated in FIG. 4 is only partial to avoid obscuring other structural features by unnecessarily completing the repeating pattern of holes.
Although the sole of this invention has been described with reference to a separate insole, it is evident that a shoe, particularly an athletic shoe, may be constructed with a permanent insole, midsole or outersole of this structure. It is also evident that the depth of the honeycomb structure, i.e., how far the honeycomb structure would hold foam pad 31 from sheet 32, can be varied depending upon the amount of cushioning desired and can be varied from one position in a sole to another. Specifically, a sole can be constructed with deeper honeycomb in the heel portion than in the portion supporting the ball of the foot to cushion heel impact shocks to a greater extent than the less forceful shocks absorbed by the ball of the foot. | An sole having an upper elastomer foam pad supported by an overexpanded honeycomb structure, the overexpanded honeycomb structure made by intermittently bonding ribbons of elastomer and expanding them laterally to produce a honeycomb structure having rectangular cells with the longer opposite walls of the rectangle twice the length of the shorter opposite walls of the rectangle, with the shorter opposite walls of the rectangle being double walls, and with the shorter opposite walls of the rectangle elongated in the direction across the sole. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This disclosure claims the benefit of U.S. Provisional Patent Application Ser. No. 61/452,475, filed on Mar. 14, 2011, entitled “Wireless Location Assignment,” the disclosure thereof incorporated by reference herein in its entirety.
[0002] This disclosure is related to the following U.S. patent applications:
[0003] U.S. Provisional Patent Application No. 61/444,590, filed on Feb. 18, 2011, entitled “Dynamic Channel Allocation”;
[0004] U.S. Provisional Patent Application No. 61/451,310, filed on Mar. 10, 2011, entitled “Dynamic Channel Allocation”;
[0005] U.S. Provisional Patent Application Ser. No. 61/440,814, filed on Feb. 8, 2011, entitled “IEEE 802.11 af”;
[0006] U.S. Provisional Patent Application Ser. No. 61/443,185, filed on Feb. 15, 2011, entitled “IEEE 802.11 af”; and
[0007] U.S. Non-Provisional patent application Ser. No. 13/369,102, filed on Feb. 8, 2011, entitled “WLAN CHANNEL ALLOCATION”.
[0008] The disclosures of all of the above-referenced patent applications are hereby incorporated by reference herein in their entireties.
FIELD
[0009] The present disclosure relates generally to the field of wireless communications. More particularly, the present disclosure relates to the allocation of location-based spectrum for wireless communications.
BACKGROUND
[0010] Wireless spectrum has historically been allocated in a fixed manner. For example, a government agency may allocate a particular frequency band to a particular TV channel in a particular city while prohibiting others from using that band in that city. This fixed allocation typically persists until another allocation is made.
[0011] Now some wireless spectrum is being made available for wireless communications using temporary location-based allocations. That is, this spectrum will be assigned by request based on the location of the requesting wireless device. This type of spectrum is often referred to as “white space.” For example, the broadcast TV channels that became available with the switch from analog to digital TV broadcasting are often referred to as “TV white space.” TV white space offers much higher bandwidth than Wi-Fi, and is expected to support “smart appliances” and other smart devices that communicate over white space channels. For example, a user might employ white space channels to remotely monitor and control appliances such as TV sets, hot water heaters, and the like.
[0012] FIG. 1 illustrates a conventional white space allocation process. Referring to FIG. 1 , a wireless device 102 determines its location using GPS signals 104 , and then sends a request 106 for white space allocation to a spectrum allocation server 108 , for example over a wide-area network (WAN) 110 such as the Internet. Request 106 includes the location of wireless device 102 . At 112 , server 108 consults a spectrum allocation database 114 to obtain an available frequency band (also referred to herein as a “channel”) based on the location of wireless device 102 . At 116 server 108 allocates the white space channel to wireless device 102 . Wireless device 102 can then communicate wirelessly over the allocated white space channel at 118 .
[0013] In the conventional location-based wireless spectrum allocation of FIG. 1 , wireless device 102 must determine its location. FCC regulations for television white space mandate that Mode II devices have geolocation capabilities such as GPS receivers for this purpose. However, not all devices that could utilize white space will have such geolocation capabilities. It may be too expensive to place GPS receivers in cost-sensitive consumer devices that are not mobile. For example, a television set is stationary and would not normally be built with GPS facilities. Adding a GPS receiver to a television set is too expensive just to enable white space usage. In addition, an indoor device such as a television set may be shielded from GPS satellites, and so the television set would be unable to obtain its location.
[0014] Alternatively, FCC regulations require fixed devices be “professionally installed” where a licensed installer configures the location in the wireless device 102 . However, this method is very expensive, and does not allow any movement of the wireless device, even from one room to another.
SUMMARY
[0015] In general, in one aspect, an embodiment features an apparatus comprising: a first transceiver, wherein the first transceiver includes a receiver configured to receive a first message from a first device, wherein the first message includes a location of the first device, and a transmitter configured to transmit a second message, wherein the second message includes the location of the first device, and a request for a frequency allocation based on the location of the first device; wherein the receiver is further configured to receive a third message, wherein the third message includes the frequency allocation; and a second transceiver configured to wirelessly communicate on a frequency band indicated by the frequency allocation.
[0016] In general, in one aspect, an embodiment features computer-readable media embodying instructions executable by a computer to perform functions comprising: obtaining a location of a device from a first message received by a first transceiver of the device; causing the first transceiver to transmit a second message, wherein the second message includes an indication of the location of the device, and a request for a frequency allocation based on the location of the device; obtaining the frequency allocation from a third message received by the first transceiver; and configuring a second transceiver to wirelessly communicate on a frequency band indicated by the frequency allocation.
[0017] In general, in one aspect, an embodiment features computer-readable media embodying instructions executable by a computer to perform functions comprising: determining a location of the computer; causing a transceiver to wirelessly transmit a first message, wherein the first message includes an indication of the location of the computer, wherein causing the transceiver to wirelessly transmit the first message includes causing the transceiver to wirelessly transmit the first message in response to a second message received by the transceiver, wherein the second message includes a request for the location of the computer.
[0018] The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims.
DESCRIPTION OF DRAWINGS
[0019] The leading digit(s) of each reference numeral used in this specification indicates the number of the drawing in which the reference numeral first appears.
[0020] FIG. 1 illustrates a conventional white space allocation process according to the prior art;
[0021] FIG. 2 illustrates a white space allocation system according to the principles of the present disclosure;
[0022] FIG. 3 illustrates a digital television according to the principles of the present disclosure;
[0023] FIG. 4 illustrates a smartphone according to the principles of the present disclosure;
[0024] FIG. 5 illustrates a spectrum allocation process according to the principles of the present disclosure; and
[0025] FIG. 6 illustrates a white space allocation system including an access point according to the principles of the present disclosure.
DETAILED DESCRIPTION
[0026] Embodiments of the present disclosure provide assisted location-based wireless spectrum allocation for wireless devices that do not have geolocation capabilities. For clarity this spectrum is referred to herein as “white space,” and the wireless device obtaining a channel allocation in the white space and communicating over the allocated white space channel is referred to as a “white space device.” However, the disclosed embodiments apply to any wireless spectrum allocated based of the location of the wireless device.
[0027] As used herein, the term “server” generally refer to an electronic device or mechanism, and the terms “message,” “request,” “response,” and the like generally refer to an electronic signal representing a digital message. As used herein, the term “mechanism” refers to hardware, software, or any combination thereof. These terms are used to simplify the description that follows. The servers and mechanisms described herein can be implemented on any standard general-purpose computer, or can be implemented as specialized devices. Furthermore, while some embodiments are described with reference to a client-server paradigm, other embodiments employ other paradigms, such as peer-to-peer paradigms and the like.
[0028] In the disclosed embodiments, one or more “assistant” devices having geolocation capabilities provides location information to the white space device. The white space device then uses this location information to obtain a white space channel allocation. Once the white space device is allocated a white space channel, the white space device can communicate wirelessly over that channel.
[0029] FIG. 2 shows an embodiment where the white space device is a digital television set and the assistant device is a smartphone. Although in the described embodiments the elements of FIG. 2 are presented in one arrangement, other embodiments may feature other arrangements. For example, the elements of FIG. 2 can be implemented in hardware, software, or combinations thereof.
[0030] Referring to FIG. 2 , digital television set (DTV) 204 has no geolocation capability, but has the capability to communicate wirelessly over white space channels with other nearby white space devices 270 . Smartphone 202 has geolocation capabilities, for example using GPS signals 104 . Smartphone 202 can communicate its location to DTV 204 , for example using a wireless local-area network (WLAN) 206 . After obtaining the location, DTV 204 can operate as an FCC Mode II device. That is, DTV 204 can obtain a white space channel allocation from a spectrum allocation server 108 and a spectrum allocation database 114 over a wide-area network (WAN) 110 according to conventional techniques such as those described above with reference to FIG. 1 .
[0031] FIG. 3 shows detail of DTV 204 according to one embodiment. Although in the described embodiments the elements of FIG. 3 are presented in one arrangement, other embodiments may feature other arrangements. For example, the elements of FIG. 3 can be implemented in hardware, software, or combinations thereof.
[0032] DTV 204 includes a transceiver 306 , a motion detector 308 , an authentication circuit 310 , a cryptographic circuit 312 , and a signal strength circuit 316 . Authentication circuit 310 and cryptographic circuit 312 can be implemented as separate circuits or as one or more processors. Signal strength circuit 316 can be implemented as part of transceiver 306 . DTV 204 also includes other circuits and modules 318 such as a digital television receiver, display, speakers, remote control interface, a processor, and the like.
[0033] Transceiver 306 includes a network transceiver 320 to support wireless and/or wired network communications such as Internet Protocol communications and a white space transceiver 322 to support wireless communications over white space channels. Network transceiver 320 includes a network transmitter 324 and a network receiver 326 . White space transceiver 322 includes a white space transmitter 330 and a white space receiver 332 . Transceivers 320 and 322 can be implemented together, separately, or with one or more circuits in common.
[0034] FIG. 4 shows detail of smartphone 202 according to one embodiment. Although in the described embodiments the elements of FIG. 4 are presented in one arrangement, other embodiments may feature other arrangements. For example, the elements of FIG. 4 can be implemented in hardware, software, or combinations thereof.
[0035] Smartphone 202 includes a GPS receiver 440 that provides geolocation capabilities based on received GPS signals 438 . Smartphone 202 also includes a Wi-Fi transceiver 442 for wireless network communications. Wi-Fi transceiver 442 includes a Wi-Fi transmitter 444 and a Wi-Fi receiver 446 . Smartphone 202 also includes an accelerometer 448 , a certification circuit 450 , and a cryptographic circuit 452 . Certification circuit 450 and cryptographic circuit 452 can be implemented as separate circuits or as one or more processors. Smartphone 202 also includes other circuits and modules 454 such as a wireless phone transceiver for communications over a wireless phone network, a display, a speaker, a control interface, a processor, and the like.
[0036] FIG. 5 shows a process 500 for the embodiments of FIGS. 2-4 according to one embodiment. Although in the described embodiments the elements of process 500 are presented in one arrangement, other embodiments may feature other arrangements. For example, in various embodiments, some or all of the elements of process 500 can be executed in a different order, concurrently, and the like. Also some elements of process 500 may not be performed, and may not be executed immediately after each other.
[0037] Process 500 generally begins with smartphone 202 obtaining its location at 502 . In the embodiment of FIG. 2 , smartphone 202 includes a GPS receiver 440 to determine the location of smartphone 202 based on GPS signals 104 received by smartphone 202 . In order to use GPS positioning, signals 104 must not be blocked or overly attenuated. In general, this means that the position must be determined outside of any building in which DTV 204 is located. For small buildings, the difference between the locations of smartphone 202 and DTV 204 may be insignificant for the purposes of obtaining a white space channel allocation. However, in other cases, for example when DTV 204 is located deep inside a large building, the location difference may have to be accounted for. In such situations, smartphone 202 can include an accelerometer 448 or the like to measure the distance and direction between a previously-determined location of smartphone 202 and the location of DTV 204 . From this information, smartphone 202 can provide a good estimate of the location of DTV 204 .
[0038] Smartphone 202 then provides location information to DTV 204 . In the embodiment of FIG. 5 , this process is initiated by a request from DTV 204 . However, other methods can be used. In some embodiments, smartphone 202 executes an application that provides the location information to DTV 204 . For example, the application can be provided by the manufacturer of DTV 204 .
[0039] Referring again to FIG. 5 , at 504 smartphone 202 receives a message from DTV 204 that requests the location of DTV 204 . In the embodiment of FIG. 2 , this request is sent by Wi-Fi from network transmitter 324 of DTV 204 to Wi-Fi receiver 446 of smartphone 202 . However, other methods of communication can be used.
[0040] In response to the request, smartphone 202 sends a message to DTV 204 at 510 that includes the location information. In the described embodiments, the location information includes the latitude and longitude of smartphone 202 . However, the location information can take other forms, and can include other parameters such as altitude and the like.
[0041] To prevent fraud in obtaining white space channel allocations, the message can be cryptographically bound. Therefore at 506 certification circuit 450 of smartphone 202 certifies the message before transmission. That is, certification circuit 450 provides proof of the identity of smartphone 202 or the user of smartphone 202 . For example, certification circuit 450 digitally signs the message. However, other certification methods can be used instead. As a further security measure, cryptographic circuit 452 of smartphone 202 encrypts the message at 508 before transmission. Various embodiments can employ symmetric key cryptography, asymmetric key cryptography, and the like.
[0042] The message containing the location information is sent by Wi-Fi from Wi-Fi transmitter 444 of smartphone 202 to network receiver 326 of DTV 204 at 510 . However, other methods of communication can be used. Cryptographic circuit 312 of DTV 204 decrypts the message at 512 . Authentication circuit 310 of DTV 204 authenticates the message at 514 . For example, authentication circuit 310 verifies a digital signature used to sign the message. At this point DTV 204 has the location information for smartphone 202 .
[0043] In some cases, DTV 204 receives responses from multiple devices at 510 . For example, if multiple smartphones 202 are within Wi-Fi range of DTV 204 , then two or more of the smartphones 202 may respond. In some embodiments, DTV 204 selects one of the smartphones 202 to obtain the most accurate position estimate. In one such embodiment, DTV 204 employs signal strength circuit 316 to select the strongest signal, which should originate from the nearest smartphone 202 . DTV 204 then takes the location information provided in the selected signal. In other embodiments, DTV 204 combines location information from two or more smartphones 202 to obtain a location estimate for DTV 204 .
[0044] DTV 204 then sends a request for a frequency allocation to spectrum allocation server 108 at 516 . The request includes the location of smartphone 202 . In particular, network transmitter 324 of DTV 204 sends the request to spectrum allocation server 108 over network 110 .
[0045] At 518 spectrum allocation server 108 selects a white space channel by indexing spectrum allocation database 114 using the location of smartphone 202 . For example, spectrum allocation database 114 can list the current frequency allocations at the location of smartphone 202 , and spectrum allocation server 108 chooses a channel that is not currently allocated for that location.
[0046] At 520 spectrum allocation server 108 sends a message to DTV 204 . Network receiver 326 of DTV 204 receives the message. The message indicates the white space channel allocated to DTV 204 by spectrum allocation server 108 . In some embodiments, for further security, communications between DTV 204 and spectrum allocation server 108 are certified/authenticated and/or encrypted.
[0047] At 522 DTV 204 configures white space transceiver 322 to use the white space channel allocated to DTV 204 by spectrum allocation server 108 . At 524 white space transceiver 322 wirelessly communicates with other white space devices 270 using wireless white space signals 118 over the white space channel allocated to DTV 204 by spectrum allocation server 108 .
[0048] The white space channel allocation is valid only for the location provided by DTV 204 in the spectrum allocation request. So if moved from that location, DTV 204 is no longer allowed to communicate over that white space channel. To enforce this restriction, in the embodiment of FIG. 4 , DTV 204 includes a motion detector 308 . At 526 motion detector 308 indicates that DTV 204 has moved. At 528 , in response to the motion detection, white space transceiver 322 , including white space receiver 332 and white space transmitter 330 , ceases wirelessly communicating on the allocated white space channel. When motion detector 308 indicates that DTV 204 is once again stationary, process 500 can begin again to obtain a new white space channel allocation for DTV 204 . DTV 204 can also consider the length of time during which motion is detected. For example if someone bumped into DTV 204 or moved DTV 204 from one room to another, the motion would not last long and so should not trigger white space channel allocation process 500 again.
[0049] In the embodiment of FIG. 2 , the assistant device is a smartphone 202 . In other embodiments, other sorts of devices act as assistant devices to provide location information to white space devices. FIG. 6 shows an embodiment where the assistant device is an access point 602 in a wireless local-area network (WLAN) 606 . Although in the described embodiments the elements of FIG. 6 are presented in one arrangement, other embodiments may feature other arrangements. For example, the elements of FIG. 6 can be implemented in hardware, software, or combinations thereof.
[0050] Access point 602 can learn its location from an access point database 614 that lists locations of access points. Such access point databases 614 have been compiled and are currently in use, for example by Internet service providers. Access point 602 can then provide the location information to nearby white space devices such as DTV 204 . A computer 612 can perform this function instead, or in conjunction with access point 602 .
[0051] In the embodiment of FIG. 2 , the white space device is a DTV 204 . However, it will be appreciated that the white space device can be any sort of device that is capable of white space communications. Such devices can include other electronic devices, appliances, thermostats, automobiles, and so on.
[0052] In the embodiment of FIG. 2 , smartphone 202 employs GPS signals to determine its location. However, assistant devices can use any method to determine their location. For example, other satellite positioning systems are planned. Terrestrial transmitters can be used instead or in combination with such satellite systems.
[0053] Various embodiments of the present disclosure can be implemented in digital electronic circuitry, or in computer hardware, firmware, software, or in combinations thereof. Embodiments of the present disclosure can be implemented in a computer program product tangibly embodied in a computer-readable storage device for execution by a programmable processor. The described processes can be performed by a programmable processor executing a program of instructions to perform functions by operating on input data and generating output. Embodiments of the present disclosure can be implemented in one or more computer programs that are executable on a programmable system including at least one programmable processor coupled to receive data and instructions from, and to transmit data and instructions to, a data storage system, at least one input device, and at least one output device. Each computer program can be implemented in a high-level procedural or object-oriented programming language, or in assembly or machine language if desired; and in any case, the language can be a compiled or interpreted language. Suitable processors include, by way of example, both general and special purpose microprocessors. Generally, processors receive instructions and data from a read-only memory and/or a random access memory. Generally, a computer includes one or more mass storage devices for storing data files. Such devices include magnetic disks, such as internal hard disks and removable disks, magneto-optical disks; optical disks, and solid-state disks. Storage devices suitable for tangibly embodying computer program instructions and data include all forms of non-volatile memory, including by way of example semiconductor memory devices, such as EPROM, EEPROM, and flash memory devices; magnetic disks such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM disks. Any of the foregoing can be supplemented by, or incorporated in, ASICs (application-specific integrated circuits).
[0054] A number of implementations have been described. Nevertheless, various modifications may be made without departing from the scope of the disclosure. Accordingly, other implementations are within the scope of the following claims. | Apparatus having corresponding computer-readable media comprise: a first transceiver, wherein the first transceiver includes a receiver configured to receive a first message from a first device, wherein the first message includes a location of the first device, and a transmitter configured to transmit a second message, wherein the second message includes the location of the first device, and a request for a frequency allocation based on the location of the first device; wherein the receiver is further configured to receive a third message, wherein the third message includes the frequency allocation; and a second transceiver configured to wirelessly communicate on a frequency band indicated by the frequency allocation. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority 35 U.S.C. §120 as a continuation of U.S. Non-Provisional Application Ser. No. 12/472,829, filed May 27, 2009, which in turn claims priority under 35 U.S.C. §119(e) from U.S. Provisional Patent Application Ser. No. 61/056,187, filed on May 27, 2008, the entirety of which are each expressly incorporated by reference herein.
FIELD OF THE INVENTION
[0002] This invention relates to targets for practicing the firing of a projectile, and more specifically to targets that provide a more realistic shooting profile to an individual.
BACKGROUND OF THE INVENTION
[0003] With regard to targets, there are many different types of targets that have been previously developed to give individuals the ability to practice effectively striking a target with a projectile, such as a bullet or an arrow. These targets come in various shapes and sizes, with many targets having the shape of the different animals that are going to be hunted by the archer. These targets can also be configured to move in the nature of the actual animal being hunted, and can be formed from a number of different materials to give a more realistic structure to the actual target, which in each case presents a more realistic target to the hunter.
[0004] However, these prior art targets, while providing a more than adequate structure for approximating the size and shape of the particular animal, have a significant shortcoming concerning the position or profile they present when used as a target. In particular, the prior art targets are each mounted to a structure that holds the target in a generally upright position, such that the target is perpendicular to the ground. This position is acceptable when the hunter expects to be shooting only horizontally at the target. However, in many situations the hunter is located in an elevated position with regard to the animal, such as in a tree stand, so the animal does not present a full profile to the hunter. But when practicing, often times the individual is not in the elevated position and is shooting horizontally at the target. Thus, a target mounted to only present a horizontal full side profile to the hunter does not provide an accurate representation of the target at which the hunter is shooting when in an elevated position.
[0005] Therefore, it is desirable to develop a target that is mounted to a support in a manner that enables the target to be moved into different angular positions with regard to the support. By moving to these positions, the target can present a realistic profile to a hunter shooting horizontally at the target to approximate the animal profile seen when shooting from an elevated location.
SUMMARY OF THE INVENTION
[0006] According to one aspect of the present invention, a target is provided that includes a target body mounted to a base structure. The target body can be formed in a conventional manner and/or of conventional materials, and can have any desired shape. The target body is secured to an upright member that extends outwardly from the target body. Opposite the target body, the upright member is pivotally secured to a support member that can rest on the ground or other surface to support the target body. Due to the pivotal connection of the upright member to the support member, the target body can be angularly adjusted relative to the support member to provide a reduced profile that is more representative of the actual animal profile seen by a hunter located in an elevated hunting position, such as in a tree stand.
[0007] According to still another aspect of the present invention, the support member and the upright member include indicia illustrating the proper position of the upright member relative to the support member to provide an animal profile for a specified elevation and distance for the individual from the animal.
[0008] Numerous other aspects, features and advantages of the invention will be made apparent from the following detailed description taken together with the drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The drawing figures illustrate the best mode currently contemplated of performing the present invention.
[0010] In the drawings:
[0011] FIG. 1 is an isometric view of a target constructed according to the present invention in an upright position;
[0012] FIG. 2 is a rear plan view of the body of the target of FIG. 1 in an angled position with regard to the support member;
[0013] FIG. 3 is a partially broken away cross-sectional view along line 3 - 3 of FIG. 2 ; and
[0014] FIG. 4 is a partially broken away cross-sectional view similar to FIG. 3 of a second embodiment of the target of FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
[0015] With reference now to the drawing figures in which like reference numerals designate like parts throughout the disclosure, a target constructed according to the present invention is illustrated generally at 10 in FIG. 1 . The target 10 includes a body portion 12 secured to a support means 13 . The body portion 12 can take the shape of any desired animal or portion thereof to be hunted by an individual, or any other desired shape. The body portion 12 can also be formed of any suitable material, such as various molded foam materials, ballistics gels, or plastic materials, among others. The body portion 12 can also have any desired internal structure (not shown) to support the material forming the body portion 12 , such as a wire mesh or tubular members disposed within the body portion 12 , or any other internal or external features designed to assist the individual utilizing the target 10 , e.g., in determining the accuracy or other parameters of the shots being fired at the target 10 or moving the target 10 .
[0016] The body portion 12 is affixed to one end of an upright member 14 of the support means 13 , such as by connecting the upright member 14 to the internal structure of the body portion 12 , or molding the material forming the body portion 12 around one end of the upright member 14 . Additionally, the internal structure of the body portion 12 can extend outwardly from the body portion 12 to be engaged with the upright member 14 in a manner that allows the body portion 12 to be rotated along a generally vertical axis about the upright member 14 . In a preferred embodiment, the internal structure includes a portion 15 insertable onto or into the upright member 14 and rotatable with respect thereto.
[0017] To enable the upright member 14 to support the body portion 12 , the upright member 14 is preferably formed of a generally rigid material, such as a metal or hard plastic, that can have any desired shape sufficient to engage and securely hold the body portion 12 , and also sufficient to withstand a strike from an arrow (not shown) or other projectile that may strike the upright member 14 .
[0018] The upright portion 14 , in a preferred embodiment, is formed from a vertical member 16 that is affixed to the body portion 12 , and a horizontal member 18 secured to the vertical member 16 , such as by welding, to form a T-shaped upright member 14 . More preferably, the vertical member 16 and the horizontal member 18 are each formed from a tubular structure, most preferably having a circular cross-section, and formed from a metal, such as aluminum or steel.
[0019] Opposite the body portion 12 , the upright member 14 is secured to a support member 20 . The support member 20 includes a base member 22 and a pair of opposed sockets 24 spaced from one another and secured to the base member 22 , such as by welding or by using a suitable fastener or adhesive. Preferably the sockets 24 are disposed at or adjacent to the opposite ends of the base member 22 , which is formed of a metal, such that the sockets 24 , also preferably formed of a metal, can be welded thereto. Alternatively, the base member 22 and the sockets 24 can be formed from materials such as various metals or plastics that enable the base member 22 and sockets 24 to be integrally formed with one another in a suitable molding process.
[0020] The base member 22 can be formed in any suitable manner to provide a point of attachment for the upright member 14 and the body portion 12 to a stable base to maintain the target 10 in a desired position when in use. The base member 22 can be formed to function as the stable base itself, or can be configured to be secured to any other structure or surface, such as by welding or using any suitable fasteners, including stakes 100 that can be driven through openings 25 in the base member 22 to affix the base member 22 to the ground.
[0021] The sockets 24 are formed to have an interior cross-section that is complementary to the shape of the horizontal member 18 of the upright member 14 , such that the ends of the horizontal member 14 can be inserted into the sockets 24 and rotated therein along a generally horizontal axis. Within each of the sockets 24 is disposed a suitable frictional member 200 that operates to restrict the rotation of the horizontal member 18 with respect to each of the sockets 24 such that the horizontal portion 18 , and consequently the body portion 12 secured thereto, can be maintained in the desired angular position to present a profile of the body portion 12 corresponding to the likely elevation and distance between the hunter and the animal. The frictional member 200 is formed o any suitable material that can securely frictionally engage the horizontal member 18 to hold the horizontal member 18 stationary within the socket 24 , while also allowing the member 18 to be rotated when a sufficient force is applied to the member 18 .
[0022] Additionally, to assist the frictional member 200 in holding the body portion 12 in the desired angular position relative to the support member 20 , a suitable locking device 400 is disposed on one the upright member 14 or the support member 20 and is capable of securely, but releasably, engaging the other of the upright member 14 or the support member 20 to maintain the position of the members 14 and 20 relative to one another when struck by a projectile. Examples of these types of devices include ratchet mechanisms, locking pins, which can be spring-biased, locking clips and tabs, among other suitable devices. In an alternative embodiment, the member 200 can alternatively be formed to be a bearing member, with the locking device 400 solely providing the function of holding the upright member 14 and support member 20 stationary with regard to one another.
[0023] In another embodiment of the invention, as best shown in FIG. 4 , the horizontal portion 18 of the upright member 14 is connected to the support member 20 by being inserted within the socket 24 that is formed of a tubular member that is secured to an upright bracket 500 connected to the base member 22 generally opposite the socket 24 . The upright bracket 500 is affixed to the socket 24 and the base member 22 in any suitable manner, such as by using mechanical fasteners or by welding or adhering the pieces together. In a preferred structure, the upright bracket 500 is made of a metal that enables the bracket 500 to be welded to the socket 24 and base member 22 .
[0024] To hold the upright member 14 at the desired angle with respect to the socket 24 , a locking device 400 in the form of a hose clamp 402 is secured around the horizontal portion 18 of the upright member 14 and connected to the socket 24 in a suitable manner. The clamp 402 is formed with a band 404 of a suitable material disposed around the horizontal member 18 and connected at each end to a securing mechanism 406 . The mechanism 406 has a handle 408 that allows the device 406 to be tightened and loosened, in order to tighten and loosen the band 404 around the horizontal member 18 in a known manner, thereby enabling or disabling the ability of the horizontal member 18 to rotate with respect to the socket 24 .
[0025] To allow the hunter to put the body portion 12 in the desired position, the sockets 24 and/or the horizontal portion 18 can have indicia 300 printed thereon which provides the hunter with the proper position of the horizontal portion 18 for a shot at a specified height for the hunter and a specified distance between the animal and the hunter. In addition, due to the ability of the body portion 12 to rotate along the longitudinal axis of the vertical member 16 , the body portion 12 can also be positioned to allow the hunter to simulate a shot of the animal walking directly towards the hunter, directly away from the hunter, or at any angle therebetween.
[0026] Various alternatives are contemplated as being within the scope of the following claims, which particularly point out and distinctly claim the subject matter regarded as the present invention. | The present invention is an adjustable projectile target that includes a support structure that can hold a body portion of the target at various angular positions with regard to the support structure. The support structure allows the body portion to be rotated along both a vertical and a horizontal axis to provide a variety of target profiles for the body portion to simulate for the individual shots taken from various elevations and distances from the target animal. | 5 |
BACKGROUND OF THE INVENTION
A storage area network (SAN) can be defined as a dedicated fibre channel network of interconnected storage devices and servers (more generally known as nodes), which offers any-to-any communication, i.e., any two nodes can communicate with each other. Accordingly, communication is possible between any storage device and any server, thus allowing multiple servers to access the same storage device independently. Furthermore, some storage devices may directly communicate with each other, enabling back up and replication of stored data to take place without impacting server performance.
A fibre channel network is a scalable data network for connecting heterogeneous systems (e.g., super computers, mainframes, and work stations) and peripherals (e.g., disk array storage devices, and tape libraries). Fibre channel enables almost limitless numbers of devices to be interconnected, and supports speeds of up to five times the current protocols and distances of up to 10 kilometers between system and peripheral device. However, fibre channel is not a secure protocol.
Fibre channel networks generally control access to data according to logical unit numbers (LUNs), which are allocated to portions of the data storage capacity in the SAN. For example, a LUN can be assigned to multiple disks in an array device, or to a single tape, or to a portion of a hard disk. Each LUN appears to an operating system (OS) as a logical device.
A World Wide Name (WWN) is a permanent identifier, which can be used to uniquely identify any system or peripheral, or any port belonging to a system or peripheral. In a fibre channel network, a host can be granted authorization to access a certain LUN by associating a WWN of the host (or of a port of the host) with the LUN. However, because of the any-to-any communication nature of the fibre channel network, an unauthorized host may be able to gain access to a LUN by stealing the identity, i.e., spoofing the WWN, of a host authorized for that LUN.
SUMMARY OF THE INVENTION
One of the embodiments of the invention is directed to a method for processing a fibre channel (FC) layer service request at a target node of an FC network. Such a method may include: receiving a fibre channel (FC) layer service request from an initiator node; extracting a permanent and temporary identifier from the FC layer service request; and determining whether a match exists between the extracted temporary identifier and a temporary identifier stored in association with the extracted permanent identifier.
Another of the embodiments of the present invention is directed to a method for processing a port login (PLOGI) request at a target node of an FC network. Such a method may include: receiving the PLOGI request from an initiator node; extracting a permanent identifier from the PLOGI request; and determining whether a match exists between the extracted permanent identifier and a stored permanent identifier.
Another of the embodiments of the present invention is directed to an access security device for controlling access to a target node in an FC network. Such a device may include: request processing means for extracting a permanent identifier and a temporary identifier from a received FC layer service request, the extracted permanent identifier and the extracted temporary identifier corresponding to an initiator node; lookup means for performing a lookup of a login table using the extracted permanent identifier to detect a temporary identifier stored in association with the extracted permanent identifier in the login table; and request invalidation means for rejecting the FC layer service request if the extracted temporary identifier does not match the detected temporary identifier.
Another of the embodiments of the present invention is directed to a code arrangement on a computer-readable medium for use in a system comprising an FC switch, a device connected to the FC switch, and one or more hosts connected to the FC switch, each of the hosts having an associated permanent identifier and temporary identifier, execution of the code arrangement preventing any of the hosts to gain access to the device by spoofing a permanent identifier associated with another host. Such a computer-readable code arrangement may include: a login table including one or more permanent identifiers, each of the permanent identifiers in the login table being stored in association with a temporary identifier; and a service request filtering code for receiving an FC layer service request sent by an initiator host to the device, the FC layer service request including a temporary identifier of the initiator host and a permanent identifier; extracting the temporary identifier of the initiating host and the permanent identifier from the FC layer service request; and performing a lookup of the login table using the extracted permanent identifier to determine whether the initiator host has permission to access the device.
Other features and advantages of the invention will become more apparent from the detailed description hereafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from the detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIG. 1 is a block diagram illustrating a system for implementing one embodiment of the invention.
FIG. 2 is a sequence diagram illustrating the process by which a device uses a login table and a login history table to authorize a first port login (PLOGI) request received from a host according to one embodiment of the invention.
FIG. 3 is a sequence diagram illustrating the process by which a device rejects a PLOGI request received from a host according to one embodiment of the invention.
FIG. 4 illustrates a process by which a device authorizes a PLOGI request whose WWN contains no entry in the login history table, according to one embodiment of the invention.
FIG. 5 is a sequence diagram illustrating the process by which a device determines that a possible security breach has occurred based on a login history table according one embodiment of the invention.
FIG. 6 is a sequence diagram illustrating the process by which a fibre channel (FC) switch authorizes a host's PLOGI request to log into a device according to one embodiment of the invention.
FIG. 7 is a sequence diagram illustrating the processing of an FC layer service request whose WWN is actively logged into the target device according to one embodiment of the present invention.
FIG. 8 is a sequence diagram illustrating the processing of an FC layer service request whose WWN is not actively logged into the target device according to one embodiment of the present invention.
FIG. 9 is a sequence diagram illustrating the processing of a registered state change notification (RSCN) request by the target device according to one embodiment of the present invention.
FIGS. 2-9 are UML sequence drawings. Messages and/or actions are depicted with arrows of different styles. A indicates a message that expects a response message. A indicates a response message.
DETAILED DESCRIPTION OF THE EMBODIMENTS
The following description of embodiments of the invention is merely illustrative in nature, and is no way intended to limit the invention, its application, or uses.
In a fibre channel (FC) network, an initiator node may send one or more FC layer service requests to be processed by a target node. Such service requests may include port login (PLOGI) requests, registered state change notifications (RSCNs), discover address (ADISC) requests, and discover port (PDISC) requests.
For example, an initiator node (e.g., a host) can transmit a PLOGI request to a target node (e.g., a storage device) in order to login and gain access to the data stored within the target node. In the embodiments presented below, the initiator node and target node will be described as a host and a storage device for the sake of convenience. However, it should be noted that the initiator node and target node of the invention are not so limited. The target node of the invention should be construed to cover any type of device, peripheral, system, etc. capable of performing FC layer service requests. Likewise, the initiator node includes any type of system, device, peripheral, routers, bridges, etc. capable of requesting FC layer services from such target nodes.
In one embodiment according to the invention, a PLOGI request, like other FC layer service requests, includes a World Wide Name (WWN) associated with the port of the host from which the request is sent. A WWN is an example of a permanent identifier, which is assigned by a name registration authority. Examples of WWNs include World Wide Port_Names (WW_PN) that identify ports of a node, and World Wide Node_Names (WW_NN) that identify nodes in the network. One or both of the WW_PN and the WW_NN may be included in an FC layer service request.
In one embodiment of the present invention, the WW_PN or a portion thereof, may be used as a permanent identifier. However, the invention should not be construed as being limited to this embodiment. For example, in one embodiment of the invention, a combination of the WW_PN and the WW_NN. Other types of nonvolatile identifiers assigned to a node or node port of an FC network, as will be contemplated by those of ordinary skill in the art, may be used.
The PLOGI request also includes a source identifier (SID) assigned to the host. An SID is an example of a temporary identifier, which is assigned by the FC network to nodes of the systems and devices connected to the network. An implicit security feature of FC networks prevents two different nodes from using the same SID.
In FC service layer requests, the SID may comprise a port identifier (Port_ID) used to identify the port of a node that originates the request. In one embodiment of the present invention, the Port_ID may be used as the temporary identifier. However, the present invention should not be construed as thus limited, and other types of temporary identifiers, as will be contemplated by those of ordinary skill in the art, may be used.
A storage device may maintain a data structure (i.e., login table) storing the WWN and SID of each PLOGI request processed by the device. In conventional FC networks, a storage device verifies a received PLOGI request by making sure that the SID in the request is different from every other SID in the login table. If so, the storage device allows the host, which sent the PLOGI request, to access LUNs associated with the WWN in the PLOGI request. Accordingly, if the requesting host is spoofing the WWN of another host, it can access any data assigned to the other host in the storage device.
To solve this problem, additional security may be implemented according to one embodiment of the invention. In this embodiment, a storage device receiving a PLOGI request extracts the WWN and the SID from the PLOGI request, and performs a lookup of the login table based on the extracted WWN. If this lookup determines that there is no entry in the login table corresponding to the WWN extracted from the PLOGI request (e.g., the extracted WWN does not match any of the WWNs stored in the login table), the device concludes that no other host is actively logged into the device using the same WWN.
However, if there is an entry in the login table storing the extracted WWN in association with an SID, the device compares the extracted SID of the PLOGI request with the SID in the login table. If these SIDs do not match, the device is alerted that a possible spoofing of the WWN has occurred, and thereby refuses to process the PLOGI request by sending a service reject (LS_RJT) notification to the requesting host. The device may also initiate a logout (LOGO) of the other hosts, which are already actively logged in. In case the extracted SID matches the SID in the login table, the device continues to operate with that host.
When the storage device does not find a login table entry corresponding to the extracted WWN based on the login table lookup, the device may further perform a login history table lookup based on the extracted WWN to verify the PLOGI request. Each entry in the login history table contains a WWN, and the most recent SID used in connection with that WWN to log into the device. Accordingly, if the login history table has an entry for the extracted WWN, the device compares the extracted SID of the PLOGI request with the SID stored in this entry. If these SIDs match, the PLOGI request may be verified and processed by the device.
If the SIDs do not match, the device may be alerted that a possible spoofing of the WWN has occurred, and a warning may be generated in a user-viewable console or user interface at the storage device. Such a warning may also be recorded in logs maintained by the storage device and later reviewed by personnel. Accordingly, personnel responsible for maintaining the storage device may be alerted if a possible security breach has occurred. In addition, or as an alternative, a security breach warning may be sent to a remote user console from the device, or to other network components that perform security functions for the FC network.
The lookup performed on the login table can be referred to as an active PLOGI security process because it checks the PLOGI request against actively logged-in hosts. The lookup of the login history table to be referred to as an inactive PLOGI security process because it verifies the PLOGI request against PLOGI requests received from hosts, which are no longer actively logged in.
It should be noted that the active PLOGI security process can also be performed for other types of FC layer service requests, including registered state change notifications (RSCNs), discover address (ADISC) requests, or discover port (PDISC) requests. In these instances, the device receiving the request extracts the WWN and the SID from the request, and performs a lookup of the login table using the extracted WWN. If the lookup indicates that the extracted WWN is not currently logged into the device, the device can reject the host's request by issuing an LS_RJT that notifies the host that a PLOGI request is required. If the WWN is logged in, the device will compare the extracted SID with the SIDs stored in the login table in association with the extracted WWN, in order to determine whether or not to process the request. If the SIDs match, the received request will be processed; if not, the device sends a LS_RJT of the requesting hosts.
According to an alterative embodiment of the invention, an FC switch may verify a PLOGI request sent by a host to a storage device. The FC switch may require hosts and devices to perform fabric logins (FLOGIs) in order to transmit and receive data via the switch. In this embodiment, when an initiator host sends a PLOGI request destined for a particular target device, the FC switch can extract the WWN and the SID from the PLOGI request, and perform a lookup of a fabric login table (FLOGI table), which stores the WWNs and SIDs associated with the processed FLOGI requests. Thus, the FC switch ensures the consistency of the WWN contained in the FLOGI request and the PLOGI request sent by the same host.
FIG. 1 is a block diagram of a system implementing the invention according to one embodiment. An FC network 100 includes a host 10 having a port 17 , which is connected to port 22 A of an FC switch 20 via fibre channel. The FC switch 20 includes a switch controller 24 , which is operable to connect port 22 A to port 22 B. Port 22 B is connected, via fibre channel, to port 32 of a device 30 , which includes a device controller 34 , a login table 36 , and a login history table 38 . It should be noted that FIG. 1 is merely illustrative, and does not limit the invention. For example, according to one embodiment, port 17 of the initiator host 10 may be directly connected to port 32 of device 30 . In another alternative embodiment, the FC network 100 may include an arbitrated loop configuration.
The device controller 34 of device 30 may comprise one or more processors, or other types of hardware known in the art, for processing FC layer service requests received by port 32 . The received service request may be processed by extracting the WWN and the SID from the request. The device controller 34 may further include one or more processors and/or hardware for performing a lookup of the login table 36 and the login history table 38 based on the extracted WWN, and determining whether or not the service request is valid based on the lookups. Although the login table 36 and the login history table 38 are described above as being implemented in the device 30 , the invention is not thus limited. The login table 36 and/or the login history table 38 may be located at alternative locations in the FC network 100 accessible to the device 30 , even though such alternative locations may sometimes be less efficient.
The host 10 may include one or more processors and/or hardware devices for generating an FC layer service request, and transmitting the service request from port 17 to a destination node in the FC network 100 . The host 10 may be connected to one or more work stations 13 , which allow users to access data and perform other operations on the FC network using the host.
An FC switch 20 for connecting the host 10 to the device 30 may be a fabric switch, which may include a switch controller 24 operable to process FLOGI requests and relay FC layer service requests and messages between the nodes of the FC network 100 . As noted above, the invention does not require an FC switch 20 , and equally applies to an FC network 100 that connects nodes via a hub or client-to-client configuration.
Also, the switch controller 24 may be operable to check the uniqueness of the WWN in a PLOGI request sent by initiator host 10 to target device 30 , as discussed above with respect to an alternative embodiment. In this embodiment, the switch controller may include a processor and/or hardware for extracting the WWN and the SID from the PLOGI request, and performing a lookup of a FLOGI table 26 containing the WWN and SID of each node currently logged into the switch 20 . The FLOGI table 26 is shown in FIG. 1 in a dotted box to indicate that it is associated with an alternative embodiment, and therefore not required by the invention.
The operation of the elements shown in FIG. 1 will be described below in connection with FIGS. 2-7 . These figures are for purposes of illustration only, and do not limit the invention.
FIG. 2 is a sequence diagram illustrating the operation by which a device 30 verifies a PLOGI request received from a host 10 based on the login table 36 and login history table 38 . The host 10 initially sends an FLOGI request 200 from its port 17 to port 22 a of the FC switch 20 in order to perform fabric login. The FC switch verifies the FLOGI request (as indicated by self-message 205 ), and sends a return 210 to the host 10 indicating that fabric login has been performed. The host 10 then sends a PLOGI request 215 to the FC switch 20 , which is then relayed from port 22 b of the FC switch 20 to port 32 of the device 30 .
As described above, this PLOGI request includes a WWN of the port 17 from which the host 10 transmitted the request, or alternatively, contains a WWN assigned to the host 10 itself. The device controller 34 extracts the WWN and the SID from the PLOGI request, and sends the extracted WWN to the login table 36 as shown by message 225 in order to perform a lookup in the login table 35 using this WWN.
According to self-message 230 , the login table 36 performs the lookup. Since there is no matching entry indicating that the extracted WWN is actively logged into the device 30 , message 235 indicates to device 30 that no match has been found in the login table 36 . Subsequently, the device 30 performs inactive PLOGI security processing by sending the extracted WWN 240 to the login history table 38 . A lookup of the login history table 38 is performed based on the extracted WWN as indicated in self-message 245 . When an entry in the login history table 38 is found containing the extracted WWN, the associated SID contained in that entry (referred to as the preceding SID) is sent back to the device 30 in message 250 . Accordingly, if device 30 determines that the preceding SID of the login history table 38 matches the extracted SID, the device 30 will perform the port login for the initiator node 10 , and send an accept message (ACC) 260 indicating that the host 10 is logged in.
FIG. 3 is a sequence diagram illustrating the operation by which a device 30 rejects a PLOGI request from an initiator node 10 based on a login table lookup according to the active PLOGI security processing. Similar to messages 200 - 210 of FIG. 2 , messages 300 - 310 show the initiator host 10 performing an FLOGI with the FC switch 20 . Further, similar to messages 315 - 330 , the PLOGI request is sent from the initiator node 10 to the device 30 via FC switch 20 , and a lookup is performed in login table 36 based on the extracted WWN of the request.
However, in the example of FIG. 3 , the login table 36 includes an entry corresponding to the extracted WWN including an associated SID. The associated SID is transmitted back to the device 30 in message 335 , and the device 30 determines that the associated SID does not match the extracted SID. Accordingly, the device 30 determines that another host is already logged into the device 30 using the same WWN extracted from the PLOGI request. The device 30 is therefore alerted that a possible WWN spoofing has occurred and sends an LS_RJT in message 340 , which is relayed by the FC switch 20 as LS_RJT message 345 to the host 10 , thereby rejecting the PLOGI request. The device 30 may also be configured to initiate a LOGO (not shown in FIG. 3 ) for the other host using the extracted WWN. The device 30 may do so based on the fact that the other host may have spoofed the WWN associated with the initiator host 10 .
FIG. 4 is a sequence diagram illustrating the operation whereby device 30 verifies a PLOGI request, containing a WWN having no corresponding entry in a login history table 38 for the device 30 . The operations illustrated in FIG. 4 are the same as those in FIG. 2 up to the point where the device 30 performs a lookup of the login history table 38 based on the extracted WWN i.e., messages 400 - 445 in FIG. 4 are the same as messages 200 - 245 in FIG. 2 . However, in FIG. 4 , the lookup of the login history table 38 determines that no proceeding SID is stored in association with the extracted WWN, (as indicated by message 450 ). The device 30 therefore indicates to the host 10 that the port login will be performed, as indicated by messages 455 and 460 . The device 30 also instructs the login history table to store the extracted SID in association with the extracted WWN in message 465 . The login history table 38 stores the extracted SID in association with the extracted WWN (e.g., in the same data record) as shown in self-message 470 . After the data is written to the login history table 38 , processing is completed as shown by return message 475 .
FIG. 5 is a sequence diagram illustrating the operation whereby the device 30 detects a possible security breach by determining that the extracted WWN of the PLOGI request has previously been logged into the device 30 with a different SID. The process of FIG. 5 is the same as FIG. 2 up to the point where the login history table 38 returns a preceding SID to the device 30 . Accordingly, messages 500 - 550 of FIG. 5 are the same as messages 200 - 250 of FIG. 2 . However, in FIG. 5 , the device 30 determines that the preceding SID of message 550 does not match the extracted SID of the PLOGI request. Accordingly, a security breach warning is generated in the device controller 34 (for example, in a service processor) of device 30 .
According to one embodiment, as illustrated in FIG. 5 , the device 30 may provide a password lock feature in association with the security breach warning, which requires a password to be input at a user-accessible console or user interface at the device 30 in order for the device 30 to perform a port login of the initiator host 10 . Alternatively, a user may enter the password using a console or interface at another location via, e.g., TCP/IP services.
Message 555 may be displayed on the console or user interface of the device 30 to indicate that a password is required. Accordingly, the user may input the password 560 for authentication by the device 30 (in self-message 565 ). ACC messages 570 and 575 indicate that the password has been authenticated and the PLOGI request will be processed.
This password lock feature may be useful in situations where the FC network 100 assigns new SIDs to the nodes based on, for example, a reconfiguration of the network 100 or the addition of new nodes. However, in an alternative embodiment, the device 30 may respond to the security breach warning by merely denying the PLOGI request and sending a LS_RJT notification to the host 10 accordingly.
FIG. 6 is a sequence diagram illustrating an embodiment of the invention in which the FC switch 20 verifies a PLOGI request received from initiator host 10 for device 30 . According to messages 600 - 615 , the FC switch 20 performs a fabric login of host 10 . Thereafter, host 10 sends a PLOGI request 615 to the FC switch 20 , which then performs a lookup of the FLOGI table 26 using the extracted WWN 620 .
As indicated by self-message 625 , an entry in the FLOGI table 26 containing the extracted WWN is found. The associated SID in this entry is sent back to the FC switch 20 in message 630 . After determining the associated SID matches the extracted SID in the PLOGI request, the FC switch 20 sends the PLOGI request to the device 30 . The device 30 may then extract the WWN and SID from the request, and send them in message 640 to the login history table 38 . Self-message 645 shows the WWN and SID being stored in the login history table 38 , and return message 650 indicates completion of storage operation. The host 10 is notified that its PLOGI request has been verified by the FC switch 20 when it receives ACC message 655 .
FIG. 6 illustrates a situation where the FC switch 20 verifies a received PLOGI request according to a lookup of the FLOGI table 26 . However, if the extracted SID does not match the SID associated with extracted WWN in the FLOGI table 26 , the FC switch 20 may not send the PLOGI request to the device 30 . Further, the FC switch 20 may be configured to perform a fabric logout of any host 10 whose PLOGI request is rejected based on the lookup of the FLOGI table 26 .
The verification process illustrated in FIG. 6 , may be performed using any combination of hardware and/or software in an FC switch 20 contemplated by one ordinarily skilled in the art. In addition, an FC switch 20 may perform this procedure in conjunction with other feature, e.g., zoning, to provide added measures of security.
It should be noted that in this embodiment, the FLOGI table may be maintained in the FC switch 20 as shown in FIG. 1 . Alternatively, the FLOGI table 26 may be maintained elsewhere, e.g., at another location in the FC network 100 , although such alternative locations may be less efficient.
While FIGS. 2-6 illustrate situations where the initiator host 10 sends a PLOGI request to the device 30 , the invention can also be used with other types of FC layer service requests and commands as illustrated in FIGS. 7 and 8 . Such service requests may include discover address (ADISC) requests, discover port (PDISC) requests, and registered state change notifications (RSCNs). It should be noted that the foregoing list of FC layer service requests and commands is merely illustrative and not meant to be a comprehensive list of all requests and commands covered by the invention.
FIGS. 7 and 8 are sequence diagrams illustrating situations where the host 10 sends an FC layer request other than a PLOGI request to the device 30 . For the purposes of FIGS. 7 and 8 , it will be assumed that the FC switch 20 has already performed a fabric login of the requesting host 10 . Accordingly, the messages associated with sending and verifying an FLOGI request are not shown in either of these figures.
FIG. 7 is a sequence diagram illustrating the processing of an FC layer service request by the device 30 , in which the WWN of the service request is already actively logged into the device 30 . The initiator host 10 sends the FC layer service request in message 700 to the FC switch 20 , which relays the service request to device 30 in message 710 . The FC layer service request may be an ADISC or PDISC, as shown in FIG. 7 , or any other type of FC layer service request as will be contemplated by those ordinarily skilled in the art. The device 30 extracts the WWN and SID from the received service request, and sends the extracted WWN to the login table 36 in message 715 .
A lookup is performed on the login table 36 based on this extracted WWN, as indicated by self-message 720 . Since the extracted WWN is already logged in, the lookup of the login table 36 will return an SID associated with the extracted WWN in message 725 . The device 30 then compares the extracted SID with the returned SID in order to determine whether a match occurs. If SIDs match, ACC messages 730 and 735 indicate to the host 10 either the results of the processed service request, or that the service request will be processed by the device 30 . However, if the device 30 determines that SIDs do not match, and that the initiator host 10 may be spoofing a WWN of another host, the device 30 will send a LS_RJT notification via messages 730 and 735 to the host 10 .
It should be noted that in FIG. 7 , if the FC layer service request is verified based on the login table 36 lookup, the device 30 does not need to write the extracted WWN and SID to the login history table 38 . This step will have already been performed at the time the device 30 initially processes the PLOGI of the host 10 .
FIG. 8 is a sequence diagram illustrating a situation in which the WWN of the FC layer service request is not actively logged into the device 30 . Processing in FIG. 8 is the same as that in FIG. 7 up to the point where the device 30 initiates the lookup of the login table 36 using the extracted WWN. Accordingly, messages 800 - 820 of FIG. 8 are the same as messages 700 - 720 shown in FIG. 7 .
However, based on the lookup of the login table 36 in FIG. 8 (self-message 820 ), the device 30 is notified by message 825 that no SID is stored in the login table 36 in association with the extracted WWN. The device 30 determines that the extracted WWN is not currently logged in. Accordingly, the device 30 may send an LS_RJT notification to the host 10 , via FC switch 20 , indicating that a PLOGI is required by the host 10 in order to process the FC layer service request.
In an alternative embodiment, the device 30 may respond to message 825 by performing another lookup of the login table based on the extracted SID to determine whether the host 10 has already logged into the device 30 using another WWN. If this secondary lookup (which is not shown in FIG. 8 ) indicates that the host 10 is actively logged into the device 30 using another WWN, the device 30 may perform a LOGO of the host 10 . If the secondary lookup of the login table 36 indicates that the host's SID has not yet been logged into the device 30 , the LS_RJT notification requiring a PLOGI may then be transmitted to the host 10 .
FIG. 9 is a sequence diagram illustrating the processing of a registered state change notification (RSCN) request by the device 30 according to one embodiment. The FC switch 20 may send the RSCN request in message 900 to inform the device 30 whether the host 10 is “ready” to communicate (e.g., when link connectivity is established between the host 10 and the link 20 ). Accordingly, the device 30 extracts the WWN and SID from the RSCN, and sends the extracted WWN in message 915 to the login table 36 . Based on a lookup performed using the extracted WWN, the login table 36 sends an associated SID in message 925 to the device 30 . If the associated and extracted SIDs match, the device 30 sends an ACC to the FC switch 20 in message 930 to indicate that the host 10 is allowed to communicate to the device 30 . Alternatively, if the SIDs do not match, an LS_RJT will be sent in message 930 to the FC switch 20 .
If the FC switch 20 receives and ACC from the device 30 in message 930 , a port will be established in the switch 20 between the host 10 and the device 30 . Alternatively, if a LS_RJT is received in message 930 , the FC switch 20 will not establish such a port. The host 10 may query the FC switch 20 to determine whether a port has been established to the device 30 by sending a name service check, as shown in 935 . The FC switch 20 may respond to the name service check in message 845 by indicating whether or not a port between the host 10 and the device 30 has been established.
Although FIGS. 2-9 above illustrate the processed FC layer service request as being one of a PLOGI, ADISC, PDISC, and RSCN, the processed FC layer service request is not thus limited. Security processing may be performed on any FC layer service request as will be contemplated by those of ordinary skill in the art.
According to one embodiment, inactive PLOGI security processing may be turned off or deactivated during certain situations. For example, a flag may be set in the device 30 for disabling security processing during these situations. When the inactive PLOGI security processing is turned off, the login history table 38 will be deactivated and unable to process any lookup requests. Accordingly, any received PLOGI request can be verified by the device 30 based only on a lookup of the login table 36 (i.e., based solely on the active PLOGI security feature).
Accordingly, the login history table 38 may be deactivated immediately after an initial set up of the FC network 100 , or after a reconfiguration of the network 100 in which one or more systems or peripherals are added, removed, or relocated. As a result of such changes, the network 100 may need to assign different SIDs to the hosts, and the WWN-SID associations in a login history table 38 will need to be updated. Deactivation of the inactive PLOGI security processing may also occur after an initial set up of the device 30 because the login history table 38 will not include any entries since no port logins have been performed for the device 30 . Security processing may be reactivated after the initial set up or reconfiguration (e.g., by resetting a flag in the device 30 to enable security processing). The reactivation of security processing may be performed either by automated means, or manually via a user interface of the device 30 .
The invention being thus described, it will be apparent that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be readily apparent to one skilled in the art are intended to be included in the scope. | A method for processing a fiber channel (FC) layer service request at a target node of an FC network may include receiving the FC layer service request from an initiator node, extracting a permanent identifier and a temporary identifier from the received FC layer service request, and determining whether a match exists between the extracted temporary identifier and a temporary identifier stored in association with the extracted permanent identifier. A security access device and computer-readable code arrangement may include similar features. | 7 |
CROSS REFERENCES TO RELATED APPLICATIONS
This application is a continuation in part and claims the benefit of now abandoned U.S. Provisional Application No. 60/783,687, filed Mar. 17, 2006, the complete disclosure of which is herein incorporated by reference.
BACKGROUND OF THE INVENTION
In the sport of fly fishing, it is common for the fisherman to use a landing net to facilitate the removal of the caught fish from the water. Nonetheless, the landing net is only used occasionally. It is therefore desirable for the landing net to be readily accessible when needed, but to be stored in a location that does not interfere with routine fishing operations such as moving through brush or other obstacles to the fishing site, casting a fly, or operating a rod and reel. The prior art contains several systems for attaching a landing net to a garment worn by the fisherman. For example, Sargent U.S. Pat. No. 1,024,653 describes a device which comprises a clip adapted to removably hold the round handle of a landing net in a vertical position on the back of a fisherman's garment. Braken U.S. Pat. No. 2,717,391 discloses a fishing garment having a loop that extends down from the neck along the back panel of the garment and carries a ring to which a landing net may be attached. Farber U.S. Pat. No. 4,723,695 describes a pouch-like support adapted for attachment to the back of a fisherman's garment for removably accommodating a landing net. The complete disclosures of all these references are herein incorporated by reference.
Many currently commercially available fishing vests have a single ring sewn near the top of the vest to allow a landing net to be clipped onto the vest using a detachable clip or magnet attached to the net handle. This arrangement works well while the fisherman is standing vertically, but whenever the fisherman bends over, e.g. to grab something, to duck under an obstruction, to work on something, etc., the net may slip off the fisherman's back, swing to the side, and fall into the fisherman's face or otherwise interfere with the fisherman's activities. This may happen many times during the day and can be annoying.
SUMMARY OF THE INVENTION
The present invention relates to a fishing garment system and method wherein a landing net may be removably secured to the back of a garment, waders, other clothing, fishing vest or the like, and yet stay in place when the fisherman bends over, leans to the side or otherwise moves. In one embodiment, a fishing net system comprises a handle having a top and a bottom. A loop extends from the bottom of the handle, and a mesh is attached to the loop. A connector system is operably coupled to the fishing net at a location spaced apart from the top of the handle. The connector system is configured to removably couple the fishing net to a user's back. In this way, the connector system may be used to hold the net in place on the user's back when not in use.
A variety of connector systems may be used to couple the fishing net to the user's back, and may be integrally formed with the net, removably attached or may be provided as a retrofit item. One example of a connector system comprises at least one magnet that is coupled to the handle near where the handle reaches the loop. Another example is a first pair of magnets positioned on opposite sides of the mesh, and a second pair of magnets configured to be placed on opposite sides of a user's garment.
In some cases, the fishing net will also have a coupling system that is coupled to the top end of the handle. With this configuration, the coupling system and the connection system secure the landing net in a vertical position on a back a user's garment when not in use.
In a further embodiment, the invention provides a kit for removably coupling a landing net to a user's garment. The kit comprises a connection system that is configured to secure the landing net in a vertical position on the back panel of the fishing garment when not in use, and the connection system comprises a net portion and a garment portion. The kit further includes instructions for using the connection system. The instructions may include steps for removably coupling the net portion to the landing net and the garment portion to the garment, and for removably coupling the landing net to the garment using the net portion and the garment portion.
In yet another embodiment, a fishing garment system of the invention comprises a fishing garment, e.g. a vest, having a back panel with a top section and a middle section, and a landing net having a handle and a loop with attached mesh. A first connection system is provided that removably couples the end of the landing net handle to the top section of the garment back panel and a second connection system is provided that removably couples the intersection of the handle and loop of the landing net to the middle section of the garment back panel.
In preferred embodiments, the first and second connection systems each comprise a pair of complementary connectors that removably couple with each other. In one embodiment, the first connection system may comprise a ring attached to the garment back panel and a clip attached to the landing net handle. In other embodiments, the first connection system may comprise a first and a second magnet, one magnet and a metal plate to which the magnet is attracted, or a first and a second hook and loop fastener (e.g. Velcro® tape), one of which is attached to the back panel of the garment and the other of which is attached to the landing net handle.
In one embodiment, the second connection system may comprise a first magnet and second magnet, one magnet and one metal plate attractive to the magnet, or a first and a second hook and loop fastener. One of these connectors may be attached to the middle section of the back panel of the fishing garment, and the other connector may be attached to the intersection of the handle and the loop on the landing net. In one embodiment, one of these connectors may be disposed on the surface of a support that is clipped onto, or sewn into, the fabric in the middle section of the back panel, and one of the connectors may be disposed on a connecting adaptor comprising a circumferential strap adapted to wrap around the landing net handle and a middle strap adapted to engage the circumferential strap at each end thereof and wrap around the landing net loop at the intersection of the handle and the loop.
A method is also provided for attaching a landing net to the back panel of a fishing garment, which comprises the steps of removably coupling the handle of the landing net to the top section of the back panel; and removably coupling the intersection of the handle and loop of the landing net to the middle section of the back panel.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a rear perspective view of a fishing garment system according to one embodiment of the present invention.
FIG. 2 illustrates a perspective view of one embodiment of an alternative connection system according to the invention.
FIGS. 3A and 3B illustrate perspective views of alternative embodiments of a connecting panel adapted to be attached to the rear panel of a fishing garment.
FIGS. 4A and 4B illustrate perspective views of one embodiment of a connecting adaptor adapted to be attached to the intersection of the handle and loop of a landing net.
FIGS. 5A and 5B illustrates perspective view of another embodiment of a connecting system that may be used to removable couple a landing net to a user's garment.
DETAILED DESCRIPTION OF THE INVENTION
The invention will be further described with reference to the drawings. The same number is used in different drawings to refer to the same elements.
The invention provides a variety of techniques for securing a fishing net to a garment or other article. For example, the techniques of the invention may be used to removably couple a fishing net to a fishing vest, chest waders, shirts, jackets or other types of apparel and garments. To removably couple the fishing net to such articles, a variety of techniques may be used. Typically, such nets will be configured to clip to a garment, such as at the end of the handle. Some aspects of the invention provide an additional removable coupling arrangement somewhere on the article being worn by the fisherman to prevent the net from swinging side to side or even over the top of the fisherman. Such a removable coupling arrangement can be integrally formed with the net or may be a removable coupling arrangement. In this way, the coupling arrangement may be sold as an integral part of the net or may be retrofit. Similarly, the connection system may be an integral part of the clothing or garment, or may be attached after purchasing the garment. Further, the coupling arrangement may be provided anywhere along the net or on the garment, but will typically be located somewhere along the handle and the back of the user.
Some of the embodiment may use magnets to removably couple the net to the garment, although other connectors may be used, such as a hook and loop fastener material. When magnets are used, they may be provided in pairs so that they may be easily be coupled to the net or clothing with essentially no alterations. For example, one pair of magnets may be placed on opposite sides of the net's mesh and the other pair may be placed on opposite sides of the garment. The first pair of magnets may then be coupled to the second pair to secure the net to the garment.
FIG. 1 illustrates one embodiment of a fishing garment system 10 according to the invention. Fishing garment 10 comprises a fishing vest 100 having a back panel with a top section 101 and a middle section 102 . Landing net 105 comprises handle 106 and loop 107 to which mesh 108 is attached. In accordance with the present invention, a first connection system 109 removably couples handle 106 of landing net 105 to vest 100 , and a second connection system 110 removably couples intersection 114 of landing net 105 (where handle 106 joins loop 107 ) to vest 100 . However, it will be appreciated that the second connection system 110 could be located anywhere along handle 106 , on loop 107 , or at multiple locations on the net 105 .
As illustrated in FIG. 1 , first connection system 109 comprises ring 112 secured to top section 101 of vest 100 and clip 113 , which is attached to end 111 of handle 106 . Clip 113 is adapted to engage ring 112 when landing net 105 is not in use, and is adapted to disengage ring 112 when landing net 105 is needed. FIG. 2 illustrates an alternative first connection system 209 that removably couples ring 112 of vest 100 to handle 106 of landing net 105 . Connection system 209 comprises a first magnet 201 secured to ring 112 and a second magnet 202 secured to handle 106 . When landing net 105 is not in use, first magnet 201 and first magnet 202 are engaged by magnetic attraction. When it is desired to use landing net 105 , magnets 201 and 202 are pulled apart with moderate force, whereupon magnet 201 remains attached to ring 112 and magnet 202 remains attached to the released landing net 105 .
Referring again to FIG. 1 , a second connection system 110 is provided that removably couples landing net 105 to vest 100 at the intersection 114 of handle 106 and loop 107 . As shown in FIG. 1 , second connection system 110 comprises connecting panel 115 (e.g. as shown in FIGS. 3A and 3B ) secured to middle section 102 of vest 100 and connecting adaptor 116 (e.g. as shown in FIGS. 4A and 4B ) secured to intersection 114 of landing net 105 .
FIG. 3A illustrates one embodiment of connecting panel 115 , which may comprise a support 301 having connector 302 disposed on its upper surface 303 . Pin 304 is attached through hinge 305 to lower surface 306 of support 301 . The end of pin 304 is adapted to pierce the fabric of middle section 102 of vest 100 and then engage hook 307 , thereby securing connecting panel 115 to vest 100 . In this way, a connection system may easily be retrofit to existing clothing or garments.
FIG. 3B illustrates another embodiment of connecting panel 115 comprising support 307 having connector 308 disposed on its upper surface. Connecting panel 115 may be sewn into the fabric of middle section 102 of vest 100 with stitches 309 , thereby securing connecting panel 115 to the back panel of vest 100 . Panel 115 may be provided at the time best 100 is manufactured, or at a later time.
FIG. 4A illustrates one embodiment of connecting adaptor 116 , which may comprise circumferential strap 401 adapted to wrap around handle 106 of landing net 105 ( FIG. 1 ) and middle strap 402 adapted to engage circumferential strap 401 at each end thereof and wrap around loop 107 of landing net 105 at intersection 114 of handle 106 and loop 107 ( FIG. 1 ). Circumferential strap 401 and middle strap 402 may be made from any suitable material, e.g. nylon, rubber, canvas, etc. Circumferential strap 401 may comprise a continuous circle that can be slid over handle 106 (as shown in FIGS. 4A and 4B ), or a linear strip the ends of which may be secured together after wrapping around handle 106 , e.g. using a hook and loop fastener such as Velcro® tape.
As shown in FIG. 4B , middle strap 402 may comprise a linear strip, one or both ends of which are secured to circumferential strap 401 using Velcro® tape 404 . Connector 403 may be disposed on the outer surface of circumferential strap 401 . When positioned on landing net 105 , adaptor 116 covers the intersection 114 of handle 106 and loop 107 , with connector 403 facing connecting panel 115 so as to engage the connector thereon. In some cases, connector 403 could be coupled with an adhesive, placed into a bored out hole in the net, or the like. Also, in one option, some or all of the net itself could be constructed of a metal so that it will easily couple to a magnet on the fishing vest, or vice versa.
The connectors used on connecting panel 115 and adaptor 116 may be any complementary connectors that secure landing net 105 to vest 100 when landing net 105 is not in use, yet pull apart when moderate force is applied to remove landing net 105 from vest 100 . For example, the connectors on both connecting panel 115 and adaptor 116 may comprise first and second magnets that attract each other, or one connector may be a magnet and the other connector may be a metal plate to which the magnet is attracted. Alternatively, the connectors may comprise first and second hook and loop fasteners such as Velcro® tape. As a further example, one connector may be a ring and the other connector may be a spring-loaded hook or clip that releases from the clip when moderate force is applied.
The present invention is suitable for retrofitting fishing vests that are currently available at a variety of retail outlets. For example, many fishing vests now come equipped with a ring on the top of the rear panel, such as ring 112 shown in FIG. 1 , and many landing nets include a handle clip such as clip 113 shown in FIG. 1 . All that is required to take advantage of the present invention with such an arrangement would be to secure a connecting panel, such as connecting panel 115 shown in FIGS. 3A and 3B , to the middle section of the vest and to install a connecting adaptor, such as connecting adaptor 116 shown in FIGS. 4A and 4B , on the landing net so that the connector on the connecting adaptor engages with the connector on the connecting panel. Alternatively, a new vest may be manufactured with the connecting panel integrated into the back of the vest and/or a new landing net may be manufactured with a connector integrated into the intersection of the landing net.
Another embodiment of a system that may be used to easily retrofit a fishing net and garment with connectors is illustrated in FIGS. 5A and 5B . FIG. 5A illustrates a net connection system 500 that comprises a pair of magnets 502 and 504 . Magnets 502 and 504 may be encased in a plastic or other protective material that permits the two magnets to easily interlock when attracted to each other. For example, the plastic may having interlocking features, teeth or detents which permit that magnets to interlock and keep from rotating relative to each other. Connection system 500 may be placed on either sides of the mesh 508 of a fishing net 509 . In this way, the fishing net may easily be retrofit to include a connector. Typically, the magnets 502 and 504 will be placed on the mesh within a few inches of where the handle meets the loop, although other locations are possible.
FIG. 5B illustrates a garment connection system 510 that comprises magnets 512 and 514 which may be constructed in a manner similar to magnets 502 and 504 . In this way, magnets 512 and 514 may be placed on opposite sides of a garment 516 , such as a fishing vest, to hold the magnets to the garment.
When systems 500 and 510 are coupled to the net and the garment, they may be coupled together simply by hanging the fishing net from the user's back and permitting the two pairs of magnets 502 , 504 and 512 , 514 (which are attracted to each other) to couple to each other. By wiggling the net or the user's back, the two pairs of magnets will come close enough to each other to couple together.
This configuration permits a retrofit kit to be sold which includes four magnets and instructions for use. Such a system is inexpensive and easy to use.
The foregoing description is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact details shown and described herein, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. Thus, it will be apparent to those skilled in the art that many changes and substitutions can be made to the preferred embodiments herein described without departing from the spirit and scope of the present invention as defined by the appended claims. | A fishing net system comprises a handle having a top and a bottom. A loop extends from the bottom of the handle, and a mesh is attached to the loop. A connector system is operably coupled to the fishing net at a location spaced apart from the top of the handle. The connector system is configured to removably couple the fishing net to a user's back. A method is also provided for attaching a landing net to the back panel of a fishing garment, which includes the steps of removably coupling the handle of the landing net to the top section of the garment; and removably coupling the landing net to the middle section of the garment. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is claiming the benefit of the Jan. 13, 2003 filing date of provisional Patent Application No. 60/439,815, entitled “KIT AND METHOD FOR MAKING AND SUBMITTING INFANT FOOT PRINTS TO SERVICE COMPANY FOR REPRODUCTION ONTO BIRTH ANNOUNCEMENTS AND RELATED GIFTS”.
FIELD OF THE INVENTION
[0002] This invention relates generally to arts and crafts and, more specifically, to an impression medium for preserving handprints and footprints for reproduction.
BACKGROUND OF THE INVENTION
[0003] Birth announcements and related gifts have long been used by parents to announce the birth of a child. Currently, one desiring to employ the service of an announcement printing company is generally limited to providing the infant's birth information and occasionally a photograph for reproduction onto announcements.
[0004] Alternatively, parents may purchase kits that provide a keepsake certificate and paint or ink for making an imprint on the certificate. However, these kits do not allow for multiple announcements that can be mailed or otherwise easily shared with family and friends. Furthermore, these kits typically do not provide printed birth information, thus requiring the user to hand-write the infant birth information onto the certificate.
[0005] Therefore a need existed for an impression medium for preserving handprints and footprints for reproduction onto personalized keepsakes. Preferably, the device is used for infants. Still further, preferably, the preserved handprints and footprints allow for convenient reproduction of the handprints and footprints along with printed birth information onto a set of birth announcements or gifts such as, but not limited to, keepsake birth certificates, mugs, t-shirts, and candy wrappers.
BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0006] In accordance with one embodiment of the present invention, an impression medium for preserving at least a portion of at least one of a handprint and footprint for reproduction onto birth announcements and related gifts is disclosed. The impression medium comprises, in combination, an imprint film, a printing medium coated onto a bottom surface of the imprint film, a printing surface proximate the bottom surface of the imprint film, and a substantially rigid backer dimensioned to be placed proximate a bottom surface of the printing surface.
[0007] In accordance with another embodiment of the present invention a method for preserving handprints and footprints for reproduction is disclosed comprising the steps of providing an impression medium for preserving at least a portion of at least one of a handprint and a footprint, recording at least one of a handprint and a footprint onto the impression medium, and copying at least one of the handprint and the footprint from the impression medium onto a personalized keepsake.
[0008] The foregoing and other objects, features, and advantages of the invention will be apparent from the following, more particular description of the preferred embodiments of the invention, as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] [0009]FIG. 1 is a top view of a keepsake birth certificate prior to receiving an imprint of a handprint or a footprint.
[0010] [0010]FIG. 2 is a perspective view of the keepsake birth certificate of FIG. 1 being placed between an imprint film and a backer of a first embodiment of an impression medium.
[0011] [0011]FIG. 3 is a top view of a hand being pressed onto the first embodiment of the impression medium. Also shown is an imprint protector sheet that must be removed prior to pressing the hand onto the impression medium.
[0012] [0012]FIG. 4 is a top view of a printing surface.
[0013] [0013]FIG. 5 is a perspective view of a foot being pressed onto a second embodiment of the impression medium.
[0014] [0014]FIG. 6 is a perspective view of a printing surface being removed from between an imprint film and a backer of the second embodiment of the impression medium after an imprint of a footprint has been recorded onto the printing surface.
[0015] [0015]FIG. 7 is front view of a footprint recorded onto the printing surface shown in FIG. 6.
[0016] [0016]FIG. 8 is a perspective view of a bottom surface of a hand coated with a chemically reactive solution.
[0017] [0017]FIG. 9 is a perspective view of the hand coated with a chemically reactive solution of FIG. 8 being pressed onto a sheet of chemically reactive paper.
[0018] [0018]FIG. 10 is a perspective view of a handprint of the hand of FIG. 9 recorded onto the chemically reactive paper.
[0019] [0019]FIG. 11 is a perspective view of a foot being pressed onto an inkpad.
[0020] [0020]FIG. 12 is a perspective view of a bottom surface of the foot shown in FIG. 11 coated with ink.
[0021] [0021]FIG. 13 is a perspective view of the coated foot of FIG. 12 being removed after a footprint has been recorded onto paper card stock.
[0022] [0022]FIG. 14 is a top view of footprints copied onto a personalized birth announcement.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] The novel features believed characteristic of the invention are set forth in the appended claims. The invention will best be understood by reference to the following detailed description of illustrated embodiments when read in conjunction with the accompanying drawings, wherein like reference numerals and symbols represent like elements.
[0024] The inventor has created an impression medium, referred to generically as impression medium 10 , that allows for the convenient recording of at least a portion of a footprint 31 (shown in FIGS. 6, 7, 13 and 14 ) or handprint 30 (shown in FIG. 10) for reproduction onto personalized keepsakes.
[0025] Referring now to FIGS. 2 - 3 , the preferred embodiment of the impression medium, referred to as impression medium 10 a, is shown. The main components of the impression medium 10 a include an imprint film 14 (shown in FIGS. 2, 3, 5 and 6 ), a printing medium 16 (shown in FIGS. 6 and 7) coated onto a bottom surface of the imprint film 14 (shown in FIGS. 2, 3, 5 and 6 ), a printing surface 19 (shown in FIGS. 4, 6, and 7 ) proximate the bottom surface of the imprint film 14 , and a substantially rigid backer 22 (shown in FIGS. 2 and 6) dimensioned to be placed proximate a bottom surface of the printing surface 19 . While it is preferred that the substantially rigid backer 22 be comprised of cardboard, it should be understood that substantial benefit may be derived from using plastic or any other substantially rigid material.
[0026] While, in the preferred embodiment, the impression medium 10 a is substantially rectangular, as shown for example in FIGS. 2, 3, 5 , and 6 , it should be understood that it is within the spirit and scope of this invention to provide an alternatively shaped impression medium, as desired for particular uses.
[0027] An alternative embodiment of the impression medium 10 a, referred to as impression medium 10 b, is shown in FIGS. 5 and 6. Impression medium 10 b is essentially the same as impression medium 10 a, except that the size of the imprint film 14 in impression medium 10 b is greater. Both impression medium 10 a and impression medium 10 b have a frame 11 (shown in FIGS. 2, 3, 5 and 6 ) coupled about the imprint film 14 . Preferably, a first edge 13 (shown in FIG. 2) of the frame 11 is pivotally coupled to a corresponding first edge 23 (shown in FIG. 2) of the backer 22 so as to allow the backer 22 to be folded so as to be proximate the printing surface 19 , although it should be clear that substantial benefit could be derived from an alternative embodiment of the present invention in which the backer 22 is coupled along another edge to the frame 11 or in which the backer 22 is completely separate from the frame 11 .
[0028] Referring now to FIGS. 2 - 3 , impression medium 10 a comprises a frame 11 that defines at least three windows 12 dimensioned to expose at least a portion of the imprint film 14 . Preferably, the exposed portions of the imprint film 14 are sized to fit a hand 32 (shown in FIG. 3) or a foot 34 (shown in FIG. 5).
[0029] Referring now to FIGS. 5 and 6, the frame 11 of impression medium 10 b defines one window 12 dimensioned to expose a greater portion of the imprint film 14 .
[0030] While FIGS. 3 and 5 depict an entire hand 32 and an entire foot 34 , respectively, being pressed onto the imprint film 14 , it should be clearly understood that substantial benefit may be derived from using a finger, a toe, a palm, a heel or any other portion of a hand 32 or foot 34 . It should also be understood that although an infant hand 32 or infant foot 34 is preferred, substantial benefit may also be derived from using the hand 32 or foot 34 of a child or even an adult.
[0031] Referring now to FIGS. 3 - 4 , it is preferred that the impression medium 10 a have an imprint protector sheet 24 (shown in FIG. 3) dimensioned to be placed between the bottom surface of the imprint film 14 (shown in FIG. 3) and a top surface 21 (shown in FIG. 4) of the printing surface 19 (shown in FIG. 4). The imprint protector sheet 24 prevents any handprints 30 or footprints 31 from being made inadvertently while handling the impression medium 10 a.
[0032] Prior to recording the handprint 30 or footprint 31 , the imprint protector sheet 24 should be removed (shown in FIG. 3). A printing surface 19 should then be placed between the imprint film 14 and the backer 22 . It is preferred that the printing surface 19 be either an imprint sheet 25 (shown in FIGS. 4, 6, and 7 ), card stock 26 (shown in FIG. 13), or artist board (not shown). It should be clearly understood, however, that substantial benefit may also be derived from using paper or any other medium capable of recording a handprint 30 or footprint 31 .
[0033] By pressing the hand 32 (shown in FIG. 3) or foot 34 (shown in FIG. 5) onto the imprint film 14 , the printing medium 16 (preferably ink) is transferred onto the printing surface 19 in the shape of a handprint 30 or footprint 31 . This handprint 30 and footprint 31 may then be copied onto a birth announcement 29 (shown in FIG. 14), a card, a mug, a shirt, a candy wrapper, or any other form of a personalized keepsake.
[0034] Alternatively, a user may insert a pre-printed keepsake birth certificate 27 (shown in FIGS. 1 and 2) between the imprint film 14 and the backer 22 of the impression medium. After pressing a hand 32 (shown in FIG. 3) or a foot 34 (shown in FIG. 5) onto the imprint film 14 , the printing medium 16 will be transferred directly onto the keepsake birth certificate 27 .
[0035] Although it is preferred that ink 17 (shown in FIG. 11) be the printing medium 16 used to record the handprint 30 or footprint 31 and that a type of paper product be the printing surface 19 , it should be understood that substantial benefit may be derived from an alternative embodiment of the impression medium 10 . For example, referring to FIGS. 8 - 10 , a bottom surface 33 (shown in FIG. 8) of a hand 32 (shown in FIGS. 8 - 9 (or alternatively a foot, not shown) can be first coated with a chemically reactive solution 18 . The coated hand 32 (or foot) can then be pressed onto chemically reactive paper 28 (shown in FIGS. 9 - 10 ). Finally, FIG. 10 shows the resulting handprint 30 that appears on the chemically reactive paper 28 .
[0036] Referring now to FIGS. 11 - 13 , an alternative method for preserving handprints and footprints is shown. A footprint 31 (or handprint) may also be recorded by first pressing a bottom surface 35 (shown in FIG. 12) of a foot 34 (or a hand) onto an inkpad 36 (shown in FIG. 11). The bottom surface 35 of the foot 34 (or hand) will then be coated with ink 17 (shown in FIG. 12). The foot 34 (or hand) is then pressed onto a printing surface 19 (shown in FIG. 13), such as cardstock 26 or artist board (not shown). FIG. 13 shows the resulting footprint 31 that appears on the cardstock 26 . The footprint 31 (or handprint) can then be copied, such as by photocopy or some other standard copying means, onto a birth announcement 29 (shown in FIG. 14) or some other personalized keepsake. If desired, the printing surface 19 may be sent by, for example, a parent or a guardian, to a manufacturer of various items as described above, who will place the handprint 30 or footprint 31 onto the items manufactured by the manufacturer for distribution to those people designated by the parent. | An impression medium for preserving handprints and footprints for reproduction. Preferably, the device is used for infants. Still further, preferably, the preserved handprints and footprints allow for reproduction onto personalized keepsakes, such as birth announcements, birth certificates, mugs, t-shirts, and candy wrappers. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to enlarging the diameter of a subterranean borehole, and more specifically to enlarging the borehole below a portion thereof which remains at a lesser diameter. The invention also is perceived to have general utility for drill bits.
2. State of the Art
It is known to employ both eccentric and bi-center bits to enlarge a borehole below a tight or undersized portion thereof.
An eccentric bit includes an extended or enlarged cutting portion which, when the bit is rotated about its axis, produces an enlarged borehole. An example of an eccentric bit is disclosed in U.S. Pat. No. 4,635,738.
A bi-center bit assembly employs two longitudinally-superimposed bit sections with laterally offset axes. The first axis is the center of the pass through diameter, that is, the diameter of the smallest borehole the bit will pass through. This axis may be referred to as the pass through axis. The second axis is the axis of the hole cut as the bit is rotated. This axis may be referred to as the drilling axis. There is usually a first, lower and smaller diameter pilot section employed to commence the drilling, and rotation of the bit is centered about the drilling axis as the second, upper and larger diameter main bit section engages the formation to enlarge the borehole, the rotational axis of the bit assembly rapidly transitioning from the pass through axis to the drilling axis when the full diameter, enlarged borehole is drilled.
Rather than employing a one-piece drilling structure ,.such as an eccentric bit or a bi-center bit to enlarge a borehole below a constricted or reduced-diameter segment, it is also known to employ an extended bottomhole assembly (extended bi-center assembly) with a pilot bit at the distal end thereof and a reatner assembly some distance above. This arrangement permits the use of any standard bit type, be it a rock bit or a drag bit, as the pilot bit, and the extended nature of the assembly permits greater flexibility when passing through tight spots in the borehole as well as the opportunity to effectively stabilize the pilot bit so that the pilot hole and the following reamer will traverse the path intended for the borehole. This aspect of an extended bottomhole assembly is particularly significant in directional drilling.
While all of the foregoing alternative approaches can be employed to enlarge a borehole below a reduced-diameter segment, the pilot bit with reamer assembly has proven to be the most effective overall. The assignee of the present invention has, to this end, designed as reaming structures so-called "reamer wings" in the very recent past, which reamer wings generally comprise a tubular body having a fishing neck with a threaded connection at the top thereof, and a tong die surface at the bottom thereof, also with a threaded connection. The upper mid-portion of the reamer wing includes one or more longitudinally-extending blades projecting generally radially outwardly from the tubular body, the outer edges of the blades carrying superabrasive (also termed superhard) cutting elements, commonly termed PDC'S (for Polycrystalline Diamond Compact). The lower mid-portion of the reamer wing may include a stabilizing pad having an arcuate exterior surface of the same or slightly smaller radius than the radius of the pilot hole on the exterior of the tubular body and longitudinally below the blades. The stabilizer pad is characteristically placed on the opposite side of the body with respect to the reamer blades so that the reamer wing will ride on the pad due to the resultant force vector generated by the cutting of the blade or blades as the enlarged borehole is cut. The aforementioned reamer wing as described and as depicted herein is not acknowledged or admitted to constitute prior art to the invention described and claimed herein.
While the above-described reamer wing design has enjoyed some success, the inventors herein have noted that cutting elements on the "leading" primary blade which contacts the formation suffer undue wear and in some instances damage in comparison to the other, following blades. This recognition and an appreciation of the phenomena leading to the aforementioned wear and damage have resulted in the present invention, which preserves and enhances the advantages of a state-of-the-art reamer wing while offering a more robust product to the industry.
SUMMARY OF THE INVENTION
The present invention comprises a reamer wing comprising a tubular body with at least two longitudinally-extending, unequally circumferentially-spaced blades carrying cutting elements thereon. The cutting elements are located in fight of the blade spacing for a given rate of penetration (ROP) and rotational speed of the reamer wing to provide a substantially equal workload between the cutting elements on all of the blades by adjusting the cutting depth of the cutting elements on one blade relative to that of the cutting elements on another blade.
More specifically, given ROP and rotational speed, the cutting elements on the leading blade of a blade series are adjusted upwardly or inwardly relative to the blade profile. Cutting element location may be adjusted as necessary or deskable on other blades as well, since three, four and even five-blade reamer wings are employed, the latter for particularly large boreholes. The adjustment is effected in most instances to substantially equalize the volume of formation material removed by cutting elements on each of the blades.
The invention also contemplates application to bit design in general, and particularly to multiple-bladed bits wherein the blades are not evenly circumferentially spaced. Such bits are quite common in practice, and notably include the recently-developed so-called "anti-whir" bits, wherein blades and cutting elements are placed to develop a directed lateral force vector and a cutting element-devoid bearing structure, typically a pad, is located on the gage in the area of the resultant lateral force vector.
The invention reduces the inequality in cutting element wear between a series of blades and the tendency of the leading blade and cuffing elements thereon in a blade series to sustain proportionally greater damage during drilling.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 through 3 comprise schematic partial sectional elevations of a bottomhole assembly including a reamer wing as employed in one aspect of the present invention, the bottomhole assembly being shown in pass through condition (FIG. 1), in start up condition (FIG. 2) and in a normal drilling mode for enlarging the borehole (FIG. 3);
FIG. 4 is a schematic bottom elevation of a three-blade reamer wing with blades set at the 0°, 45° and 90° circumferential positions;
FIG. 5 is a schematic depicting a cutter sequence for the three blades of the reamer wing of FIG. 4, with the cutters superimposed as if they were located at the same radius; and
FIG. 6 is a schematic showing partial profiles of the three blades of the reamer wing of FIG. 4 with identical cutter locations as in the prior art and exaggerated adjustments to cutter locations in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Commencing with FIG. 1 and moving from the top to the bottom of the assembly 10, one or more drill collars 12 are suspended from the distal end of a drill string extending to the rig floor at the surface. Pass through stabilizer (optional) 14 is secured to drill collar 12, stabilizer 14 being sized equal to or slightly smaller than the pass through diameter of the bottomhole assembly 10, Which may be defined as the smallest diameter borehole through which the assembly may move longitudinally. Another drill collar 16 (or other drill string element such as an MWD tool housing or pony collar) is secured to the bottom of stabilizer 14, below which reamer wing 100 according to the present invention is secured via tool joint 18, which may be a 6 5/8 inch API joint. Another API joint 22, for example a 4 1/2 inch API joint, is located at the bottom of the reamer wing 100. Upper pilot stabilizer 24, secured to reamer wing 100, is of an O.D. equal to or slightly smaller than that of the pilot bit 30 at the bottom of the assembly 10. Yet another, smaller diameter drill collar 26 is secured to the lower end of pilot stabilizer 24, followed by a lower pilot stabilizer 28 to which is secured pilot bit 30. Pilot bit 30 may be either a rotary drag bit or a tri-cone, so-called "rock bit". The bottomhole assembly as described is exemplary only, it being appreciated by those of ordinary skill in the art that many other assemblies and variations may be employed.
It should be noted that there is an upper lateral displacement 32 between the axis of pass through stabilizer 14 and that of reamer wing 100, which displacement is provided by the presence of drill collar 16 therebetween and which promotes passage of the assembly 10, and particularly the reamer wing 100, through a borehole segment of the design pass through diameter.
For purposes of discussion, the following exemplary dimensions may be helpful in understanding the relative sizing of the components of the assembly for a particular pass through diameter, pilot diameter and drill diameter. For a pass through diameter of 10.625 inches, a pilot diameter of 8.500 inches and a maximum drill diameter of 12.250 inches (the full bore diameter drilled by reamer wing 100) would normally be specified. In the bottomhole assembly 10, for the above parameters:
(a) drill collar 12 may be an eight inch drill collar;
(b) drill collar 16 may be a thirty foot, eight inch drill collar;
(c) drill collar 26 may be a fifteen foot, 6 3/4 inch drill collar; and
(d) pilot bit 30 may be an 8 1/2 inch bit.
In pass through condition, shown in FIG. 1, the assembly 10 is always in either tension or compression, depending upon the direction of travel, as shown by arrow 34 Contact of the assembly 10 with the borehole wall 50 is primarily through pass through stabilizer 14 and reamer wing 100. The assembly 10 is not normally rotated while in pass through condition.
FIG. 2 depicts the start-up condition of assembly 10, wherein assembly 10 is rotated by application of torque as shown by arrow 36 as weight-on-bit (WOB) is also applied to the string, as shown by arrow 38. As shown, pilot bit 30 has drilled ahead into the uncut formation to a depth approximating the position of upper pilot stabilizer 24, but reamer wing 100 has yet to commence enlarging the borehole to drill diameter. As shown at 32 and at 40, the axis of reamer wing 100 is laterally displaced from those of both pass through stabilizer 14 and upper pilot stabilizer 24. In this condition, the reamer wing 100 has not yet begun its transition from being centered about a pass through center line to its drilling mode center line which is aligned with that of pilot bit 30.
FIG. 3 depicts the normal drilling mode of bottomhole assembly 10, wherein torque 36 and WOB 38 are applied, and upper displacement 32 may remain as shown, but generally is eliminated under all but the most severe drilling conditions. Lower displacement 40 has been eliminated as reamer wing 100 is rotating about the same axis as pilot bit 30 in cutting the borehole to full drill diameter.
It may be seen that once normally drilling mode is reached, drilling proceeds, as far as the reamer wing blades are concerned, as with a normal drill bit. Thus, in this steady-state condition, it is desirable to equalize the work done by each of the blades by modifying the distribution of the depth of cut of the cutting elements on the various blades. Startup and transitional loading between start-up condition and normal drilling mode will always be complex and non-steady state, but the equalization of cutting loads among the blades according to the present invention will also better accommodate such transitional loading in a superior manner to state-of-the-art designs.
FIG. 4 is a schematic bottom elevation of an exemplary reamer wing 100 in accordance with the present invention including a tubular body 102 and three circumferentially-spaced blades 104, 106 and 108, looking upward from the bottom of the borehole. Blades 104, 106 and 108 would normally have the same or similar profile from reamer body 102 to the gage, or at least over a radial distance in which all would cooperatively cut with overlapping cutting element paths.
Blade 104, which is designated the "leading" blade with respect to the direction of rotation 110, may be said for the sake of convenience to be located at the 0° position of the 360° body circumference. Blade 104 would generally carry the radially innermost cutting element of all the blades, commonly designated the #1 cutter. Blades 106 and 108 are, respectively, set at the 45° and 90° positions, rotationally "behind" blade 104. Blade 106 would carry the #2 cutter, located at a slightly larger radius than cutter #1, while blade 108 would carry the #3 cutter, set at yet a slightly larger radius. Blade 104 would carry the #4 cutter (again a "leading" cutter), at a slightly larger radius than the #3 cutter on blade 108, and the sequence continued at least until gage diameter for the reamer wing 100 is reached. Such a spacing and cutter sequence would not be uncommon for the primary blades of a reamer wing.
On the opposite side of body 102 from blades 104, 106 and 108 and below the blades is an optional stabilizing pad 112 on the side of body 102 toward which the resultant lateral force vector of blades 104, 106 and 108 is directed during a reaming or hole-opening operation.
It is known that premature wear and damage of a reamer wing (and cutting elements) is not of substantial significance in softer formations wherein a high ROP such as 200-250 feet/hour is achievable. However, in harder formations where ROP may be at, for example, 30-120 feet/hour, premature wear and damage, particularly to PDC cutting elements and to cutting elements on a leading blade, may be significant.
In order to properly adjust the positions of the cutting; elements on the blades of reamer wing 100 to minimize adverse effects from the unequal spacing of blades 104, 106 and 108, it is desirable to select a realistic design ROP and a design rotational speed for the reamer wing to ascertain the depth of penetration of the formation per revolution. In this example, we select a 100 foot/hour ROP and a 120 revolution per minute rotational speed. Dividing 100 feet/hour by 120 revolutions per minute and correcting for units, we calculate the penetration per revolution as follows: ##EQU1##
Therefore, reamer wing 100 will penetrate the formation in question at approximately 0.167 in/rev.
Of the 0.167 in/rev. of penetration, given substantially identical cutting element locations, with respect to the blade profiles or with respect to an "exposure curve" on which lie the cutting edges of the cutting elements so that cutting element outer cutting edges are aligned on each of blades 104, 106 and 108, blade 104 will cut three-quarters of the penetration of 0.167 inches per each revolution, while blades 106 and 108 will each only cut one-eighth of the penetration. This is due to the fact that blade 104 cuts 270° of the 360° per revolution, or three-quarters of the penetration per revolution, while blades 106 and 108 cut a mere 45°, or one-eighth each, of the penetration per revolution. Given this observation, it is possible to adjust all of the cutting elements on a given blade "upward" or "downward" by the same distance with respect to the blade (or to adjust blade location itself) so that cutting elements on a trailing blade or blades take a relatively deeper cut into the formation and the leading blade cutting elements take a relatively shallower cut.
While cutting elements at the bottom of the blade may be adjusted in the "Z" direction or longitudinally, as one progresses up the side or flank of the blade away from body 102, an adjustment perpendicular to the blade profile is not necessarily a longitudinal adjustment, and so more generalized terminology has been employed.
It will also be appreciated that, rather than adjusting cutting element position, relative longitudinal blade position of the blades may be more easily altered to adjust cutting edge location, and that the lateral extent of the blade can be designed, along with longitudinal blade position, to provide the desired cutting element locations on one blade relative to those on another.
It will be appreciated that the leading cutting elements, those on blade 104, will be cutting a larger volume of formation material per revolution for identical cutter positions than those on blades 106 and 108. Therefore, by relatively "raising" the cutting elements on blade 104 to reduce their engagement with the formation, or "lowering" the cutting elements on blades 106 and 108 to increase their engagement depth, the volume of formation material cut by the cutting elements of blades 104, 106 and 108 can be substantially equalized. Given a rate of penetration per revolution of 0.167 inches, it can readily be seen that an "upward" movement of cutter #1 of 0.070 in. in combination with an "upward" movement of cutter #2 of 0.034 in. (cutter #3 remaining in its original design position) would balance the cutting action to substantially equalize cutter #1 's depth of cut with those of cutters #2 and #3 on the other two blades. Of course, the penetration per revolution would remain at. 0.167 in/rev., but the cutting work would be more equally balanced among the three cutters in question. The same design methodology can be applied to a second cutter sequence, and a third and additional, until gage diameter for the reamed borehole is reached. If all cutter sequences have started with the same relative cutter positions, the results from the first calculations can, of course, be applied to all of the sequences.
Referring to FIG. 5 of the drawings, the preceding explanation of relative cutting element position and its effect on work performed is illustrated in simplistic terms. FIG. 5 depicts cutters #1, #2 and #3 as they would be placed on blades 104, 106 and 108 but on the same radial position relative to a centerline CL. Showing a depth of cut (DOC) with respect to cutter #1, and assuming the same DOC for cutter #2 and cutter #3, it can readily be seen that cutter #1 cuts a far greater volume of formation material and is thus more susceptible to wear and damage than cutter #2 or cutter #3. Stated another way, cutter #1 removes formation material over the full DOC, while cutters #2 and #3 only remove formation material over their swaths or rotational paths to the extent it has not already been removed by cutter #1, due to the overlaps of the circular cutter paths as the reamer wing rotates.
Thus, while cutter #1 removes a half-circular cross-sectional path VOL 1 of formation material, cutter #2 and cutter #3 remove only a far smaller arcuate path, designated respectively as VOL 2 and VOL 3 on FIG. 5. The next cutter sequence, cutters #4, #5 and #6, repeats this pattern, with cutter #4 taking a disproportionate volume of cut.
Since, in reality, cutters #1-#3 are radially spaced and not on the same radius, the degree of overlaps is somewhat reduced but has nonetheless proven quite significant to relative cutting element wear and damage between blades.
FIG. 6 illustrates a blade edge segment for each of blades 104, 106 and 108 of reamer wing 100 placed one above the other and depicting cutters #1, #2, #3, #4, #5 and #6 as those six cutters might normally be spaced and placed on the blade edges if the blade provide were straight or flat. Also shown in broken lines are the same cutters adjusted in position to modify the depth of cut and substantially equalize the cutting work performed on the formation by three blades spaced as with reamer wing 100 of FIG. 4. While the figure and degree of movement is not to scale, it will be seen that the cutters of blade 104 are moved upward or inward with respect to their original positions, roughly twice the distance that the cutters of blade 106 are moved in the same direction. The cutters of blade 108 remain in the same location.
This same methodology may be employed to vary cutter location relative to profile in standard drill bits, and particularly those bits having blades with substantial inequalities in circumferential blade spacing, such as anti-whirl bits.
It is also contemplated that a reamer wing may be designed in accordance with the present invention to overaccommodate the design ROP. For example, one might design to an ROP of 150 feet/hour (creating a steeper helix angle) to provide extra protection while drilling through adjacent hard and soft formations or softer formations with stringers, wherein ROP might suddenly drop from 250 feet/hour to 100 feet/hour, so that the leading blade and cutters might better address this abrupt transition without damage.
While the invention has been described in terms of a preferred embodiment, it is not so limited, and many other additions, deletions and modifications may be effected thereto without departing from the scope of the invention as hereinafter claimed. | A multi-bladed reaming apparatus for enlarging a subterranean borehole, the apparatus having a tubular body with a plurality of longitudinally-extending, circumferentially-spaced, generally radially-extending blades carrying cutting elements, the blades being unequally spaced about the body. The cutting depth of the cutting elements on at least one of the blades is adjusted to modify the distribution of the depth of cut (DOC) among the cutting elements to substantially equalize the volume of formation material removed by the blades. Wear is reduced and the potential for premature failure of cutting elements on any single blade is alleviated. | 4 |
BACKGROUND OF THE INVENTION
The chemical industry uses steam taps and steam guns for saturated steam up to a maximum temperature of 200° C. However, there is also a need for water/steam mixing and an apparatus producing such a mixture from the individual components water and steam, which can then be applied by means of a gun. Such a water and steam mixture must have a temperature of 200° C. at the most. At higher temperatures than 200° C. there is a risk that the supply hoses will tear and that local overheatings or burning will occur.
It is therefore an object of the invention to provide a water and steam mixing device which ensures that the mixture never exceeds a given temperature, such as approximately 200° C.
SUMMARY OF THE INVENTION
This problem is solved by a device for the mixing of water and steam which is connected to a safety valve into which the supply lines for water and steam discharge and in which a valve is disposed which is actuated by the cooling water pressure and which interrupts the steam supply when the water supply is absent, wherein a casing has a cylindrical bore containing a positively inserted axially displaceable piston and which has, moulded-on or attached transversely of the axis of its bore, a spigot for steam and at an axial distance therefrom a further spigot for water, while the wall of the casing and a cylinder positively inserted in its bore are formed with openings on the steam side and openings on the water side which in the opening position are in alignment with openings in the piston on the steam side and openings in the piston on the water side and which do not register with one another in the closure position of the piston, the device also being characterized by a valve which is inserted coaxially and positively into an axial bore of the piston and can be axially displaced in relation thereto and whose head portion is subjected to the water pressure, its opposite end experiencing the pressure of a spring which when the water pressure is absent pushes the valve against an end stop into the closure position, in which the valve cuts off the flow of steam through the openings in the piston, while when the water pressure is present the valve is displaced against the force of the spring into the opening position, in which it allows the steam to flow through the piston openings, whereby the piston openings are so arranged that the water-to-steam mixing ratio can be changed. To this end more particularly the cross-sections of the openings for steam are larger than those in the supply spigot for steam, so that a further displacement of the piston beyond the actual opening position reduces the opening for water, while it remains unchanged on the steam side. As a result, the quantity of water is reduced with a constant quantity of steam.
The device according to the invention solves the problem underlying the invention, since when the water supply is interrupted--i.e., when there is a risk that the steam will not be cooled to below the given maximum temperature by the admixture of cold water--, the valve automatically cuts off the steam supply. The valve is therefore controlled by the water pressure. The valve is moved by the water pressure into its opening position, in which steam can enter the mixing chamber. However, if the water pressure drops, a return spring ensures that the valve automatically moves back into the closure position, in which the steam supply to the mixing vessel is interrupted.
A prefered embodiment of the device according to the invention forms a constructional unit comprising the device and the safety valve.
Also according to the invention in the opening position the valve interconnects by its central portion of reduced diameter the openings in the piston.
For the opening and closure of the water and steam supply lines, therefore, use is made of a piston which is axially displaceable in the casing and which is formed with separate openings for water and steam arranged in such a way that during the transition from the closure to the opening position, first it releases the opening for water and then the one for steam. Coaxially disposed in the piston is a valve which when its head surface is acted upon by water pressure can be axially displaced against the pressure of a return spring. The central portion of the valve is formed with a passage for water which in the opening position of the valve is in alignment with the opening in the piston for steam.
This construction according to the invention combines the advantages of a simple design with smooth operation, simple operability and reliable function, while more particularly it operates reliably when the water pressure falls.
The piston is disposed to be horizontally reciprocated by means of a handwheel or a motor in the casing in the cylinder inserted coaxially therein. Preferably the cylinder is axially fixed in the casing via the nipple for the supply of steam and/or cold water by the nipple engaging in a radial bore in the cylinder. This facilitates the assembly of the cylinder in the casing. Preferably the cylinder is secured against rotation by a pin. Basically the cylinder can be dispensed with if the casing bore takes the form of a cylinder.
The piston can be given an axial movement by a rotatable handwheel which cannot move axially. Alternatively, this can also be done by means of an electric motor which can be controlled by a temperature sensor measuring, for example, the water/steam mixing temperature. The mixing temperature can be controlled in this way; when the mixing temperature rises, the axial displacement in the piston in the cylinder triggered by the temperature sensor increases the water opening, thus increasing the water component of the water/steam mixture, so that the mixing temperature is again lowered to the required value. When the mixing temperature drops below the required value, the water opening in the casing is reduced by the axial displacement of the piston, so that the water component is reduced in relation to the steam component of the mixture, as a result of which the mixing temperature again rises to the required value.
In another preferred feature of the device according to the invention, downstream of the valve in the direction of flow a nozzle for steam is inserted in the casing portion moulded on the valve casing, with the formation of an annular space through which water flows. Another possible feature is that a mixing vessel receiving the water/steam mixture is provided which is flanged to the casing portion and has a spigot for the connection of the supply hose to the spraygun.
Preferably Viton sealing rings are inserted on the cold water side and Teflon sealing rings on the steam side.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in greater detail with reference to the embodiment thereof illustrated in the drawings, which show:
FIG. 1 is a longitudinal section through the device according to the invention in the valve closure position,
FIG. 2 is a longitudinal section of the valve casing to an enlarged scale in the opening position, and
FIG. 3 is a longitudinal section of the valve casing showing the piston in a position in which the water supply is throttled.
In the drawings like elements have like references.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in the general view in FIG. 1, the device according to the invention comprises a casing 1 into whose cylindrical cavity a mantle-type cylinder 2 is positively inserted and sealed off by sealing rings from the inner wall of the casing 1. Radially formed on the casing 1 are two axially spaced-out spigots 3 and 4, the former for the connection of a water line and the latter for the connection of a steam line. Inserted in the spigot 4 is a nipple 5 whose end portion engages in a radial bore 6 of corresponding size in the generated surface of the cylinder 2, thereby fixing the cylinder 2 axially in the casing 1.
A piston 7 is disposed positively and coaxially in the cylinder 1 and can be horizontally reciprocated therein by means of a handwheel 8. The end positions of the piston 7 are limited by a groove 10 with which the piston 7 is formed and in which a pin 9 inserted in the wall of the cylinder 2 engages by its portion extending beyond the inside wall of the cylinder 2. The length of the groove 10 thus corresponds to the path of travel of the piston 7 in the cylinder 2.
A valve 11 is mounted for axial displacement in the piston 7 coaxially with the casing 1, the cylinder 2 and the piston 7. The valve 11 has a widened head portion 12 which bears as a stop against a Seeger circlip ring is limiting its displacement to the right in the closure end position shown in FIG. 1. The valve 11 is forced to the right into this end position by a compression spring 14. The central portion 15 of the valve 11 is stepped with reduced diameter, with the formation of an annular gap 16 between said central portion 15 and the opposite wall of the piston 7.
The wall of the cylinder 2 is formed respectively with two diametrically opposite openings 17, 18 on the steam side and 19, 20 on the water side. Similarly, diametrically opposite openings 21, 22 on the steam side and 23, 24 on the water side are provided in pairs in the piston 7. The openings 21, 22 on the steam side in the piston 7 have a larger cross-section than the openings 17, 18 in the cylinder 2. The opening 23 in the piston 17 on the water side is larger than the opening 19 in the cylinder on the water supply side, while the water side openings 20, 24 in the piston 7 and the cylinder 2 have an identical size of cross-section on the water discharge side. The purpose of this dimensioning of the openings 17 to 24 will be further explained hereinafter.
The steam side opening 18 in the cylinder discharges into a widened expansion space 25 in casing portion 28, to which a nozzle 26 is attached which the steam passes through during its acceleration. An annular space 27 through which water flows is formed around the nozzle 26. The steam emerging at increased velocity from the nozzle entrains water from the annular space 27 and eddies therewith turbulently, with the formation of saturated steam. Flanged to the casing portion 28 containing the nozzle 26 is a mixing vessel 29 which has a nipple 30 for the connection of a spraygun hose.
The aforementioned parts of the device are sealed on the steam side by Viton rings, while Teflon sealing rings are inserted on the cold water side.
The casing 1 can be preferably made from cast aluminium, while the cylinder 2, piston 7 and valve 11 are made of special steel.
The water and steam mixing device according to the invention operates as follows:
FIG. 1 shows the device with the piston 7 in the closure position. In this position the piston 7 closes on the steam side both the opening 17 on the inlet side and also the opening 18 on the outlet side in the cylinder 2. On the water side the piston 7 has closed the water outlet opening 20 in the cylinder 2. Neither steam nor water can therefore flow through the casing 1.
To open the passages for water and steam, first shutoff members provided in the steam and water supply lines (not shown) are opened. As a result, steam passes through the nipple 5 as far as the closed opening 17 in the casing 1 and water passes via the spigot 3, the openings 19 in the cylinder 2 and the opening 23 in the piston 7 into the interior of the piston. The water pressure then acts on the head portion 12 of the valve 11 and produces a displacement of the valve 11 to the left as shown in the drawing against the pressure of the end side spring 14, until the central portion 15 of the valve 11 of reduced diameter is in alignment with the openings 21 and 22 of the piston 7 on the steam side. As a result, a passage is formed by the opening 21 with the annular space 16 around the central portion 15 of the valve 11 of reduced diameter and the opening 22. In this condition, however, the water and steam sides are still closed and the passage for both media through the valve casing 1 is blocked.
To now produce an opening of the passages, the piston 7 is gradually displaced by rotating the handwheel 8 out of the closure position shown in FIG. 1 in the axial direction in the fixed cylinder 2 and the casing 1 in the direction to the right as shown in the drawing into the opening position shown in FIG. 2. In that position, on the steam side the openings 17 are now in alignment via the passage 21, 16, 22 with the outlet opening 18, while on the water side the outlet openings 24 in the piston 7 are in alignment with the opening 20 in the cylinder 2. Now both steam and water can pass through the casing. The steam passes into the expansion space 25 in the casing portion 28, is accelerated in the nozzle 26 and entrains water from the surrounding annular space 14 into the mixing vessel 29, from which the saturated steam can then flow via the spigot 30 into the hose to the spraygun.
If now for any reason the water flow is absent, the water pressure inside the piston drops. Thereafter due to the absence of the water counter pressure the compression spring 14 can expand and pushes the valve 11 to the right as shown in the drawing as far as the stop formed by the Seeger circlip ring 13. During this movement the portion 31 of the valve 11 which adjoins the central portion 15 of reduced diameter is pushed over the openings 21 and 22 in the piston 7 as far as the full registration and separation thereof, as can again be seen in FIG. 1. The passage on the steam side is therefore blocked, although the openings 21 and 22 in the piston are still in alignment with the openings 17 and 18 in the cylinder 2. This ensures that steam can never pass through the valve casing when the water flow is absent. The valve 11 then automatically ensures the closure of the passage for steam through the casing 1.
If the mixture of water and steam is not hot enough, the piston 7 can be displaced beyond the opening position shown in FIG. 2 further to the left with reference to the drawing, into the end position shown in FIG. 3. In that position a passage cross-section for the steam has remained unchanged, while on the water side the quantity of water is reduced by the partial overlapping of the outlet openings 24 and 20 in the piston 7 and the cylinder 2 respectively. As a result the proportion of steam is increased correspondingly, the result being an increase in the temperature of the mixture of water and steam. | The invention relates to a device for the mixing of water and steam introduced via seperate closable supply lines into a mixing vessel wherein the water-to-steam ratio can be changed and wherein the steam supply can be automatically stopped if the water pressure drops below a given value. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention deals with a new type of wrapped thread and a process for its manufacture.
2. Description of the Prior Art
It is well known how to wrap threads. Schematically, this process consists of spirally winding a thread, called "covering" or "wrapping thread," around a second thread called "core thread." Depending on whether or not only one or several wrapping threads are used, it is described as a simple or a crossed wrapping. This technique of wrapping is very widely used in the fabrication of fancy threads and of elastic threads with an elastomeric core.
It is also known to use fragile threads, such as glass thread, threads of thermostable synthetic materials such as those made of aromatic polyamide, or threads of a refractory substance, with a cross directional sense of wrapping. In this case, the fragile thread forms the core, and the wrapping thread, advantageously made of synthetic thermoplastic material, is wound in a simple spiral (simple wrapping) in regular single and joined turns around the thread of the core which is kept in the shape of a straight line, whereby the wrapping thread protects the said core thread. Such a wrapped thread is described in the commonly assigned French Pat. No. 2,314,958, and it is used in the production of materials destined to reinforce plastic substances.
This latter technique, notably commercialized by L. Payen & Cie, still shows a certain number of inconveniences. Indeed, if, as is often the case, the core thread has a diameter which is greater than the diameter of the wrapping thread, the latter has the troublesome tendency to slip over the mentioned core. Therefore, the core thread is at once badly protected against abrasion from the outside, which means the abrasion suffered by the core thread with respect to another element, and equally badly against inside abrasion, which means the abrasion which is derived fromm the rubbings among the elemental fibers which form the core thread.
The present invention reduces these inconveniences. It deals with a new type of wrapped thread which has a very good resistance against abrasion from the outside as well as inside, and wherein the distinctive features of the core are practically unchanged by the presence of the thread of the outside wrapping.
Certainly, it is already known to make use of the phenomenon of gluing to modify the properties of thread-like textile elements. Thus, German Pat. No. DE-A 2,704,836 describes stringings, especially for supporting goods (tennis rackets) or musical instruments, where a core is covered by a binding liquid substance which dries immediately. Eventually, the core is covered by winding loose threads around it.
Moreover, it has been disclosed in the U.S. Pat. No. 3,644,866 to keep the parallel thread in position by means of a double-wrapped thread made in a loose manner. Before the wrapping, the core threads are bathed in a binding substance which ties them together.
The U.S. Pat. Nos. 2,313,058 and 2,424,743 both describe threads formed by the combination, via twisting, of two threads where one of them can be made adhesive by heat treatment. The heat treatment joins the fibers of the non-thermofusible thread together and improves the properties of the produced articles.
Likewise, the British Pat. No. 1,322,336 and the Luxemburg Pat. No. 66,345 describe the use of binding substances in order to modify the properties of textile materials.
Nevertheless, none of these disclosures provide wrapped threads having a very good resistance against abrasion from the outside as well as inside, and where the distinctive features of the core are practically unchanged by the presence of the outside wrapping thread, the latter being tied to the core by means of a very small quantity of heat sealing substance, where this substance does not modify the general distinctive features of the obtained thread.
SUMMARY OF THE INVENTION
In a general way, the invention deals with a new wrapped textile thread of the type which comprises a core consisting of threads which are appreciably parallel to one another, the mentioned core being covered by a wrapping thread which winds in a single turn forming a regular and joined spiral with at least one part of the peripheral surface of the core joined together by heat sealing with the wrapping thread. The textile thread is characterized by the fact that the binding of the core with the wrapping thread is obtained by fusion of a thread-like thermofusible element with a fusion temperature which is lower than the fusion temperature of the core and the wrapping.
In practice, in accordance with the invention, the weight of the thread thus obtained will comprise, with respect to the whole produced unit, at the most, ten percent (10%) heat sealing substance permitting the binding of the core with the wrapping thread, the latter representing, at the most, twenty-five percent (25%) of the produced unit.
Advantageously, in accordance with the invention, the multithreaded core composed of a plurality of individual threads, parallel or very slightly twisted, is made of fragile textile material, and is composed of, for example, glass threads, threads of a refractory material, such as carbon, boron, or silicon, or threads of an aromatic polyamide, such as the polymer of p-phenylene terephthalamide or similar ones like polyamide-imides, polyimides, etc. These substances have poor resistance to abrasion, outside as well as inside.
The wrapping thread around the core is a synthetic textile material of continuous threads, for example, polyester, polyamide 6--6, or polyamide 6.
If required, the core may be composed of an aggregation of several multithreaded and parallel subcores with very little torsion, on the order of a hundred (100) turns per meter.
The joining together of the core and the wrapping thread is achieved either by several separate thread-like elements spaced apart on the peripheral surface of said core, or by a spiral of joined or unjoined turns, preferably in the opposite direction to the spiral formed by the wrapping thread.
As a material which permits the joining together by thermofusion of the core with the wrapping thread, a thread-like material is used, which consists of, for example, a multifilament thread made of a thermofusible substance compatible at the same time with the kind of threads forming the core as well as with the kind of threads forming the wrapping thread. This thread-like material has a fusion temperature lower than the fusion temperature, and in practice also the degredation temperature, of the core thread and the wrapping thread.
A thread-like element which is particularly convenient for the implementation of the invention is composed of a threaded formed of a copolyamide 6 commercially sold under the name of GRILLON by the Grillon Company. The amount of this thread will be chosen in a way that the quantity which it represents in the formed unit does not exceed ten percent (10%) in weight.
A procedure for the manufacture of thread in accordance with the invention consists of winding in a known and simple way in joined and regular turns, a thread of the multifilament wrapping, preferably a synthetic thermoplastic material, around a core thread which consists of threads arranged almost parallel to each other. Between the core and the wrapping thread, there is provided at least one thread-like element made from a thermofusible substance with a fusion temperature which is less than the fusion temperature of the core and of the wrapping.
Then the unit made this way is thermally treated in order to achieve the fusion of the thread-like element and the joining together, by thermofusion, of the core with the wrapping thread. This thermal treatment can be achieved either continuously before winding on, or by a subsequent process.
According to one way of implementing the invention, one puts in at least one and preferably three thread-like elements, with the thread like elements being spaced apart at the periphery of the core. These threads are lined up parallel to the mentioned core before the winding, and are put between the wrapping thread and the core. In this way, after the thermal treatment, considerable joining together of the core and the wrapping thread is obtained by use of the thread-like elements. Such a technique is particularly economic and simple because it requires one single operation.
In an alternative procedure, prior to the winding of the wrapping thread, one makes a first winding, looose or with joined turns, by means of a thread-like thermofusible element. Preferably, this winding is carried out in the opposite direction of the final winding by the wrapping thread. After the thermal treatment, in this case, one obtains a joining by fusion of the core with the wrapping thread appreciably in the form of a spiral with joined or unjoined threads.
Finally, if the core is composed of a plurality of basic multithreaded subcores, it is possible to proceed either as previously shown, or by wrapping each of the basic subcores, for example by winding with a thermofusible thread. After the thermal treatment, a binding by heat sealing is obtained by binding the subcores among themselves, on the one hand, and by binding those subcores with the wrapping thread, on the other.
The way in which the invention can be carried out and the advantages which derive from it are better shown by the preferred embodiments, given as a guide but not restrictive, and which are illustrated by the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1, 2, and 3 represent summarily, in perspective, threads made according to the invention before the heat treatment permitting the heat sealing of the core with the outer wrapping thread.
FIG. 4 illustrates schematically, an installation which permits the production of a thread such as the one shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In a general way, according to the invention, the textile threads consist of a plurality of threads which are arranged substantially parallel to each other to form a core, and this core is covered by a wrapping thread, wound in a single turn to form a regular and joined spiral. In accordance with the invention, at least one part of the peripheral surface of the core is joined together by heat fusion with the wrapping thread.
In the example shown in FIG. 1, the wrapping thread 2 is joined together with core 1 by heat fusion by means of several thread-like elements 3 spaced apart on this core 1.
Such a thread can be produced by an installation such as that shown schematically in FIG. 4. In this manner of manufacture, core 1 is composed of five basic threads 11, joined with themselves without notable torsion, which means practically parallel. These threads come from a core 10, whereupon the bobbins of basic thread 11, are placed; then they pass through tighteners 12, for example, of a bar or rack type, and they are joined together by a convergence guide 13 in such a way as to form an aggregation, without appreciable torsion, of a plurality of threads composing core 1.
From spindle 14, kept continuously rotating, for example by a strap not shown, carrying a bobbin 15 of wrapping thread 2, said wrapping thread 2 is wound up in regular and joined turns around the formed core 1. This operation of winding is carried out in a conventional manner and will not be described in detail. The assemblage is made at the level of a guide 16, and then the wrapped thread is wound on a receiving bobbin in a classical manner by means of a guide 17 which goes back and forth on a receiving bobbin 18.
In accordance with the invention, one brings forward in parallel fashion, the thread-like elements 3 carried by the bobbins under the hollow spindle 14 before wrapping of the core thread 1 by the wrapping thread 2, and the thread-like elements 3 are spooled to the periphery of the formed core 1. These thread-like elements consist of a thread with a fusion temperature less than the fusion temperature of the wrapping thread 2 and the threads of core 1. These threads 3 are, therefore, surrounded and held by the wrapping thread 2. Before the winding on, or at a later stage, according to the invention, the formed thread is submitted to a heat treatment at a temperature which provokes the fusion of the thread-like elements 3 followed by the heat sealing of the core with the wrapping thread 2.
In the example shown in FIG. 2, the thermofusible thread-like element 6 is not arranged as separate thread-like elements spaced apart on the core but rather covers the core, for example, by the wrapping around of the core in joined or unjoined turns. This operation is carried out with the same material as that previously described. After this has been done, the final wrapping is carried out with the wrapping thread 5 in an equally conventional material. In this case, the two windings are carried out preferably in the opposite direction. After the thread has been made, it is likewise heat treated in a way to provoke the fusion of the thread-like element 6, thereby bringing about the binding of core 4 with the wrapping thread 5.
In the method of carrying out the invention which is shown by FIG. 3, core 7 is equally composed of the aggregation without appreciable torsion of five (5) basic subcores. Prior to their aggregation and to their wrapping by thread 8, these ends were wrapped individually by a thread-like element 9. The unit thus formed is likewise submitted to a heat treatment which provokes the fusion of the thread-like elements 9 and the heat sealing, on the one hand, of the basic subcores among themselves, and the sealing of these subcores with the wrapping thread 8, on the other.
EXAMPLE 1
With textile material for conventional wrapping such as that shown in FIG. 4, a thread is produced which is in accord with the invention, and which is pictured in FIG. 1.
This thread is composed of a core 1 of six (6) basic threads made of poly (p-phenylene terephthalamide), commercially sold by the E.I. DuPont de Nemours & Company under the trademark KEVLAR, with the individual fineness of 1,670 decitex, each basic thread composed of 1000 strands, not allowing any torsion, and a wrapping thread 2 composed of a polyester thread, 440 decitex, 100 strands, zero (0) torsion turn per meter. Prior to the wrapping, three (3) threads are formed, the three threads being composed of a copolyamide 6--6 of 220 decitex, 20 strands, commercially sold under the name GRILLON by the Grillon Company.
The winding of the wrapping thread 2 is done in such a way that the spiral turns formed around the core are regular and joined ones. This wrapping is made by 2000 turns per meter in an S direction.
The formed thread in which the GRILLON threads are firmly held between the core and the wrapping thread, is wound, and the formed bobbins are heat treated with steam at a temperature of one hundred five degrees Centigrade (105° C.) for thirty (30) minutes. This operation of heat treatment achieves the fusion of the three threads made of GRILLON and provokes the binding of core 1 with the thread of outside wrapping 2. This outside wrapping 2 is kept completely against core 1 and protects the threads which compose it against outside abrasion, and to a certain degree, equally against interior abrasion of the threads among themselves.
EXAMPLE 2
Example 1 is repeated with the variation that instead of incorporating three parallel GRILLON threads with the formed core thread 4 the core is covered beforehand by wrapping (as shown in FIG. 2) with a GRILLON thread 6 of 220 decitex, 20 strands, wound with 300 turns per meter around the core. This is done in the opposite direction of the external wrapping, i.e., in the Z direction in the present case.
After this thread has been made, an external wrapping 5 is produced in the same way as in Example 1, and with the same polyester thread.
As done before, the obtained thread is heat treated with steam at one hundred five degrees Centigrade (105° C.) for thirty (30) minutes, and the fusion of the GRILLON thread 6 would around core 4 is equally provoked. In this case, the binding of core 4 with the outside wrapping 5 is appreciably done in a spiral with practically joined turns.
The obtained thread also shows a very good resistance against outside abrasion, as well as an excellent protection against internal abrasion.
EXAMPLE 3
A thread a shown in FIG. 3 is produced.
This thread is composed of a core 7 formed by six (6) basicc subcores of a poly-(p-phenylene terephthalamide) commercially sold by the E.I. DuPont de Nemours & Company under the brand name KEVLAR with an individual fineness of 1,670 decitex, 1000 strands, without torsion.
Prior to the winding with the wrapping thread 8, each of these basic subcores is covered by a GRILLON 9 thread with the fineness 220 decitex, 20 strands, the winding being carried out by 2,150 turns per meter in the Z direction.
As in Example 1, five (5) of these basic wrapped threads are joined by using a wrapping thread 8, wound with joined turns, made of polyester of 400 decitex, 100 strands, the wrapping being carried out with 2,100 turns per meter in the S direction.
The threads thus produced are submitted to a heat treatment with steam of a duration of thirty (30) minutes at a temperature of one hundred and five degrees Centigrade (105° C.). This treatment achieves the melting of the GRILLON wrapping 9 and provokes the binding, on the one hand, of the basic subcores 7, among themselves, and on the other hand, the binding with the wrapping thread 8.
Such a thread provides, in comparison to the previously produced threads, a more improved protection of the outside surface, as well as improved protection against internal abrasion.
The threads which are obtained in accordance with the invention are essentially characterized by a substantial, if not total, decrease of the sliding of the wrapping thread about the core thread, and this is the case, if ever the latter has a considerably larger diameter than said wrapping thread. Furthermore, these threads retain all the properties of the core, given the small proportion of the wrapping thread and the material which permits the heat fusion. These threads can be successfully used in all applications called upon where the core thread is a fragile material. As examples, industrial fabrics, cables, straps, screens, etc., can be mentioned.
In another respect, given the fact that the material permits the binding of the core with the wrapping thread, the carrying ouf of the process of the present invention is particularly easy to achieve because of the presence of a thread-like binding element. Special material, such as a device for the binding material, is not necessary since this thread-like element can be directly built into the material which serves to produce the thread itself. | There is provided a new wrapped textile thread which includes a core made of threads arranged considerably parallel to each other. The core is covered by a wrapping thread which winds in a single turn, forming a regular and joined spiral around the core. This textile thread is characterized by the fact that at least one part of the peripheral surface of the core is joined together by heat sealing with the wrapping of winding thread. The textile thread is useful in textile materials which require a very good resistance against abrasion. | 3 |
This is a continuation of application Ser. No. 08/156,527 filed Dec. 13, 1993, now abandoned, which is a Continuation of application Ser. No. 07/827,647 filed Jan. 29, 1992, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a process for preparing microcapsules having a wall membrane made of a polyurethane urea resin. More particularly, the present invention relates to a process for preparing microcapsules having a uniform distribution of particle size.
Various processes for producing microcapsules have been known, including the coacervation process, the interfacial polymerization process and the in-situ process. Microcapsules prepared by these processes are widely used in various fields such as medicine, pesticides, dyes, adhesives, liquid fuels, perfumes and liquid crystals.
In these microcapsules, the particle size is an important factor that determines their quality. It is considered desirable to prepare microcapsules having a uniform particle size. In the case of microcapsules used for pressure-sensitive recording sheets, in general, the more uniform the particle size distribution, the better the coloring properties and pressure resistance of the sheet. The reason for this is considered to relate to the fact that microcapsules having considerably smaller particle sizes than the average value do not break upon coloring and thus do not contribute to coloring, while those having too great particle sizes are apt to rupture and thus easily cause so-called pressure fogging.
Thus, it has been important to obtain microcapsules with a desired particle size and a narrow particle size distribution in order to produce excellent pressure-sensitive recording sheets.
For this purpose, there has been proposed a process involving mixing an oily solution and an aqueous solution, pumping the resulting mixed solution through a cylindrical member in which is disposed a static liquid shearing device or a liquid shearing device which moves under the action of the passing solution to form an oil-in-water type emulsion, and then forming a wall membrane thereon to prepare microcapsules. Such a process is disclosed in JP-A-57-84740 (the term "JP-A" as used herein means an "Unexamined Published Japanese Patent Application"). There has also been proposed a process for the preparation of urea-formalin or melamine-formalin resin capsules which includes steps of mixing an oily solution and an aqueous solution, pumping the resulting mixed solution into a spindle through introduction pores opening tangentially at the center thereof while the solution is spirally rotated so that the solution reaches injection pores opening at both ends thereof to form an oil-in-water type emulsion, and then forming a wall membrane thereon to prepare microcapsules. This type of process is disclosed in JP-A-59-87036.
However, none of these processes can provide a particle size distribution sufficiently narrow to drastically improve the properties of the microcapsules since the shearing force acting on the emulsion is nonuniform in the emulsification process (where the particle size of microcapsules is determined). Thus, the particle size distribution can be narrowed only to some limited extent using these processes.
In another example of a known process, an emulsifying device such as a high-shear agitator, a homogenizer or an in-line mixer is used. However, this process can provide only an emulsion with a broad particle size distribution since the region on which the shearing force necessary for emulsification acts is limited to regions very near the emulsification blade, and the shearing force is nonuniform over the distance to the emulsification blade.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a process for the preparation of microcapsules with a uniform particle size distribution by a simple mechanism to solve these problems.
The above and other objects of the present invention have been accomplished by a process for the preparation of microcapsules having a wall membrane made of a polyurethane urea resin, which process comprises mixing an oily solution and an aqueous solution, passing the resulting mixed solution through a clearance between an inner cylinder and an outer cylinder which are rotated relative to each other to thereby form an oil-in-water type emulsion, and then forming a wall membrane thereon.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram illustrating an apparatus used in the practice of a preferred embodiment of a process of the present invention;
FIG. 2 is a schematic view of a system in which a continuous procedure begins with preemulsification;
FIG. 3 is a schematic view of a system in which a large amount of material is effected; and
FIGS. 4 and 5 are graphs illustrating the particle size distribution and cumulative volume distribution in an example of the invention and in a comparative example, as determined by a Coulter counter (Coulter Electronics, Type TA-II).
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The advantage of the emulsification process of the present invention is that, unlike the prior art emulsification process in which a nonuniform shearing force acts on an emulsion, it always provides a uniform shearing force on the emulsion. In accordance with the emulsification process of the present invention, microcapsules with a desired particle size and a narrow particle size distribution can be obtained.
The inventive process for the preparation of microcapsules will be outlined with reference to the embodiment shown in FIG. 1.
Referring to FIG. 1, an oily solution and an aqueous solution are mixed in a proper proportion in a preemulsifying tank 1 by stirring by an agitator 6 to prepare a preemulsion. The preemulsion is then pumped by a pump 2 into an outer cylinder 3 through a solution introduction port 13a mounted thereon. The outer cylinder 3 contains an inner cylinder 4 which is rotated by a motor 5. Once fed into the outer cylinder 3, the solution then moves toward a solution discharge port 13b while receiving a uniform shearing force between the outer cylinder 3 and the inner cylinder 4. The solution is then fed through the discharge port 13b to a capsulization tank 7 where it is subjected to wall membrane formation to obtain microcapsules.
In the present invention, the formation of an oil-in-water type emulsion can be accomplished by the use of an emulsifying apparatus including an inner cylinder 4 and an outer cylinder 3 which are rotated relative to each other.
In the inventive emulsifying apparatus, the clearance between the inner cylinder 4 and the outer cylinder 3 is not specifically limited, but is preferably in the range of 0.05 to 5 mm, more preferably 0.1 to 2 mm.
If the clearance falls below the above-specified range, the effects of the surface finish of the inner cylinder and outer cylinder and the deflection of the inner cylinder in the clearance become great, resulting in a nonuniform clearance distribution, and hence a nonuniform shearing force distribution, and hence a broader particle size distribution. Further, under this situation, the inner cylinder can come into contact with the outer cylinder, causing failure after prolonged use.
On the contrary, if the clearance exceeds the above-specified range, the rate of rotation of the inner cylinder must be increased to obtain a shearing force strong enough to provide a desired particle size. However, finely divided particles are produced in the vicinity of the inner cylinder, causing a wide particle size distribution.
The retention time of the emulsion in the clearance portion is in the range of 0.02 seconds, or more preferably 0.2 seconds or more. If the value falls below this range, a phenomenon called "short path" occurs, whereby coarse grains are formed that widen the particle size distribution.
The structure of the emulsifying apparatus of the present invention is not limited to that shown in FIG. 1.
The main feature of the dispersion process of the present invention is that emulsification occurs in the clearance between an inner cylinder and an outer cylinder which are rotated relative to each other. The inner and outer cylinders are preferably in the form of column. In other words, it is essential that the clearance between the inner cylinder and the outer cylinder be held constant to cause a uniform shearing force to act on the emulsion. In accordance with the process of the present invention, an emulsion with a desired particle size can be obtained at a single pass, and continuous production of such an emulsion is made possible.
FIG. 2 illustrates an embodiment in which an oily solution 9 and an aqueous solution 8 are continuously fed to a continuous preemulsifier 10 where a continuous procedure begins with preemulsification. In accordance with this process also microcapsules with a desired particle size and a uniform particle size distribution can be obtained.
FIG. 3 illustrates an embodiment in which three units of the emulsifiers used in the present invention are connected to raise the production efficiency. In accordance with this process, a large amount of material can be processed in a compact equipment, and microcapsules with a desired particle size and a uniform particle size distribution can be obtained. Reference numeral 11 renotes a pulley and reference numeral 12 renotes a distributing valve.
As mentioned above, in accordance with the emulsification process of the present invention, an invariably uniform shearing force can be applied to the solution, and an emulsion with a desired particle size and a uniform particle size distribution can be formed. The emulsion can be then subjected to wall membrane formation to produce microcapsules with a desired particle size and a narrow particle size distribution.
The present invention will be further described in the following examples, but the present invention should not be construed as being limited thereto. The present invention can also be applied to microcapsules for use in medicine, pesticides, dyes, adhesives, liquid fuels, perfumes, liquid crystals, etc.
EXAMPLE 1
As color developers, 100 gm of crystal-violet lactone, 10 gm of benzoyl leucomethylene blue, and 40 gm of 3-[4-(dimethylamine)-2-ethoxyphenyl]-3-(2-methyl-1-ethyl-3-indolyl)-4-azaphthalide were dissolved in 2,000 gm of diisopropyl naphthalene.
In the oily solution thus obtained were dissolved 160 gm of a carbodiimide-modified diphenylmethane diisocyanate (Millionate MTL available from Nihon Polyurethane K.K.) 160 gm of a biuret compound of hexamethylene diisocyanate (Sumidule N-3200 available from Sumitomo Bayer Urethane K.K.) as polyvalent isocyanates, and 64 gm of a butylene oxide adduct of ethylene diamine (added amount of butylene oxide per ethylene diamine: 16.8 mol; molecular weight: 1,267) as alkyl oxide adduct of amine to prepare an oily solution. 300 gm of a polyvinyl alcohol was dissolved in 2,700 gm of water to prepare an aqueous solution.
The oily solution was then poured into the aqueous solution while the latter was stirred at 800 rpm using a propeller agitator with a blade diameter of 70 mm to prepare an oil-in-water type emulsion as preemulsion.
The preemulsion was then processed at a single pass in the apparatus as shown in FIG. 1 at a flow rate of 1 kg/min and at a rotational speed of 1,500 rpm with the clearance between the inner cylinder and the outer cylinder set to 300 μm to obtain an emulsion. To the emulsion was added 2,000 gm of water with a temperature of 20° C. The system was heated to a temperature of 65° C. where it was held for 90 minutes to obtain a capsule solution.
These capsules were then measured for particle size distribution using a Coulter counter Type TA-II. As shown in FIG. 4, the specimen exhibited an extremely high uniformity in particle size distribution (D50=6.5 μm; D90/D10=1.69).
To the capsule solution thus obtained were added 2,000 gm of a 15% aqueous solution of a polyvinyl alcohol, 600 gm of a carboxy-modified SBR latex in the form of solid, and 1,200 gm of a particulate starch (average particle size: 15 μm). Water was then added to the system so that the solid concentration was adjusted to 20% to prepare a coating solution.
The coating solution thus obtained was coated on a paper with a density of 40 gm/m 2 in such an amount that the dried weight reached 4.0 gm/m 2 , and then dried to prepare a microcapsule sheet.
EXAMPLE 2
A microcapsule sheet was prepared in the same manner as in Example 1, except that the preemulsion was processed at a single pass in the apparatus shown in FIG. 1 at a flow rate of 3 kg/min and a rotational speed of 2,000 rpm, with the clearance between the inner cylinder and the outer cylinder set to 500 μm.
The capsule specimen was measured for particle size distribution. It was found that the specimen exhibited an extremely high uniformity in particle size distribution (D50=7.8 μm; D90/D10=1.70).
Comparative Example 1
The same oily solution as used in Example 1 was poured into the same aqueous solution as used in Example 1 while the latter was stirred at 2,000 rpm by a dissolver with a blade diameter of 100 mm. The agitation lasted for one minute. Thus, an oil-in-water type emulsion was formed.
To the emulsion was added 2,000 gm of water with a temperature of 20° C. The system was gradually heated to a temperature of 65° C. where it was held for 90 minutes to obtain a capsule solution.
The capsule solution was then measured for particle size distribution using a Coulter counter Type TA-II. As shown in FIG. 5, the capsule specimen exhibited a wide particle size distribution (D50=6.7 μm; D90/D10=3.0).
To the capsule solution thus obtained were added 2,000 gm of a 15% aqueous solution of a polyvinyl alcohol, 600 gm of a carboxy-modified SBR latex in the form of solid, and 1,200 gm of a particulate starch (average particle size: 15 μm).
Water was then added to the system so that the solid concentration was adjusted to 20% to prepare a coating solution.
The coating solution thus obtained was coated on a paper sheet with a density of 40 gm/m 2 in such an amount that the dried weight thereof reached 4.0 gm/m 2 , and then dried to prepare a microcapsule sheet.
Comparative Example 2
The same oily solution as used in Example 1 was poured into the same aqueous solution as used in Example 1 while the latter was stirred at 1,500 rpm by a dissolver with a blade diameter of 100 mm. The agitation lasted for one minute. Thus, an oil-in-water type emulsion was formed. To the emulsion was added 2,000 gm of water at a temperature of 20° C. The system was gradually heated to a temperature of 65° C. where it was held for 90 minutes to obtain a capsule solution.
The capsule solution was then measured for particle size distribution using a Coulter counter Type TA-II. The capsule specimen exhibited a wide particle size distribution (D50=7.9 μm; D90/D10=4.3).
To the capsule solution thus obtained were added 2,000 gm of a 15% aqueous solution of a polyvinyl alcohol, 600 gm of a carboxy-modified SBR latex in solid form, and 1,200 gm of a particulate starch (average particle size: 15 μm).
Water was then added to the system so that the solid concentration was adjusted to 20% to prepare a coating solution.
The coating solution thus obtained was coated on a paper sheet with a density of 40 gm/m 2 in such an amount that the dried weight thereof reached 4.0 gm/m 2 , and then dried to prepare a microcapsule sheet.
EXAMPLE 3
As color developers, 120 gm of 2-anilino-3-methyl-6-N-ethyl-N-isopentylaminofluorane and 20 gm of 2-dibenzylamino-6-diethylaminofluorofurane were dissolved in 2,000 gm of 1-phenyl-1-xylyethane. In the oily solution thus obtained were dissolved 160 gm of a carbodiimide-modified diphenylmethane diisocyanate (Millionate MTL available from Nihon Polyurethane K.K.) and 160 gm of a biuret compound of hexamethylene diisocyanate (Sumidule N-3200 available from Sumitomo Bayer Urethane K.K.) as polyvalent isocyanates, and 64 gm of a butylene oxide adduct of ethylene diamine (added amount of butylene oxide per o ethylene diamine: 16.8 mol; molecular weight: 1,267) as alkyl oxide adduct of amine to prepare an oily solution.
300 gm of a polyvinyl alcohol was dissolved in 2,700 gm of water to prepare an aqueous solution. The oily solution was then poured into the aqueous solution while the latter was stirred at 800 rpm using a propeller agitator with a blade diameter of 70 mm to prepare an oil-in-water type emulsion as preemulsion.
The preemulsion was then processed at a single pass in the apparatus as shown in FIG. 1 at a flow rate of 1 kg/min and 1,500 rpm with the clearance between the inner cylinder and the outer cylinder set to 300 μm to obtain an emulsion. To the emulsion was added 2,000 gm of water at a temperature of 20° C. and 7.2 gm of diethylene triamine as polyvalent amine. The system was stirred at room temperature for 10 minutes, and heated to a temperature of 65° C. where it was held for 60 minutes to obtain a capsule solution.
The capsule specimen was then measured for particle size distribution using a Coulter counter Type TA-II. The specimen exhibited an extremely high uniformity in particle size distribution (D50=7.0 μm; D90/D10=1.70).
To the capsule solution thus obtained were added 1,600 gm of a 15% aqueous solution of a polyvinyl alcohol, 400 gm of a carboxy-modified SBR latex in the form of solid, and 1,000 gm of a particulate starch (average particle size: 15 μm).
Water was then added to the system so that the solid concentration was adjusted to 20% to prepare a coating solution. The coating solution thus obtained was coated on a paper sheet in such an amount that the dried weight thereof reached 4.0 gm/m 2 , and then dried to prepare a microcapsule sheet.
Comparative Example 3
The same oily solution as used in Example 3 was poured into the same aqueous solution as used in Example 3 while the latter was stirred at 2,000 rpm by a dissolver with a blade diameter of 100 mm. The agitation lasted for 1 minute. Thus, an oil-in-water type emulsion was formed.
To the emulsion was added 2,000 gm of water with a temperature of 20° C. and 7.2 gm of diethylene triamine as polyvalent amine. The system was stirred at room temperature for 10 minutes, and then gradually heated to a temperature of 65° C. where it was held for 60 minutes to obtain a capsule solution.
The capsule solution was then measured for particle size distribution using a Coulter counter Type TA-II. The capsule specimen exhibited a wide particle size distribution (D50=7.1 μm; D90/D10=3.3).
To the capsule solution thus obtained were added 1,600 gm of a 15% aqueous solution of a polyvinyl alcohol, 400 gm of a carboxy-modified SBR latex in the form of solid, and 1,000 gm of a particulate starch (average particle size: 15 μm).
Water was then added to the system so that the solid concentration was adjusted to 20% to prepare a coating solution.
The coating solution thus obtained was coated on a paper sheet with a density of 40 gm/m 2 in such an amount that the dried weight thereof reached 4.0 gm/m 2 , and then dried to prepare a microcapsule sheet.
For the evaluation of properties, these microcapsule sheets were each combined with a developer sheet to prepare pressure-sensitive recording sheets. The results are set forth in Table 1. The evaluation tests were carried out as follows:
1) Test for coloring properties
Microcapsule sheets prepared as discussed above were each laminated with a developer sheet. Onto these laminates were continuously typed a lowercase letter "m" using an electronic typewriter (IBM model 6747), and the typed letters were then colored. After one day, the specimens were measured for type density D (typewriter) in the visible range by a Macbeth RD-918 type densitometer.
2) Test for pressure resistance
These microcapsule sheets were each laminated with a developer sheet. These laminates were each subjected to a load of 10 kg/cm 2 so that the developer sheet was fogged.
These laminate specimens were aged for three days, and then measured for fog density D (fog) on the developer sheet at 610 nm using a Type 307 Hitachi Color Analyzer.
The results of these tests are set forth in Table 1.
TABLE 1__________________________________________________________________________ Comparative Comparative Comparative Example 1 Example 2 Example 3 Example 1 Example 2 Example 3__________________________________________________________________________1) Particle 6.5 7.8 7.0 6.7 7.9 7.1size (D50)μm2) Particle 1.69 1.70 1.70 3.0 4.4 3.3sizedistribution(D90/D10)3) Coloring 0.50 0.53 0.49 0.45 0.49 0.43properties(typewriter)4) Pressure 0.077 0.082 0.078 0.102 0.121 0.098resistance D(fog)__________________________________________________________________________
As shown in Table 1, as compared to the comparative microcapsule sheets, the microcapsule sheets of the present invention exhibited quite excellent properties, i.e., excellent coloring properties and pressure resistance.
In Table 1, D10, D50 and D90 are percentage particle sizes determined from cumulative volume distribution.
In other words,
D10: cumulative 10% particle size,
D50: cumulative 50% particle size, and
D90: cumulative 90% particle size.
When an emulsifying apparatus according to the present invention is used, a uniform shearing force can be applied to the emulsion, which is not possible with prior art emulsifying apparatus such as dissolver. Therefore, an emulsion with a small particle size and a uniform particle size distribution can be produced. Microcapsules prepared from this emulsion exhibit a small particle size and a uniform particle size distribution. For example, if these microcapsules are used for pressure-sensitive recording sheets, the resulting pressure-sensitive recording sheets exhibit excellent coloring properties as well as excellent pressure resistance.
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. | A process for the preparation of microcapsules having a wall membrane made of a polyurethane urea resin, which includes steps of mixing an oily solution and an aqueous solution, passing the resulting mixed solution through a clearance between an inner cylinder and an outer cylinder which are rotated relative to each other to form an oil-in-water type emulsion, and then forming a wall membrane on droplets of the resulting emulsion. In a preferred embodiment, the clearance between the inner cylinder and the outer cylinder is preferably in the range of 0.05 to 5 mm, more preferably 0.1 to 2 mm. The retention time of the emulsion in the clearance portion is in the range of 0.02 seconds or more, preferably 0.2 seconds or more. The inner and outer cylinders are in the form of column, optionally conical in part thereof. | 1 |
BRIEF DESCRIPTION OF THE INVENTION
This invention relates to apparatus for regulating vehicular traffic. It is specifically concerned with collapsible barriers which control vehicular access to parking areas and transitways.
The inherent dangers associated with the operation of motor vehicles make it particularly desirable to limit their access into certain areas. Barriers are therefore commonly used to obstruct the flow of traffic into areas such as pathways, roads, parking areas, and open other spaces which are physically accessible to vehicles, and yet vulnerable to the damage they cause.
Permanent barriers for blocking access to all vehicles are effective to protect areas which are only intended to serve pedestrians. Permanent barriers may also be made up of elements spaced apart from one another in order to obstruct large vehicles such as trucks, but to allow access by smaller vehicles. This provides adequate protection for areas which are not subject to damage by automobiles and motorcycles.
Removable barriers provide flexible access by obstructing vehicles at certain times, while allowing passage at other times. Removable barriers are particularly useful where emergency vehicles which must be admitted into areas that are normally blocked off to traffic. For example, universities, apartment complexes, libraries, corporate centers, and other facilities frequently protect pedestrians and property by prohibiting vehicles from being driven off of roads and driveways. Removable barriers allow emergency police, medical, and fire department vehicles access to areas thus protected.
Flexible vehicular access restriction is also used to prevent the public from parking in reserved parking areas. Removable barriers are particularly effective for doctors who require special parking at hospitals, officials at public buildings, and athletes at sporting events.
The need for flexible barrier systems to control vehicular access has led to a number of different kinds of barriers. Locked gates have long been used for obstructing vehicles of all types. Gates, however, also obstruct pedestrian traffic, and locks securing the gates are often exposed to the elements and become inoperable over time. The use of keys or combinations further encumbers emergency access, which at best slows down emergency personnel, and at worst bars their access.
U.S. Pat. No. 5,018,902, to Miller et al., describes a bollard which is hinged so that it can fold into a collapsed position. Inside the bollard, a latch bar mates with a protruding locking section rigidly connected to a base, to lock the bollard in an upright, obstructing position. A fireplug wrench is used to actuate the latch bar to disengage it from the locking section, by swinging it about an axis perpendicular to the hinge axis. For automatic reengagement, a hinge is provided in the latch bar, and the portion of the latch bar below the hinge is spring-urged so that it snaps into engagement with the locking section when the bollard housing is brought to its upright, obstructing position. The latch bar needs to be quite large so that a relatively small amount of rotation of the fireplug wrench produces enough movement of a remote portion of the latch base to clear the protruding locking section connected to the base. Consequently, a large movement is required to disengage the latch bar from the locking section. The force needed to disengage the latch bar from the locking section may increase over time as a result of corrosion, and consequently, release of the bollard may become increasingly difficult and failure may occur eventually.
U.S. Pat. Nos. 4,576,508 and 4,715,742, to Dickinson, describe bollards which are vertically depressible into underground mounting frames. The locking mechanisms of these bollards may, however, become exposed to the elements, causing them to freeze in position. These bollards are also expensive to install and dependent upon complex actuation mechanisms.
U.S. Pat. No. 4,919,563, to Stice, describes a vertically depressible bollard with a substantially self-contained actuation mechanism. This bollard is exceedingly complex, and is dependent upon an electrical power source, which is supplied either through an enclosed battery, or through wires from an outside power source.
The principal object of this invention is to provide a barrier to vehicular access which may be quickly and easily collapsed into a non-obstructing position. Another object of this invention is to provide a vehicular barrier with a simple, strong, durable, and reliable mechanism, which can be easily moved between the collapsed and obstructing positions, without the need for an electric or hydraulic power source. A further object of this invention is to provide a collapsible barrier to vehicular traffic which is simple and inexpensive to manufacture and to install.
In accordance with the invention, the collapsible barrier is installed to control the ingress and egress of vehicles into otherwise accessible areas. The barrier may be locked in an obstructing position, and may be manually collapsed to allow vehicles to pass.
The collapsible barrier in accordance with the invention comprises a base rigidly secured to the floor of the space into which it is installed. An elongated post, which obstructs vehicular access when vertically disposed, is connected to the base by a post hinge. The post hinge permits the post to swing about a post hinge axis between the obstructing and collapsed positions.
A first latch member is fixed to the base and engages a second latch member at a location lateral to the post hinge axis, thereby securing the post in the obstructing position. The second latch member is connected to the post by a second hinge providing an axis of rotation parallel to, and laterally spaced from, the post hinge axis. This allows the second latch member to rotate into and out of engagement with the first latch member. A manually operated actuator, accessible from the exterior of the post, effects this swinging movement of the second latch member about the second hinge axis, in a direction to disengage the second latch member from the first latch member.
A spring, connected to the post and to the second latch member, urges the second latch member in a direction to engage the first latch member. The first and second latch members have mutually engaging camming surfaces which effect swinging movement of the second latch member about the second hinge axis. This allows the first and second latch members to re-engage each other automatically when the post is moved into the obstructing position.
The collapsible barrier in accordance with the invention provides an effective barrier to vehicular access which may be swiftly collapsed into a non-obstructing position. The use of second latch member hinged to the post on a hinge axis parallel to the post hinge axis, allows the latch member to be disengaged easily from each other. Preferably, the second latch member is engaged by a separate actuating element so that it can move independently of the separate actuating element. This reduces the force required to move the second latch member during reengagement of the latch members, while making disengagement of the latch members easy.
This actuating mechanism is strong, reliable, durable, and easy to operate, and the collapsible barrier is inexpensive to manufacture and to install.
Further objects, details and advantages of the invention will be apparent from the following detailed description, when read in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially broken-away elevational view of a collapsible barrier in accordance with the invention, with its post disposed in the obstructing position;
FIG. 2 is a partially broken-away elevational view of a collapsible barrier with the post disposed midway between its obstructing and collapsed positions;
FIG. 3 is a sectional view of the collapsible barrier, taken on plane 3--3 of FIG. 1, showing the manually operated latch actuation assembly.
DETAILED DESCRIPTION
The collapsible barrier 1 shown in FIGS. 1, 2, and 3 comprises a base 2 firmly anchored to the floor 4 of the installation site. The base is preferably in the form of a thick-walled metal tube of rectangular cross-section. The base 2 is preferably embedded in a below grade concrete foundation 6.
An elongated post 8, which is also preferably in the form of a thick-walled metal tube having a rectangular cross-section, is connected to the base 2 by a post hinge 10, as shown in FIGS. 1 and 2. The hinge 10 is preferably located just above grade level. The post 8 rests on top of the base 2 so that the bottom edges 12 and 14 of the post are aligned with the top edges 16 and 18 of the base. The contiguous connection between the post 8 and base 2 is formed near floor level.
The post hinge 10 permits the post to swing about a horizontal post hinge axis, which is located adjacent to the connection between bottom portion 14 and top portion 18. The post 8 can therefore swing from the vertical position shown in FIG. 1, through the intermediate position shown in FIG. 2, to a substantially horizontal, collapsed condition in which it rests on floor 4.
In its collapsed condition, the post 8 allows vehicles to pass. Conversely, the post 8 physically obstructs vehicular access when disposed in an upright position with its direction of elongation substantially vertical as shown in FIG. 1. It is preferred that the post 8 be manufactured from stainless steel or other material with high impact and tensile strengths so that it is capable of sustaining light impacts without deformation, and remaining upright when subjected to heavier forces.
A first latch member 20 is rigidly welded to an inner wall of the base 2 at a location laterally spaced from the post hinge 10.
The first latch member 20 is composed of two sections, a lower section 22 and an upper section 24. The lower section 22 extends parallel to the direction of elongation of the post 8 in the obstructing position. The upper section 24 overhangs the lower section 22, and extends into the interior of the post 8. The bottom of the overhanging portion, which forms a latching surface, is flat. The upper side of the overhanging portion extending has a convex curvature forming a camming surface.
The portion of the base 2 connected to the first latch member 20 extends vertically above the floor to a height equal to that of the first latch member 20. This shields the first latch member 20 from impact when the post 8 is in the collapsed position. The post therefore meets the base at a location closer to the ground on the post hinge side, than on the opposite side.
A second latch member 26 is connected to the post 8 by a second hinge 28, which is mounted on an interior wall of the post by a plate 44, welded to the post. The second latch member 26 has an upper section 30 and a lower section 32. The upper section 30 is completely housed within the post 8. The lower section 32 is shaped similarly to the first latch member 20, having a flat upper surface for engaging the flat surface of section 24, and a convex camming surface on its lower side for engaging the camming surface of section 24.
The second latch member 26 is positioned on the second hinge 28 so that the overhanging portions of both latch members 20 and 26 engage each other when the post 8 is in the obstructing position. This engagement prevents the post 8 from rotating about the post hinge axis.
The second hinge 28 allows the second latch member 26 to rotate into and out of engagement with the first latch member 20 by providing an axis of rotation parallel to, and laterally spaced from, the post hinge axis. A compression spring 34 is connected between plate 44 and the upper section 30 of the second latch member 26. The spring urges the second latch member 26 about the second hinge axis in a direction to engage the first latch member 20 when the post 8 is rotated into the obstructing position.
The urging force of the spring 34 upon the second latch member 32 causes the opposing convex camming surfaces of both latch members 20 and 26 to come into contact with each other when the post is rotated toward its upright position. When the camming surfaces engage each other latch member 26 rotates clockwise about the axis of hinge 28. Ultimately, when the post is vertical, latch members 20 and 26 snap into engagement with each other under the action of spring 34. Thus, the latch members 20 and 26 automatically reengage when the post 8 is rotated into the obstructing position.
An actuator 36, mounted on post 8, provides for manual disengagement of the first latch member 20 from the second latch member 26. The actuator, as shown in FIG. 3 comprises an actuating element 38, located in a recess found in a wall of the post, and accessible from the exterior of the post 8. The actuator element 38, is preferably in the form of a triangle having rounded corners, so that it can be actuated by a fire plug wrench. The actuator element 38 is fixed to a shaft 40, which is mounted in the post for rotation about a horizontal axis substantially parallel to the axis of hinge 10. A tongue 42 is rigidly attached to shaft 40 and extends downwardly past the upper end of latch member 26.
When actuating element 38 is rotated, tongue 42 comes into contact with the upper section 30 of the second latch member 26. When the opposing force of spring 34 is overcome, the camming element 42 will rotate the second latch member 26 counterclockwise about the second hinge axis. This rotation disengages the lower section 32 of the second latch member 26 from the upper section 24 of the first latch member 20. The post 8 is then free to rotate about the post hinge 10 into the collapsed position.
The collapsible barrier 1 in accordance with the invention provides a flexible system for controlling vehicular access. It may function as a barrier to vehicles, or be folded into the collapsed position to allow them to pass. The use of a hinged latching element and a separate actuator allows the barrier to be folded to its collapsed condition swiftly and easily. The use of a second latch member hinged on an axis parallel to the post hinge, and a separate actuator provides for ease of operation and long-term reliability. The fact that the second latch member is connected to the post by a single articulating connection, provided by hinge 28, rather than through multiple articulating connections, enhances the strength of the barrier. The fact that the axis of hinge 28 is parallel to the axis of hinge 10 also contributes to the strength of the barrier. The barrier 1 is not only strong, reliable and durable, but also inexpensive to manufacture and to install.
Various changes may be made to the described embodiments. While a triangular device actuable by a fire plug wrench is preferred as the actuating element, any suitable device accessible from the exterior of the post 8 may be used to push the upper section 30 of the second latch element 26.
The base 2 does not need to be inserted into a below grade level foundation. Any method of affixing the base to the floor of the installation site may be utilized. For example the base 2 can take the form of a plate anchored to a floor by bolts.
The post 8 may be fashioned into any of various sizes and shapes. Large posts may be used to block trucks, while smaller ones may provide a sufficient barrier to motorcycles and automobiles.
Still other modifications, which will occur to persons skilled in the art, may be made without departing from the scope of the invention as defined in the following claims. | A collapsible barrier for controlling vehicular access to parking areas and transitways, comprises a base and an elongated post hinged to the base. A first latch member fixed to the base engages a second latch member to secure the post in an upright obstructing position. The second latch member is located within the post and hinged to rotate about an axis parallel to the post hinge axis. An actuator, accessible from the exterior of the post, swings the second latch member in a direction to disengage it from the first latch member. A spring, operating in conjunction with camming surfaces on the latch members, provides for automatic reengagement when the post is rotated into the obstructing position. | 4 |
FIELD OF INVENTION
The invention relates generally to methods and circuits for identifying a defective memory cell in an array of memory cells.
BACKGROUND
Conventionally, non-volatile semiconductor memory structures with high levels of integration (e.g., EPROM, EEPROM, flash EPROM, and the like) suffer from high defect rates. A significant percentage of defects common to non-volatile memory produce so-called “leaky” memory cells, which lead to memory misreads, greatly depressing memory yield.
FIG. 1 ( a ) (prior art) depicts a configurable memory cell 100 , including a storage transistor T 1 . Storage transistor T 1 includes a floating gate 115 , a control gate 117 connected to a wordline 120 , a drain terminal 125 connected to a bitline 130 , and a source terminal 135 connected to a ground terminal. During a programming operation, different voltages are applied to wordline 120 and bitline 130 causing electron tunneling from floating gate 115 to drain 125 . This transfer of negative charge from floating gate 115 decreases the threshold voltage of storage transistor T 1 (to a programmed threshold voltage V THP ). During an erase operation, different voltages are applied to wordline 120 and bitline 130 causing electron tunneling from drain 125 to floating gate 115 , the reverse of the programming process. This transfer of negative charge to floating gate 115 increases the threshold voltage of storage transistor T 1 (to an erased threshold voltage V THE ).
To read memory cell 100 , a read voltage V R is applied to wordline 120 . The threshold voltage V THP of a programmed cell is less than the read voltage V R , SO transistor T 1 conducts with read voltage V R applied to control gate 117 if memory cell 100 is programmed; in contrast, the threshold voltage V THE of an erased cell is above the read voltage V R , so transistor T 1 does not conduct with read voltage V R applied to wordline 120 if memory cell 100 is erased. Whether a given cell conducts with the read voltage applied to the control gate is therefore indicative of the program state of the cell. In the following examples, the programmed state corresponds to a logic-zero state (a “logic zero”) and the erased state corresponds to a logic-one state (a “logic one”).
FIG. 1 ( b ) (prior art) depicts a memory array 150 including N rows and M columns of memory cells 100 . Each row of memory array 150 includes M storage transistors T 1 with their respective control gates connected to one wordline. For example, all M control gates of storage transistors T 1 in a first row are connected to a first wordline WL<1>. Each column of memory array 150 includes N storage transistors T 1 with their respective drain terminals connected to one bitline. For example, all N drain terminals of storage transistors T 1 in a first column are connected to a first bitline BL<1>.
As discussed above in connection with FIG. 1 ( a ), programming and erasing memory cells 100 of memory array 150 includes applying appropriate voltages on the M wordlines and N bitlines. Program and erase voltages are chosen so that all memory cells 100 in memory array 150 exhibit a nominal programmed threshold voltage V THP and a nominal erased threshold voltage V THE . The nominal values of programmed and erased threshold voltages V THP and V THE determine the appropriate read voltage V R value used during a read operation.
During a read operation, all bitlines are pre-charged to a relatively high voltage representative of a logic one. Then read voltage V R is applied to a selected wordline WL<K> while a read-inhibit voltage V RI less than the programmed threshold voltage V THP is applied to all unselected wordlines (i.e., the control gates of the cells-within memory array 150 not being read). Thus biased, only programmed memory cells on the selected wordline WL<K> will conduct, pulling respective bitlines to a low voltage level representative of a logic zero; and neither programmed nor erased cells on all unselected wordlines conduct.
Memory array 150 can have one or more defective memory cells. A memory cell is “defective” if its electrical characteristics are outside of an acceptable range. For example, a leaky memory cell exhibits a programmed threshold voltage V THP that is substantially less than required. If the programmed threshold voltage V THP of a given memory cell is below the read-inhibit voltage V RI , that memory cell will “leak” when not selected, causing the associated column to read a logic zero regardless of whether a programmed or erased cell is selected.
Modern memory circuits include spare rows or columns of memory cells that can be substituted for respective rows or columns that include defective cells. It can be difficult, however, to precisely locate some types of defects. For example, a leaky memory cell affects an entire column, making it difficult to single out the defective cell. Replacing the defective column solves the problem in many instances; however, redundant rows are preferred for some memory architectures, so it may be important to identify the defective row. Moreover, even in the absence of redundant rows or columns, identifying defective memory cells aids in troubleshooting manufacturing processes. There is therefore a need for circuits and methods for identifying individual defective memory cells.
SUMMARY
The present invention is directed to circuits and methods for identifying defective memory cells in memory arrays. In one embodiment, all the memory cells in an array are programmed to conduct with a conventional read voltage applied and not to conduct with a conventional read-inhibit voltage applied. Any rows that conduct with the read-inhibit voltage applied are termed “leaky,” and are defective. Another read-inhibit voltage lower than the conventional level is selected to cause even leaky cells not to conduct. This test read-inhibit voltage is consecutively applied to each row under test. If one of the rows includes a leaky bit, that bit will conduct with the conventional read-inhibit voltage applied but will not conduct with the test read-inhibit voltage applied. The test flow therefore identifies a row as including a leaky bit when a leak is suppressed by application of the test read-inhibit voltage. A redundant row can be provided to replace a row having a leaky bit.
In one embodiment, a memory array includes a test row and some wordline select logic. During a test operation, the wordline select logic simultaneously applies three wordline voltages, a pair of read-inhibit voltages V RI1 and V RI2 and a read voltage V R , to wordlines in the memory-cell array. The first wordline voltage V RI1 is an unusually low read-inhibit voltage of a level selected to insure that even leaky cells will not conduct. The second and third wordline voltages V RI2 and VR are conventional read-inhibit and read voltages, respectively.
In a test method in accordance with one embodiment, each memory cell is erased (i.e., is configured to exhibit a relatively high erased threshold voltage V THE ). Each row other than the test row is then programmed (i.e., is configured to exhibit a relatively low programmed threshold voltage V THP ). The wordline select logic then applies the conventional read voltage V R to the wordline of the test row. Being erased, the memory cells in the test row do not conduct. At the same time, the wordline select logic applies the low read-inhibit voltage VRI 1 to the wordline associated with one of the rows under test and applies the conventional read-inhibit voltage V RI2 to the remaining wordlines.
The read voltage on the test-row wordline is less than the erased threshold voltage, so the memory cells in the test row are biased off and will not conduct. The first read-inhibit voltage is less than the programmed threshold voltage, so low in fact that even leaky cells will not conduct. Thus, the memory cells within the associated row will not conduct even if leaky. Finally, the second read-inhibit voltage will prevent properly working programmed memory cells from conducting, but is insufficient to render leaky memory cells nonconductive. Thus biased, any conduction in the memory array indicates that one of the memory cells with the second read-inhibit voltage applied is leaking.
The first read-inhibit voltage is consecutively applied to each row under test. If one of the rows includes a leaky bit, that bit will conduct in every case except when the first read-inhibit voltage is applied to the leaky cell. The test flow therefore identifies a row as including a leaky bit when a leak is suppressed by application of a relatively strong read-inhibit voltage. Once a defective bit is identified, the row address of the leaky cell is stored for later consideration. Some embodiments include redundant rows, which can be substituted for row containing defective bits.
The allowed claims, and not this summary, define the scope of the invention.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 ( a ) (prior art) is a diagram of a memory cell.
FIG. 1 ( b ) (prior art) is a diagram of an N-by-M memory array.
FIG. 2 is a block diagram of a memory circuit.
FIG. 3 is a flow chart of a test method identifying a defective memory cell.
FIG. 4 a block diagram of an ISC memory assembly with redundancy row capability.
FIG. 5 is a detailed block diagram of a wordline select circuit.
FIG. 6 ( a ) is a detailed block diagram of a top decoder.
FIG. 6 ( b ) is a detailed circuit diagram of a two-stage voltage level shifter circuit.
FIG. 7 ( a ) is a detailed block diagram of row decoder.
FIG. 7 ( b ) is a detailed block diagram of a row driver.
FIG. 7 ( c ) is a detailed circuit diagram of a wordline driver.
FIG. 7 ( d ) is a detailed circuit diagram of a wordline multiplexer.
DETAILED DESCRIPTION
FIG. 2 depicts a memory circuit 200 in accordance with one embodiment of the invention. Memory circuit 200 includes a memory block 220 that conventionally includes an array of memory cells 270 arranged in a plurality of rows 260 and columns 265 . Each memory cell 270 is the same or similar to memory cell 100 of FIG. 1 ( a ). Memory circuit 200 additionally includes a test row 280 and a wordline select circuit 250 connected to rows 260 and 280 via a plurality of respective wordlines WL<1:N> and WLT. Wordline select circuit 250 is adapted to simultaneously apply three wordline voltages V RI1 , V RI2 , and VR to memory block 220 to support test methods that identify individual defective memory cells. The following example assumes a leaky memory cell 270 A for illustrative purposes.
FIG. 3 depicts a flow chart 300 illustrating a method of testing memory circuit 200 of FIG. 2 to identify defective memory cells (e.g., leaky memory cell 270 A in the example). The following discussion employs memory circuit 200 in conjunction with flow chart 300 .
Beginning with step 305 , each memory cell 270 within memory block 220 is erased (i.e., is configured to exhibit an erased threshold voltage V THE ). Next, in step 310 , each row except test row 280 is programmed (i.e., is configured to exhibit a programmed threshold voltage V THP ) In the following sequence of steps, the contents of test row 280 are read with each of the remaining rows 260 inhibited.
As with a normal read operation, bitlines BL<1:M> are pre-charged to a level representative of a logic one (step 315 ). In step 325 , wordline select circuit 250 simultaneously applies:
1. a read voltage V R to test row 280 via test wordline WLT;
2. a first read-inhibit voltage V RI1 to one of rows 260 to be tested for leaky bits (e.g., wordline WL<K−1>); and
3. a second read-inhibit voltage V RI2 to the remaining wordlines (e.g., wordlines WL<1> through WL<K−2> and WL<K> through WL<N>).
Read voltage V R is greater than programmed threshold voltage V THP but less than erased threshold voltage V THE . Thus, memory cells in test row 280 are off and do not affect the logic state of the pre-charged bitlines. First read-inhibit voltage V RI1 is less than programmed threshold voltage V THP , and is selected to be sufficiently low that even leaky cells will not conduct with read-inhibit voltage V RI1 applied on the respective wordline; thus, memory cells in the row 260 to which first read-inhibit voltage V RI1 is applied do not conduct even if leaky. Second read-inhibit voltage V R12 is a conventional read-inhibit voltage; thus, memory cells in the rows 260 to which read-inhibit-voltage V RI2 is applied conduct if leaky but do not otherwise conduct. In one embodiment, read voltage V R is three volts, programmed threshold voltage V THP is about zero to 1.5 volts, erased threshold voltage is about 4 to 6 volts, second read-inhibit voltage V RI2 is negative two volts, and first read-inhibit voltage V RI1 is negative four volts.
Next, in step 330 , the logic states of bitlines BL<1:M> are examined with the three wordline voltages applied. Any logic zeroes indicate the presence of a leaky memory cell among the cells to which read-inhibit voltage V RI2 is applied. In the illustration of FIG. 2, defective memory cell 270 A is provided with a read-inhibit voltage V RI2 insufficient to turn off leaky memory cell 270 A, so bitline BL<M−1> is pulled down to a low logic level, indicating an error. Due to the resulting mismatch between the level provided on bitline BL<M−1> and the expected correct level, wordline select circuit 250 selects the next wordline WL<K> for application of read-inhibit voltage V RI (step 340 ) and the process returns to step 315 .
Steps 315 through 330 are repeated, this time with first read-inhibit voltage V RI1 applied to wordline WL<K>, the wordline associated with leaky memory cell 270 A. Because read-inhibit voltage V RI1 is low enough to render a leaky cell non-conductive, bitline BL<M−1> will no longer produce an error. The test flow therefore indicates that the relatively low read-inhibit voltage V RI1 is currently suppressing the leaky bit, identifying the row associated with the selected wordline WL<K> as including the leaky memory cell. The row address of the leaky cell is then stored (step 345 ) for later consideration. Where redundant rows are included, the row address of leaky cell 270 A can be used to substitute the associated defective row with a redundant row (step 350 ).
FIG. 4 depicts a memory assembly 400 with row substitution capability in accordance with one embodiment of the invention. Memory assembly 400 includes memory circuit 200 of FIG. 2 in communication with an in-system configuration (ISC) memory access circuit 410 and a row substitution circuit 450 . Memory circuit 200 receives read voltage V R , first read-inhibit voltage V RI1 , second read-inhibit voltage V RI2 , and control signals via a control bus CTL 0 . Control bus CTL 0 conveys all signals required by wordline select circuit 250 for proper operation. ISC memory access circuit 410 supports a conventional JTAG protocol that allows configuration of devices mounted on a printed-circuit board. ISC memory access circuit 410 includes an address register 415 connected to a data shift register 420 . Address register 415 receives-serial data on a serial input terminal T DI and serially transmits the data to data shift register 420 . Also, address register 415 can transmit parallel address data to row substitution circuit 440 . Data shift register 420 includes the same number of bits as the columns of memory block 220 . Each bit of data-shift register 420 connects to a corresponding one of the plurality of bitlines. Thus, data shift register 420 either receives serial data from address register 415 or parallel data from bitlines BL<1:M>, and either transmits serial data on output serial terminal TDO or parallel data to bitlines BL<1:M>.
Row substitution circuit 450 includes a redundant row 430 , similar to rows 260 of FIG. 2, and a row substitution control circuit 440 . Redundant row 430 includes M memory cells, each connected to a swap wordline SWL and a corresponding one of bitlines BL<1:M>. Row substitution control circuit 440 receives and stores the address of a defective row, as discussed with respect to flowchart 300 of FIG. 3, and controls access to redundant row 430 through swap wordline SWL. For each memory access (read or write), row substitution circuit 440 ,compares the stored address to the contents of address register 415 . If a match is found, indicating address register 415 contains an address for a row identified as defective, row substitution circuit 440 directs the memory access to redundant row 430 and generates a disable signal in response to this address, which disables access to all rows but the redundant-row. Memory assembly 400 thus facilitates row substitution to correct for defective memory cells.
FIG. 5 is a block diagram 500 of wordline select circuit 250 (FIGS. 2 and 4) in accordance with one embodiment. Wordline select circuit 250 includes a top decoder 520 receiving and transmitting signals to a row decoder 540 . Wordline voltages V R , V RI1 , and V RI2 are provided to wordline select circuit 250 on like-named terminals. The remaining terminals are part of control bus CTL 0 of FIG. 4 . Top decoder 520 receives control signals A 1 , A 2 , and enable-select signal ENS and transmits input voltage VPNF to row decoder 540 via a selected one of wordline-select lines SELW<1:4>, and input voltage VNNCG via the unselected ones of wordline-select lines SELW<1:4>. Table 1 describes the logical functionality of top decoder 520 .
TABLE 1
ENS
A1
A2
SELW<1>
SELW<2>
SELW<3>
SELW<4>
0
0
0
VPNF
VNNCG
VNNCG
VNNCG
0
0
1
VNNCG
VPNF
VNNCG
VNNCG
0
1
0
VNNCG
VNNCG
VPNF
VNNCG
0
1
1
VNNCG
VNNCG
VNNCG
VPNF
1
X
X
VPNF
VPNF
VPNF
VPNF
In a normal read operation, row decoder 540 applies a read voltage VR to a selected wordline and a conventional read-inhibit voltage to the unselected wordlines. In a test-row read operation, row decoder 540 applies read voltage VR to test wordline TWLT, read-inhibit voltage VRI 1 to one of wordlines WL<1:N>, and read-inhibit voltage VRI 2 to the remaining wordlines. Select signals on lines SELB<1:M> and ELW<1:4> determine which wordlines receive which read-inhibit voltage. Decoders 520 and 540 are detailed below.
FIG. 6 ( a ) is a block diagram 600 of an embodiment of top decoder 520 of FIG. 5 . Top decoder 520 includes wordline-select circuit 610 receiving control signals A 1 , A 2 , and enable-select ENS and transmitting enable-select-wordline signals ENSW<1:4> to respective select-wordline drivers 620 . Enable-select-wordline signals ENSW<1:4> control whether select-wordline driver 620 transmits input voltage VPNF or input voltage VNNCG to a wordline-select terminal. Thus during operation, wordline-select circuit 610 enables only one of select-wordline drivers 620 to transmit input voltage VPNF on respective wordline-select terminal SELW<1:4> as shown above in Table 1.
FIG. 6 ( b ) details an embodiment of select-wordline driver 620 of FIG. 6 ( a ). Select-wordline driver 620 includes a voltage-level shifter 660 that shifts enable-select-wordline signal ENSW from switching between a voltage range of zero-to-VDD to a voltage range of zero-to-VPNF. Voltage-level shifter 660 then applies the level-shifted signal to a second voltage-level shifter 670 .
Voltage-level shifter 670 shifts the level shifted signal from a voltage range of zero-to-VPNF to a voltage range of VNNCG-to-VPNF. Voltage-level shifter 670 transmits the resulting voltage-level shifted signal to an output circuit 680 . Output circuit 680 then generates a select-wordline signal SELW, a version of enable-select wordline signal ENSW, exhibiting a broader voltage range. In one embodiment, input voltages VPNF and VNNCG are three and negative four volts, respectively. Select-wordline circuit 620 thus level-shifts enable-select wordline signals ENSW, switching between supply voltage and ground, to output signal (enable-select wordline ENWL), switching between three and negative four volts.
FIG. 7 ( a ) details row decoder 540 of FIG. 5 in accordance with one embodiment of the invention. As noted above, row decoder 540 applies read-inhibit voltage V RI1 to one of wordlines WL<1:N> and applies read-inhibit voltage V RI2 to the remaining wordlines.
Row decoder 540 includes a plurality of row driver blocks 710 and a test row driver block 720 . Each row driver block 710 connects to select-wordline signals SELW<1:4> and one of M select-block signals SELB<1:M>. The appropriate select-block signals SELB<i> (a block index).and select-wordline signals SELW<1:4> are asserted to apply the first read-inhibit voltage V RI1 to a selected wordline; the remaining wordlines receive the second read-inhibit voltage V RI2 . To apply the first read-inhibit voltage on wordline WL<3>, for example, select-block signal SELB<1> and select-wordline signal SELW<3> are asserted.
Test row driver block 720 is similar to row driver blocks 710 , but is modified such that it is active only during test-row read operations. During a test-row read operation, test-select-wordline signal SELt is asserted and read voltage V R applied to terminal V RI1 . In response, test row driver block 720 transmits read voltage V R to test wordline WLT.
FIG. 7 ( b ) details an embodiment of row driver 710 of FIG. 7 ( a ). Row driver 710 includes an enable-wordline driver circuit 765 similar to select-wordline driver 620 of FIG. 6 ( a ) receiving input voltages,. VPNF and VNNCG, and a select-block signal SELB; and transmitting an enable-wordline driver signal ENWLD to wordline drivers 770 . Similar to select-wordline driver 620 , enable-wordline driver 765 shifts seiect-block signal SELB<i> from switching between a voltage range of zero-to-VDD to an enable-wordline driver signal ENWLD switching between a voltage range of VNNCG-to-VPNF. Enable-wordline driver 765 then transmits enable-wordline driver signal ENWLD to wordline drivers 770 . Table 2 summarizes logic functionality of enable-wordline circuit 765 .
TABLE 2
SELB<i>
ENWLD
0
VNNCG
1
VPNF
Wordline drivers 770 receive an enable-wordline driver signal ENWLD and a respective one of select-wordline signals SELW<1:4>, and either transmits a first read-inhibit voltage VRI 1 or a second read-inhibit voltage VRI 2 on wordline terminal WL. Table 3 summarizes the functionality of wordline drivers 7706 .
TABLE 3
ENWLD
SELW0
SELW1
SELW2
SELW3
WL<0>
WL<1>
WL<2>
WL<3>
VPNF
VPNF
VNNCG
VNNCG
VNNCG
VRI1
VRI2
VRI2
VRI2
VPNF
VNNCG
VPNF
VNNCG
VNNCG
VRI2
VRI1
VRI2
VRI2
VPNF
VNNCG
VNNCG
VPNF
VNNCG
VRI2
VRI2
VRI1
VRI2
VPNF
VNNCG
VNNCG
VNNCG
VPNF
VRI2
VRI2
VRI2
VRI1
VNNCG
X
X
X
X
VRI2
VRI2
VRI2
VRI2
From table 3 it can be seen that only the selected wordline transmits first read-inhibit voltage V RI1 while all unselected wordlines transmit second read-inhibit voltage V RI2 Thus during each test row read operation, only one wordline, the selected wordline, transmits head inhibit voltage V RI1 .
FIG. 7 ( c ) details an embodiment of row driver circuit diagram 770 of FIG. 7 ( b ). Wordline driver 770 includes conventional NAND and inverter gate configurations 780 and 785 , respectively, having VPNF and VNNCG as supply voltages. NAND configuration 780 applies output signal EN to inverter configuration 785 and to a first control terminal of multiplexer 790 . Inverter configuration 785 applies output signal ENb to a second control terminal of multiplexer 790 . Multiplexer 790 transmits either first read-inhibit voltage V RI1 or second read-inhibit voltage VRI 2 to wordline output terminal WL as directed by control signals EN and ENb.
FIG. 7 ( d ) details an embodiment of multiplexer 790 of FIG. 7 ( c ). Multiplexer 790 includes first and second CMOS full pass gates 796 and 798 that alternately pass first read-inhibit voltage V RI1 or second read-inhibit voltage V RI2 as directed by enable signals EN and ENb.
While the present invention has been described in connection with specific embodiments, variations of these embodiments will be obvious to those of ordinary skill in the art. For example, instead of applying the second read-inhibit voltage to selected wordline and the first read-inhibit voltage to unselected wordlines, the first read-inhibit voltage can be applied to selected wordline and the second read-inhibit voltage to unselected wordlines. Moreover, some components are shown directly connected to one another while others are shown connected via intermediate components. In each instance the method of interconnection establishes some desired electrical communication between two or more circuit nodes, or terminals. Such communication may often be accomplished using a number of circuit configurations, as will be understood by those of skill in the art. Therefore, the spirit and scope of the appended claims should not be limited to the foregoing description. | Disclosed are circuits and methods of identifying defective memory cells among rows and columns of memory cells. In one embodiment, all the memory cells in an array are programmed to conduct with a conventional read voltage applied and not to conduct with a conventional read-inhibit voltage applied. Any rows that conduct with the read-inhibit voltage applied are termed “leaky,” and are defective. Another read-inhibit voltage lower than the conventional level is selected to cause even leaky cells not to conduct. This test read-inhibit voltage is consecutively applied to each row under test. If one of the rows includes a leaky bit, that bit will conduct with the conventional read-inhibit voltage applied but will not conduct with the test read-inhibit voltage applied. The test flow therefore identifies a row as including a leaky bit when a leak is suppressed by application of the test read-inhibit voltage. A redundant row can be provided to replace a row having a leaky bit. | 6 |
BACKGROUND OF THE INVENTION
This invention relates to a holder for securely retaining in position an electronic or electrical part which is designed to be held in position at a distance from a circuit board or other object to which it is electrically connected.
Electronic and electric parts which are used in ordinary electric appliances are generally disposed on circuit boards so as to permit effective electric connection therebetween. Some of these parts, particularly lamps, transistor elements, photo-diodes, photo-transistors, etc., are often supported by the chassis or other kind of support plate etc. at a position spaced apart from the circuit board. In the case of transistors, for example, it has heretofore been customary for the transistor to be supported on the circuit board by its lead wires without additional support. Light-emitting elements and other parts designed for attachment to separate supporting plates have, on the other hand, been electrically connected with the circuit board with their lead wires loosely extended.
In the conventional method of supporting a transistor on the circuit board by its lead wires, there are numerous disadvantages in addition to the obvious disadvantage of the unstability of the lead wire disposition: the lead wires may short-circuit, interfere with other neighboring parts or sustain breakage and unexpected troubles may result from the exposure of the circuit board to external shocks. And in the case of the conventional method fastening a light-emitting element onto a separate supporting plate with its lead wire electrically connected with the circuit board, there are entailed disadvantages that the lead wire from the part must be given ample length to allow for freedom of motion during possible disassemblage of the electric appliance, that, in the worst case, the lead wire may fail to find a space between the base panel and the supporting plate, that the lead wire may possibly interfere with other adjacently located parts and that the expense of the part itself may be consequently increased to a considerably higher level. There is also the great disadvantage that the work involved in fastening the part to the supporting plate is quite complicated.
An object of the present invention is to provide a holder formed integrally of a plastic material in a construction such that it permits an electronic or electrical part to be securely held in position at a prescribed distance from the surface of the distributing base panel, gives it necessary protection, prevents it from interfering with other parts and enjoys advantageous workability.
SUMMARY OF THE INVENTION
To accomplish the object described above according to the present invention, there is provided a plastic holder for the secure retention of electronic and electrical parts possessing a flange, which holder comprises a leading portion possessing means for engagement with the flange of the part subjected to retention, a base portion possessing fastener means adapted for fast engagement with a base panel, a shank portion integrally connected at one end with the leading portion and at the other end with the base portion, and a hole pierced longitudinally through the shank portion from the leading portion side through the base portion side.
The holder of the present invention enables an electronic or electrical part to be retained securely in position at a prescribed distance from the surface of a circuit board by preparatorily perforating the circuit board to form therein an opening for engagement with the fastener means of the base portion of the holder, causing the electronic or electrical part to be fastened in position on the leading portion of the holder with the aid of the engaging means, allowing the lead wire from the part to pass through the hole pierced through the shank portion of the holder and finally fastening the holder to the base panel through fast engagement of the opening in the base panel with the fastener means.
The part can be securely retained in position at a prescribed distance from the circuit board by having the electronic or electrical part fastened in position on the leading portion of the holder and then bringing the holder into fast engagement with the circuit board. The desired secure retention of the part can be conveniently obtained by calculating the distance from the circuit board to the position prescribed for the retention of the part at the stage of design of the electric appliance for which the holder is intended and then selecting from among holders of this invention having varying lengths, the particular holder of the length that exactly conforms with the distance calculated in advance. Since the electronic or electrical part is supported in position by its flange and the joint between the part and its lead wire is consequently protected against impacts, otherwise possible troubles of lead wire breakage and part fracture can be prevented and the unwanted contact between bare wires can be precluded. Lamps and photo-diodes which by nature are designed for direct attachment to a separate chassis can be securely retained on one and the same circuit board by means of holders of the present invention. Thus, the present invention brings about simplification of circuitry and contributes to facilitation of the work involved in the assemblage and disassemblage of the electric appliance using the holders of the invention.
The other objects and characteristics of this invention will become apparent from the description to be given in detail hereinafter with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially cutaway perspective view illustrating the state of the wiring and electronic or electrical parts generally found in electric appliances.
FIG. 2 is a perspective view of one preferred embodiment of the holder of this invention for use with an electronic or electrical part.
FIG. 3 is a plan view of the holder of FIG. 2.
FIG. 4 is a sectioned view taken along the line IV--IV of FIG. 3.
FIG. 5 is a sectioned view of the holder of FIG. 2 illustrating the condition in which the holder is used for holding a part in position thereon.
FIG. 6 is an explanatory diagram illustrating electronic and electric parts for which the holder of the present invention can be used.
FIG. 7 is a partially cutaway perspective view illustrating another preferred embodiment of the holder of this invention.
FIG. 8 is a perspective view illustrating still another preferred embodiment of the holder of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Most electronic and electrical parts in ordinary electric appliances in general use are directly connected to and fastened in position on circuit boards. For the convenience of wiring, the practice of planting necessary parts on one (obverse) side of a printed-circuit base panel as illustrated in FIG. 1 has found widespread acceptance in the electronic/electric industry. Most electronic and electrical parts have their lead wires passed through fine holes perforated in a printed circuit board, and led to and soldered at their respective points of connection on conductors which are printed on the reverse side of the board. For a resistor, a condenser, etc., the length of the lead wires may be decreased as much as possible. In the case of a semiconductive part 1, however, it is desirable to make the lead wires as long as possible so that the part can be kept unaffected by the heat of soldering. If this semiconductive part happens to be a photo-diode or the like, there is a necessity of having the part disposed at an unusually large distance from the surface of the distributing base panel. The frequency with which such undesirable phenomena as short-circuiting, wire breakage and interference with other neighboring parts are induced by such extended lead wires increases with the increasing length given to the lead wires. A photo-diode or photo-transistor 2 is sometimes fastened in position on a supporting plate such as a chassis C which is spaced some distance from the circuit board, with a lead wire 3 serving to establish the necessary electric connection. In most cases, the lead wire of this nature is given ample extra length as illustrated so as to facilitate the assemblage and disassemblage of the electric appliance.
Use of the holders of the present invention helps to overcome the aforementioned disadvantages, eliminate wasted time and labor, facilitate the work of wiring and realize secure retention of parts in position.
As illustrated in FIGS. 2-4, the holder of the present invention is integrally formed of a plastic material in a construction comprising a leading portion 5, a shank portion 6, and a base portion 7.
The leading portion 5 is incised with a retaining hole 8 for accommodating a flange 16 of an electronic or electrical part such as a photo-diode 15 designed to be disposed in position at a distance from the circuit board. This retaining hole 8 is provided on the inner circular wall thereof with spaced projecting catches 9 serving to catch hold of the flange 16 of the part. These projecting catches have a triangular cross section and they protrude inwardly from the inner circular wall of the retaining hole 8 of a size capable of receiving into tight engagement the flange 16 of the part. At the time that the flange 16 of the part is being received into the retaining hole 8, therefore, the advance of the flange 16 into the depth of the hole is obstructed by the catches 9. Since the projecting catches are a part of the holder integrally formed of a plastic material and, therefore, possess the flexibility of the plastic material, the flange 16 of the part can easily be pushed past the catches into the depth of the retaining hole. The base portion 7 has a flat bottom surface to ensure stable retention of the entire holder and also possesses fastener means 11 adapted for fast engagement of the holder with the circuit board. These fastener means 11 are each in the shape of a hook containing a shoulder part 12. They are brought into hooked engagement with the edge of an opening 18 perforated in advance in the circuit board P by causing the shoulder parts to be advanced forcibly past the opening 18 (FIG. 5).
The shank part 6 serves to interconnect integrally the leading portion 5 and the base portion 7 and contains internal through-holes 10 extending from the leading portion to the base portion. These through-holes 10 serve the dual purpose of separating the two component lines of the lead wire 17 and guiding them to their respective points of connection 19 on the distributing base panel P. The number of these through holes has only to be identical with that of the component lines of the lead wire of the relevant part. The shape in which the shank part 6 is formed is not critical insofar as the shank part fulfils its purpose of interconnecting the leading portion and the base portion and providing necessary through holes for the guidance of the lead wire. Holders of various heights can be obtained by giving this shank part various lengths conforming with the various prescribed distances between the circuit board P and the chassis C. In the case of holders which are used for the only purpose of retaining ordinary semiconductors, only a moderate height is satisfactory.
Now, a typical manner of fastening an electronic or electrical part with a holder of the foregoing construction will be described. First, the individual lead wires 17 from the part are inserted into the through-holes which open into the leading portion 5 of the holder and the flange 16 of the part is pushed into the retaining hole 8 (FIG. 2). The holder which has the part fastened in position on the leading portion as described above is attached fast to the circuit board by having the fastener means 11 of the base portion inserted past and brought into hooked engagement with the opening 18 perforated in advance in the circuit board P. Thereafter, the secure attachment of the part to the circuit board is completed by causing the leading ends of the lead wire extending from the through holes of the base portion to be soldered at their respective points of connection to the base panel.
Use of the holder of the present invention proves particularly advantageous where a light-emitting element 15 is desired to be visible from the outside of a chassis C which is located at a distance from the circuit board P as illustrated in FIG. 5. The secure attachment of the light-emitting element in this case is accomplished by a simple procedure of first fastening the light-emitting element 15 through the medium of the holder having a suitable length to the base panel P, then allowing the light-emitting element to protrude from the hole perforated in advance in the chassis C and finally disposing fast the base panel in position.
The parts for which the holders of the present invention are usable are not limited to photo-diodes. They can be used with parts such as, for example, condensers 20 possessing a groove 21, transistors 22 possessing a flange 23 and lamps 24 possessing a bulged portion 25 which incorporate portions capable of being caught hold of by the engaging means of the leading portion of the holder (FIG. 6).
FIGS. 7-8 illustrate other preferred embodiments of the engaging means at the leading portion 5 for catching hold of the flange of the electronic or electrical part. The leading portion 5 of the holder illustrated in FIG. 7 has a groove 13 formed in the entire inner side wall of the retaining hole 8 adapted to accommodate the flange of the part, so that the part can be brought into very powerful retention by causing the flange thereof to be forcibly pushed into the groove. The means which the holder illustrated in FIG. 8 possesses for the engagement with the flange of the part consists of hook-shaped engaging catches 14 protruding from the upper surface of the leading portion 5. They are adapted for the flange of the part to be brought into hooked engagement therewith. Since these engaging means are formed of the same plastic material as the rest of the integrally formed holder and, therefore, possess the flexibility proper to the material, they permit the parts to be readily brought into engagement and consequent secure retention.
When the holder of the present invention is used for retaining a semiconductor possessing a high heat-generating property, it enjoys an additional advantage of accelerating the dissipation of the heat being generated within the semiconductor during its service. If the holder is expected to provide positive effect of heat dissipation, then it may be provided on the shank portion thereof with a multiplicity of fins, not shown.
Thus, incorporation of holders of the present invention into the circuit boards helps to reduce the labor involved in wiring, simplify the mechanism of wire distribution, improve the reliability of circuit performance and protect the parts in use. | A holder comprises a leading portion adapted to retain in position thereon an electronic/electric part, a base portion adapted to be secured to a distributing base panel and a shank portion serving to interconnect the leading portion with the base portion and having a hole pierced therethrough for guiding the lead wire of the electronic/electric part to the lower side of the base portion. The holder permits a given electronic/electric part which is set in position on the leading portion to be securely retained at a distance from the distributing base panel, with the base portion fastened to the base panel and the lead wire of the part passed through the hole and connected to the prescribed point of connection on the base panel. | 7 |
BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to a device for inspecting plant parts that are submersed under water, in particular for ultrasonic inspection of screws in the core baffle of a nuclear reactor pressure vessel.
It is necessary in a range of applications to undertake inspection of safety-related plant parts located at points under water that are difficult to access. Such a safety-related plant part is, for example, the screws with which the core baffle is fastened on the core barrel in the reactor pressure vessel of a nuclear reactor. In order to permit ultrasonic inspection of these screws, it is necessary to position an ultrasonic inspection head on the head of the screw by remote control with the aid of a manipulator, arranged outside the refueling cavity, in a water depth of up to 10 m.
Instead of the use of a manipulator arranged outside the refueling cavity, for the purpose of inspecting a cladding of a fuel pit, Japanese patent application JP 042 40 597 A, for example, discloses using a remote-controlled underwater vehicle fitted with an ultrasonic inspection head. However, because of the drives, illuminating devices and cameras required for it to be freely maneuverable, such an underwater vehicle has a relatively high intrinsic weight and, not least, because of a relatively voluminous float required thereby also has correspondingly large dimensions. It is therefore not not readily possible to approach points in the region of interior edges, for example the screws in the corner regions of the core baffle of a nuclear reactor pressure vessel.
In order to be able to use such an underwater vehicle also to position the inspection head at points that are difficult of access, it has become known in principle from U.S. Pat. No. 5,193,405 and European patent EP 0 461 506 B1 to arrange the inspection head at the free end of a manipulator arm having six axes. However, controlling such a freely movable manipulator arm is complicated, and because of the torques exerted by the force of gravity on the freely floating underwater vehicle as a function of the position of the manipulator arm, it is difficult to keep the vehicle in a stationary floating state. For these reasons, the prior art underwater vehicle is provided with a plurality of suction cups with the aid of which it must be fixed on a smooth surface. The field of use is thus limited to plant parts with smooth walls.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide an inspection device for submersed plant parts which overcomes the above-mentioned disadvantages of the heretofore-known devices and methods of this general type and which provides for an underwater vehicle that is not technically complicated and can also be used in the corner regions of a core baffle.
With the foregoing and other objects in view there is provided, in accordance with the invention, a device for inspecting submersed plant parts, comprising:
a remote-controlled underwater vehicle having an end face and a longitudinal central axis perpendicular to the end face;
a carrier pivotally mounted at the end face exclusively about a pivot axis oriented parallel to the longitudinal central axis of the underwater vehicle; and
a holding device for an inspection head mounted to the carrier at a spacing distance from the pivot axis.
The device is, in particular, configured for ultrasonic inspection of plant parts such as screws in a core baffle of a nuclear reactor pressure vessel.
In other words, the device includes a remote-controlled underwater vehicle that is provided at an end face with a carrier that can be pivoted or rotated exclusively about a pivot axis that is oriented parallel to a longitudinal central axis, running perpendicular to the end face, of the underwater vehicle. There is also provided a holding device for an inspection head that is arranged on the carrier at a spacing from the pivot axis. It is possible by this measure to move the inspection head into different positions relative to the underwater vehicle with the underwater vehicle stationary, and so it is also possible to inspect plant parts that are located offset from the longitudinal central axis of the underwater vehicle.
In a particularly advantageous refinement of the invention, the carrier provided with the test head is balanced out in such a way that virtually no torque acting on the carrier about the pivot axis is exerted by the force of gravity irrespective of the pivoting position of the inspection head. Owing to this measure, different inspection positions can be approached with a freely floating underwater vehicle without the need of further complicated control measures for balancing and maintaining the floating state.
In accordance with an added feature of the invention, the pivot axis is disposed at a spacing from the longitudinal central axis. Preferably, the pivot axis is disposed at an edge of the underwater vehicle. It is advantageous when the location and orientation of the pivot axis on the underwater vehicle and a spacing of the holding device from the pivot axis are coordinated with one another such that the inspection head can be brought into mutually opposite positions that project over a lateral edge of the underwater vehicle, or extend at least into a vicinity of it.
In accordance with an additional feature of the invention, there are provided a multiplicity of support elements on the carrier. They are disposed in a circumferential direction about the pivot axis and spaced apart from one another in the circumferential direction.
In accordance with another feature of the invention, a universal joint is provided for mounting the inspection head in the holding device.
In accordance with a further feature of the invention, the carrier comprises a ring having a center on the pivot axis, the ring is fixed on a shaft of a first rotary drive with at least one radial spoke.
In a preferred embodiment, the carrier is an optically transparent disc.
In accordance with a concomitant feature of the invention, the inspection head is rotatably mounted in the holding device about a central axis extending parallel to the pivot axis.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a device for inspecting plant parts located under water, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic outline view of a device in accordance with the invention during use for ultrasonic inspection of screws in the core baffle of a nuclear reactor pressure vessel;
FIG. 2 is a perspective view of the device according to the invention;
FIG. 3 is an elevational view of the end face of the device; and
FIG. 4 is a side elevational view of the device according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, the device comprises a basic vehicle in the form of a remote-controlled underwater vehicle 2 . Such a vehicle is known, for example, under the trade name SUSI from Framatome ANP GmbH, of Germany. In accordance with the invention, the underwater vehicle 2 is provided at its end face 4 with a carrier 6 that is pivotally mounted on the underwater vehicle 2 about a pivot axis 10 oriented parallel to the longitudinal central axis 8 , running perpendicular to the end face 4 , of the underwater vehicle 2 . A holding device 12 is disposed on the carrier 6 at a spacing from the pivot axis 10 . The holding device 12 is fitted with an inspection head 14 , an ultrasonic inspection head in the exemplary embodiment, such as is known, for example, from European patent application EP 0 452 516 A1.
FIG. 1 illustrates a situation such as arises from an ultrasonic inspection of screws 16 in the core baffle 18 of a reactor pressure vessel. As illustrated in FIG. 1 , a multiplicity of these screws 16 are located in corner positions of the core baffle 18 that cannot be directly (centrally) approached because of the relatively large dimensions of the underwater vehicle 2 . It is now possible to use the rotary or pivotable carrier 6 to inspect screws 16 in corner positions even when the underwater vehicle 2 is located laterally offset from these corner positions.
In accordance with FIG. 2 , the underwater vehicle 2 (drawn only schematically) is provided on its end face 4 with a camera 20 with integrated illumination, which can be used for visual monitoring of the traveling motion of the underwater vehicle 2 . Arranged on the underside of the underwater vehicle 2 is a first rotary drive 22 with a shaft 24 on which the carrier 6 is fastened at the end face. The carrier 6 is constructed in the exemplary embodiment from a ring 62 that is fixed via spokes 64 at the end face on the shaft 24 and can be pivoted—in the exemplary embodiment it can be endlessly rotated—about the pivot axis 10 . The holding device 12 is disposed on the ring 62 . The inspection head 14 is mounted in the holding device by universal joint. A second rotary drive 26 permits the inspection head 14 to be rotated about its central axis 28 in order to enable correct placement on the screw head, for example an internal polygon. Electric sliprings (not illustrated in the figures) serve to supply power to the two rotary drives, and to supply the ultrasonic inspection head 14 . This renders endless rotation of the carrier 6 possible.
A plurality of support elements 66 , axially parallel pins in the example, are disposed on the end face of the ring 62 ; in the event of faulty positioning they prevent damage to the inspection head 14 and serve for aligning the underwater vehicle 2 (longitudinal axis perpendicular to the wall).
Moreover, a balancing weight 68 is located opposite the inspection head 14 for the purpose of balancing out a weight load. In other words: the carrier 6 provided with the inspection head 14 is balanced out in such a way that the force of gravity exerts virtually no torque acting on the carrier 6 about the pivot axis 10 irrespective of the rotational position of the inspection head 6 . This measure facilitates the maintenance of a stationary floating state even when there is a rotary movement of the carrier 6 , and thereby facilitates the approach to the inspection position.
It may be seen in the plan view of the end face in accordance with FIG. 3 that the inspection head 14 can be brought into lateral positions by rotating the carrier 6 about the pivot axis 10 . The latter is located at a spacing distance from the longitudinal central axis 8 at the edge, below the underwater vehicle in the example. These positions are approximately aligned with the lateral edge 30 , that is to say the lateral rim of the underwater vehicle 2 .
Instead of a ring 62 illustrated in the figures, it is also possible to provide a transparent disk made from plastic as carrier 12 for the inspection head 14 .
In accordance with FIG. 4 , the inspection head 14 is mounted in the holding device 12 in a resilient fashion in the direction of its transmitting or central axis 28 . This is illustrated by the double arrow. The support elements 66 compel an axially parallel position of the inspection head 14 relative to the screw to be inspected, and prevent the inspection head 14 from being overloaded or damaged by the underwater vehicle 2 drifting away to the side.
The inspection head 14 is now positioned over the screw head with the aid of the underwater vehicle 2 , and applied flush to the screw head by appropriately controlling the drive units of the underwater vehicle 2 . The correct positioning and coupling can be monitored with the aid of the echo signals picked up by the inspection head 14 . The drive units arranged in the underwater vehicle 2 hold the inspection head 14 , by exerting a slight contact pressure on the screw head, until the inspection is terminated. Further docking measures for holding the inspection position are not required because of the precision of the control of the underwater vehicle 2 .
This application claims the priority, under 35 U.S.C. § 119, of German patent application No. 103 17 191.6, filed Apr. 15, 2003; the disclosure of the prior application is herewith incorporated by reference in its entirety. | A device for inspecting submersed plant parts is particularly suited for ultrasonic inspection of screws in the core baffle of a nuclear reactor pressure vessel. The device includes a remote-controlled underwater vehicle that is provided at its end face with a carrier that can be pivoted about a pivot axis oriented parallel to the longitudinal central axis of the underwater vehicle, and is provided with a holding device for an inspection head that is arranged on the carrier spaced apart from the pivot axis. | 6 |
FIELD OF THE INVENTION
The present invention relates generally to a roller for fixing an ink image on a receiving medium and, more particularly, to a multi-layer pressure roller that creates a narrow, high pressure nip and includes an outer compliant elastomeric layer that provides improved ink image fixation on the receiving medium with reduced thermal requirements.
BACKGROUND OF THE INVENTION
Ink-jet printing systems commonly utilize either direct printing or offset printing architecture. In a typical direct printing system, ink is jetted from nozzles in the print head directly onto the final receiving medium. In an offset printing system, the print head nozzles jet the ink onto an intermediate transfer surface, such as a liquid layer on a drum. The final receiving medium is then brought into contact with the intermediate transfer surface and the ink image is transferred and fixed (transfixed) to the medium.
In direct and offset printing systems that utilize phase change ink, it is common to fix the ink image on the final receiving medium by passing the medium through a pressurized nip defined by a pair of rollers. The rollers are biased together to create the nip by spring loading the outer ends of at least one of the rollers in a direction normal to the longitudinal axis of the roller. To maximize the nip pressure, the outer layer of one or both of the rollers is typically made from a rigid material having a high durometer or hardness.
To produce a high quality image, it is necessary for the rollers to create a nip that applies substantially uniform pressure across the length of the nip. In some ink-jet printing applications, such as phase change color ink-jet systems using subtractive color mixing techniques, both single and multiple layers of ink pixels are applied to the final receiving medium. This results in surface areas of the medium having different thicknesses of ink, such as where a single ink pixel is adjacent to multiple layers of ink pixels. To achieve high image quality, the rollers must apply uniform pressure to the areas of the medium containing both single and multiple layers of ink pixels, notwithstanding their different thicknesses or heights. Accordingly, in addition to being sufficiently rigid to create the high pressure nip, it is also desirable for the roller to have a measure of compliance to conform to various ink thickness on the final receiving medium.
A roller with insufficient compliance produces a non-uniform nip pressure that promotes media wrinkling and incomplete image transfer and/or fixation on the media. To compensate for lower or insufficient roller compliance, many prior art phase change ink-jet printing systems utilize preheated media and/or elevated ink temperatures to facilitate image transfer and fixation. However, as the temperatures of the ink and the media increase, so do their coefficients of friction. This, in turn, promotes media wrinkling and reduced image quality. Additionally, the higher temperatures and coefficients of friction also make duplexing impractical, as the duplexed image is likely to smear. This occurs when the elevated preheat temperatures soften the ink in the first printed image and thereby make it more susceptible to smearing as the medium passes through the pressurized nip for the second time.
With specific regard to offset printing applications, non-uniform nip pressure results in diminished image transfer capability as well as media wrinkling. Image transfer relates to the percentage of ink droplets that are transferred from the intermediate transfer surface to the final receiving medium during the transfer printing process. For optimal image transfer, the outer layer of the transfer roller must be sufficiently compliant to conform to the different thicknesses of the single-and multiple-layers of ink pixels.
An exemplary patent directed to an offset ink-jet printer is U.S. Pat. No. 5,502,476, for METHOD AND APPARATUS FOR CONTROLLING PHASE-CHANGE INK TEMPERATURE DURING A TRANSFER PRINTING PROCESS, assigned to the assignee of the present application. This patent teaches the use of a pressure roller having a metallic core and a single elastomeric covering. The elastomeric covering engages the final receiving medium on the side opposite to the side that contacts the intermediate transfer surface to transfix the ink image to the final receiving medium. The nip in the '476 printer is created between the roller and a drum that supports the intermediate transfer surface, with the nip pressure being in the range between 500 and 600 pounds per square inch (psi)(between 3,447 and 4,137 kPa).
Prior to transfixing the ink image, the '476 printer preheats the final receiving medium and the ink on the intermediate transfer surface. To provide acceptable image transfer and final image quality, the '476 printer utilizes relatively high medium preheat temperatures in the range of about 85° C. to about 105° C. These media temperatures are in the region that softens the ink and preclude duplex printing.
With regard to direct printing applications, one prior art patent directed to improving nip pressure uniformity is U.S. Pat. No. 5,092,235 for a PRESSURE FIXING AND DEVELOPING APPARATUS, also assigned to the assignee of the present application. This patent discloses dual pressure rollers that each utilize a contoured core to control the pressure distribution across the nip. One of the rollers includes a rigid, non-compliant external shell that provides a hard surface against which the ink coated surface of the final receiving medium passes within the nip. The other roller includes a more compliant shell, such as nylon, covering an elastomeric material that is affixed to the core. The nylon shell allows the roller to more effectively treat paper containing different thicknesses of ink. The '235 roller, however, still lacks the necessary compliance for effective image transfer in an offset printing system.
While the prior art pressure rollers have proven generally adequate for their intended purposes, a need remains for an improved pressure roller that combines rigidity on a macro level for high nip pressure along the entire nip with compliance on a micro/pixel-to-pixel level for improved transfer and/or fixing of ink pixel layers having different heights. The roller should be capable of generating a high nip pressure without requiring excessive end loads. It is also desirable that the roller exhibit the above characteristics while operating with lower medium and ink preheat temperatures to reduce media wrinkling and allow duplexing capability.
SUMMARY OF THE INVENTION
It is an aspect of the present invention to provide a pressure roller for fixing an ink image on a receiving medium.
It is another aspect of the present invention to provide a pressure roller that creates a substantially uniform nip pressure across a final receiving medium having single and multiple layers of ink pixels.
It is a feature of the present invention that the pressure roller exhibits rigidity on a macro level to create high nip pressure along the entire nip.
It is another feature of the present invention that the pressure roller also exhibits compliance on a micro/pixel-to-pixel level for improved ink image transfer and/or fixation.
It is yet another feature of the present invention that the pressure roller creates a narrow and high pressure nip without requiring excessive end loads.
It is still another feature of the present invention that the pressure roller utilizes three layers of urethane for improved layer-to-layer bonding and greater fatigue resistance.
It is an advantage of the present invention that the pressure roller provides compliance across the exposed surface area of adjacent pixels for improved image transfer in an offset printing architecture.
It is an advantage of the present invention that the pressure roller allows for lower media and ink preheat temperatures to reduce media wrinkling and allow for duplex printing capability.
To achieve the foregoing and other aspects, features and advantages, and in accordance with the purposes of the present invention as described herein, an improved pressure roller for transferring and/or fixing an ink image on a receiving medium is provided. The pressure roller combines wide-scale rigidity for a high pressure nip with localized compliance for complete ink image transfer and/or fixation on the receiving medium. The high pressure nip and the improved compliance allow for lower media and ink preheat temperatures to reduce media wrinkling and to permit duplex printing. The roller also utilizes a multi-layered construction that creates the high nip pressure without requiring excessive end loads.
Still other aspects of the present invention will become apparent to those skilled in this art from the following description wherein there is shown and described a preferred embodiment of this invention, simply by way of illustration of one of the modes best suited to carry out the invention. As it will be realized, the invention is capable of other different embodiments and its several details are capable of modifications in various, obvious aspects all without departing from the invention. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive. And now for a brief description of the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic illustration of an offset ink-jet printing apparatus that utilizes the pressure roller of the present invention, the roller being biased toward a supporting surface to form a nip there between.
FIG. 2 is a side elevational view in cross section of the pressure roller of the present invention.
FIG. 3 is an enlarged partial side view in cross section showing the core of the roller and the multiple elastomeric layers surrounding the core.
FIG. 4 is a schematic pictorial diagram showing a single layer ink pixel positioned between two dual layer ink pixels, and showing the final receiving medium contacting the top surface of the dual layer pixels.
FIG. 5 is a schematic pictorial diagram showing an outer surface of the outer compliant elastomeric layer conforming to press the final receiving medium into contact with the single ink pixel, and showing an inner surface of the outer compliant elastomeric layer remaining substantially rigid to transmit maximum pressure to the medium.
Reference will now be made in detail to the present preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is an illustration of an offset ink-jet printing apparatus 10 that utilizes the pressure roller 20 of the present invention. An example of this type of printing apparatus is disclosed in U.S. Pat. No. 5,389,958 entitled IMAGING PROCESS and assigned to the assignee of the present application. The '958 patent is hereby specifically incorporated by reference in pertinent part. The following description of a preferred embodiment of the roller of the present invention refers to its use in this type of printing apparatus. It will be appreciated, however, that the roller of the present invention may be used with various other printing apparatus that utilize different imaging technologies and/or architectures, such as laser imaging in which multiple layers of toner must be fixed to a receiving medium. Accordingly, the following description will be regarded as merely illustrative of one embodiment of the present invention.
With continued reference to FIG. 1, a print head 11 is supported by an appropriate housing and support elements (not shown) for either stationary or moving utilization to place ink drops 28 in the liquid or molten state on an intermediate transfer surface 12. The intermediate transfer surface 12 is a liquid layer that is applied to a supporting surface 14, such as a belt, drum, web, platen, or other suitable design. The intermediate transfer surface 12 is applied by contacting the supporting surface 14 with an applicator, such as a metering blade, roller, web, or a wicking pad 15 contained within an applicator assembly 16.
Supporting surface 14 (hereafter "drum 14") may be formed from or surface coated with any appropriate material, such as metals including but not limited to aluminum, nickel, or iron phosphate, elastomers including but not limited to fluoroelastomers, perfluoroelastomers, silicone rubber, and polybutadiene, plastics including but not limited to polyphenylene sulfide loaded with polytetrafluorethylene, thermoplastics such as polyethylene, nylon, and FEP, thermosets such as acetals, and ceramics. The preferred material is anodized aluminum.
A media guide 18 passes a final receiving medium 22, such as paper or a transparency, from a positive feed device (not shown) past a media preheater 23 and into a nip 24. The nip 24 is formed by urging together the opposing arcuate surfaces of the pressure roller 20 of the present invention, described in more detail below, and the intermediate transfer surface 12 supported by drum 14. The drum 14 and pressure roller 20 are shown rotating in the direction of action arrows A and B, respectively, to pass the medium 22 through the nip 24. Typically, the drum 14 is positively driven while the pressure roller 20 is driven by being in surface contact with the drum. Of course, the drum 14 and pressure roller 20 may be geared or otherwise coupled together for driving purposes or separately driven if desired. After the medium 22 passes through the nip 24, stripper fingers 26 (only one of which is shown) may be pivotally mounted to the printing apparatus 10 to assist in removing medium 22 from the intermediate transfer surface 12.
The drum 14 and pressure roller 20 are urged together at their respective ends by a biaser 60. An example of a suitable biaser is the spring mechanism disclosed in U.S. Pat. No. 5,092,235, entitled PRESSURE FIXING AND DEVELOPING APPARATUS and assigned to the assignee of the present application. The '235 patent is hereby specifically incorporated by reference in pertinent part. It will be appreciated that other suitable biasers may be used including, but not limited to, solenoids, motors and pneumatic and hydraulic cylinders.
The ink utilized in the printing apparatus 10 is preferably initially in solid form and is then changed to a molten state by the application of heat energy to raise its temperature to within a range of between about 85° C. to about 150° C. The molten ink drops 28 are then ejected from ink jets (not shown) in print head 11 to the intermediate transfer surface 12, where they are cooled to an intermediate temperature and solidify to a malleable state. The intermediate temperature wherein the ink is maintained in the malleable state is between about 40° C. to about 60° C., and preferably about 50° C. To maintain the ink at the desired intermediate temperature, a drum heater 21 may be utilized. After they are deposited on the intermediate transfer surface 12, the ink drops 28 are then transfixed to the final receiving medium 22 by passing the medium through the pressurized nip 24 between the roller 20 and the intermediate transfer surface 12 on drum 14. Prior to entering the nip 24, the medium 22 is preheated by the preheater 23 to a temperature within a range of about 55° C. to about 75° C., and preferably to about 63° C.
Reference will now be made in detail to a preferred embodiment of the roller 20 of the present invention. As shown in FIGS. 2 and 3, the roller 20 rotates about two ball bearings 29, one at each end of the roller. The bearings 29 are seated in an elongated core 30. Preferably, the core 30 is made from a rigid, non-compliant material, such as cold drawn steel. The core 30 may be solid or hollow and may have various shapes and cross-sectional dimensions. In the preferred embodiment, the core 30 is a hollow cylinder with a generally increasing transverse cross-sectional dimension from the respective ends of the core to the center of the core. More specifically, the core 30 illustrated in FIG. 2 is contoured in longitudinal cross-section to have a crown, generally represented by the reference numeral 31, in the center and a decreasing diameter moving toward the ends.
Mathematically, the contour of the core 30 is approximated by a beam deflection curve for a simply supported, uniformly loaded, constant cross-section beam. The preferred contour for the illustrated core 30 is approximated by a curve defining the diameter D ofthe core as: D=1.721466+(-0.008524)X+(0.0065)X 2 +(-0.002276)X 3 +(0.000223)X 4 , where X is the absolute distance from the center of the core. Advantageously, this contour offsets the deflection of the roller 20 under load by creating a higher nip pressure at the center of the roller. Consequently, when the respective ends of the core 30 are loaded in a direction normal to the longitudinal axes of the core and the drum 14, this contour assists in producing the desired load profile along the full length of the nip 24. The desired load profile is determined empirically by optimizing performance with respect to media wrinkling and image uniformity across the page. In the present preferred embodiment, the optimum pressure profile is near uniform, with only an approximately 10% increase in pressure in the center of the roller as compared to the ends.
Surrounding the core 30 are three elastomeric layers: an inner elastomeric layer 32, a tubular elastomeric sleeve 36 and an outer compliant elastomeric layer 40. As described in more detail below, each of the three layers is preferably comprised of urethane for improved layer-to-layer bonding and greater fatigue resistance as compared to layers of dissimilar materials. As shown in FIG. 2, the inner elastomeric layer 32 is contoured to follow the contour of the core 30, with the thickness of the layer increasing from the center of the roller 20 toward each end. In this manner, the inner elastomeric layer 32 cooperates with the contoured core 30 to provide the desired pressure distribution by transferring the load balancing effect of the core to the nip 24. The inner elastomeric layer 32 also helps to offset other system imbalances, such as imbalanced end loads, varying ink image and media thicknesses and different part tolerances. Preferably, the inner elastomeric layer 32 is made from castable urethane with a durometer of between about 39 and about 49 Shore A, with the most preferred material having a durometer of 44 Shore A. A suitable urethane, identified as M44AXXTK, is available from the Mearthane Products Corporation of Cranston, R.I.
Affixed to an outer surface of the inner elastomeric layer 32 is a tubular elastomeric sleeve 36. In an important aspect of the present invention, the elastomeric sleeve 36 has a relatively high hardness or durometer to create a very narrow nip 24 (see FIG. 1) and a high localized pressure within the nip. In the preferred embodiment, the elastomeric sleeve 36 is made from castable urethane having a durometer of about 70 to about 85 Shore D, with the most preferred durometer being 80 Shore D. A suitable urethane, identified as M8ODXXTK, is available from Mearthane Products Corporation. Additionally, by utilizing urethane for both the inner elastomeric layer 32 and the elastomeric sleeve 36, a strong chemical bond is created between these components for superior durability as compared to an adhesive bond between dissimilar materials.
In another important aspect of the present invention, the preferred elastomeric sleeve 36, inner elastomeric layer 32 and contoured core 30 cooperate to create a very narrow nip, with the average nip width being between about 0.065 and about 0.075 inches (between about 1.651 mm and about 1.905 mm). Advantageously, this narrow nip concentrates the pressure created by the roller 20 within a localized area on the final receiving medium 22. In the preferred embodiment, this localization of pressure allows the roller 20 to create an average nip pressure of over about 1100 psi (7,584 kPa), and preferably a pressure of about 1150 psi (7,929 kPa). Additionally, this pressure is achieved with each end of the roller being loaded with less than about 600 pounds (lbs)(2,669 N.) per end, and preferably only approximately 550 lbs (2,446 N.) per end. In many prior art pressure rollers, a loading of between 400 and 600 lbs (1,779 and 2,669 N.) per end is necessary to create an average nip pressure of between 500 and 700 psi (3,447 and 4,826 kPa). Advantageously, the roller 20 of the present invention achieves significantly higher nip pressures with generally equivalent end loadings. Accordingly, the roller 20 may be incorporated into standard printing apparatus that are designed to accommodate roller loadings of up to 600 lbs (2,669 N.) per end.
As described above, the high nip pressure generated by the roller 20 of the present invention also allows for reduced medium and ink preheat temperatures as compared to prior art printing apparatus that generate much lower nip pressures. This is possible because the increased nip pressure provides added mechanical energy to compensate for the reduced thermal energy (ink/media temperatures). This added energy is necessary for adequate image durability and transfer from the intermediate surface. Advantageously, the lower ink and media temperatures allow the printer to duplex without smearing the duplexed image or wrinkling the medium. These lower temperatures also reduce the thermal energy requirements of the printing apparatus 10, making it more energy efficient.
As shown in FIGS. 2 and 3, the preferred embodiment of the elastomeric sleeve 36 includes a shoulder 38 near each end of the roller 20. The distance between the shoulders 38 corresponds to the largest imaging area, or the widest medium, that will be utilized with the printing apparatus 10. In one possible embodiment, the distance between the shoulders 38, and thus the widest possible imaging area, is about 13.6 inches (0.345 m.) and the overall length of the roller 20 is about 15.9 inches (0.404 m.). In this embodiment, the thickness of the sleeve 36 within the imaging area is approximately 0.100 inches (2.54 mm.). Advantageously, by incorporating the shoulders 38 at the edges of the widest possible medium to be used, the nip pressure is applied only to that portion of the roller 20 that engages the medium. This further reduces the end load requirements of the roller 20.
As described above, in prior art pressure rollers the desired nip pressures are typically achieved by utilizing a very rigid, high durometer outer layer on the roller. However, while a rigid outer layer increases the nip pressure, it also reduces the ability of the roller to conform to variations in media and ink image thickness. For example, where a single ink pixel having a first height is adjacent to one or more multiple layer ink pixels having a second greater height, a roller with a rigid outer layer is often unable to conform to contact the shorter single ink pixel. As illustrated in FIG. 4 of the present application, this problem is especially apparent where a single ink pixel 42 is "hidden" between two adjacent dual layer pixels 44, 46, in which case an insufficiently compliant roller cannot conform to reach the single "hidden" pixel. As a result, image transfer (in offset printing) and image fusing to the medium are reduced, and other parameters of the imaging process must be adjusted to maintain an acceptable image quality. Typically in these situations, the media preheat and ink temperatures are increased to improve image transfer and fusing.
To address and substantially overcome these problems of the prior art pressure rollers, the roller 20 of the present invention includes a thin outer compliant elastomeric layer 40 that is affixed to the elastomeric sleeve 36. FIGS. 4 and 5 illustrate the manner in which the outer compliant layer 40 of the roller 20 exhibits compliance across a two pixel span to improve the transfixing of ink pixels from an intermediate transfer surface to a final receiving medium.
With reference now to FIG. 4, the single ink pixel 42 is positioned between adjacent dual layer ink pixels 44, 46. Each of the pixels 42, 44, 46 is resting on the intermediate transfer surface 12. At this point in the transfix process, the two dual layer pixels 44, 46 are initially contacting an ink image receiving surface 52 of the final receiving medium 22 within the nip 24 before full nip pressure has been established. As shown in FIG. 4, a gap 48 exists between the top surface 50 of the single ink pixel 42 and the ink image receiving surface 52 of the final receiving medium 22.
With reference now to FIG. 5, the ability of the outer compliant layer 40 to conform within the diameter of the single ink pixel 42 is illustrated as the full nip pressure P is applied in the direction of action arrow P. More specifically, an outer surface 54 of the outer compliant layer 40 conforms to press the ink image receiving surface 52 downwardly to close the gap 48 of FIG. 4 and contact the "hidden" single ink pixel 42. Advantageously, in the preferred embodiment this improved compliance allows the roller 20 to transfix 100 percent of the ink pixels forming an ink image from the intermediate transfer surface 12 to the final receiving medium 22. In this manner, the outer compliant layer 40 advantageously provides a significant improvement in image transfer and overall image transfixing as compared to the rollers of the prior art. Furthermore, as shown in FIG. 5, an inner surface 56 of the outer compliant layer 40 remains substantially rigid when under full loading. In this manner, the full nip pressure P is transmitted on a macro level along the entire nip 24 through the outer compliant layer 40 to the final receiving medium 22 for optimal image fusing. Alternatively expressed, and to summarize an important aspect of the present invention, the outer compliant layer 40 cooperates with the rigid elastomeric sleeve 36, inner elastomeric layer 32 and core 30 to a create a high nip pressure on a macro level along the entire nip 24 while simultaneously exhibiting compliance on a micro/pixel-to-pixel level for optimal image transfer and fusing.
To achieve the above performance characteristics, the preferred material for the outer compliant elastomeric layer 40 is castable urethane having a durometer of between approximately 80 and approximately 90 Shore A, with the most preferred durometer being approximately 85 Shore A. A suitable urethane, identified as M85AXXTK, is available from Mearthane Products Corporation. The preferred thickness of the outer compliant elastomeric layer 40 is between approximately 0.010 and approximately 0.020 inches, with the most preferred thickness being 0.015 inches. The preferred hardness and thickness allow the outer compliant elastomeric layer 40 to deflect at least 0.001 inches under a load of approximately 1150 psi to contact a single layer ink pixel hidden between adjacent dual layer pixels. Additionally, the outer surface 54 of the outer compliant elastomeric layer 40 preferably has a surface finish of approximately 16×10 -6 inches (4×10 -4 mm.) or better to maintain uniform pressure over porous media surfaces. The preferred urethane construction of the outer compliant layer 40 also provides a superior chemical bond with the adjacent urethane sleeve 36 to withstand the shear stresses and other forces created by the high nip pressure of the roller 20.
In summary, the pressure roller 20 of the present invention combines rigidity for high nip pressure with compliance for superior image transfer and fusing and improved nip pressure uniformity. These benefits of the roller are achieved with lower media and ink temperatures that allow for duplex printing and reduce media wrinkling. The roller also utilizes three urethane layers for improved layer-to-layer bonding and greater fatigue resistance.
The foregoing description of a preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many changes, modifications, and variations in the materials and arrangement of parts can be made, and the invention may be utilized with various different printing apparatus, all without departing from the inventive concepts disclosed herein. The preferred embodiment was chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as is suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with breadth to which they are fairly, legally, and equitably entitled. All patents cited herein are incorporated by reference in their entirety. | A roller for applying pressure to a final receiving medium to transfer and fix an ink image thereon is provided. The roller includes a core surrounded by an inner elastomeric layer. A tubular elastomeric sleeve having a first, relatively high hardness surrounds the inner elastomeric layer. A thin outer compliant elastomeric layer is affixed to the outer surface of the sleeve and has a second hardness that is less than the first hardness of the sleeve. The outer compliant elastomeric layer of the roller has sufficient compliance to contact adjacent ink pixels having first and second heights and fix the ink pixels to the final receiving medium. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to implantable medical devices, and more specifically, relates to chronically implantable devices for determination of a plurality of hemodynamic variables including but not limited to right atrial pressure and pulmonary arterial pressure.
2. Description of the Prior Art
Intravascular pressure sensors are known in the art. U.S. Pat. No. 4,407,296 issued to Anderson teaches a chronically implantable pressure transducer suitable for use in the cardiovascular system. A pressure transducer with an improved electronic circuit is taught in U.S. Pat. No. 4,432,372, issued to Monroe. A further improved pressure transducer is taught in U.S. Pat. No. 4,485,813, issued to Anderson et al. These pressure sensors have been directed to the control of artificial cardiac pacers using algorithms which convert measurements of pressure or change of pressure into pacing rate.
Increases in the complexity of pacemakers and other implantable medical devices have increased efforts at producing sensors and transducers to monitor a variety of physiologic functions. Such transducers allow the exploitation of the additional capability of such medical devices.
The measurements of pressures (particularly pulmonary wedge pressure and central venous pressure) inside the heart are typically used to determine the health of the patient and provide a proper therapy. A number of restrictions are placed on defining the approach to a chronically implantable pressure sensor. Three of these restrictions are:
(1) it is generally unacceptable to implant any hardware on the left side of the heart, so pressures are normally measured from the right side,
(2) a chronic wedge pressure measurement is unacceptable due to pulmonary infarction, and
(3) chronically implanted leads in the pulmonary artery have not yet been proven to be safe.
One system for treating a malfunctioning heart based on hemodynamics i.e., the pressure at a site in a patient's circulatory system is taught in U.S. Pat. No. 4,986,270 issued to Cohen.
None of these references teaches the use of a single chronically implanted absolute pressure sensor in the right ventricle for determining a plurality of hemodynamic variables, i.e., right atrial pressure, right ventricular pressure, and pulmonary arterial pressure in a patient.
SUMMARY OF THE INVENTION
The present invention is a method and apparatus to determine the hemodynamic status of a patient from measurements of pulmonary pressure and right atrial pressure obtained from a single absolute pressure sensor implanted in the right ventricle. Both of these values have been shown to correlate with the degree of cardiac failure of a patient. The inventive technique employs continual monitoring of the right ventricular pressure using an absolute pressure sensor and marking the right ventricular pressure at the moment of specific events.
When the pulmonary valve is open during right ventricular systole, the pressure in the right ventricle is nearly identical to the pulmonary arterial pressure. Therefore, pulmonary artery systolic pressure equals right ventricle systolic pressure. This pressure can be determined using the right ventricular pressure by: pulmonary artery (PA) systolic pressure=right ventricle (RV) pressure at the time dP Rv /dt=0 during ventricular systole.
The pulmonary artery diastolic pressure is similarly determined from the right ventricle. As long as the pulmonary artery pressure is higher than the right ventricle pressure, the pulmonary valve is closed. As the ventricle begins to contract during systole, however, the right ventricle pressure surpasses the pulmonary artery pressure and the valve opens. The pressure in the pulmonary artery at the time the valve opens is the lowest pressure seen by the pulmonary artery and, therefore, is the pulmonary artery diastolic pressure. Thus, the pulmonary artery diastotic pressure is the pressure in the right ventricle at the moment the pulmonary artery valve opens. The time at which the valve opens has been shown to be nearly identical to the time of maximum dPRv/dt. Therefore, in one preferred embodiment, the pulmonary artery diastolic pressure can be determined using right ventricular pressure by: PA diastolic pressure=RV pressure at the time d 2 P RV /dt 2 =0 at the start of systole.
In another preferred embodiment, the pulmonary artery diastolic pressure can be determined directly using right ventricular pressure at the requisite moment determined with the aid of ultrasound measurements.
In a further preferred embodiment, the pulmonary artery diastolic pressure can be determined with the aid of acoustic signature measurements to determine the precise moment in time that the right ventricular pressure is equivalent to the pulmonary artery diastolic pressure.
In yet another preferred embodiment, the precise moment for determining the validity of the pulmonary artery diastolic pressure can be determined by impedance change measurements performed on the patient.
From the above discussion, it is apparent that numerous ways and methods can be used to determine the precise moment in time when the pulmonary valve opens. Therefore, the present invention, although discussed in terms relating to calculation of derivatives of ventricular pressure measurements, is not so limited.
Right atrial systolic and diastolic pressure can also be determined from an absolute pressure sensor in the right ventricle with the present inventive apparatus and method. This is possible because the valve between the right atrium and right ventricle is open at all times except during right ventricular contraction. Therefore, the atrial diastolic pressure is the same as the right ventricular pressure just prior to atrial contraction (atrial pulse or P-wave sense). Atrial systolic pressure can be determined in much the same way as pulmonary artery systolic pressure. In this case however, the inventive apparatus must find dP/dt=0 after the start of atrial systole.
The present invention is applicable anywhere that the measurement of hemodynamic status is important, and includes, but is not limited to the diagnosis of the severity of congestive heart failure, pulmonary artery disease, and pulmonary hypertension or the measurement of hemodynamic variables like vascular resistance, contractility, etc. For example, the maximum dP/dt signal derivation capability of the present invention can also approximate contractility; and the RV diastolic pressure in combination with mean arterial pressure (e.g. measured by a cuff) and a separate measure of cardiac output (measured either invasively or noninvasively) can provide a measure of vascular resistance.
Other features and advantages of the present invention will be set forth in, or become apparent from, the following description and claims and illustrated in the accompanying drawings, which disclose by way of example and not by way of limitation, the principle of the invention and the structural implementation of the inventive concept. For example, the present invention can be used to control devices that provide therapy i.e., cardiac pacemakers, defibrillators or drug pumps.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially block, schematic diagram of a control system, responsive to a right ventricular pressure sensor signal, an ECG R-wave signal and an ECG P-wave signal.
FIG. 2 is a block diagram of an implantable telemetry system which incorporates the control system of FIG. 1.
FIG. 3 is a diagrammatic, generalized illustration of an exemplary, right ventricular, implanted absolute pressure sensor and an associated telemetry device such as that illustrated in FIG. 2.
FIG. 4 is an illustration of an absolute pressure sensor positioned within a heart.
FIG. 5A illustrates a typical ECG signal.
FIG. 5B illustrates a typical right ventricular pressure signal.
FIG. 5C illustrates a signal derived from the derivative of the signal depicted in FIG. 5B, and which can be used to determine pulmonary artery systolic pressure as well as right atrial systolic and diastolic pressure.
FIG. 5D illustrates a signal derived from the derivative of the signal depicted in FIG. 5C, and which can be used to determine pulmonary artery diastolic pressure.
FIG. 6A illustrates an actual patient cardiac waveform of an ECG signal.
FIG. 6B illustrates actual patient cardiac waveforms of pulmonary artery pressure and right ventricular pressure signals.
FIG. 6C illustrates a waveform resulting from the derivative (dP/dt) of the right ventricular pressure signal depicted in FIG. 6C.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Starting generally with FIG. 1, there is depicted one embodiment of a pressure sensing circuit 10 which forms part of an implantable monitoring device 302 illustrated in FIG. 3 and used for determining the hemodynamic status of a patient. It is to be understood that device 302 is contained within a hermetically-sealed, biologically inert outer shield or "can", in accordance with common practice in the art. The sensing circuit 10 is operable in conjunction with an implantable absolute pressure sensor 402 which is implanted in the patient's right ventricle as depicted in FIG. 4. Implantable monitoring device 302 includes pressure sensing circuit 10 as well as additional control, power, memory and transmission circuitry illustrated in FIG. 2 and hereinafter discussed in detail.
Operation of the implantable monitoring device 302 will now be discussed in more detail with reference to FIGS. 1-6. As stated hereinbefore, the measurements of pressures, particularly pulmonary wedge pressure inside the heart are typically used to determine the health of a patient and provide a proper therapy. One illustrative method for determining pulmonary artery and right arterial diastolic and systolic pressure begins with reference to the simplified block diagram of pressure sensing circuit 10 illustrated in FIG. 1. The basic functional components are differentiators 40,42, comparators 36,38,44, sample-and-holds 32,34,46,50, and delays 30,48. Embodiment 10 also requires the output 14 from an R-wave sense amplifier (not illustrated in FIG. 1) and the output 16 from a P-wave sense amplifier (not illustrated in FIG. 1), but known to those skilled in the art of cardiac pressure monitoring.
Operation of the preferred embodiment 10 shown in FIG. 1 begins by twice differentiating the signal 12 from an absolute pressure sensor 402 which is chronically .implanted in the right ventricle, to provide dP/dt and d 2 P RV /dt 2 . A typical ECG signal is illustrated in FIG. 5A while its associated right ventricular (RV) pressure sensor waveform 12 is shown in FIG. 5B. Differentiator 40 provides an output signal 502 illustrated in FIG. 5C which is the first derivative of waveform 12. Differentiator 42 provides an output signal 504 illustrated in FIG. 5D which is the second derivative of waveform 12.
Looking at the waveforms shown in FIGS. 5A-5D, it can be seen that the maximum RV (and PA) systolic pressure occurs the first time after the R-wave 506 that dP/dt 502 goes negative (passes through zero). It follows (from the discussion above) that the maximum dP/dt (PA diastolic pressure) occurs the first time after the R-wave 506 that d 2 P RV /dt 2 504 goes negative.
FIG. 6A illustrates an actual human cardiac ECG waveform. The ECG P-wave 602 and R-wave 604 are obvious.
Looking now at FIG. 6B, actual cardiac waveforms of a patient's pulmonary artery (PA) pressure and right ventricular (RV) pressure are illustrated. From FIG. 6B it can be seen that the PA diastolic pressure (minimum PA) occurs at nearly the same pressure where the PA pressure and RV pressure signals cross each other.
FIG. 6C is the dP/dt waveform 606 resulting from a first derivative of the patient's RV pressure signal 12. It is important here to note that the peak of dP/dt waveform 606 occurs at the same time that the PA pressure 18 equals the RV pressure 12.
Referring again to FIG. 1, the PA systolic pressure 22 is determined by feeding the RV pressure sensor output 12 into a sample and hold circuit 34. The sample and hold circuit 34 is enabled by the sensing of the R-wave 506 shown in FIG. 5A. The systolic pressure 22 is then latched when dP/dt 502 illustrated in FIG. 5C goes negative as determined by comparator 36 output signal 28. This value of systolic pressure will be held until the next R-wave 506 is sensed, enabling the sample and hold circuit 34 to change values.
Similarly, the PA diastolic pressure is determined by feeding the RV pressure 12 into a sample and hold circuit 32 which is latched by comparator 38 the first time that d 2 P RV /dt 2 504 illustrated in FIG. 5D goes negative after a sensed R-wave 506. In this case, a short delay 30 in the pressure signal path balances the electronic delays in the two signal paths, keeping the timing synchronized.
From the above description of the present invention, it is apparent that numerous pressure readings other than those described hereinbefore, can be obtained with the present invention. For example, the present invention can be used to obtain right ventricular systolic and diastolic maximum dP/dt, etc.
Measurement of atrial pressures can also be accomplished similarly as follows. The right atrial (RA) systolic pressure 24, like PA systolic pressure 22, is latched by a sample and hold circuit 46. Unlike PA pressure measurements however, latching occurs the first time that dP/dt 502 passes through zero subsequent to detection of a P-wave 508 as depicted in FIG. 5A. RA diastolic pressure 20 is determined in the preferred embodiment shown in FIG. 1 by latching the RV pressure 12 at a time (eg. 100 msec) before the RA systolic pressure 24 measurement of interest. This is accomplished by delaying the RV pressure signal 12 with a delay circuit 48, and then latching the delayed signal with a sample and hold circuit 50 upon detection of a p-wave 508.
The preferred embodiment 10 described hereinbefore and illustrated in FIG. 1 is shown as pressure sensing circuit 10 in FIG. 2. Turning now to FIG. 2, there is illustrated in block diagram form, a complete implantable pressure telemetry system 200 for measurement and transmission of patient pulmonary and venous pressure values to an external communication device.
Although a particular implementation of a pulmonary and venous pressure measurement and telemetry system 200 is disclosed herein, it is to be understood that the present invention may be advantageously practiced in conjunction with many different types of telemetry systems.
Telemetry circuit 202 is schematically shown in FIG. 2 to be electrically coupled via P-wave/R-wave sensor leads 240,246 and RV pressure sensor leads 404,406 to a patient's heart 400. Leads 240,246,404,406 can be of either the unipolar or bipolar type as is well known in the art; alternatively, a single, multiple-electrode lead may be used.
Telemetry system 200 contains the analog circuits 202 for interface to the heart 400, an antenna 230, and circuits (not shown, but conventional to those skilled in the art) for the detection of pressure signals from the heart
It will be understood that each of the electrical components represented in FIG. 2 is powered by an appropriate implantable battery power source 206, in accordance with common practice in the art. For the sake of clarity, the coupling of battery power to the various components of telemetry circuit 202 has not been shown in the Figures.
An antenna 230 is connected to telemetry circuit 202 for purposes of uplink/downlink telemetry through an RF transmitter and receiver unit 224. Unit 224 may correspond to the telemetry and program logic employed in U.S. Pat. No. 4,556,063 issued to Thompson et al. on Dec. 3, 1985 and U.S. Pat. No. 4,257,423 issued to McDonald et al. on Mar. 24, 1981, both of which are incorporated herein by reference in their entirety. Telemetering analog and/or digital data between antenna 230 and an external device, such as the aforementioned external communication device (not shown in FIG. 2), may be accomplished in the presently disclosed embodiment by means of all data first being digitally encoded and then pulse-position modulated on a damped RF carrier, as substantially described in U.S. Pat. No. 5,127,404 issued to Wyborny et al entitled "Improved Telemetry Format", which is assigned to the assignee of the present invention and which is incorporated herein by reference in its entirety.
A crystal oscillator circuit 228, typically a 32,768 Hz crystal-controlled oscillator, provides main timing clock signals to digital controller/timer circuit 216. A V REF and Bias circuit 220 generates stable voltage reference and bias currents for the telemetry system 200 analog circuits. An analog-to-digital converter (ADC) and multiplexer unit 222 digitizes analog signals and voltages to provide "real-time" telemetry communication signals and battery end-of-life (EOL) replacement functions. A power-on-reset (POR) circuit 226 functions as a means to reset circuitry and related functions to a default condition upon detection of a low battery condition, which will occur upon initial device power-up or will transiently occur in the presence of electromagnetic interference, for example.
The timing functions of telemetry system 200 are controlled by event timer 204 in conjunction with digital controller/timer circuit 216 wherein digital timers and counters are employed to establish the overall event timing of the telemetry system 200, including timing windows for controlling the operation of the peripheral components within telemetry circuit 202.
Event timer 204 monitors the pressure event signals received from heart 400 by pressure sensing circuit 10, and handshakes with digital controller/timer circuit 216 on a bidirectional bus 208 to synchronize measurement of and rf transmission of the desired pressure signal values to an external communication device.
Digital controller/timer circuit 216 is coupled to pressure sensing circuit 10. In particular, digital controller/timer circuit 216 receives PA diastolic signal 18 on line 232, PA systolic signal 22 on line 234, RA diastolic signal 20 on line 238 and RA systolic signal 24 on line 226. P-wave and R-wave sense amplifiers (not shown) are coupled to leads 240 and 246, in order to receive ECG signals from heart 400. The sense amplifiers correspond, for example, to that disclosed in U.S. Pat. No. 4,379,459 issued to Stein on Apr. 12, 1983, incorporated by reference herein in its entirety.
Sense amplifier sensitivity control (also not shown) is provided to adjust the gain of sense amplifier circuitry in accordance with programmed sensitivity settings, as would be appreciated by those of ordinary skill in the pacing art.
While a specific embodiment of pressure sensing circuit 10 has been identified herein, this is done for the purposes of illustration only. It is believed by the inventor that the specific embodiment of such a circuit is not critical to the present invention so long as it provides means for temporarily storing PA and RA systolic and diastolic pressures and providing digital controller/timer circuit 216 with signals indicative of PA and RA systolic and diastolic pressures accordingly. It is also believed that those of ordinary skill in the art could choose from among the various well-known implementations of such circuits in practicing the present invention.
While the invention has been described above in connection with the particular embodiments and examples, one skilled in the art will appreciate that the invention is not necessarily so limited. It will thus be understood that numerous other embodiments, examples, uses, modifications of, and departures from the teachings disclosed may be made, without departing from the scope of the present invention as claimed herein. | A method and apparatus for monitoring and measuring the hemodynamic status of a patient's pulmonary pressure and right atrial pressure. The aforementioned is achieved by using an implanted absolute pressure sensor located in the right ventricle, coupled to an implantable monitoring device, which records pressure values in response to a combination of sensed electrical depolarizations of the atrium and ventricle and occurrence of first and second derivatives of the pressure signal having values less than zero. | 0 |
This application claims benefit under 35 U.S.C. §119(e) from U.S. provisional patent application Ser. No. 60/371,718 entitled “A System And Method For Identifying Potential Hidden Node Problems in Multi-Hop Wireless Ad-Hoc Networks For The Purpose Of Avoiding Such Potentially Problem Nodes In Route Selection”, filed Apr. 12, 2002, the entire contents of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a system and method for identifying potential hidden node problems in a multi-hop wireless ad-hoc communication network, such as an 802.11 network. More particularly, the present invention relates to a system and method for identifying nodes of a wireless ad-hoc communication network whose capabilities of receiving data packets can be adversely affected by hidden node problems, in order to avoid selecting paths containing those potentially problem nodes for routing data packets.
2. Description of the Related Art
In recent years, a type of mobile communications network known as an “ad-hoc” network has been developed. In this type of network, each user terminal (hereinafter “mobile node”) is capable of operating as a base station or router for the other mobile nodes, thus eliminating the need for a fixed infrastructure of base stations. Accordingly, data packets being sent from a source mobile node to a destination mobile node are typically routed through a number of intermediate mobile nodes before reaching the destination mobile node.
More sophisticated ad-hoc networks are also being developed which, in addition to enabling mobile nodes to communicate with each other as in a conventional ad-hoc network, further enable the mobile nodes to access a fixed network and thus communicate with other types of user terminals, such as those on the public switched telephone network (PSTN) and on other networks such as the Internet. Details of these types of ad-hoc networks are described in U.S. patent application Ser. No. 09/897,790 entitled “Ad Hoc Peer-to-Peer Mobile Radio Access System Interfaced to the PSTN and Cellular Networks”, filed on Jun. 29, 2001, in U.S. patent application Ser. No. 09/815,157 entitled “Time Division Protocol for an Ad-Hoc, Peer-to-Peer Radio Network Having Coordinating Channel Access to Shared Parallel Data Channels with Separate Reservation Channel,” filed on Mar. 22, 2001, now U.S. Pat. No. 6,807,165, and in U.S. patent application Ser. No. 09/815,164 entitled “Prioritized-Routing for an Ad-Hoc, Peer-to-Peer, Mobile Radio Access System”, filed on Mar. 22, 2001, now U.S. Pat. No. 6,873,839 the entire content of each of said patent applications being incorporated herein by reference.
As can be appreciated by one skilled in the art, when a node sends packetized data to a destination node, the node typically checks its routing table to determine whether the destination node is contained in its routing table. If the destination node is contained in the node's routing table, the data is transmitted via a path that leads to the destination node. If the destination node is not listed in the node's routing table, then the packet is sent to one or more other nodes listed in the node's routing table, and those other nodes determine if the destination table is listed in their routing tables. The process continues until the data packet eventually reaches the destination node.
As can further be appreciated by one skilled in the art, the “hidden node” problem is a classic problem for Medium Access Protocols (MACs) in these types of ad-hoc networks. The problem occurs when two radios (nodes) are transmitting outside the effective communication range of each other, but both are within the effective communication range of an intermediate node that is also participating in the network. If both of the two radios in the network attempt to communicate with the intermediate node at or near the same time, their signals can collide and/or cause packet corruption at the intermediate node which is the intended receiver. In this case, the two extremal nodes are “hidden” from each other.
The hidden node problem therefore reduces successful packet delivery at the intermediate node. Also, the more hidden nodes there are around the intermediate node, the more severe the packet corruption can be.
Accordingly, a need exists for a system and method for effectively and efficiently identifying nodes experiencing hidden node problems in a wireless ad-hoc communication network, so that routing through those nodes can be avoided if possible.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a system and method for effectively and efficiently identifying nodes experiencing hidden node problems in a wireless ad-hoc communication network.
Another object of the present invention is to provide a system and method for locating and evaluating multiple neighbor node sets for each node, and calculating a degree of hidden nodes present at each node.
Still another object of the present invention is to provide a system and method for communicating a degree of hidden nodes present at each node as a routing advertisement for use in transmission route selection.
Still another object of the present invention is to provide a system and method for calculating at least one transmission route through a network avoiding nodes which advertise a high degree of hidden nodes present.
These and other objects of the present invention are substantially achieved by providing a system and method for identifying potential hidden node problems in a multi-hop wireless ad-hoc communication network, such as an 802.11 network. The system and method evaluates the relationship between the neighbors of each respective node to identify nodes of a wireless ad-hoc communication network whose capabilities of receiving data packets can be adversely affected by hidden node problems, in order to avoid selecting paths containing those potentially problem nodes for routing data packets.
Specifically, for each node, the system and method generates a node metric identifying the relationship between the neighbors of a node. A first neighbor node set is calculated for a node of interest, and thereafter, a neighbor node set is then calculated for each node included in the first neighbor node set. Nodes present in the first neighbor node set, but not present in each subsequent neighbor node sets, respectively, are included in a set of potentially hidden nodes about the node of interest. This value can be communicated with other nodes as a metric in a routing advertisement, so that other nodes can assess the degree of potential hidden node problems that may be experienced by that node, and can choose to avoid using that potentially problem node for routing data packets to other nodes.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects, advantages and novel features of the invention will be more readily appreciated from the following detailed description when read in conjunction with the accompanying drawings, in which:
FIG. 1 is a conceptual block diagram of an example of an ad-hoc wireless communications network employing a system and method for identifying the degree of hidden node problems that may be experienced by the respective nodes in the network according to an embodiment of the present invention;
FIG. 2 is a block diagram illustrating an example of components of a node employed in the network shown in FIG. 1 ;
FIG. 3 is a conceptual diagram depicting an example of the relationship between a node and its neighboring nodes in the network shown in FIG. 1 to demonstrate an example of the technique for evaluating the degree of potential hidden node problem that may be experienced by that node according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a block diagram illustrating an example of an ad-hoc packet-switched wireless communications network 100 employing an embodiment of the present invention. Specifically, the network 100 includes a plurality of mobile wireless user terminals 102 - 1 through 102 - n (referred to generally as nodes or mobile nodes 102 ), and a fixed network 104 having a plurality of access points 106 - 1 , 106 - 2 , . . . 106 - n (referred to generally as nodes or access points 106 ), for providing the nodes 102 with access to the fixed network 104 . The fixed network 104 includes, for example, a core local access network (LAN), and a plurality of servers and gateway routers, to thus provide the nodes 102 with access to other networks, such as other ad-hoc networks, the public switched telephone network (PSTN) and the Internet. The network 100 further includes a plurality of fixed routers 107 - 1 through 107 - n (referred to generally as nodes or fixed routers 107 ) for routing data packets between other nodes 102 , 106 or 107 .
As can be appreciated by one skilled in the art, the nodes 102 , 106 and 107 are capable of communicating with each other directly, or via one or more other nodes 102 , 106 or 107 operating as a router or routers for data packets being sent between nodes 102 , as described in U.S. Pat. No. 5,943,322 to Mayor, which is incorporated herein by reference, and in U.S. patent application Ser. Nos. 09/897,790, 09/815,157, now U.S. Pat. No. 6,807,165; and Ser. No. 09/815,164, now U.S. Pat. No. 6,873,839: referenced above. Specifically, as shown in FIG. 2 , each node 102 , 106 and 107 includes a transceiver 108 which is coupled to an antenna 110 and is capable of receiving and transmitting signals, such as packetized data signals, to and from the node 102 , 106 or 107 , under the control of a controller 112 . The packetized data signals can include, for example, voice, data or multimedia.
Each node 102 , 106 and 107 further includes a memory 114 , such as a random access memory (RAM), that is capable of storing, among other things, routing information pertaining to itself and other nodes 102 , 106 or 107 in the network 100 . In addition, certain nodes, especially nodes 102 , can include a subscriber device host (not shown), which can consist of any number of devices, such as a notebook computer terminal, mobile telephone unit, mobile data unit, personal computer (PC), personal data assistant (PDA), or any other suitable device.
In addition to, voice, data and multimedia packetized data signals, the nodes 102 , 106 and 107 exchange respective routing information, referred to as routing advertisements or routing table information, with each other via a broadcasting mechanism periodically, for example, when a new node 102 enters the network 100 , or when existing nodes 102 in the network 100 move. A node 102 , 106 or 107 will broadcast it's routing table updates, and nearby nodes 102 , 106 or 107 will only receive the broadcast routing table updates if within broadcast range (e.g., radio frequency (RF) range) of the broadcasting node 102 , 106 or 107 . For example, assuming that nodes 102 - 1 and 102 - 6 are within the RF broadcast range of node 102 - 3 , when node 102 - 3 broadcasts routing table information, the current table information is received and filed by both nodes 102 - 1 and 102 - 6 . However, if nodes 102 - 2 , 102 - 4 and 102 - 5 are beyond the broadcast range of node 102 - 3 , these nodes will not receive the current table information broadcast.
Each node 102 , 106 or 107 in the network 100 can also experience the hidden node problem as discussed in the Background section above. As will now be discussed with regard to FIG. 3 , an embodiment of the present invention provides a technique for identifying the degree of the potential hidden node problem that can be experienced by a node 102 , 106 or 107 , such that other nodes 102 , 106 and 107 can avoid including such nodes in selected routing paths for routing data packets through the network 100 .
According to an embodiment of the present invention, the wireless ad-hoc network 100 may use certain metrics to avoid degenerate areas of the network demonstrating decreased performance. Optimally, a multi-hop ad-hoc routing network 100 can be configured so that a routing path chosen from a source node to a destination node will ensure the highest bandwidth, lowest latency, and greatest probability for packet delivery. The embodiment of the present invention enables the nodes of network 100 to establish a routing metric, which prevents the nodes from routing packets through areas of the network 100 that contain high degrees of hidden nodes. For this embodiment, the descriptive term “degree of hidden nodes” at a node of interest refers to the number of hidden nodes present about the node.
As discussed above, in a multi-hop wireless ad-hoc routing network 100 , a routing advertisement transmitted by a node 102 , 106 and 107 may advertise all of the other nodes 102 , 106 and 107 , or neighbor nodes, with which that node can directly communicate. In addition, the routing advertisement transmitted by a node 102 , 106 and 107 typically advertises all of the destinations that can be reached from the node directly, and destinations that can be reached indirectly, listing the intermediate nodes to which the packet must be delivered to in order to reach the destination. As will now be described, an embodiment of the present invention examines the neighbor node routing advertisements transmitted by a node to evaluate the potential hidden problem experienced by that node.
FIG. 3 is a conceptual diagram illustrating an exemplary relationship 116 between four nodes, consisting of any combination of nodes 102 , 106 and 107 , in the network 100 , which are identified as nodes a, b, c and d. The lines between the nodes a, b, c and d indicate a neighbor relationship. For example, node a is neighbors with nodes b and c, node b is neighbors with nodes a and c, node d is neighbors with node c, and node c is neighbors with nodes a, b and d. The set of neighbors of node a is indicated as set A. The entity a is included in the list of neighbors indicated in set A. So for the portion of the network 100 shown in FIG. 3 , the neighbor lists of each node are:
A={a,b,c} B={a,b,c} C={a,b,c,d} D={c,d}
If we consider node c as the node of interest, an example of the technique of identifying the hidden nodes about node c according to an embodiment of the present invention is as follows:
First, the embodiment of the present invention identifies all of the nodes that are neighbors to the node of interest, node c, based on the routing advertisements transmitted by node c, which in this case, includes the node set C. For each neighbor node, a comparison is made between the routing advertisements transmitted by node c and the neighbor lists at each neighbor node. Specifically, as the neighbor list is received from node c at node a, Set A is compared with Set C. As the neighbor list is received from node c at node b, Set B is compared with Set C, and as the neighbor list is received from node c at node d, Set D is compared with Set C. Based upon each comparison, the nodes of each set not shared is then determined. This is the symmetric difference of each set comparison which in this example, is as follows:
C⊕A={d}
C⊕B={d}
C⊕D={a,b}
The union of these sets represents all of the potentially hidden nodes of node c. This set of potentially hidden nodes of node c for the network shown above is known as Pc, and it contains:
Pc={a,b,d}
The number of elements in the set is the determined, which in this example is determined as |Pc|=3, which represents the number of potentially hidden nodes of node c for the network.
All elements of the potentially hidden node set Pc which are neighbors of each other, or sub-neighbors, are then determined. In this example, nodes a, b and d are elements of the potentially hidden node set Pc. Of nodes a, b and d, only nodes a and b are sub-neighbors. These nodes are now treated as a single entry a_b in the new set of hidden nodes around node c:
Hc={a_b, d}
so |Hc|=2
Therefore, the degree of hidden nodes about node c is 2.
Since nodes a, b and c are all neighbors of each other, normal coordination can occur between them and they should not attempt to access the medium simultaneously. Therefore, the hidden node contribution made by nodes a and b is reduced to the hidden node contribution of a single node since they are coordinated. The degree of hidden nodes about c (i.e. 2) represents the number of mobile nodes, or radios, that are unaware of each other and which may cause interference at node c.
In the embodiment of the present invention described above, the degree of hidden nodes of each node 102 , 106 and 107 in the network 100 is determined in the manner described above. Each node then advertises it's respective metric along with its other routing information in the manner described above. Routing algorithms performed by, for example, the controller 112 of each of the nodes, can use the metric of each node to select transmission paths comprised of nodes having lower degrees of hidden nodes. This will thus minimize the likelihood that the packet will be corrupted or delayed due to the contribution of a hidden node along the route.
As can be appreciated from the above, the embodiment of the present invention can identify and help avoid routes in wireless ad-hoc routing networks that may be degenerate due to a large degree of hidden nodes along the route, as opposed to previous techniques which focused on direct measures of link quality among routes. The embodiment of the present invention can therefore predict areas of high hidden node interference in networks containing radios that cannot directly evaluate link quality.
In addition, some radio standards in use by mobile node, such as 802.11, may perform much more poorly than other standards in the presence of a high degree of hidden nodes. Specifically, the 802.11 standard, while in ad-hoc power-save mode, can experience the inability or greatly diminished capacity to transmit data in the presence of hidden nodes. In such an event, traditional direct measurements of link quality may not reflect the full degenerate condition in existence along a chosen route. Thus, it may be possible for such an area to appear to have a high capacity when in fact the synergy between the ad-hoc power-save algorithm and the hidden nodes may prevent most traffic from being successfully forwarded through the area. However, since the embodiment of the present invention discussed above can specifically identify the areas having high degrees hidden nodes, a routing algorithm may use such determinations to avoid routes through such areas, even though the areas can appear to have high node capacity.
As can be appreciated by one skilled in the art, the embodiment of the present invention can be employed in other wireless routing networks that can suffer from the classic hidden node problem, as well as to 802.11 devices in peer-to-peer mode and any other wireless device that allows direct peer-to-peer communication.
Although only a few exemplary embodiments of the present invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the following claims. | A system and method for identifying potential hidden node problems in a multi-hop wireless ad-hoc communication network, such as an 802.11 network. The system and method evaluates the relationship between the neighbors of each respective node to identify nodes of a wireless ad-hoc communication network whose capabilities of receiving data packets can be adversely affected by hidden node problems in order to avoid selecting paths containing those potentially problem nodes for routing data packets. Specifically, for each node, the system and method generates a node metric identifying the relationship between the neighbors of a node. Each node can then transmit its respective metric with its routing advertisement data, so that other nodes can assess the degree of potential hidden node problem that may be experienced by that node, and can choose to avoid using that potentially problem node for routing data packets to other nodes. | 7 |
[0001] This application claims priority to U.S. Provisional Patent Application Ser. No. 60/658,640 filed on Mar. 4, 2005 entitled, “Electric Control System for a Pressure Control Device in a Hazardous Area” incorporated herein by reference for all purposes.
BACKGROUND OF INVENTION
[0002] High pressure valves, or chokes, are often positioned at the wellhead to control flow. There are three main types of chokes: manual chokes, which require the user to be physically in the manifold and operate the choke by hand as the gas flows through; hydraulic chokes, which allow the user to operate the choke remotely from the drilling floor or doghouse; and electric chokes, which also allow the user to operate the choke remotely and are able to perform consistently in varying environmental conditions as well as add digital capabilities to the choke.
[0003] At locations where oil or gas wells are being drilled, a number of flammable gases may be present, including mixtures of oxygen, methane, ethane, propane, hydrogen sulfide and others. Similar potentially dangerous environmental conditions exist in locations in which petroleum products are being recovered, refined or processed. Standardized classifications for various types of hazardous locations have been adopted and assigned by regulatory agencies according to the nature and type of hazard that is generally present or that may occasionally be present.
[0004] Because electrical components, by their nature, may generate heat and sparks sufficient to ignite a flammable gas or other flammable mixture under even normal operating conditions, such components must be carefully selected and installed when used in an area that is classified as hazardous. More specifically, the components must exceed certain minimum standards as to such characteristics as power consumption, operating temperature, current and voltage requirements, and energy storage capabilities. These standards are also established by regulatory authorities and vary depending upon the particular hazardous environment.
[0005] Chokes positioned at the wellhead are often located in areas that are classified as hazardous. As such, the use of electric chokes may be limited to uses where they are not at the wellhead or in a hazardous area. It would be an improvement to have an electric choke that could be used at the wellhead or in other hazardous areas.
SUMMARY
[0006] In one aspect, the present invention relates to an apparatus for controlling a choke assembly, wherein the choke assembly includes a housing having an inlet and an outlet in fluid communication with a wellbore, a fixed plate located between the inlet and the outlet and having an orifice therethrough for communicating fluid from the inlet to the outlet, a choke plate rotatably retained against the fixed plate and having an orifice therethrough, wherein the choke plate is rotatable to adjust a size of an orifice resulting from the relative positions of the orifice through the choke plate and the orifice through the fixed plate and is further rotatable to close the resulting orifice to prevent fluid communication therethrough. The apparatus may include an air source, an air purge system in fluid communication with the air source, a remote operating panel receiving data from at least one remotely located wellbore sensor, a local operating panel in electronic communication with the remote operating panel, and an actuator coupled to the assembly to control pressure within the wellbore. The remote operating panel may include an airtight housing in fluid communication with the air purge system, wherein air from the air purge system is circulated through the housing, a plurality of operator controls for manually controlling operation of the pressure control assembly, and a display for visually displaying values of data received from the wellbore sensor. The local operating panel may include an airtight panel housing in fluid communication with the air purge system, wherein air from the air purge system is circulated through the panel housing, and a local operator controller having an operator interface for receiving operator instruction input into the local panel, and operable to receive operator instructions from the remote panel and transmit operator instructions. The actuator may include a motor in an explosion-proof housing coupled to the choke plate and operable to adjust the orifice through the choke plate, wherein the motor receives electronic communication of the operator instructions transmitted by the local operator controller, and a position indicator coupled to the choke plate for sensing the orifice opening and providing feedback of the choke plate position to the motor.
[0007] In another aspect, the present invention relates to an apparatus for a plurality of choke assemblies, wherein each choke assembly includes a housing having an inlet and an outlet in fluid communication with a wellbore, a fixed plate located between the inlet and the outlet and having an orifice therethrough for communicating fluid from the inlet to the outlet, a choke plate rotatably retained against the fixed plate and having an orifice therethrough, wherein the choke plate is rotatable to adjust a size of an orifice resulting from the relative positions of the orifice through the choke plate and the orifice through the fixed plate and is further rotatable to close the resulting orifice to prevent fluid communication therethrough. The apparatus may include an air source, an air purge system in fluid communication with the air source, a remote operating panel receiving data from at least one remotely located wellbore sensor, a local operating panel corresponding to each choke assembly being controlled, wherein each local operating panel is in electronic communication with the remote operating panel, and an actuator corresponding to each choke assembly and coupled thereto. The remote operating panel may include an airtight housing in fluid communication with the air purge system, wherein air from the air purge system is circulated through the housing, a toggle switch for selecting one of the choke assemblies to be controlled, a plurality of operator controls for manually controlling operation of the selected choke assembly, and a display for visually displaying values of data received from the wellbore sensor. Each local operating panel may include an airtight panel housing in fluid communication with the air purge system, wherein air from the air purge system is circulated through the panel housing, and a local operator controller having an operator interface for receiving operator instruction input into the local panel, and operable to receive operator instructions from the remote panel and transmit operator instructions. The actuator may include a motor in an explosion-proof housing coupled to the choke plate and operable to adjust the orifice through the choke plate, wherein the motor receives electronic communication of the operator instructions transmitted by the local operator controller, and a position indicator coupled to the choke plate for sensing the orifice opening and providing feedback of the choke plate position to the motor.
[0008] In yet another aspect, the present invention relates to an apparatus for controlling pressure in a wellbore including a choke assembly, wherein the choke assembly includes a housing having an inlet and an outlet in fluid communication with the wellbore, a fixed plate between the inlet and the outlet having an orifice therethrough for communicating fluid from the inlet to the outlet, a choke plate rotatably retained against the fixed plate and having an orifice therethrough, wherein the choke plate is rotatable to adjust a size of an orifice resulting from the relative positions of the orifice through the choke plate and the orifice through the fixed plate and is rotatable to close the resulting orifice to prevent fluid communication therethrough. The apparatus may also include an air source, an air purge system in fluid communication with the air source, a remote operating panel receiving data from at least one remotely located wellbore sensor, a local operating panel in electronic communication with the remote operating panel, and an actuator coupled to the assembly to control pressure within the wellbore. The remote operating panel may include an airtight housing in fluid communication with the air purge system, wherein air from the air purge system is circulated through the housing, a plurality of operator controls for manually controlling operation of the pressure control assembly, and a display for visually displaying values of data received from the wellbore sensor. The local operating panel may include an airtight panel housing in fluid communication with the air purge system, wherein air from the air purge system is circulated through the panel housing, and a local operator controller having an operator interface for receiving operator instruction input into the local panel, and operable to receive operator instructions from the remote panel and transmit operator instructions. The actuator may include a motor in an explosion-proof housing coupled to the choke plate and operable to adjust the orifice through the choke plate, wherein the motor receives electronic communication of the operator instructions transmitted by the local operator controller, and a position indicator coupled to the choke plate for sensing the orifice opening and providing feedback of the choke plate position to the motor.
[0009] Other aspects and advantages of the claimed subject matter will be apparent from the following description and the appended claims.
DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a schematic of a control system for automatic pressure control.
[0011] FIG. 2 is a front view of a remote actuator panel.
[0012] FIG. 3 is a side view of a remote actuator panel.
[0013] FIG. 4 is a front view of a local panel.
[0014] FIG. 5 is a top view of the actuator with a cutaway view of a proximity switch guard.
[0015] FIG. 6 is a side view of the actuator with a cutaway view of the hand wheel section.
[0016] FIG. 7 is an end view of the actuator with the hand wheel removed to show the belt drive.
[0017] FIG. 8 is a cross sectional side view of a choke assembly.
[0018] FIGS. 9 A-C depict choke plate positioning with respect to a fixed opening.
[0019] FIG. 10 is a cross sectional view of the position indicator.
[0020] FIG. 11 is a schematic of a control system for dual choke valve pressure control including a second pressure control device.
DETAILED DESCRIPTION
[0021] In one aspect, embodiments disclosed herein are directed to an apparatus for controlling a pressure control device. In another aspect, embodiments disclosed herein are directed to an apparatus for controlling a ;luality of pressure control devices. In yet another aspect, embodiments disclosed herein are directed to an apparatus for controlling pressure of a fluid in a wellbore. In each embodiment disclosed, the apparatus meets the requirements of Class 1, Division 1 standards as established by the American Petroleum Institute (API) and published in the API “Recommended Practice for Classification of Locations for Electrical Installations at Petroleum Facilities,” API Recommended Practice 500 (RP500), First Edition, Jun. 1, 1991, specifically incorporated herein by this reference.
[0022] Referring to FIG. 1 , an apparatus for controlling a pressure control device is shown generally as 100 . The terms “pressure control device,” “pressure control assembly,” and “choke assembly” are used herein, interchangeably, to refer to an apparatus that is used to regulate the pressure in a wellbore.
[0023] Referring to FIG. 8 , the choke assembly 106 with which the apparatus 100 is to be used has a fluid inlet 108 and a fluid outlet 110 , which are typically oriented such that they are right angles. An actuator end 112 is located opposite the fluid outlet 110 . The fluid path between the fluid inlet 108 and the fluid outlet 110 is controlled by a rotatable choke plate 116 and a fixed plate 120 . As shown in FIGS. 9 A-C, in one embodiment, the rotatable choke plate 116 has a half-moon shaped aperture 118 through its surface and the fixed plate 120 , downstream from the choke plate 116 has a fixed aperture 122 through it. A fluid aperture 124 is defined when the choke plate aperture 118 and the fixed aperture 122 overlap to provide fluid communication through both apertures 118 and 122 , as may be seen in FIGS. 9B and 9C . As the choke plate 116 is rotated relative to the fixed aperture 122 the size of the fluid aperture 124 varies. In this embodiment, the choke plate 116 is rotatable between a full closed position, shown in FIG. 9A , and a full open position, shown in FIG. 9C . In one embodiment, an actuator fork 114 coupled to the choke plate 116 is rotated to rotate the choke plate 116 . Pressure within the wellbore is controlled and adjusted by varying the fluid aperture 124 through the choke assembly 106 .
[0024] Referring, again, to FIG. 1 , in one embodiment, the apparatus 100 includes a remote panel 130 , a local panel 150 , an actuator 170 , and at least one sensor 126 . In one embodiment, the remote panel 130 is located in a doghouse or on a drilling floor of a rig 103 . In one embodiment, the local panel 150 is located at a choke manifold 104 . In one embodiment, the local panel is located within 30 feet of the actuator 170 . The actuator 170 is coupled to the actuating end 112 of a choke assembly 106 . One or more sensors 126 are located within the wellbore 102 to measure predetermined parameters.
[0025] The remote panel 130 of the control system 100 is shown in FIGS. 2 and 3 . In one embodiment, the remote panel 130 includes a housing 132 within which controls 134 are included. In one embodiment, controls 134 include a speed dial, an open/close lever, a contrast, and/or a stroke reset switch. In one embodiment, analog gauges 136 are included to provide information to the operator regarding relevant conditions in the wellbore 102 . A digital display 138 provides data from one or more choke assemblies 106 to the operator. In one embodiment, the digital display 138 also provides visual menus to the operator. In one embodiment, menus guide an operator through calibration of the actuator controls and choke 106 adjustments. Referring to FIG. 3 , a plurality of electronic inputs 140 are included through housing 132 to provide input of electronic data from one or more sensor communication cables 128 connecting one or more sensors 126 to the remote panel 130 . A panel communication cable 142 also connects the local panel 150 to the remote panel 130 electronically.
[0026] Referring again to FIG. 1 , an air purge system 144 ensures that the remote panel 130 is safe for operation in an area that is classified as hazardous. An air source 146 provides air to the air purge system 144 . In one embodiment, the air source 146 for the air purge system 144 is from the rig. In another embodiment, the air source 146 is a separate air source dedicated to the apparatus 100 . The air purge system 144 is in fluid communication with the housing 132 of the remote panel 130 , which is airtight. The purge system 144 includes feed lines 148 and intake lines 149 to communicate air into and out of the housing 132 . The clean air provided to the remote panel 130 prevents any hazardous gases from entering the housing 132 .
[0027] The local panel 150 provides a secondary interface for an operator to control the choke assembly 106 . The local panel 150 has a local panel housing 158 .
[0028] Referring to FIG. 4 , in one embodiment, the local panel 150 includes one or more basic controls 156 . In this embodiment, the controls 156 allow the operator to operate the choke 106 from the local panel 150 . In one embodiment, basic controls 156 include an open/close lever. In this embodiment, the open/close lever allows the operator to electronically actuate the choke 106 from the manifold 104 . In one embodiment, no speed control is provided on the local panel 150 and the lever operates differently from the open/close lever on the remote panel 130 . In this embodiment, as the lever on the local panel 150 is moved to either an open or closed mark, the actuator 170 begins to rotate at a percentage of its maximum speed. The actuator rotation speed accelerates to full speed within a predetermined time allowing the operator to make fine tuned movements in short bursts and to also fully open/close the valve quickly. In another embodiment, a speed controller is provided on the local panel 150 .
[0029] In one embodiment, an electronic input 160 is included through the side of housing 158 to provide electronic data along a sensor communication cable 128 to the local panel 150 from a sensor 126 in the wellbore 102 . In one embodiment, a plurality of electronic inputs 160 are included through the side of housing 158 to provide electronic data to the local panel 150 from a plurality of sensors 126 in the wellbore 102 . In one embodiment, an electronic interface 160 is also included for the panel communication cable 142 between the local panel 150 and the remote panel 130 .
[0030] The air purge system 144 ensures that the local panel 150 is safe for operation in an area that is classified as hazardous. The purge system includes feed lines 148 and intake lines 149 to communicate air into and out of the local panel 150 through an air feed opening 162 and air discharge 164 , respectively, in local housing 158 . Local housing 158 is airtight to prevent the entry of hazardous gases.
[0031] In one embodiment, the local panel 150 includes an emergency stop button 152 . In this embodiment, actuation of the emergency stop button shuts off power to the actuator 170 , thereby providing a class A shutdown of the choke 106 .
[0032] In one embodiment, the local panel 150 includes a digital display 154 . In this embodiment, an operator can observe measurements taken by one or more sensors 126 .
[0033] The actuator 170 is shown in FIGS. 5-7 . The actuator 170 is coupled to the choke assembly 106 and provides an interface between the remote panel 130 and/or the local panel 150 and the choke assembly 106 . In one embodiment, the actuator 170 includes an actuator housing 172 , a hand wheel 240 , a motor 212 , a position indicator 188 , and a belt drive 220 . In one embodiment, the actuator housing 172 includes an adapter 174 , an actuator guard 176 , a motor housing 178 , a motor guard 180 , and a belt guard 182 and belt guard lid 184 .
[0034] The motor 212 is housed within the motor housing 178 , which is coupled to the belt guard 182 . To ensure that the motor 212 is safe for use in a hazardous area, the motor housing 178 is explosion proof. Further, a junction box 214 is provided to receive the control communication cable 166 from the local panel 150 and the switch communication cable 196 . The junction box 214 is also explosion proof, with the control and switch communication cable inputs 218 being armored. The control communication cable 166 and switch communication cable 196 are also armored to ensure they are safe for use in a hazardous area. The junction box 214 is attached to the motor housing 178 and such that the power and sensor feedback are connected to the motor 212 within an enclosure formed by the junction box 214 and the motor housing 178 . The motor 212 is connected to the belt drive 220 .
[0035] Referring to FIG. 7 , the belt guard 182 and the belt guard lid 184 form an enclosure within which the belt drive 220 is retained. In one embodiment, the belt drive 220 includes a first sprocket 222 , a second sprocket 230 , and a belt 238 . In this embodiment, the first sprocket 222 has a first diameter 224 and includes a first groove 226 around its side 228 . The second sprocket 230 has a second diameter 232 and includes a second groove 234 around its side 236 . The first sprocket 222 is spaced apart from the second sprocket 230 within the belt guard 182 such that the belt 238 is taut about opposing portions of the first and second sprockets 222 and 224 and rests within the respective grooves 226 and 234 . Output from the motor 212 interfaces with the first sprocket 222 of the belt drive 220 through corresponding holes in the motor housing 178 and the belt guard 182 . Rotation by the first sprocket 222 is transferred to the second sprocket 230 by the belt 238 . The first diameter 224 is less than the second diameter 232 resulting in more than one rotation of the first sprocket 222 being required to rotate the second sprocket 230 one full rotation. Factors used to determine the desired ratio between the first diameter 224 rotation and the second diameter 232 include the top motor speed, the speed at which it is desired that the choke plate 116 go from a full open position to a full closed position, the precision with which it is desired that the choke plate aperture 118 be positioned relative to the fixed aperture 122 , and the variability of the control of the speed of the motor 212 .
[0036] In one embodiment, an actuator fork 114 interfaces with the second sprocket 230 . In this embodiment, the actuator fork 114 extends through a second hole in the belt guard 182 and is coupled to the choke plate 116 .
[0037] In one embodiment, the hand wheel 240 provides manual control of the actuator fork 114 to rotate the choke plate 116 in the event of power loss or system failure. The hand wheel 240 is connected to a gear reducer (not shown) to increase the number of revolutions required to open and close the choke assembly 106 . After the local panel 150 has been disabled, the manual hand wheel 240 can be used to fully open and close the choke plate 116 in a predetermined number of revolutions. The position of the choke plate 116 can be determined by observing the position indicator 188 .
[0038] The position indicator 188 is housed by the adapter 174 , which is coupled to the actuator end 112 of the choke assembly 106 . In one embodiment, shown in FIG. 10 , the position indicator 188 includes a proximity switch 190 and an indicator ring 198 . In this embodiment, the indicator ring 198 is cylindrical about a center axis 200 and has an indicator side 202 . The indicator ring 198 is rotationally retained within the adapter 174 through its center axis 200 . The indicator ring 198 is coupled to the choke plate 116 . Thus, rotation of the indicator ring 198 corresponds to rotation of the choke plate 116 .
[0039] In one embodiment, a magnet 204 is housed by the indicator ring 198 , flush within the indicator side 202 . In this embodiment, when the magnet 204 engages the proximity switch 190 , a homing response is recognized by the motor 212 . As the operator commands an open/close request to the motor 212 the motor 212 uses preprogrammed algorithms to interpret a homing response and turn the motor 212 a predetermined number of revolutions as required to open/close the choke plate 116 .
[0040] In one embodiment, the proximity switch 190 is coupled to the adapter 174 such that a sensor end 192 is less than a predetermined distance 210 from the indicator side 202 , but far enough from the indicator side 202 that the indicator ring 198 does not contact the sensor end 192 when rotating. The distance 210 between the indicator side 202 and the sensor end 192 is within the range in which the proximity switch 190 can sense the presence of the magnet 204 . Thus, as the indicator ring 198 is rotated, the proximity switch 190 detects the magnet 204 , which corresponds to a predetermined position of the choke plate 116 .
[0041] In one embodiment shown in FIGS. 5-7 , the proximity switch 190 is surrounded by a proximity switch guard 186 affixed to the adapter 174 . The proximity switch guard 186 protects the proximity switch 190 from becoming dislodged or moved from position.
[0042] The proximity switch 190 has a connector end 194 to which a switch communication cable 196 is attached. In one embodiment, the switch communication cable 196 connects to the motor 212 through an open end of the proximity switch guard 186 to provide feed back to the motor 212 of whether the magnet 204 is in front of the sensor end 192 of the proximity switch 190 . When the magnet 204 is detected by the proximity switch 190 a predetermined quantity of times corresponding to a desired choke plate 116 position, the feedback signal stops the motor 212 .
[0043] In one embodiment, the adapter 174 is of a tubular construction wherein an operator can view the indicator ring 198 through an open side of the adapter 174 . In one embodiment, marks on the indicator side 202 can be viewed and the alignment compared with stationary marks on the adapter 174 to determine the position of the choke plate 116 . When an operator uses the handwheel 240 to manually rotate the choke plate 116 , the position indicator 188 is used to indicate the position of the choke plate 116 relative to the fixed plate 120 . In one embodiment, the operator looks through the tubular adaptor 174 , between the choke assembly 106 and the actuator housing 172 and lining up the markings on the indicator ring 198 with the corresponding markings on the top of the adapter 174 .
[0044] One or more sensors 126 are located within the wellbore 102 to measure predetermined parameters. In one embodiment, the remote actuator panel 130 . In one embodiment, sensor communication cables 128 connect the sensors 126 and the local panel 150 . In one embodiment, the remote actuator panel 130 includes preprogrammed algorithms operative to interpret measurement data and transmit responsive instruction to the motor 212 to open or close the choke plate 116 . In one embodiment, wherein the local panel 150 includes the emergency stop button 152 , instruction from the remote actuator panel 130 to the motor 212 is routed through the local panel 150 because the emergency stop cannot be bypassed. In one embodiment, the local panel 152 includes preprogrammed algorithms operative to interpret measurement data and transmit responsive instruction to the motor 212 .
[0045] The apparatus 100 provides the operator with three methods of control. The first method is electronically through the use of the remote panel 130 from a remote location such as the doghouse 103 . The second method allows the operator to control the choke assembly 106 electronically from the local panel 150 in the manifold shack 104 . The final method of control is by using the manual hand wheel 240 coupled to the back of the actuator 170 .
[0046] All of the electronic components are housed in air tight housings 132 , 158 within which continual air purge is provided. The motor housing 178 is explosion proof and an explosion proof junction box 214 receives armored switch and control communication cables 196 and 166 directed to the motor 212 . Thus, the control system 100 is safe for use in a hazardous area pursuant to Class 1 Division 1 standards.
[0047] Referring to FIG. 11 , in one embodiment, there is provided an apparatus for pressure control of a fluid system having at least one redundant, or back-up pressure control device, or choke assembly 106 , 106 ′. This system, generally designated 300 , includes a remote panel 330 , a plurality of local panels 350 , 350 ′, a plurality of actuators 370 , 370 ′, and at least one sensor 326 .
[0048] The choke assemblies 106 , 106 ′ each have a configuration such as that previously described. The single fluid path to the set of chokes 106 , 106 ′ divides to provide an individual fluid path to each choke assembly 106 , 106 ′. A valve may be present to direct flow into one of the individual fluid paths.
[0049] In this embodiment, the remote panel 330 includes a choke selection switch 310 on the panel. In one embodiment, the switch 310 is toggled between two or more detent locations corresponding to the two or more choke assemblies 106 , 106 ′. In one embodiment, the digital display 338 provides data from a selected choke assembly 106 or 106 ′. In another embodiment, the digital display provides data from both choke assemblies 106 , 106 ′ simultaneously. A panel communication cable 342 splits into corresponding segments 342 ′, 342 ″, etc. to provide electronic communication between the remote panel 330 and each local panel 350 , 350 ′. In one embodiment, a molded junction box 345 is present at the intersection of the communication cables.
[0050] To ensure that the remote panel 330 is safe for operation in an area that is classified as hazardous, the housing 332 is air-tight and the air purge system 344 provides clean air into the housing 332 . The air purge system 344 also provides air circulation through each local panel 350 , 350 ′, etc.
[0051] The local panels 350 , 350 ′, located at the choke manifold 104 , provide the secondary interface for the operator to control the chokes 106 , 106 ′. In one embodiment, controls 356 and displays 354 are present. In one embodiment, an emergency stop button 352 , 352 ′ is located on each local panel 350 , 350 ′. Each communication cable segment 342 ′, 342 ″ is connected to the corresponding local panel 350 , 350 ′.
[0052] An actuator 370 , 370 ′ is attached to the actuator end 112 , 112 ′ of a corresponding choke assembly 106 , 106 ′. In one embodiment, each actuator 370 , 370 ′ includes a manual hand wheel 440 , 440 ′, providing manual control of each choke assembly 106 , 106 ′. The local panels 350 , 350 ′ provide electronic control of the corresponding choke assembly 106 , 106 ′. The remote panel 330 , provides remote electronic control of each choke assembly 106 , 106 ′ independently by selecting the appropriate choke 106 , 106 ′ with the choke selection switch 310 .
[0053] It will be understood by those of skill in the art that any number of choke assemblies 106 , 106 ′ may be controlled with the control system 300 described. An actuator 370 , 370 ′ is to be operatively attached to the actuator end of each choke 106 , 106 ′ to be controlled. A local panel 350 , 350 ′ electronically communicates with each actuator 370 , 370 ′. Only one remote panel 330 is required, wherein a choke selection switch 310 is used to select control of any one of the choke assemblies 106 , 106 ′.
[0054] In one aspect, the present invention generally relates to a control system for a pressure control device, or choke assembly, which can be used in a hazardous area and meets standards established by the American Petroleum Institute (API). The pressure control device, or choke, may be used in conjunction with a BOP (Blow Out Preventer) to allow safe evacuation of high-pressure gas/fluids from the well bore during a well control situation (kick). This is accomplished by varying the opening size of the choke valve through which the fluid/gas is flowing to increase/decrease flow in order to maintain a stable drill pipe or casing pressure, depending on the situation.
[0055] While the claimed subject matter has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the claimed subject matter as disclosed herein. Accordingly, the scope of the claimed subject matter should be limited only by the attached claims. | An apparatus operable is a hazardous area for controlling a choke assembly includes an air source, an air purge system in fluid communication with the air source, a remote operating panel receiving data from at least one remotely located wellbore sensor, a local operating panel in electronic communication with the remote operating panel, and an actuator coupled to the assembly to control pressure within the wellbore. The remote operating panel includes an airtight housing in fluid communication with the air purge system, wherein air from the air purge system is circulated through the housing, a plurality of operator controls for manually controlling operation of the pressure control assembly, and a display for visually displaying values of data received from the wellbore sensor. The local operating panel includes an airtight panel housing in fluid communication with the air purge system, wherein air from the air purge system is circulated through the panel housing, and a local operator controller having an operator interface for receiving operator instruction input into the local panel, and operable to receive operator instructions from the remote panel and transmit operator instructions. The actuator includes a motor in an explosion-proof housing coupled to the choke plate and operable to adjust the orifice through the choke plate, wherein the motor receives electronic communication of the operator instructions transmitted by the local operator controller, and a position indicator coupled to the choke plate for sensing the orifice opening and providing feedback of the choke plate position to the motor. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates to a gripper, with highly efficient gripping power, for gripping and transporting weft threads through the shed in continuous weft feed looms.
The gripper according to the invention is a "drawing" gripper, namely a gripper designed to grasp the weft thread about half way through the shed, withdrawing it from a companion "carrying" gripper which has carried it thereto, and draw said thread up to the end of the loom opposite to the feeding end.
Generally, such drawing grippers have been made up to the present with a fixed lower member and with a movable upper hook-shaped member, adapted to oscillate in a vertical plane in respect of the fixed member. Grippers of this type insert themselves in the companion carrying-type grippers, from which the upper hook member draws the weft thread holding it, for its transport, between said upper member and the fixed lower member. The movable hook-shaped member is generally pivoted on a horizontal axis, perpendicular to the longitudinal direction of the gripper, and is pressed by spring means against the fixed member.
Although the conventional drawing grippers work in a fairly satisfactory way, they have some drawbacks concerning the safety in gripping the weft thread, at the moment of drawing the same from the carrying gripper, and concerning the gripping efficiency during subsequent transport of said thread. It is hence desirable to produce grippers which may prevent such drawbacks and improve the performance of looms equipped therewith.
SUMMARY OF THE INVENTION
The object of the present invention is to supply an improved drawing gripper for gripping and transporting weft threads, wherein the movable member is mounted for oscillation in respect of the fixed member about a vertical axis, in a horizontal plane parallel to that containing said fixed member, this latter being provided with a hook end, with the inner part of which cooperates the end of the movable member, under the action of the return spring means.
In a first embodiment of the invention, the cooperation between the fixed member and the movable member takes place in correspondence of the upper surface of the end of the movable member and in correspondence of the inner upper surface of the hook part of the fixed member: the end of the movable member is then usually beveled, to adapt itself to the inner surface, also beveled, of the hook of the fixed member; these two surfaces may have an equal or a different configuration.
In a second and preferred embodiment of the invention, the end of the movable member and the hook part of the fixed member, designed to cooperate one with the other, are formed as conjugated helical surfaces with variable pitch.
The best results are obtained by forming the conjugated helical surfaces in such a way that, when they get close to contact, the mutual distance and the inclination in respect to the horizontal plane of the actual surfaces, decrease towards the end of the gripper.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in further detail with reference to the two cited embodiments thereof, and to some modifications of the same, shown in the accompanying drawings, wherein:
FIG. 1 is a somewhat diagrammatic plan view with parts omitted for simplicity, of the gripper according to the invention in a first embodiment thereof;
FIG. 2 shows in similarly simplified form a modification of the gripper embodiment of FIG. 1;
FIG. 3 is a section view on the line III--III of FIG. 1, illustrating a detail of the return spring means of the gripper;
FIGS. 4 to 7 are cross sections through the hook of the gripper of FIGS. 1 or 2, taken on the line 4--4 of FIG. 2, to show various suitable configurations of the cooperating surfaces of the gripper members;
FIGS. 8 and 9 are enlarged fragmentary top plan views and show the behaviour of the weft thread during operation, according to whether one adopts the embodiment of FIG. 1 or of FIG. 2, of the gripper according to the invention;
FIG. 10 is a longitudinal section through the hook of the gripper according to the invention, taken on the line 10--10 of FIG. 2;
FIG. 11 is a perspective view of a second embodiment of the gripper according to the invention;
FIG. 12 shows a plan view of a detail of mounting the movable member and the means for adjusting the closing position of the same, in the gripper of FIG. 11;
FIG. 13 is a perspective view of a first modification of the second embodiment of the gripper according to the invention;
FIG. 14 is a plan view, similar to that of FIG. 12, showing a detail of the gripper of FIG. 13, with the movable member in a closed position;
FIG. 15 is a plan view showing a detail, as in FIG. 14, with the movable member in an open position;
FIG. 16 is a perspective view of a second modification of the second embodiment of the gripper according to the invention;
FIG. 17 is a plan view, similar to those of FIGS. 12, 14 and 15, showing a detail of the gripper of FIG. 16; and
FIGS. 18, 19 and 20 are other detailed views, designed to show more clearly the characteristics and the operation of the gripper of FIG. 16.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIG. 1, it may be seen that the gripper according to the invention comprises a first lower fixed member 1 and a second movable member 2, being pivoted on the first about the vertical axis 3. The gripper member 1 will be supported by a base, preferably of plastic material, not shown, the characteristics of which may be those of similar components in conventional grippers. Said member 1 terminates at the end of the gripper in a hook 4, arranged in a vertical plane and clearly shown in FIG. 10. Said member 1 is further provided with two lateral supports integral therewith, of which, an intermediate support 5 carries the pivot 3 for oscillating the movable member 2, and a rear support 6 houses the return spring means for the movable member 2.
The movable 2 is formed as an elongated bar, being beveled at the front end 2', widened at the centre with an ear 7 for pivoting on the pivot 3, and thickened at the rear end into a cam projection 8.
The pivoting between the ear 7 and the pivot 3 may be obtained by means of a bearing (preferably a small needle bearing) or by using a pair of aligned and opposed pointed screws, between the points of which is rotatably arranged the ear 7.
The cam projection 8 is designed to cooperate with a tappet of the loom, for releasing the weft thread, as explained hereinafter.
A pin or threadguide 9 may be provided, secured vertically on one side of the hook 4.
Between the lateral support 6 of the fixed member 1 and the side of the movable member 2 facing said support, are arranged return spring means, comprising -- in the case of FIGS. 1 and 3 -- a helical cylindrical spring 6', designed to press the front end of the movable member 2 into contact with the inner upper surface of the hook 4 of the fixed member.
In the modification shown in FIG. 2 (drawn also without the threadguide 9) the lateral support 6 is missing, in that the return spring means interposed between the two members of the gripper, consists of a flat spring 10, fixed to the side of the member 1 and acting also laterally on the member 2, as clearly shown in FIG. 2.
As will have been understood from the already given description, in using the gripper according to the invention, the weft thread carried by the carrying gripper will be grasped by the hook 4 and held between the inner upper surface of said hook and the corresponding upper surface of the end of the movable member 2. For thread engagement, the shape of the two surfaces gripping the thread is of some importance. Said shape varies according to the type of thread to be transported and to the kind of work to be performed. The accompanying drawing shows various interesting combinations of such surfaces shapes.
The inner upper surface 11 of the hook 4 has always been shown as a flat inclined surface, while the corresponding upper surface of the end of the movable member 2 is: in the case of FIG. 4, a flat surface 12 being inclined exactly like the surface 11; in the case of FIG. 5, a flat surface 13 being more inclined than the surface 11 and with a rounded outlet edge; in the case of FIG. 6, a flat horizontal surface 14 with a rounded inlet edge; and in the case of FIG. 7, a substantially cylindrical surface 15.
It is understood that other shapes of the surface 11 and of the corresponding surface of the end of the member 2, may be provided and combined.
In use, the gripper according to the invention is pushed, with its own front part comprising the hook 4, into the carrying gripper, and is then caused to move backward, after that the weft thread stretched through the carrying gripper has gone over the hook 4, said thread being arranged transversely to said hook. At this point, as can be seen from FIGS. 8 or 9, the weft thread penetrates between the hook 4 and the end of the oscillating member 2 cooperating with said hook. The insertion of the thread takes place extremely smoothly and easily, since initially, the traction acting on the thread is that produced by the resistance of the means locking the thread in the carrying gripper: said traction acts according to the arrow R and tends to open the gripper, that is, to cause the member 2 to oscillate towards the left, in FIGS. 8 or 9. At once after the thread has abandoned with its end in the carrying gripper, the traction acting thereon is that produced by the resistance to the advancement of the thread by the feeding reels or similar devices: said traction acts according to the arrow T and tends to close the gripper, that is, to cause the lower member of the gripper to oscillate towards the right, in FIGS. 8 or 9. It thus happens that the insertion of the thread is very safely performed, avoiding the risk -- which is always present in the known grippers -- that the thread itself may be rejected by the hook, and on the other hand, the gripping of the thread between the claws during transport takes place just as safely, said claws acting at this stage as self-locking, hence preventing the risk of a thread loss in the shed. The self-locking effect may be increased by using the threadguide consisting of the pin 9: in fact, by comparing FIGS. 8 and 9, it may easily be seen that the force F, which tends to produce the closing of the gripper, acts -- in the case of FIG. 8 -- almost transversely to the gripper and has, therefore, the highest self-locking effect, while -- in the case of FIG. 9 -- (the pin 9 being absent) only a component of said force will be acting to favour the closing of the gripper. The self-locking effect obtained thereby, allows one to considerably reduce -- compared to the known devices -- the intensity of the force produced by the springs 6' or 10.
It is understood that the gripper is normally pressed towards the closing position by the spring means 6' or 10, which are released only upon freeing of the weft thread, once the gripper has come out of the shed, at the end opposite to the feeding end. For this purpose -- as has been said -- a tappet, for example in the form of a block fixed to the loom, acts on the cam projection 8, to cause the rotation of the oscillating claw 2, so as to carry the end thereof outwardly and out of engagement from the hook 4. It is understood that said tappet or block may be adjustable, to suit the opening of the gripper to the type of yarn being used.
Considering now the second embodiment, shown in the drawings, of the drawing gripper according to the invention, let us examine first of all the FIGS. 11 and 12: therein, the drawing gripper consists of a basic body 21, the rear part of which may be connected to a strap or rod for controlling the gripper itself (not shown), and the front part of which carries the fixed member 22 and the movable member 23. The basic body 21, designed to travel through the loom shed in a horizontal position, comprises a lateral wing 24, which is appropriately shaped for protection purposes and which is designed to take up a vertical position.
The fixed member 22 is obtained in one piece with, or is fixed by any known means to the basic body 21 and it may be made of the same material thereof, or of a different material. Preferably, the basic body 21 will be made of highly resisting synthetic plastic material, while the fixed member 22 will be of metal. As can be seen, the end of the member 22 terminates with a hook 25, the surface 26 of which is a variable pitch helical surface.
The movable member 23 consists of a metal toggle lever pivoted about axis 27 to the basic body 21, by means of a pivot 28. The movable member 23 has its end 23', close to the hook 25 of the fixed member 22, formed with a variable pitch helical surface 29, conjugated to the surface 26 of the fixed member: the surfaces 26 and 29 of the two members 22 and 23 are designed to cooperate in the manner specified hereinafter, in order to carry out the gripping of the weft thread to be transported.
The movable member 23 is pushed with its end 29 towards the hook 25 of the fixed member 22, by the action of a flat spring 30, acting at the other end thereof: said spring 30 is carried by the basic body 21 of the gripper, with possibility of adjustment by means of the screw 31. A plate 32 is parallel to the basic body 21 and fixed thereto by means of screws 33.
The plate 32 may be entirely made of damping material or it may be provided with a damping block in correspondence of its extension 32', contacting the movable member 23, said extension being separated from the remaining part of the plate by a longitudinal slit 32". The plate 32 also carries a micrometer adjustment screw 34, whose point engages the extension 32', in order to resiliently vary the position thereof. Since, with the gripper in a closed position, the extension 32' of the plate opposes the inner surface of the movable member 23, the above allows one to vary the relative position between the two members 22 and 23, with closed gripper, and hence to appropriately adjust the width of the opening between the two conjugated gripping surfaces 26 and 29, at the ends of the two members.
The particular damping nature of the material forming the plate 32 allows one to absorb any vibrations which may be produced on the movable member, and considerably reduces the impact effect occurring between the movable member 23 and the extension 32' of the plate, when the gripper, after opening for releasing the weft thread, goes back to the original closed position by the action of the spring 30.
The reference 35 indicates a fixed gripper-opener, designed to act on the rear curved part 23" of the member 23, in order to open the same at its passage before said opener.
By this arrangement, in using the grippers, the movable member 23 places itself close to the fixed claw 22, so as to create a slit between the surfaces 26 and 29 (which are normally not in contact, due to the action of the plate extension 32' produced by the screw 34), the width and inclination of said slit, in respect of the horizontal direction, decreasing towards the ends of the members themselves.
In operation, the weft thread is grasped by the hook 25 from the inside of the carrying gripper, inserting itself in the aforementioned slit, between the member 22 and the member 23, where it automatically finds its gripping position, in correspondence of the point where the gripping force determined by the coupling between the members 22 and 23 balances the tension of the thread produced by the feed braking. It so happens that the thicker or less braked yarns are inserted at the start of the slit, while the thinner or more braked yarns take place at the end of the slit. In other words, the end part 29 of the movable member 23 acts as a wedge, which is restrained under the helical surface 26 of the fixed member 22, placed under the hook 25. Once the weft thread has been gripped, the two surfaces can by no means come into contact, since the weft thread is inserted between them. As has been said, the inclination of said wedge, considered in a direction transverse to the movement direction of the grippers, and in respect of the horizontal plane, slowly decreases towards the end of the two members.
The coupling force between the surfaces 26 and 29 is constant and is produced by the tension of the spring 30.
If the weft thread is inserted at the start of the slit between said surfaces, where the inclination of the actual surfaces is more pronounced, the gripping pressure on the thread is relatively modest, since the above wedge has a strong opening angle. In this position will hence be inserted, as already said, the thick or scarcely braked wefts. Whereas, if the weft thread tension is higher, it tends to open the gripper and the thread slides into the slit, between the surfaces 26 and 29, up to reaching an area where the opening angle of the wedge is smaller, whereby, with an equal action by the contrast spring, a higher gripping force may be exerted. It is hence understood that the end of the thread will automatically find its gripping position where the gripping pressure balances the thread tension. Therefore, with a constant load contrast spring one is able to obtain an increasing gripping force, as the distance from the end of the members decreases, taking advantage of the fact that the inclination of the surfaces 26 and 29, between which gripping takes place, varies.
The gripping capacity hence becomes, within wide limits, independent from the braking and from the count of the weft thread. The gripper is thus very versatile and it allows an excellent operation in weaving conditions with alternate insertion of two or more wefts having different counts or brakings.
Since, as has been seen, the gripping force depends on the inclination of the contact surfaces close to the point where the grasped thread has automatically reached its balance position, and is independent from the tension of the spring 10, the operator should not, as a rule, interfere to adjust the tension of the spring, according to the braking and to the count of the weft thread.
Moreover, the friction which is created between the end of the thread and the two gripping surfaces, has a damping effect against any vibrations of the spring and eliminates the danger of failed gripping, through separation of the said surfaces caused by vibrations which, especially at high speeds, are likely to be produced on the spring pressing the movable member against the fixed member.
On the other hand, the presence of the screw 34 for adjusting the closing position of the movable member 23 onto the fixed member 22, allows the opening of the slit between the members to be adjusted according to a range of high count yarns or to a range of low count yarns, while the two gripping surfaces 26 and 29 are prevented from coming into contact and from getting caught one into the other when, in the forward stroke, the thread is not gripped.
The same arrangement dampens the vibrations of the two members and of the spring 30 acting onto the movable member.
In the modification of the gripper embodiment shown in FIGS. 13 to 15, the movable member 23 is still pivoted at 27, with its rear part terminating however -- instead of in a tail being directly subjected to the action of the spring 10, as in the gripper of FIG. 1 -- in an extension 36, to which is connected, at 37, an articulated curved lever 38, urged by the spring 30 and pivoted, at 39, to a straight lever 40, pivoted at 41. The action of the spring 30 is thus transmitted to the member 23, through an articulated quadrilateral 27, 37, 39, 41, which also determines the opening movement of the member 23, when the curved lever 38 runs into the gripper-opener 35. This solution ensures a perfect gripping of the weft thread throughout insertion, in that, when the levers 38 and 40 come into alignment, the movable member 23 is forced to adhere to the fixed member 22 (FIG. 14).
In this way, the vibrations and possible impacts, to which the gripper may be subjected during insertion, do not produce relative displacements between the movable member 23 and the fixed member 22. For this purpose, the arrangement of FIGS. 13 and 14 comprises a pin 42, which is fixed to the gripper body by means of an eccentric pivot, allowing one to adjust its distance in respect of the quadrilateral 27, 37, 39, 41, and a square extension 43 of the lever 40, adapted to bear on the pin 42 when the gripper is in a closed position. A unilateral bond (adjustable in position) is thus created for the quadrilateral, so as to obtain the aforespecified alignment of the levers.
At the end of the insertion, when the gripper gets close to one end of the fabric, the gripper-opener 35 acts on the curved lever 38 and changes the configuration of the quadrilateral 27, 37, 39, 41, from the shape of FIG. 14, to that of FIG. 15. The levers 38 and 40 get hence shifted from the aligned position (FIG. 14) to the position forming an angle, and the extension 36 of the claw 23 is caused to rotate, thus allowing the opening of the gripper (FIG. 15).
The above described embodiment, in addition to ensuring a perfect and constant gripping during the insertions -- which is particularly significant in the case of very thin weft yarns -- also provides the considerable advantage of requiring a spring 30, acting with a spring load which is far lower than that of the spring provided for the previously described embodiment. This also provides the advantage of being able to use, in the gripper-opener 35, lower freeing pressures on the lever 38, with consequent minor friction and wear. The result is also a smaller percentage of weft losses at the outlet of the shed, with the loom working at high speeds.
In the embodiment of FIGS. 16 to 20, one obtains the control of the movable member 23, during insertion, by means of an appropriately shaped sector 44, oscillating about a pivot 44' emerging from the gripper body, which sector inserts itself into an opening 45 of the curved tail 46 of the movable member 23.
The sector 44 is pressed against the movable member 23 by a spiral spring 47, having one end tied to the pivot 44' and the opposite end fixed to said sector. The spring 47 is pre-loaded so as to create a torque acting on the sector 44.
The sector 44, free to rotate about the pivot 44', has a cam surface eccentric to said pivot, so that, when the sector is caused to rotate, the distance between said sector and the end 48 of the opening 45 may vary.
In a closed position of the gripper, said distance is automatically annulled by the action of the spiral spring 47, and the contact between the point 48 of the curved tail 46 of the claw 23 and the sector 44, determines the working position of the movable claw, as shown in FIG. 18. In such conditions, one obviously has the same advantages of regularity and weft gripping safety, which have already been pointed out in connection with the solution of FIGS. 13 to 15.
The opening of the gripper by the gripper-opener 35 takes place in two stages: in the first stage, the gripper-opener 35 acts on the sector 44 and causes its rotation, as shown in FIG. 19: in this way, the engagement between the sector 44 and the movable member 23 is eliminated; in the second stage, the gripper arranges itself so that the gripper-opener 35 may act simultaneously on the sector 44 and on the part of the movable member corresponding to the intermediate area of the opening 45, hence causing the opening of the gripper and the freeing of the thread. Once the action of the gripper-opener has come to an end, the gripper closes due to the combined effect of the elastic return of the movable member, subject to the action of the flat spring 30, and of the elastic return of the sector 44, subject to the action of the spiral spring 47. | A drawing gripper for gripping and transporting weft yarns in continuous weft feed looms, which draws the weft thread from the carrying gripper at the center of the shed and transports the same out of the shed, said drawing gripper comprising a fixed member carried by a support connected to the means for moving forward the gripper itself, and a movable member, oscillating in respect of the fixed member about a vertical axis, in a horizontal plane parallel to that containing said fixed member. This latter is provided with a hook end extending in a vertical plane, with the inner upper part of which cooperates the end of the movable member, under the action of return spring means. | 3 |
APPLICATION DATA
[0001] This application is a divisional of U.S. application Ser. No. 09/735,160 filed Dec. 12, 2000.
FIELD OF INVENTION
[0002] The present invention relates to synthesis of heteroarylamine intermediate compounds.
BACKGROUND OF THE INVENTION
[0003] Aryl- and heteroaryl-substituted ureas have been described as inhibitors of cytokine production. These inhibitors are described as effective therapeutics in cytokine-mediated diseases, including inflammatory and autoimmune diseases. Examples of such compounds are reported in WO 99/23091 and in WO 98/52558.
[0004] A key step in the synthesis of these compounds is the formation of the urea bond. Various methods have been reported to accomplish this. For example, as reported in the above references, an aromatic or heteroaromatic amine, II, may be reacted with an aromatic or heteroaromatic isocyanate III to generate the urea IV (Scheme I)
[0005] If not commercially available, one may prepare the isocyanate III by reaction of an aryl or heteroaryl amine Ar 2 NH 2 with phosgene or a phosgene equivalent, such as bis(trichloromethyl) carbonate (triphosgene) (P. Majer and R. S. Randad, J. Org. Chem. 1994, 59, 1937) or trichloromethyl chloroformate (diphosgene) (K. Kurita, T. Matsumura and Y. Iwakura, J. Org. Chem. 1976, 41, 2070) to form the isocyanate III, followed by reaction with Ar 1 NH 2 to provide the urea. Other approaches to forming the urea reported in the chemical literature include reaction of a carbamate with an aryl or heteroaryl amine, (see for example B. Thavonekham, Synthesis, 1997, 1189 and T. Patonay et al., Synthetic Communications, 1996, 26, 4253) as shown in Scheme II below for a phenyl carbamate. U.S. patent application Ser. No. 09/611,109 also discloses a process of making heteroaryl ureas by reacting particular carbamate intermediates with the desired arylamine.
[0006] U.S. application Ser. No. 09/505,582 and PCT/US00/03865 describe cytokine inhibiting ureas of formula (I).
[0007] An Ar 2 NH 2 required to prepare preferred compounds described therein is illustrated as formula (A).
[0008] wherein W, Y, and Z are described below.
[0009] The synthesis of II, a preferred formula (A) intermediate was described in U.S. application Ser. No. 09/505,582 and PCT/US00/03865 and is illustrated in Scheme III.
[0010] The synthesis begins with a palladium catalyzed carbonylation of 2,5-dibromopyridine (III) to provide ester IV in 55% yield. The reaction is run under pressure (80 psi CO) and must be monitored to minimize formation of the diester, an unwanted by-product. Reduction of IV with diisobutylaluminum hydride at −78° C. provides aldehyde V. This is followed by reductive amination to give VI.
[0011] Intermediate VI is then converted to II by reaction with t-BuLi at −78° C. followed by tributyltin chloride to give tributylstannane VII, followed by palladium catalyzed Stille coupling with intermediate VIII to give II. Conversion of VI and analogous intermediates to other intermediates of formula II via Suzuki coupling is also described in U.S. application Ser. No. 09/505,582 and PCT/US00/03865 (Scheme IV). According to this method, intermediate IX is treated with n-BuLi followed by trimethylborate to give arylboronic acid X. Palladium catalyzed Suzuki coupling with VI provides XI, which is deprotected by treatment with acid to give II.
[0012] This process is not well-suited for large-scale and commercial use for several reasons. One reaction (Scheme III) is run under high pressure (80 psi) and another at extreme temperature (−78° C.). The yield of IV is only moderate and by-product formation requires a purification step. These factors, plus the cost of starting materials and reagents make this process too costly for commercial scale.
[0013] The preparation of 2-bromo-5-lithiopyridine via reaction of 2,5-dibromopyridine with n-BuLi at −100° C. has been described (W. E. Parham and R. M. Piccirilli, J. Org. Chem., 1977, 42, 257). The selective formation of 2-bromo-5-pyridinemagnesium chloride via reaction with 2,5-dibromopyridine with i-PrMgCl at 0° C.—rt has also been reported (F. Trecourt et al., Tetrahedron Lett., 1999, 40, 4339). In these cases, the metal-halogen exchange occurred exclusively at the 5 position of the pyridine ring. However, the syntheses of 5-bromo-2-pyridinemagnesium chloride and 5-chloro-2-pyridinemagnesium chloride have not been reported previously.
[0014] The preparation of a lithium intermediate 5-chloro-2-lithiopyridine from 2-bromo-5-chloropyridine, has been reported (U. Lehmann et al., Chem., Euro. J., 1999, 5, 854). However, this synthesis requires reaction with n-BuLi at −78° C. The preparation of the 5-bromo-2-lithiopyridine from 2,5-dibromopyridine was reported by X. Wang et al. ( Tetrahedron Letters, 2000, 4335). However, the method requires cryogenic and high dilution conditions. The selectivity was also dependent on reaction time. It is not suitable for large scale synthesis.
[0015] The synthesis of the intermediate 5-bromo-2-iodopyridine by refluxing 2,5-dibromopyridine in HI has been reported (U. Lehmann, ibid). A process using milder conditions for preparing 2-iodopyridine from 2-chloro or 2-bromopyridine has been described (R. C. Corcoran and S. H. Bang, Tetrahedon Lett., 1990, 31, 6757).
SUMMARY OF THE INVENTION
[0016] It is an object of the invention to provide novel 2-(5-halopyridyl) and 2-(5-halopyrimidinyl) magnesium halides, novel methods of producing them, and to provide a novel method of using said halides in the efficient synthesis of their respective 5-halo-2-substituted pyridines and pyrimidines.
[0017] It also an object of the invention to provide a novel method of producing heteroaryl amines of the formula (A)
[0018] wherein Ar, W, Y and Z are described below, the heteroaryl amines are useful in the production of heteroaryl ureas as mentioned above.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] This invention relates to a novel strategy for the synthesis of heteroarylamine compounds of the formula (A) which constitute the key component of pharmaceutically active compounds possessing a heteroaryl urea group.
[0020] The invention therefore provides for processes of making a compound of the formula (A)
[0021] wherein:
[0022] W is CR 3 or N, wherein R 3 is chosen from hydrogen, C 1-5 alkyl, C 1-5 alkoxy, arylC 0-5 alkyl and —COR 4 wherein R 4 is chosen from C 1-5 alkyl, C 1-5 alkoxy, arylC 0-5 alkyl and amino which is optionally independently di-substituted by C 1-5 alkyl, and arylC 0-5 alkyl; W is preferably CH or N,
[0023] Ar is chosen from
[0024] phenyl, naphthyl, quinolinyl, isoquinolinyl, tetrahydronaphthyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl, benzimidazolyl, benzofuranyl, dihydrobenzofuranyl, indolinyl, benzothienyl, dihydrobenzothienyl, indanyl, indenyl and indolyl each being optionally substituted by one or more R 1 or R 2 ;
[0025] Y is chosen from
[0026] a bond and a C 1-4 saturated or unsaturated branched or unbranched carbon chain optionally partially or fully halogenated, wherein one or more methylene groups are optionally replaced by O, N, or S(O) m and wherein Y is optionally independently substituted with one to two oxo groups, phenyl or one or more C 1-4 alkyl optionally substituted by one or more halogen atoms;
[0027] wherein when Y is the carbon chain, the left side terminal atom of Y is a carbon (the atom which is covalently attached to the heterocycle possessing W):
[0028] Z is chosen from:
[0029] aryl, heteroaryl chosen from pyridinyl, piperazinyl, pyrimidinyl, pyridazinyl, pyrazinyl, imidazolyl, pyrazolyl, triazolyl, furanyl, thienyl and pyranyl and heterocycle chosen from tetrahydropyrimidonyl, cyclohexanonyl, cyclohexanolyl, 2-oxo- or 2-thio-5-aza-bicyclo[2.2.1]heptanyl, pentamethylene sulfidyl, pentamethylene sulfoxidyl, pentamethylene sulfonyl, tetramethylene sulfidyl, tetramethylene sulfoxidyl or tetramethylene sulfonyl, tetrahydropyranyl, tetrahydrofuranyl, 1,3-dioxolanonyl, 1,3-dioxanonyl, 1,4-dioxanyl, morpholinyl, thiomorpholinyl, thiomorpholinyl sulfoxidyl, thiomorpholinyl sulfonyl, piperidinyl, piperidinonyl, pyrrolidinyl and dioxolanyl, each of the aforementioned Z are optionally substituted with one to three halogen, C 1-6 alkyl, C 1-6 alkoxy, C 1-3 alkoxy-C 1-3 alkyl, C 1-6 alkoxycarbonyl, aroyl, C 1-3 acyl, oxo, pyridinyl-C 1-3 alkyl, imidazolyl-C 1-3 alkyl, tetrahydrofuranyl-C 1-3 alkyl, nitrile-C 1-3 alkyl, nitrile, phenyl wherein the phenyl ring is optionally substituted with one to two halogen, C 1-6 alkoxy or mono- or di-(C 1-3 alkyl)amino, C 1-6 alkyl-S(O) m , or phenyl-S(O) m wherein the phenyl ring is optionally substituted with one to two halogen, C 1-6 alkoxy, halogen or mono- or di-(C 1-3 alkyl)amino;
[0030] or Z is optionally substituted with one to three amino or amino-C 1-3 alkyl wherein the N atom is optionally independently mono- or di-substituted by aminoC 1-6 alkyl, C 1-3 alkyl, arylC 0-3 alkyl, C 1-5 alkoxyC 1-3 alkyl, C 1-5 alkoxy, aroyl, C 1-3 acyl, C 1-3 alkyl-S(O) m — or arylC 0-3 alkyl-S(O) m — each of the aforementioned alkyl and aryl attached to the amino group is optionally substituted with one to two halogen, C 1-6 alkyl or C 1-6 alkoxy;
[0031] or Z is optionally substituted with one to three aryl, heterocycle or heteroaryl as hereinabove described in this paragraph each in turn is optionally substituted by halogen, C 1-6 alkyl or C 1-6 alkoxy;
[0032] or Z is nitrile, amino wherein the N atom is optionally independently mono- or di-substituted by C 1-6 alkyl or C 1-3 alkoxyC 1-3 alkyl, C 1-6 alkyl branched or unbranched, C 1-6 alkoxy, nitrileC 1-4 alkyl, C 1-6 alkyl-S(O) m , aryl chosen from phenyl, pyridinyl, pyrimidinyl, pyridazinyl, pyrazinyl, imidazolyl, pyrazolyl, triazolyl, tetrazolyl, faranyl, thienyl and pyranyl each aryl being optionally substituted with one to three halogen, C 1-6 alkyl, C 1-6 alkoxy, di-(C 1-3 alkyl)amino, C 1-6 alkyl-S(O) m or nitrile, and phenyl-S(O) m , wherein the phenyl ring is optionally substituted with one to two halogen, C 1-6 alkoxy or mono- or di-(C 1-3 alkyl)amino;
[0033] R 1 and R 2 are independently chosen from:
[0034] a C 1-6 branched or unbranched alkyl optionally partially or fully halogenated, acetyl, aroyl, C 1-4 branched or unbranched alkoxy, each being optionally partially or fully halogenated, halogen, methoxycarbonyl, C 1-3 alkyl-S(O) m optionally partially or fully halogenated, or phenylsulfonyl;
[0035] m=0, 1 or 2;
[0036] All terms as used herein in this specification, unless otherwise stated, shall be understood in their ordinary meaning as known in the art. For example, “C 1-6 alkoxy” is a C 1-6 alkyl with a terminal oxygen, such as methoxy, ethoxy, propoxy, pentoxy and hexoxy. All alkyl, alkenyl and alkynyl groups shall be understood as being branched or unbranched where structurally possible and unless otherwise specified. Other more specific definitions are as follows:
[0037] Ac—acetyl;
[0038] DBA—dibenzylideneacetone;
[0039] DPPF—1,1′-bis(diphenylphosphino)ferrocene;
[0040] DPPE—1,2-bis(diphenylphosphino)ethane;
[0041] DPPB—1,4-bis(diphenylphosphino)butane;
[0042] DPPP—1,3-bis(diphenylphosphino)propane;
[0043] BINAP—2,2′-bis(diphenylphosphino)-1,1′-binaphthyl;
[0044] DME—ethylene glycol dimethylether;
[0045] DMSO—dimethyl sulfoxide;
[0046] DMF—N,N-dimethylformamide;
[0047] EtO—ethoxide;
[0048] [0048] i Pr—isopropyl;
[0049] [0049] t Bu—tertbutyl;
[0050] THF—tetrahydrofuran;
[0051] RT or rt—room temperature;
[0052] The term “aroyl” as used in the present specification shall be understood to mean “benzoyl” or “naphthoyl”.
[0053] The term “aryl” as used herein shall be understood to mean aromatic carbocycle, preferably phenyl and naphthyl, or heteroaryl.
[0054] The term “heterocycle”, unless otherwise noted, refers to a stable nonaromatic 4-8 membered (but preferably, 5 or 6 membered) monocyclic or nonaromatic 8-11 membered bicyclic heterocycle radical which may be either saturated or unsaturated. Each heterocycle consists of carbon atoms and one or more, preferably from 1 to 4 heteroatoms selected from nitrogen, oxygen and sulfur. The heterocycle may be attached by any atom of the cycle, which results in the creation of a stable structure. Unless otherwise stated, heterocycles include but are not limited to, for example oxetanyl, pyrrolidinyl, tetrahydrofuranyl, tetrahydrothiophenyl, piperidinyl, piperazinyl, morpholinyl, tetrahydropyranyl, dioxanyl, tetramethylene sulfonyl, tetramethylene sulfoxidyl, oxazolinyl, thiazolinyl, imidazolinyl, tertrahydropyridinyl, homopiperidinyl, pyrrolinyl, tetrahydropyrimidinyl, decahydroquinolinyl, decahydroisoquinolinyl, thiomorpholinyl, thiazolidinyl, dihydrooxazinyl, dihydropyranyl, oxocanyl, heptacanyl, thioxanyl, dithianyl or 2-oxa- or 2-thia-5-aza-bicyclo[2.2.1]heptanyl.
[0055] The term “heteroaryl”, unless otherwise noted, shall be understood to mean an aromatic 5-8 membered monocyclic or 8-11 membered bicyclic ring containing 1-4 heteroatoms such as N, O and S. Unless otherwise stated, such heteroaryls include: pyridinyl, pyridonyl, quinolinyl, dihydroquinolinyl, tetrahydroquinoyl, isoquinolinyl, tetrahydroisoquinoyl, pyridazinyl, pyrimidinyl, pyrazinyl, benzimidazolyl, benzthiazolyl, benzoxazolyl, benzofuranyl, benzothiophenyl, benzpyrazolyl, dihydrobenzofuranyl, dihydrobenzothiophenyl, benzooxazolonyl, benzo[1,4]oxazin-3-onyl, benzodioxolyl, benzo[1,3]dioxol-2-onyl, tetrahydrobenzopyranyl, indolyl, indolinyl, indolonyl, indolinonyl, phthalimidyl.
[0056] Terms which are analogs of the above cyclic moieties such as aryloxy or heteroaryl amine shall be understood to mean an aryl, heteroaryl, heterocycle as defined above attached to it's respective functional group.
[0057] As used herein, “nitrogen” and “sulfur” include any oxidized form of nitrogen and sulfur and the quaternized form of any basic nitrogen.
[0058] The term “halogen” as used in the present specification shall be understood to mean bromine, chlorine, fluorine or iodine except as otherwise noted. The compounds made by the novel processes of the invention are only those which are contemplated to be ‘chemically stable’ as will be appreciated by those skilled in the art. For example, a compound which would have a ‘dangling valency’, or a ‘carbanion’ are not compounds made by processes contemplated by the invention.
[0059] In one embodiment of the invention there is provided a process of making the compounds of formula (A) as described hereinabove,
[0060] said process comprising:
[0061] a) synthesis of a compound of formula (C) from a compound of formula (B) via substitution with an appropriate halide X c . When X c is Br, methods known in the art may be utilized.
[0062] When X c is I, the present invention provides a novel process for the substitution of the leaving group (L) with iodide. This was achieved by using the conditions of R x COCl or (R x CO) 2 O/metal iodide/solvent/heating (25° C.-150° C.), wherein Rx is chosen from —C 1-7 alkyl, —CF 1-3 and —CCl 1-3 ; the metal chosen from Na and K, and the solvent chosen from acetonitrile, acetone, DMSO, DMF and THF. Preferred conditions are AcCl and NaI in acetonitrile at 70-90° C. The leaving group L is any suitable leaving group as will be appreciated by those skilled in the art, preferably L is chosen from Cl, Br, —OCOR y and —OS(O) m R y , wherein R y is aryl optionally substituted by C 1-4 alkyl optionally halogenated, such as tolyl, or R y is C 1-4 alkyl optionally halogenated such as CF 3 and CCl 3 , L is more preferably chosen from Br and Cl.
[0063] X a is chosen from Br and Cl, preferably Br;
[0064] X c is I or Br, preferably I;
[0065] X a is attached via the 4 or 5 ring position, preferably the 5 position.
[0066] b) In a one pot process, reacting a compound of the formula (C) with a Grignard reagent R—Mg—X b followed by the addition of an E-Y-Z compound wherein Y-Z is as defined above, said E-Y-Z component is further characterized as being an electrophilic derivative of Y-Z and being appropriate for Grignard reagant reactions as will be apparent to the skilled artisan, said reaction taking place in a suitable aprotic solvent at −78° C. to RT, preferably 0° C. to RT for a reaction time of ½ hour to 2 hours, preferably 1 hour, and isolating the compound of the formula (D);
[0067] wherein:
[0068] X b is chosen from Br, Cl and I;
[0069] R is aryl, C 1-6 alkyl or C 5-7 cycloalkyl;
[0070] As seen in Scheme V below, this one pot novel process step provides for the formation of the Grignard reagant Compound (F):
[0071] where a desirable selective formation was observed. For example the synthesis of 2-(5-halopyridyl)magnesium halides (e.g. 3 and 12) was achieved for the first time.
[0072] The process of making compounds of the formula (F) comprises:
[0073] reacting a compound of the formula (C)
[0074] with a magnesium reagent of the formula R—MgX b ; said reaction taking place in a suitable aprotic solvent at −78° C. to RT, for a reaction time of ½ hour to 2 hours, producing the Grignard compound of the formula (F);
[0075] and wherein
[0076] X a , is halogen selected from Br and Cl, and X a is attached via the 4 or 5 ring position;
[0077] X b is halogen chosen from Br, Cl and I;
[0078] X c is I or Br;
[0079] W is CR 3 or N, wherein R 3 is chosen from hydrogen, C 1-5 alkyl, C 1-5 alkoxy, arylC 0-5 alkyl and —COR 4 wherein R 4 is chosen from C 1-5 alkyl, C 1-5 alkoxy, arylC 0-5 alkyl and amino which is optionally independently or di-substituted by C 1-5 alkyl, and arylC 0-5 alkyl; W is preferably CH or N; and
[0080] R is aryl, C 1-6 alkyl or C 5-7 cycloalkyl.
[0081] In a preferred embodiment there is provided a process for making a compound of the formula (F) as described above and wherein
[0082] W is CH;
[0083] X a is Br and attached at the 5 ring position;
[0084] X c is I;
[0085] the temperature is 0° C. to RT; and
[0086] the reaction time is 1 hour.
[0087] Non-limiting examples of this reaction proceeded with complete selectivity at the 2 position in excellent yield:
[0088] In subsequent steps, the novel process of the invention further comprises:
[0089] c) reacting the compound of the formula (D) from step b) with an aryl boronic acid of the formula (E), in the presence of a catalyst chosen from nickel and palladium. Regarding the palladium(Pd) catalyst, non-limiting examples are Pd catalysts chosen from Pd(PPh 3 ) 2 Cl 2 , Pd(PPh 3 ) 4 , PdCl 2 (DPPE), PdCl 2 (DPPB), PdCl 2 (DPPP), PdCl 2 (DPPF) and Pd/C; or the combination of a palladium source and an appropriate ligand, with the Pd source, for example, being chosen from PdCl 2 , Pd(OAc) 2 , Pd 2 (DBA) 3 , Pd(DBA) 2 , and with the ligand being chosen from PPh 3 , DPPF, DPPP, DPPE, DPPB, P(o-tolyl) 3 , P(2,4,6-trimethoxyphenyl) 3 , AsPh 3 , P( t Bu) 3 , BINAP, and those bound to solid supports that are mimics of the aforementioned ligands, preferably PdCl 2 and PPh 3 . Regarding the nickel (Ni) catalyst, examples of nickel (Ni) catalyst are those chosen from Ni(PPh 3 ) 2 Cl 2 , Ni(PPh 3 ) 4 , NiCl 2 (DPPE), NiCl 2 (DPPB), NiCl 2 (DPPP), NiCl 2 (DPPF) and Ni/C; or the combination of a Ni source and an appropriate ligand, with the Ni source being NiCl 2 , and with the ligand being chosen from PPh 3 , DPPF, DPPP, DPPE, DPPB, P(o-tolyl) 3 , P(2,4,6-trimethoxyphenyl) 3 , AsPh 3 , P( t Bu) 3 , BINAP, and those bound to solid supports that are mimics of the aforementioned ligands. This reaction takes place in a suitable solvent such as ethylene glycol dimethyl ether (DME), THF, toluene, methylene chloride or water, preferably DME, at 0° C. to 150° C., preferably 25° C. to 100° C., for a period of 1 to 24 hours preferably about 15 hours,
[0090] wherein P in the formula (E) is an amino protecting group such as Boc, and subsequently removing said protecting group under suitable conditions to produce a compound of the formula (A).
[0091] In a preferred embodiment of the invention there is provided a novel process of making compounds of the formula (A) as described above and wherein:
[0092] W is CH;
[0093] Ar is chosen from naphthyl, quinolinyl, isoquinolinyl, tetrahydronaphthyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl, indanyl, indenyl and indolyl each being optionally substituted by one or more R 1 or R 2 groups;
[0094] Y is chosen from:
[0095] a bond and
[0096] a C 1-4 saturated or unsaturated carbon chain wherein one of the carbon atoms is optionally replaced by O, N, or S(O) m and wherein Y is optionally independently substituted with one to two oxo groups, phenyl or one or more C 1-4 alkyl optionally substituted by one or more halogen atoms; wherein when Y is the carbon chain, the left side terminal atom of Y is a carbon (the atom which is covalently attached to the heterocycle possessing W):
[0097] Z is chosen from:
[0098] phenyl, pyridinyl, pyrimidinyl, pyridazinyl, pyrazinyl, imidazolyl, furanyl, thienyl, dihydrothiazolyl, dihydrothiazolyl sulfoxidyl, pyranyl, pyrrolidinyl which are optionally substituted with one to three nitrile, C 1-3 alkyl, C 1-3 alkoxy, amino or mono- or di-(C 1-3 alkyl)amino;
[0099] tetrahydropyranyl, tetrahydrofuranyl, 1,3-dioxolanonyl, 1,3-dioxanonyl, 1,4-dioxanyl, morpholinyl, thiomorpholinyl, thiomorpholinyl sulfoxidyl, piperidinyl, piperidinonyl, piperazinyl, tetrahydropyrimidonyl, pentamethylene sulfidyl, pentamethylene sulfoxidyl, pentamethylene sulfonyl, tetramethylene sulfidyl, tetramethylene sulfoxidyl or tetramethylene sulfonyl which are optionally substituted with one to three nitrile, C 1-3 alkyl, C 1-3 alkoxy, amino or mono- or di-(C 1-3 alkyl)amino; nitrile, C 1-6 alkyl-S(O) m , halogen, C 1-4 alkoxy, amino, mono- or di-(C 1-6 alkyl)amino and di-(C 1-3 alkyl)aminocarbonyl;
[0100] In a more preferred embodiment of the invention there is provided a novel process of making compounds of the formula (A) as described immediately above and wherein:
[0101] Ar is naphthyl;
[0102] Y is chosen from:
[0103] a bond and
[0104] a C 1-4 saturated carbon chain wherein the left side terminal atom of Y is a carbon (the atom which is covalently attached to the heterocycle possessing W) and one of the other carbon atoms is optionally replaced by O, N or S and wherein Y is optionally independently substituted with an oxo group;
[0105] Z is chosen from:
[0106] phenyl, pyridinyl, pyrimidinyl, pyridazinyl, pyrazinyl, imidazolyl, dihydrothiazolyl, dihydrothiazolyl sulfoxide, pyranyl and pyrrolidinyl which are optionally substituted with one to two C 1-2 alkyl or C 1-2 alkoxy;
[0107] tetrahydropyranyl, morpholinyl, thiomorpholinyl, thiomorpholinyl sulfoxidyl, piperidinyl, piperidinonyl, piperazinyl and tetrahydropyrimidonyl which are optionally substituted with one to two C 1-2 alkyl or C 1-2 alkoxy; and
[0108] C 1-3 alkoxy;
[0109] In yet a more preferred embodiment of the invention there is provided a novel process of making compounds of the formula (A) as described immediately above and wherein:
[0110] Ar is 1-naphthyl wherein the NH 2 is at the 4 position;
[0111] Y is chosen from:
[0112] a bond, —CH 2 —, —CH 2 CH 2 — and —C(O)—,;
[0113] In an ultimately preferred embodiment of the invention there is provided a novel process of making compounds of the formula (A) as described immediately above and wherein:
[0114] Y is
[0115] —CH 2 —;
[0116] Z is morpholinyl;
[0117] Formation of the reaction intermediate (E) can be accomplished by first protecting an aryl-amine followed by boronic acid formation through a sequence of metal-bromine exchange, quenching with trialkylborate and hydrolysis, as can be seen in Scheme V in the conversion of 7 to 9. Compounds of the formula (E) possessing other desired Ar can be accomplished without undue experimentation by variations apparent to those of ordinary skill in the art in view of the teachings in this specification and the state of the art.
[0118] A desirable novel feature of the process of the invention is the selective formation of a 2-(5-halopyridyl) or 2-(5-halopyrimidinyl) magnesium halides, preferably 2-(5-halopyridyl) magnesium halides (e.g. 3 and 12, vide infra), and their subsequent reactions with the in situ generated E-Y-Z electrophiles. Below in Scheme 1, the addition of 2-(5-halopyridyl) magnesium halide 3 to the immonium salt 6 was carried out without the isolation of the immonium salt.
[0119] A non-limiting example for a compound of the formula (A) is the amine 1 shown in Scheme V.
[0120] Reaction intermediate (2) with a generic formula (B) above can be obtained as exemplified in Scheme VI below. Addition of a copper catalyst may be required for transformations involving certain types of electrophiles, for example the alkylation reaction of the Grignard intermediate with various alkyl halides and epoxides.
[0121] Examples of appropriate electrophiles are shown in the table below. Methods of making Y-Z electrophilic derivatives are within the skill in the art. Y component in Y-Z is a derivative of the Y of the formula (A) of the final product upon the addition of the electrophile to the Grignard intermediate. Products may be further derivatized to achieve the desired Y-Z. Such further transformations are within the skills in the art. A non-limiting example is shown below for a preferred embodiment of Z in the formula (A), i.e., the morpholino immonium salt 6. Reference in this regard may be made to Heaney, H.; Papageorgiou, G.; Wilkins, R. F. Tetrahedron 1997, 53, 294 1; Sliwa, H.; Blondeau, D. Heterocycles 1981, 16, 2159;.
[0122] In this example, E-Y-Z is compound 6, wherein morpholinyl represents Z and Y is —CH 2 — in the final product.
[0123] As described above, any electrophile represented by Y, possessing a Z component and compatible with Grignard type reactions are contemplated to be within the scope of the invention. Additional non-limiting examples of E-Y-Z are:
[0124] wherein E-Y is an aldehyde such as Z—CHO, thus Y in Formula (A) would be —CH(OH)—.
[0125] wherein NRR represent any of the above-listed Z amine moieties or heterocycles possessing a nitrogen heteroatom and Y can be alkylene such as —CH 2 —, X is a countervalent anion.
[0126] wherein E-Y is a branched or unbranched alkoxy possessing a halogen atom X and further linked to Z, such as ClCH 2 —O—Z.
[0127] wherein E-Y is a C 1-4 acyl halide such as formylchloride, NRR′ represents any of the above-listed Z amine moieties, or heterocycles possessing a nitrogen heteroatom. LG is an appropriate leaving group such as halogens. (see: Katritzky et al., J. Chem. Res. 1999, 3, 230.)
[0128] wherein E-Y is a haloester moiety such as chloroformate. X is an appropriate leaving group such as halogens or alkoxy groups. (see: Satyanarayana et al., Synth. Commun. 1990, 20 (21), 3273.)
[0129] 6. Z—Y—X
[0130] wherein an appropriate Z-Y is substituted by halogen X, preferably iodine, such as CH 3 I.
[0131] Addition of an appropriate Z attached to a reactive epoxide provides the hydroxy intermediate which is further derivatized to the desired Y component.
[0132] Acylation wherein Y is an acyl attached to Z may be accomplished via the appropriate acylation reagent such as the ester shown above wherein —OR is a known leaving group.
[0133] In another embodiment of the invention there is provided a process of making the compounds of formula (A):
[0134] wherein Ar and W are as described above;
[0135] and wherein for the formula (A):
[0136] Y is —CH 2 —; and
[0137] Z is chosen from:
[0138] heterocycle chosen from morpholinyl, thiomorpholinyl, piperidinyl and pyrrolidinyl each of the aforementioned Z are optionally substituted with one to three halogen, C 1-6 alkyl, C 1-6 alkoxy, C 1-3 alkoxy-C 1-3 alkyl, C 1-6 alkoxycarbonyl, aroyl, C 1-3 acyl, oxo, pyridinyl-C 1-3 alkyl, imidazolyl-C 1-3 alkyl, tetrahydrofuranyl-C 1-3 alkyl, nitrile-C 1-3 alkyl, nitrile, phenyl wherein the phenyl ring is optionally substituted with one to two halogen, C 1-6 alkoxy, di-(C 1-3 alkyl)amino, C 1-6 alkyl-S(O) m , or phenyl-S(O)m wherein the phenyl ring is optionally substituted with one to two halogen, C 1-6 alkoxy or di-(C 1-3 alkyl)amino;
[0139] or Z is optionally substituted with one to three one to three amino or amino-C 1-3 alkyl wherein the N atom is optionally independently di-substituted by aminoC 1-6 alkyl, C 1-3 alkyl, arylC 0-3 alkyl, C 1-5 alkoxyC 1-3 alkyl, C 1-5 alkoxy, aroyl, C 1-3 acyl, C 1-3 alkyl-S(O) m — or arylC 0-3 alkyl-S(O) m — each of the aforementioned alkyl and aryl attached to the amino group is optionally substituted with one to two halogen, C 1-6 alkyl or C 1-6 alkoxy;
[0140] or Z is optionally substituted with one to three aryl or heterocycle as hereinabove described in this paragraph each in turn is optionally substituted by halogen, C 1-6 alkyl or C 1-6 alkoxy;
[0141] or Z is amino wherein the N atom is optionally independently mono- or di-substituted by C 1-6 alkyl or C 1-3 alkoxyC 1-3 alkyl, C 1-6 alkyl branched or unbranched, C 1-6 alkoxy, nitrileC 1-4 alkyl, C 1-6 alkyl-S(O) m , aryl chosen from phenyl, pyridinyl, pyrimidinyl, pyridazinyl, pyrazinyl, imidazolyl, pyrazolyl, triazolyl, tetrazolyl, furanyl, thienyl and pyranyl each aryl being optionally substituted with one to three halogen, C 1-6 alkyl, C 1-6 alkoxy, di-(C 1-3 alkyl)amino, C 1-6 alkyl-S(O) m or nitrile, and phenyl-S(O) m , wherein the phenyl ring is optionally substituted with one to two halogen, C 1-6 alkoxy or mono- or di-(C 1-3 alkyl)amino;
[0142] said reaction comprising:
[0143] reacting a compound of the formula (C)
[0144] with a magnesium reagent of the formula R—MgX b ; said reaction taking place in a suitable aprotic solvent at −78° C. to RT, for a reaction time of ½ hour to 2 hours producing the Grignard compound (F):
[0145] wherein
[0146] X a , is halogen selected from Br and Cl, and X a is attached to the ring via the 4 or 5 position;
[0147] X b is halogen chosen from Br, Cl and I;
[0148] X c is I or Br;
[0149] W is CH, CCH 3 or N; and
[0150] R is aryl, C 1-6 alkyl or C 5-7 cycloalkyl;
[0151] subsequently reacting the Grignard compound from the prior step with a N,N-dialkylformamide such as DMF to form an aldehyde:
[0152] and isolating the aldehyde;
[0153] reacting the aldehyde with an appropriate Z group under nucleophilic addition conditions to provide the compound (D)
[0154] This transformation is within the skill in the art and involves reacting of the aldehyde and the appropriate Z component under acidic conditions such as HCl, AcOH, H 2 SO 4 etc, preferably AcOH, in a suitable solvent such as THF, methylene chloride, 1,2-dichloroethane, preferably 1,2-dichloroethane for 0.5-5 h (preferably 2 h) at about RT followed by in situ reduction for 0.5-5 h (preferably 2 h) to provide the product (D).
[0155] Subsequent addition of the NH 2 —Ar compound can be done as described hereinabove, to provide the final product compound of the formula (A) as described above in this embodiment of the invention. A non-limiting example of this embodiment of the invention is shown in Scheme VII.
[0156] In order that this invention be more fully understood, the following examples are set forth. These examples are for the purpose of illustrating preferred embodiments of this invention, and are not to be construed as limiting the scope of the invention in any way.
SYNTHETIC EXAMPLES
Example 1
[0157] Synthesis of 5-bromo-2-iodopyridine from 2,5-dibromopyridine
[0158] 2,5-Dibromopyridine (100 g) was suspended in acetonitrile (500 mL) at rt. NaI (94 g) and AcCl (45 mL) were added and the reaction was then gently refluxed for 3 h. An aliquot was analyzed by 1 H NMR and MS and the reaction was about 80% complete. The reaction was cooled to rt and quenched with a few mL of water and then K 2 CO 3 aqueous solution to pH 8. EtOAc (1.5 L) was added to extract the organic materials. The organic layer was washed with saturated NaHSO 3 solution, the brine, and then dried over MgSO 4 . Concentration gave crude material that was subjected to the same conditions for about 3 h at which time 1 H NMR showed that the reaction was greater than 97% complete. The same workup provided the crude material. The crude crystals were washed twice with CH 3 CN and dried in the oven. The yield was 95 g.
[0159] [0159] 1 H NMR (CDCl 3 , 400 MHz) δ 8.44 (s, 1H), 7.60 (d, J=8.26 Hz, 1H), 7.44 (d, J=8.25 Hz, 1H).
Example 2
[0160] Synthesis of 5-bromo-2-formylpyridine from 5-bromo-2-iodopyridine via the Grignard Intermediate
[0161] In a 22 L 3-neck round bottomed flask equipped with a mechanical stirrer, 1 kg (3.52 mol) of 2-iodo-5-bromopyridine was dissolved in 5 L of THF. The solution was cooled to about −15 to −10° C. 1.9 L (2 M, 380 mol, 1.08 eq) of i PrMgCl was added at a rate to keep the internal temperature below 0° C. The reaction mixture became a brown suspension. After the reaction mixture was stirred between −15 to 0° C. for 1 h, 400 mL (5.16 mol, 1.5 eq) of DMF was added at a rate to keep the internal temperature below 0° C. After stirring at this temperature for 30 min, the cooling bath was removed and the reaction was allowed to warm to room temperature over 1 h. The reaction mixture was then cooled to 0° C. and 4.0 L (7.74 mol, 2.2 eq) of 2 N HCl was added at a rate to keep the internal temperature below 25° C. The mixture was stirred for 30 min, then pH was raised from 1 to a pH 6-7 by adding about 150 mL of 2 N NaOH. The layers were separated and the THF layer was concentrated to give dark brown wet solids. The aqueous layer was extracted with 3 L of CH 2 Cl 2 . The CH 2 Cl 2 layer was used to dissolve the residue obtained from the THF layer, the resulting solution was washed with water (2×2 L), dried by stirring with MgSO 4 (400 g) for 30 min, and filtered. Concentration of the filtrate to dryness gave 583 g of the desired aldehyde as brownish-yellow solids (89% yield after air drying).
[0162] [0162] 1 H NMR (CDCl 3 , 400 MHz) δ 10.04 (d, J=0.68 Hz, 1H), 8.86 (t, J=0.52 Hz, 1H), 8.02 (dt, J=8.20, 0.68 Hz, 1H), 7.85 (d, J=8.48 Hz, 1H).
Example 3
[0163] Synthesis of 5-bromo-2-(4-morpholinylmethyl)pyridine from 5-bromo-2-iodopyridine via the Grignard Intermediate
[0164] To a solution of bis(1-morpholinyl)methane (130 mg) in THF (3 mL) at rt was added acetyl chloride (45 mL). The reaction was stirred for 1 h and cooled to 0° C.
[0165] In another flask, 5-bromo-2-iodopyridine (130 mg) was dissolved in THF (3 mL) at −40° C. The solution was treated with i PrMgCl (2 M in THF, 0.39 mL) at the same temperature for 15 min. Then the Grignard solution was cannulated into the immonium salt suspension generated above at 0° C. After the addition, the reaction mixture was stirred at rt for 1h and quenched with saturated NH 4 Cl solution. Extraction with CH 2 Cl 2 , drying over MgSO 4 , filtration and concentration gave a crude oil. This was further purified by column chromatography to afford the product in about 50% yield.
[0166] [0166] 1 H NMR (CDCl 3 , 400 MHz) δ 8.60 (s, 1H), 7.76 (d, J=8.24 Hz, 1H), 7.32 (d, J=8.64 Hz, 1H), 3.72 (m, 4H), 3.59 (s, 2H), 2.48 (m, 4H).
Example 4
[0167] Synthesis of 5-bromo-2-(4-morpholinyl)methylpyridine from 5-bromo-2-formylpyridine
[0168] To a solution of 500 g (2.688 moles) aldehyde in a 5 L of 1,2-dichloroethane at room temperature was added morpholine (1.15 eq, 3.09 moles, 269 ml) in one portion. The reaction temperature went up to 29° C. After stirring the reaction mixture for 15 min, acetic acid (2.1 eq, 5.6 moles, 323 mL) was added in one portion. The temperature rose to 31° C. It was stirred for 1.5 h at room temperature. Sodium triacetoxyborohydride (1.06 eq, 2.85 moles, 604 g) was added in 100 g portions every 10 min. The temperature was maintained between 35° C. and 46° C. by gentle cooling. It was stirred for an additional 2 h.
[0169] The reaction mixture was quenched with 4 N HCl keeping the temperature below 15° C. At the end of addition, the pH of aqueous phase was between 0 and 1 (˜2200 mL). The organic phase was separated and discarded. The aqueous phase was basified with 9 N NaOH (˜740 g NaOH) to pH ˜9.5 keeping the internal temperature below 15° C. The product was extracted with methylene chloride. Evaporation of the solvent gave pure amine (660 g, 2.57 moles).
Example 5
[0170] Synthesis of 5-Bromo-3-methyl-2-pyridinecarboxaldehyde
[0171] An example of the synthesis of a compound of formula (F) in which W is CR 3 (R 3 =methyl), and subsequent reaction with an electrophile is provided below and illustrated in Scheme VIII.
[0172] 2,5-Dibromo-3-picoline is commercially available or may be prepared from 2-amino-5-bromo-3-methylpyridine by standard diazotization followed by bromination in Br 2 /HBr. Acetyl chloride (0.68 mol, 52.7 mL) was added to a stirring solution of 2,5-dibromo-3-picoline (0.45 mol, 113 g) in acetonitrile (600 mL) followed by sodium iodide (1.66 mol, 250 g) and the reaction mixture was gently refluxed for 18 h. The cooled reaction mixture was filtered and the solid was washed with acetonitrile until colorless. It was suspended in methylene chloride and treated with aq. Na 2 CO 3 until the pH was 10-11. The organic layer was separated, dried over anhydrous sodium sulfate and concentrated to give a brown oil. It was subjected to iodination a second time as above (reflux time 6 h). A dark brown oil was obtained using the same work-up as above. A solution of this oil in hexane was treated with charcoal, filtered and concentrated to give a light brown oil. It slowly solidified on standing to give 5-bromo-2-iodo-3-methylpyridine as a light brown solid (95.0 g, 0.32 mol). Yield: 70%.
[0173] 2-Iodo-5-bromo-3-methylpyridine (250 mg) was dissolved in THF (4.0 mL). The solution was cooled to 0° C. i PrMgCl (2 M in THF, 0.5 mL) was added at a rate to keep the internal temperature below 5° C. After the reaction mixture was stirred at 0° C. for 1 h, DMF (0.13 mL) was added at 0° C. After stirring at this temperature for 30 min, the cooling bath was removed and the reaction was allowed to warm to room temperature over 1 h. The reaction mixture was hydrolyzed by a saturated aqueous NH 4 Cl solution. Then the aqueous layer was extracted with CH 2 Cl 2 . The CH 2 Cl 2 layer was dried over MgSO 4 and concentrated to give the desired aldehyde as a brownish-yellow solid (80% yield). | Disclosed are novel 2-(5-halopyridyl) and 2-(5-halopyrimidinyl) magnesium halides, processes of making and their use in the efficient synthesis in their respective 5-halo-2-substituted pyridines and pyrimidines. | 2 |
FIELD OF THE INVENTION
This invention relates to an electrical gauge and a method of gauge manufacture, and particularly for a gauge having a return-to-zero feature.
BACKGROUND OF THE INVENTION
Electrical gauges of the type used as indicator meters in automotive vehicles frequently are driven solely by electrical signals representing the parameter being measured so that when the current is turned off, as when the vehicle ignition is off, the gauge is left to float or drift to give an indication which is not relative to the real state of the parameter. This condition is not a serious matter since the apparent misinformation occurs only when the vehicle is not operating. It is considered to be desirable, however, to positively bias the meter to a zero indication when the ignition is turned off to avoid the impression that the gauge is unreliable or that the measured parameter has the indicated value,
It has been previously proposed to use a biasing magnet in a gauge to attract the magnetic armature to a zero value in the absence of signal current as indicated in the following U.S. patents. Pfeffer U.S. Pat. No. 2,668,945 uses a calibrating magnet which is adjusted by bending tabs or screw adjustment after meter assembly for each meter. Reenstra U.S. Pat. No. 4,492,920 incorporates a plurality of magnets in a bobbin to establish a restoring force to a fixed position. A compensating coil is used to counteract any effects of the magnets when signals are applied to the meter. Void U.S. Pat. No. 3,777,265 has a variable reluctance path adjusted individually by bending soft iron tabs for calibration. The drawbacks of requiring individual meter adjustment after assembly, a compensating coil, and limiting restoring force to a preset fixed direction lead to expensive assemblies and limited meter designs.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide a meter with a return-to-zero feature which requires no adjustment after assembly or any individual adjustment.
It is a further object of the invention to provide a method of manufacture of a meter having an accurate return-to-zero magnet requiring no individual adjustment.
The invention is carried out by an air core gauge having a bobbin defining a central cavity, an armature secured to the bobbin for rotation about an axis including a disc magnet in the cavity, an indicating pointer controlled by the armature, an annular biasing magnet fixed to the bobbin coaxially with the armature and magnetized in a predetermined direction to bias the disc magnet to a preset angular position, coils wound around the bobbin, and means for supplying current to the coils to energize the gauge, whereby the biasing magnet determines the gauge indication in the absence of coil current.
The method of the invention is carried out by manufacturing a return-to-zero gauge assembly having a pair of bobbin portions including armature journals, an annular biasing magnet, a magnetized armature, and coils comprising the steps of assembling an annular blank for the biasing magnet to one of the bobbin portions concentrically with a journal, and establishing a magnetizing field across the blank and its associated bobbin portion to magnetize the blank in a predetermined direction parallel to a diameter of the blank to form the biasing magnet, with the optional step of assembling the bobbin portions, the armature, and the coils prior to the magnetizing step to armature.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other advantages of the invention will become more apparent from the following description taken in conjunction with the accompanying drawings wherein like reference numerals refer to like parts and wherein:
FIG. 1 is a partly broken away isometric view of the meter according to the invention;
FIG. 2 is a cross-sectional view of a sub-assembly of the meter of FIG. 1;
FIG. 3 is an end view of the sub-assembly of FIG. 2 taken along lines 3--3; and
FIG. 4 is a cross-sectional view of the completed assembly of the meter according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in the drawings, the meter 10 according to the invention comprises a plastic bobbin 12 defining a cavity 14 containing a disc magnet 16 carried by a shaft 18 to form an armature 20 which is journaled in the bobbin, an annular biasing magnet 22 on the bobbin 12, coils 24 wound around the bobbin 12, four terminals 26 secured to the bobbin 12 and connected electrically to the coils 24, and a pointer 28 secured to an end of the shaft 18 which extends beyond the bobbin 12. The disc magnet 16 is a permanent magnet which is magnetized in the direction of a diameter of the disc.
The bobbin 12 is made of first and second complementary portions 30 and 32, each having a circular central portion 34 containing a recess 36 for defining the cavity 14 when the portions are mated. Four axially disposed posts 38 extend from the periphery of the central portions 34 of each bobbin portion 30, 32 to form lateral support for the coils 24. The terminals 26 extend axially through the posts to form connectors for the meter 10. Central hubs 40 protruding outwardly from each central portion 34 are apertured to serve as journals for the shaft 18. The first bobbin portion 30 has mounting lugs 42 extending radially outwardly from the posts 38 for securing the meter to a mounting surface and an indicator dial, not shown.
Many of the features described above are commonly used in air core gauges for instrument panel displays in automotive vehicles. In operation the coils carry current in response to the value of a parameter being measured to establish a magnetic field directed parallel to a diameter of the disc magnet 16. The disc magnet will align with the field to move the pointer 28 and provide a meter indication.
The biasing magnet 22 is a new feature of the subject meter and comprises an annulus of magnet material, preferably a polymer bonded ferrite, positioned on the outer surface of the first bobbin portion 30 concentric with the hub 40 and thus concentric with the shaft 18 and the disc magnet 16. In the course of meter design the preferred direction and strength of the biasing magnet 22 field is determined. Typically a magnet 0.75 mm thick having inner and outer diameters of 4.9 mm and 10 mm, respectively, has been successfully used. To precisely control the field of the biasing magnet 22, a blank of substantially non-magnetized material is fixed to the first bobbin portion by adhesive prior to bobbin assembly. Then the blank and the first bobbin portion are exposed to a magnetizing field 44 in the prescribed direction, as shown in FIG. 3, to accurately establish the biasing field direction relative to the bobbin structure. For the magnetizing step, the blank/bobbin portion sub-assembly is held in a fixture which can rotate to precisely position the blank in the magnetizing field. A magnetizing force H ci =10,000 oersteds is applied to the blank to form the magnet 22. The magnet strength is controlled by complete saturation of the magnet during charging. Typical magnet values are: residual induction B r =1700 gauss, coercive force H c =1550 oersteds and maximum energy product B d H d =0.75 megagauss-oersteds. After magnetizing the bias magnet 22, the armature 20 and the second bobbin portion 32 are assembled to the first portion 30 and the terminals 26 and coils 24 are added. The ends 46 of the terminals 26 are bent over and connected to the ends of the coils 24.
An alternative method of manufacture of the gauge starts with both the annular blank and the armature in an unmagnetized condition and assembling them with the bobbin portions and winding the coils before applying the magnetizing field. Then the biasing magnet and the armature are formed simultaneously by the magnetizing field. The pointer is then added with the coils energized by a predetermined current.
It will be seen that the method of forming a biasing magnet during assembly of a gauge allows the magnet direction to be accurately determined, even in mass production, so that individual adjustment or adjustment after assembly is not required, and that any direction of magnetic field can be chosen. It will also be apparent that such a meter with a return-to-zero feature can be made with low additional cost because of the inexpensive bias magnet material and the lack of individual adjustments. | An air core electrical gauge incorporates on the bobbin an annular biasing magnet magnetized in a direction to return the meter pointer to zero in the absence of a gauge driving current. A method of manufacturing the gauge includes magnetizing the biasing magnet after it is secured to a bobbin portion but optionally magnetizing the guage armature at the same time. | 8 |
The government has rights in this invention pursuant to Grant #R802,665 awarded by the United States Environmental Protection Administration.
BACKGROUND OF THE INVENTION
In textile terminology, the warp is the collection of lengthwise threads from which fabric is woven. That is to say, the warp is the thread which runs lengthwise of the loom. Typically, selected warp threads are raised by the heddles of the loom to allow the filling, or woof, to be carried between the alternate warp yarns. The alternate raising and lowering of the warps causes them to rub against one another, the rubbing causing abrasion of the threads. As they abrade, fine fibers are separated from the yarns, causing the yarns to cling together interfering with the passage of the shuttle. The warp yarns are also subjected to tensile and flexing forces which may cause them to break up during weaving.
This problem of abrasion of the warp in a loom has been dealt with by a process known as "slashing". When one slashes a warp, one applies to the warp threads a coating of size, which in effect glues loose fibrils to the body of the thread, and provides a degree of lubrication between the threads as they pass each other in the weaving operation. In early days of mechanized weaving, the sizing was applied to the warp on the loom by a man with a brush with a "slashing" motion. As modern high speed weaving was developed, the slashing step became a separate process. In the modern process, the warp is wound on a long mandrel called a "beam" in lengths of thousands of yards. Then the beam is unwound, the warp yarns being led through a machine called a "slasher". In the slasher, a solution of size material is applied to the threads. During slashing the yarns are passed over drying cylinders which remove the water and leave a coating of dry size on the yarn. The warp threads are separated one from another, and are rewound on another mandrel called the "loom beam". The loom beam itself is stored until a loom is ready to receive it for the weaving step.
In most cases, after a fabric has been woven, the warp size must be removed before the fabric is sent on to the finishing step, or to market. The step of removing the size is known as desizing. Typically, fabric from the loom is passed through a washing bath in which hot water dissolves the warp size. The cleaned fabric is dried and rewound. The wash water from the desizing bath, with its load of size washed out of the fabric, commonly must be treated before it is dumped into a nearby stream. Typical warp size is an organic material which, unless it is processed in a waste water treatment facility, will decompose in the stream, and rob the stream of dissolved oxygen, thereby creating a source of pollution. In technical language, the size creates "BOD" -- biological oxygen demand. The effluent from a large textile mill is therefore potentially a major source of stream pollution.
As a consequence of antipollution legislation, textile mills have been obliged to install expensive waste-treating plants, or else they have had to resort to special, and expensive, warp-sizing processes which are non-polluting to both air and water.
The substance most commonly used for a warp size is starch, which may be derived from any of several sources. The starch is first cooked, or gelatinized, which converts the starch into a viscous hydrophilic substance which will adhere to fibers of the warp threads, on which it is subsequently dried, and from which it can be readily removed, in the desizing step, in a hot water wash. The starch size may be modified by the addition of certain adjuncts as lubricants. The starch may be chemically modified to enhance certain of its properties. For example, the starch may be reacted with nitrogen-containing radicals to render the starch "soluble" in the sense that the starch can be readily dissolved in water and its gelatinous, viscous state, produced without previously cooking it. Although starch, and various modifications to it, makes a cheap and useful warp size, it cannot be reclaimed in the desizing step. The process of removing the starch from the woven fabric typically involves depolymerization of the starch with enzymes or other agents followed by washing away of the degradation products with water. The starch degradation products in the wash water are, of course, a total loss to the mill. Moreover, the wash water can no longer be discharged into a stream, as pointed out above, and therefore its disposal constitutes a major expense in the operation of the textile mill.
The disposal of desize wash water has become so great a problem that several radical alternatives to the conventional process have been proposed, and in some cases adopted. One solution to the problem is to dissolve a suitable size material in a nonflammable, non-aqueous solvent; for example, a chlorinated hydrocarbon. When warps slashed with such a solution are dried, the evaporated solvent must be recovered, for economy's sake and also to prevent air pollution. Then after weaving, fabric must be desized in the solvent, again requiring an expensive solvent recovery system. Finally, solvent must be reclaimed from the desize liquor by distillation, which step requires a large energy input.
Another approach to the problem involves using polyvinyl alcohol (PVA) dissolved in water. PVA in the desize wash liquor may be reclaimed for recycling. However, the reclamation step requires ultrafiltration, or reverse osmosis, an expensive and delicate process. Even though such reclamation plants cost millions of dollars, the disposal problem is so acute that several ultra-filtration plants are now in use.
The textile industry therefore needs a warp sizing process which will provide a suitable warp size, soluble in water, which can be recovered for recycling from the desizing wash liquor without the requirement of large amounts of energy, and without complex expensive process equipment.
SUMMARY OF THE INVENTION
An object of the invention is to provide a method for sizing textile warps with a water-soluble size which can be reclaimed from desizing liquor by changing the temperature of the desizing liquor.
Another object of the invention is to provide a textile warp size composition which, when dissolved in water, will enable reclamation of the size by changing the temperature of desize liquor and thereby forming a readily separable precipitate of the size.
These objects, and others which will be apparent to those skilled in the art of textile warp sizing, are obtained by using for a warp size a chemical which is soluble in water at one temperature and insoluble in water at a different temperature; and further by providing a process for changing the temperature of desize liquor to precipitate the chemical. One class of chemical compounds useful for the attainment of these objects comprises the hydroxypropylated polysaccharides.
A particularly useful hydroxypropylated polysaccharide is hydroxypropyl cellulose (HPC). HPC is soluble in cold water, making a viscous solution which forms an excellent warp size. Furthermore, HPC can be readily precipitated from desize wash liquor and recovered, simply by heating the desize liquor to 110° F and separating out the precipitated HPC. The supernatant liquor from which the HPC has been reclaimed may be recycled or discharged with a minimum of waste water, because it is essentially free of BOD.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic flow sheet of a process for desizing woven fabrics and reclaiming the warp size therefrom for recycle and reuse.
FIG. 2 is a molecular diagram of a cellulosic saccharide unit in which a 2° hydroxypropylether radical has replaced one of the three hydroxyl groups.
FIGS. 3A, 3B and 3C are graphs comparing performance of different warp sizes.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The embodiments described are exemplary of the invention only, and are not to be construed as limiting the invention as defined in the claims.
The hydroxypropylated polysaccharides (HPPS) have the peculiar property of dissolving in cold water, but in hot water, of precipitating from solution in a readily separable floc. HPPS also have excellent warp-sizing properties when coated on textile fibers and dried. In one embodiment illustrative of the invention, hydroxypropyl guar gum is used as a warp size. In another embodiment, hydroxypropyl starch is used.
The preferred HPPS is hydroxypropyl cellulose (HPC). HPC is marketed in several grades according to hydroxypropyl content and molecular weight. HPC suitable for warp size has molecular substitution giving products of from 20% to 80% by weight of hydroxypropoxyl content. A preferred grade of HPC manufactured by Hercules, Inc. is known in the trade as Klucel J.sup.(™). It has an hydroxypropoxyl content of about 73% and a molecular weight of about 200,000.
It is convenient to add to the warp size lubricants which are known to textile chemists to be useful adjuncts to a warp size. A preferred warp size formulation is the following:
Hydroxypropyl cellulose Hercules Klucel J: 125 lb.
Hydrophobic Lubricant: 5 lb.
Referring now to FIG. 1, the process will be described starting with the step of desizing woven fabric. The desizing step is conventional, except that the water used is kept at a temperature below 100° F. Preferably the water should be between 40° F and 80° F. 1 represents a roll of fabric to be desized. The fabric is led over rollers through the desizing tub 2, thence over dryers 3, and is rewound on mandrel 4.
Water level in the desizing tub is maintained by adding cold water at one end. Desize liquor--that is, water in which HPC, washed out of the fabric, has been dissolved -- is drawn off at the other end of the tub, at a rate which will maintain the concentration of HPC in the desize liquor at between 0.5% and 1.5%. Flow through the tub, which is compartmentalized, is counter-current to the direction of the fabric's motion.
The desize liquor is then put through a continuous drum filter 5, where particulate matter, such as fibers from the washed fabric, are removed.
In the next step the desize liquor is heated and the HPC precipitated in the form of a floc. Subsequent separation of the HPC is facilitated if the floc is coagulated by addition of an electrolyte such as sodium chloride at this point or into the desize washer or the size formulation. A preferred method of heating the desize liquor is to inject live steam into a vessel 6 containing the liquor until a temperature greater than 110° F is attained. In another embodiment the desize liquor is heated in a heat exchanger.
In the next step, a dispersion of precipitated HPC in water is separated from the desize liquor. The floc which forms when a solution of HPC is heated traps considerable water with it. Since the precipitated HPC is to be recycled as concentrated warp size solution, it is neither necessary nor desirable to completely separate HPC solids from trapped water. What is needed is a concentration of about 3 - 10% HPC in water. This is achieved by passing the hot desize liquor through a filtration medium such as nylon fabric. The Dual Cell Gravity dewatering unit of Permutit Company, division of Sybron Corporation 7 represents such a unit.
In anotherembodiment the hot desize liquor is kept in the tanks in which it was heated until the floculated HPC has settled, after which it is decanted and the supernatant water is discarded or recycled. In yet another embodiment the precipitated HPC is separated by passing the hot desize liquor through a centrifugal separator such as the type used to separate starch from gluten in corn refining.
The concentrated dispersion of precipitated HPC and water is turbid and free-flowing as long as its temperature is kept above 110° F. As the dispersion cools, the HPC begins to dissolve in the water. The solution will clarify and become viscous. It is important therefore to avoid stagnant volumes in the piping which conducts warm concentrated HPC dispersion where cooling could cause local plugging.
The warm, concentrated dispersion of HPC is pumped into make-up tank 8 for making a new supply of warp size. It is convenient, at this point, to add sufficient fresh HPC, or cold water, to bring the warp size composition to the required concentration. Finally the batch is agitated to speed solution of the HPC.
The freshly made batch of warp size is pumped into the slasher size box 9. Temperature must be below 100° F, and is preferably between 70° F and 90° F. Since viscosity and therefore pick-up by the warp threads varies with temperature, close attention is required.
The warp, wound on warp beams 10, is led through the size box of the slasher in conventional manner, passes over drying rolls 11 and is rewound on loom beam 12. The loom beam may be stored or even transported to another location for the weaving step.
In many cases, the steps of slashing and of weaving and desizing are physically separated in different plants. In these cases the process can be separated between the two plants along the line A--A'. When this is done, the reclaimed HPC is shipped from the desizing plant to the plant in which the warp yarns are slashed.
The following experiments were made to establish the effectiveness of HPC as a warp size:
Experiment #1
The effectiveness of an aqueous solution of HPC as a warp size was compared with the effectiveness of an aqueous solution of polyvinvyl alcohol (PVA). PVA is known to be one of the most effective warp sizes known to the art, although it is expensive relative to more common warp sizes such as the starches. Comparison was made of laboratory sized yarns at different add-on precentages of size. Samples were evaluated in terms of parameters standard in the art. Results are shown in graphical form in FIGS. 3A, 3B and 3C. In FIG. 3A, percentage increase in breaking strength over unsized cotton yarns is plotted against add-on percent (by weight of yarn) for HPC and PVA. In FIG. 3B, percent decrease in elongation is similarly plotted. The yarns must retain a certain minimum level of elongation to weave efficiently. In FIG. 3C, abrasion resistance is similarly plotted. (PVA has superior abrasion resistance because a sizing lubricant is required for its use.)
The graphs of FIGS. 3A, 3B and 3C show that HPC is the equivalent of PVA in effectiveness as a warp size on 100% cotton yarns. Of course, when the warp size is recovered and recycled the use of high add-on percentages is far less objectionable than it is when the warp size must be discarded.
Experiment #2
The tables below show the effect of HPC compared to the effect of PVA as a warp size when it is applied to yarns of 50% polyester and 50% cotton. The tables again show that HPC is generally the equivalent of PVA as a warp size.
TABLE 1______________________________________ Mean Break Percent increase Percent Factor in tenacity overSample Size add-on (oz. x counts) unsized control______________________________________Control0 - 363 --PVA* 7.0 384 6HPC 13.8 426 18______________________________________ *Griffwax.sup.(TM) sizing lubricant, 5% on weight of the PVA, was added t the PVA size formulation.
TABLE 2______________________________________ Mean Elong- % decrease in Percent ation at elongation fromSample Size add-on Break unsized control______________________________________Control0 - 11.2 --PVA* 7.0 7.9 30HPC 13.8 8.1 28______________________________________ *Griffwax.sup.(TM) sizing lubricant, 5% on weight of the PVA, was added t the PVA size formulation.
TABLE 3______________________________________ Percent Mean Abrasion ResistanceSample Size add-on (cycles to break)______________________________________Control0 - 67PVA* 7.0 10,000+HPC 13.8 5,491______________________________________ *Griffwax.sup.(TM) sizing lubricant, 5% on weight of the PVA, was added t the PVA size formulation.
Experiment #3
HPC was recovered from sized yarns, re-precipitated, and re-used as a warp size. Tensile strength, elongation, and abrasion resistance were the same for the reclaimed as for the virgin HPC.
The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, it being recognized that various modifications are possible within the scope of the invention. | A chemical, useful as a warp size, which is soluble in water at one temperature and insoluble at a different temperature, is applied to textile yarns in the process known as slashing. By manipulation of temperatures the chemical is reclaimed and recycled as a warp size. The water from the reclamation step may be recycled, or the water may be discharged with a minimum of waste treatment. | 3 |
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] The following application is filed on the same day as the following co-pending applications: “METHOD AND SYSTEM FOR HORIZONTAL COIL CONDENSATE DISPOSAL” by inventors Arturo Rios, Floyd J. Frenia, Jason Michael Thomas, Michael V. Hubbard, and Thomas K. Rembold (attorney docket number U75.12-003); “CONDENSATE PAN INSERT” by inventors Jason Michael Thomas, Floyd J. Frenia, Thomas K. Rembold, Arturo Rios, Michael V. Hubbard, and Dale R. Bennett (attorney docket number U75.12-005); “METHOD AND SYSTEM FOR VERTICAL COIL CONDENSATE DISPOSAL” by inventors Thomas K. Rembold, Arturo Rios, Jason Michael Thomas, and Michael V. Hubbard (attorney docket number U75.12-006); “CASING ASSEMBLY SUITABLE FOR USE IN A HEAT EXCHANGE ASSEMBLY” by inventors Arturo Rios, Thomas K. Rembold, Jason Michael Thomas, Stephen R. Carlisle, and Floyd J. Frenia (attorney docket number U75.12-007); “LOW-SWEAT CONDENSATE PAN” by inventors Arturo Rios, Floyd J. Frenia, Thomas K. Rembold, Michael V. Hubbard, and Jason Michael Thomas (attorney docket number U75.12-008); “CONDENSATE PAN INTERNAL CORNER DESIGN” by inventor Arturo Rios (attorney docket number U75.12-009); “VERTICAL CONDENSATE PAN WITH NON-MODIFYING SLOPE ATTACHMENT TO HORIZONTAL PAN FOR MULTI-POISE FURNACE COILS” by inventor Arturo Rios (attorney docket number U75.12-010); “CONDENSATE SHIELD WITH FASTENER-FREE ATTACHMENT FOR MULTI-POISE FURNACE COILS” by inventor Arturo Rios (attorney docket number U75.12-011); and “SPLASH GUARD WITH FASTENER-FREE ATTACHMENT FOR MULTI-POISE FURNACE COILS” by inventor Arturo Rios (attorney docket number U75.12-012), which are incorporated herein by reference.
BACKGROUND
[0002] The present invention relates to a casing assembly. More particularly, the present invention relates to a casing assembly suitable for use in a heat exchange assembly.
[0003] In a conventional refrigerant cycle, a compressor compresses a refrigerant and delivers the compressed refrigerant to a downstream condenser. From the condenser, the refrigerant passes through an expansion device, and subsequently, to an evaporator. The refrigerant from the evaporator is returned to the compressor. In a split system heating and/or cooling system, the condenser may be known as an outdoor heat exchanger and the evaporator as an indoor heat exchanger, when the system operates in a cooling mode. In a heating mode, their functions are reversed.
[0004] In the split system, the evaporator is typically a part of an evaporator assembly coupled with a furnace. However, some cooling systems are capable of operating independent of a furnace. A typical evaporator assembly includes an evaporator coil (e.g., a coil shaped like an “A”, which is referred to as an “A-frame coil”) and a condensate pan disposed within a casing. An A-frame coil is typically referred to as a “multi-poise” coil because it may be oriented either horizontally or vertically in the evaporator assembly.
[0005] During a cooling mode operation, a furnace blower circulates air into the casing of the evaporator coil assembly, where the air cools as it passes over the evaporator coil. The blower then circulates the air to a space to be cooled. Depending on the particular application, an evaporator assembly including a vertically oriented A-frame coil may be an up flow or a down flow arrangement. In an up flow arrangement, air is circulated upwards, from beneath the evaporator coil assembly, whereas in a down flow arrangement, air is circulated downward, from above the evaporator coil assembly.
[0006] Refrigerant is enclosed in piping that is used to form the evaporator coil. If the temperature of the evaporator coil surface is lower than the dew point of air passing over it, the evaporator coil removes moisture from the air. Specifically, as air passes over the evaporator coil, water vapor condenses on the evaporator coil. The condensate pan of the evaporator assembly collects the condensed water as it drips off of the evaporator coil. The collected condensation then typically drains out of the condensate pan through a drain hole in the condensate pan.
BRIEF SUMMARY
[0007] The present invention is a casing assembly suitable for use in a heat exchange assembly. The casing assembly includes a casing, which includes at least one interlocking interior corner. The interlocking corner strengthens the casing and helps maintain the integrity of the casing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1A is a perspective view of an evaporator assembly, which includes an evaporator coil and condensate pan disposed within a casing.
[0009] FIG. 1B is an exploded perspective view of the evaporator assembly of FIG. 1A .
[0010] FIG. 2A is a perspective view of a casing assembly, which includes a casing and a front deck.
[0011] FIG. 2B is a cross-sectional view of a left bottom portion of the casing of FIG. 2A .
[0012] FIG. 2C is a cross-sectional view of a rear bottom portion of the casing of FIG. 2A .
[0013] FIG. 2D is a cross-sectional view of a right bottom portion of the casing of FIG. 2A .
[0014] FIG. 3 is a bottom view of the casing of FIG. 2A , illustrating a flange configured to receive a vertical condensate pan.
[0015] FIG. 4 is a partial perspective view of an interlocking design between a left inner surface of the left bottom portion and a rear inner surface of the rear bottom portion of the casing of FIG. 2A .
[0016] FIG. 5 is a partial perspective view of an interlocking design between a right end of the front deck and a left flange of the left bottom portion of the casing assembly of FIG. 2A .
[0017] FIG. 6 is a plan view of a sheet of material that is used to form the casing of FIG. 2A .
DETAILED DESCRIPTION
[0018] FIG. 1A is a perspective view of evaporator assembly 2 , which includes casing 4 in accordance with the present invention, A-frame evaporator coil (“coil”) 6 , coil brace 8 , first delta plate 10 , second delta plate 12 , horizontal condensate pan 14 , drain holes 15 , vertical condensate pan 16 , drain holes 17 , first cover 18 , input refrigerant line 20 , and output refrigerant line 22 . When evaporator assembly 2 is integrated into a heating and/or cooling system, evaporator assembly 2 is typically mounted above an air handler. The air handler includes a blower that cycles air through evaporator assembly 2 . In a down flow application, the blower circulates air in a downward direction (indicated by arrow 24 ) through casing 4 and over coil 6 . In an up flow application, the blower circulates air in an upward direction (indicated by arrow 26 ) through casing 4 .
[0019] Coil 6 , condensate pan 14 , and condensate pan 16 are disposed within casing 4 , which is preferably a substantially airtight space for receiving and cooling air. That is, casing 4 is preferably substantially airtight except for openings 4 A and 4 B (shown in FIG. 1B ). In a down flow application, air is introduced into evaporator assembly 2 through opening 4 A and exits through opening 4 B. In an up flow application, air is introduced into evaporator assembly 2 through opening 4 B and exits through opening 4 A. In the embodiment shown in FIGS. 1A and 1B , casing 4 is constructed of a single piece of sheet metal that is folded into a three-sided configuration, and may also be referred to as a “wrapper”. In alternate embodiments, casing 4 may be any suitable shape and configuration and/or formed of multiple panels of material.
[0020] Coil 6 is a multi-poise A-frame coil, and may be oriented either horizontally or vertically. The vertical orientation is shown in FIGS. 1A and 1B . In a horizontal orientation, casing 4 is rotated 90° in a counterclockwise direction. Coil brace 8 is connected to air seal 28 and helps supports coil 6 when coil 6 is in its horizontal orientation.
[0021] Coil 6 includes first slab 6 A and second slab 6 B connected by air seal 28 . A gasket may be positioned between air seal 28 and first and second slabs 6 A and 6 B, respectively, to provide an interface between air seal and slabs 6 A and 6 B that is substantially impermeable to water. First and second delta plates 10 and 12 , respectively, are positioned between first and second slabs 6 A and 6 B, respectively. First slab 6 A includes multiple turns of piping 30 A with a series of thin, parallel plate fins 32 A mounted on piping 30 A. Similarly, second slab 6 B includes multiple turns of piping 30 B with a similar series of thin, parallel fins mounted on piping 30 B. Tube sheet 29 A is positioned at an edge of slab 6 A, and tube sheet 29 B is positioned at an edge of slab 6 B. Delta plates 10 and 12 , and air seal 28 may be attached to tube sheets 29 A and 29 B.
[0022] In the embodiment shown in FIG. 1A , coil 6 is a two-row coil. However, in alternate embodiments, coil 6 may include any suitable number of rows, such as three, as known in the art. Refrigerant is cycled through piping 30 A and 30 B, which are in fluidic communication with one another (through piping system 62 , shown in FIG. 1B ). As FIG. 1A illustrates, coil 6 includes input and output lines 20 and 22 , respectively, which are used to recycle refrigerant to and from a compressor (which is typically located in a separate unit from evaporator assembly 2 ). Refrigerant input and output lines 20 and 22 extend through first cover 18 . Evaporator assembly 2 also includes access cover 38 (shown in FIG. 1B ) adjacent to first cover 18 , and together, first cover 18 and access cover 38 fully cover the front face of evaporator assembly 2 (i.e., the face which includes first cover 18 ). Access cover 38 will be described in further detail in reference to FIG. 1B .
[0023] As discussed in the Background section, if the temperature of coil 6 surface is lower than the dew point of the air moving across coil 6 , water vapor condenses on coil 6 . If coil 6 is horizontally oriented, condensation from coil 6 drips into condensate pan 14 , and drains out of condensate pan 14 through drain holes 15 , which are typically located at the bottom of condensate pan 14 . If coil 6 is vertically oriented, condensate pan 16 collects the condensed water from coil 6 , and drains the condensation through drain holes 17 , which are typically located at the bottom of condensate pan 16 .
[0024] Because evaporator assembly 2 includes horizontal condensate pan 14 and vertical condensate pan 16 , evaporator assembly 2 is configured for applications involving both a horizontal and vertical orientation of coil 6 . In an alternate embodiment, evaporator assembly 2 is modified to be applicable to only a vertical orientation of coil 6 , in which case horizontal condensate pan 14 and brace 8 are absent from evaporator assembly 2 . In another alternate embodiment, evaporator assembly 2 excludes vertical condensate pan 16 such that evaporator assembly 2 is only applicable to horizontal orientations of coil 6 .
[0025] FIG. 1B is an exploded perspective view of evaporator assembly 2 of FIG. 1A . Front deck 39 and upper angle 40 are each connected to casing 4 with screws 41 . Another suitable method of connecting front deck 39 and upper angle 40 to casing 4 may also be used, such as welding, an adhesive or rivets. Front deck 39 and upper angle 40 provide structural integrity for casing 4 and provide a means for connecting front cover 18 and access cover 38 to casing 4 . Screw 43 attaches brace 8 (and thereby, air seal 28 ) to horizontal condensate pan 14 . Of course, other suitable means of attachment may be used in alternate embodiments. In addition to air seal 28 , air splitter 44 is positioned between first slab 6 A and second slab 6 B of coil 6 and is attached by tabs on tube sheets 29 A and 29 B of coil 6 .
[0026] Horizontal and vertical condensate pans 14 and 16 are typically formed of a plastic, such as polyester, but may also be formed of any material that may be casted, such as metal (e.g., aluminum). Horizontal condensate pan 14 slides into casing 4 and is secured in position by pan supports 46 . Tabs 46 A of pan supports 46 define a space for condensate pan 14 to slide into. When coil 6 is in a horizontal orientation (and casing 4 is rotated about 90° in a counterclockwise direction), coil 6 is positioned above horizontal condensate pan 14 so that condensation flows from coil 6 into horizontal condensate pan 14 . Air splitter 44 and splash guards 45 A and 45 B also help guide condensation from coil 6 into horizontal condensate pan 14 .
[0027] Condensation that accumulates in horizontal condensate pan 14 eventually drains out of horizontal condensate pan 14 through drain holes 15 . Gasket 52 A is positioned around drain holes 15 prior to positioning first cover 18 over drain holes 15 in order to help provide a substantially airtight seal between drain holes 15 and first cover 18 . First cover 18 includes opening 53 A, which corresponds to and is configured to fit over drain holes 15 and gasket 52 A. The substantially airtight seal helps prevent air from escaping from casing 4 , and thereby increases the efficiency of evaporator assembly 2 . Caps 56 A may be positioned over one or more drain holes 15 , such as when evaporator assembly 2 is used in an application in which coil 6 is vertically oriented.
[0028] Vertical condensate pan 16 slides into casing 4 and is supported, at least in part, by flange 48 , which is formed by protruding sheet metal on three-sides of casing 4 and top surface 39 A of front deck 39 . Specifically, bottom surface 16 A of condensate pan 16 rests on flange 48 and top surface 39 A of front deck 39 . Condensate pan 16 includes outer perimeter 49 , insert 50 , drain holes 17 (which are sealed by gasket 52 B) and plurality of ribs 54 .
[0029] One or more channels are positioned about outer perimeter 49 of vertical condensate pan 16 for receiving condensation from coil 6 . In the vertical orientation of coil 6 illustrated in FIGS. 1A and 1B , coil 6 is positioned above vertical condensate pan 16 to allow condensation to flow along one slab 6 A or 6 B and eventually into one or more of the channels along outer perimeter 49 of vertical condensate pan 16 . In this way, condensation collects in condensate pan 16 . In some applications, such as when coil 6 is a three row coil, insert 50 is positioned in condensate pan 16 to help shield coil 6 from condensate blow off from condensate pan 16 .
[0030] Evaporator assembly 2 includes features, such as ribs 54 and shield 58 , that are configured to help direct condensation into the one or more channels along outer perimeter 49 of vertical condensate pan 16 (when coil 6 is vertically oriented). Shield 58 is attached to tube sheet 29 A and is configured to both guide condensation into a channel along outer perimeter 49 of condensate pan 16 and help protect coil 6 from condensation blow-off, which occurs when condensation that is collected in condensate pan 16 is blown into the air stream moving through evaporator assembly 2 . A similar shield is attached to tube sheet 29 B.
[0031] Condensation that accumulates in vertical condensate pan 16 eventually drains out of vertical condensate pan 16 through drain holes 17 . Gasket 52 B is positioned around drain holes 17 prior to positioning first cover 18 over drain holes 17 in order to help provide a substantially airtight seal between drain holes 17 and first cover 18 . First cover 18 includes opening 53 B, which corresponds to and is configured to fit over drain holes 17 and gasket 52 B. The airtight seal helps prevent air from escaping from casing 4 , and thereby increases the efficiency of evaporator assembly 2 . Cap 56 B may be positioned over one or more drain holes 17 .
[0032] Piping system 62 fluidically connects piping 30 A of first slab 6 A and piping 30 B of second slab 6 B. Refrigerant flows through piping 30 A and 30 B, and is recirculated from and to a compressor through inlet and outlet tubes 20 and 22 , respectively. Specifically, refrigerant is introduced into piping 30 A and 30 B through inlet 20 and exits piping 30 A and 30 B through outlet 22 . As known in the art, refrigerant inlet 20 includes rubber plug 64 , and refrigerant outlet 22 includes strainer 66 and rubber plug 68 . Inlet 20 protrudes through opening 70 in first cover 18 and outlet 22 protrudes through opening 72 in first cover 18 . By protruding through first cover 18 and out of casing 4 , inlet 20 and outlet 22 may be connected to refrigerant lines that are fed from and to the compressor, respectively. Gasket 74 is positioned around inlet 20 in order to provide a substantially airtight seal around opening 70 . Similarly, gasket 76 is positioned around outlet 22 .
[0033] First cover 18 is attached to casing 4 with screws 78 . However, in alternate embodiments, other means of attachment are used, such as welding, an adhesive, or rivets. Further covering a front face of evaporator assembly 2 is access cover 38 , which is abutted with first cover 18 . Again, in order to help increase the efficiency of evaporator assembly 2 , it is preferred that joint 81 between first cover 18 and access cover 38 is substantially airtight. A substantially airtight connection may be formed by, for example, placing a gasket at joint 81 .
[0034] Access cover 38 is attached to casing 4 with screws 82 . However, in alternate embodiments, any means of removably attaching access cover 38 to casing 4 are used. Access cover 38 is preferably removably attached in order to provide access to coil 6 , condensate pan 16 , and other components inside casing 4 for maintenance purposes. One or more labels 84 , such as warning labels, may be placed on first cover 18 and/or access cover 38 .
[0035] FIG. 2A is a perspective view of casing assembly 86 in accordance with the present invention, which includes casing 4 and front deck 39 . Casing assembly 86 includes left internal rear corner 87 , right internal rear corner 88 , left internal front corner 89 , and right internal front corner 90 . Each corner 87 , 88 , 89 , and 90 includes an interlocking structure that increases the strength of casing assembly 86 , and increases the integrity of casing assembly 86 , such that casing assembly 86 is able to substantially withhold its shape during shipping and handling (e.g., installation). In each internal rear corner 87 and 88 , two surfaces intersect, and thereby interlock. In each internal front corner 89 and 90 , two surfaces mate together to interlock. The interlocking structure and design of each internal corner 87 , 88 , 89 , and 90 will be described in further detail in reference to FIGS. 4 and 5 .
[0036] Casing 4 includes left panel 92 , rear panel 94 , and right panel 96 . Left panel 92 of casing 4 includes left top portion 98 and left bottom portion 100 , while rear panel 94 of casing 4 includes rear top portion 102 and rear bottom portion 104 , and right panel 96 of casing 4 includes right top portion 106 and right bottom portion 108 . Left top portion 98 includes left lip 110 , which is folded inward (toward opening 4 B of casing 4 ) in order to tuck away edge 110 A of left lip 110 , which may be sharp. As previously discussed, in one embodiment, casing 4 is formed of sheet metal, which may form a sharp edge when cut. If edge 110 A of left lip 110 is sharp, certain problems may be presented. For example, if coil 6 (shown in FIGS. 1A and 1B ) comes into contact with left lip 110 , such as during manufacture of evaporator assembly 2 , a sharp edge 110 A may damage coil 6 .
[0037] Rear top portion 102 includes rear lip 112 , and right top portion 106 includes right lip 114 . Just as with left lip 110 , rear lip 112 and right lip 114 are folded inward in order to help minimize potentially sharp edges 112 A and 114 A (shown in phantom), respectively. In an alternate embodiment, each lip 110 , 112 , and 114 folds outward, such that edges 110 A, 112 A, and 114 A, respectively, point away from opening 4 B of casing 4 . In yet another alternate embodiment, each lip 110 , 112 , and 114 includes multiple folds.
[0038] FIG. 2B is a cross-section of left bottom portion 100 of left panel 92 of casing 4 taken along line 2 B- 2 B in FIG. 2A . Left bottom portion 100 is comprised of four generally planar surfaces: left outer surface 120 , left bottom surface 122 , left inner surface 124 , and left flange 126 . Left outer surface 120 and left inner surface 124 extend in a z-axis direction and left bottom surface 122 and left flange 126 extend in an x-axis direction. Outer, bottom, and inner surfaces 120 , 122 , and 124 , respectively, define a channel 128 . Casing 4 is often insulated in order to help maintain a temperature inside casing 4 within a preferred range. Insulation for left panel 92 of casing 4 may be introduced into channel 128 , which supports the insulation and helps to hold the insulation flush with left outer surface 120 . In an alternate embodiment, left bottom portion 100 includes at least one nonplanar surface.
[0039] As FIG. 2C illustrates, a cross-section of rear bottom portion 104 of casing 4 take along line 2 C- 2 C in FIG. 2A is similar to FIG. 2B . Rear bottom portion 104 is comprised of four generally planar surfaces: rear outer surface 130 , rear bottom surface 132 , rear inner surface 134 , and rear flange 136 . Rear outer surface 130 and rear inner surface 134 extend in a z-axis direction and rear bottom surface 132 and rear flange 136 extend in a y-axis direction. Rear outer, bottom, and inner surfaces 130 , 132 , and 134 , respectively, define a channel 138 . Insulation for rear panel 94 of casing 4 may be introduced into channel 138 , which supports the insulation and helps to hold the insulation flush with rear outer surface 130 . In an alternate embodiment, rear bottom portion 104 includes at least one nonplanar surface.
[0040] FIG. 2D is a cross-sectional view of right bottom portion 108 of casing 4 taken along line 2 D- 2 D in FIG. 2A . Again, FIG. 2D is similar to FIGS. 2B and 2C . Right bottom portion 108 is comprised of four generally planar surfaces: right outer surface 140 , right bottom surface 142 , right inner surface 144 , and right flange 146 . Right outer surface 140 and right inner surface 144 extend in a z-axis direction and right bottom surface 142 and right flange 146 extend in an x-axis direction. Right outer, bottom, and inner surfaces 140 , 142 , and 144 , respectively, define a channel 148 . Insulation for right panel 96 of casing 4 may be introduced into channel 148 , which supports the insulation and helps to hold the insulation flush with right outer surface 140 . In an alternate embodiment, right bottom portion 108 includes at least one nonplanar surface.
[0041] FIG. 3 is a bottom view of casing 4 of FIG. 2A . Left panel 92 is generally perpendicular to rear panel 94 , which is generally perpendicular to right panel 96 . Left, rear, and right flanges 126 , 136 , and 146 , respectively, extend around an inner perimeter of casing 4 and define opening 4 B in casing 4 , through which air is either introduced into or moved out of evaporator assembly 2 . Together with front deck 39 (shown in FIG. 2A ), left, rear, and right flanges 126 , 136 , and 146 , respectively, also define flange 48 ( FIG. 1B ), which is essentially a shelf that is configured to receive and support vertical condensate pan 16 .
[0042] In order to strengthen casing 4 and help maintain the integrity of casing 4 during shipping and handling of casing 4 and/or evaporator assembly 2 , casing 4 includes an interlocking design at left internal rear corner 87 and right internal rear corner 88 . At left internal rear corner 87 , left inner surface 124 of left bottom portion 100 and rear inner surface 134 of rear bottom portion 104 are designed to interlock. An embodiment of an interlocking design is shown in FIG. 4 , which is a partial perspective view of casing 4 , illustrating left internal rear corner 87 in which left panel 92 of casing 4 meets rear panel 94 of casing 4 . FIG. 4 also shows left flange 126 , which is adjacent to rear flange 136 . At left internal rear corner 87 shown in FIG. 4 , left inner surface 124 (shown in phantom) intersects with rear inner surface 134 (shown in phantom) at interface 151 to interlock left and rear bottom portions 100 and 104 , respectively. Specifically, left inner surface 124 interfaces with rear inner surface 134 , thereby distributing force between left and rear panels 92 and 94 , respectively, which may help prevent casing 4 from warping (i.e., substantially changing shape). Rear inner surface 134 (shown in FIG. 3 ) similarly interlocks with right inner surface 144 (shown in FIG. 3 ) at right internal rear corner 88 (shown in FIG. 3 ).
[0043] In the embodiment shown in FIG. 4 , left and rear inner surfaces 124 and 134 , respectively, interlock by interfacing. In alternate embodiments, any suitable means of interlocking left and rear inner surfaces 124 and 134 , respectively, to reinforce internal corners 87 and 88 ( FIG. 3 ) may be incorporated into casing 4 . For example, a mating design may be used. An example of a mating design includes, but is not limited to, a groove cut into rear inner surface 134 , into which left inner surface 124 closely fits.
[0044] Returning to FIG. 2A , front deck 39 includes top surface 39 A, bottom surface 39 B, left end 39 C, right end 39 D, and rear surface 39 E (shown in FIG. 5 ). Left end 39 C of front deck 39 interlocks with left flange 126 of left bottom portion 100 , while right end 39 D of front deck 39 interlocks with right flange 146 of right bottom portion 108 .
[0045] FIG. 5 is a partial perspective view showing an underside of casing assembly 86 of FIG. 2A . FIG. 5 illustrates an embodiment of an interlocking design between right end 39 D of front deck 39 and left flange 126 of left bottom portion 100 . In this embodiment, the interlocking design between left end 39 C of front deck 39 and right flange 146 of right bottom portion 108 is similar.
[0046] Front deck 39 includes flange 154 , which is integral with front deck surface 156 . Flange 154 and front deck surface 156 are cut at right end 39 D of front deck 39 , such that groove 158 is formed between flange 154 and front deck surface 156 . Left flange 126 of left bottom portion 100 of casing 4 is introduced into and engages with groove 158 to interlock left bottom portion 100 and front deck 39 . As FIG. 5 illustrates in phantom, front deck surface 156 extends underneath left flange 126 . Interlocking front deck 39 with left bottom portion 100 helps maintain the integrity of casing assembly 86 by reinforcing left front internal corner 89 of casing 4 . In alternate embodiments, other means of interlocking front deck 39 with left bottom portion 100 may be used.
[0047] As known in the art, casing 4 is typically connected to an air handler (e.g., a furnace), and in typical residential configurations, casing 4 is mounted on top of the air handler. Left, rear, and right inner surfaces 124 , 134 , and 144 , together with rear surface 39 E of front deck 39 define a space that is configured to receive or be introduced into a corresponding part of an air handler. Bottom surface 152 of casing 4 and bottom surface 39 B of front deck 39 typically engage with the air handler. Bottom surface 152 (shown in FIG. 2A ) of casing 4 remains substantially flat due to the increased strength of casing 4 , which is attributable to interlocking rear corners 87 and 88 . Similarly, bottom surface 39 B of front deck 39 remains substantially flat and in the same plane as bottom surface 152 of casing 4 because of interlocking internal front corners 89 and 90 . Together, substantially flat bottom surface 152 of casing 4 and bottom surface 39 B of front deck 39 help minimize any potential gaps that may be created at an interface between bottom surface 152 and the air handler. By minimizing gaps between bottom surface 152 and the air handler, the efficiency of evaporator unit 2 increases because the amount of air that is lost between evaporator unit 2 and the air handler is minimized.
[0048] As previously described, casing 4 may be formed from a single sheet of material, as shown in FIG. 6 . However, casing 4 may also be formed of multiple pieces that are attached together. FIG. 6 is a plan view of a single sheet 160 of material that is cut to form casing 4 of casing assembly 86 of FIG. 2A . The material may be, for example, sheet metal. Sheet 160 is folded to form the configuration of casing 4 shown in FIG. 2A . Fold lines are illustrated in phantom. Sheet 160 is folded about 90° along fold line 162 to define left panel 92 . Rear and right panels 94 and 96 , respectively, are defined by folding sheet 160 about 90° along fold line 164 . Lip 110 along left top portion 98 of left panel 92 is defined by folding sheet 160 about 90° along fold line 166 . Sheet 160 is then folded about 90° along fold line 168 . Finally, lip 110 is folded along line 169 as close to about 180° as possible in order to tuck edge 110 A inward. Lip 112 along rear top portion 102 of rear panel 94 is defined by folding sheet 160 about 90° along fold line 170 , and along fold line 172 about 90°. Lip 112 is then folded along fold line 173 as close to about 180° in order to tuck edge 112 A inward. Lip 114 along right top portion 106 of right panel 96 is defined by folding sheet 160 about 90° along fold line 174 , and folding along line 176 about 90°. Lip 114 is then folded along fold line 177 as close to about 180° in order to tuck edge 114 A inward.
[0049] Left outer surface 120 of left bottom portion 100 of left panel 92 of casing 4 is defined by folding along fold line 178 about 90°. As FIG. 6 illustrates, left outer surface 120 of left bottom portion 100 is integral with a majority of left panel 92 of casing 4 . In an alternate embodiment, left outer surface 120 is distinct from a majority of left panel 92 of casing 4 . Similarly, in an alternate embodiment, rear outer surface 130 and right outer surface 140 are distinct from rear panel 94 and right panel 96 , respectively. Left bottom surface 122 of left bottom portion 100 of left panel 92 of casing 4 is defined by folding about 90° along fold line 180 . Left inner surface and left flange 124 and 126 , respectively, of left bottom portion 100 of left panel 92 of casing 4 are defined by folding about 90° along fold line 182 . Similarly, rear outer, bottom, and inner surfaces 130 , 132 , and 134 , respectively, and flange 136 of rear bottom portion 104 of rear panel 94 of casing 4 are defined by folding about 90° along lines 184 , 186 , and 188 . Right outer, bottom, and inner surfaces 140 , 142 , and 144 , respectively, and right flange 146 of right bottom portion 108 of right panel 96 of casing 4 are defined by folding about 90° along lines 190 , 192 , and 194 .
[0050] Terminology, such as references to “left”, “right”, “front”, “rear”, “bottom”, and “top” throughout the description of the present invention is used for purposes of description, and not limitation. Specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as bases for teaching one skilled in the art to variously employ the present invention. While the present invention has been described with reference to evaporator unit 2 , a casing in accordance with the present invention is suitable for use with any heat exchanger.
[0051] Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. | A casing assembly suitable for use in a heat exchange assembly comprises a first panel including a first bottom portion, a second panel including a second bottom portion, and a third panel including a third bottom portion. The second bottom portion is interlocked with the first and third bottom portions. | 5 |
TECHNICAL FIELD
The present inventions relate to sand-control apparatus for use in subterranean wells, and in particular contemplate improved mechanical apparatus for attaching a sand-control screen jacket assembly to a base pipe and methods of using the same.
BACKGROUND OF THE INVENTIONS
The control of the movement of sand and gravel into a well bore has been the subject of much importance in the oil production industry. The introduction of sand or gravel into the wellbore commonly occurs under certain well conditions. The introduction of these materials into the well commonly causes problems including plugging and erosion. There have therefore been numerous attempts to prevent the introduction of sand and gravel into the production stream.
A common method to prevent the introduction of sand and gravel into the production stream has been a procedure known as gravel packing. In general, this involves placing a selected sand or gravel into the annular space between the wellbore and a base pipe introduced into the wellbore for that purpose. The base pipe contains perforations designed to allow well fluids to flow into the base pipe while excluding other material. A sand-control screen is commonly used in conjunction with a base pipe. An appropriately sized screen is commonly formed into a jacket and wrapped around the outside of the base pipe to prevent the entry of sand. Exemplary apparatus and methods of connecting a sand-control screen jacket assembly to a base pipe are disclosed in U.S. Pat. No. 5,931,232, which is assigned to this assignee and is incorporated herein for all purposes by this reference thereto.
One method of enhancing production in a well using a sand-control screen jacket assembly includes causing the radial expansion of the base pipe and surrounding screen jacket assembly by drawing a mechanical expansion tool through the base pipe. The radial expansion of the screen jacket assembly and base pipe is known to cause a related shrinkage in the length of both the base pipe and the screen jacket assembly. Since the base pipe is concentrically enclosed by the screen jacket assembly, the mechanical expander deployed in the base pipe necessarily causes greater expansion in the base pipe than in the surrounding screen jacket assembly. Correspondingly, the base pipe undergoes a greater contraction in length relative to the screen jacket assembly. This differential change in length causes problems such as cracking at the junction between the screen jacket assembly and the base pipe and can lead to the introduction of sand and gravel into the production stream.
Due to the aforementioned problems with the introduction of sand and gravel into the production stream, a need exists for apparatus and methods providing a robust mechanical sand-controlling, longitudinally moveable connection between a sand-control screen jacket assembly and a base pipe. Such a connection should withstand downhole production conditions including radial expansion and the related differential longitudinal contraction of the base pipe and sand-control screen jacket assembly.
SUMMARY OF THE INVENTIONS
In general, the inventions provide apparatus and methods for connecting a sand-control screen jacket assembly to a base pipe while providing for longitudinal movement of the screen jacket assembly relative to the base pipe.
The apparatus employs a substantially tubular screen jacket assembly having a first ring affixed to at least one end. A second ring is affixed to the outer surface of the base pipe of the screen jacket assembly wherein the first and second rings have sand-controlling overlapping portions defining a longitudinally movable joint. The joint has a stop integral with the overlapping portions of the first and second rings, which prevents the possibility of longitudinal separation of the screen shroud and base pipe.
According to one aspect of the invention the stop comprises a plurality of corresponding screws and slots in the respective overlapping portions of the first and second rings.
According to another aspect of the invention, the stop comprises correspondingly opposed surfaces of the respective overlapping portions of the first and second rings.
According to yet another aspect of the invention, the ring affixed to the base pipe is attached by a plurality of fasteners such as set screws.
According to still other aspects of the invention, the screen jacket assembly has one or more longitudinally deformable pleats or slots.
According to another aspect of the invention, the screen jacket assembly has one or more radially expandable pleats.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings are incorporated into and form a part of the specification to illustrate several examples of the present inventions. These drawings together with the description serve to explain the principals of the inventions. The drawings are only for the purpose of illustrating preferred and alternative examples of how the inventions can be made and used and are not to be construed as limiting the inventions to only the illustrated and described examples. The various advantages and features of the present inventions will be apparent from a consideration of the drawings in which:
FIG. 1 is a longitudinal cross-sectional view of a sand-control screen jacket assembly mechanically connected to a base pipe;
FIG. 2 is a close-up longitudinal cross-sectional view of another example of an embodiment of a sand-control screen jacket assembly mechanically connected to a base pipe;
FIG. 3 is a close-up longitudinal cross-sectional view of yet another example of an embodiment of a sand-control screen jacket assembly mechanically connected to a base pipe;
FIG. 4 is a close-up longitudinal cross-sectional view of still another example of an embodiment of a sand-control screen jacket assembly mechanically connected to a base pipe;
FIG. 5 is a close-up longitudinal cross-sectional view of an example of an embodiment of a sand-control screen jacket assembly mechanically connected to a base pipe;
FIG. 6 is a close-up longitudinal cross-sectional view of an example of an embodiment of a sand-control screen jacket assembly mechanically connected to a base pipe;
FIG. 6A is a transverse cross-sectional view taken along line A—A of FIG. 6;
FIG. 6B is a transverse cross-sectional view taken along line B—B of FIG. 6;
FIG. 7 is a close-up longitudinal cross-sectional view of an example of another embodiment of a sand-control screen jacket assembly connected to a base pipe.
FIG. 8 is a close-up longitudinal cross-sectional view of an example of another embodiment of a sand-control screen jacket assembly connected to a base pipe.
FIG. 9 is a close-up longitudinal cross-sectional view of an example of another embodiment of a sand-control screen jacket assembly connected to a base pipe.
DETAILED DESCRIPTION
The present inventions are described by reference to drawings showing one or more examples of how the inventions can be made and used. In these drawings, reference characters are used throughout the several views to indicate like or corresponding parts.
In the description which follows, like or corresponding parts are marked throughout the specification and drawings with the same reference numerals, respectively. The drawings are not necessarily to scale and the proportions of certain parts have been exaggerated to better illustrate details and features of the invention. In the following description, the terms “upper,” “upward,” “lower,” “below,” “downhole”, “longitudinally” and the like, as used herein, shall mean in relation to the bottom, or furthest extent of, the surrounding wellbore even though the wellbore or portions of it may be deviated or horizontal. Correspondingly, the “transverse” or “radial” orientation shall mean the orientation perpendicular to the longitudinal orientation. “Longitudinally moveable”, in particular, means movement with a longitudinal component, although a transverse component may be present as well. In the discussion which follows generally cylindrical well, pipe and tube components are assumed unless expressed otherwise. The term “sand-control” used herein means the exclusion of particles larger in cross section than a chosen size, whether sand, gravel, mineral, soil, organic matter, or a combination thereof.
Referring now to FIGS. 1 through 9 the general structure of a sand-control screen jacket assembly connection 10 utilizing the present inventive concepts is shown. It will be obvious to those skilled in the arts that the opposite end (not shown) of the screen jacket assembly 20 may be constructed in any conventional manner or in the same manner as the end described. A base pipe 12 is threadably connected to a collar 14 at either end. Each collar 14 is in turn connected to a pipe string (not shown) used in a subterranean well. The base pipe 12 has a plurality of perforations 18 through which fluids in the well enter the interior of the base pipe 12 . The number and configuration of the perforations 18 is not critical to the invention so long as a balance between fluid production and pipe integrity is maintained. A sand-control screen jacket assembly 20 concentrically surrounds the base pipe 12 . The sand-control screen jacket assembly 20 has one or more concentric screens 21 , with or without a layer of packed sand between concentric screen layers, and typically, a surrounding screen shroud 22 . The exact configuration of the screen jacket assembly is not critical to the invention and may be varied by those skilled in the arts according to well conditions. For example, the number and mesh sizes of screen may be varied, or the shroud may be omitted entirely. The screen jacket assembly may be radially expandable. Some examples of variations in the configuration of the screen, shroud, and screen jacket assembly, are further discussed below.
The preferred embodiment of the invention shown with an unexpanded screen jacket assembly in FIG. 2 has a substantially tubular screen shroud 22 with a first ring 24 affixed to one end, preferably by a weld 26 . A second ring 28 is affixed to the outer surface of the base pipe 12 , also preferably by a weld 26 . In this embodiment, the second ring 28 is preferably made of a plurality of segments 30 (FIG. 1) captured in a groove 32 provided for this purpose in the base pipe 12 . The first and second rings 24 , 28 have respective overlapping portions 25 , 27 . The corresponding overlapping portions 25 , 27 define a longitudinally slidable joint 34 sufficiently close-fitting to exclude sand particles of a size to also be excluded by the screen 21 , but not necessarily fluid tight. As the base pipe 12 and screen jacket assembly 20 are radially expanded with corresponding differential changes in length, the overlapping portions 25 , 27 of the joint 34 slide longitudinally with respect to one another while maintaining their sand-controlling fit. An elastomeric seal element 33 may be inserted at slidable joint 34 . The longitudinal separation of the screen jacket assembly 20 and the base pipe 12 is prevented by a stop 36 , preferably an integral portion of the second ring 28 .
FIG. 3 depicts an example of another embodiment of an apparatus using the invention. The screen jacket assembly connection 10 in FIG. 3 has a substantially tubular screen shroud 22 with a first ring 24 affixed to one end, preferably by a weld 26 . The embodiment using the invention depicted in FIG. 3 has a second ring 38 attached to the base pipe 12 with a weld 26 . Additionally, the groove 32 of FIG. 2 is omitted from the embodiment of FIG. 3 . An alternative configuration of the first ring 24 is also shown in FIG. 3 . The first and second rings 24 , 38 have respective overlapping portions 25 , 37 . The corresponding overlapping portions 25 , 37 define a longitudinally slidable joint 34 sufficiently close-fitting to exclude sand particles of a size to also be excluded by the screen 21 , but not necessarily fluid tight. As the base pipe 12 and screen jacket assembly 20 are radially expanded with corresponding differential changes in length, the overlapping portions 25 , 37 of the joint 34 slide longitudinally with respect to one another while maintaining their sand-controlling fit. An elastomeric seal element 33 may be inserted at slidable joint 34 . The longitudinal separation of the screen jacket assembly 20 and the base pipe 12 is prevented by a stop 36 , preferably an integral portion of the second ring 38 .
FIG. 4 depicts an example of another embodiment of an apparatus using the invention. The embodiment shown in FIG. 4 has a substantially tubular screen shroud 22 with a first ring 24 affixed to one end, preferably by a weld 26 . A second ring 40 is attached to the base pipe 12 with a plurality of set screws 41 . A longitudinally slidable joint 34 is defined by the inner surface 25 of the first ring 24 and the corresponding outer surface 13 of the base pipe 12 . The longitudinally slidable joint 34 is sufficiently close-fitting to exclude sand particles of a size to also be excluded by the screen 21 , but not necessarily fluid tight. As the base pipe 12 and screen jacket assembly 20 are radially expanded with corresponding differential changes in length, the overlapping portions 25 , 13 of the joint 34 slide longitudinally with respect to one another while maintaining their sand-controlling fit. An elastomeric seal element 33 may be inserted at slidable joint 34 . The longitudinal separation of the screen jacket assembly 20 and the base pipe 12 is prevented by the stop 36 defined by the transverse alignment of the first ring 24 and second ring 40 .
An alternative embodiment using the invention is shown in FIG. 5. A substantially tubular screen shroud 22 has a first ring 54 affixed to one end, preferably by a weld 26 . Alternatively, the first ring 54 may be integral to shroud 22 . A second ring 55 is affixed to the outer surface of the base pipe 13 , also preferably by a weld 26 . The first and second rings 54 , 55 have respective overlapping portions 56 , 57 . The corresponding overlapping portions 56 , 57 define a longitudinally slidable joint 34 sufficiently close-fitting to exclude sand particles of a size to also be excluded by the screen 21 , but not necessarily fluid tight. As the base pipe 12 and screen jacket assembly 20 are radially expanded with corresponding differential changes in length, the overlapping portions 56 , 57 of the joint 34 slide longitudinally with respect to one another while maintaining their sand-controlling fit. An elastomeric seal element 33 may be inserted at slidable joint 34 . The longitudinal separation of the screen jacket assembly 20 and the base pipe 12 is prevented by stop assembly 36 , preferably made from a plurality of corresponding screws 58 and slots 59 in the respective overlapping portions 56 , 57 of the first and second rings 54 , 55 .
FIG. 6 illustrates an alternative embodiment using the invention. The screen 21 has longitudinal pleats 61 to facilitate radial expansion. More extensive pleats or corrugations may also be provided for added surface area. As in the embodiments described with reference to FIGS. 1-5, the embodiment of FIG. 6 may be used with screen jacket assemblies 20 made with various combinations of screen 21 layers and a screen shroud 60 . The embodiment has an end connection assembly 63 with a first ring 64 welded to the base pipe 12 . A second ring 65 has a captured portion 66 captured between an overlapping portion 67 of the first ring and the base pipe 12 . The corresponding overlapping portions 66 , 67 define a longitudinally slidable joint 34 sufficiently close-fitting to exclude sand particles of a size to also be excluded by the screen 62 , but not necessarily fluid tight. As the base pipe 12 and screen jacket assembly 20 are radially expanded with corresponding differential changes in length, the overlapping portions 66 , 67 of the joint 34 slide longitudinally with respect to one another while maintaining their sand-controlling fit. An elastomeric seal element 33 may be inserted at slidable joint 34 . The second ring 65 has an integral transition portion 68 welded to the screen jacket assembly 20 . As can best be seen in FIG. 6A, taken in cross section along line A—A of FIG. 6, the captured portion 66 of the second ring 65 is cylindrical in cross section where it meets the base pipe 12 . FIG. 6B, taken in cross-section along line B—B of FIG. 6, illustrates that the transition portion 68 of the second ring is pleated or corrugated in cross-section where it is welded to the screen jacket assembly 20 . A third ring 69 having a transition portion substantially similar to that of the second ring 65 may be welded to the opposite, preferably downhole, end of the screen jacket assembly 20 and the surface 13 of the base pipe 12 . Alternatively, both ends of the screen jacket assembly may employ an end connection assembly 63 .
It will be clear to those skilled in the art that the structure shown and described with referrence to rings 65 , 66 or 69 in FIG. 6 can be adapted for the use of longitudinally pleated screens or shrouds in combination with any of the above-described embodiments shown and discussed with reference to FIGS. 1-5.
FIG. 7 depicts yet another alternative embodiment of a screen shroud 70 using the invention. This embodiment incorporates longitudinally deformable slots 71 in the screen shroud 70 . Of course, the embodiment shown and described may be used with a screen jacket assembly made with various combinations of screen and screen shroud layers. The shroud 70 is welded 26 at its end portions 72 to the base pipe 12 . The inner surface 73 of the end portions 72 of the shroud 70 containing the transverse slots 71 is in flush contact with the outer surface 13 of the base pipe 12 . The transverse slots 71 are designed to facilitate longitudinal movement of the shroud 70 relative to the base pipe 12 defining a longitudinally, deformably slidable joint 34 sufficiently close-fitting to exclude sand particles of a size to also be excluded by the screen 21 , but not necessarily fluid tight. As the base pipe 12 and screen jacket assembly 20 are radially expanded with corresponding differential changes in length, the transverse slots 71 of the joint 34 deform longitudinally while maintaining their sand-controlling fit. An elastomeric seal element 33 may be inserted at slidable joint 34 . As in the other embodiments described herein, a screen 21 is captured between the shroud 70 and the base pipe 12 . Of course, the exact orientation and location of the slots is not critical to the invention so long as the slots are configured to incorporate the property of longitudinal movability, for example, helical slots may be used. Optionally, spacer rods 74 may be included between the screen 21 and base pipe 12 to facilitate fluid flow.
FIGS. 8 and 9 depict other alternative embodiments using the invention with a screen jacket assembly 20 having a screen shroud 80 concentrically surrounding one or more screens 21 . The screen shroud 80 has one or more longitudinally deformable pleats 82 . The exact orientation and location of the pleats 82 is not critical to the invention so long as the pleats are configured to incorporate the property of longitudinal deformability, for example, transverse pleats 82 or helical pleats may be used. The pleated screen shroud 80 shown is welded 26 to the base pipe at either end 84 , capturing the screen 21 and allowing space 86 for sliding movement at the ends 84 . The pleats 82 may be arranged on the shroud 80 overlapping the screen 21 , as shown in FIG. 9, such that the pleats 82 act as a spacer, maintaining fluid flow space 90 between the screen shroud 80 and screen 21 .
Further referring to FIGS. 8-9, the pleats 82 are designed to facilitate longitudinal movement of the shroud 80 relative to the base pipe 12 defining a longitudinally, deformably slidable joint 34 sufficiently close-fitting to exclude sand particles of a size to also be excluded by the screen 21 , but not necessarily fluid tight. As the base pipe 12 and screen jacket assembly 20 are radially expanded with corresponding differential changes in length, the pleats 82 of the shroud 80 deform longitudinally while maintaining their sand-controlling fit. As in the other embodiments described herein, a screen 21 is captured between the shroud 80 and the base pipe 12 . Of course, the exact orientation and location of the pleats is not critical to the invention so long as the pleats are configured to incorporate the property of longitudinal deformability, for example, helical pleats may be used. Optionally, spacer rods 74 may be included between the screen 21 and base pipe 12 to facilitate fluid flow.
The embodiments shown and described above are only exemplary. Many details are often found in the art such as: screen mesh size, configurations and materials, the use of longitudinal rods or other spacers between a screen and another surface, or the use of a packed sand layer between screen layers. Therefore, many such details are neither shown nor described. It is not claimed that all of the details, parts, elements, or steps described and shown were invented herein. Even though numerous characteristics and advantages of the present inventions have been set forth in the foregoing description, together with details of the structure and function of the inventions, the disclosure is illustrative only, and changes may be made in the detail, especially in matters of shape, size and arrangement of the parts within the principles of the inventions to the full extent indicated by the broad general meaning of the terms used in the attached claims.
The restrictive description and drawings of the specific examples above do not point out what an infringement of this patent would be, but are to provide at least one explanation of how to make and use the inventions. The limits of the inventions and the bounds of the patent protection are measured by and defined in the following claims. | Disclosed are apparatus and methods for movably securing a radially expandable sand-control screen jacket assembly to a base pipe. The screen jacket assembly is connected to the base pipe with a longitudinally moveable, sand-controlling joint. In use, the joint slides maintain a sand-controlling seal after radial expansion of the sand-control screen jacket assembly. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to Danish Patent Application No. PA201600211, filed Apr. 8, 2016, which application is herein incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to the preparation of N-(2-(6-fluoro-1H-indol-3-yl)-ethyl)-3-(2,2,3,3-tetrafluoropropoxy)-benzylamine, INN-name idalopirdine, and pharmaceutically acceptable salts thereof.
BACKGROUND ART
[0003] N-(2-(6-fluoro-1H-indol-3-yl)-ethyl)-3-(2,2,3,3-tetrafluoropropoxy)-benzylamine is a potent and selective 5-HT6 receptor antagonist which is currently in clinical development. Its chemical structure is depicted below as Compound (I):
[0000]
[0004] The synthesis of N-(2-(6-fluoro-1H-indol-3-yl)-ethyl-(2,2,3,3-tetrafluoropropoxy)-benzylamine, its use for the treatment of disorders such as cognitive dysfunction disorders, and pharmaceutical compositions comprising this substance are disclosed in U.S. Pat. No. 7,157,488 which further describes the preparation of the corresponding mono-hydrochloride salt.
[0005] An improved method for the manufacture of Compound (I) or salt thereof is disclosed in international patent application WO2011/076212.
[0006] Further, WO2016/091997 discloses the synthesis of N-(2-(6-fluoro-1H-indol-3-yl)-ethyl)-3-(2,2,3,3-tetrafluoropropoxy)-benzylamine by use of a supported Ni-catalyst with the use of sodiumborohydride as a reducing agent.
[0007] The final steps in the preparation of Compound (I) or pharmaceutically acceptable salts thereof as disclosed in WO2011/076212 are outlined in Scheme A:
[0000]
[0008] The synthesis of Compound (IV) can conveniently be carried out as outlined below:
[0000]
[0009] The synthesis of Compound (IV) comprises the following steps:
1) Subjecting 2,2,3,3-tetrafluoro-1-propanol to tosylation to yield Compound (VIII); 2) and reacting Compound (VIII) in a displacement reaction with 3-hydroxybenzaldehyde in the presence of a base to yield Compound (IV).
[0012] The steps in the synthesis of Compound (I) as described above in scheme A consist of:
1) Hydrogenation of Compound (II) in the presence of a catalyst to obtain Compound (III), and isolation as L-(+)-tartaric acid salt (1:1) thereof (Step 1, Scheme A) 2) liberating Compound (III) from the L-(+)-tartaric acid salt (1:1) thereof (Step 2, Scheme A) to form the free base of Compound (III) 3) reacting the free base of Compound (III) with Compound (IV) in the presence of a reductant, specifically sodium borohydride to form Compound (I) (Step 3, Scheme A) 4) forming the HCl-salt (1:1) of Compound (I) (Step 4, Scheme A).
[0017] However, the reduction with sodium borohydride in step 3 suffers from a number of drawbacks:
a) Long quenching times b) Large amounts of waste are generated c) Many unit operations (e.g. layer washings) d) The formation of alcohol Compound (IX) also occurs in step 3 due to reduction of Compound (IV) with sodium borohydride, which leads to lowering of the yield of Compound (I):
[0000]
e) The formation of stable boron-amine complexes, such as Compound (X), which are not easily converted into Compound (I) or removed:
[0000]
f) The formation of enol ether Compound (XI) (E- and/or Z-isomer) which resides as an impurity in Compound (I) and salts thereof:
[0000]
[0024] Therefore, a more clean and productive process for the formation of Compound (I) is desirable. Such a process has been developed, and is disclosed in this patent application.
SUMMARY OF THE INVENTION
[0025] The present invention discloses a further development of the above discussed process where, in this new process, Compound (III) and Compound (IV) are reacted to form the imine Compound (V) which subsequently is reduced to form Compound (I) by hydrogenation, thus avoiding the use of sodium borohydride.
[0026] In one embodiment of the invention is disclosed a process for the preparation of Compound (V)
[0000]
[0000] comprising the following steps:
1) Mixing Compound (III) and Compound (IV) in a solvent or solvent mixture, with or without azeotropical separation of water 2) Isolating the precipitated Compound (V).
[0029] In another aspect of the invention is disclosed a process for the preparation of Compound (I) or a pharmaceutically acceptable salt thereof comprising the steps of:
1) Forming Compound (V) from Compound (III) and Compound (IV) in a solvent or solvent mixture with or without removal of water and precipitating and isolating Compound (V) as a solid:
[0000]
2) Reacting Compound (V) with hydrogen in the presence of a transition metal catalyst in a solvent or solvent mixture to form Compound (I)
3) Isolating Compound (I), optionally as a salt.
[0033] Isolated compound (V) can be obtained with a high purity (>99% UV area HPLC), even when starting from Compound (III) with a low purity (around 92% UV area HPLC).
[0034] In another aspect of the invention is disclosed a process for the preparation of Compound (I) or a pharmaceutically acceptable salt thereof comprising the steps of:
1) Forming Compound (V) from Compound (III) and Compound (IV) in a solvent or solvent mixture 2) Reacting the mixture with hydrogen in the presence of a transition metal catalyst in a solvent or solvent mixture to form Compound (I) 3) Isolating Compound (I), optionally as a salt.
DETAILED DESCRIPTION OF THE INVENTION
[0038] The process of the present invention takes advantage of the use of hydrogen as reductant instead of sodium borohydride. The disclosed process has the advantages discussed above and generates less waste, is cheaper, and allows for an easier isolation of Compound (I) or pharmaceutically acceptable salts thereof, compared to the use of the reductant sodium borohydride as described in WO2011/076212.
[0039] Also, fewer steps (and hence, unit operations in the plant) are needed in the process of the present invention compared to process for obtaining Compound (I) as described in WO2011/076212, since there is no need to isolate the L-(+)-tartaric acid salt (1:1) of Compound (III), and workup of Compound (I) is easier.
[0040] Another advantage is that in the formation of Compound (I) via hydrogenation of Compound (V), as disclosed herein, byproducts Compound (IX), Compound (X) and Compound (XI) are not observed.
[0041] Hydrogenation of Compound (V) provides Compound (I) with a good purity, such as more than 95% or even more than 99%, measured as UV area HPLC. Surprisingly, hydrogenation of Compound (V) with certain transition metal catalysts (e.g. Pd/C) disclosed herein yields Compound (I) with either non-detectable or very low amounts of byproduct Compound (VI) resulting from a N-debenzylation reaction of Compound (I):
[0000]
[0042] Upon salt formation the purity of compound (I) can be further improved, If necessary the salt can be recrystallized and the purity is improved further (>99.7% UV area HPLC).
[0043] Thus, in an embodiment (E1) the present invention relates to a process for the preparation of N-(2-(6-fluoro-1H-indol-3-yl)-ethyl)-3-(2,2,3,3-tetrafluoropropoxy)-benzylamine (Compound (I)), and pharmaceutically acceptable salts thereof, comprising the steps of:
1) forming Compound (V) from Compound (III) and Compound (IV) in a solvent or solvent mixture with or without removal of water, and 2) reacting Compound (V) with hydrogen in the presence of a transition metal catalyst in a solvent or a solvent mixture with or without the presence of an acid to form Compound (I), and 3) optionally adding an acid to precipitate Compound (I) as a salt.
[0047] In another embodiment (E2) of the present invention is disclosed a process for the preparation of Compound (I) and pharmaceutically acceptable salts thereof comprising the following steps:
1) forming Compound (V) from Compound (III) and Compound (IV) in a solvent or solvent mixture with or without removal of water, and 2) cooling the mixture to precipitate Compound (V) as a solid, and isolating Compound (V) 3) reacting Compound (V) with hydrogen in the presence of a transition metal catalyst in a solvent or a solvent mixture, with or without the presence of an acid to form Compound (I), and 4) optionally adding an acid to precipitate Compound (I) as a salt.
[0052] In a first particular embodiment of any of embodiment (E1) and (E2) Compound (V) is formed in an alcoholic solvent in step 1 of the any of the embodiments.
[0053] In a more particular embodiment of the previous embodiment the alcoholic solvent is IPA.
[0054] In a second particular embodiment of any of embodiment (E1) and (E2) Compound (V) is formed in a hydrocarbon solvent in step 1 of the any of the embodiments.
[0055] In a more particular embodiment of the previous embodiment the solvent is toluene or heptane or a solvent mixture of toluene and heptane.
[0056] In a more particular embodiment of the previous embodiment the heptane is n-heptane.
[0057] In a third embodiment (E3) the temperature of the reaction mixture in which Compound (V) (step 1) is formed is between 0° C. and 100° C., preferably between 40° C. and 100° C.
[0058] In a more particular embodiment of the previous embodiment the temperature of the reaction mixture is between 60° C. and 80° C., such as between 70° C. and 80° C., in particular about 75° C.
[0059] In a fourth embodiment (E4) precipitation of Compound (V) (step 2 of (E2)) is done by cooling the mixture to between −10° C. and 30° C.
[0060] In a more particular embodiment of the previous embodiment the mixture is cooled to room temperature, such as 15° C. to 30° C. in order to precipitate Compound (V).
[0061] In a fifth embodiment (E5) Compound (V) is obtained with a purity above 99% (measured as UV area HPLC) starting from Compound (III) and Compound (IV) having a purity in the range of 90%-99% (measured as UV area HPLC), such as 90%-95% (measured as UV area HPLC).
[0062] In an embodiment (E6) of any of embodiments (E1) and (E2) the hydrogenation is carried out in a solvent comprising an ether, ester, alcohol, or hydrocarbon or a solvent mixture of any of the aforementioned solvents.
[0063] In a particular embodiment of the previous embodiment the hydrogenation is carried out in solvent or solvent mixture which is chosen from the group consisting of THF, EtOAc, IPA and toluene, or mixtures thereof.
[0064] In an embodiment (E7) of any of embodiments (E1) and (E2) water is removed in step 1 by azeotropic distillation.
[0065] In an embodiment (E8) of any of embodiments (E1) and (E2) the hydrogenation of Compound (V) is carried out at a hydrogen pressure of 1 bar to 10 bar, such as 1 bar to 8 bar, such as 2 bar to 6 bar. In a particular embodiment the pressure is 1 bar.
[0066] In an embodiment (E9) of embodiment (E1) and (E2) the hydrogenation of Compound (V) is carried out in the temperature range 0° C. to 100° C., such as between 20° C. and 80° C., such as between 20° C. and 60° C., such as between 20° C. and 40° C., such as between 20° C. and 30° C.
[0067] In a particular embodiment of the previous embodiment the hydrogenation is carried out at room temperature, such as in the range of 15° C. to 30° C.
[0068] In a particular (E10) embodiment of the embodiments (E1) and (E2) the transition metal catalyst comprises a metal selected from the group consisting of iridium, rhodium, platinum, ruthenium, copper and palladium.
[0069] In a more particular embodiment of the previous embodiment the hydrogenation is carried out in the presence of a transition metal catalyst supported on any of silicium oxide, alumina, carbon or mixtures thereof.
[0070] In a particular embodiment (E11) of the previous embodiment the hydrogenation is carried out in the presence of palladium supported on carbon (Pd/C).
[0071] In a more particular embodiment of the previous embodiment the hydrogenation is carried out in the presence of palladium supported on carbon (Pd/C) with a loading (in mol %) between 0.05 and 0.1.
[0072] In an embodiment the hydrogenation is carried out in the presence of an acid additive.
[0073] In a particular embodiment of the previous embodiment the hydrogenation is carried out in the presence of an acid chosen from the group consisting of AcOH, MsOH, TFA, HCl, and sulfuric acid.
[0074] In a more particular embodiment of the previous embodiment the hydrogenation is carried out in the presence of an acid chosen from AcOH or MsOH.
[0075] In an embodiment (E12) of embodiments (E1) and (E2) Compound (I) is precipitated as a salt by addition of an acid to obtain the corresponding acid addition salt.
[0076] In a particular embodiment of the previous embodiment Compound (I) is precipitated as a pharmaceutically acceptable acid addition salt.
[0077] In a particular embodiment of the previous embodiment Compound (I) is precipitated as the 1:1 HCl salt.
[0078] Compound (I) forms pharmaceutically acceptable acid addition salts with a wide variety of organic and inorganic acids and include the physiologically acceptable salts which are often used in pharmaceutical chemistry. Such salts are also part of this invention. Such salts include the pharmaceutically acceptable salts listed in Berge, S. M. et al., J. Pharm. Sci., 1977, 66, 1-19, which are known to the skilled artisan. Typical inorganic acids used to form such salts include hydrochloric, hydrobromic, hydriodic, nitric, sulfuric, phosphoric, hypophosphoric, metaphosphoric, pyrophosphoric, and the like. Salts derived from organic acids, such as aliphatic mono and dicarboxylic acids, phenyl substituted alkanoic acids, hydroxyalkanoic and hydroxyalkandioic acids, aromatic acids, aliphatic and aromatic sulfonic acids, may also be used. Such pharmaceutically acceptable salts thus include chloride, bromide, iodide, nitrate, acetate, phenylacetate, trifluoroacetate, acrylate, ascorbate, benzoate, chlorobenzoate, dinitrobenzoate, hydroxybenzoate, methoxybenzoate, methylbenzoate, o-acetoxybenzoate, isobutyrate, phenylbutyrate, α-hydroxybutyrate, butyne-1,4-dicarboxylate, hexyne-1,4-dicarboxylate, caprate, caprylate, cinnamate, citrate, formate, fumarate, glycollate, heptarioate, hippurate, lactate, malate, maleate, hydroxymaleate, malonate, mandelate, mesylate, nicotinate, isonicotinate, oxalate, phthalate, teraphthalate, propiolate, propionate, phenylpropionate, salicylate, sebacate, succinate, suberate, benzenesulfonate, p-bromobenzenesulfonate, chlorobenzene-sulfonate, ethylsulfonate, 2-hydroxyethylsulfonate, methylsulfonate, naphthalene-1-sulfonate, naphthalene-2-sulfonate, naphthalene-1,5-sulfonate, p-toluenesulfonate, xylenesulfonate, tartrate, and the like.
[0079] The following abbreviations are used throughout the description:
“ND” is not detected. “IPA” is 2-propanol “THF” is tetrahydrofuran “EtOAc” is ethyl acetate “AcOH” is acetic acid “MsOH” is methanesulfonic acid “TFA” is trifluoroacetic acid “DEA” is diethylamine “aq” is aqueous. “rt” is room temperature. “approx.” is approximately “min” is minutes “h” is hours “g” is grams. “mL” is milliliter. “w/w” is weight per weight. “v/v” is volume per volume. “LC-MS” is liquid chromatography-mass spectrometry “HPLC” is high performance liquid chromatography “Pd/C” is palladium on charcoal. “Pt/C” is platinum on charcoal. “Rh/Alumina” is rhodium on aluminium oxide. “Ru/C” is ruthenium on carbon “Ir/CaCO 3 ” is iridium on calcium carbonate “Cu/C” is copper nanoparticles in charcoal “PRICAT™” is the trademark for a series of supported catalysts with/without added promotors, from Johnson Matthey Ltd. “Arbocell BC200™” is the trademark for fibrous cellulose from J. Rettenmaier & Sohne GmbH.
Experimental Section
General Experimental
[0107] Unless otherwise stated, all reactions were carried out under nitrogen. Reactions were monitored by LC-MS. All reagents were purchased and used without further purification. NMR spectra were recorded at 500 or 600 MHz ( 1 H NMR), and calibrated to the residual solvent peak. The following abbreviations are used for NMR data: s, singlet; bs, broad singlet; d, doublet; t, triplet; m, multiplet. Coupling constants are rounded to nearest 0.5 Hz.
LC-MS Method:
[0108] Acquity UPLC BEH C18 1.7 μm column; 2.1×50 mm operating at 60° C. with flow 1.2 mL/min of a binary gradient consisting of water+0.1% formic acid (A) and acetonitrile+5% water+0.1% formic acid (B). UV detection at 254 nm.
HPLC Method:
[0109] Zorbax Bonus-RP 5 μm column, 2.6×250 mm operating at 30° C. with flow 1.0 mL/min of a binary gradient consisting of water and acetonitrile, with 0.5% DEA added, buffered to pH 2.3 with TFA. UV detection at 280 nm.
Compound List:
[0000]
(I): 2-(6-fluoro-1H-indol-3-yl)-N-(3-(2,2,3,3-tetrafluoropropoxy)benzyl)ethan-1-amine
(II): 2-(6-fluoro-1H-indol-3-yl)acetonitrile
(III): 2-(6-fluoro-1H-indol-3-yl)ethan-1-amine
(IV): 3-(2,2,3,3-tetrafluoropropoxy)benzaldehyde
(V): (E)-N-(2-(6-fluoro-1H-indol-3-yl)ethyl)-1-(3-(2,2,3,3-tetrafluoropropoxy)phenyl)methanimine
(VI): 1-methyl-3-(2,2,3,3-tetrafluoropropoxy)benzene
(VII): 2-(6-fluoro-1H-indol-3-yl)-N,N-bis(3-(2,2,3,3-tetrafluoropropoxy)benzyl)ethan-1-amine
(VIII): 2,2,3,3-tetrafluoropropyl 4-methylbenzenesulfonate
(IX): (3-(2,2,3,3-tetrafluoropropoxy)phenyl)methanol
(X): N-(2-(6-fluoro-1H-indol-3-yl)ethyl)-N-(3-(2,2,3,3-tetrafluoropropoxy)benzyl)boranamine
(XI): 2-(6-fluoro-1H-indol-3-yl)-N-(3-((2,3,3-trifluoroprop-1-en-1-yl)oxy)benzyl)ethan-1-amine
Example 1: Synthesis of Compound (V) from Compound (III) and Compound (IV)
[0121]
In IPA as Solvent:
[0122] A mixture of Compound (III) (78 g, 0.438 mol) and Compound (IV) (114 g, 0.483 mol) in IPA (1480 mL) was heated at 70-75° C. for 3 h with stirring. The reaction mixture was then cooled to 40° C. with stirring, and seeded with Compound (V) and then subsequently allowed to cool slowly to rt over a period of 2 h, and stirred overnight at rt. The resulting suspension was filtered, and the filtercake was washed with IPA (100 mL) and dried in vacuum at 40° C. to yield Compound (V) (142 g, 82%) as a solid, with >99% purity according to 1 H NMR analysis.
[0123] Analytical data for Compound (V): 1 HNMR (600 MHz, CDCl 3 ) δ H 3.14 (t, J=7.0 Hz, 2H), 3.92 (t, J=7.0 Hz, 2H), 4.38 (t, J=12.0 Hz, 2H), 6.07 (tt, J=5.0, 53.0 Hz, 1H), 6.88 (dt, J=2.5, 9.0 Hz, 1H), 6.99 (s, 1H), 7.00 (dd, J=2.5, 8.5 Hz, 1H), 7.02 (dd, J=2.5, 9.5 Hz, 1H), 7.50 (d, J=7.5 Hz, 1H), 7.34 (d, J=8.0 Hz, 1H), 7.35 (m, 1H), 7.54 (dd, J=5.5, 8.5 Hz, 1H), 8.00 (bs, 1H), 8.12 (s, 1H); 13 C NMR (150 MHz, DMSO-d 6 ) δ C 26.9, 62.1, 65.4 (t, J=30.0 Hz), 97.5 (d, J=26.0 Hz), 108.1 (d, J=24.5 Hz), 109.1 (tt, J=34.0, 248.5 Hz), 112.0, 114.3, 114.6 (tt, J=27.0, 248.5 Hz), 117.9, 119.8 (d, J=10.5 Hz), 122.4 (d, J=3.0 Hz), 123.3, 124.3, 130.1, 136.2 (d, J=12.5 Hz), 138.1, 157.7, 160.1 (d, J=236.0 Hz), 160.8.
In Toluene as Solvent:
[0124] A mixture of Compound (III) (4.50 g, 25.3 mmol) and Compound (IV) (5.96 g, 25.3 mmol) in toluene (45 mL) was heated at reflux for 2 h and water was removed by azeotropical distillation with Dean-Stark water apparatus (volume ˜10 mL) attached. The mixture was cooled slowly to rt with stirring, and the formed suspension was filtered. The filtercake was washed with toluene (10 mL), and dried in vacuum at 40° C. to yield Compound (V) (7.68 g, 70%) as a solid.
Example 2: Synthesis of Compound (V) from Crude Compound (II)
[0125]
[0126] To a solution of crude Compound (II) (10.0 g, 57.4 mmol, 96% UV purity in LC-MS) in aq. ammonia (65 mL, 24% w/w) and IPA (35 mL) was added nickel catalyst (PRICAT type 55/5P from Johnson Matthey Ltd., 2.99 g, 30% w/w) at rt. The mixture was hydrogenated at 4 bar for 20 h at 50° C. The mixture was cooled and filtered through Arbocell BC 200™. The mixture was evaporated to dryness, and more IPA (100 mL) was added. The mixture was again evaporated to dryness to yield crude Compound (III). The crude Compound (III) (92% UV purity in LC-MS) was dissolved together with Compound (IV) (13.6 g, 57.4 mmol) in IPA (75 mL), and the mixture was heated at 75° C. for 1.5 h. The mixture was cooled with stirring to 45° C. and seeded with Compound (V), and further cooled slowly with stirring to rt, and stirred overnight. The mixture was then cooled at 0° C. for 1 h with stirring, and filtered cold. The filtercake was washed with IPA (10 mL) and dried in vacuum at 40° C. to yield Compound (V) (17.8 g, 78%) as a solid, with >99% purity according to 1 H NMR analysis.
Example 3: Screening of Catalysts in the Hydrogenation of Compound (V)
General Procedure (for Details, See Table 1-3):
[0127] To a solution of Compound (V) in solvent (2 mL) was added catalyst and any additive and the mixture was hydrogenated in an Endeavor hydrogenation apparatus (from Biotage AB) for 24 h. The reaction mixture was subsequently analysed by LC-MS.
[0000]
TABLE 1
Screening of iridium, rhodium, platinum and ruthenium catalysts
Entry
Catalyst
Loading 1
Solvent
Pressure 2
Temperature 3
(III) 4
(IV) 4
(VI) 4
(VII) 4
(I) 4
1
Ir/CaCO 3 5
0.5
EtOAc
4
60
<1
<1
ND
ND
98
2
Ir/CaCO 3 5
0.5
IPA
4
60
<1
<1
ND
ND
98
3
Ir/CaCO 3 5
0.5
Toluene
4
60
<0.5
<0.5
ND
ND
99
4
Ir/CaCO 3 5
0.5
IPA-
4
60
<0.5
<0.5
ND
ND
99
toluene 7
5
5% Rh/Al 6
2
THF
1
25
16
67
ND
ND
16
6
5% Rh/Al 6
2
EtOAc
1
25
16
65
ND
ND
19
7
5% Rh/Al 6
2
IPA
1
25
15
63
ND
ND
22
8
5% Rh/Al 6
2
Toluene
1
25
18
77
ND
ND
5
9
5% Rh/Al 6
2
IPA-
1
25
12
47
ND
ND
41
toluene 7
10
Pt/C 8
0.1
THF
4
25
ND
ND
ND
ND
>99
11
Pt/C 8
0.1
EtOAc
4
25
1
3
ND
ND
94
12
Pt/C 8
0.1
IPA
4
25
ND
ND
ND
ND
>99
13
Pt/C 8
0.1
Toluene
4
25
ND
ND
ND
ND
>99
14
Pt/C 8
0.1
IPA-
4
25
ND
ND
ND
ND
>99
toluene 7
15
Ru/C 9
0.5
Toluene
4
90
18
74
ND
1
7
16
Ru/C 9
0.5
Toluene
4
100
18
74
ND
1
7
17
Ru/C 9
0.5
Toluene
4
110
17
60
ND
3
20
18
Ru/C 9
1.0
Toluene
4
110
12
40
ND
6
42
19
Ru/C 9
2.0
Toluene
4
110
5
5
ND
8
82
1 In mol %;
2 In bar;
3 In ° C.;
4 Yields (in %) from LC-MS analysis at 254 nm (UV);
5 Type 30 from Johnson Matthey Ltd.;
6 Type 524 from Johnson Matthey Ltd.;
7 1:1 v/v mixture;
8 Type 128 M from Johnson Matthey Ltd.;
9 Type 600 from Johnson Matthey Ltd.
[0000]
TABLE 2
Screening of copper catalysts 1
Entry
Catalyst
Loading 2
Solvent
(III) 3
(IV) 3
(VI) 3
(VII) 3
(I) 3
1
PRICAT CU 50/8
15
THF
18
76
ND
5
1
2
PRICAT CU 50/8
15
EtOAc
10
47
ND
3
40
3
PRICAT CU 50/8
15
IPA
3
0
ND
12
78
4
PRICAT CU 50/8
15
Toluene
18
77
ND
ND
5
5
PRICAT CU 50/8
15
IPA-
19
78
ND
ND
3
Toluene 4
6
PRICAT CU 60/8
15
THF
17
73
ND
~1
9
7
PRICAT CU 60/8
15
EtOAc
15
63
ND
ND
22
8
PRICAT CU 60/8
15
IPA
17
66
ND
ND
16
9
PRICAT CU 60/8
15
Toluene
16
75
ND
~1
6
10
PRICAT CU 60/8
15
IPA-
19
80
ND
<1
<1
Toluene 4
11
Cu/C 5
100
Toluene
4
38
2
ND
54
12
Cu/C 5
100
EtOH
6
40
2
3
50
13
Cu/C 5
100
EtOAc
6
34
2
2
57
14
Copper powder 6
100
THF
19
80
ND
ND
~1
15
Copper powder 6
100
EtOAc
4
21
ND
ND
74
16
Copper powder 6
100
IPA
ND
ND
ND
Trace
95
17
Copper powder 6
100
Toluene
18
79
ND
ND
~2
18
Copper powder 6
100
IPA-
12
48
ND
3
37
Toluene 4
19
Copper
100
THF
ND
ND
ND
ND
94
nanopowder 7
20
Copper
100
EtOAc
17
60
0
3
20
nanopowder 7
21
Copper
100
IPA
ND
ND
ND
ND
75
nanopowder 7
22
Copper
100
Toluene
ND
ND
ND
ND
>97%
nanopowder 7
23
Copper
100
IPA-
ND
ND
ND
ND
86
nanopowder 7
Toluene 4
1 All reactions performed at 4 bar pressure and 100° C.;
2 In % w/w relative to Compound (V);
3 Yields (in %) from LC-MS analysis at 254 nm (UV);
4 1:1 v/v mixture;
5 3% w/w copper nanoparticles in carbon, from Sigma-Aldrich Inc., item #709107;
6 From Sigma-Aldrich Inc., item #292583, +45 μM;
7 Type Cu N100 from Tekmat Inc.
[0000]
TABLE 3
Screening of palladium catalysts 1
Entry
Catalyst
Loading 2
Additive
Solvent
Temperature 3
(III) 4
(IV) 4
(VI) 4
(VII) 4
(I) 4
1
5% Pd/C 5
0.5
None
IPA-
25
2
ND
~1
ND
95
Toluene 6
2
5% Pd/C 5
0.1
None
THF
25
ND
ND
ND
ND
99
3
5% Pd/C 5
0.1
None
EtOAc
25
<1
1
ND
ND
98
4
5% Pd/C 5
0.1
None
IPA
25
3
13
ND
ND
84
5
5% Pd/C 5
0.1
None
Toluene
25
11
51
ND
ND
37
6
5% Pd/C 5
0.1
None
IPA-
25
ND
ND
ND
ND
>99
Toluene 6
7
5% Pd/C 5
0.05
None
IPA-
25
14
40
ND
ND
46
Toluene 6
8
5% Pd/C 5
0.05
None
IPA-
50
Trace
3
ND
ND
97
Toluene 6
9
5% Pd/C 5
0.05
None
IPA-
80
ND
ND
ND
ND
>99
Toluene 6
10
5% Pd/C 5
0.1
AcOH
IPA-
25
2
3
ND
ND
94
(2 eq)
Toluene 6
11
5% Pd/C 5
0.05
AcOH
IPA-
25
2
3
ND
ND
95
(2 eq)
Toluene 6
12
5% Pd/C 5
0.05
MsOH
IPA-
25
~0.5
ND
ND
ND
98
(2 eq)
Toluene 6
13
Pd-Cu/C 7
1
None
IPA-
25
~1
4
ND
ND
96
Toluene 6
1 All reactions were performed at 1 bar pressure;
2 In mol %;
3 In ° C.;
4 Yields (in %) from LC-MS analysis at 254 nm (UV);
5 Type 338 from Johnson Matthey Ltd.;
6 1:1 v/v mixture;
7 Type A701023-4 from Johnson Matthey Ltd.
Example 4: Synthesis of Compound (I) as HCl-Salt from Compound (V)
[0128] A mixture of Compound (V) (10.0 g, 25.2 mmol) and 5% Pd/C catalyst (type 5R338 from Johnson Matthey Ltd., 59.4% w/w water, 0.265 g, 0.050 mmol) in toluene (50 mL) and IPA (50 mL) was hydrogenated at rt and 1 bar for 3 h. The reaction mixture was filtered through Arbocell BC 200™, and the filtrate was evaporated to dryness to yield Compound (I). Compound (I) was dissolved in IPA (30 mL) and toluene (70 mL), and aq. HCl (2.7 mL, 32.8 mmol, 37% w/w) was added dropwise at rt with vigorous stirring. Then more toluene (100 mL) was added and the mixture was concentrated to approx. 50% of the original volume. The formed suspension was filtered, and the precipitate was washed with toluene, and dried in vacuum at 40° C. to yield Compound (I) as HCl-salt (1:1) (10.3 g, 94%) as a solid, with 99% UV purity in LC-MS analysis.
Example 5: Synthesis of Compound (I) as HCl-Salt from Compound (III) and (IV)
[0129] To a mixture of Compound (III) (4.50 g, 25.3 mmol) and Compound (IV) (5.96 g, 25.3 mmol in toluene (50 mL) and IPA (50 mL) was added 5% Pd/C catalyst (type 5R338 from Johnson Matthey Ltd., 59.4% w/w water, 0.265 g, 0.050 mmol), and the mixture thereafter hydrogenated at rt and 1 bar hydrogen for 23 h. The reaction mixture was filtered through Arbocell BC 200™, and the filtrate was evaporated to dryness to yield Compound (I). Compound (I) was dissolved in IPA (30 mL) and toluene (70 mL), and aq. HCl (2.7 mL, 32.8 mmol, 37% w/w) was added dropwise at rt with vigorous stirring. Then more toluene (100 mL) was added and the mixture was concentrated to approx. 50% of the original volume. The formed suspension was filtered, and the precipitate was washed with toluene, and dried in vacuum at 40° C. to yield Compound (I) as HCl-salt (1:1) (9.59 g, 87%) as a solid, with 94% UV purity in LC-MS analysis.
Example 6: Synthesis of Compound (I) as HCl-Salt from Compound (III) and (IV)
[0130] A mixture of Compound (III) (11.0 g, 62 mmol) and Compound (IV) (14.4 g, 59 mmol) was heated in toluene (120 mL) and isopropanol (96 mL) at 75° C. for 3 h. The mixture was allowed to cool to room temperature, and 3% Pt/C (type Noblyst P8080 from Evonik, 61.2% w/w water, 3.06 g, 0.183 mmol) was added. The mixture was hydrogenated at 70-75° C. and 5 bar for 6 h. The reaction mixture was cooled, filtered and the filtrate was evaporated to dryness to yield crude Compound (I) (25.7 g). The crude Compound (I) (24.7 g used, 1 g kept for analysis) was dissolved in toluene (205 mL) at rt and the organic layer was washed twice with a 2% sodium hydroxide solution (79 mL), followed by washing with a mixture of 3% solution of ammonium chloride (74 mL) and water (74 mL). A solution of diluted hydrochloric acid (prepared from 6.4 mL 37% w/w aq. HCl and 21.3 mL water) was added over a period of 10 min. Acetonitrile (20 mL) was added and the mixture was heated to 50° C. Upon cooling to 30° C. Compound (I) as HCl-salt (1:1) precipitated, and it was isolated by filtration at rt, and washed with a mixture of toluene/acetonitrile, dilute HCl and water. The wet product was dried at 65° C. under vacuum overnight providing dry Compound (I) as HCl salt (1:1) (20.4 g, 47 mmol, 83% yield corrected for 1 g sample taken), with 99.1% UV purity in HPLC analysis.
Example 7: Reprecipitation of Compound (I) as HCl-Salt (1:1)
[0131] A suspension of Compound (I) as HCl salt (1:1) (20.0 g, 99.1% UV purity in HPLC analysis) in toluene (160 mL) and acetonitrile (60 mL) was heated to 73° C. to obtain dissolution and then cooled to 51° C., seeded with Compound(I) as HCl salt (1:1) (100 mg), and further cooled to 20° C. The formed suspension was filtered, and the filter cake was washed with a mixture of toluene/acetonitrile. The wet product was dried at 65° C. under vacuum providing dry Compound (I) as HCl-salt (1:1) (17.5 g, 88%), with 99.7% UV purity in HPLC analysis. | The present invention relates to the preparation of N-(2-(6-fluoro-1H-indol-3-yl)-ethyl)-3-(2,2,3,3-tetrafluoropropoxy)-benzylamine (Compound I), INN-name idalopirdine, and pharmaceutically acceptable salts thereof: | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application contains subject matter, which is related to the subject matter of the following co-pending applications, each of which is assigned to the same assignee as this application, International Business Machines Corporation of Armonk, N.Y. Each of the below listed applications is hereby incorporated herein by reference in its entirety:
Ser. No. 11/620,297 entitled ‘Hierarchical Six-Transistor SRAM’;
Ser. No. 11/620,282 entitled ‘Hierarchical 2T-DRAM with Self-Timed Sensing’;
Ser. No. 11/620,328 entitled ‘eDRAM Hierarchical Differential Sense AMP’; and
Ser. No. 11/108,369 entitled ‘DRAM Hierarchical Data Path’.
TRADEMARKS
IBM® is a registered trademark of International Business Machines Corporation, Armonk, N.Y., U.S.A. Other names used herein may be registered trademarks, trademarks or product names of International Business Machines Corporation or other companies.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an SRAM memory array comprising memory cells with each cell containing seven devices, and in particular to a memory array wherein the basic storage nodes, which store the true and complement of the data, are constructed from six devices, forming a cross-coupled flip-flop cell. One internal storage node of this cell being connected to a separate read-pass device which passes the state of this node to a local bit line (LBL) for single-ended sensing, with the gate of this separate read-pass device connected to a separate read-word line.
2. Description of Background
Before our invention current six device SRAM cells were encountering significant stability problems as we scale below 0.1 micron. The main reason for this is that the device tolerances, particularly the threshold voltage variations from device to device, do not scale appropriately as the technology scales to smaller dimensions. When an SRAM cell is read, the bit lines are precharged ‘HIGH’ which places a ‘disturb’ signal on the ‘0’ node of the cross-coupled flip-flop. For the nominal design case, this ‘disturb’ signal is quite tolerable. However, if the threshold variations between devices is sufficiently large, this ‘disturb’ signal can cause some cells to flip state, i.e. a stored ‘0’ becomes a ‘1’ and vice versa. Current SRAM cell designs employ two techniques to circumvent this, 1) reduce threshold variations by making the devices, and hence cell, larger than the smallest size normal scaling rules would allow, and 2) use eight devices per cell, with the extra devices eliminating the ‘disturb’ signal during reading. Both techniques significantly increase the size of the SRAM cell and hence reduce the density, a very undesirable result.
A typical, 6T SRAM cell has two internal nodes, ‘A’ and ‘B’ one example of which is illustrated in prior art FIG. 1A which store ‘0’/‘1’ respectively on the two nodes for a stored ‘0’, and the reverse of ‘1’/‘0’ respectively on the nodes for a stored ‘1’. These two nodes are coupled to a pair of balanced bit/sense lines, which are used for both reading and writing. For reading the state of the cell, both bit lines are precharged ‘HIGH’ through a pass access device on each node (not shown). Subsequently, the word line of the selected row goes ‘HIGH’ and connects nodes ‘A’ and ‘B’ of this cell to the precharged bit lines through devices N 2 and N 3 . As a result, within the cell, the internal storage node, which happens to currently be latched at ‘0’, will thus see a large voltage applied to it, which is the ‘disturb’ signal. If the difference in threshold voltages of the cross-coupled devices N 1 and N 2 is sufficiently large, this ‘disturb’ can cause the voltage on this ‘0’ node to rise sufficiently such that the cross-coupled arrangement will pull the previously ‘1’ node to ‘0’, thus reversing the stored state, a significant error.
One current method used to eliminate this read ‘disturb’ sensitivity is the use of an eight device SRAM cell one example of which is illustrated in prior art FIG. 1B . This adds two nFET devices, plus one read bit line and one read word line to each cell as illustrated by the encircled area 102 . One of the storage nodes, for example node ‘B’ as illustrated, is connected to the gate of the pull down nFET device. This device has its source grounded and its drain in series with the read-select nFET. This read-select device has its drain tied to a separate read-bit line, while a separate read word line activates its gate. Thus each cell has the addition of two FET devices, plus one read bit line and one read word line.
For a given technology, the threshold variations between adjacent devices become larger as the devices approach minimum dimensions. Thus one method for improving stability is by making the device channel length and width larger, which results in lower density, an undesirable effect. If we wish to increase cell stability without increasing the cell device sizes, the bit line capacitance must be reduced without significantly increasing the effective, average cell size.
SUMMARY OF THE INVENTION
The shortcomings of the prior art are overcome and additional advantages are provided through the provision of an SRAM memory array comprising a plurality of memory cells, each of the plurality of memory cells further comprising a device, each of the plurality of memory cells having seven of the device; a first storage node; a second storage node; and a first local bit line; the first storage node and the second storage node store true and complement of data and are constructed with six of the devices forming a cross-coupled flip-flop cell, one of the devices being configured as a first read-pass device, the second storage node is connected to the first read-pass device, the first read-pass device passes the state of the second storage node to the first local bit line effectuating single ended sensing, the first read-pass device gate is connected to a first read word line.
System and computer program products corresponding to the above-summarized methods are also described and claimed herein.
Additional features and advantages are realized through the techniques of the present invention. Other embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed invention. For a better understanding of the invention with advantages and features, refer to the description and to the drawings.
TECHNICAL EFFECTS
As a result of the summarized invention, technically we have achieved a solution which is an SRAM memory array comprising memory cells with each cell containing seven devices coupled with a hierarchical bit/sense line structure (7 Transistor/Hierarchical cell, 7T/H) to significantly reduce the read ‘disturb’ sensitivity associated with a smaller cell size.
BRIEF DESCRIPTION OF THE DRAWINGS
The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other objects, features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
FIG. 1A illustrates one example of a prior art six device (6T) SRAM cell having two internal nodes, ‘A’ and ‘B’;
FIG. 1B illustrates one example of a prior art eight device (8T) SRAM cell which uses two additional devices for the reading of the cross-coupled six device SRAM cell;
FIG. 1C illustrates one example of a prior art read ‘disturb’ voltage on node ‘B’ of 6T cell due to the discharging of a very large, precharged bit line capacitance through device N 0 ;
FIG. 2 illustrates one example of a modified SRAM cell showing addition of one read-pass n-device per cell, connected to local read bit line LRBL for isolating the read ‘disturb’. Single-ended sensing is used via a hierarchical bit line pair, LRBL and global read bit line GRBL, interconnected by one read-head for every 8 or more (a design parameter) cells per LRBL;
FIG. 3 illustrates one example of a cell showing multiple cells, connected to one complete local read bit line, LRBL for isolating the read ‘disturb’ issue. Single-ended sensing is used via a hierarchical bit line pair, LRBL and global read bit line GRBL, interconnected by one read-head for every, typically, 8 or more (a design parameter) cells per LRBL. (16 chosen for simplicity);
FIG. 4 illustrates one example of a multiple local read bit lines LRBLs connected to multiple global read bit line, GRBL with column read-sense amp at end of the GRBL;
FIG. 5 illustrates one example of a modified, symmetrical 7T/H SRAM cell, providing three separate ports, one separate port for writing and two separate ports for two simultaneous reads of different cells. All three ports can reference same or different cells simultaneously;
FIG. 6 illustrates one example of simulation results for 7T/H SRAM of FIG. 2 write-bit line all have 256 cells;
FIG. 7 illustrates one example of simulation results for 8T SRAM of prior art FIG. 1B write-bit line and read-bit line have same number of cells; and
FIG. 8A-8B illustrates one example of Vt-Tolerance—stability of 7T/H SRAM of FIG. 2 to device Vt differences. Write-bit lines all have 256 cells.
The detailed description explains the preferred embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
DETAILED DESCRIPTION OF THE INVENTION
Turning now to the drawings in greater detail, in an exemplary embodiment of the present invention, this invention makes use of a seven device SRAM cell coupled with a hierarchical bit/sense line structure (7 Transistor/Hierarchical cell, 7T/H) to significantly reduce the read ‘disturb’ sensitivity with a smaller cell size and hence minimal impact on density. It also provides a faster read access for comparable loads on the read bit line. Write time may also be slightly reduced due to the smaller cell size, depending on the technology layout restrictions.
In an exemplary embodiment of the present invention, the ‘disturb’ signal on the internal node is significantly reduced by the use of only one additional pass gate tied to one of the internal node (either ‘A’ or ‘B’) and the pass gate is connected to a local read bit line, LRBL, which is one section of a hierarchical bit line structure one example of which is illustrated in FIG. 2 . The circuit 106 encircled is added to each 6T cell. Several cells, such as 8 to 64, depending on the desired speed and other specs, share the local read bit line, LRBL. In the following, 16 bits per LRBL are assumed, to simplify the figures. The local read bit line, LRBL, connected to 16 pass gates from 16 cells, has one read-head device with its source tied to ground, drain tied to a global read bit line, GRBL, and gate connected to the LRBL as illustrated, (for an nFET read-head—a pFET device can also be used for a read-head but is not as effective). Multiple local read bit lines, LRBLs, each with a separate read-head, are connected to a global read bit line as discussed latter.
In addition to the read-head, each LRBL has a separate nFET for discharging and holding LRBL to ground after sensing as indicated by device “LRBL Precharge 0” in FIG. 3 . This is required since once an LRBL is charged high, by reading a stored ‘1’ for instance, the read-head will be turned ‘ON’ and remain ‘ON’. If the LRBL is not discharged, subsequent attempts to read other cells which have a stored ‘0’ on the same LRBL will encounter a large voltage already on the LRBL and will possibly give an incorrect sense signal.
Thus one advantage of the present invention is that the SRAM read ‘disturb’ can be significantly reduced by the addition of only one read-pass nFET per cell plus one read-head and one LRBL Precharge-‘0’ device per every 8 to 64 cells (depending of design parameters) as illustrated by the encircled circuit 104 . The two additional bit lines per cell, namely LRBL and GRBL, run parallel to each other and can be placed on different metal levels to minimize the impact on cell area. This is a substantial area saving and allows a faster read cycle; the amount depending on how much of a density improvement is desired.
One of the issues that can give rise to the read ‘disturb’ can best be understood in terms of the capacitance loading connected to an SRAM cell during reading. An equivalent circuit for the reading of the cross-coupled six device SRAM cell, is illustrated in prior art FIG. 1C . It is assumed that the storage node ‘B’ is at ‘0’ volts initially (node ‘A’ necessarily at Vdd volts). In the state of the art, balanced sensing, a pair of (nearly) identical capacitors, C(BL) (capacitance of the bit lines) are precharged to Vdd and then suddenly connected to nodes ‘A’ and ‘B’. Node ‘A’, being already at Vdd, is not affected. However, node ‘B’, initially at ‘0’, now has a large capacitor, C(BL) the bit line capacitance at voltage Vdd connected to it. The FET pull-down device, N 0 , must sink the charge on C(BL) to ground in order to discharge it to some low value. However, device N 0 , even in the ‘ON’ state has a significant resistance, so the voltage from node ‘B’ to ground will increase above ‘0’. In the meantime, device N 1 has its gate voltage supposedly at ‘0’ (at voltage of node ‘B’) so it is ‘OFF’, and P 1 is ‘ON’, which allows node ‘A’ to remain ‘HIGH’. However, if the threshold voltage, Vt, of device N 1 just happens to be sufficiently lower than that of device N 0 , and if node ‘B’ happens to rise sufficiently ‘HIGH’, device N 1 will start to turn ‘ON’. The feedback effect of the cross-coupled arrangement will reinforce this and can cause the node voltages at ‘A’ and ‘B’ to reverse states, an error.
The culprit in this scenario is the very large bit line capacitance which makes it difficult to hold node ‘B’ at ‘0’, plus the large tolerance variation between devices N 0 and N 1 (note, tolerance variations on P 1 and P 0 contribute in a somewhat analogous manner).
Since the tolerance variations on the FET devices are fixed by the technology, these cannot be changed, except by making the devices and thus cell larger than minimum size. The tolerance difference between adjacent devices varies as k/(SqRt(Width*Length)) where ‘k’ is a technology constant. Thus, if the length and/or width are made larger, the tolerance variation is reduced, but the density decreases significantly, if this is to be avoided, then the alternative solution is to control the capacitance load connected to the internal nodes, for reading the cell state. This is exactly what differentiates the 7T/H from the 8T cell. In the 8T cell (prior art FIG. 1B ) the large bit line capacitance C(BL) of the 6T cell is replaced by a very small capacitor, namely the gate capacitance of the pull-down FET which is directly connected to node ‘B’. Also, this gate capacitance is not precharged into any state, but rather takes on the voltage of node ‘B’ during writing of the cell. There are some other capacitance components, and displacement currents when the read-select device is turned ‘ON’ for reading that cell, but these are small. Thus we expect this arrangement to have a minimum ‘disturb’ effect on the cell. However, it requires two additional devices per cell, giving a significant reduction in density.
Compared to the 6T cell, the 7T/H cell of this invention significantly reduces the capacitance load, C(BL) placed on the cell during reading by the use of a hierarchical bit line. Thus the 7T/H cell will tolerate larger ‘disturb’ conditions than the 6T cell, for equivalent number of cells per bit line. The 7T/H cell will be slightly less stable than the 8T cell. Nevertheless there is a very wide range of stable cell operation for the 7T/H cell and it gives significantly faster read-access time and smaller cell size than the 8T cell.
The writing of the 7T/H cell is identical to that of the 6T or 8T cell. The writing speed will be comparable or slightly faster than the 8T cell due to the density improvement, (shorter word line and/or bit line, depending on layout).
Multiple cells connected to one global read bit line referred to as a column are connected by means of a hierarchy of local read bit lines, LRBLs, and read-heads, RH, as indicated in FIG. 3 . Multiple cells are connected to any one LRBL, through multiple read-pass nFETs, one for each cell as shown. Multiple such LRBLs are connected to a GRBL via a read-head, one read-head per LRBL. The number of LRBLs with read-head, per GRBL is a design parameter. A typical number might be 16, with a range from 1 to 64 or more. This column arrangement gives one bit per word line. To achieve multiple bits per word line, identical columns are added to the word lines as one example is illustrated in FIG. 4 .
It can be seen that for both the 8T and 7T cells, an additional word line is required. Furthermore, for the 8T cell, one additional bit line is required and the 7T cell requires two additional bit lines, namely the LRBL (short segments) and GRBL. However, these two bits lines run parallel to each other and can be placed on separate metal wiring levels, requiring only one wiring pitch per cell, similar to the 8T cell.
For reading, the 7T/H cell makes use of a hierarchical bit line structure to achieve speed and density. A global read bit line, GRBL, is initially precharged high (e.g. to Vdd) and subsequently is either pulled to ‘0’ or remains ‘HIGH’ for sensing the two binary states of the cell. Whether the GRBL is pulled to ‘0’ for a stored ‘1’ or stored ‘0’ is purely arbitrary, depending on the definition of internal cell nodes, ‘A’ and ‘B’ illustrated in FIG. 2 , for ‘1’ and ‘0’, as well as which of these two node is used for reading, as will be seen.
In an exemplary embodiment for example and not a limitation, the fundamental idea for reading is that one of the cell nodes, ‘A’ or ‘B’, (assume node ‘B’ in the following) is initially connected to a very lightly loaded (small capacitance) local read bit line, LRBL, through a read select pass gate as illustrated in FIG. 2 . This pass device transfers the voltage at node ‘B’ to the gate of a read-head, RH, which is connected to the global read bit line as illustrated. GRBL has previously been precharged ‘HIGH’, to Vdd. If node ‘B’ is at Vdd (node ‘A’ thus is at ‘0’), the read-head device will be turned ‘ON’ and will discharge GRBL to ‘0’. If node ‘B’ is at ‘0’ (node ‘A’ high), then the RH device is ‘OFF’ and the GRBL remains ‘HIGH’.
Before reading commences the local read bit line, LRBL, is discharged and held at ground. At the beginning of the read cycle, the LRBL is released from ground (floating) by turning ‘OFF’ the nFET LRBL precharge ‘0’. This is necessary since an array of cells will have multiple LRBL and multiple read-heads connected to one global read bit line, and all these other LRBL must be deactivated (at ‘0’) so their respective read-heads are ‘OFF’, except the one chosen to be read. By so doing, the selected LRBL can take on the voltage state of node ‘B’ of the selected cell when the read-pass device is turned ‘ON’ by a +voltage signal on a separate word line used for reading, namely word-line-read, WLR.
Simulations have shown that for typical cell device sizes, and lengths of bit lines crossing 256 word lines per column (row any value) the 7T/H sensing structure gives a read time from word line ‘HIGH’ (50% pt) to GRBL ‘LOW’ (50% Pt) which is more than twice as fast as the 8T structure. Presently, SRAM arrays for high speed L2 cache applications are using very short bit lines, i.e. column covering only 8 to 16 bits, in order to limit the ‘C’ loading, thus giving higher speed and better stability. However, this requires significantly more peripheral devices (sense amps, drivers, selectors etc), which can be avoided by the use of the 7T/H cell.
On example of simulations of the 7T/H and 8Tcells for various configurations and conditions are illustrated in FIGS. 6 and 7 . Referring to FIGS. 6 and 7 there is illustrated one example of tables that present the nominal read access delay for the 7T/H and 8T cell respectively and show very significant speed improvement of the 7T/H over the 8T cell, as follows for three different column heights covering 64, 128 and 256 word lines (64, 128, 256 cells per bit line) the array delay (50% points) from word line rising to bit line falling for the 7T/H vs. 8T cell using a nominal design with near minimum devices three cases of which are summarized as follows:
Case 1 :
64 bits per global bit line
Delay 7T/H=68 ps
Delay 8T=122 ps
Case 2 :
128 bits per global bit line
Delay 7T/H=96 ps
Delay 8T=234 ps
Case 3 :
256 bits per global bit line
Delay 7T/H=168 ps
Delay 8T=444 ps
In each case, the 7T/H cell is a factor of almost 2 to 2.6 times faster than the 8T cell. The complete set of devices and conditions for these simulations are illustrated in FIG. 6 , and 7 . It can be seen that increasing the sizes of some selected devices can improve the speed of these cells, but this compromises density. Thus various density speed tradeoffs are possible.
One of the fundamental design issues can be when a read cycle commences and the capacitance load of the selected LRBL and associated devices is ‘dumped’ on node ‘B’ of the SRAM cell ( FIG. 2 ). The current drawn out of node ‘B’ to charge this LRBL is proportional to ‘C’ dV/dt where ‘C’ is the total capacitance connected to node ‘B’ by the read-pass device, and ‘V’ is the voltage across the LRBL capacitance. The faster this occurs (i.e. shorter time constant on the RC read circuit), the more current drawn from node ‘B’, and the larger the ‘disturb’ on node ‘B’. The cell may or may not be able to supply this charging current in a stable manner, depending on the actual, and relative sizes of the various devices. For increased speed, a fast charging time (small time constant) is desired which reduces the ‘disturb’ margins on the SRAM cell Vt tolerances (i.e. more sensitive to ‘disturbs’). The read stability can be improved by making the time constant larger—one way to do this is by decreasing the width of the read-pass device. This will make the cell smaller, which is desirable, but slower, usually not desirable, but depends on the application.
In a similar manner, the cell stability for reading can be adjusted by changing (very slightly) the widths of devices in the cell itself. For instance, if the number of cells connected to one LRBL is increased, the ‘C’ load on node ‘B’ increases and may cause instability. This can be improved by a slight increase in the width of the cell P 0 device as illustrated in FIG. 2 . The tradeoffs are very dependent on exact array and cell parameters, but many such tradeoffs are possible and give this cell a wide design range of density/speed.
The 7T/H cell and array is quite stable over a wide range of Vt variations. For the devices sizes used in the cell, a typical maximum spread in Vt (in current technologies) for near-adjacent devices is a delta of about 50 mV. Assuming this is divided as plus and minus 25 mV for adjacent n devices and likewise for adjacent p devices, and picking the worst case arrangement of the Vt variations in the cross-coupled flip-flop, the stability for the 7T/H cell in various configurations (number of cells on Local Bit Line, LBL, and number of LBL on a global read bit line, GRBL) one example of which is illustrated in FIGS. 8A-8B (Vt-Tolerances). It can be seen that the cell, in a minimum configuration, is stable for up to 4 times (+ and −100 mV) the allowed Vt spread on the cell devices. The cell is also very tolerant of Vt variations in the read-head, an important issue.
The 7T/H cell may possibly even offer advantages over the 6T cell. As the device tolerances become more severe, the 6T cell must use device sizes, which are larger than, normal scaling would allow. In such cases, the 7T/H cell can use smaller devices, and even though an additional device is required per cell, the total area, even including the additional read and write lines, may give a better density. The design point where this would happen is highly technology dependent, but could possibly be significant.
There are many tradeoffs, which can be made for speed vs. cell size which give this 7T/H cell considerable flexibility and potential application.
By making the 7T/H SRAM cell symmetrical, one example of which is illustrated in FIG. 5 , several additional and important features are achieved. If the additional global read bit line, GRBL 2 and read word line 2 are keep separate from GRBL 1 and read word line 1 , then the cell becomes a true 3-port cell capable of simultaneously writing to one cell while reading data from two other cells. These simultaneous three accesses can be directed all to the same cell, to two cells or three cells with no interference.
Alternatively, if the read word line 2 is electrically tied to read word line 1 , then only one cell can be read on one cycle (another can be simultaneously written, of course). But now the bit read lines, GRBL 1 and GRBL 2 act as a balance sense pair which gives a signal transition and hence clock for reading both a stored ‘1’ and ‘0’, unlike the previous, single ended sensing. This has some advantages in overall clocking and timing of full arrays.
The capabilities of the present invention can be implemented in software, firmware, hardware or some combination thereof.
As one example, one or more aspects of the present invention can be included in an article of manufacture (e.g., one or more computer program products) having, for instance, computer usable media. The media has embodied therein, for instance, computer readable program code means for providing and facilitating the capabilities of the present invention. The article of manufacture can be included as a part of a computer system or sold separately.
Additionally, at least one program storage device readable by a machine, tangibly embodying at least one program of instructions executable by the machine to perform the capabilities of the present invention can be provided.
The flow diagrams depicted herein are just examples. There may be many variations to these diagrams or the steps (or operations) described therein without departing from the spirit of the invention. For instance, the steps may be performed in a differing order, or steps may be added, deleted or modified. All of these variations are considered a part of the claimed invention.
While the preferred embodiment to the invention has been described, it will be understood that those skilled in the art, both now and in the future, may make various improvements and enhancements which fall within the scope of the claims which follow. These claims should be construed to maintain the proper protection for the invention first described. | An embodiment of the present invention is an SRAM memory array comprising memory cells with each cell containing seven devices, wherein the basic storage nodes, which store the true and complement of the data, are constructed from six devices, forming a cross-coupled flip-flop cell. One internal storage node of this cell being connected to a separate read-pass device which passes the state of this node to a local bit line (LBL) for single-ended sensing, with the gate of this separate read-pass device connected to a separate read-word line. | 6 |
BACKGROUND AND SUMMARY OF THE INVENTION
[0001] This invention relates to a working cylinder having a working chamber defined by a cylinder barrel, at least one of the end sections and a piston, at least one supply port for the working medium for this working chamber, an exhaust port for the working medium from this working chamber, a valve, specifically for controlling this type of working cylinder; at least one inlet and one outlet for a work medium; at least one control port or a switch valve, specifically for controlling a double-action working cylinder; at least one connector and at least two outlets for a working medium; at least one control port; a working unit, including at least one compression source for the working medium; at least one and at the most a double-action working cylinder; at least one valve for controllable supply of the working cylinder with a working medium; and at least one line for the working medium from the valve to the working cylinder.
[0002] Multiple functions are necessary for the conversion of pneumatic energy to mechanical power, for example, whereby these functions are performed by various components, elements or group of components of the pneumatic working units in this case. Thereby the signal to move forward is converted into an air pressure signal of the corresponding working chamber in the working cylinder and possibly convert it to a depressurizing signal of the opposed chamber or these signals are to be combined. This is accomplished in traditional designs by a valve, which also takes care of conversion of the compressed air network in the corresponding working chamber, opening of the opposed chamber to depressurize the cylinder, and discharge of the outgoing air into the atmosphere. The line as well as the compressed air network to the cylinder are pneumatic lines, which only take care of the conversion of air pressure to mechanical power through the cylinder piston and the discharge of air from the cylinder into the atmosphere. Up to now, pneumatic cylinders were pressurized and depressurized through the same lines even though these two functions required different diameters. Valves use up to now for the control of double-action pneumatic cylinders had to be designed large in size because their function and the diversion of the pressure medium into the corresponding cylinder chamber and also because of the depressurization control of each opposed chamber whereby a large amount of space remained unused at the end sections of the pneumatic cylinders. The situation was similar for hydraulic units.
[0003] The object of the present invention is therefore to create elements for a pressure-actuated working unit and to create an improved working unit of this type in itself, whereby a smaller size in design of at least the valve is obtained, the already existing space in the cylinder is better utilized and the output capacity of the individual elements is adjusted better and more efficiently.
[0004] This object is reached primarily with a working cylinder of the above-mentioned type, according to the invention, in that the cylinder exhaust port has a valve, which may be regulated by the pressure of the working medium at the supply port. Thereby, for example, a component group for a function of the pressure-actuated pneumatic working unit is moved from the valve into the working cylinder, preferably into its end section, where there is already sufficient space for the corresponding component without the need for larger dimensions. Therefore, the valve itself may be made smaller because of the elimination of components necessary for discharge or depressurization control.
[0005] Further improved space utilization is accomplished, according to an advantageous embodiment, in that the supply port and the exhaust port are directly connected to one another by a passageway for the working medium, whereby the valve is installed inside this passageway.
[0006] Optimal space utilization within the working cylinder is possible if a supply channel to the work area leads from the supply port for the working medium, parallel to the passageway, and subsequently to the exhaust port.
[0007] In order to satisfy the different requirements for pressurizing and depressurizing or for supplying and discharging of the working medium, it is advantageously planned that the supply channel has a smaller diameter than the passageway to the exhaust port. Now the pressurizing or supplying of the working medium may be accomplished in a simple way without additional structural efforts by better using the smaller diameter channel and by using the optimal larger diameter channel for depressurizing the working cylinder or for discharging the working medium.
[0008] Requirements may be solved in an advantageous manner and in a simple design concerning noise protection in case of pneumatic systems or concerning the flow phenomenon in case of hydraulic systems, by topping the exhaust port with a speed throttle element and/or a muffler.
[0009] According to an advantageous embodiment of the invention, the valve has in its design a sealing element that moves freely and covers the passageway and which also covers the supply channel at least partly.
[0010] Thereby there has been realized, in a simple and very functional manner, the above-mentioned control for depressurizing dependent on pressurizing or discharge of the working medium dependent on applying pressure to the working chamber of the cylinder.
[0011] The innovative construction of the working cylinder is especially advantageous if it is designed as a double-action cylinder and if it is preferably made at each side as shown in the above-mentioned paragraph and by being the same at both sides, at least functionally, thereby the mentioned advantages are twice as much, meaning advantages for both sides are taken into consideration.
[0012] The first-mentioned valve, which is particularly meant to be used for the control of the innovative pneumatic working cylinder, is identified according to an additional characteristic of the invention by an exhaust channel for the working medium, originating from a location between the throttle element of the valve and at least one outlet, whereby there is located an adjustable discharge or depressurizing valve within this exhaust channel, which may be adjusted by the pressure that is applied at the control port. This channel may be placed within the valve housing itself or in one of the elements within the valve and this causes thereby no increase in its dimensions. The valve must therefore be only large enough to contain the absolutely necessary connections and control elements so that optimal functioning is reached with the smallest structural dimension.
[0013] As firstly described, there is a switch valve designed for the double-action working cylinder, characterized by at least one exhaust channel for each cylinder located between the valve element and each outlet, whereby there is located in each exhaust channel at least one adjustable discharge or exhaust control valve that has pressure applied at the control port. Thereby, the same advantages have been reached as mentioned for the previous arrangement, whereby the air net connection or the connection for the source of the pressure medium must be connected alternately to one of the two working cylinders. The same is true, in principle, for an electric adjustable discharge or exhaust valve.
[0014] According to an especially advantageous embodiment, there is a switch valve designed as a rocker valve, which has a switchable rocker seal element between two switching positions that has pressure applied to the control connection so that the discharge or exhaust control valve remains in an effective connection with the control area through at least one device for transferring the pressure that is applied to the control port. With this type of design there is guaranteed an immediate safe and rapid depressurizing control or control for exhaust of the pressure medium from the working cylinder by having the smallest wasted space, allowing rapid switching even with large port diameters, and keeping a tight seal. Based on the small pivoting movement of the rocker, which is sufficient for the switching action, the innovative valve may be built in a very small and flat shape and may be built in layered sections that allow easy operating, easy repair and assembly. With the innovative design of the switch valve, a smaller size in construction has been reached as compared even with two rocker valves for a 5/2-way function.
[0015] A flexible membrane is advantageously planned that is a part of the wall in the control area and which serves as a device for transferring pressure to actuate the actual sealing element through a valve shaft. This sealing element thereby blocks or opens the discharge channel. This ensures a very good switching capability of the discharge or exhaust valve in a structural simple and space-saving manner.
[0016] As a matter of course, the above mentioned advantages may be doubled by optimal utilization of the existing spaces, which applies to both sides for which control is necessary and where the switch valve has at least the same functional design at both sides.
[0017] The innovative pneumatic working unit includes at least one pressure source for the working medium, at least one pneumatic working cylinder, at least one valve for the controllable supply of the working cylinder with a working medium, at least one line for the working medium from the valve to the working cylinder. It is characterized by better space utilization and downsizing or decreasing of components as well as better power adjustment of the elements. It is also characterized in that there is only one line to the cylinder per cylinder working chamber carrying the working medium, the lines may be depressurized or the pressure may be reduced by the use of at least one switchable discharge or exhaust valve, the working cylinder is designed according to at least one of the above-mentioned paragraphs and whereby its exhaust port is kept open.
[0018] It is planned, for example, that pressure be applied to the control port of the discharge or exhaust valve to reach the best possible and structural most simple combination of pressurizing and depressurizing function or supplying and discharging of the working medium.
[0019] In a preferred way, and to reach the above-mentioned advantages, the working unit is characterized by a valve arrangement which has a exhaust channel for the working medium that originates at a location between the shut-off element of the valve and at least one outlet and whereby there is located in this exhaust channel a discharge or exhaust valve that is controlled by the pressure applied at the control port.
[0020] The pneumatic working unit, which has at least one double-action pneumatic working cylinder, is characterized according to one advantageous version in that there is one line per working cylinder carrying the working medium, that the working cylinder corresponds to at least one of the related paragraphs, and that one switch-valve arrangement corresponds to at least one of the above related paragraphs.
[0021] According to an additional invention characteristic, there is a control logic arrangement, which has connectors for communication (preferably a field bus), electrical control and supply for the working medium. Thereby a more compact size of the working unit is possible even at increased versatility.
[0022] According to another characteristic of the invention, the valve to control one or both working chambers of the working cylinder may of course be directly attached to it or integrated within, preferably in one of the end sections of the cylinder.
[0023] One or each exhaust control valve may also be advantageously attached to the working cylinder or the switch valve or may be structural integrated within. In both cases, there is far reaching simplification in assembly and arrangement at the assembly point. Furthermore, lines may be eliminated between these assembled components and in case of structural integration, connections and sealing areas may also be eliminated, whereby, on the one hand, the arrangement of the entire system is greatly simplified and, on the other hand, its operational dependability may be increased considerably based on less danger of leakage. The just-mentioned possibilities may also be applied advantageously in the design of the switch valve in its rocker type construction.
[0024] Some design examples of pneumatic versions are explained in more detail in the subsequent description as they relate to the attached drawings, whereby these examples are not to be evaluated in any way as limitations to the general innovative idea encompassed by the accompanying claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] [0025]FIG. 1 shows a sectional view of a preferred embodiment of the inventive working cylinder.
[0026] [0026]FIG. 2 is a partial, cross-sectional illustration of an inventive switch valve with integrated exhaust control valves.
[0027] [0027]FIG. 3 shows a possible version of the exhaust control valves integrated within the switch valve.
[0028] [0028]FIG. 4 and FIG. 5 are schematic connection diagrams of inventive pneumatic working units.
[0029] [0029]FIG. 6 illustrates a switch valve of a rocker-valve design with corresponding exhaust control valves.
[0030] [0030]FIG. 7 shows a switch valve of the rocker-valve design that has integrated exhaust control valves.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] The pneumatic working cylinder A illustrated in FIG. 1, actuated preferably by compressed air as a working medium, consists of a cylinder barrel 1 , which ends are closed off with a rear cover 2 and a front cover 3 . A movable piston 4 is placed into this working cylinder A. The piston transfers the mechanical force onto the element to be powered through a piston rod 5 , which runs through the front cover 3 while maintaining a seal. The invention may of course also be applied in the same manner to cylinders without piston rods and working mediums other than compressed air, for example: hydraulic working mediums.
[0032] The first working chamber 6 is defined between the rear cover 2 and the piston 4 of the illustrated double-action working cylinder A and the second working chamber 7 is defined between the front cover 3 and the piston 4 , whereby according to the supply of working medium and depressurization, the working chamber in the movement of the piston 4 represents a depressurized opposed chamber in relation to the pressurized temporary working chamber. The compressed air is moved to the working chamber through the ports 8 a and 8 b , which are placed in the supply ports 9 a and 9 b , whereby the compressed air flows into the working chambers 6 and 7 through the supply channels 10 a and 10 b , which have a relative small diameter. Parallel to these supply channels 10 a and 10 b , passageways 11 a , 11 b lead away from each of the supply ports 9 a , 9 b , and these passageways lead to two exhaust ports 12 a , 12 b for the air from the working chambers 6 , 7 . No lines are connected to these exhaust ports 12 a , 12 b , since they lead directly or preferably through a muffler or a speed regulating throttle with an attached muffler (both vaguely illustrated) into the open atmosphere.
[0033] The mouth of the passageway 11 a , 11 b , which is located in the supply port 9 a , 9 b , forms a valve seat for a preferably flat valve element 13 a , 13 b , which is also located in the supply port 9 a , 9 b , and this valve element covers the mouth completely and also covers, at least partly, the mouth of the parallel running supply channel 10 a , 10 b that leads to the working chamber 6 or 7 . Whenever, for example, compressed air is moved into the working chamber 6 through the corresponding port 8 a (located in the drawing to the right), then the right valve element 13 a is pushed against its seat and seals subsequently the passageway 11 a to the right exhaust port 12 a . The compressed air flows past the valve element 13 a into the supply channel 10 a and continues to flow into the working chamber 6 . Thereby the piston 4 is pushed in sequence to the left and the piston rod 5 moves outward. If the left port is now without pressure, caused by the exhaust valve, then this piston movement can lift the left valve element 13 b from its valve seat in the opposed chamber shown as working chamber 7 , whereby the passageway 11 b is opened up and the air from the opposed chamber may now flow through the exhaust port 12 b into the atmosphere.
[0034] In reverse, as soon as the right port 8 a is without pressure and the left port 8 b is supplied with compressed air, then the conditions are reversed and the left valve element 13 b seals off the passageway 11 b so that the compressed air is only forwarded into the working chamber 7 . At the opposite side, the air that had been pushed back is now pushing from the opposed chamber 6 and lifts the valve element 13 a . As soon as the port 8 a is without pressure, then the air is able to escape through the passageway 11 a and the exhaust port 12 a . Other valve designs might make sense and might be necessary for liquid working mediums, which however does not change the principle of the invention or its functioning.
[0035] With the use of this type of working cylinder A, which has integrated pressure release or exhaust, the exhaust valve arrangement may be avoided, as shown in the version in FIG. 2 , for example, and the component may be reduced in size correspondingly. The actual valve element 15 is placed movable within the housing 14 of the valve V, whereby the valve element 15 connects alternatively the compressed air port 16 with both working ports 17 a and 17 b , which supply with compressed air the work chambers 6 and 7 of the working cylinder. A through pressure lines and connectors 8 a or 8 b . Thereby pressure from the control ports 18 is applied to the valve element 15 .
[0036] A discharge channel 19 may be designed according to a version of the valve to integrate in simple manner the depressurization control function for the pressure lines to the ports 8 a or 8 b at the working cylinder into the valve. This discharge channel 19 may lead from a location between the corresponding outlet 17 a , 17 b of valve V and the actual valve element 15 to a exhaust port 19 a and subsequently into the atmosphere. This discharge channel 19 is closed off by a valve element 20 , as long as the corresponding outlet is connected to the compressed air source. As soon as the control signal switches the direction of movement, as shown in FIG. 3, by applying pressure in the areas 21 through the control pressure, then the valve element 20 is lifted from its seat by the valve piston 22 and thereby opens the connection from the discharge channel 19 through the exhaust port 19 a . The pressure line is thereby depressurized and the valve element 13 a , 13 b , previously under pressure by compressed air, in the working cylinder A is also depressurized and the corresponding working chamber is depressurized as well.
[0037] The above described depressurization function may of course also be actuated by separate exhaust control valves 24 , as it is shown in FIG. 4, whereby the working air line is indicated by solid lines and the control air line is indicated by dotted lines. In the above-shown pneumatic working unit, the compressed air source 25 is connected by a switch valve V to the working cylinder A. The working cylinder A has two integrated depressurization valves 27 a and 27 b , for example, as explained in relation to FIG. 1.
[0038] The control air lines 28 a , 28 b lead to the switch valve V and also to the two depressurization control valves 24 a , 24 b , which block or open the discharge lines in the compressed air lines 29 a and 29 b to the working cylinder A. Whenever, for example, the 9 right control air line 28 a is placed under pressure by the control pressure, then the switch valve V opens the compressed air connection to the right working chamber 6 of the working cylinder A. Since the pre-control pressure is applying force also parallel to the right exhaust valve 24 a , the switch valve is moved at the same time into a position in which the connection of the left compressed air line 29 b opens into the atmosphere and this line is therefore without pressure. Thereby the depressurization valve 27 b is being opened and the left working chamber 7 may be depressurized into the atmosphere. The left exhaust control valve 24 b remains in a closed position since there is no control pressure applied. Instead of two exhaust control valves 24 a and 24 b as shown in FIG. 5, there can also be a single exhaust control valve 30 , whereby both inlets are connected with one of the two pressure lines 29 a and 29 b and whereby its outlet leads into the atmosphere. The exhaust control valve 30 is a traditional 3/2-way valve, for example, the same as the switch valve V. Whenever the left control line 28 b is placed under pressure by the control pressure, the compressed air flows from the compressed air source 25 through the pressure line 29 b to the left working chamber 7 . At the same time, the exhaust control valve is moved into a position by the parallel applied control pressure, in which the right pressure line 29 a is depressurized through the depressurization control valve 30 into the atmosphere and is thereby with out pressure. Now pressure is released at the right exhaust valve 27 a in the working cylinder A and the air may escape from the right working chamber 6 through this valve 27 a and subsequently into the open atmosphere, whereby the right working chamber 6 is now a depressurized opposed chamber.
[0039] An advantageous version of the switch valve is illustrated in FIG. 6. In this version a rocker valve W is planned as a switch valve. An essentially rigid rocker 31 made from metal, for example, moves around a rotational axis and is placed into a valve housing 32 . The rocker 31 is embedded between two elastomer sealing elements 33 —preferably re-enforced by fiber at high pressure—for example, and it rotates around the axis D. The housing 32 has a least one supply connector to the connection with the compressed air source 25 and it has also two working connectors from which the pressure lines 29 a , 29 b lead to the working cylinder A. Whenever a pre-control pressure of any size is applied to the control line 28 a , which applies force onto the left section of the rocker 31 —which force is greater than the supply pressure on P at the right arm of the rocker and the applied force—then the rocker 31 is moved to the position shown in FIG. 6 together with the elastomer sealing elements 33 , which means, a position in which the rocker 31 closes the right valve seat and connects the compressed air source 25 through the left working port to a working chamber of the working cylinder A. The other working port is closed. Since the control line 28 a also applies pressure on the exhaust control valve 24 with the control pressure, the exhaust control valve opens the connection from the right pressure line 29 a into the atmosphere and makes the line thereby pressureless, whereby the right exhaust valve 27 a in the working cylinder also opens and exhausts the corresponding working chamber into the atmosphere. The version of the rocker switch valve W in FIG. 6 or FIG. 7 is advantageous since it is of small structural dimensions and reaches the goal for a pneumatic working unit with the possibly fewest components. In its housing 32 there is installed an insert E with two exhaust valves. The control areas 34 a , 34 b for the actuation of the rocker 31 have a part that is sealed by a flexible membrane 35 and over which membrane 35 the existing pressure in the control room 34 a , 34 b is transferred to the exhaust control valves for actuating their sealing elements 36 a , 36 b , preferably through the valve shafts 37 a , 37 b . From the working connectors to the pressure lines 29 a , 29 b there are discharge channels 38 a , 38 b that lead past the rocker 31 to the exhaust control valves and continue to the exhaust ports out into the atmosphere. The illustrated position of the rocker switch valve W has pressure applied from the control pressure to the left control area 34 b , this control pressure would also apply force through the membrane 35 b and the valve shaft 37 b and would subsequently lift the valve element 36 b of the left depressurization control valve from its valve seat and thereby opens the discharge channel 38 b . The left working port is shut off in this position against the compressed air source 25 ; however, it is exhausted into the atmosphere through the discharge channel 38 b and is made pressureless. The right working port of the pressure line 29 a is connected to the compressed air source 25 and supplies the working chambers of the working cylinder with compressed air. The right exhaust control valve keeps thereby the discharge channel 38 a in a closed position.
[0040] Of course, several or even all mentioned elements of the pressure-actuated working unit may be combined into one single component, whereby great simplification is accomplished for assembly and arrangement at the assembly point. For example, the valve for the control of one or both working chambers or even for double-action working cylinders may have attached a switch valve directly to the working cylinder for the control of both working chambers or the valve may be integrated within the cylinder, preferably in one of the end sections of this cylinder. Even one or each exhaust control valve may be attached in the same manner to the working cylinder and/or the switch valve may be integrated within. Thereby lines are eliminated between the combined components and in case of integration, connections and sealing areas may also be eliminated; whereby, on one hand, the arrangement of the entire system may be considerably simplified and, on the other hand, its operational dependability may be greatly increased based in the lower danger for leakage. The just-mentioned possibilities are also advantageously applicable in the design of the switch valve in its rocker type construction.
[0041] An expansion of application possibilities and an increase of possible working functions may be reached by a very compact arrangement, whereby within or on the working cylinder A a control logic arrangement is integrated. This control logic arrangement may be flange-mounted to the working cylinder or may be integrated preferably in one of its end sections. From the central control unit there are connection lines going to this control logic arrangement in or on the cylinder, which are used for communication, electric controls, energy supply and supply of working medium. A field bus is thereby preferably planned as communication system. The control logic arrangement may also analyze placement and position signals, for example, of final positions or placement sensors in or on the working cylinder or elements actuated by the cylinder. The control logic arrangement may also regulate control valves to trigger corresponding actions or it may also send back signals and actions to the control unit through these communication lines. | A working cylinder (A) having at least one working chamber ( 6, 7 ) defined by the cylinder barrel ( 1 ), at least one of the end sections ( 2, 3 ) and a piston ( 4 ), at least one supply port ( 9 a , 9 b ) and a exhaust port ( 12 a , 12 b ) for the working medium. The exhaust port ( 12 a , 12 b ) has a valve ( 13 a , 13 b ) that may be regulated by the pressure of the working medium, which is applied at the supply port ( 9 a , 9 b ) in order to obtain a smaller dimension of at least the valve and to better utilize the already existing space, specifically within the cylinder, and to better and more efficiently adjust the output capacity of the individual elements. A valve (V), particularly a switch valve (W) of a rocker valve design has therefore at least one inlet ( 16 ) and at least one outlet ( 17 a , 17 b ) for the working medium, as wells as at least one control port ( 18 ). The cylinder is characterized by a discharge channel ( 19, 19 a ; 38 a , 38 b ) for the working medium, originating from a location between the valve element ( 15; 31, 33 ) of the valve and at least one outlet ( 17 a , 17 b ), whereby this discharge channel has a discharge or exhaust valve ( 20, 22; 36 a , 36 b ), which may be regulated electrically or by the pressure applied to the control port. The pressure-actuated working unit comprises a pneumatic working cylinder (A) with exhaust valves ( 27 a , 27 b ), a valve (V, W) and exhaust control valves ( 24 a , 24 b ; 30 ) as well as only one pressure line ( 29 a , 29 b ) to each working chamber ( 6, 7 ) in the cylinder (A). | 5 |
FIELD OF THE INVENTION
[0001] The present invention relates to tubular connections provided with features that enhance their performance in applications where drilling is conducted with joints of casing joined by such tubular connections. In particular, this invention relates to wellbore casing connections having enhanced wear resistance over at least some portion of their exterior surfaces.
BACKGROUND OF THE INVENTION
[0002] Lengths of tubulars used to drill and complete bore holes in earth materials, referred to as joints, are typically joined by threaded connections to form a long assembly referred to as a drill string. Numerous threaded connection geometries are employed to provide sealing and load carrying capacities to meet drilling, installation and operating requirements. Of these geometries, connections having an external diameter greater than the pipe body are the most widely used. Thus the majority length of a typical drill string is comprised of alternating long lengths of generally cylindrical pipe separated by relatively short externally upset intervals at the connections.
[0003] Within the context of petroleum drilling and well completion, wells are typically constructed by drilling the well bore using one tubular string, largely comprised of drill pipe, then removing the drill pipe string and completing the well by installing a second tubular string, referred to as casing, which is subsequently permanently cemented in place. The tubular strings are formed by connecting joints of pipe with threaded connections. With this historic method of well construction, both the drill pipe and casing joint designs are separately optimized for the different performance requirements of the drilling and completion operations respectively. More specifically, the drill pipe connections must typically accommodate more torque to drill, than is required during completion, and must resist wear that occurs where the connection is in contact with the abrasive borehole wall during extended periods of drilling rotation. The tendency toward wear is strongly dependent on the lateral forces that arise at the points of contact between the drill string and borehole. These contact forces result from the interaction of several variables, but may be generally attributed to: inertia loads required to react the tendency of the rotating drill string to whirl, reaction of lateral load induced by the axial load transferred along the string through intervals of curvature and gravity loads in deviated intervals. Concentration of all or a majority of the wall contact load over the short upset interval containing the connection tends to exacerbate wear at these locations. This wear has the effect of generally reducing the diameter of the connections. For that reason, it is common industry practice to apply bands or zones of abrasion resistant coatings around the circumference of the drill pipe connections, referred to as hardbanding or hardfacing, to build up the diameter of the connection and thus provide a sacrificial layer of slow wearing material. U.S. Pat. Nos. 4,665,996 and 6,375,895 are two examples describing the materials and application methods used to apply such surface preparations to drill pipe tool joints.
[0004] Recent advances in drilling technology have enabled wells to be drilled and completed with a single casing string, eliminating the need to ‘trip’ the drill pipe in and out of the hole to service the bit and make room for the casing upon completion of drilling. This technology employs a wireline retrievable bottom hole drilling assembly capable of deployment on the distal end of casing strings. Development of the technology was initially motivated by potential cost savings arising from reduced drilling time and the expense of providing and maintaining the drill string, plus various technical advantages, such as reduced risk of well caving before installation of the casing. In addition to drilling, this technology finds utility in casing running applications where reaming is required to resize the borehole.
[0005] The established performance requirements for casing are only those required to meet the needs of historic well construction methods. The new use of casing to drill, naturally changes the performance requirements of the casing string. Such changes include increased torque capacity required to drill with the casing connections, but did not initially anticipate the need for increased wear resistance particularly in relatively straight wells where lateral forces arising from curvature and gravity are minimal. This expectation was based on the shorter exposure time to conditions of rotating wear likely for casing strings compared to drill pipe. (Drill pipe is used to drill many wells, resulting in extended exposure of drill pipe connections to conditions of rotating wear. In contrast, the application using a casing string to drill, deliberately only intends to expose the connections to rotating wear conditions for the time required to drill the single well interval to be cased by that string.)
[0006] However, it has been discovered that drilling with casing strings using industry standard threaded and coupled buttress (BTC) connections, having tapered pipe thread geometries specified by the American Petroleum Institute (API) and equipped with shoulder rings such as, for example, those described in Canadian Patent Application 2,311,156, frequently causes eccentric wear in the region of the connection. This wear may locally reduce the coupling side wall thickness until the coupling radius, in the region of wear, is little more than the pipe body. This amount of wear may occur during even a fraction of the relatively short period required to drill a single well interval in a nearly vertical well. As will be appreciated by one skilled in the art, this wear substantially compromises the load and sealing capacity of the connection.
[0007] This eccentric wear mechanism arises because the straightness of these connections are not as tightly controlled as in drill pipe, since the historic use of casing only contemplates the requirements of running, cementing and well access and not drilling. Thus a small bend in the string axis often occurs across the connections. Such bends tend to preferentially force the connections against the borehole wall at the ‘outside’ of the bends. The lateral wall contact force arising at these points of contact is strongly dependent on whether or not the lateral deflection imposed by the bend angles in the axially loaded casing is sufficient to interfere with the confining bore hole. This lateral interference acts to displace the casing string from its neutral position at the points of contact with the borehole, the casing string behaving as a long beam bent at the connections and restrained by the borehole. Particularly, where such lateral interference occurs between connections spaced one joint apart, the lateral load and hence wear rate is much greater than occurs over comparably ‘straight’ intervals.
[0008] For example, the connection bend angles were inferred a sample of typical 7 inch (178 mm) API buttress threaded and coupled (BTC) casing joints. These magnitudes were used to calculate the possible maximum lateral load arising from this load mechanism, were such casing joints assembled into a casing string and placed in a borehole drilled with a bit size of 8.5 inches (216 mm). It was found that, with negligible axial load, a lateral force of at least 1000 lbf (4450N) could be present if the casing string were so confined in an interval.
[0009] As described above, this lateral load mechanism is not normally present in drill pipe strings placed in a bore hole because the connections in those strings are typically straighter and the tube bodies flexurally less rigid than the same respective components of a casing string assembly. Furthermore, unlike the other lateral loading mechanisms which result in relatively axi-symmetric wear of the connection, wear resulting from the connection bend angle is non-axi-symmetric or eccentric.
[0010] This eccentric wear could be mitigated by providing connections with increased straightness. In certain applications this alternative may be preferable. However in general this will increase manufacturing cost and prevent the use of readily available tubulars. Furthermore, the presence of this new lateral wall contact load, while discovered to produce an unfavorable tendency toward excess wear, was simultaneously discovered to have a beneficial effect by improving borehole wall stability and reducing the risk of lost circulation when compared to drilling with straight drill pipe strings.
[0011] Excess wear can be avoided by use of a separate device, termed a wear band, as disclosed in Cdn. Patent App 2,353,249. The disclosed wear band includes a band of wear resistant material and is structurally attached to the casing adjacent the connection by crimping. This solution is effective and provides a readily implemented means enhance the usefulness of casing joints having standard non-wear resistant connections for casing drilling or reaming. However, the method requires additional handling and operations to crimp the wear bands to the casing joints with associated labour, capital and logistical overburden costs, plus introducing a longer upset interval length in the region of the connection, which longer interval must be accommodated by the pipe handling, running and drilling equipment.
SUMMARY OF THE INVENTION
[0012] A wear resistant connection has been invented for joining lengths of casing tubulars into assemblies referred to as strings. The wear resistant connection of the present invention provides a means to substantially prevent loss of material from the exterior surface of the tube wall, in the region of the connection, caused by rotating wear mechanisms present where such strings are placed in boreholes and rotated. In one embodiment, this wear resistant connection provides resistance to eccentric rotating wear mechanisms arising from the bend angle either accidentally or deliberately present in casing connections.
[0013] For the purpose of this invention, a connection is understood broadly to mean any arrangement or device that joins the ends of casing tubulars to create a section over which a structural union is arranged so that the axes of the joined tubulars is substantially continuous across the connection interval, and while generally straight, may have a small bend either accidentally or deliberately introduced. Understood thus, the connection of the present invention includes but is not limited to welded connections, integral connections and threaded and coupled connections. Where an upset interval is associated with such a connection, references to the connection are understood to include this upset interval. Where the connection is made without an upset interval, i.e., an externally flush connection, reference to the connection is understood to include a section of the joined casing tubulars having a length of at least 10 casing diameters on each side of the actual joint (i.e. the weld) between the casing tubulars.
[0014] Thus in accordance with a broad aspect of the present invention, a casing connection is provided having an exterior surface, at least some portion of which includes a wear resistant material.
[0015] The casing connection is preferably selected to be useful for drilling with casing.
[0016] The wear resistant material can be arranged to at least overlap the circumferentially oriented location forming the outside of any bend that may be accidentally or intentionally imposed across the connection.
[0017] The wear resistant material may be integral to the connection, obtained by surface hardness treatment such as boronizing, nitriding or case hardening or applied thereto such as by use of a coating such as hardfacing. The relatively high cost of the applying, working with and forming wear resistant materials encourages a reduction in the size of the area covered and thickness of material.
[0018] The vast majority of well bores are lined with metal casing strings having threaded connections. Therefore to be most readily implemented, wear resistance of metal casing connections is best provided in a manner which accommodates existing thread-forms, sealing geometries and bend magnitude tolerances. Such existing threaded connections include the thread-forms and sealing geometries comprising so called premium connections, in addition to both integral and threaded and coupled American Petroleum Institute (API) specified geometries. (Reference herein to a ‘thread-form’ is generally understood to include the seal geometry if present, unless these two components of the connection geometry are specifically separated in the context.) This accommodation of existing geometry extends to the connection diameter where it is preferable to provide wear resistance without a significant increase in outside diameter to avoid correlatively increasing the annular flow resistance, where such a wear resistant connection is deployed in a casing string within a well bore.
[0019] It is advantageous to adapt existing threaded connection geometries to provide locations where wear resistant materials can be most economically and least invasively applied to the connection, i.e., without significantly altering the existing connections with respect to seal and structural performance, while providing adequate protection against wear from rotation while drilling. In particular, preferably the wear resistant material is provided at the lower or leading end of the coupling (leading is defined with respect to the axial direction of travel while drilling), as the upset diameter change from the pipe body to the coupling occurring at this location tends to promote preferential wear while drilling with casing.
[0020] Threaded and coupled connections according to the present invention can include an internally threaded coupling having an upper end, a lower end and generally cylindrical exterior surface, as typically provided for such couplings, where wear resistant surface treatment or coating material is disposed axi-symmetrically on said external surface over one or more axial intervals to form one or more hardbands of diameter somewhat greater than the diameter of the generally cylindrical exterior surface. Said axial interval length and coating thickness are chosen, based on application requirements, to provide sufficient volume of material to resist wearing through to the base metal. Wear resistant surface treatment or coating material is axi-symmetrically distributed to accommodate the random distribution of bend angle and hence circumferential location of connection contact with the well bore.
[0021] For most of these geometries, wear resistance can be provided by applying coatings resistant to abrasive wear to the exterior surface of the connection. Such coatings are commonly referred to as hardfacing. These coatings are applied using a variety of techniques and materials, but typically the bond chemistry and mechanics require heat input to obtain the elevated temperature required to create a strong bond between the coating and metal substrate. It is therefore necessary to consider the effects of this heat input and bond chemistry on the metal substrate, and in particular to allow for any changes in structural or mechanical performance the heat input and bond chemistry might have.
[0022] In addition, the choice of axial interval location where wear resistant surface treatment or coating is provided is preferably selected to occur at locations where stresses induced by structural and pressure loads are lowest. Such choice of location reduces the risk of connection failure due to crack initiation within the typically brittle coating material.
[0023] However such a suitable region of low stress is often not available for many of the threaded and coupled connection geometries employed by industry. It is therefore a further purpose of the present invention to provide such a suitable region of low stress at one or both ends of the coupling by more preferably providing a coupling having its length and interval of internal threading arranged so that the end hardband interval does not overlap with the internal threaded interval of the coupling. Otherwise stated, relative to the ‘standard’ non-wear resistant coupling geometry a coupling is provided where at least one end and preferably the lower end is modified to provide a generally cylindrical extension which extension or extensions having external and internal surfaces without load bearing threads on which said external surface or surfaces wear resistant surface treatment or coating material such as hardfacing is applied to create a hardband or hardbands of upset diameter. Where only one hardband is required, the lower end is preferred as this end forms the leading edge of the coupling while drilling with casing and protects this region from preferential wear.
[0024] Application of these teachings for placement of wear resistant surface treatment or coating material on the couplings of threaded and coupled connections may be extended to integral connections and externally upset integral connections. As commonly understood in the industry, an integral connection is comprised of an externally threaded pin formed on the end of one tubular screwed into a mating internally threaded box formed on the end of a second tubular. Said internally threaded box having an external largely cylindrical surface and proximal end. Particularly where the connection design is arranged to shoulder on said proximal end when made up to the pin, the stress state in this region is less prone to crack initiation and propagation. To best serve the purposes of the present invention a wear resistant integral connection is therefore provided having a hardband of wear resistant surface treatment or coating material disposed on its proximal end. Relative to the ‘standard’ non-wear resistant geometry of an integral connection box it is more preferable if the proximal end of the box is modified to provide a generally cylindrical extension which extension having external and internal surfaces without load bearing threads on which said external surface wear resistant surface treatment or coating material such as hardfacing is applied axi-symmetrically to create a hardband or hardbands of upset diameter.
[0025] Where the integral connection is formed on externally upset tubulars, such externally upset interval typically extends beyond the depth required to carry the box or pin threaded connection geometry, and in certain applications it may be preferable to provide a hardband on the connection exterior surface at or near the leading end of the upset interval either separately or in combination with a hardband placed at the proximal end of the box. The leading end of the upset interval, thus carrying the hardband, occurs at a location of significantly greater thickness than the pipe body and therefore of significantly reduced stress, but having the further advantage of being positioned at the location of preferential wear. It is therefore an additional purpose of the present invention to provide a wear resistance externally upset tubular connection having an externally upset interval with leading and trailing ends comprising the connection, and having at least one hardband positioned on said leading end.
[0026] The bend magnitude occurring across the connection interval is a function of the pipe end straightness and combined thread axis angle alignment with the pipe axes for integral connections and additionally the coupling thread axes with respect to the coupling for threaded and coupled connections. For industry typical casing connections, the bend magnitude or axis misalignment is not tightly controlled, as for example described in the API Specification 5CT and Standard 5B. Furthermore the bend direction is randomly oriented.
[0027] The wear resistant casing connections of the present invention enjoy further utility when also deliberately provided with a small bend in tubular axis across the connection interval. Where such connections are employed to assemble a plurality of tubular joints to form at least one interval of a casing string placed in a borehole, the bend angle and direction controls the local lateral stess of the casing string within the confines of the borehole. The bend angle and direction may thus be arranged to deflect some or all of the connections into generally radially opposed contact with the borehole wall over an interval of several joints. As will be apparent to one skilled in the art, the lateral forces arising from this contact will tend to increase with increasing bend angle. It will also be apparent that control of the bend direction provides a further means to control this force compared to random orientation of connection bend direction. When such a string is rotated within the confining borehole, the region of connection contact rotates with respect to the borehole causing an axi-symmetric ‘wiping’ action on the interior of the borehole wall, but does not rotate with respect to the connection causing the associated wear mechanism to be non-axi-symmetric, i.e., eccentric. In certain applications, the wiping action thus provided results in axi-symmetric consolidation of the near well bore earth material, reducing risk of sloughing and lost circulation. The degree of consolidation and associated benefits depends on the lateral force generated by the casing as it bears against the borehole wall. Control of the connection bend magnitude, and preferably also the bend direction, enables control of said lateral force exerted and is thus a means to balance the benefits gained by wiping action on the borehole wall against the eccentric wear rate of the connection. This then is the basis for the further utility obtained for the present invention of a wear resistant connection having a controlled small bend.
[0028] In accordance with this further purpose, in one embodiment of the present invention, a wear resistant casing connection is provided having at least some portion of its exterior surface provided with a wear resistant coating or surface treatment and arranged to provide a controlled bend in the axes of the tubulars joined by the connection. Said bend magnitude is selected such that when said bent wear resistant connections are employed to assemble at least some portion of a plurality of tubular joints to form at least one interval of a casing string placed in a borehole, the resulting local directional variations introduced by the bend magnitudes will induce some or all of the bent wear resistant connections to at least contact the borehole wall and induce generally radially opposed contact forces.
[0029] As a means to more predictably control said radially opposed contact forces, in a further embodiment, said wear resistant casing connection of controlled bend is provided having the circumferential direction of the bend controlled with respect to a casing string assembled from such connections. Such control of circumferential direction is preferably selected to provide a repeating pattern between bent connections comprising an interval of an assembled casing string.
[0030] As will be apparent to one skilled in the art, the teachings of the present invention with respect to placement of wear resistant surface treatment or coatings on typical threaded connection geometries to form wear resistant connection where the bend angle and direction is allowed to vary randomly according to existing industry practice apply equally well to connections where the bend angle is controlled. However, where the bend angle is introduced deliberately in the manufacturing process the circumferential location corresponding to the outside of the bend may be readily identified. Since contact with the borehole must occur at this location wear resistant surface treatment or coating material need only be disposed over this region and need not be disposed axi-symmetrically, thus requiring less volume of wear resistant material with consequent opportunity for cost saving.
[0031] In accordance with another aspect of the present invention, there is provided a casing string including an interval over which the bend angle is selected to control the lateral reaction force of the casing string against the borehole wall in which the casing string is intended to extend.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] A further, detailed, description of the invention, briefly described above, will follow by reference to the following drawings of specific embodiments of the invention. These drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. In the drawings:
[0033] FIG. 1 is a perspective view of a wear resistant connection according to one embodiment of the present invention;
[0034] FIG. 2 is a sectional view through the sidewall of the connection shown in FIG. 1 wherein a shoulder ring is included to provide improved torque capacity;
[0035] FIG. 3 is a sectional view through the sidewall of another connection wherein improved torque capacity is provided without a shoulder ring;
[0036] FIG. 4 is a front elevation of a pair of connected casing joints showing the bend angle formed by the connection shown in FIG. 1 ; and
[0037] FIG. 5 is a partially cut away view through another connection, where the coupling bend angle is controlled.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0038] According to the present invention, a wear resistant casing connection is provided for joining two lengths or joints of tubulars suitable for drilling with casing. In its preferred embodiment, the wear resistant casing connection is generally of a threaded and coupled nature and more preferably employs a thread-form geometry compatible with a buttress connection as specified by the American Petroleum Institute (API).
[0039] Referring to FIGS. 1 and 2 , an assembled threaded and coupled wear resistant connection 1 is shown according to one embodiment of the invention including a lower joint 2 with threaded ends 5 a, 5 b, an internally threaded coupling 3 and an upper joint 4 with threaded ends 7 a, 7 b. As commonly understood in the industry, the connection is assembled or ‘made up’ by screwing the externally threaded mill end pin 5 a of lower joint 2 , into the mill end box 6 of coupling 3 and screwing the field end pin 7 b of upper joint 4 into the field end box 8 of coupling 3 to form a sealing structural union. The generally cylindrical coupling 3 includes an upper end 9 , a lower end 10 and a hardband 13 formed from application of hardfacing axi-symmetrically about the circumference of the coupling on the exterior surface 11 adjacent lower end 10 . In the illustrated embodiment, the hardfacing is applied in a substantially uniform thickness to form the hardband.
[0040] The main body of coupling 3 is arranged to generally match the thread-form geometry, tolerancing and length of an API specified buttress connection, where the lower end 10 is formed as a generally cylindrical extension of the main body. The extension extends out beyond the threads 6 a of the mill box end a sufficient length to carry the hardband 13 such that the hardband does not radially overlap the threaded interval of the mill end box 6 .
[0041] The outer diameter of the coupling at hardband 13 is preferably selected to be greater than the diameter of the coupling outer surface 11 to such that the hardband preferentially contacts the borehole wall when connection 1 is employed in a casing string. However, when selecting the outer diameter of the hardband, care should be taken, with consideration as to the borehole diameter in which the coupling is to be used to reduce adverse effects on annular flow.
[0042] A multi-lobe shoulder ring 15 is disposed in the coupling centre region, between the mill and field end pins 5 a, 7 b. Under application of sufficient torque the mill and field end pins 5 a, 7 b are caused to abut ring 15 to thus increase torque capacity in support of drilling with casing as described in Canadian Patent Application 2,311,156.
[0043] The illustrated embodiment of FIGS. 1 and 2 , thus provides a wear resistant connection where the manufacturing of the pin and box thread-forms is compatible with existing industry practice with respect to geometry, tolerance and make-up practice.
[0044] Referring now to FIG. 3 , an alternate embodiment of a wear resistance connection is shown where the geometry of the coupling 3 is arranged to support direct abutment of the field and mill end pins 5 a, 7 b, under application of sufficient torque, eliminating the need to use a torque ring. To support this alternate embodiment, the thread form geometry and tolerancing of the coupling is adjusted, relative to the API specified standards, to accommodate pin ends made according the API specified standards for geometry and tolerancing. The coupling is adjusted by reducing the length of the thread-form of the coupling main body to eliminate the pin end standoff and by adjusting the diameter and taper tolerance of boxes 6 , 8 to ensure that the smallest API allowable field or mill end pins, when made up to the centre of the coupling main body, will result in sufficient radial interference to create the normally intended thread seal. Thus configured, the connection is preferably made up using position control to ensure the pin ends 5 a, 7 b are brought into abutment at generally the center of the coupling. The embodiment of FIG. 3 thus offers compatibility with standard forms of casing joints with threaded pin ends, but is shorter than a coupling according to FIG. 2 and achieves increased torque capacity over a standard non-shouldering API connection without requiring a shoulder ring, thus reducing cost and complexity.
[0045] The bend angle and direction formed across the assembled connection 1 depends on the cumulative effect of the thread axis angle misalignments and the relative direction of the misalignments for the pins 5 a, 7 b and boxes 6 , 8 after make-up. With reference now to FIG. 4 , the bend angle α is defined as the angle change between a first line 2 a extending though the center points 5 ax, 5 bx at the ends of the lower joint 2 and a second line extending though the center points 7 ax, 7 bx at the ends of the upper joint 4 in the connection. The bend angle or connection straightness is dependant on variables generally controlled by specifications known to the industry such as: pipe straightness, pin geometry parameters such as imperfect thread limits for buttress threads, coupling thread angular misalignment and make-up position. Prevalent industry practice for control of these variables results in randomly controlled casing connection bend magnitudes, where a significant number of connection bend angles are greater than allowed by comparable drill pipe specifications. Therefore, when a plurality of such connections are employed to form a tubular casing string placed in a bore hole, joint to joint local directional variations interfering with the borehole confinement are likely. As noted hereinbefore, this interference is frequently great enough to cause large radial or lateral reaction loads between the connection outside bend surface 16 and the confining borehole wall and, thus, there is a need to protect the connections against excess rates of wear under conditions of extended rotation, such as in drilling with said tubular casing string.
[0046] While the wear resistant connections shown in FIGS. 2 and 3 are useful for applications where the bend angle α is allowed to vary randomly in accordance with typical industry practice for manufacture and assembly of threaded and coupled casing connections, in certain applications it is desirable to control the magnitude of said lateral reaction force in at least one interval of an assembled casing string, which lateral reaction force is dependent on several design variables including: casing flexural stiffness, spacing between contacting bent connections, axial load, relative radial orientation of connection bends and radial interference of local bent section as controlled by the magnitude of the connection bend angle α.
[0047] To control of lateral load arising in an interval of a casing string, it is useful to control the bend angle geometry and spacing along that string interval. This can be done by surveying couplings and casing joints to determine the bend angle magnitude at a connection of selected ones of the couplings and casing joints and selecting the couplings and casing joints to be used in the string interval.
[0048] Referring now to FIG. 5 , in an alternate embodiment of the present invention a bent wear resistant connection 101 largely as shown in FIG. 2 is provided, but where the center axis 6 x of the mill end box 6 and the center axis 8 x of the field end box 8 are offset out of alignment to form a bent coupling 103 having an angle β between axes 6 x and 8 x. A wear pad 113 is positioned on the outer surface of the coupling about the circumferential location defined by the outside bend 16 of bent coupling 103 . Coupling 103 accommodates a shoulder ring 115 which substantially conforms to the bend of the coupling. In particular, shoulder ring 115 includes end faces 115 a, 115 b defining planes that are not parallel, such that the width of the ring varies from a narrow wall 115 c to a long wall 115 d. The ring is set within the coupling bore having its long wall 115 d positioned radially inwardly of outside bend 16 of the bent coupling 103 . The planes of end faces 115 a, 115 b therebetween define an angle selected to be similar to that of angle β.
[0049] In use, the bent coupling can be employed to achieve further control of said lateral force arising from confinement within a borehole, by selecting the frequency of bent connections and, thereby the spacing therebetween, and by controlling the relative orientation of outside bend position 16 between sequential bent couplings employed to connect a plurality of tubular joints forming an interval in a casing string. To conveniently select the bend orientation of the connection during make up of a string, means, such as a power tong, can be used to apply torque to the coupling for control of mill end make-up position. Final mill end make-up position may then be selected to align the outside bend position of sequential connections at, for example, positions 180° apart or other similar pattern as required.
[0050] In a further embodiment, the casing joint pin ends used can have the misalignment tolerance of their thread axes reduced from typical industry practice to further improve control of their bend angle.
[0051] It will be apparent that many other changes may be made to the illustrative embodiments, while falling within the scope of the invention and it is intended that all such changes be covered by the claims appended hereto. | A wear resistant casing connection including a wear resistant portion on its exterior surface is taught. A casing connection having a controlled bend angle is also taught. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates generally to knitted socks, and more particularly to a seamless pedorthic sock and method of knitting same as an aid in helping to prevent and alleviate painful and disabling conditions in areas of the foot and of the leg above the sock.
Prophylactic foot care is especially important to avoid potential hazards of excessive heat or cold, new shoes, constricting or mended socks, or going barefoot. Socks serve as the interface between the feet and with any surface they might come into contact to provide cushioning, warmth, absorption of moisture and, in general, a healthy environment. However, foot problems such as poor circulation, sensitive skin areas, ulcerated areas and calluses caused by friction are still common occurrences which are aggravated in various degrees by the common varieties of socks. As the skin rubs within the confines of the sock and shoe, these friction points persist to irritate and may eventually ulcerate internally. This can be debilitating with a possible loss of mobility.
Many styles of socks are traditionally knitted on small diameter circular knitting machines including tube or crew socks. The crew style contains a pocket fashioned to accommodate the heel of the foot, whereas the wearer's foot makes the heel pocket in the tube-style sock. A wide array of thin dress socks, cushioned support socks, heavyweight hunting socks, etc. are possible with different combinations of yarn, needle cylinder diameters and number of needles per cylinder. However, inherent limitations in the knitting process produce these socks with an open toe end which must be closed by a seaming operation usually performed on a sewing machine. The leg area of the sock is usually narrow and elasticized for fitting tightly around the wearer's leg to keep it from slipping down during use.
These common varieties of sock with the seamed toe area and snug fitting leg area has been the only sock generally available for protection against friction and abrasion. While generally satisfactory for normal use, it is unsuitable for persons with certain afflictions such as diabetes, edema, ischemia and obesity. The seaming in the toe area of the sock leaves a ridge either at the end or over the top of the wearer's toe. Either site may irritate the toe area. If left unattended, a skin lesion can easily become infected, and in extreme cases lead to amputation of the foot or leg. This is especially so for severely afflicted diabetics with peripheral neuropathy since the foot becomes insensitive to pain. A tightly fitting elastic top should also be avoided as any constriction may increase the possibility of edema in the upper leg area above the sock and infection.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a seamless pedorthic sock which has a low friction interface between the wearer's foot and any surface it might contact, and a nonconstricting top with just enough compression to keep the sock in position above the ankle without impairing vascular circulation to the foot.
Another object is to provide a pedorthic sock which is particularly suitable for therapeutic use by persons afflicted with diabetes, edema, ischemia and obesity.
Still another object is to provide a pedorthic sock having a plating of inner and outer faces of different yarns for optimizing comfort and therapeutic effects.
A further object is to provide a method for producing a seamless pedorthic sock in one continuous operation on a flatbed knitting machine.
These and other objects and novel features for the pedorthic sock according to the invention are accomplished with seamless toe, foot and leg areas knitted with a plating of two relatively low stretch yarns. A narrow band or bands of non-constricting elastic yarn, or stretchable yarn with memory, are located along the length of the leg area for keeping the sock in position above the ankle without imparting any excessive constrictions.
The sock is produced in one continuous integral operation on a programmable flatbed knitting machine with a row of needles along each of front and back beds. It begins by knitting a seamless closure of the toe area with low stretch yarns. First, the knitting gradually tapers inward on both sides of one panel from a full width of the sock for a predetermined toe length, and then gradually tapers outward on both sides of an opposed panel to the full width. Loops at opposite extremities of each course are integrally joined.
Knitting with all needles activated in both beds then continues for the full length of the foot area. Once the desired foot length is reached, the machine automatically begins knitting a heel pocket by gradually tapering both sides of one panel inward for a desired depth, and then outward to the full width of the sock to complete the heel pocket. Multiple gores, not shown, may be knitted into the toe or heel pocket for additional comfort.
Upon completing the heel pocket, the leg area of the sock is knitted with the low stretch yarns. A stretchable yarn is introduced in at least one location along its length to keep the sock in position on the wearer without creating excessive compression on the leg. A final finishing course of stretchable yarn is knitted at the top of the sock for preventing it from rolling down the leg and unravelling.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing objects, novel features and advantages of the invention will become more apparent from the following description of the preferred embodiments when taken in conjunction with the accompanying drawings wherein:
FIG. 1 represents a perspective view of a pedorthic sock according to the invention as worn on the foot;
FIG. 1A represents a detailed view of a non-constricting elastic band for holding the sock in position on a leg;
FIG. 2 is a front view of the sock with the front and back panels collapsed flatly against each other;
FIG. 3 is a view of the sock as viewed from the right side of FIG. 2;
FIG. 4 is a rear view of the sock with the front and back panels collapsed flatly against each other; and
FIG. 5 is a view partially cutaway of a fragment of the sock.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings wherein like referenced characters denote like or corresponding parts throughout the several views, there is illustrated in FIG. 1 a seamless crew-style pedorthic sock 10 as worn on the foot according to a preferred embodiment of the invention. The sock is shown in, but is not limited to, a half-knee length with a heel. For instance, it may also be ankle or knee length, or tube-style without departing from the principles of the invention. A terry lining may also be knitted into the various styles. The sock comprises a toe area 12, foot area 14, heel pocket 16 and a leg area 18 knitted with a substantially low stretch yarn 19. Narrow bands 26 in leg area 18 are knitted with a substantially elastic yarn 27 to hold the sock in position on the leg, and a finishing course 28 with a substantially low stretch yarn prevents the top of the sock from rolling down and unravelling.
Sock 10 is knitted on an existing programmable flatbed knitting machine in which yarn carriers traverse back and forth across needles which are arranged along each of front and back beds. The machine is programmed to produce a fabric of plain jersey stitches having wavy horizontal loops on the inner face and vertical columns of loops on the outer face of the sock. Other stitches with or without plating may include, but not be limited to, a tuck and mock rib either singly or in combination with other stitches. The needle spacing, yarn size, yarn tension, and other variables are selected to produce a high quality fabric in the relaxed state having approximate ranges of, but not limited to, 15 to 20 wales per inch and 20 to 25 courses per inch.
A conventional sock fabric knitted with a single yarn on a flatbed machine usually forms narrow columns of close parallel wales on the outer face of the sock which contact the lining of a shoe or other footwear. The inner face usually consists of wavy crosswise rows of loops separated from each other by slight depressions which contact the foot. The texture of the inner face is inherently rough, and lacks the advantages of a sock knit with double yarn plating. By a proper choice of yarns of different textures and properties, the plated knit enhances a sock's versatility.
The schematic cutaway of sock 10 illustrated in FIG. 5 includes a plated knit of two types of low stretch yarns in the outer and inner faces 30 and 32, respectively. Longitudinal or vertical courses 30a of one yarn have closely parallel wales exposed on inner face 30 and transverse or horizontal courses 32a of the other yarn exposed on inner face 32. A combination, for instance, of a smooth yarn, dominant on the inner face 32, reduces friction at the interface of the foot and the sock, and a rougher yarn dominant on the outside face 30 increases the friction at the interface of the sock and the shoe. Similarly, a tacky yarn surface against the foot and a smooth surface against the shoe, or a soft yarn against the foot coupled with a yarn that dissipates moisture on the outside, may satisfy requisite performance characteristics. Other combinations of yarns are possible in order to alleviate areas of irritation while walking, especially those areas with calluses. Other combinations of yarn, of course, are possible depending on the specific malady. A suitable method for plating the sock is disclosed in U.S. Pat. No. 3,451,232.
The knitting process starts near the toe of sock 10 with the yarn carriers feeding the low stretch yarns 27 to opposed needles of the front and back beds to knit a seamless course of stitches along the full breadth W 1 of the sock in the toe area 12 with loops at the course extremities interconnected. All of the back bed needles are then deactivated while the front bed needles continue knitting but are gradually deactivated from the opposite ends of each course to form inwardly tapered sides of a back panel 12a of toe area 12 with a tip 20 of breadth W 2 . The needles of the front row which were deactivated are then reactivated in reverse order to form outwardly tapered sides of a front panel 12b of toe area 12 until the full width W 1 is reached. Loops 22 at the opposite extremities of each course of panels 12a and 12b are joined to form a seamless toe area.
The knitting process with the needles in both beds then continues with back and front panels 14a and 14b, joined in like manner to form foot area 14 up to a course located at the beginning of heel pocket 16 along the back panel 14a as illustrated by dotted line B 1 .
Heel pocket 16 is then formed by inactivating all of the back bed needles while knitting continues on the front bed needles with needles from opposite ends of the course being gradually deactivated to taper a bottom section 16a of heel pocket 16 inward to a suitable breadth W 3 . The same needles deactivated in the front bed are then reactivated to gradually taper a top section 16b outward to the full sock width W 1 at a course, shown by dotted line B 2 , across the back panel 18a of sock 10. The opposite extremities 24 of the courses of sections 16a and 16b are integrally joined by seamless loops to form a pocket.
All the needles in both beds then continue knitting the front and back panels 18a and 18b with low stretch yarns 19 to form leg area 18. The knitting process continues to an intermediate location along the length of leg area 18 where the yarn carriers feed courses of an elastic yarn 19 between courses of the low stretch yarns 19 to form a first narrow non-constricting elastic band 26. The process then returns to knitting with only the low stretch yarns and terminates with a second narrow elastic band 26 and at least one finishing course 28 at the top of the sock.
Of course it is understood the described process can also be accomplished by reversing the needle activation on the front and back beds of the machine. For example, the needles on the front bed could be deactivated while the needles on the back bed are activated to form the front panel of toe area 12 first.
Various types and sizes of yarns are contemplated depending on the individual requirements of the wearer such as softness, moisture absorptivity, elasticity and smoothness. Suitable low stretch yarns 19 include, but are not limited to, single or multiple plies of acrylic, rayon, wool, cotton, polyester, silk and teflon fibers or combinations thereof, in various sizes. Suitable elastic yarns 27 include, but are not limited to, stretchable fibers with restorative memory such as texturized nylon or polyester, or an elastomeric core made of spandex or rubber and covered with any of the above-stated fibers
Some of the many advantages and novel features of the invention should now be readily apparent. For example, a seamless pedorthic sock is provided having a low friction interface between the wearer's foot and with any surface it might contact. The sock is prevented from sliding downward on the leg by non-constricting elastic bands which minimizes the reduction of vascular circulation to the foot. The sock may include plating to provide inner and outer faces of various physical properties for optimizing the therapeutic effect. The sock is particularly suitable for therapeutic use by persons afflicted with diabetes, edema, ischemia and obesity. A unique method is disclosed which enables the sock to be produced in one continuous operation on a programmable flatbed knitting machine.
It will be understood, of course, that various changes in the details, materials, steps and arrangement of part, which have been described and illustrated in order to explain the nature of the invention, may be made by those skilled in the art without departing from the scope of the invention as expressed in the appended claims. | A pedorthic sock having seamless toe area, heel pocket and leg area knitted of two or more low stretch yarns, and narrow bands of nonconstricting elastic yarn located intermediate the length of the leg area and at the top. The socks are produced by a flatbed knitting machine set up with a row of needles on each of front and back beds selectively fed with relatively low stretch yarns and an elastic yarn. The low stretch yarns form a plating knit on the inner and outer faces of the sock to produce desired functional effects. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The application claims the benefit, under 35 U.S.C. §119(e), of U.S. Provisional Application Ser. No. 60/804,235, filed Jun. 8, 2006, the contents of which are incorporated herein by reference.
ORIGIN OF INVENTION
The invention described herein was made by employees of the United States Government and may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.
BACKGROUND OF THE INVENTION
High-performance polyimides are presently employed in a number of applications, for example in joining metals to metals, and in joining metals to composite structures in the aerospace industry. In addition, polyimides are rapidly finding new uses as foam insulation in cryogenic applications and as structural foam, having increased structural stiffness without large weight increases. Foams of various densities and thermal and mechanical properties are now being required for future reusable launch vehicles, maritime ships, and aircraft. Polyimide foam materials have a number of beneficial attributes in these applications, such as high temperature and solvent resistance, flame resistance, low smoke generation, high modulus and chemical and hot water resistance.
Most polymeric cellular solids do not perform well at cryogenic temperatures, are not chemically stable, and are not inherently flame retardant or thermally stable. One polyimide foam is TEEK H developed at NASA Langley Research Center. (U.S. Pat. Nos. 5,994,418; 6,084,000; 6,133,330; 6,180,746; 6,222,007; 6,235,803; and Williams et al. (2005), “Effects of cell structure and density on the properties of high performance polyimide foams,” Polymers for Advance Technologies, 16, 167-174, which are hereby incorporated by reference). TEEK polyimide foam performs well physically, thermally, chemically, and is flame retardant, but improvements are possible.
Improved thermal performance translates to less material required to achieve the same insulation performance, resulting in lighter vehicles. Improved foam materials that have increased thermal and acoustic insulation power with the same or less weight are needed for aerospace, maritime, and other uses.
SUMMARY OF THE INVENTION
The invention involves adding aerogel, which is a material with very low thermal conductivity and excellent acoustic insulation, to a polymer foam to form a composite material. The composite materials have improved thermal insulation ability and excellent physical mechanical properties that make them usable at both extremely low temperatures and extremely high temperatures.
The most common aerogels are composed of silica, and these are flame resistant and maintain their excellent thermal insulation properties at both very low temperatures, e.g., −196° C. (77 K), and very high temperatures, e.g., 200° C. (473 K) or 300° C. (573 K). Preferably the foam is also flame resistant and maintains its insulation properties and mechanical properties, e.g., structure, strength, flexibility, and stability, at both high and low temperatures.
The composite materials have some improved characteristics over the polymer foam because the aerogel improves the thermal insulation and acoustic insulation properties of the polymer foam. Aerogels can provide significant improvements in acoustic damping and reduction in sound transmission. Aerogels can exhibit unexpected attenuation for well-defined frequency bands.
The composite materials also have improved characteristics over the aerogel. Aerogel is very brittle and stiff and difficult to form into desired shapes. The polymer foam adds improved mechanical properties and a reduction in flexural stiffness to the aerogel. The composite materials are also easier to form into desired shapes than aerogels are.
Heat transfer occurs through solid conduction, gas convection (and conduction for low pressures), and radiation. The thermal performance of the composite materials is improved in the following ways. First, the aerogel component reduces the solid-solid contact points and thus reduces heat transfer by solid conduction. Second, the aerogel also reduces the gas convection inside the material due to its nanoporous internal structure. Thus, the overall heat transfer through the composite is further reduced. Third, the invention can also incorporate radiation shielding elements to reduce the radiant heat transfer. These elements can comprise, but are not limited to, aluminum powder or flakes, carbon black, or even embedded layers of aluminum foil or aluminized polymeric film. Higher temperature applications would benefit more by the inclusion of these optional radiation shielding elements.
It as an object of the invention to provide a foam-like product that can be used, for instance, for heat and acoustic insulation on aircraft, spacecraft, and maritime ships in place of currently used foam panels and other foam products. The materials of the invention can also be used in building construction with their combination of light weight, strength, elasticity, ability to be formed into desired shapes, and superior thermal and acoustic insulation power.
The materials have also been found to have utility for storage of cryogens. A cryogenic liquid or gas, such as N 2 or H 2 , adsorbs to the surfaces in aerogel particles. The small pore sizes and sharp angles of curvature in the pores of aerogels alter the thermodynamic state of adsorbed cryogen from the bulk fluid state. The adsorbed fluid has a greatly reduced vapor pressure and a higher effective vaporization enthalpy (H v ) than the bulk liquid. The enormous surface area of aerogel provides a large capacity for cryogen adsorption and storage. This allows storage of the cryogen at a high density with a reduced boil-off rate. The composite materials also facilitate more effective handling of cryogenic fluids (liquid and vapor phase) in space at zero or reduced gravity.
In the composite materials, a mostly open-cell foam allows cryogen access to the aerogel, but holds the aerogel in place, which prevents movement of aerogel beads or sloshing of fluid mixed with the aerogel. The foam also provides insulation around the aerogel, which reduces the boil-off rate of cryogen from the aerogel.
Liquid hydrogen and oxygen are stored as fuel on spacecraft. The fuel tanks experience extraordinary variances of temperature. The interior of the tank is at −253° C. (20 K), the boiling point of hydrogen, and the exterior can be at over 200° C. (473 K) due to friction with air on takeoff or landing. Thus, materials capable of performing at both these temperature extremes are required.
Cryogenic fluids are typically stored in vacuum-jacketed vessels that are hollow and contain the fluid in the same way a cup does. With movement in ground, air, and space vehicles, slosh can be a problem in such containers. Additionally, a broken vacuum can result in a rapid pressure increase due to boil off of the cryogen, which can lead to a hazardous situation. An impact that breaks the vessel also would cause liquid to leak and rapid boil off, resulting in a very hazardous situation with a fuel such as liquid hydrogen. Storage in the composite materials solves these problems of slosh and susceptibility to an impact that would cause liquid leakage and rapid boil off. The cryogenic fluid is nano-sequestered in aerogel pores, so that no bulk liquid is present that can rapidly leak out. The foam provides insulation for the aerogel to slow the rate of boil off, even if the material is torn by shrapnel.
Thus, one embodiment of the invention provides a flame resistant composite material comprising a flame-resistant polymer foam containing a flame-resistant aerogel.
Another embodiment of the invention provides a composite material comprising a polyimide foam containing an aerogel.
Another embodiment of the invention provides a cryogen storage apparatus comprising: (a) a composite material comprising: (i) a polymer foam; containing and holding immobile relative to the polymer foam and (ii) an aerogel; wherein the polymer foam forms one or more openings through the foam that allow fluid access to the aerogel; and the aerogel provides a storage medium for a cryogen.
Another embodiment of the invention provides a cooling apparatus comprising: (a) a composite material comprising: (i) a polymer foam containing and holding immobile relative to the polymer foam and (ii) an aerogel; wherein the polymer foam forms one or more openings through the foam that allow fluid access to the aerogel; the aerogel provides a storage medium for a cryogen; and the apparatus is adapted to store a cryogen in the aerogel to cool a space surrounding the apparatus.
Another embodiment of the invention provides a method of storing a cryogen gas or fluid comprising: contacting the cryogen with a composite material comprising (a) a polymer foam containing and holding immobile relative to the polymer foam and (b) an aerogel; wherein the polymer foam forms openings through the foam that allow fluid access to the aerogel; the aerogel provides a storage medium for a cryogen; and the cryogen passes through the one or more openings through the polymer foam to contact the aerogel for storage.
Another embodiment of the invention provides an article of manufacture comprising a composite material of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plot of thermal conductivity and density measurements of individual TEEK and TEEK/aerogel composite foam materials.
FIG. 2 is a plot of averaged thermal conductivity and density measurements of TEEK and TEEK/aerogel composite foam materials.
FIG. 3 is a plot of thermal conductivity and density measurements of TEEK and TEEK/aerogel composite foam materials having approximately the same density.
FIG. 4A is a plot of liquid nitrogen storage versus time in a composite material containing an aerogel blanket within a TEEK foam.
FIG. 4B is a plot of liquid nitrogen storage versus time in a composite material containing aerogel beads in a pocket within a TEEK foam.
DETAILED DESCRIPTION OF THE INVENTION
A “flame resistant” material, as used herein, refers to a material that has an oxygen index of 25% or above. The “oxygen index” of a material refers to the lowest percent of oxygen in an oxygen/nitrogen atmosphere in which the material will just maintain candle-like burning when ignited from above.
Peak heat release rates (PHRRs) are another measure of the degree of flame resistance. PHRRs are determined using ASTM E1354. Cone calorimetry analysis utilizes the oxygen consumption principle during combustion as a measure of heat release. The rate of heat release is a major factor that determines the size of a fire. The oxygen consumption principle states that there is a constant relationship between the mass of oxygen consumed from the air and the amount of heat released.
The term “PITA” as used herein refers to composite materials with a pocket of aerogel particles within an envelope of foam.
As used herein, the term “aerogel” refers to a highly porous material of low density, which is prepared by forming a gel and then removing liquid from the gel while substantially retaining the gel structure. Aerogels have open-cell microporous or mesoporous structures. Typically, they have pore sizes of less than 200 nm and surface areas of greater than 100 m 2 per gram. They often have low densities, e.g., from 200 mg/cc down to as little as 1 mg/cc.
According to a narrower definition, aerogels are materials in which the liquid has been removed from the gel under supercritical conditions. Most commonly the liquid is removed with supercritical carbon dioxide. The term “xerogel” as used herein refers to a type of aerogel in which the liquid has been removed from the gel by a process other than supercritical fluid extraction, including drying under subcritical conditions or removal of the liquid from the frozen state by sublimation.
The most common aerogel material is silica (SiO 2 ). Other materials can be used, including other metal oxides such as alumina (Al 2 O 3 ), carbon, and polymers such as polyimide.
Aerogels are commercially available from several sources. Aerogels prepared by supercritical fluid extraction or by subcritical drying are available from Cabot Corp. (Billenca, Mass.), Aspen Aerogel, Inc. (Northborough, Mass.), Hoechst, A.G. (Germany), and American Aerogel Corp. (Rochester, N.Y.).
Aerogels can be prepared by methods well known in the art. Briefly, a gel is prepared, then fluid is removed by any suitable method that substantially preserves the gel structure and pore size. The method of fluid removal can be supercritical fluid extraction, evaporation of liquid, or freeze-drying. The gel can be cast in particles to match the desired final aerogel. As examples, particular specific methods of preparing aerogels will now be described. In one technique, silica gels can be prepared by pouring slowly with stirring a sodium silicate (Na 2 SiO 3 ) solution of specific density 1.15 in water into an equal volume of 6 M HCl. The solution is allowed to gel in dishes for 24 hours at room temperature, and then washed with water until no chloride ion is found in the wash water. The gel may then be washed with ethanol and then the ethanol removed by heating under pressure to above the critical temperature and then removing the supercritical alcohol. Alternatively, liquid in a gel can be removed with supercritical carbon dioxide. In this process, if necessary, the gel is washed to replace liquid in the gel with a liquid that is miscible with CO 2 (e.g., water, dimethylsulfoxide, acetone, methanol, amyl alcohol, etc.). The gel is then washed with CO 2 at a temperature and pressure above the critical point, e.g., 37° C. and 82 bar. Slow isothermal depressurization is then used to remove the CO 2 , e.g., 0.05 bar/min at 37° C.
In another method, a final solution of 0.29 M resorcinol, 0.57 M formaldehyde, and 1.5 mM Na 2 CO 3 is prepared and sealed into ampules. The sealed ampules are placed in an oven at 85° C. for 7 days. The ampules are then cooled and broken to remove the gel. The gel may be washed with acetone, and the acetone then removed from the gel with evaporation at subcritical temperatures and pressures.
In another method, an organic or inorganic gel having surface ROH groups is treated in the wet state with a surface modifying agent of the formula R x MX y , where R is an organic group, M is Si or Al, and X is a halogen. See U.S. Pat. No. 5,565,142. An example is trimethylchlorosilane. The surface modifying agent decreases the surface tension of the liquid in the gel, allowing the liquid to be evaporated without shrinking the gel.
Other aerogels and methods to prepare them are described in, e.g., Rigacci, 2004, “Preparation of Polyurethane-Based Aerogels and Xerogels for Thermal Superinsulation,” J. Non - crystalline Solids 350:372-378; U.S. Pat. No. 5,795,556; U.S. Pat. No. 5,680,713; U.S. Pat. No. 5,306,555; and U.S. Pat. No. 7,074,880.
Aerogels are excellent thermal insulators. They minimize conduction because of the tortuous path through the aerogel nanostructure. They minimize convection because of the small pore sizes. If doped with infrared-suppressing dopants, they may also minimize radiative heat transfer; however aerogels are often very brittle and fragile, which limits their utility in some applications.
Aerogels that are formed by supercritical fluid extraction are usually superior to xerogel aerogels (formed using other methods of liquid removal) in being somewhat better insulators, more lightweight, and having greater surface area. This is because supercritical fluid extraction usually better preserves the gel structure as compared to other methods of liquid removal from gels. But supercritical fluid extraction requires extremes of pressure and/or temperature, and it is easier and less expensive to remove liquid from gels by other means, i.e., to form xerogels. And the properties of xerogels can often be made very close to the properties of aerogels formed by supercritical fluid extraction.
The invention involves composite materials comprising a polymer foam and an aerogel.
In one embodiment, the composite materials, the polymer foam, and the aerogel are all flame resistant.
In a preferred embodiment, the aerogel is a silica aerogel.
In one embodiment, the aerogel is a metal oxide aerogel, e.g., alumina aerogel.
The composite materials are preferably usable at temperature extremes, e.g., at above 200° C. (473 K) or below −196° C. (77 K).
In one embodiment, the polymer foam has a glass transition temperature above 200° C. (473 K).
In another embodiment, the polymer foam has an elastic compression strain at −196° C. (77 K) that is at least 0.05% and is at least half the elastic compression strain at 25° C. (298 K).
The composite materials are good thermal and acoustic insulators. In preferred embodiments, the composite material has a thermal conductivity at least 10% lower than the thermal conductivity of the polymer foam.
The polymer foam of the composite materials can be predominantly closed-cell or open-cell.
In some embodiments, the closed-cell content of the polymer foam is at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, or at least 90%.
In other embodiments, the open-cell content of the polymer foam is at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, or at least 90%.
Closed-cell foams are generally better insulators than open-cell foams. Open-cell foams are generally more compressible. Open-cell foams are also useful in embodiments involving cryogen storage, because cryogen can pass through the open-cell structure to access internal aerogel.
In some embodiments, the polymer foam is made from friable balloons. This involves partial inflation of a solid residuum powder before the final foaming process. Friable balloons facilitate an increase in closed-cell content, particularly at low densities. At higher densities, the friable balloons are crushed and break, the closed-cell content of the foam decreases. Maximum closed-cell content with foam prepared from TEEK H friable balloons is about 80% and occurs at a density of about 0.045 g/cm 3 see foams prepared as described in Williams, M. K. et al. 2005, “Effects of cell structure and density on the properties of high performance polyimide foams,” Polymers for Advanced Technologies 16:167-174, incorporated by reference. The maximum closed-cell content of TEEK-H can be increased above that level if balloons are sifted to remove very small particles that are common in the as-formed balloons. A high closed-cell content at higher densities can also be achieved by first forming smaller balloons by the use of less solvent so the balloons do not expand as much.
The polymer of the polymer foam can be any suitable polymer. In some embodiments, it is a polyimide. In a more specific embodiment, it is a heteroaromatic polyimide.
In a more specific embodiment, the heteroaromatic polyimide polymer of the polymer foam is a polymer of formula (I):
wherein R is a tetravalent aromatic radical having 1 to 5 benzenoid-unsaturated rings of 6 carbon atoms, the 4 carbonyl groups being directly bonded to different carbon atoms in a benzene ring of the R radical, each pair of carbonyl groups being bonded to adjacent carbon atoms in the benzene ring of the R radical; and R′ is a divalent aromatic radical having 1 to 5 benzenoid-unsaturated rings of 6 carbon atoms, the amino groups being directly bonded to different carbon atoms in a benzene ring of the R′ radical.
In a more specific embodiment of the composite materials, the polymer of the polymer foam is a polymer of formula (II) or (III)
wherein X is —O— or —C(═O)— and Y is —O— or —SO 2 —.
In a preferred embodiment, the polymer is a polymer of formula III wherein X is —O— and Y is —O—. This is known as TEEK H and is used in the Examples below.
Foams of formula I, II, and III and their methods of preparation are described further in U.S. Pat. Nos. 5,994,418; 6,084,000; 6,133,330; 6,180,746; 6,222,007; and 6,235,803 incorporated herein by reference.
TEEK is very flame resistant. The TEEK H polymer foam made from friable balloons has a peak heat release rate (PHRR) of approximately 24 kW/m 2 at an irradiance of 50 kW/m 2 . TEEK H foam made from solid residuum has a PHRR slightly higher but still less than 60 kW/m 2 at the same irradiance level.
In specific embodiments of the composite materials of the invention, the polymer foam has a PHRR at an irradiance of 50 kW/m 2 of less than 100 kW/m 2 , less than 60 kW/m 2 , less than 50 kW/m 2 , or less than 30 kW/m 2 . In other embodiments, the polymer foam has a PHRR at an irradiance of 50 kW/m 2 of 10-100, 20-100, 10-60, or 20-60 kW/m 2 .
The polymer foam contains the aerogel in the composite materials. As used herein, the term “contains” means that the polymer foam restricts motion of the aerogel from all sides of the aerogel or all sides except one.
Preferably, the polymer foam holds the aerogel immobile relative to the foam by direct contact with the aerogel or by exerting pressure against the aerogel through an intervening material, e.g., a vapor barrier.
In one embodiment, the polymer foam directly contacts the aerogel.
In a particular embodiment, the composite material is prepared by foaming the polymer in a space with the aerogel to expand the polymer foam against the aerogel. The polymer foam may expand directly against the aerogel, i.e., to make direct contact with the aerogel, or may expand against an intervening material between the foam and the aerogel, to make an indirect association with the aerogel through the intervening material and exert pressure against the aerogel.
Creating a composite material where the foam exerts pressure against the aerogel and holds the aerogel immobile relative to the foam can occur by foaming the polymer in a space with the aerogel, or by forming the composite material by associating preformed foam with the aerogel.
In particular embodiments, the composite material is a uniform blend of the polymer foam and aerogel particles of 1 cm diameter or less. In other embodiments, it is a uniform blend of the polymer foam and aerogel particles of 1 mm diameter or less.
In particular embodiments, the composite material comprises two or more layers of the polymer foam containing one or more layers of aerogel. The one or more layers of aerogel may be an aerogel blanket. An aerogel blanket involves aerogel held together by fibers. SPACELOFT is an aerogel blanket available from Aspen Aerogel. In another embodiment, the one or more layers of aerogel are aerogel particles.
In the embodiments of composite material comprising two or more layers of the polymer foam containing one or more layers of aerogel, the two or more layers of polymer foam may further comprise aerogel particles dispersed therein, i.e., the foam layers may be a uniform blend of the polymer foam and aerogel particles of 1 cm diameter or less.
The composite materials may be used for storage of a cryogen, so in one embodiment, the composite material further comprises a cryogen adsorbed to the aerogel. As used herein, the term “cryogen” refers to a substance that is a gas at room temperature and has a boiling point at atmospheric pressure of about −143° C. (130 K) or below.
One embodiment of the invention provides a composite material comprising a polyimide foam containing an aerogel. The polyimide foam may be pure polyimide or a polyimide copolymer.
One embodiment of the invention provides a cryogen storage apparatus comprising: (a) a composite material comprising: (i) a polymer foam; containing and holding immobile relative to the polymer foam and (ii) an aerogel. The polymer foam forms one or more openings through the foam that allow fluid access to the aerogel; and the aerogel provides a storage medium for a cryogen.
If the polymer foam is open-cell, cryogen can pass through the foam to access the aerogel, and the polymer foam can completely enclose the aerogel. If the polymer foam is substantially closed-cell, the foam may enclose the aerogel and prevent cryogen access to the aerogel. If that is the case, one or more macroscopic holes or passageways through the foam can be provided to allow cryogen access to the aerogel. Sealing the cryogen, such as with a closed-cell foam, can be useful to slow and control cryogen loss from the aerogel. The same can be accomplished with a vapor barrier that is separate from the polymer foam. For instance a vapor barrier, e.g., a thin plastic sheet, can be placed between the foam and the aerogel in the composite material, or surrounding the composite material. To allow addition or release of cryogen from the aerogel, the vapor barrier has to have one or more openings. If no release is desired, a vapor barrier outside of the composite material can be added after loading cryogen on the composite material to completely enclose the composite material.
Because of greater access of fluid to the cryogen when the composite materials contain open-cell foams instead of closed-cell foams, the composites with open-cell foams often have a higher storage capacity for cryogen. Composites with closed-cell foams can equal the storage capacity of composites with open-cell foams if the architecture allows complete access of cryogen to the aerogel, which can be accomplished for instance, with macroscopic holes or passageways through the closed-cell foam to a layer of an aerogel blanket.
The cryogen storage capacity of the composites can also be increased by the use of lower-density aerogels than, for instance, Cabot NANOGEL. Lower-density aerogels have more space for cryogen storage.
An advantage of this cryogen storage apparatus is that the cryogen is nanosequestered in the aerogel, eliminating slosh of liquid cryogen. Another advantage is that if the apparatus is impacted, such as with shrapnel from a vehicle accident if the apparatus is a hydrogen or methane fuel tank, or with a micro-meteor impact if the apparatus is used in space travel, the foam may be torn, but would be expected to still maintain some structure. It thus would still hold the aerogel together and provide some insulation to the aerogel and cryogen stored in the aerogel, thereby preventing explosive release or rapid boil off of the cryogen, which could be hazardous, especially if the cryogen stored is a fuel such as hydrogen or methane.
In one embodiment of the cryogen storage apparatus, the polymer foam is at least 30% open-cell and the open cells of the foam provide the openings through the foam that allow fluid access to the cryogen.
In other embodiments, the polymer foam is at least 50% open-cell or at least 90% open-cell.
In another embodiment, the polymer foam forms macroscopic holes that are the openings through the foam that allow fluid access to the aerogel.
In one embodiment, the polymer foam forms a single macroscopic passageway that is the opening through the foam that allows fluid access to the aerogel.
In one embodiment, the aerogel is particles of less than 1 cm or less than 1 mm diameter dispersed in the polymer foam.
In one embodiment, the polymer foam and the apparatus are flame resistant.
In one embodiment of the cryogen storage apparatus, the polymer foam holds the aerogel immobile relative to the polymer foam by direct contact with the aerogel.
In another embodiment, the composite material further comprises an intervening material between the polymer foam and the aerogel and the polymer foam holds the aerogel immobile relative to the polymer foam by exerting pressure against the aerogel through the intervening material. The intervening material may be, for instance, a vapor barrier. A vapor barrier will slow and control loss of cryogen (boil off) from the aerogel. But a vapor barrier will have to have at least one opening to allow access of the cryogen to the aerogel for storage.
In another embodiment, the cryogen storage apparatus further comprises a vapor barrier partially or fully enclosing the composite material. If the vapor barrier fully encloses the composite material and removal of the cryogen from the apparatus is desired, the vapor barrier must be removable or openable to allow removing cryogen from the composite material.
In one embodiment, the apparatus is adapted to store a cryogen in the aerogel to cool a space surrounding the apparatus. In a more specific embodiment of this cooling apparatus, the apparatus is adapted to release stored cryogen at a controlled rate.
The composite material with open-cell foam may be encapsulated by a shrink wrap gas-impermeable material that is perforated with small holes. This structure can help to allow slow release of the cryogen at a controlled rate. The holes in the vapor barrier can be any size. In one embodiment they are smaller than the pores of the open-cell foam of the composite.
The polymer foam of composite materials of the cryogen storage apparatus may be any suitable polymer. In one embodiment, it is a polysiloxane, a polyurethane, or a polyimide. In one embodiment, it is a polyolefin, a polystyrene, a polyester, a polyamide, a polyether, a polyurethane, an acrylic polymer, a polyimide, a polyurea, a vinyl polymer, a polysiloxane, a polysulfide, a polycarbonate, a liquid crystal polymer, or a copolymer or mixture thereof.
Refrigerated shipping containers and boxes typically use styrofoam boxes inside cardboard boxes to ship everything from foods to flowers to biological specimens to pharmaceuticals. Many of the shipped items, including pharmaceuticals, are very expensive. Some materials require very narrow bands of temperature for more than 24 hours. The refrigerant used in current shipping is typically dry ice. Problems with these packages can include 1) non-uniform temperatures, 2) an inability to achieve the desired temperature with dry ice, and 3) too short a duration of the cold temperature, i.e., too much dry ice may be needed to keep it from completely subliming during transit. The composites can provide improved solutions to these problems. Shipping containers/boxes can be designed to take advantage of the more uniform and gradual dissipation of the refrigeration provided by the new composite when loaded with a cryogen such as liquid nitrogen.
The invention also provides articles of manufacture comprising a composite material of the invention.
In specific embodiments, the article is adapted for use at temperatures below −195° C. (78 K).
In specific embodiments, the article is adapted for use at temperatures above 200° C. (473 K).
In specific embodiments, the article is adapted for use at temperatures below −195° C. (78 K) and at temperatures above 200° C. (473 K).
In a particular embodiment, the article is a storage vessel for a cryogen adsorbed to the aerogel.
In other specific embodiments, the article is a structural member of a building, machine, or aerospace or maritime vessel.
In other specific embodiments, the article is an insulation panel of a building, machine, or aerospace or maritime vessel.
Another embodiment of the invention provides a method of insulating a location from sound involving interposing between the location and a source of sound a composite material of the invention.
The invention will now be illustrated with the following examples. The examples are intended to illustrate the invention but not limit its scope.
EXAMPLES
TEEK polyimide foams can be prepared as described in U.S. Pat. Nos. 6,133,330 and 6,180,746. This example uses TEEK H.
Friable Balloon Fabrication.
A salt-like foam precursor is synthesized by mixing monomer reactants of a diamine with a foaming agent (tetrahydrofuran) in methanol at room temperature. The diamine (3,4′-oxydianiline (ODA), 227 g—1.1 moles) is dispersed in a mixture of tetrahydrofuran (THF—1120 g) and 280 g of methanol (MeOH) at room temperature. The mixture is stirred. To the stirring 3,4′-ODA solution, a dianhydride (e.g. 4,4′-oxydiphthalic anhydride (ODPA), 176 g—0.57 moles) is added gradually at 15° C. to yield a homogenous solution. Solid contents and viscosity of the resulting solution and 30% (w/w) and 0.2 poise, respectively. The solution is then charged into a stainless-steel vat and treated at 70° C. for 14 hours in order to evaporate the solvent (THF and MeOH). The resulting material is cooled and crushed into a fine powder (2 to 500 microns). The polyimide precursor solid residuum is then treated for an additional amount of time (0 to 300 minutes) at 80° C. to further reduce the residual solvent to about 1-10% (w/w) depending on the final foam density desired. Residual amounts of THF are determined by measuring proton NMR spectra of the powders. The polyimide precursor powders are further treated at 100° C. to expand the powders without thermal imidization so that the apparent density of the precursor is decreased without thermal imidization and friable balloons resulted.
Friable Balloon Foaming Process.
The process of foaming the friable balloons into a solid neat piece of foam or foam filled with honeycomb was accomplished by closed-mold foaming technique. The mold may optionally contain a piece of honeycomb core. The top and bottom of the mold were graphite plates. In order to obtain a specific density of foam, a back calculation is utilized. The desired density was multiplied by the mold volume and a specific weight is obtained. To this weight an additional 20% is added to account for solvent removal and water formation during precursor imidization. Two metal heat plates are placed in contact with the top and bottom surfaces of the mold.
A cure cycle in a convection oven is used to fully imidize the friable balloons and form a well-consolidated piece of foam. The mold containing friable balloons is placed in the oven with the metal heating plates above and below the mold. The mold is restrained with weight on the top surface provided by the top metal heating plate. The oven temperature is raised to 250° C. from room temperature and then held for 1 hour. Then the temperature is raised again to 300° C. and held for 1 hour more. Then the oven is cooled to room temperature and the mold is removed.
Closed-Cell Content Testing.
Closed-cell content was measured according to ASTM D-6226 utilizing a Quantachrome UltraFoam 1000. Closed-cell measurements are determined by obtaining the open-cell content from Boyle's Law. Boyle's Law states that the volume of a gas at constant temperature is inversely proportional to its pressure (V=1/P). Therefore, if a known volume is pressurized in a contained chamber, the decrease in pressure can be correlated to the actual volume and simple mathematics allows the open-cell content to be determined. The closed-cell content equals 1 minus open-cell content.
Example 1
TEEK Foam-Aerogel Bead Composite
Seven grams of NANOGEL aerogel beads (Cabot Corporation) (nominal 1 mm beads) and 28 grams of TEEK friable balloons were placed into a container and shaken continuously for 1 minute until a homogenous mixture was obtained. The entire contents of the container, 35 grams of the mixture containing 20% aerogel beads and 80% TEEK friable balloons, were transferred to a 0.1524 meter by 0.1524 meter by 0.0318 meter stainless steel mold and covered with a porous graphite plate. The mold was then placed in a convection oven and the temperature was raised to 200° C. and held for 2 hours. Once done, the temperature was reduced to ambient and the mold was removed from the oven. The resultant foam composite weighed 30.56 grams with a density of 0.04138 g/cm 3 .
Example 2
TEEK with Aerogel Blanket Layer
A single piece of SPACELOFT aerogel blanket (Aspen Aerogel) (6 mm thick) was cut into a 0.1016 meter square. Thirty grams of TEEK friable balloons were weighed out. Fifteen grams of the TEEK friable balloons were poured into the bottom of a 0.1524 meter by 0.1524 meter by 0.0318 meter stainless steel mold and was shaken to disburse the balloons evenly across the mold surface. The aerogel blanket was then placed in the center of the mold and the remaining 15 grams of TEEK friable balloons were poured over the blanket. A porous graphite plate was placed over the mold and then the entire mold assembly was placed into a convection oven. The temperature was raised to 200° C. and held for 2 hours. Once done, the temperature was reduced to ambient and the mold was removed from the oven. The resultant foam composite weighed 30.41 grams with a density of 0.0412 g/cm 3 .
Example 3
TEEK with Diagonal Strips of Aerogel Blanket
SPACELOFT aerogel blanket was cut into strips 14 cm by 3 cm and inserted into a mold between layers of TEEK friable balloons at a 45 degree angle in a square mold as in Example 2. The strips of SPACELOFT were evenly spaced with some space between strips.
Example 4
TEEK Foam-Aerogel Bead PITA
14.54 grams of TEEK friable balloons were poured into a 0.1524 meter by 0.1524 meter by 0.0318 stainless steel mold to form the bottom layer. A structure was then inserted to keep aerogel filler away from the edge of the mold. The structure in one case is a square-shaped mold and another case is a mold with 4.76-mm diameter hexagonal internal chambers (honeycomb reinforcement). The structure was composed of aluminum. 6.05 grams of NANOGEL were poured into the structure to form a middle aerogel layer. The square mold structure was then removed; the honeycomb reinforcement when used was not removed and became part of the composite material. 14.53 grams of TEEK friable balloons are then poured around the edges and on top to form the top layer. The mold was then placed in a convection oven with a porous graphite top to allow solvent release, at a temperature of 250° C. for 1 hour and then 300° C. for 1 more hour.
Comparative Example 5
TEEK Foam
Thirty-five grams of TEEK friable balloons were transferred to a 0.1524 meter by 0.1524 meter by 0.0318 meter stainless steel mold and covered with a porous graphite plate. The mold was then placed in a convection oven and the temperature was raised to 200° C. and held for 2 hours. Once done, the temperature was reduced to ambient and the mold was removed from the oven. The resultant foam composite weighed 30.23 grams with a density of 0.0409 g/cm 3 .
Example 6
Thermal Conductivity and Density of the Composite Materials
Thermal conductivity of the samples was measured with a Netzsch NANOFLASH (Netzsch Instruments, Inc., Burlington, Mass.). The aerogel materials have a higher density in general than the foam, so a higher aerogel content tends to produce a higher density of the materials. But the density of the foam component can be modified to adjust the density of the composite material.
Table 1 shows density and thermal conductivity and thermal resistance of several samples.
TABLE 1
Thermal
Thermal
Density
Conductivity
Resistance
Sample - Description
(kg/m 3 )
(k) (mW/m · K)
(ft 2 · ° F. · h/Btu)
BX-265, A0 (Baseline)
36.923
18.59
7.81809
LARC-N1 (TEEK-aerogel homogeneous
40.733
31.716
5.63038
composite containing 10% aerogel
beads)
LARC-N2 (TEEK-aerogel homogeneous
41.377
30.972
5.77795
composite containing 20% aerogel
beads.)
LARC-N3 (Single layer aerogel blanket
41.173
25.908
7.00954
in TEEK)
LARC-N4 (Single layer aerogel blanket
44.059
25.52
7.08582
in TEEK)
LARC-N5 (Double layer aerogel blanket
48.284
21.803
8.33115
in TEEK)
LARC-N6 (Diagonal strips of aerogel
40.68
31.019
5.87709
blanket in TEEK)
LARC-N7 (Horizontal strips of aerogel
40.793
29.91
6.00441
blanket in TEEK)
LARC-N8 (Vertical strips of aerogel
40.566
31.559
5.72727
blanket in TEEK)
TEEK-aerogel homogeneous composite
41.672
32.217
5.637
(10% aerogel beads)
TEEK-aerogel homogeneous composite
46.256
30.822
5.886
(20% aerogel beads)
TEEK 100%
40.924
33.234
5.480883
Table 1 illustrates the significant decrease in thermal conductivity (increase in thermal resistance and better thermal insulation) of the composite materials compared to 100% TEEK foam. In Table 1, a rigid closed-cell polyurethane foam, STEPANFOAM BX-265, is included as a standard reference. The BX-265 displays good thermal insulation ability, but it degrades chemically and mechanically with time. The BX-265 does not have good acoustical properties and has limited upper temperature usage.
Table 2 includes reference thermal conductivity data for the fillers—aerogel beads and blankets—as well as TEEK and composites. As shown in Table 1, the composites have significantly lower thermal conductivity than the base foam. The base aerogel materials have lower thermal conductivity, but TEEK adds significant structural properties.
TABLE 2
Thermal
Thermal
Density
Conductivity (k)
Resistance
Material
(kg/m 3 )
(mW/m · K)
(ft 2 · ° F. · h/Btu)
Cabot Aerogel Beads
90
18
6.475
Aspen Aerogel SPACELOFT Composite
94.39
13.82
10.434
Blanket, One layer
Aspen Aerogel SPACELOFT, 2 layers
94.39
13.76
10.48
TEEK 100%
39.49
33.537
4.3
PITA sandwich composite with layer of
69.23
23.497
6.137
aerogel beads in TEEK (18% aerogel content)
PITA sandwich composite with double layer
77.04
29.833
4.816
of aerogel (TEEK-aerogel-TEEK-aerogel-
TEEK) (22% total aerogel content)
TEEK 18% Aerogel homogeneous composite
67.09
29.301
4.932
TEEK 16% Aerogel homogeneous composite
77.8
29.973
4.837
TEEK 100%
69.81
34.51
4.234
The thermal conductivity and density of TEEK-aerogel PITA composites prepared with and without a honeycomb to separate aerogel into compartments are shown in Table 3. BX-250 is a polyurethane foam included for comparison.
TABLE 3
Thermal conductivity and density
of PITA-type TEEK composites.
Thermal
Aerogel
conductiv-
Density
content
ity (k)
Material
PITA type
(g/cm3)
w/w (%)
(mW/m-K)
TEEK-1-42
single
0.0671
18.0
29.3010
TEEK-1-40
double
0.0770
22.0
29.8330
TEEK-1-43
single
0.778
17.0
29.9730
TEEK-1-36
single-honeycomb
0.1092
11.0
38.4951
TEEK-1-37
single-honeycomb
0.1339
18.5
38.6690
TEEK-1-39
single-honeycomb
0.0583
13.0
39.074
BX-250
N/A
0.0241
0.0
18.97
The data show that the PITAs with the honeycomb reinforcement have higher thermal conductivity (lower thermal resistance and less thermal insulation ability) than PITAs prepared without the honeycomb reinforcement.
Thermal conductivity and density of composite samples that are a homogeneous mixture of TEEK and aerogel, aerogel beads in a PITA style pocket in TEEK, or a TEEK-aerogel blanket sandwich composite are shown in Table 4. The density of the foams varies between different samples.
TABLE 4
Polyimide foam composite thermal conductivity and density data.
Thermal
Conductiv-
Density
ity (k)
Material
lb/ft 3
mW/m-K
TEEK control
2.49
32.98
TEEK control
2.55
33.23
TEEK control
6.11
36.10
TEEK control
2.54
32.38
TEEK control
1.76
31.24
TEEK 10% aerogel w/w
2.60
32.22
TEEK 10% aerogel w/w
6.03
33.76
TEEK 10% aerogel w/w
2.33
31.97
TEEK 20% aerogel w/w
2.89
30.82
TEEK 20% aerogel w/w
6.18
31.32
TEEK 20% aerogel w/w
2.38
30.82
TEEK 25% aerogel w/w
2.97
30.17
TEEK 25% aerogel w/w
5.98
29.69
TEEK 25% aerogel w/w
2.43
30.63
TEEK 30% aerogel w/w
2.99
29.48
TEEK 30% aerogel w/w
2.45
29.85
TEEK 40% aerogel w/w
3.38
28.09
TEEK 40% aerogel w/w
2.52
29.20
TEEK PITA with pocket of aerogel beads
2.91
26.48
TEEK aerogel blanket 1 layer
6.17
26.18
TEEK aerogel blanket 2 layer
6.12
21.04
TEEK aerogel blanket diagonal strips (9)
5.99
33.20
Aerogel blanket 1 layer in TEEK-10%
2.88
24.83
aerogel homogeneous composite.
Aerogel blanket 1 layer in TEEK-30%
3.45
24.22
aerogel homogeneous composite.
Aerogel blanket diagonal strips (9) in TEEK-
2.34
27.00
30% aerogel homogeneous composite.
The density of the TEEK in the composite materials of Table 4 varied. This is shown, and the effect of the variance is shown, graphically in FIG. 1 . FIG. 1 shows that as more aerogel is included in the composite, the k-value decreases. Concentrating the aerogel in one area in the PITA configuration or with an aerogel blanket sandwiched between layers of TEEK decreases the thermal conductivity more than dispersing aerogel particles homogeneously in the foam. The composite with two layers of aerogel blanket had the lowest k-value. In the composites with two layers of aerogel blanket, the two layers of aerogel blanket are separated by an additional layer of TEEK (i.e., the structure is TEEK-aerogel-TEEK-aerogel-TEEK). The overall dimensions remain the same.
FIG. 2 shows the averaged thermal conductivity and density of homogeneous composites with 0-40% (w/w) aerogel beads. The figure shows the clear trends that the higher the aerogel content, the higher the density the composite materials tends to be and the lower the thermal conductivity (k-value).
The density of TEEK foam can be modulated, so that the density of the composite materials is kept constant as aerogel is added. A comparison of samples with 0-25% aerogel but with a constant density near 6 lbs/ft 3 is shown in FIG. 3 . In this figure, the composite with 25% aerogel has a thermal conductivity approximately 18% lower than the pure TEEK foam.
Example 7
Cryogen Storage in Foam-Aerogel Composites
Cryogenic liquids such as liquid nitrogen adsorb to the surfaces in aerogel and also, to a lesser extent, to the surfaces of foam. Aerogel beads and blankets were soaked in liquid nitrogen, then bulk liquid was drained and the materials were placed on a balance to monitor weight loss as adsorbed nitrogen in the materials desorbs and diffuses out. Seventy-eight grams of NANOGEL aerogel beads adsorbed approximately 370 grams N 2 . Forty-one grams of SPACELOFT aerogel blanket adsorbed approximately 145 grams N 2 . So aerogel can adsorb many times its own weight of a cryogen.
The boil-off rate of adsorbed N 2 from aerogel blanket and beads is shown in FIGS. 4A and 4B , respectively.
Liquid N 2 can also adsorb to some extent to TEEK foam. Storage of liquid N 2 in five TEEK foam samples prepared from friable balloons is shown in Table 5.
TABLE 5
Liquid N 2 storage in TEEK foams.
Sample
N109
N110
N115
N116
N136
material
TEEK control
TEEK control
TEEK control
TEEK control
TEEK control
density (lb/ft3)
2.49
2.55
6.11
2.54
1.76
k-value (mW/m-K)
32.98
33.23
36.10
32.38
31.24
Cryo-Storage (min)
LN2 (g)
LN2 (g)
LN2 (g)
LN2 (g)
LN2 (g)
0
42.176
13.430
0.188
50.369
49.864
1
32.327
10.311
0.187
41.597
38.930
2
27.576
8.222
0.199
34.865
30.159
3
23.327
5.451
0.204
29.736
24.177
4
19.801
4.922
0.204
25.381
19.517
5
16.831
3.681
0.198
21.680
15.665
6
14.184
2.697
0.190
18.453
12.364
7
11.859
1.958
0.179
15.627
9.668
8
9.826
1.310
0.167
13.118
7.430
9
7.990
0.917
0.154
10.952
5.684
10
6.366
0.613
0.141
9.024
4.305
11
4.996
0.418
0.129
7.361
3.234
12
3.796
0.311
0.116
5.896
2.369
13
2.826
0.281
0.105
4.683
1.698
14
2.022
0.263
0.096
3.636
1.204
15
1.288
0.250
0.087
2.790
0.830
16
0.760
0.239
0.080
2.052
0.620
17
0.327
0.226
0.073
1.485
0.544
18
0.032
0.217
0.067
1.064
0.513
19
−0.158
0.207
0.061
0.728
0.489
20
−0.227
0.197
0.056
0.529
0.468
Table 5 shows that cryogen adsorption to the TEEK foams varied between samples. This is due to the closed-cell content of the foam and other structural traits of the foams. A 100% closed-cell foam would not be expected to absorb cryogen because the cryogen would not have access to the interior of the foam. The highest density foam sample tested, N115, in Table 5 absorbed almost no N 2 . N110 also absorbed less than the others. The other foams absorbed approximately 1.4 times their weight in N 2 .
The TEEK foam-aerogel composite materials also adsorb N 2 . Adsorption of N 2 and boil-off of the N 2 in some TEEK foam-aerogel composite materials is shown in Table 6.
TABLE 6
Liquid N 2 storage in TEEK foam-aerogel composites.
Sample
N111
N130
N134
N117
material
TEEK 30%
TEEK 30%
TEEK 30% aero
TEEK aeroblanket
aerogel w/w
aero w/w
aeroblanket 1 layer
1 layer
density (lb/ft3)
2.99
2.45
3.45
6.17
k-value (mW/m-K)
29.48
29.85
24.22
26.18
Cryo-Storage (min)
LN2 (g)
LN2 (g)
LN2 (g)
LN2 (g)
0
86.567
88.335
140.862
0.431
1
73.262
78.470
124.802
0.139
2
65.465
70.778
115.403
0.140
3
59.735
64.511
108.132
0.135
4
54.220
59.142
102.107
0.123
5
49.862
54.365
97.009
0.110
6
45.965
50.025
92.459
0.094
7
42.591
46.010
88.325
0.076
8
39.555
42.323
84.518
0.065
9
36.782
38.880
81.062
0.054
10
34.283
35.763
77.722
0.047
11
31.934
32.835
74.742
0.039
12
29.652
30.097
71.828
0.033
13
27.650
27.582
69.107
0.027
14
25.834
25.242
66.542
0.022
15
23.992
23.006
64.041
0.016
16
22.215
20.951
61.693
0.012
17
20.604
19.041
59.490
0.009
18
19.084
17.249
57.382
0.005
19
17.724
15.567
55.344
0.001
20
16.292
13.992
53.410
−0.002
In Table 6, N111 and N130 are TEEK foam-aerogel particle homogeneous mixtures. N134 is a sandwich of 30% aerogel homogeneous TEEK foam-aerogel sandwiched around an aerogel blanket. N117 is a sandwich with 100% TEEK foam surrounding an aerogel blanket. Each of these samples is a 6 inch×6 inch×1.25 inch (0.1524 meter by 0.1524 meter by 0.0318 meter) block. N134 and N117 have a 5×5 inch×6 mm (127 mm×127 mm×6 mm) aerogel blanket in the center of the block.
The composite samples N111, N130, and N134 adsorbed substantially more N2 than pure TEEK foams do, due to adsorption of the cryogen in pores of the aerogel. N117 is a sample with higher-density foam, and like the high-density foam sample N115 in Table 5, it adsorbed almost no cryogen. In this case the foam structure appears to seal the aerogel and prevent the flow of cryogen into and out of the aerogel. The other foam-aerogel composite samples of Table 6 also adsorbed substantially less nitrogen than they would have if 100% of their volume were occupied by adsorbed nitrogen. This indicates that the foam structure of these as well seals a significant fraction of the aerogel from cryogen. The foams in these composite were TEEK foams prepared from friable balloons. These have a closed-cell content of about 30-80%. A more open-cell foam is expected to allow greater access of cryogen to the aerogel and thereby allow storage of more cryogen.
Although specific embodiments of the present invention have been illustrated and described in this specification, it will be appreciated by those of ordinary skill in the art that any arrangement that is calculated to achieve the same purpose may be substituted for the embodiments shown. This application is intended to cover adaptations or variations of the present invention that come within the scope of this disclosure.
All patents, patent documents, and other references cited are incorporated herein by reference. | The invention involves composite materials containing a polymer foam and an aerogel. The composite materials have improved thermal insulation ability, good acoustic insulation, and excellent physical mechanical properties. The composite materials can be used, for instance, for heat and acoustic insulation on aircraft, spacecraft, and maritime ships in place of currently used foam panels and other foam products. The materials of the invention can also be used in building construction with their combination of light weight, strength, elasticity, ability to be formed into desired shapes, and superior thermal and acoustic insulation power. The materials have also been found to have utility for storage of cryogens. A cryogenic liquid or gas, such as N 2 or H 2 , adsorbs to the surfaces in aerogel particles. Thus, another embodiment of the invention provides a storage vessel for a cryogen. | 1 |
STATEMENT OF RELATED APPLICATION
This application claims the benefit of U.S. Provisional Application 60/564,904, filed Apr. 23, 2004, which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
This invention generally pertains to wavelength division multiplexed optical communication systems, and more particularly to a means to direct light in a flexible manner, including the articles and means to construct such a system.
BACKGROUND OF THE INVENTION
There has been significant commercial interest in multiple wavelength WDM systems in recent years, hereafter referred to as Dense Wavelength Division Multiplexing (DWDM) systems. These systems leverage the capability of a single optical fiber to carry multiple wavelengths of light, a technique that effectively multiplies the bandwidth capacity of a given fiber by the number of wavelengths that can be transmitted. The demand for higher bandwidth communication systems has been driven by large increases in information flow driven by the Internet and other data traffic. In addition, the invention of Erbium Doped Fiber Amplifiers (EDFA) to amplify the power levels of many wavelengths in a single amplifier has further increased the application space of this technology because the amplification cost per wavelength for an EDFA is very low compared to the Optical-to-Electrical-to-Optical (OEO) regeneration that would otherwise be needed, hence it is much cheaper to send large numbers of wavelengths over large distances in a single fiber than it would be to send individual wavelengths over separate fibers. This economic justification has led to the transmission of large amounts of bandwidth in multiple wavelengths over a single fiber, and in turn has driven the need to flexibly route those wavelengths at the wavelength layer to avoid bandwidth scaling issues with electrical based switching (cost/size/heat dissipation/upgradability) as well as the expense of OEO regeneration that electrical switching requires. The availability of cost-effective signal amplification from the EDFA has in part supported increased functionality at the wavelength layer by providing a reasonable insertion loss budget for new subsystems to obtain this functionality.
The earliest wavelength routing devices preceded the EDFA, and generally leveraged wavelength dependent evanescent coupling between multiple waveguides, or the wavelength-dependent transmission of a dielectric Thin Film Filter (TFF) to passively route light along multiple paths in a wavelength-dependent manner. In general these devices have low cost and low insertion loss, however the wavelength-dependent routing configuration is static and the intrinsic device provides for no control or feedback of the optical signals that flow through it. These limitations have been overcome in modern communication systems by designing subsystems from these basic wavelength-dependent routing building blocks that integrate detectors for monitoring, Variable Optical Attenuators (VOAs) for power level control, and optical switches for changing the routing configuration. This integration can be in the form of discrete devices (or arrays of devices), integration on a Planar Lightwave Circuit (PLC), or a hybrid free-space Wavelength Selective Switch (WSS).
The WSS is the newest and perhaps the most scalable wavelength monitoring and signal control device because it operates on all wavelengths within a single free-space region, thus has a lower per wavelength cost for many wavelength devices. The functionality of the device is shown in 100 of FIG. 1 , where any wavelength on input 101 of the device can be routed via switches 104 to any output port 110 - 117 at a preset attenuation (or power level) determined by the settings of VOA 103 , where that routing is independent of the routing of the other wavelengths because the input demultiplexer 102 and output multiplexer array ( 105 ) create independent routing paths for each wavelength. This is essentially the most flexible wavelength routing device possible, and it is achieved with better performance (insertion loss, filtering characteristics) than available from discrete components or integrated PLCs. Although this WSS technology is not yet mature, it seems quite likely that the premium performance and price of this technology will enable it to dominate signal control and monitoring applications in devices where flexible routing of many wavelengths is required.
At the present time, the segments of the communication network with economic justification for flexible routing of many wavelengths are the long haul, regional and/or metro-core networks. In the metro edge and or access networks there are currently not many wavelengths at a given node, and the traffic pattern of the wavelengths present is almost exclusively hubbed, that is information collected from all the edge nodes on a ring are backhauled to a single common hub node. The most efficient optical layer protection for this well-defined traffic pattern is a simple dedicated (1+1) protection scheme and essentially one end of every service is a-priori known to be the hub node. For these reasons, the per-wavelength routing flexibility of a WSS is not nearly as valuable as in other parts of the network where mesh traffic patterns prevail. In addition, this edge portion of the network is shared by the fewest customers, and hence requires the lowest cost structure. Therefore it is likely that even though the WSS is more cost-effective than the other technology alternatives with equivalent functionality, it is likely too expensive to use at the edge of the network where the flexibility it provides may not add sufficient value.
While network edge components may not require the extraordinary flexibility of a WSS, it still can benefit from added flexibility. The edge of the current network is dominated by the Multi-Service Provisioning Platform (MSPP), which aggregate multiple clients through an electrical switch fabric, and transmit a single wavelength line signal to the hub node (typically along two diverse paths). However as the bandwidth for a single customer approaches the capacity of a single wavelength, the services provided would transition to “wavelength services”, and numerous wavelength services might be required even within a single building that houses multiple businesses. Examples of these wavelength services are the full (non rate-limited) bandwidth services of Gigabit Ethernet (GbE) and 10 Gigabit Ethernet (10 GbE). This evolution of the network edge dilutes the value of MSPP electrical aggregation of many lower bandwidth signals into a single wavelength, while enhancing the value of DWDM networks that carry multiple wavelengths to a single access node. This type of network will typically be constructed from rings to provide signal protection through diverse path routing, and will have a hubbed traffic pattern such that traffic from all edge nodes is backhauled to the hub node. Today static TFF couplers largely service the DWDM Optical Add-Drop Multiplexing (OADM) at an edge node in this part of the network. These filters route (demultiplex) either a single wavelength or a band of wavelengths to a different output than the remaining DWDM wavelengths. Installation of new TFF filters breaks the optical path passing through a node, which is at the very least undesirable, and for many carriers unacceptable if signals from other nodes are interrupted. For this reason this part of the network frequently uses a TFF OADM that drop bands or groups of wavelengths from the express path. This approach has the benefit that only a single, relatively inexpensive and low loss TFF is needed at installation for the wavelengths passing through the node, thus adding additional drop wavelengths through that existing banded filter do not interrupt, or “hit” the existing services. Such a service addition does require installation of additional demultiplexing filters for each drop wavelength, however this installation is “hitless” because it does not impact the existing services.
There remains room for improvements of OADM flexibility in access applications even with the aforementioned benefits of TFF OADM. The need for improvement primarily stems from three limitations. The first is that for hitless upgrades of additional wavelengths the demands for each node need to be preplanned to correctly install the required TFF in the express path (through) at each node. This preplanning is not only time consuming, but also results in unused, stranded system capacity when capacity at that node does not materialize to meet the projected demand. The second limitation is the concatenation of multiple banded TFFs and individual demultiplexing drop filters is a time-consuming, manually intensive process that requires skilled craftsmen. The final limitation is this complex arrangement of filters can result in significant amounts of loss, including differential loss for different wavelengths. This loss variation results in a system reach that is wavelength-specific, implying wavelength-dependent engineering rules for the system that will be custom for every configuration. To mitigate this impact, systems typically install multiple individual attenuators on each transmitter to provide the required transmission performance for each channel. These latter two problems prevent the equivalent automation of signal routing in the optical layer as has always been provided in the electrical layer. This combination of non-automated, manual, and skill-intensive configuration procedures creates a barrier to fast deployment of DWDM at the edge of the network, and is in general an impediment to rapid deployment of cost-effective, high bandwidth services at the edge of the network.
Accordingly, it would be useful for a communication system to be cost optimized for the edge of the network while providing more automated line-side provisioning that does not require pre-planning while minimizing the probability that unused bandwidth will be stranded at the edge nodes. This application will describe such a system, including unique components and subsystems required for such a system.
SUMMARY OF THE INVENTION
In accordance with the present invention, an optical wavelength routing device is provided, which utilizes a free space optical beam propagating therethrough. The device includes at least one optical fiber input, at least one optical fiber output, an optical element having an actuator with at least one tilt axis and a diffraction element having a surface thereon. The device also includes an optical beam-splitting element having spatially varying optical properties. An optical beam transfer arrangement is positioned between the optical element and the diffraction element such that tilt actuation of the optical element elicits a proportional change in an angle of incidence of the optical beam onto the diffraction element, wherein the center of rotation for the angular change is the surface of the diffraction element. Optical routing between the fiber input and the fiber output can be configured by the positioning of the optical element.
In accordance with one aspect of the invention, the optical beam actuator has two tilt axes.
In accordance with another aspect of the invention, the two tilt axes enable substantially independent control of both a center wavelength and a drop bandwidth of the optical beam diverted from the primary output port
In accordance with another aspect of the invention, the two tilt axes enable substantially independent control of both a center wavelength and power level of routed wavelengths.
In accordance with another aspect of the invention, the optical beam transfer arrangement is a lens-based telescope.
In accordance with another aspect of the invention, at least 2 optical fiber outputs are provided.
In accordance with another aspect of the invention, the optical element is a 2 axis MEMs tilt mirror.
In accordance with another aspect of the invention, the diffraction element is a reflective diffraction grating.
In accordance with another aspect of the invention, the diffraction element is a transmissive diffraction grating.
In accordance with another aspect of the invention, the optical beam-splitting element comprises a flat mirror surface and a beamsplitting region with stepwise segmented width variation in an axis perpendicular to grooves of the diffraction grating to perform spectrally selective routing.
In accordance with another aspect of the invention, the stepwise segmented regions have a smoothed transition between them.
In accordance with another aspect of the invention, the optical beam-splitting element comprises a flat mirror surface and at least two separate beamsplitting regions of optical reflection and/or transmission along an axis that is perpendicular to grooves in the diffraction grating to perform spectrally selective signal routing.
In accordance with another aspect of the invention, the optical beam-splitting element comprises a flat mirror with spatially varying reflectivity to perform spectrally selective routing and to impart a desired wavelength dependent loss.
In accordance with another aspect of the invention, the optical beam splitting element with spatially varying optical properties has dithered optical transition regions to reduce PDL of split optical beams.
In accordance with another aspect of the invention, an optical wavelength routing device is provided, which utilizes a free space optical beam propagating therethrough. The device includes at least one optical fiber input, at least two optical fiber outputs, an optical element having an actuator with two tilt axes, a diffraction element, and an optical beam-splitting element having spatially varying optical properties. The spectral transmission properties are configurable by selective positioning of the actuator about the tilt axes.
In accordance with another aspect of the invention, a coupling arrangement is provided on at least one of the multiwavelength output ports that use a fiber optic passive splitter to direct substantially identical copies of that output signal into separate paths for subsequent demultiplexing.
In accordance with another aspect of the invention, a single channel optical bandpass filter is coupled to one or more of the optical splitter output ports to enable transmission of the single channel.
In accordance with another aspect of the invention, light from at least one of the multiwavelength output ports is coupled into a cyclical demultiplexer that separates any contiguous drop bandwidth into individual channels.
In accordance with another aspect of the invention, the cyclical demultiplexer is based on arrayed waveguide technology.
In accordance with another aspect of the invention, the cyclical demultiplexer is based on cascaded periodic filter technology.
In accordance with another aspect of the invention, a DWDM optical communication transmission system is provided. The system includes a plurality of nodes interconnected by an optical transmission path and an optical wavelength routing device. The optical wavelength routing device includes at least one optical fiber input, at least two optical fiber outputs, an optical element having an actuator with two tilt axes, a diffraction element, and an optical beam-splitting element having spatially varying optical properties. The spectral transmission properties are configurable by selective positioning of the actuator about the tilt axis. One of the fiber outputs selectively routes wavelengths along an express path through a node to a subsequent node, and the other of the fiber outputs routes drop optical traffic at that node.
In accordance with another aspect of the invention, the plurality of nodes are arranged in a ring topology with a hub traffic pattern.
In accordance with another aspect of the invention, the plurality of nodes are arranged in a ring topology with a mesh traffic pattern, wherein at least two of the nodes on the ring have independent drop access to any wavelength.
In accordance with another aspect of the invention, a wavelength selection algorithm is provided for a tunable optical wavelength device with contiguous bandwidth restriction that, upon request, provides an advantageous bandwidth expansion wavelength depending on a least one of the following factors: unutilized bandwidth on either side of the existing dropband; capacity currently dropped at a node; capacity dropped at nodes in the adjacent nodes in spectrum space; and the number of nodes sharing bandwidth on the network.
In accordance with another aspect of the invention, a method is provided for variably adjusting the center wavelength and drop bandwidth of a 3 port tunable filter. The method includes the steps of: dispersing input wavelengths laterally across an optical arrangement oriented to reflect input wavelengths into a first output port; selectively positioning the dispersed wavelengths over an optical beamsplitting region of the optical arrangement that splits the portion of the optical beam impinging on the beamsplitting region and directs the split portion of the beam to a second output port; adjusting the position of the input wavelengths along a first axis to position the center wavelength on the beamsplitting region; and adjusting the position of the input wavelengths along a second axis perpendicular to the first axis to position the input wavelengths on a portion of the beamsplitting region that is wider or narrower depending on whether a wider or narrower bandwidth, respectively, is desired.
In accordance with another aspect of the invention, a hitless bandwidth tunability is provided on the first output during a change in wavelength configuration by further adjusting a position of the incident wavelengths along the second axis via the narrower beamsplitting region direction to a region of the optical arrangement that has no beamsplitter and adjusting the position of the incident wavelengths along the first axis to align a selected center wavelength adjacent to a narrowest portion of the beamsplitter region.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a functional diagram of a Wavelength Selective Switch, which can be achieved with different technologies that do not necessarily employ the same discrete elements.
FIG. 2 shows a configuration of a Wavelength Selective Switch based on a free space diffraction grating.
FIG. 3 shows one embodiment of a hitless tunable filter constructed in accordance with the present invention.
FIGS. 4A-4C show the positional dependence of the spectrally separated beam on the beamsplitter surface relative to the positioning of the tilt mirror depicted in FIG. 3 .
FIGS. 5A-5F show various embodiments of the retro-reflecting mirror.
FIG. 6 shows an alternative embodiment of the hitless tunable filter constructed in accordance with the present invention.
FIG. 7 shows a hubbed system architecture using a tunable hitless filter with dynamic drop bandwidth allocation.
FIGS. 8A-8C show a three port hitless tunable filter used in various OADM configurations.
FIGS. 9A and 9B show different view of one embodiment of a multiple input optical channel monitor constructed in accordance with the present invention.
FIGS. 10A and 10B show alternative embodiments of the channel monitor depicted in FIGS. 9A and 9B , which employ separate grating and tilt mirror elements.
FIG. 11 the input collimators of FIG. 10 arranged in a double pass configuration.
FIGS. 12A and B show the wavelength dependent loss resulting from varying reflectivity over different mirror surfaces.
DETAILED DESCRIPTION
In accordance with the present invention, a Hitless Tunable Filter (HTF) technology is provided to flexibly route optical signals. It provides wavelength-selective routing functions in a much simpler and lower cost structure than currently available from existing WSS technology. Although this simplification somewhat reduces the functionality relative to a WSS, it retains a significant level of flexibility that would make it a superior choice for cost-sensitive network applications as it can be provided at a fraction of the cost, with a significantly reduced insertion loss, and with low polarization sensitivity as is required for virtually all communication system applications.
There are multiple technology platforms which have been used to demonstrate the functionality of a WSS, including free space optics with a diffraction grating (see U.S. Pat. Nos. 5,960,133, 6,097,859), free space optics with thin film filters (U.S. Pat. No. 6,631,222), and integrated photonic lightwave circuits (C. R. Doerr, et al., Eight-wavelength add-drop filter with true reconfigurability IEEE Phot. Tech. Lett. Vol. 15, Issue 1, 138-140 (2003)). FIG. 2 shows an exemplary prior art WSS arrangement of the diffraction grating approach. In this arrangement incoming light from one of the collimators in the input collimator array 200 , and diffracts off a grating 210 , which spectrally separates the input signal into different wavelength components, which are then focused with cylindrical lens 230 onto switch array 240 . Switch array 240 has multiple tilting mirror elements, 241 , 242 , 243 , etc., and typically contains at least one for each wavelength. The individual mirrors can preferably tilt in two axes to retroreflect the incident beam along a path that is offset from the input beam but parallel and in the opposite direction. The individual mirrors can be controlled such that these retroreflected beams can be coupled into other collimators in the collimator array that serve as output ports. Detuning the beam alignment relative to the optimum position can also control the power coupled into the output ports. This arrangement effectively yields a switch with the capability to route any wavelength from the input to the output at an adjustable power level, where the routing of each wavelength is independent of the others. This enables reconfiguration of any drop wavelength without effecting the power or crosstalk of any other thru or drop wavelengths. This is often referred to as “hitless” reconfiguration, where for true hitless configuration, the reconfiguration not only would avoid disrupting the transmission along the other paths of the device, but in addition no undesired crosstalk will arise from other wavelengths being coupled into any of the existing output ports during mirror repositioning.
A two port tunable filter that uses fewer elements than a WSS is disclosed in U.S. Patent Application 2004/0136074. This device discloses a number of arrangements using a tiltable diffraction grating to provide a tunable wavelength filtered output, however as disclosed this device has several limitations which make the device unsuitable for the majority of optical communication system applications today. Specifically, this reference does not disclose an implementation with low cost, low Polarization Dependent Loss (PDL), low Insertion Loss (IL) and high reliability required for communication system applications. The reasons these desirable properties cannot be achieved simultaneously by the filter shown in this reference is because of the following limitations described in the specification thereof:
(a) Need to double pass to allow a low insertion loss coupling of a multiple band wavelength spectrum to a single mode fiber output port as stated in the last sentence of paragraph 66 (b) when double passing need to have a 2 axis tilting mechanism and the diffraction grating co-located to maintain efficient optical coupling when tilting the grating (para 80) (c) The only structures proposed that can simultaneously solve problems (a) and (b) with high reliability and low cost are the MEMs structures proposed in FIG. 17 . However all commercially available high diffraction efficiency, low PDL gratings require highly specialized fabrication structures that are not compatible with MEMs fabrication processes and cannot be readily embossed or replicated as proposed. The MEMs gratings used in laser and spectroscopic applications have strong polarization dependence and a single axis tilt rather than 2 axes.
Additional problems with the device shown in the reference that are overcome by the present invention include:
No description is provided of how to scale from the two port filter to a conventional OADM device that provides 3 ports (input, express output, and filtered add/drop) The concept and means to achieve hitless tunability is not described, and specifically how to reconfigure a conventional 3 port OADM to change drop capacity without disruption to any channels on the thru or drop paths. The disclosed alignment of grating grooves relative to incidence angle preclude operation at the Littrow incidence condition required for commercially available high efficiency, low PDL gratings. Does not provide a means for the output fiber to couple light from the different positions along the axis which has the spectral resolution (slit width) variation, thereby preventing the variable bandwidth feature of the optical transmissive filter discussed in connection with FIG. 9 of this application.
As will be seen below, the present invention overcomes these limitations of prior art by disclosing an optical telescopic arrangement that tilts a beam incident on a static grating about a “virtual pivot” point on the surface of the grating. This arrangement enables the virtual co-location of the 2 axis tilting mechanism and the diffraction grating while using off-the-shelf, 2 axis MEMs tilt mirrors as well as a high efficiency, low PDL grating that in its Littrow arrangement is also a standard part. When properly designed, this telescope can also provide beam expansion, which can be advantageous because the tilted beams can be small on the MEMs mirror to minimize mirror size, while the beams can be expanded on the diffraction grating where larger beams are desired to improve spectral resolution by illuminating more grating grooves. The present invention described below will leverage this concept to enable a low cost tunable filtering device with low IL, low PDL, multiple output ports and hitless reconfigurability in a compact, reliable device.
The arrangement of the present invention is shown in FIG. 3 . In this invention, the input beam enters through an input collimator 300 and diffracts off a grating that is fabricated on a 2-axis analog tilt gimbal, 310 . The diffraction off this grating is incident on aspheric lens 330 , which is separated by its focal distance from the grating diffraction point. In this position, the lens will parallelize (collimate) the beams diffracted at different angles, which in the plane perpendicular to the grating lines corresponds to the wavelengths that are diffracted at different angles. The collimated beam with spatially separated wavelengths are then reflected off mirror 340 , which reflects the beam, except for a small aperture in the center which allows a small wavelength range to be transmitted. The transmitted beam is then routed into drop collimator 350 for subsequent use in the system. The reflected beam passes back through the lens and grating, and is recollected at the input collimator. The input/output beams can be separated with a circulator, passive coupler, or by using a separate collimator (not shown). The output light can be coupled into a separate collimator located above the input collimator by tilting the surface normal of mirror 340 out of the page to reflect the output beam into the added output collimator. It should be noted that the polarization dependence of the grating diffraction efficiency is ideally very low to minimize the Polarization Dependent Loss (PDL) of the entire device. Gratings with low PDL are available commercially, however this PDL might be improved even further by adding a quarter waveplate 320 between the first and second pass of this device to cancel any remaining PDL. Low PDL could also be obtained with a high PDL grating via a polarization diversity approach where two orthogonal input polarizations are split, and one rotated to align with the other so they can pass through the device in the same polarization before rotation and recombination brings the two polarizations back together at the output.
FIG. 4 shows how the optical spectrum of the input beam moves along the surface of the mirror 340 as the spectrum changes with grating tilt. Tilt of the grating along the axis parallel to the grooves will change the diffraction angle of different wavelengths, which in turn changes the lateral position where different wavelengths reflect off the mirror as shown in 403 of FIG. 4A . Note when located over the aperture, tilt in this axis alters the wavelength passing through the aperture. For the purposes of clarity, this axis will be hereafter referred to as the Spectral Selection Axis (SSA). Tilting of the grating about the orthogonal axis moves the spectrum orthogonal to its SSA, as shown in 404 of FIG. 4A . If there is no spatial reflectivity variation over the mirror in this orthogonal axis, to first order there will be no impact on the coupling of reflected light into the output collimator. However if there is spatial variation on that axis such that no portion of the beam falls on aperture 402 in FIG. 4A it is possible to use the mirror to position the spectrum on or off this aperture along this axis which will hereafter be referred to as the Spatial Positioning Axis (SPA). From a device function perspective the mirror in FIG. 4A has two different operation regions as shown in FIG. 4B . In region 405 the mirror does not split the beam, and all wavelengths for the device design are transmitted from the input to the express output, independent of the positioning of the SSA (within limits of the device Numerical Aperture). In Region 406 the device acts as a tunable filter because the beamsplitter redirects one portion of the spectrum, and the wavelength that is dropped is tunable through control of the tilt of the SSA. If region 406 were used exclusively, there would be a change in transmission “hit” on intermediate channels as the SSA was changed to drop the correct wavelength. However, the existence of region 405 and the ability to translate through that region without impacting transmission of other channels enables the feature of “hitless” tuning. This operation constitutes a Hitless Tunable Filter (HTF), the operation of which is shown in FIG. 4C . In this FIG, the grating is originally tilted such that the input spectrum is located to drop λ 1 as shown by beam projection onto the mirror surface noted 400 . Assuming a desire exists to tune the drop wavelength from λ 1 to λ n , then the grating would first be tilted on the SPA to position 410 , then tilted on the SSA to position 420 , and finally tilted back on the SPA to enable drop of λ n when the beam is positioned at 430 . The positioning of the SPA axis to operate the device in Region I during the tuning is the key to avoid interruption of the channel transmission of λ 2 through λ n−1 , thereby enabling the hitless operation. Note that the spectral properties of the beamsplitter 340 within region 406 are invariant with change in SPA along 404 . One means to leverage that variation is to create a variation in the beamsplitter properties along the slit (e.g. reflection angle, reflectivity, or absorption) such that the output coupled from region 402 varies with SPA, thereby providing a VOA to tune this output relative to the output coupled from the rest of the mirror.
The aforementioned devices are also extensible to multi-channel drop, including variable drop channel bandwidth. This is accomplished by having a beamsplitter for the drop bandwidth that varies spatially along the SPA axis. This could be continuously tunable if the beamsplitter width variation was continuous as shown in 501 of FIG. 5A , which would allow the drop bandwidth to be “tuned” by correctly positioning the tilt of the grating SPA axis to the position with the desired drop bandwidth. Tuning to wider filtering bandwidth is shown in the progression of the beam positioning from position 510 to 511 to 512 . The drop signal collection arrangement as shown in FIG. 3 is deficient as the drop bandwidth grows to multiple channels, because at the location of the drop collimator the different wavelengths are distributed spatially. Because the drop collimator coupling efficiency drops as the incident beam is offset from the optimum coupling, this effectively means the coupling efficiency will vary as a function of wavelength, yielding less ideal spectral filtering properties. Because this path is a drop port that a signal will only transit once, this spectral shaping does not have to be an ideal flat top, however this effect will cause unacceptable insertion loss and/or a rounded transmission spectrum when coupling many channels. One method to avoid this trade off is to reflect the drop signal back through the lens and grating system with a small mirror, 520 , that is tilted at a slight angle as shown in FIG. 5B , to enable the drop signal to couple into another collimator next to the input collimator. This approach spatially recombines the wavelength components reflected at an angle as shown in 523 into a single beam so they will couple to an output collimator with an insertion loss and spectral shape that is nominally independent of the bandwidth defined by the drop aperture. The independent, relative VOA capability described previously is one functionality necessarily lost when undertaking this double-pass approach because the beamsplitter variation along the SPA is used to change the bandwidth routed to a sperated output port, and therefore is not available to utilize as a VOA. Loss of this desirable feature may require that another degree of freedom be added to the drop device-coupling path such that optical power on that drop can be controlled. Possibilities include an independent degree of freedom to change the coupling of the drop collimator.
One potential drawback of the continuously variable beamsplitter geometry described above is that if the change in beamsplitter width is significant relative to the height of the beam on the mirror, this variation will degrade the filter function, changing the spectral transmission to make it less sharp than it would be with a constant width. Since tunable filter devices in general will require beams with cutting edge gratings, collimators and lenses to meet the stringent spectral filtering demands of DWDM applications, it is possible many applications will not be able to accept the filter degradation resulting from the continuous bandwidth tuning arrangement. However, an alternative approach could use step-wise beamsplitter transitions for the drop bandwidth as shown in 530 of FIG. 5C . Note that in FIGS. 5C-5F , the diagonal hatched mirror area is reflected in to the primary output port, and the square hatched area has a slight different reflection angle as shown in 5 B to couple to a different output collimator. This approach will not sacrifice the spectral filtering, but still can yield a number of regions that have significantly different bandwidths. Similar to the continuously tuned device, the bandwidth will be decided by which segment the SPA grating tilt positions the grating on, while the absolute wavelength registration has analog adjustment with the grating SSA tilt. Because these are independent control parameters, when new bandwidth is desired from the filters, the mirror adjustments can independently control how much bandwidth is added (within the constraints of the beamsplitter variation), and whether that bandwidth is added to shorter or longer wavelengths than the existing drop bandwidth (depending on the SSA grating position). It should be noted that when shifting spectral bandwidths in the stepwise beamsplitter shown in FIG. 5C the sharp change in the beamsplitter may disrupt neighboring channels during reconfiguration because it is not impossible to seamlessly change to a new bandwidth filter while maintaining the spectral alignment of one edge of the filter. To minimize this problem it may be desirable to smooth the transition of the stepwise beamsplitter as shown in FIG. 5D . This enables the filter bandwidth to change more slowly such that the center wavelength can be adjusted in tandem to effectively maintain the wavelength of one edge of the filter while shifting the wavelength of the other wavelength edge.
Unique demands for OADM applications place additional requirements that can impact the ideal beamsplitter geometries. For example, due to optical protection requirements in systems it may be desirable in OADM applications to have the transmission on the thru (express) path that becomes opaque when power is lost. If the beam-tilting arrangement relaxes to the center position when this happens, it would be desirable to have a beamsplitter as shown in FIG. 5E , where the central region 540 is completely etched away to remove all reflection when the tilt actuator is not powered. This region could alternately be tilted or covered with absorbing material to avoid coupling of light in that position to the through port. Note the beamsplitter in FIG. 5E also has two independent beamsplitter geometries 541 and 542 above and below central region 540 . This is useful because two independent modes of operation can exist for the same device. Thus the same device can have stepwise drop bandwidth of 541 if the mirror is tilted in one direction and continuously variable bandwidth of 542 if the device is tilted in the other direction. Both modes will have hitless capability if a beamsplitter-free mirror region exists to readjust the SSA as demonstrated in FIG. 4 .
Low PDL when transmitting through a beamsplitter is one additional constraint. PDL can be a problem when low cost metal mirrors (e.g. gold) are used as reflectors adjacent to a narrow slit. This causes a PDL problem because the polarization of light defines the plane of electric field oscillation, and the light experiences different absorption depending on whether the electric field is oriented parallel to the slit edge where it can oscillate conductive electrons in the metal coat, where as the orthogonal polarization cannot conduct electrons due to the lack of continuity of the metal in that direction. For this reason, it may be advantageous to dither the edge of any transition at the edge of the beamsplitter to impart a uniform effect on both polarizations (see FIG. 5F ).
The preceding arrangements are exemplary but not an exhaustive list of the functionalities that the present invention is capable of. For example it is foreseen that other mirror and beamsplitter arrangements can enable dropping bands of wavelengths in banded systems, and that the variable drop bandwidth slits in the SPA do not need to be contiguous bandwidth.
The arrangement shown in FIG. 3 is viewed as the preferred embodiment from a cost perspective, however there are a few reasons why this may not be optimum for the foreseeable future. For example, the most reliable, low cost 2 axis tilt mirror available today is an optical MEMS made with silicon processing, which is not optimized to be integrated with low PDL diffraction grating profiles desirable in this application. For this reason it may be desirable to separate the grating and tilt mirrors into separate elements as shown in FIG. 6 . This approach also requires more lenses and is necessarily less compact, however it can be readily fabricated with off the shelf components, and is likely cheaper and manufacturable in higher yields in the near term. The device operation is very similar to FIG. 3 , with the exception that a two-lens telescope ( 630 - 640 ) is placed between the tilt mirror ( 620 ) and the diffraction grating ( 650 ). The optical path starts with a collimated beam following the center line exiting the input collimator 601 and traversing prism 610 , which acts as an anamorphic beam expander to distort the circular beam that is output from the collimator into an elliptical beam that obtains higher resolution by illuminating more grating grooves. The beam then reflects off tilt mirror 620 into a telescope arrangement that effectively translates the tilt of the reflected beam off mirror to tilt of the incident beam onto the grating. When appropriately positioned with mirror 620 at the focus of mirror 630 and grating 650 at the focus of the lens 640 , the tilting beam will remain stationary at the same point on the diffraction grating, and furthermore the focal lengths of the two lenses in the telescope can be adjusted to match the full tilt range of the mirror to the desired tilt range of the incident beam on the grating. This minimizes the stability requirements on the tilt mirror, and enables optimization for different operation bandwidths (diffraction angle ranges) without changing the two most complex optical elements (grating and mirror). When tilted along the SPA of mirror 620 , the beam angle can be adjusted around the center line in the plane between the dashed lines. The diffraction grating is oriented with the grooves parallel to the plane of incidence from the telescope and would typically be positioned for nominal Littrow incidence angle. The diffracted beam is still collimated, but disperses laterally depending on wavelength (see dotted lines) before entering the lower portion of lens 640 . Because the diffraction grating is at the focal length of lens 640 it transforms the angular dispersion of the spectrum into a collimated, elliptical beam along the spectral dispersing axis (into the page). In the plane of the page, however, the beam is collimated coming into lens 640 and is focused on the mirror assembly 670 . All beam paths double pass the optional λ/4 waveplate whose axis is oriented to minimize polarision dependent loss of the device. Mirror assembly 620 acts as a beamsplitter for the incident elliptical beam, reflecting the beam reflected off surface 672 at the appropriate angle to coupling back through the device into thru collimator 602 . The portion of the beam incident on slit mirror 671 is reflected back through the device at a different angle aligned such that the beam couples into drop collimator 603 .
A further benefit of enabling the using the separate MEMs mirror enabled by the arrangement in FIG. 6 is that commercially available 2 axis tilt mirrors have embedded tilt position sensing mechanisms which can be readily used to accurately position the mirror for the correct wavelength and bandwidth drop in the absence of any input light. These sensors can also stabilize the mirror configuration to environmental changes and compensate for long term drift in the drive electronics.
OADM System Implementation
A compelling system architecture leveraging the functionality demonstrated from this device is shown in system 700 in FIG. 7 . This system uses the 3 port HTF 820 , 821 described above in the OADM configuration shown in FIG. 8A . The 820 HTF has the variable drop bandwidth capabilities at each node to seamlessly grow optical drop bandwidth at each node to meet unpredicted bandwidth demand while minimizing stranding bandwidth. This is accomplished by starting each of the 4 feeder nodes in this ring with 1 wavelength as shown in 720 , and appropriately spacing the initial wavelengths deplicted as solid, labeled lines among the dashed unused wavelength. As new wavelengths are needed, the HTF can add new drop channels on either the short or long wavelength side of its existing contiguous drop bandwidth. This decision can be made at provisioning time of the actual bandwidth demand as opposed to pre-planning. Because the decision regarding which wavelength to use is made later in time, the projection of where there will be spare capacity available should be more accurate. Furthermore, when deciding which new wavelength to provision—it is known the next contiguous short or long wavelength will be chosen, and it is known how many free wavelengths exist to share between the current node and the other node on the ring which shares that spare bandwidth. The wavelength on the side of the drop bandwidth with a higher ratio of supply (free wavelengths) to demand (any relative measure of the total demand at the two nodes for those wavelengths) should be used. Even when demands change with time, this approach tends to self-correct because if the supply/demand information is updated for each provisioning event, the wavelength allocation will shift to compensate for change in demand. The ability to incrementally add variable drop bandwidth is also amenable to adding channels with different data rates and different channel spacing to efficiently use the bandwidth for that data rate. While the wavelength selection procedure is described here as a manual process, it should be understood that this reasoning can be built into a wavelength assignment algorithm. Such algorthims are already used in modern WDM to optimize wavelength routing, and the procedure described above could be added to that algorithm to leverage readily available information to optimize the wavelength to use for a new demand. Note some of the relevant information to use in this algorithm are:
1. how many nodes are in the network 2. which nodes have similar contiguous bandwidth constraints 3. how many free wavelengths are available on the low and high side of the currently dropped bandwidth 4. how many wavelengths are already dropped at the node with the new wavelength request 5. and how many wavelengths are dropped at the two nodes which are neighbors in wavelength space
While this may seem to be an extensive list it is relatively straightforward to design such a simple algorithm that enables intelligent wavelength assignment, thereby minimizing wavelength stranding in the network.
It should be noted that this approach may not be 100% efficient and that some bandwidth can be stranded on the network. However, the ability to defer commitment regarding the wavelength allocation around a ring until provisioning time is very powerful to adjust to changing demands over time. This arrangement effectively enables the free channel bandwidth between any two nodes to be shared for upgrades rather than dedicated to a specific node. As shown in the exemplary wavelength assignments 721 , 722 and 723 in FIG. 7 , this enables bandwidth at a given node to be adjusted from a final drop bandwidth of 1 wavelength up to 19 wavelengths. This approach in general works better in rings with hub traffic and lower node counts, and it should be noted that if multiple wavelengths are dropped from the HTF those will need to be demultiplexed into individual wavelengths to route the signals to the appropriate transponder. Favorable OADM arrangements are shown in FIG. 8 , where the HTF 820 is used to drop wavelengths onto output 812 , while the express wavelengths which are not dropped continue to passive add coupling arrangement 831 before leaving the OADM on fiber 811 . FIG. 8B shows the demultiplexing of multiwavelength drop 812 where passive splitter 812 is used as an inexpensive means to create multiple drop ports will all wavelengths. The multiwavelength output from a splitter port can then be made single wavelength by subsequently adding an appropriate fixed or tunable filter ( 850 - 853 ). An alternate demultiplexing arrangement is shown in FIG. 8C , where multiwavelength drop port 812 can be coupled into skip-0 cyclical demux 860 . Cyclical demuxes are well known devices sold commercially as a colorless AWG by Neophotonics and ANDevices, or alternately sold as a PLC wavelength splitter by Hitachi Cable. An N port cyclical demux with the correct channel spacing is unique because a WDM input of any N contiguous wavelengths can always be demultiplexed into N individual output ports labeled 861 - 864 in FIG. 8C . This is significant in enabling a single code HTF based OADM that cost effectively demultiplexes a subset of the WDM channels. This works because the HTF in the present invention has a continuous drop bandwidth restriction, thus the cyclical demux is an elegant means to ensure single channel demultiplexing of any N channels in a single device.
It should also be understood that similar to the WSS, the HTF could be used as an adjustable transparent wavelength-dependent routing switch for WDM branching in mesh networks, and also for ring-interconnection or simple WDM cross connect applications. In all these applications the HTF does not bring the full flexibility of a WSS; however it will have a much lower cost which will potentially make it very valuable in applications where the more elegant WSS functionality does not add sufficient value to justify the cost.
The architecture leveraging the HTF as described in FIG. 7 is most advantageously deployed in networks with hub traffic patterns. This is because if one end of the service is always at the hub, that dramatically limits the number of different path combinations that must be supported by the optical layer. This architecture is most efficient when the total number of path combinations is limited such that the bandwidth shared between any two nodes represents a significant fraction of the total ring bandwidth. For mesh traffic patterns, there are significantly more possible path combinations that are needed, and the unpredictability of traffic demand becomes significantly more cumbersome. This is where the per-wavelength flexibility of the WSS enables the minimization of stranded bandwidth, thereby adding value to pay for the premium cost of the switch. However, even in mesh traffic rings, the HTF can bring a benefit for low traffic nodes. In this instance, the HTF would only drop 1 wavelength and would essentially function as an inexpensive WSS for that single drop. If the HTF costs ⅕ th of a WSS, then even if the devices are cascaded up to 3 or 4 drop ports the cost and insertion loss trade off would favor the HTF. This approach would require preplanning the number of HTF drops, however it will not require the additional drop path filtering necessary for the architecture in FIG. 7 . In this configuration the HTF could be deployed at smaller demand nodes in the same ring with WSS nodes, with automatic provisioning and drop wavelength selectivity that could provision line side bandwidth as discussed in US Appl. 20020145782.
While the aforementioned systems and subsystem arrangements are described within the context of WDM communication system applications, it should be understood by those skilled in the art that the capabilities to filter can detect different spectral components of light are applicable to a broad range of non-telecommunication applications. It is also recognized that the combination of a polarization-independent grating integrated onto a 2 axis tilt gimbal is a platform that can yield multiple other interesting devices as described below.
Multiple lower functionality tunable filter devices are possible, including a 3 port tunable filter that is not hitless because the availability of the Region I bypass area on the mirror is lacking. Alternately this or the hitless version might be deployed as an add filter or a wavelength blocker rather than a drop filter, where passive splitting or other components are used to access the signal in a broadcast and select architecture. This same approach can also be used to fabricate a 2-port tunable bandwidth selection filter that isolates a subset of the DWDM input channels that can be flexibly determined depending on the beamsplitter pattern on the mirror. All of these applications use only a subset of that demonstrated for the HTF, however because the spectral performance of this arrangement is superior to many of the devices available, and the cost and insertion loss are comparably low, this higher functionality device will likely be competitive in these applications as well.
Another application space of potential interest with the concepts of this invention is that of an Optical Channel Monitor (OCM). In this arrangement, the output collimator can be directed to (or replaced by) a single photodetector that is monitored as the grating or mirror tilt is used to sweep wavelengths across the detector. Continuous sweeping and refresh of the channel spectrum are available with arbitrary tilt control, and as desired more detailed measurements can be made on a single channel for troubleshooting, OSNR measurement or faster sampling for spectral changes in the system. A couple of unique OMON functionalities of this arrangement are the tilt degrees of freedom can be used to selectively couple input signal from any of multiple input collimators to the photo detector. This combination effectively integrates a switch with an OCM, enabling the OCM function (and cost) to be shared over multiple measurement points. A second unique feature of the tilt control is that it can be dithered to impart a specific amplitude modulation that in turn can reduce detection noise through frequency lock-in detection techniques.
One embodiment of the multiple input optical channel monitor is shown in FIG. 9 . FIG. 9 a displays the beam paths and the angular dispersion of wavelengths as they diffract off of the diffraction grating. Light from a first source enters the device through input collimator 900 . The input beam then diffracts off of a grating that is fabricated on a 2-axis analog tilt gimbal, 920 . The diffraction off this grating passes through a quarter waveplate, 930 , and is incident on a plane mirror, 940 . The axes of the waveplate are oriented to minimize the polarization dependent loss observed throughout the system. The beams diffracted off the grating consist of wavelengths diffracted at different angles. The wavelength corresponding to the beam perpendicular to the reflecting mirror 940 in the plane of dispersion will be reflected back toward the diffraction grating, with one component of its direction parallel to its incident path. The orthogonal component of the reflected beam direction, that component perpendicular to the plane of dispersion, is determined by the tilt angle of the grating, 920 , affecting that axis. The reflected beam makes a second pass through the quarter waveplate 930 and a second pass off the diffraction grating, which further disperses the light. The beam is then directed toward the detection collimator (element), 950 , where it is collected and detected. By rotating the grating about the axis parallel to the grating lines directs different wavelengths into the detection collimator. Rotating the grating in this manner through the range of motion of the grating allows the detection of the corresponding wavelengths and determination of the optical spectrum. Further, by rotating the grating about the axis which lies in the plane of the grating surface and is perpendicular to the grating lines, the spectral beams can be directed away from the detection collimator, 950 . This enables the configuration where no light enters the detection collimator. Such a state can be important for recalibration of dark current and other background drift with time and/or temperature. In this arrangement, there also exists a rotational position of the grating such that diffracted beams from a second source entering the device at the second input collimator, 910 , are be directed into the detection collimator, 950 . In a similar manner to that described above, the optical spectrum of the second source can be detected and determined. The beam propagation paths in the axis perpendicular to the plane of dispersion are shown in FIG. 9 b . For optimal detection of the two input sources, the input and detection collimators should be aligned such their virtual beams (beams that would be present if light were directed through all the fiber collimators) substantially intersect at the mirror, 940 . In this arrangement, there are two input ports and one detector port. It will be apparent to those skilled in the art that this invention is extensible to multiple input ports and multiple detectors elements.
As described previously, it may be desirable to separate the grating and tilt mirrors into separate elements. An embodiment of a multiple input port and multiple detector element optical spectral detection device employing separate grating and tilt mirror elements is shown in FIG. 10 . In this arrangement, light from a first source enters the device through input collimator 1001 of the fiber collimator array, 1000 . The fiber collimator array is constructed such that the virtual beams of each collimator in the array are substantially parallel. In this particular arrangement, the collimators are aligned in one dimension, though other arrangements could accommodate two dimensions. The axis along which the collimators are aligned, perpendicular to the beam propagation direction, will be call the port selection axis. The axis perpendicular to both the port selection axis and the beam propagation direction will be called the spectral selection axis. After the light enters the device through input collimator 1001 , it impinges on a cylindrical lens 1010 . As shown in FIG. 10 b , the cylindrical lens focuses light only in the port selection axis. The beam then is reflected off the analog tilt mirror 1020 , and directed to a lens system that comprises an aspherical lens 1030 followed by a cylindrical lens 1040 , with the cylindrical lens focusing light only in the spectral selection axis. After passing through the lenses, the beam diffracts of the diffraction grating 1050 , passes through a cylindrical lens 1060 and quarter waveplate 1070 before becoming incident onto mirro 1080 . The cylindrical lens 1060 focuses light only in the port selection axis. As evidenced by the FIG. 10 a and FIG. 10 b , tilting the analog tilt mirror 1020 along one axis enables light from any input collimator to be directed to any detection collimator and tilting the analog tilt mirror along the orthogonal axis enables the spectral components of those input sources to be detected and determined.
It is evident from the arrangement of FIG. 10 that the multiple input and multiple output spectral detection device can be employed to enable simultaneous sampling of multiple input sources using multiple detection elements. By configuring the geometry of the collimators in the collimator array 1000 with the appropriate symmetry, multiple input to output detector connections are made simultaneously. Typical applications requiring simultaneous sampling of multiple sources are those measuring a sample under test relative to a reference sample.
A further application that leverages the arrangement of FIG. 10 is to enable a device with significant enhanced spectral resolution. A doubling of the resolution of the device can be achieved by looping back one of the collection collimators into a second input collimator as displayed in FIG. 11 . In this configuration the input source will have diffracted off of the diffraction grating a total of 4 times. This can be extended further by adding additional collection ports, input ports and loopbacks.
For optical spectral detection applications, there may be advantages in some applications to employ a resonant scanning mirror rather than an analog tilt pointing mirror. The resonant scanning mirror is excited by an external driving force so as to oscillate the mirror continuously at its resonant frequency. There is a cost advantage of resonant scanning mirrors as they are used in high volume applications such as bar code scanners and laser printers. Additionally, such mirrors can have increased stability and immunity to mechanical disturbances because of their rotational inertia as they resonate.
More generally, the concepts of this invention are applicable to the field of optical spectroscopy. A typical optical spectroscopy application is to analyze the optical spectrum of an input signal over a targeted wavelength range. That is, the optical power as a function of wavelength is determined. The wavelengths ranges of interest can span the ultraviolet (UV), visible (VIS), near infrared (NIR), and infrared (IR) regions.
Yet another branch of extensions to this technology use a more complex 2 dimensional patterning of the entire reflection mirror in the HTF arrangement to obtain different functions. The first of these is an interleaver that alternately separates odd and even frequency channels from a common input. The mirror to achieve this would have a periodic beamsplitter pattern that alternately reflected a narrow range of wavelengths for each channel to what was described earlier as the output and drop ports (become even and odd ports in this application). Note that the active mirror is not necessarily required for this application if sufficient alignment accuracy and stability is possible. An advantage of this approach is that any pattern can be fabricated on that mirror, enabling an interleaver-like function, however with asymmetric odd/even channel spectra, aperiodic channel spacing, or any random arrangement of channels. Furthermore, if the mirror is present it could potentially be possible for hitless switching on the thru path between multiple of these possible functions. An example of this would be operating with a symmetric filter function until a high bandwidth channel is needed, at which point the device is tilted to a different tilt pattern that supports one or more higher bandwidth channels. A second pair of devices that utilizes a more complex spatially patterned mirror is a Dynamic Tilt Equalizer (DTE) or a Dynamic Gain Equalizer (DGE). This device is shown in FIG. 12 , which shows a spatial mirror profile that is highly reflective in the center, with reduced reflectivity on either side. This spatial variation of a very complex pattern can be obtained by local variation of a dielectric reflector, or by spatially patterning a mirror with spots of a broadband metal reflection coating that vary average reflectivity by controlling the fractional area coverage (by density or spot size). As shown in FIG. 12A , tilting the grating along the SSA from 1201 to 1202 enables one side of the spectrum or the other to be selectively attenuated as shown in graphs 1210 and 1211 . Thus the SSA tilt control becomes an adjustment for the spectrally dependent loss tilt, i.e. a DTE (SPA tilt could also be used with a more complex pattern). FIG. 12B shows how that concept can be extended to a more complex pattern that mimics the intrinsic gain shape change of an EDFA. In this configuration, the SPA tilt must be used for spectral adjustment because the spatial profile of the mirror is tied to specific wavelength features and SSA tilt would misalign that feature registration. It can be seen in this FIG. that moving the beam from 1201 to 1202 yields the desired wavelength-dependent loss spectrum to compensate an EDFA as shown in 1221 and 1222 . Although the mirror fixes the profile of this DGE, this will likely not be a problem for modern EDFAs which maintain minimal lot to lot variation of gain shape during manufacturing.
3 Port Hitless Tunable Filter Example:
Orient an array of 3 fiber pigtailed collimators in a linear manner, with a beam center to center spacing of 1 mm each having a Gaussian beam diameter of 500 μm. The center collimator of the three is the input collimator ( 601 ), the upper one the thru collimator ( 602 ), and the lower one the drop collimator ( 603 ). The beams should point in substantially the same direction, specifically the angular deviation between the propagation direction between the input beam and either the thru beam or the drop beam should be less than 0.5 mrad.
In front of the collimator array is positioned a beam expansion prism ( 610 ). The prism is coated with an anti-reflective coating to minimize loss (including polarization dependent loss) at the angle of incidence of incoming and outgoing light. The prism forms an angle between the 2 optical faces of 40 degrees and an index of 1.45 at a wavelength of 1550 nm. The input beam enters the prism at an angle of 73 degrees. It then exits near normal incidence with a horizontal beam expansion factor of approximately 2.6. This then yields a beam with approximately 1.3 mm beam diameter in the horizontal dimension and a 0.5 mm beam diameter in the vertical direction.
Following the propagation direction of light exiting the prism from the input collimator, the beam impinges upon a 2 axis tilt mirror ( 620 ) in close proximity to the prism. This mirror has an optically flat surface and can be actuated via electromagnetic coils to tilt up to 5.5 degrees in any of the 4 directions left, right, up or down. The surface of the mirror where the center of the beams hit is then located 1 focal length from an aspheric lens ( 630 ) optimized for transmission in the 1530 to 1565 nm range with a focal length of 8.2 mm. The clear aperture of this lens exceeds 6.5 mm diameter.
After the input beam propagates thru the lens ( 630 ), the light propagates in the same direction independent of the particular tilt angle of the mirror. The beam focuses to a waist at another focal length (8.2 mm) from the lens. A second lens ( 640 ) is then inserted in the optical path, one focal length from this minimum waist position. Then focal length of the lens ( 640 ) is 37 mm, giving a separation between the two lenses of 45.2 mm. The clear aperture of this second lens exceeds 12 mm. Note that if light were launched from the drop or thru collimators, these beams would cross at the same special location as the minimum waist position.
The input beam, upon exiting the second lens ( 640 ) becomes collimated once again, and hits a diffraction grating ( 650 ) one focal length later. This collimated beam now has Gaussian waist dimension approximately 4.5 times that of the beam exiting the prism, specifically 2.25 mm in the vertical direction and 5.85 mm in the horizontal direction. The beam center to center spacing between each port started as 1 mm but is now approximately 4.5 mm. These beams are still parallel. The grating ( 650 ) has 1100 lines per mm a clear aperture of 15 mm by 15 mm, and has been optimized to have high diffraction efficiency and low PDL around 1550 nm at the Littrow angle of 58.5 degrees. The grating lines are oriented vertically, with the grating tilted 58.5 degrees from the lens optical axis in the horizontal direction (for Littrow incidence) and 3 degrees downward in the vertical axis. Light scattering off the grating comes back toward the lens ( 640 ) at approximately the same angle in the horizontal direction but with some spectral deviation. Specifically, 1530 nm light comes off the grating at 56.1 degrees while 1565 nm light reflects at 59.7 degrees, measured with respect to the grating plane.
When the collimated input beam passes back thru the long focal length lens ( 640 ), it gets focused in both directions onto a reflecting mirror ( 670 ) positioned one focal length away from the lens. Before hitting the mirror, the light passes thru a ¼ wave plate ( 660 ) to rotate the polarization. The axis of the wave plate are oriented to minimize the polarization dependent loss observed throughout the system. In the vertical direction, the beam is focused to a diameter of 32 μm. In the horizontal direction, any given wavelength is focused to a beam diameter of 12 μm, but the center spot of a beam is shifted horizontally by 71 μm/nm. The mirror is tilted at approximately 7 degrees in the downward direction, and is aligned to the optical axis of the lens ( 640 ) in the horizontal direction. The mirror is located starting 3 mm below the line between the two lenses ( 630 & 640 ) and extends downward. The majority of the mirror ( 672 ) is highly reflective, but a small patterned slit is located in the horizontal center of the mirror, oriented in the vertical direction.
Located immediately behind (<0.5 mm) this slit is a second mirror ( 671 ) that is tilted upward in the vertical direction by approximately 7 degrees and is highly reflective. The slit starts at the upper edge of the mirror, with a width of 250 μm. This width extends downward for 150 μm. The slit then narrows to 224 μm and extends downward another 150 μm. The slit continues to narrow in steps to 112, 84, 56, and 28 μm respectively, each step having a height of 150 μm. After this the mirror is continuous with no slit.
Light from the input beam hitting the main mirror ( 672 ) is directed back thru the quarter wave plate, thru the long focal length lens ( 640 ), and onto the diffractive grating. This light is incident on the grating at the same angle that it left on the way to the retro-reflecting mirror (independent of wavelength), but is now offset by 4.5 mm in the vertical direction. Continuing back thru the two lenses, onto the tilt mirror and thru the prism, the light couples efficiently into the Thru collimator and fiber pigtail. With proper alignment (as outlined), the losses associated with this path are dominated by the diffraction efficiency of the grating and the small pass thru losses of each optical element. Input light that reflects off the secondary mirror ( 671 ) behind the slit also propagates back thru the optical system, but is offset by 4.5 mm in the opposite vertical direction when it hits the grating, thereby coupling into the Drop collimator and fiber pigtail.
The angular position of the tilt mirror determines both what wavelengths pass thru the slit and where the vertical spot is located on the retro-reflecting mirror. When no power is applied to the tilt mirror, the 1550 nm light is aligned vertically with the slit, and the beams are centered 75 μm above the retro-reflecting mirror. In this position, no substantial amount of light is coupled into the Thru or Drop collimators. As the mirror is tilted in the vertical direction, the light starts to move down and onto the retro-reflecting mirror. At first, a pass-band approximately 800 GHz wide is coupled into the Drop port while the remaining wavelengths are coupled into the Thru port. This has sufficient bandwidth and spectral roll-off for 16 channels spaced at 50 GHz. This pass-band is centered around 1550 nm. Increasing the vertical tilt of the mirror by approximately 0.5 degrees moves the beams to the narrower region of the slit, creating a 400 GHz pass-band. This continues as you continue to tilt the mirror in 0.5 degree increments, creating 200 GHz, 150 GHz, 100 GHz and 50 GHz pass-bands. In the case of the 50 GHz pass-band, the actual spectral characteristics are a 0.5 dB bandwidth of 39 GHz, a 3 dB bandwidth of 50 GHz, a 25 dB bandwidth of 82 GHz, and a 35 dB stop band of 16 GHz. These allow a single channel drop from a 50 GHz grid with appropriate pass-band and isolation. If the mirror is tilted even further, all wavelengths in the C band of 1530 to 1565 are coupled to the Thru port.
In this position, the horizontal tilt of the mirror can be changed, thereby changing the center wavelength to be coupled to the drop port. A Tilt of 5.4 degrees will center 1530 in the pass-band and a tilt of −5.4 degrees will center 1570 in the pass-band. Reducing the vertical tilt of the mirror now couples the chosen wavelength (e.g. 1530 nm) to the drop port. | An optical wavelength routing device utilizes a free space optical beam propagating therethrough is provided. The device includes at least one optical fiber input, at least one optical fiber output, an optical element having an actuator with at least one tilt axis and a diffraction element having a surface thereon. The device also includes an optical beam-splitting element having spatially varying optical properties. An optical beam transfer arrangement is positioned between the optical element and the diffraction element such that tilt actuation of the optical element elicits a proportional change in an angle of incidence of the optical beam onto the diffraction element, wherein the center of rotation for the angular change is the surface of the diffraction element. Optical routing between the fiber input and the fiber output can be configured by the positioning of the optical element. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a division of application Ser. No. 08/374,449 filed , filed Jan. 18, 1995, now U.S. Pat. No. 5,622,745, which is in turn a continuation of application Ser. No. 08/340,698 filed Nov. 16, 1994, abandoned.
FIELD OF THE INVENTION
The invention relates to methods for reducing particulates during manufacture of containers. More particularly, the invention relates to methods for reducing particulates during manufacture of metallic closure members for pharmaceutical containers.
BACKGROUND OF THE INVENTION
A pharmaceutical container typically includes an open-ended vial which is filled with a medicinal composition. The vial typically is sealed with a closure member in the shape of an open-ended cylindrical cup having a base and walls extending vertically therefrom, i.e., a shell cap. The shell cap aids in preventing contamination of the composition within the vial.
Manufacture of shell caps for use in pharmaceutical containers entails punching preforms from a sheet of lacquered metal such as aluminum, and subsequently shaping those preforms into shell caps. Often, the metal sheet is lacquered on only a single surface. During these punching and forming operations, the lacquer coating is broken whereby the resulting shell caps have bare metal surfaces and edges. These bare metal surfaces and edges of the shell caps generate metal particulates when the shell caps contact each other or other objects such as during transport of the caps. In addition, lacquer particles can be produced when the shell caps contact each other or other objects such as during transport of the caps.
Various processes for coating and protecting bare metal portions of containers have been proposed. For example, U.S. Pat. No. 4,451,506 shows coating the bare metal edges of a can blank with a polyamide adhesive tape. This method, however, cannot be employed practically if the metal is exposed to high temperatures as would be incurred during sterilization by autoclaving. Substituting plastic for metal also would not be acceptable since many plastics are not capable of dimensionally withstanding temperatures associated with autoclaving.
The presence of metal and lacquer particulate impurities is of special concern since the particulates can adhere to various portions of the shell cap. As a result, when the shell caps are washed prior to assembly to the vials, particulates on the shell caps can contaminate the pharmaceutical washing machines and thereby other components which might be washed in those machines. It also is important to prevent these particulate impurities from contaminating the medicinal compositions in the pharmaceutical container. A need therefore exists for minimizing the formation of particulates during the manufacture of pharmaceutical containers and closure members.
SUMMARY OF THE INVENTION
The invention provides a method for reducing the production of particulates during the manufacture of metallic components, especially manufacture of metallic components such as shell caps intended for use as pharmaceutical closures.
The method of the invention entails applying a solid polymeric coating to substantially all bare metal portions of metallic components to form coated components prior to permitting the coated components to contact each other or other objects. Desirably, the components are in the form of shell caps which are encapsulated by the solid polymeric coating.
The shell caps may be frangible or non-frangible. Frangible shell caps typically are provided with a solid polymer coating of about 6 microns to about 25 microns thick, especially about 13 microns thick. Coating materials useful with frangible shell caps include halogenated olefins, especially polytetrafluoroethylene. Non-frangible shell caps typically have a solid polymeric coating of about 25 microns to about 200 microns thick, desirably about 100 microns thick. Coating materials useful with non-frangible shell caps include polyesters, ethylene/acrylic acid ester copolymers, acrylic acid ester/acrylic acid copolymers, copolymers of vinyl esters, polycarbonates, polyureas, polyolefins, polypropylenes and polyurethanes. Both frangible and non-frangible shell caps can include an elastomeric liner such as rubber therein.
In another aspect, the invention provides a pharmaceutical container for storing medicinal compositions therein. The pharmaceutical container includes a vial for storing the medicinal compositions, and a shell cap for sealing the vial. The shell cap comprises a metallic substrate and a solid polymeric coating that substantially completely encapsulates the substrate. The shell cap can include an elastomeric liner therein. In yet another aspect of the invention, the pharmaceutical container can include an elastomeric stopper such as rubber over the opening to the interior of the vial. In each aspect, the shell cap may be frangible or non-frangible. A polymeric cover also can be provided over the shell cap.
The method of invention advantageously provides components such as shell caps which generate much less particulates when the shell caps contact each other or other objects during transport. The shell caps can be washed in pharmaceutical washers without fear of contaminating the washer and subsequent deposition of particulates on components which later may be washed in that washer.
Having briefly summarized the invention, the invention will now be described in detail by reference to the following specification, and non-limiting examples.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing summary, as well as the following detailed description of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings, like numerals are used to indicate like elements throughout.
FIG. 1 is an exploded view in cross section of a pharmaceutical container including a vial and a shell cap according to the invention;
FIG. 2 is an exploded view in cross section of a pharmaceutical container including a vial and a shell cap according to the invention wherein a rubber stopper is fitted into the vial; and
FIG. 3 is an assembly view in cross section of the pharmaceutical container shown in FIG. 2.
DETAILED DESCRIPTION OF THE INVENTION
Generally, the invention entails a method for reducing the production of particulates during manufacture of metallic components such as shell caps for pharmaceutical containers. In accordance with the invention, an abrasion resistant coating, especially a solid polymeric coating, is applied onto the bare metal surfaces and edges of components such as shell caps. Shell caps can be formed by punching a preform from a flat sheet of metal that may be lacquered on one or both sides. Non-frangible shell caps employ non-scored preforms whereas frangible shell caps employ scored or bridged preforms. The preforms can be punched from metals such as aluminum, aluminum alloys, stainless steel, copper and brass, preferably aluminum alloys. Desirably, the shell caps are formed by methods which enable the edges of the shell caps to have ripple free edges. Preferably, the shell caps are formed by the TruEdge® method of The West Company, Lionville, Pa. Lacquered shell caps formed by the TruEdge® method are available from The West Company, Lionville, Pa. under product codes 54202021, 54202054, 54130236 and 54130044.
The preforms, after forming into shell caps, are coated with a solid polymeric material to encapsulate the shell caps to eliminate exposed bare metal surfaces and edges. The thickness and composition of the applied polymeric material may vary depending on whether the shell caps are frangible or non-frangible. Typically, frangible shell caps have a thinner coating of polymeric material than non-frangible shell caps so that the frangible shell cap can fracture on score lines embedded therein. The force required to lift or fracture the shell cap along the score lines incorporated into the shell cap can vary by ±20% compared to lacquered metal shell caps. Frangible shell caps typically have a coating thickness of about 6-25 microns, preferably about 13 microns. The thickness of the polymer coating does not depend on the composition of the metal of the frangible shell caps. The total thickness of the coated frangible shell cap typically is about 200 microns.
The thickness of the solid polymeric coating applied to non-frangible shell caps is about 25-200 microns, preferably, about 100 microns. The total thickness of coated, non-frangible shell caps is about 250-560 microns, preferably about 400 microns.
Solid polymeric materials can be coated onto frangible and non-frangible shell caps by known methods such as vapor deposition, solution dipping, laser deposition, and fluidized bed. Preferably, the polymeric materials are applied to the shell caps in a fluidized bed wherein the shell caps are heated and then tumbled within a fluidized bed of the polymer powder to be coated and fused onto the shell caps. Use of fluidized beds to provide coated products is known in the art. See, for example, U.S. Pat. No. 4,000,338, the teachings of which are incorporated in their entirety by reference herein. Generally, the thickness of the polymer coating which can be applied to the shell caps in a fluidized bed is about 45 micron to about 450 micron. Specific conditions of temperature, exposure time, etc. to provide polymeric coatings on the shell caps by the fluidized bed readily can be determined by the art skilled.
The polymeric compositions which may be applied by a fluidized bed to shell caps may vary depending on the metal of the shell cap. For example, if the metal of the shell cap is heat sensitive, higher modulus polymeric material may be applied to the shell cap so that the modulus of the coated shell cap is in a desired range. The polymeric compositions applied to the frangible and non-frangible shell caps are resistant to abrasion to avoid generating polymeric impurities as well as to avoid exposing the metallic surfaces and edges of the shell caps. Abrasion resistance of the polymer coating can be determined by treating "pharmaceutically washed" shell caps in a centrifugal feed bowl operating at 100-150 rpm for 30 minutes and measuring the amount of polymer and metal particulates produced.
Various polymers may be coated onto non-frangible shell caps. Useful polymers include but are not limited to polyesters such as polyethylene adipate, polyethylene sebacate, polyethylene terephthalate, poly tetra methylene isophthalates; ethylene/acrylic acid ester copolymers, acrylic acid ester/acrylic acid copolymers, ethylene/acrylic acid copolymers, styrene/methacrylic acid esters/acrylic acid copolymers, and the like; copolymers of vinyl esters such as saponified ethylene/vinyl acetate copolymers, ethylene/vinyl propionate copolymers, ethylene/vinyl acetate copolymers, acrylic acid ester/vinyl acetate copolymers and vinyl chloride/vinyl acetate copolymers; ionomers such as Surylns® produced by E.I. DuPont de Nemours & Company; copolymers of maleic anhydride with vinyl monomers, and maleic anhydride modified polyolefins such as maleic anhydride/styrene copolymers; polycarbonates such as poly-p-xylene glycol biscarbonate; polyureas such as polyhexamethylene urea; halogenated polymers such as polytetrafluoroethylene; polyurethanes, polyolefins, polypropylenes and terpolymers such as ethylene-propylene-dienes. Preferably, amide type resins such as Nylon 6, Nylon 66, Nylon 11 and Nylon 12 are coated onto the non-frangible shell cap.
A variety of polymeric compositions also can be applied to frangible shell caps. Useful polymers include but are not limited to halogenated olefins such as polytetrafluoroethylenes, preferably Teflon®, and Vidax® available from E.I. DuPont DeNemours & Company.
In a further aspect of the invention, a pharmaceutical container that incorporates the coated shell cap of the invention is provided. In this aspect, the shell cap optionally can be fitted with an elastomeric liner prior to assembly to the vial component of the pharmaceutical container. As shown in FIG. 1, a pharmaceutical container 10 is provided. Pharmaceutical container 10 includes vial 5 and shell cap 12. Optional liner 15 is fitted to the inner surface of shell cap 12 having polymeric coating 25 thereon. Shell cap 12 includes metal substrate 1 and polymeric coating 25 thereon to encapsulate substrate 1, including the surfaces and edge portions of substrate 1. When shell cap 12 is fitted to vial 5, liner 15 engages edge 7 of vial 5 to provide an additional seal to protect the contents within vial 5. Liner 15 may be any polymer having elastic properties suitable for use as a sealing material. Materials useful as liner 15 include but are not limited to elastomers such as butyl rubbers, silicone rubber, and chloro-butyl rubbers. These elastomers may be blended with additives such as oxidation inhibitors, heat stabilizers, fillers or colorants. These additives are known in the art.
In a further embodiment of the invention as shown in FIG. 2 and FIG. 3, elastomeric stopper 17 is inserted into opening 8 in neck portion 9 of vial 5 prior to sealing of vial 5 with shell cap 12. Stopper 17 may be produced from elastomeric materials such as butyl rubbers, silicone rubber, and chloro-butyl rubbers. In each embodiment as shown in FIGS. 1-3, shell cap 12 can be joined to vial 5 by crimping. Polymeric coating 25 provided on shell cap 12 has sufficient thickness and strength to withstand the crimping operation without generating particulates.
In each embodiment of pharmaceutical container 10 as shown in FIGS. 1-3, cover 20 optionally can be provided over shell cap 12. Cover 20 may be formed of polymeric material and can be readily removed from shell cap 12. Cover 20 on shell cap 12, when shell cap 20 is sealed to vial 5, usefully indicates attempts at tampering with pharmaceutical container 10. Cover 20 also provides a useful dust cover for container 10.
The coated shell caps of the invention have been found to generate about one-tenth the amount of particulates produced by conventional lacquered shell caps when those shell caps contact each other or other objects during transport. The amount of particulate can be determined by depositing the shell caps into a 500 ml polypropylene container with a screw cap that is filled with about 100 ml of filtered, deionized water. The number of shell caps added to the container depends on the size of the shell cap. If the shell cap is less than about 13 mm, 25 shell caps are added. If the shell cap is larger than about 20 mm, 15 shell caps are added. The container is shaken in an orbital shaker for 30 minutes at 30 rpm. The water in the container is filtered through 0.45 micron filter paper. The number of particles measuring more than 25 microns on the filter paper are counted visually under a microscope. The number of particles per shell cap equals the number of particles divided by the number of shell caps.
It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims. | A method is provided for reducing particle formation during manufacture of shell caps for containers such as pharmaceutical containers. The method entails providing a solid polymeric coating on substantially all surfaces of the shell caps to form coated shell caps before permitting the coated shell caps to contact each other or other objects. A pharmaceutical container which employs the shell caps also is provided. The container comprises a vial for storing medicinal compositions therein and a shell cap for sealing the vial. The shell cap includes a hollow metallic preform and a solid polymeric coating which substantially completely encapsulates the preform. | 2 |
FIELD OF THE INVENTION
[0001] The invention is directed to polarizing glasses and a method for making such glasses. In particular, the invention is directed to a silver-containing glass composition and a noble metal from the group consisting of platinum, palladium, osmium, iridium, rhodium and ruthenium, and a method for making the polarizing glass that does not require a reducing atmosphere step.
BACKGROUND OF THE INVENTION
[0002] A polarizing effect can be generated in glasses containing silver, copper or copper-cadmium crystals. These crystals can be precipitated in a boroaluminosilicate glasses having compositions containing suitable amounts of an indicated metal and a halogen other than fluorine.
[0003] The polarizing effect is generated in these crystal-containing glasses by stretching the glass and then exposing its surface to a reducing atmosphere, typically a hydrogen containing atmosphere. The glass is placed under stress at a temperature above the glass annealing temperature. This elongates the glass, and thereby elongates and orients the crystals. The shear stress that acts on the particles is proportional to the viscosity of the glass and the draw speed during elongation. The restoring force that opposes the deformation by the shear force is inversely proportional to the particle radius. Hence, the optimum conditions for producing a desired degree of particle elongation and a resulting polarizing effect at a given wavelength involves a complex balance of a number of properties of the glass and the redrawing process. Once the glass has been elongated, the elongated glass article is then exposed to a reducing atmosphere at a temperature above 120° C., but not over 25° C. above the glass annealing point. This develops a surface layer in which at least a portion of metal halide crystals present in the glass are reduced to elemental silver or copper.
[0004] The use of silver halide as a polarizer material capitalizes on two properties of the silver halide that are (1) the liquid particle is very deformable, and (2) it is easier to make larger and controlled particles sizes. The disadvantages of using silver halide are (1) that one cannot make polarizers that operate at wavelengths shorter than red (approximately 650 nm) because of the refractive index of the silver halide and (2) that the process required a hydrogen reduction step. It is possible to stretch silver particles in glass as described in by E. H. Land in U.S. Pat. No. 2,319,816 and later by S. D. Stookey and R. J. Araujo in Applied Optics , Vol. 7, No. 5 (1968), pages 777-779. However, the problems encountered are the control of particle size and distribution, especially for visible polarizer application where the aspect ratio of the particle is smalls, typically 1.5-2 to 1.
[0005] The production of polarizing glass, as is described in the patent references provided below, broadly involves the following four steps:
1. Melting a glass batch containing a source of silver, copper or copper-cadmium and a halogen other than fluorine, and forming a body from a melt; 2. Heat treating the glass body at a temperature above the glass strain point to generate halide crystals having a size in the range of 500-2000 Angstroms (Å); 3. Stressing the crystal-containing glass body at a temperature above the glass annealing point to elongate the body and thereby elongate and orient the crystals; and 4. Exposing the elongated body to a reducing atmosphere at a temperature above 250° C. to develop a reduced surface layer on the body that contains metal particles with an aspect ration of at least 2:1.
[0010] Glass polarizers, the material compositions and the methods for making the glasses and articles made from the glasses have been described in numerous United States patents. Products and compositions are described in U.S. Pat. Nos. 6,563,639, 6,466,297, 6,775,062, 5,729,381, 5,627,114, 5,625,427, 5,517,356, 5,430,573, 4,125,404 and 2,319,816, and in U.S. Patent Application Publication No. 2005/0128588. Methods for making polarizing glass compositions and or compositions containing silver, and/or articles made from polarizing or silver-containing glasses have been described in U.S. Pat. Nos. 6,536,236, 6,298,691, 4,479,819, 4,304,584, 4,282,022, 4,125.405, 4,188,214, 4,057,408, 4,017,316, and 3,653,863. Glass articles that are polarizing at infrared wavelengths have been described in U.S. Pat. Nos. 5,430,573, 5,332,819, 5,300,465, 5,281,562, 5,275,979, 5,045,509, 4,792,535, and 4,479,819; and in non-U.S. patents or patent application publications JP 5-208844 and EP 0 719 741. The Japanese patent publication describes a copper-based polarizing glass instead of a silver-based polarizing glass.
[0011] While there have been considerable efforts in the art to improve polarizing glasses and the methods used to make them, there is still considerable need for further improvement. In particular, it would be advantageous to have a glass and a method for making the glass that does not require the use of a reducing atmosphere step. While it possible to stretch silver (Ag) particles, there are very considerable problems with regard to controlling particle size and distribution. These difficulties are particularly pronounced regarding visible light polarizers where the aspect ratio is small, typically 1.5-2 to 1. Accordingly, it is the object of the present invention to provide a polarizing glass composition that does not require a reducing atmosphere step and a method for making such glass. In particular, it is an object of the present invention to provide a polarizing glass composition utilizing silver and an additional selected noble metal, wherein the additional noble metal is used to nucleate atomic silver to silver metal particles without the use of a reducing atmosphere step, and a method for making such glass.
SUMMARY OF THE INVENTION
[0012] The present invention is directed to a silver-containing polarizing boroaluminosilicate glass composition that has been doped with an additional noble metal selected from the group consisting of platinum (Pt), palladium (Pd), gold (Au), iridium (Ir), rhodium (Rh) and ruthenium (Ru), wherein the additional noble metal is used to nucleate atomic silver to form silver particles.
[0013] The invention is further directed to a silver-containing boroaluminosilicate polarizing glass composition that has been doped with platinum to thereby nucleate silver ions to form silver metal particles without requiring the use of a reducing atmosphere step or other reductants known in the art such as antimony, starch, sugar or cerium.
[0014] The invention is additionally directed to a method for making a silver-containing polarizing boroaluminosilicate glass composition containing silver and an additional selected noble metal, preferably platinum, to nucleate atomic silver to form silver particles without the use of a reducing atmosphere step.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 illustrates the polarized transmittance spectrum of two redrawn Pt-doped glass compositions having a heat treatment at temperatures of 600 and 650° C., respectively, prior to drawing.
[0016] FIG. 2 illustrates transmittance in the null (“N”) and through (“T”) for the two glasses of FIG. 1 .
[0017] FIG. 3 illustrates visible light polarizer bars that have been drawn, with a finished bar on the right and an as-poured bar on the left.
[0018] FIG. 4 illustrates a glass bar after drawing on right, drawn glass ribbon in the middle and a root or gob of glass from start-up.
[0019] FIG. 5 illustrates a furnace, load cell and glass bar suspended in the furnace.
[0020] FIG. 6 illustrates an alternative furnace, load cell, downfeed and glass bar suspended in the furnace.
[0021] FIG. 7 illustrates the pulling device (tractor) system of the alternative furnace as used in attenuating the glass down during the draw.
[0022] FIG. 8 illustrates a ribbon of glass exiting the alternative furnace and being drawn down.
[0023] FIG. 9 illustrates a comparison of polarized transmittance of redrawn ribbon from the two different drawing systems.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The term “noble metal”, as used herein with the regard to the metal dopant added to the silver containing glass, refers to the one or more metals selected from the group consisting of platinum (Pt), palladium (Pd), gold (Au), iridium (Ir), rhodium (Rh), osmium (Os) and ruthenium (Ru). The term “noble metal” as used herein also excludes the silver contained in the glass compositions of the invention.
[0025] The method of making a polarizing article by redrawing at high stress a glass containing a silver halide (“Ag X” where X is a halogen) phase is well documented. For example, see U.S. Pat. Nos. 6,536,236, 6,298,691 and 4,304,584, and other method patents cited herein. The utility of this process, invented by Corning Incorporated, was in the recognition that it was easier to elongate the silver halide particle at the size distribution that was formed in photochromic glass than it was to elongate a silver particle in an arbitrary glass. Once the Ag halide particle was elongated, it was then reduced in a hydrogen-containing atmosphere to form the required elongated metallic silver particle. Although the direct elongation of a metallic silver particle is possible, the elongation requires a much higher stress. However, this fact does not preclude the situation where, if one finds a glass composition and a process where large silver crystals can be controllably formed, that one would not be able to reduce the stress required to provide reasonable elongation of metallic silver particles. One advantage of the direct metallic silver particle elongation process is that in the resulting product the material surrounding the silver has a lower refractive index relative to the bulk glass. This keeps the surface plasmon resonance at a shorter wavelength, which is important for making polarizers that operate in the visible portion of the spectrum.
[0026] The glass composition of the invention that has the property of controllable large silver particles is derived from the compositions used for gradient index lenses (see U.S. Pat. No. 6,893,991 B2). In gradient index lens glass compositions the glass contains a high concentration of a polarizable ion, for example, Ag + or Cu 2+ , and the ion can be readily ion-exchanged. In the present invention it was important to have a glass composition retain some silver as atomic silver until it can be nucleated to metallic silver is conducted as described herein.
[0027] The base glass composition according to the invention contains the following range of materials in weight percent [wt. %].
TABLE 1 SiO 2 20-60 Al 2 O 3 5-20 B 2 O 3 10-25 Ag 15-40
[0028] In making the base glass composition the Si, Al and B materials can be added as oxides and Ag is added as the nitrate or as a mixture of silver nitrate and silver peroxide. Additionally, at least one noble metal salt or salt solution is added to the base glass composition and the resulting composition is mixed. The noble metal, or mixture of noble metals if more than one is used, is selected from the group consisting of platinum, palladium, gold, osmium, iridium and ruthenium salts, The noble metal, or mixture of noble metals, is present in an amount in the range of 0.0025 wt. % to 0.5 wt. % (measured as total zero-valent noble metal), preferably in an amount in the range of 0.01 to 0.3 wt. %, and it can be added as a halide, nitrate, or complex such as an acetylacetonate, oxalate or crown ether or other complex known in the art, or as a solution of any of the foregoing. In a preferred embodiment the base glass composition according to the invention is approximately (in weight percent ±2 wt. %):
TABLE 2 SiO 2 34 Al 2 O 3 17 B 2 O 3 14 Ag 35
and the noble metal is Pt in amount in the range of 0.0025 wt. % to 0.5 wt. % (measured as total zero-valent noble metal), preferably in an amount in the range of 0.01 to 0.3 wt. %, and most preferably in an amount in the range of 0.02 wt. % to 0.2 wt. %
[0029] When the base glass composition alone is melted in a quartz crucible at approximately 1350° C. for approximately 16 hours, a clear, slightly yellow glass is produced. The slightly yellow color of the glass is indicates that substantially all of the silver is dissolved in the glass composition as the silver +1 ion. The glass also fluoresces under ultraviolet light indicating that al least some of the silver is present at atomic silver. Upon adding only a slight amount of a noble metal, for example, platinum, to the base glass composition the slightly yellow color of the glass turns to a deep red-brown color that is indicative of the presence of large colloidal silver particles. Small silver particles produce a yellow color whereas the large particles produce a light scattering effect in addition to the absorption. This is the appearance of a Pt-doped glass; that is the color is deeper and darker due to the light scattering effect. The level of Pt, or other noble metal(s), needed to induce this change is in the range of 0.0025 to 0.5 wt. %. Once the nucleation or formation of metallic silver has been carried out, one can further increase the density of the color (that is, the amount of precipitated colloidal silver particles) by heating the glass to a temperature in the range of 500-800° C., preferably to a temperature in the range of 600-750° C. for a time in the range of 2 to 6 hours at temperature. This ability for further effect precipitation gives one additional control over the amount of silver that is present as metallic silver crystals in the glass. In addition, a further heat treatment at a temperature in the range of 500-800° C. for a time in the range of 0.5 to 6 hours enables one to grow larger silver crystals.
[0030] Once the nucleation/precipitation has been completed, the glass is than shaped prior to drawing, for example, by molding or by cutting a glass boule into a desired shape, and Blanchard ground into bars, for example bars that are 10 to 40 inches long, 3-4 inches wide by approximately 0.25 to 0.6 inch thick. To allow higher draw forces on the glass, an etching process, or a thermal treatment, or both, is used to remove or heal surface and subsurface defects that are introduced during the grinding process. When a glass surface is mechanically removed (for example by grinding), many surface and/or subsurface fractures or flaws can either result or become exposed. Under an applied stress these fractures or flaws can propagate into the glass body causing the glass to fracture. By chemically etching and/or thermally treating the glass surface the flaws are healed by rounding out the fracture (flaw) surface, or by closing it using a thermal treatment. Thermal treatments are generally carried out at a temperature near (within 25-50° C.) the softening point of the glass composition. As an example of etching, prior to drawing the glass, the glass bar is immersed in a dilute hydrofluoric acid solution for a period of time sufficient to remove a portion of the surface to remove contamination and flaws. If deemed necessary, visual inspection, with or without the use of magnification, can be used to determine when the process is completed. The glass bars are then drawn under conditions where the draw temperature allows a glass viscosity greater than 10 6 poise and a pulling velocity that is sufficient to apply a force greater than 3500 psi (>3500 psi) to elongate the silver particles.
[0031] FIG. 1 illustrates the polarized transmittance spectrum (uncorrected for reflectance) of a redrawn Pt-doped glass having the composition given in Table 2. It was determined that at pulling velocities less than 3500 psi (<3000 psi) the elongated silver particle aspect ratio is small and therefore the null direction transmission increases at lower wavelengths. For a polarizing glass operating at lower wavelengths, for example, in the visible range, this increase in null direction transmission is undesirable. When the applied force to stretch the silver, which force is controlled by the viscosity of the glass and velocity of the draw speed, is greater than 3500 psi, a glass material with an acceptable polarizing behavior in the visible range was obtained. Further, it is preferable to apply to the drawn glass as great a force as the mechanical strength of the glass and the equipment will permit in order to achieve the desired elongation of the silver particles. The unpolished glass sample illustrated in FIG. 1 had a transmission is 60% in the pass or through direction (that is, light passing through the glass in the direction perpendicular to the direction of elongation) and essentially 0% transmission in the null or stop direction (that is, no light passing through the glass in the direction parallel to the direction of elongation).
[0032] FIG. 2 illustrates on a single graph the polarized transmittance spectrum (uncorrected for reflectance) in the range of 400-800 nm (visible range) of two samples of a drawn Pt-doped glass having the composition given in Table 2. Sample A (illustrated by the solid line, and which is the same as the sample as illustrated in FIG. 1 ), was given a pre-draw heat treatment at 650° C. and Sample B (illustrated by the dashed line) was given a per-draw heat treatment at 600° C. For each sample light transmission in the direction perpendicular (through or pass direction) and parallel (null or stop direction) to the direction of elongation of the silver particles it shown by the capital letters “T” and “N”, respectively.
[0033] FIG. 2 illustrates that one can selectively determine the wavelength or wavelength range in which light will be polarized when a silver-containing glass is doped with a noble metal, heat treated and drawn in accordance with the invention to thereby elongate the silver particles therein. For Sample A, the glass composition was heat treated at 650° C. prior to drawing. As one can see from the graph, transmittance in the null direction (N) direction is essentially zero in the range of approximately 475-550 nm. Sample B, which is the same glass composition as Sample A, was heat treated at 600° C. prior to drawing. For this sample the transmittance in the null direction is below 10 in the approximate range of 425-480 nm. For both glass sample transmittance in the through (“T”) direction are similar through the range measured. This comparison illustrates the aspect of the invention which is that by use of a noble metal in a silver containing glass, one can tailor the null range of the glass by appropriate heat treatment prior to drawing the glass. As a result, one is able to form a glass that selectively polarized a selected wavelength range. As shown in FIG. 2 , by controlling the heat treatment one can determine the performance of a glass at a given wavelength by regulating the silver particle size. In FIG. 2 , the further the null peaks are shifted to the right. The shift of the null peak represents better elongation of the particles or greater aspect ratio, and based on the assumption that larger particles are easier to elongate, it is concluded that the particles in the glass are larger. Thus, the curves also show that when a glass is heat treated at lower temperatures we have smaller particles that are more difficult to elongate during draw.
[0034] A further advantage of the glass according to the invention that when stretched it has both good transmission and contrast values at 535 nm (green polarizer application). Moreover, these values are attained without the need for hydrogen or other reducing atmosphere treatment. The Pt-doped glass according to the invention represents a totally new glass composition for polarizer applications.
[0035] The process according to the invention was developed to allow a high through put of different glass compositions in order to investigate their potential for polarization applications using a redraw technique. The AMPL (for Corning's Advanced Material Processing Laboratory) draw tower (purchased from Heathway Ltd, now Herbert Arnold GmbH & Co. KG, Weilburg, Germany) as shown in FIG. 5 is comprised of a downfeed system, furnace 40 and pulling tractors (not illustrated) that were used to stretch-down glass bars under high tension. Various glass compositions were melted in a crucible then poured into a bar form using a mold. The bars were then either machined finished or used as-poured in the drawing process (see FIGS. 2 and 3 , described below). For the testing described herein, the bars 30 are approximately 2 inches wide by 10 to 40 inches long, and were of varying thicknesses ranging from 0.25 to 0.60 inches. Holes were drilled on each end of the bars (see FIG. 3 illustrating one end of a bar); one hole being used to hang the bar from a metal cylinder 22 on the downfeed system and the other hole was used to grasp the bar to start the drawing process. A load cell 20 was attached to a metal cylinder 22 that was held in the place in the downfeed chuck 24 and the other end of the load cell supported the glass bar. The furnace 40 was a graphite resistance furnace that can span a wide temperature range. The furnace was controlled using a pyrometer and programmable controller. The glass bar was suspended in the furnace by a wire 26 connected to the metal cylinder 22 plus load cell 20 as shown in FIG. 5 .
[0036] After placing the bar in the furnace, the furnace temperature was raised to a temperature at which the glass was soft enough to enable pull-down. For the platinum-doped glass of the invention a temperature of 725° C. was used for drawing the glass. Once the glass was initially pulled down, the downfeed which lowers the glass bar into the furnace at a controlled rate was started. The feed rate of lowering the glass down was set at 13 mm/min. The tractor unit is comprised of two motor driven belts (located below the furnace) opposing each other and rotating in opposite directions so that the motion through the belts is downward. The distance between the belts can be set so that the glass being drawn through can be grasped by the belts and does not slip in the belts.
[0037] FIG. 3 illustrates visible polarizer bars that have been drawn as described above. The bar on the left, colored a light yellow, is a bar as-poured that was drawn without the addition of a noble metal and the bar at the right, dark reddish-brown, is a finished bar containing noble metal and drawn as described herein. FIG. 4 illustrates a glass bar on the right, a drawn glass ribbon in the middle, and a root or gob of glass on the bottom of the bar from start-up. When the bottom portion of the glass bar is drawn down it is a large gob (root) and has to be hand drawn down through the tractor unit, which is approximately two feet below the furnace bottom. Once the root of glass is passed through the tractor belts the smaller ribbon of glass is placed in between the belts and the belts closed so that they are pulling the glass (see FIG. 5 ). The tractor belt speed is then set to a rate that is pulling the glass ribbon down to a specific size. For the platinum doped glass of the invention, a tractor speed of 2.04 m/minute was used. The ribbon can vary in size until all the draw parameters stabilize. In the example shown in FIG. 4 the final size of the ribbon was approximately 3.5 mm (0.138 in.) by 0.50 mm (0.02 in.).
[0038] The purpose of the draw is to induce a tensional force to stretch the polarizing component in the glass, which is usually accomplished at high tensions. The load cell records the force being applied on the glass bar as it is being pulled down by the tractor belts. The load being applied on the glass can be adjusted by changing temperature, downfeed rate or tractor speed. Typically, at the start of the draw the load is small and incremental adjustments, typically by changing temperature, are made to increase the tension on the glass. Sometimes several adjustments are required before a high enough tension is present on the glass. If the load is too great, the ribbon of glass will break and the start up process has to be repeated. Once a high load is achieved, the glass ribbon is marked, the draw parameter(s) recorded, and the ribbon saved. The ribbon geometry is also recorded in order to calculate the force per area applied on that particular piece of glass.
[0039] A second draw apparatus (the PRC draw apparatus) was used for further development of the silver based polarizing glass which had been used on Polarcor™ development. This draw consists of a seven zone rectangular furnace 50 , a downfeed system 52 , load cell 54 (see FIG. 6 ) and a tractor pulling unit 56 (see FIG. 7 ). FIGS. 6 and 7 illustrate the PRC draw system which is similar to the AMPL system with regard to processing, except that the furnace and tractor are not incorporated on a tower structure. The other major difference between the two draw systems is the seven zone furnace on the PRC system. This allows tighter control of the temperatures and the ability to adjust different zones to provide the thermal profile best for drawing.
[0040] The two benefits the PRC draw is the ability to draw larger (wider) bars resulting in wider ribbon and the tractor unit allows greater pulling stresses to be applied to the glass. FIG. 8 shows a picture of the ribbon exiting out of the furnace above the pulling tractor unit. The tractor incorporates wider and longer belts to provide more surface area in contact with the ribbon which eliminates slippage in the tractor.
[0041] The procedure for drawing the glass on the PRC draw is the same as described above with the AMPL draw. The draw parameters for the PRC system that resulted in good polarizing ribbon were in the range of 6 to 8 inch/min. draw speed and a temperature between 620° C. to 650° C. The resulting ribbon geometry is on the order of 15 to 20 mm wide and 0.8 to 1.3 mm thick. Samples were collected during the draw along with the load and draw parameters and then analyzed in a spectrophotometer.
[0042] Results from the PRC draw are shown in FIG. 9 compared to a result from the AMPL draw. It is seen that the Null curve is broader and has a steeper slope at longer wavelengths. This correlates to the PRC draw system ability to apply higher stress and elongating the silver particles to greater extent. This result provides a wider polarization wavelength window and a greater contrast ratio.
[0043] While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims. | The invention is directed to a silver-containing polarizing boroaluminosilicate glass composition that has been doped with a noble metal selected from the group consisting of Pt, Pd, Os, Ir, Rh and Ru, including mixtures thereof,to nucleate and precipitate silver ions to silver metal without the need for a reducing atmosphere step. The invention is further directed to a method for making the glass composition of the invention. Using the composition and method of the invention, one can prepare a glass having a selected null transmission range. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefits of European application No. 07017913.0 filed Sep. 12, 2007 and is incorporated by reference herein in its entirety.
FIELD OF INVENTION
The present invention relates to a device for deflection and/or strain measurement in elongated wind turbine elements like, for example, wind turbine rotor blades and wind turbine towers. The inventive deflection and/or measurement may be used for feedback to a cyclic pitch controller.
BACKGROUND OF THE INVENTION
In many aspects elongated members of wind turbines are exposed to stress that causes strain. For example, the tower of a wind turbine as well as the wind turbine rotor blades may be exposed by strong wind which causes a strain on the tower and the rotor blades. The load on the rotor blades and/or the tower may be reduced by a variation of the blade's pitch. This can be realised by individual pitch controllers in general or by a cyclic pitch controller.
An effective pitch control, for example for reducing the loads acting on the rotor, needs information about the load acting on the blade root which can be extracted from a determination of the rotor blade deflection. Optical fibres in the blades are typical sensors for a reliable and long term measurement of the rotor loads. Such systems are rather expensive.
In U.S. Pat. No. 7,059,822 B2 a method for determining a rotor blade deflection is disclosed wherein a rotor blade is coupled with a hub. The rotor blade includes a beam with a first end coupled to a baffle inside the rotor blade, while the second end of the beam is located adjacent to the hub and is used for measuring the deflection of the beam by means of at least one sensor located in the hub. The beam is located near the centreline of the rotor blade. The determination of the deflection of the blade is based on the movement of the beam which correlates with the blade deflection.
In WO 03/029750 A1 a sensor construction for measuring the bending of a construction element is disclosed. It comprises a rod element positioned offset relative to the deformation neutral line/surface for the bending to be measured. A first end of said rod element is firmly connected to the construction element and a second end of said rod element is connected to the construction element. The second end connection provides a movability in the axial direction of the rod element. The measurement is performed by measuring the position of the second end of the rod element relative to the construction element.
In US 2006/0000269 A1 a method for determining rotor blade deflection is described, wherein a rotor blade is coupled to a hub. A first end of the a beam is coupled to the rotor blade. A second end of the beam is positioned adjacent the hub. The deflection of the beam is measured by use of at least one sensor. The deflection of the blade is determined based on the deflection of the beam.
In US 2006/0201257 A1 a gas turbine blade fatigue life evaluating method for qualitatively evaluating the fatigue life of a turbine blade is described. The gas turbine blade is to be within its fatigue life if the creep elongation strain in the longitudinal direction of the turbine blade is less than 0.5% of an initial length. Moreover, a gas turbine blade creep elongation strain measuring apparatus which comprises a first fixed end, a second fixed end and a dial gauge. A dimension in the longitudinal direction is stamped on the surface of a turbine blade.
SUMMARY OF INVENTION
It is an objective of the present invention to provide an advantageous elongated member of a wind turbine. It is another objective of the present invention to provide an advantageous wind turbine rotor blade. A final objective of the present invention is to provide an advantageous tower of a wind turbine.
The first objective is solved by an elongated member of a wind turbine. The second objective is solved by a wind turbine rotor blade and the third objective is solved by a tower of a wind turbine. The depending claims define further developments of the invention.
The inventive elongated member of a wind turbine is potentially subject to strain. It comprises a sensor unit for determining the deflection and/or strain of the elongated member between a first point and a second point, which are assigned to the same side of the elongated member. The sensor unit comprises a proximity sensor for determining the distance between the second point and a third point. The third point is connected to the first point by an inflexible or stiff support. The distance between the first point and the third point is considerably longer than the distance between the second point and the third point.
The sensor unit can comprise a compressible and/or stretchable element located between the second point and the third point.
The invention is based on the observation that an elongated member of a wind turbine deflects when it is affected by strain. Due to the deflection also the distance between two distant points of the affected elongated member changes. The changed distance can be used as a measure of the deflection and/or as a measure of the strain.
The use of an inflexible support has the advantage that only a relatively small distance between the second point and a third point needs to be measured when the distance between the first and second point changes since the third point has a fixed and known relationship to the first point due to the inflexible support. The relatively small distance to be measured increases the accuracy and the robustness of the determination of the deflection and/or the strain.
The determination or measurement of the distance between the second and third points can especially be done by means of an acoustic, magnetic, electromagnetic, capacitive or inductive measurement. Preferably, the distance between the second point and the third point can be determined by means of a laser range sensor.
In order to further increase the accuracy in determining the deflection and/or strain of the elongated member of the wind turbine the method can be performed at least two sides of the elongated member. The sides can be perpendicular or parallel and/or opposite to each other. Then the distance between second points and third points which are assigned to a same side of the elongated member may be separately determined for each of the sides.
For example, the determination of the distance at two parallel and opposite sides of the elongated member which is subject to bending provides two different results, which represent compression and stretch. At one side, the distance between two distant points, i.e. the first and the second point, assigned to this side decreases compared to the distance between these points when the elongated member is not subject to bending. The decreased distance is due to a compression of this side. Because of the inflexible or stiff support between the first point and a third point, the decreased distance can be measured with high accuracy between the second and the third point. At the second side, the distance between two distant points, i.e. the first and the second point, assigned to this side increases due to a stretch of this side. This increased distance can be measured between the second and the third point assigned to this side.
Furthermore, the distance can be determined at sides which run perpendicular to each other. This provides information about the deflection in perpendicular directions. Of course, to increase the accuracy the distance at two or more parallel and at two or more opposite sides of the affected elongated member can be measured to determine deflection and/or the strain in each direction.
The described method can preferably be applied to wind turbine rotor blades or wind turbine towers. In the case of an application in a wind rotor blade the results regarding the deflection and the strain acting on the rotor blade may be used as feedback for cyclic pitch control or for individual pitch control in general. Individual pitch control denotes pitch control where the blades are pitched more or less independently of each other. Pitch control schemes are often used to reduce the loads acting on the blades and hence the resulting deflections and strains.
The sensor may be located at the second point or at the third point. Moreover, the compressible and/or stretchable element may comprise a hollow space extending from the second point to the third point. This makes it possible to measure the distance inside the hollow space which reduces environmental influences. The compressible and/or stretchable element may, for example, be a rubber support or a telescope unit. If the support is designed as a telescope it is advantageous when the telescope has low friction.
The proximity sensor can, for example, be an acoustic sensor, a magnetic sensor, an electromagnetic sensor, a capacitive sensor or an inductive field effect sensor. Preferably, the proximity sensor can be a laser range sensor.
The inventive wind turbine rotor blade comprises an inventive elongated member as previously described. Advantageously, the elongated member can comprise at least two sensor units. The at least two sensor units can be arranged such that their inflexible supports extend parallel to each other at different sides of the elongated member. Alternatively or additionally, sensor units can also be arranged such that their inflexible supports extend perpendicular to each other. The rotor blade may comprise a blade root and a shoulder and the sensor unit can preferably be located between the blade root and the shoulder. A positioning of the sensor unit near the blade root is advantageous because the moment due to the bending is mainly acting at the rotor blade near the blade root.
The sensor unit can generally be applied in connection with cyclic pitch control and for individual pitch controllers. Individual pitch control denotes pitch control where the blades are pitched more or less independently of each other. Moreover, the determination of the deflection and/or the strain induced to the blade root may provide accuracy in blade root sidewise moment signals that makes stall detection, based on lift/drag calculation, possible.
The inventive tower of a wind turbine comprises an inventive elongated member as previously described. Preferably the inventive elongated member of the wind turbine tower with the sensor unit is located near the tower bottom or near the tower top. What was said with respect to parallel and perpendicular extension of the inflexible support members of two or more sensor units in wind turbine blades is also applicable to wind turbine towers.
As the deflection and/or the strain is determined by means of any of the inventive devices, the obtained result has the lowing qualities: the measurement is significantly more robust regarding local geometry. Furthermore, the measurement is more robust due to large dynamic range in the proximity measurement.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features, properties and advantages of the present invention will become clear from the following description of an embodiment in conjunction with the accompanying drawings.
FIG. 1 schematically shows an elongated member of a wind turbine which is not deflected in a sectional view.
FIG. 2 schematically shows a part of a wind turbine rotor blade in a sectional view.
FIG. 3 schematically shows the sensor unit.
FIG. 4 schematically shows a view along the direction IV-IV in FIG. 3 .
DETAILED DESCRIPTION OF INVENTION
An embodiment of the present invention will now be described with reference to FIGS. 1 to 4 . At first, the general principle or the idea of the invention will be explained with reference to FIG. 1 . FIG. 1 schematically shows an elongated member of a wind turbine 15 which is not deflected in a sectional view. The elongated member 15 comprises two distant points, a first point 16 and a second point 17 . It further comprises a third point 18 which is connected to the first point 16 by means of an elongated inflexible or stiff support 5 , for example a stiff rod. In FIG. 1 the inflexible support 5 extends parallel to the elongated member 15 . Moreover, the third point 18 is located between the first point 16 and the second point 17 . The distance between the first point 16 and the third point 18 is much longer than the distance between the second point 17 and the third point 18 .
In case of a deflection of the elongated member 15 , the distance between the first point 16 and the second point 17 changes and therefore also the distance between the second point 17 and the third point 18 changes. To determine the deflection the distance between the second point 17 and the third point 18 can be determined or measured, preferably by a laser range sensor or any other proximity gage. The used proximity sensor can be located at the second point 17 or at the third point 18 . With the invention, only the relatively small distance between the second point 17 and the third point 18 has to be determined, which increases the accuracy of the measurement.
FIG. 2 schematically shows a part of the wind turbine rotor blade 1 in a sectional view. The rotor blade 1 comprises a blade root 8 , a leading edge 11 , a trailing edge 12 and a shoulder 10 which is the point of the blade's greatest width. The blade 1 is typically mounted to a rotor hub at the blade root 8 . The centreline 13 (also called span) of the rotor blade 1 extend from the centre of the blade root 8 to the tip of the blade which is not shown in FIG. 2 . The so called chord 14 characterises the width of the blade 1 perpendicular to the centreline 13 . The region where the chord 14 reaches its highest value is called the shoulder 10 of the blade 1 , i.e. the location of the blade's greatest width. The trailing edge 12 connects the blade root 8 via the shoulder 10 to the tip of the blade 1 . The leading edge 11 is the side which connects the blade root 8 to the tip and extends opposite the trailing edge 12 as seen in a chordwise direction.
The wind turbine blade 1 is hollow inside. It further comprises two sensor units inside its hollow body for determining the deflection of the blade 1 . One sensor unit is mounted with the stiff support 5 extending along the leading edge 11 near the blade root 8 while the other sensor unit is mounted with the stiff support 5 extending along the trailing edge 12 near the blade root 8 .
Each sensor unit for the determination of the deflection near the blade root 8 comprises an inflexible or stiff support 5 , a proximity sensor 4 , a compressible element 3 and a reference fitting 2 . The reference fitting 2 comprises the second point 17 . One end of the inflexible support 5 is fixed to the blade root 8 by a fixation 6 on which the first point 16 is located. The proximity sensor 4 is mounted to the other end of the inflexible support 5 and provides the third point 18 . The proximity sensor 4 is further connected to the reference fitting 2 via the compressible and/or stretchable element 3 , which is, in the present embodiment, a rubber support in form of a rubber sleeve. Alternatively, the proximity sensor 4 may be mounted to the reference fitting 2 and may provide the second point 17 . The third point 18 would then be provided by the loose end of the inflexible support 5 .
In the present embodiment the sensor 4 is a proximity gage, for instance a laser range sensor. Generally, the proximity measurement may be based on acoustic, magnetic, electromagnetic, capacitive or inductive field effects. The proximity sensor 4 in the present embodiment measures or determines the distance between the proximity sensor 4 , which defines the third point 18 , and the reference fitting 2 , which defines the second point 17 .
In conjunction with the known length of the inflexible support 5 the measured distance between the proximity sensor 4 and the reference fitting 2 can be used to provide a measure for, or to determine, the distance between the second point 17 and the first point 16 , which corresponds to the difference between the reference fitting 2 and the fixation 6 of the inflexible support 5 to the blade root 8 . This means that the distance between two distant points, namely the first point 16 and the second point 17 , is determined and provides information about the deflection of the elongated member between these two points.
When no deflection occurs, the inflexible support 5 of one sensor unit of the two sensor units is parallel to the leading edge 11 and the inflexible support 5 of the other sensor unit of the two sensor units is parallel to the trailing edge 12 . In the present embodiment the leading edge 11 and the trailing edge 12 are parallel to each other near the blade root 8 . In the case of a deflection of the turbine blade, the leading edge 11 and the trailing edge 12 deflect. This results in a change of distance between the reference fitting 2 and the fixation 6 of the respective sensor unit. For instance, the distance between the first point 16 and the second point 17 of the sensor unit which is parallel to the leading edge 11 increases and the distance between the first point 16 and the second point 17 of the sensor unit which is parallel to the trailing edge 12 decreases when the rotor blade is deflected towards the trailing edge.
Due of the fact that the distance between the proximity sensor 4 and the fixation 6 , which is the distance between the second point 17 and the first point 16 , cannot change because of the inflexibleness of the inflexible support 5 , the changed distance between the fixation 6 and the reference fitting 2 occurs as a change of the distance between the proximity sensor 4 and the reference fitting 2 , which is the distance between the second point 17 and the third point 18 . This changed distance is measured by the proximity sensor 4 and can be used to determine the deflection of the rotor blade 1 and/or the strain acting on the rotor blade 1 .
FIG. 3 schematically shows one of the sensor units. The sensor unit comprises two mounting brackets 7 , 27 an inflexible support 5 , a sensor 4 and a rubber sleeve as a compressible and/or stretchable element 3 . The left mounting bracket 7 in FIG. 3 can be used to fix the sensor unit to the reference fitting 2 and provides the second point 17 . The right mounting bracket 27 in FIG. 3 can be used to mount the sensor unit to the fixation 6 and provides the first point 16 . Alternatively, the right mounting bracket 27 may be fixed to the reference fitting 2 and the left mounting bracket 7 to the fixation 6 , which would locate the sensor 4 close to the blade root 8 .
One end of the inflexible support 5 is fixed to the right mounting bracket 27 , which corresponds to the first point 16 . The proximity sensor 4 , which is a laser range sensor in the present embodiment, is mounted to the other end of the inflexible support 5 and provides the third point 18 . In FIG. 3 the rubber sleeve 3 is placed between the proximity sensor 4 and the left mounting bracket 7 , which corresponds to the second point 17 . Instead of a rubber sleeve a different rubber support or a telescope unit with low friction may be used as well.
A sectional view along the direction indicated by line IV-IV in FIG. 3 is shown in FIG. 4 . FIG. 4 schematically shows the cross-section of the rubber sleeve 3 of the present embodiment. The rubber sleeve 3 has a circular cross-section with a hollow space 9 in its centre. One can further see in the background of FIG. 4 the proximity sensor 4 and the corresponding third point 18 , which is schematically represented by a surface of the proximity sensor 4 . Advantageously, the proximity measurement is performed inside the hollow space 9 of the compressible element 3 . This allows an undisturbed measurement by avoiding environmental influences.
Generally the number of used sensor units can vary depending on the characteristics of the deflection or the strain which shall be measured. In the present embodiment the sensor setup measures edge-wise strains which allow for determining edge-wise moments. Furthermore, flap-wise moments can be measured by similar sensor units rotated by 90°, for example parallel to the chord 14 . If sensor units in both orientations are present, this would provide a means for determining moments about two axes. Of course, it is also possible to use only one sensor unit for determining the deflection and/or the strain and/or the moments about each axis.
The described sensor unit may also be applied to other parts of a wind turbine rotor blade or to the tower of a wind turbine, for instance at the tower bottom or the tower top.
Compared to the cited state of the art the present invention provides a cheap possibility to determine the deflection and/or the strain of an elongated member of a wind turbine because the described sensor unit can easily be mounted at each desired position. Furthermore, the present invention allows for measurements with a very high accuracy because, in contrast to the cited state of the art, the deflection or the strain is determined where the deflection or the strain occurs, that is in the vicinity of a side of the elongated member which is subject to strain and not near the centreline of a hollow body of the elongated member as it is proposed in U.S. Pat. No. 7,059,822 B2. | An elongated member of a wind turbine is disclosed which is potentially subject to strain and which comprises a sensor unit for determining the deflection and/or strain of the elongated member between a first point and a second point, which are assigned to the same side of the elongated member, and the sensor unit comprises a proximity sensor for determining the distance between the second point and a third point, the third point being connected to the first point by an inflexible support, the distance between the first point and the third point being considerably longer than the distance between the second point and the third point, wherein the sensor unit comprises a compressible and/or stretchable element located between the second point and the third point. Moreover, a wind turbine rotor blade and a tower of a wind turbine, each comprising a previously described elongated member, are disclosed. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is relating to a method for manufacturing a semiconductor device, particularly to a method for manufacturing, for example, a double diffused MOSFET (referred to hereinafter as a DMOS).
2. Description of the Related Art
A vertical type DMOS by which a low ON resistance and high withstanding voltage can be comparatively easily obtained has been generally used as an element in the construction of, for example, a power MOSFET. In this element, a plurality of unit cell transistors each having a size of several tens of μm are connected in parallel to form one element.
Hereafter, a current method for manufacturing the vertical type DMOS is explained with reference to FIG. 2.
First, as shown in FIG. 2, (a), an N - -type epitaxial layer 22 is formed on a main surface of an N + -type Si substrate 21 by an epitaxial growth process and a gate oxide film 23 consisting of SiO 2 is fabricated by oxidizing a main surface of the N - -type epitaxial layer 22 with heat. Then, as shown in FIG. 2(b), a polycrystalline silicon layer 24 is deposited on a surface of the gate oxide film 23 by a CVD (Chemical Vapor Deposition) method.
Thereafter, as shown in FIG. 2(c), an opening is provided at a desired region of the polycrystalline silicon layer 24 by an etching method utilizing reactive ions (referred to hereinafter as RIE) and a P-type well region 27 is formed by implanting P-type impurities by ion implantation, using the residual polycrystalline silicon layer 24 as a mask.
A resist 26a is then formed on a desired region in the above opening by a photo etching method, and an N + -type diffusion region 28 is formed in the P-type well region 27 by implanting N-type impurities by ion implantation, using the residual polycrystalline silicon layer 24 and the resist 26a as a mask.
Then, as shown in FIG. 2(d), the resist 26a is removed and an insulating layer 25 consisting of SiO 2 is deposited on a whole surface of the device by a CVD method.
Finally, as shown in FIG. 2(e), a resist 26b is formed on a desired region of said insulating layer 25 by photo etching and the insulating layer 25 and the gate oxide film 23 are etched using the resist 26b as a mask, and a line means of, for example, Al (not show), is provided in electrical contact with the P-type well region 27 and N-type diffusion region 28.
The vertical type DMOS thus produced comprises an N + -type Si substrate 21 and an N - -type epitaxial layer 22 as a drain region, an N + -type diffusion region 28 as a source region, a polycrystalline silicon layer 24 as a gate electrode and a P-type well region 27 as a channel region.
When the ON resistance of the power MOSFET is reduced, the current drive performance is increased, and thus the size of the device can be reduced. Accordingly, the ON resistance should be made as low as possible, to meet present requirement for minimizing a chip size and therefore, a number of unit cells provided in the same chip size must be increased, to widen a total channel width thereof by minimizing the size of an element thereof, and thus reduce the size of the unit cell.
Especially, a great effect can be obtained when a withstand voltage of less than 100 V is used, as this enables the extent of a contribution of the channel width to the ON resistance to be improved.
As mentioned above, to make the ON resistance low, preferably the size of the unit cell is reduced.
But, in the current method, in each step, for example, when the N + -type diffusion region 28 is formed inside the P-type well region 27 as explained in FIG. 2(c) and when the opening is formed in the insulating layer 25 and said gate oxide film 23 to provide an electrical connection among the P-type well region 27, N-type diffusion region 28, and wiring means, a photo etching method is applied to the resists 26a and 26b and thus there is a great possibility that deviations between the position of the glass mask and that of the element will occur, and accordingly, marginal portions of about ±3 μm are usually required when designing a unit cell size if a 1:1 projection exposure device is used, and consequently, the minimum size of the unit cell is limited to about 25 to 30 μm.
On the other hand, the unit cell size can be reduced to around 15 to 20 μm by using a reduction projecting exposure device such as a 1:5 Stepper (Direct Stepping on Wafer), but in such a case, a problem arises in that the cost of production of an element will be increased.
SUMMARY OF THE INVENTION
Accordingly, the object of the present invention is to provide a method for manufacturing a semiconductor device having a low ON resistance and enabling a reduction of the size of the unit cell thereof, without receiving any affects from machine performance of an exposure device.
These and other advantages of the present invention will be made apparent by the following explanation, with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1(a) to (j) are sectional views sequentially explaining the configuration of the device of this invention at each process step thereof;
FIGS. 2(a) to (f) are sectional views sequentially explaining the configuration of the device produced by a conventional method at each process step thereof;
FIG. 3 shows a comparison between the unit cell size of Example 1 of this invention and that of the prior art;
FIGS. 4(a) to (b) are sectional views explaining the process of Example 2 of this invention;
FIGS. 5(a) to (c) are sectional views explaining the process of Example 3 of this invention;
FIGS. 6(a) to (c) are sectional views explaining the process of Example 4 of this invention; and,
FIGS. 7(a) to (e) are sectional views explaining the process of Example 5 of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
To attain the object of this invention, a method for manufacturing a semiconductor device basically comprises the steps of forming a first conductive type epitaxial layer having a low impurity concentration on one main surface of a substrate; forming a first insulating layer on one main surface of the epitaxial layer and subsequently forming a gate electrode layer and a second insulating layer successively on a region of the first insulating layer; forming a second conductive type region and a first conductive type region having a width narrower than that of the second conductive type region by doping impurities into the epitaxial layer, while utilizing the second insulating layer as a mask; forming a side wall of an insulating material on at least a side portion of the gate electrode; forming a conductive portion penetrating the first conductive type region and extending into the second conductive type region, while utilizing the second insulating layer and the side wall as mask; forming a first electrode electrically connected to the first conductive type region and the second conductive type region through the conductive portion on a main surface of the epitaxial layer; and finally forming a second electrode on an opposite side of a main surface of said substrate.
According to this invention, a photo etching operation is not required when the first conductive type region is formed inside the second conductive type region and when an electrical connection is formed among the second conductive type region, first conductive type region, and a first electrode, because the conductive portion is formed by a self-alignment process using the second insulating layer and the side wall as a mask, and therefore, a marginal portion for compensating for any positional deviation in the current method is not required, and thus the unit cell size can be reduced to an extent corresponding to the omitted marginal portion. In this invention, the doping method includes a diffusing method and an ion implantation method.
EXAMPLES
Examples of the present invention will be now described with reference to the drawings.
Example 1
FIGS. 1(a) to (j) are sectional views sequentially explaining the configuration of the device in this invention at each process step thereof.
First, as shown in FIG. 1(a), an N - -type epitaxial layer 2 having a low impurity concentration is formed on a main surface of an N + -type Si substrate 1 by an epitaxial growth process, to form a drain region consisting of the N + -type Si substrate 1 and N - -type epitaxial layer 2.
Then a gate oxide film 3 consisting of SiO 2 is formed on a main surface of the N - -type epitaxial layer 2 by oxidizing that surface by a wet HCL method, at a temperature of 875° C. for 60 minutes.
Then, as shown in FIG. 1(b), a polycrystalline silicon layer 4, which is used as a gate electrode, and an insulating layer 5, are successively deposited on a surface of the gate oxide film 3 by a CVD method.
Thereafter, as shown in FIG. 1(c), predetermined portions of the polycrystalline silicon layer 4 and the insulating layer 5 are removed by an RIE method to make an opening 6, a P-type well region 7 is then formed by doping P-type impurities such as B (boron) by ion implantation in a self alignment manner, for example, using the insulating layer 5 as a mask, and then an N + -type diffusion region 8 which is used as a source region, is formed in the P-type well region 7 by doping N-type impurities such as As (arsenic) or P (phosphorous) by ion implantation at a relatively high concentration.
Subsequently, as shown in FIG. 1(d), an insulating layer 9 of SiO 2 is deposited on a whole surface of the insulating layer 5 and the gate oxide film 3 by a CVD method. Note, in this example, the TEOS (Tetraethoxysilane) CVD method may be applied at the step shown in FIG. 1(d) of forming the insulating layer 9, since the use of the TEOS CVD method ensures that insulating layer 9 has a uniform film characteristic in which both a vertical and a lateral film thicknesses thereof are equal to each other.
Then as shown in FIG. 1(e), the insulating layer 9 is etched by RIE, until only a side wall 9a remains on a side surface of the polycrystalline silicon layer 4 and the insulating layer 5. This etching operation may be carried out on the gate oxide film 3 at the same time.
As shown in FIG. 1(f), a concave portion 10 is etched into the N + -type diffusion region 8 and the bottom portion thereof is extended into the P-type well region 7 by an RIE method in the self alignment manner, utilizing the insulating layer 5 and the side wall 9a as a mask. This concave portion is one kind of a conductive portion defined in this invention and the conductive portion further includes a portion consisting of a second conductive type diffusing region or a metallic compound.
Therefore, as shown in FIG. 1(g), an overetching operation is carried out over the surface of the insulating layer 5, the side wall 9a, and the gate oxide film 3, using ammonium fluoride, to expose a part of a main surface of the N + -type diffusion region 8.
Then, as shown in FIG. 1(h), an aluminum line 11 is formed by a sputtering method, so that the line 11 is connected to both the P-type well region and the N + -type diffusion region 8, and then, as shown in FIG. 1(i), a passivation film 12 of SiN is formed over the aluminum line 11 (Al) wiring by a plasma CVD method.
Finally, as shown in FIG. 1(j), thin films of Ti, Ni, and Au, respectively, are formed sequentially on the opposite main surface of the N + -type Si substrate 1 by a sputtering method, to make a drain electrode 13.
According to the present invention, as explained in FIG. 1(c), when forming the N + -type diffusion region 8 in the P-type well region 7, the N + -type diffusion region 8 need not be formed in a shape such as shown in the prior art partition of FIG. 3 plane view but can be formed over a whole area surrounded by the insulating layer 5, and the resists need not be formed by a photo etching method.
Further, as explained in FIG. 1(f), the concave portion 10 is formed by an RIE method in a self alignment manner, using the side wall 9a and the insulating layer 5 as a mask but without using the photo etching method, and the Al line 11 is formed in the concave portion 10 to form a electrical connection between the concave portion 10 and the N + -type diffusion region 8 in the P-type well region 7.
Consequently, in the method of this example, the marginal portion usually required for compensating the positional deviation generally occurring in a conventional type 1:1 projection exposure device during photo etching can be omitted, and accordingly, a reduction of the unit cell size becomes possible.
FIG. 3 shows a comparison of the difference between the current unit cell produced by the conventional method and that of this invention. The Figure shows a plane view of an element of a unit cell in the upper portion thereof, and a cross sectional view of an element of an unit cell in the bottom portion thereof.
As shown in FIG. 3, one side of the conventional unit cell has a length of 25 μm, reducing the unit area thereof to 25 2 μm 2 , and one side of the channel width of the conventional unit cell is 15 μm, and thus the channel width thereof per unit cell is 15×4 μm.
Conversely in the unit cell of Example 1 of this invention, the area of the unit cell and the channel width per unit cell thereof are 15 2 μm and 9×4 μm, respectively.
Accordingly, when calculating the ratio of the channel width to the area in a chip having the same value, the ratio of this invention is 167%, taking the value of the ratio of the conventional unit cell as being 100%, and thus it is clear that the channel width of the present invention has been remarkably extended.
Therefore, the ON resistance of Example 1 will be about 60% when the value of the same resistance of the conventional unit cell is made 100%, and thus a remarkable effect whereby the ON resistance is reduced by about 40% is realized.
According to experiments by the present inventors, it became apparent that As is preferable to P as the impurity used in ion implantation in the step shown in FIG. 1(c) for forming the N + -type diffusion region 8. This was found to be because the diffusion coefficient of As is smaller than that of P, and therefore, when P is used in this step, the depth of the N + -type diffusion region 8 becomes about 0.3 μm, but this depth becomes about 0.1 μm when As is used, and thus the use of As reduces the depth of the concave portion 10.
The Si etching process usually take much time, but this time is shortened by the above process, and thus the roughness of the surface is reduced.
Although the depth of the diffusion region is made shallower when As is used, the contact resistance to the Al electrode 11 is increased. According to the present invention however, this contact resistance is reduced by using the over etching method in the step shown in FIG. 1(g).
Example 2
Next, a second example of the present invention will be explained with reference to the sectional view shown in the FIG. 4.
Note, in Example 2, the same steps as shown in FIGS. 1(a) to (e) and FIGS. 1(g) to (j) of Example 1 can be applied, and therefore, the components of FIG. 4 similar to those of FIG. 1 are given the same reference numbers as in FIG. 1, and an explanation thereof omitted. Further, FIG. 4(a) corresponds to FIG. 1(f) and FIG. 4(b) is a sectional view of the final product of Example 2 corresponding to FIG. 1(j).
The difference between Example 2 and Example 1 is that, as shown in the FIG. 4(a), a P + -type diffusion region 10a is formed by implanting P-type impurities by ion implantation at a high concentration in a self alignment manner, utilizing the side wall 9a and the insulating layer 5 as a mask, and the electrical connection between the Al line 11 and the P-type well region 7 is formed through the P + -type diffusion region 10a. This P + -type diffusion region 10a is an another kind of a conductive portion of this invention.
In Example the step of forming the P + -type diffusion region 10a may be carried out before etching the gate oxide film 3.
Example 3
Next, a third example of the present invention will be explained with reference to the sectional view shown in the FIG. 5.
Note, in Example 3, the same steps as shown in FIGS. 1(a) to (e) of Example 1 can be applied, and therefore, the components of FIG. 5 similar to those of FIG. 1 are given the same reference numbers as in FIG. 1, and an explanation thereof omitted.
In Example 3 the step shown in FIG. 1(e) is followed by the step of depositing the Al wiring 11 by a sputtering method to form an electrical connection with the N + -type diffusion region 8, as shown in FIG. 5(a), the step of forming a compound of Al and/or Si by sintering the portion under a forming gas atmosphere at a temperature of abut 400° to 500° C., which conditions are very severe compared with the normal conditions, to form an Al silicide region 10b, the bottom of which reaches the P-type well region 7, as shown in FIG. 5 (b), and the step of forming a passivation film 12 and a drain electrode 13 by the same method as in Example 1 as shown in FIG. 5(c).
In Example 3, when the sintering operation is carried out, the Al silicide region 10b can be selectively formed inside the region surrounded by the side wall 9a, since the side wall 9a and the insulating layer 5 act as masks, and further, the electrical connection between the Al line 11, the P-type well region 7, and the N + -type diffusion region 8 is formed through the Al silicide region 10b, and thus Example 3 realizes the same effect as obtained in Examples 1 and 2.
Further, in Example 3, neither etching nor ion implantation are used to form the Al silicide region 10b, but instead the conditions therefor are previously delineated, and thus the manufacturing process can be simplified.
Although in Examples 1 and 2, it is immaterial whether the material used for the Al for the line includes Si or the like, in Example 3, preferably a pure Al, without the inclusion of Si or the like, is used.
Moreover, before forming the Al line 11, when the Al silicide region 10b is reduced to a solid epitaxial region which is grown with amorphous Si contained in the Al-Si by implanting Si + ions by ion implanting, a stable contact region having a lower ohmic resistance than that of usual Al--Ai, and preventing any diffusion of Al into Si, can be obtained. The Al silicide, a metallic compound is an another kind of conductive portion of this invention.
Example 4
Next, a fourth example of the present invention will be explained with reference to the sectional view shown in the FIG. 6.
Note, in Example 4, the same steps as shown in FIGS. 1(a) to (e) of Example 1 can be be applied and therefore the components of FIG. 6 similar to those of FIG. 1 are given the same reference numbers as in FIG. 1, and an explanation thereof omitted.
In Example 4, the step shown in FIG. 1(e) is followed by the step of depositing a metallic film 30 made of Ti, Wo, Mo, or the like by a sputtering method or an evaporation method, form an electrical connection with the N + -type diffusion region 8, as shown in FIG. 6(a), the step of forming a metal silicide region 10c, which is a compound of metal and Si, only in a region surrounded by the side wall 9a by the sintering operation used in Example 3, a step of removing the metallic film 30 by etching with H 2 SO 4 , HNO 3 or the like, as shown in FIG. 6(b), and a step of forming an Al wiring 11, a passivation film 12, and a drain electrode 13 by the same method as in Example 1, as shown in FIG. 6(c) after the etching of the side wall 9a is carried out in the same manner as described in Example 1.
According to Example 4, as Example 3, an electrical connection between the Al line 11 and the P-type well region 7 through the metal silicide region 10c can be obtained, and thus the same effect realized in the previous Examples is obtained.
In Example 4, the control of the metal silicide region 10c can be increased by selecting a metallic material having a lower reactivity to Si than to Al as the material of the metallic film 30. The metal silicide region 10c is also another kind of conductive portion of this invention.
Example 5
Next, a fifth example of the present invention will be explained with reference to the sectional view shown in the FIG. 7.
Note, in Example 5, the same steps as shown in FIGS. 1(a) to (f) of Example 1 can be applied, and therefore, the components of FIG. 7 similar to those of FIG. 1 are given the same references numbers as in FIG. 1, and an explanation thereof omitted.
Further note, FIG. 7(a) shows a characteristic feature of Example 5 and FIGS. 7(b) to (l) corresponding to the FIGS. 1 (g) to (j), respectively.
In Example 5, after the step shown in FIG. 1(f), separate ion implanting operation is added as shown in FIG. 7(a).
Namely, after the concave portion 10 is formed by an RIE method in a self alignment manner utilizing the insulating layer 5 and the side wall 9a as a mask, as show in FIG. 1(f), in Example 5, a further ion implanting operation is carried out to implant the P-type impurities such as B (boron), GA (gallium), or In (indium) in a self alignment manner, using the insulating layer 5 and the side wall 9a as a mask, to form a P + -region 10d in the P-type well region 7 as shown in FIG. 7(a).
In Example 5, the steps following the step mentioned above are the same as that of Example 1, with the exception of the adding of the P + -region 10d in FIGS. 7(b) to (e).
In Example 5, the contact between the P-type well region 7 and the Al line 11 is remarkably improved.
The present invention has been described with reference to 5 examples, but this invention is not restricted to these Examples and various modifications thereof are possible within the scope of the concept of this invention. For example, in the Examples above an N-type DMOS is used but obviously a P-type DMOS also can be used in this invention.
Further the same effect can be obtained even when the type of the substrate of the semiconductor is reversed, to make a MOSFET having a modulation conductivity, and further, in the Example 5 mentioned above, a device having a two layer construction comprising an N + -type Si substrate 1 and an N - -type epitaxial layer 2 is used, but a device having three layers or more may be used in this invention.
EFFECT OF THE INVENTION
As described above, according to this invention, photo etching is not required when forming the first conductive type region inside the second coductive type region and when forming an electrical connection among the second conductive type region, the first conductive type region, and a first electrode, since a conductive portion is formed by self alignment using the second insulating layer and the side wall as a mask, and therefore, the margin required for compensating positional deviation in the conventional method can be omitted, and thus the unit cell size can be reduced to an extent corresponding to the omitted margin.
Also a superior effect is realized in that the number of unit cell transistors fabricated in the same chip can be increased and the total channel width is also extended, and thus a semiconductor device having a low ON resistance can be produced. | A method for manufacturing a DMOS which comprises forming a first conductive type layer on a substrate, forming a gate oxide layer thereon, forming a gate electrode layer and a second insulating layer successively on the gate oxide layer, forming a second conductive type body region and a first conductive type source region having a narrower width by implanting impurities utilizing the second insulating layer as a mask, forming a side wall spacer of an insulating material on at least a side portion of the gate electrode, forming a conductive passage penetrating the source region and extending into the body region while utilizing the second insulating layer and the side wall spacer as mask, optionally implanting the exposed body region, further excessively etching the sidewall spacer, the masking layer overlying the gate, and the gate oxide prior to providing an electrode connecting the source and body regions. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The disclosed invention generally relates to a tray assembly. More particularly, the disclosed invention relates to a multi-purpose tray assembly for use in combination with variable level surfacing such as inclined, stepped, or level support surfaces.
[0003] 2. Description of the Prior Art
[0004] U.S. Pat. No. 5,249,397, which issued to Monaco ('397 Patent), and U.S. Pat. No. 5,913,782, which issued to Monaco et al. ('782 Patent), discloses a Knockdown Roof Platform for use on an Inclined Roof. The '397 Patent and the '782 Patent describe certain knockdown platforms for use on an inclined surface. The platforms may be said to comprise a table structure having an upper table top with a plurality of indentations and openings for containment of a variety of objects. The table structure has a hollowed area on its underside. An upright leg structure is positioned at one end of the table structure. A hinge connects the table structure and the upright leg structure in assembly together in the hollowed area. Collapsible locking brackets further secure the table structure and the upright leg structure in assembly. The collapsible locking brackets are adjustable so as to secure the table structure and the upright leg structure at right angles. The collapsible locking bracket is releasable enabling the table structure and the upright leg structure to be pivoted on the hinge located interior to the hollowed area on the underside of the table structure. The collapsible locking bracket allows for the collapsing of the table structure and the upright leg structure out of right angle relation relative to one another and into a collapsed storage position where the table structure and the upright leg structure extend generally in a parallel relation.
SUMMARY OF THE INVENTION
[0005] The present invention provides a multiple purpose tray assembly for inclined or level surfaces, which tray assembly may be used in tandem with identical embodiments of the tray assembly for forming larger, linked tray assemblages. In this last regard, it is contemplated that the tray assembly(ies) may be coupled to one another is side-by-side relation either by certain hardware based fastening means or by tongue and groove type fastening means.
[0006] The tray assembly may comprise a plurality of legs, which are stowable in a primary tray structure when not being used to elevate the tray structure above a support surface. When used to elevate the primary tray structure above variable level support surfacing, such as stepped, inclined, or horizontal support surfacing, the legs may each be adjusted relative to the primary tray structure for properly maintaining a horizontal tray configuration relative to the support surfacing.
[0007] To achieve these and other readily observable objectives, the present invention specification describes a tray assembly for use in combination with variable level support surfacing so as to provide a horizontal tray. The tray assembly according to the present invention comprises a first or primary tray structure and at least one pair of tray support legs. The primary tray structure has an upper tray surface, a lower tray surface, opposed leg-receiving slots extending intermediate the upper to lower tray surfaces, and opposed leg-receiving apertures extending from the upper to lower tray surfaces. The tray support legs are removably receivable in the tray-receiving slots for stowage, and are removably receivable in the leg-receiving apertures for supporting the primary tray structure in horizontal spaced relation relative to a support surface.
[0008] The leg-receiving apertures and tray support legs comprise certain means for selectively and orthogonally varying the position of the respective tray support legs relative to the respective leg-receiving apertures, which means enhance a user's ability to use the tray in combination with variable level surfacing. Said means may be preferably and cooperatively defined by aperture tabs formed within the leg-receiving apertures and tab-receiving channels formed within the tray support legs. The aperture tabs are receivable in the tab-receiving grooves for adjusting the position of the tray support legs relative to the leg-receiving apertures.
[0009] The tab-receiving channels each comprise a vertical groove portion and a series of horizontal groove portions continuous or contiguous with the vertical groove portion. The vertical groove portion enables the user to orthogonally adjust the position of the respective tray support legs relative to the leg-receiving apertures, and the horizontal groove portions enable the user to orthogonally fix the position of the respective tray support legs relative to the leg-receiving apertures.
[0010] Each leg-receiving aperture may preferably comprise opposed aperture tabs, and each tray support leg may preferably comprise opposed set of tab-receiving channels. It is contemplated that the opposed aperture tabs and opposed sets of tab-receiving channels may well function to enhance stability of the tray support legs as removably received in the leg-receiving apertures. As earlier stated, the tray assembly may further comprise certain means for coupling a second tray structure to the first tray structure, which second tray structure is substantially identical to the first or primary tray structure.
[0011] Certain matter receiving pockets may be formed within the primary tray structure(s) and thus the tray can be used in painting, plumbing, electrical, or roofing applications. The tray structure may be used by a worker so that he or she may place tools or hardware in the pockets so as to organize one's building materials and supplies. Other objects of the present invention, as well as particular features, elements, and advantages thereof, will be elucidated or become apparent from, the following description and the accompanying drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Other features of our invention will become more evident from a consideration of the following brief description of patent drawings:
[0013] FIG. 1 is a top perspective view a tray assembly according to the present invention with four tray-supporting legs received in four, corner-located leg-receiving apertures for supporting the tray assembly above a horizontal support surface.
[0014] FIG. 2 is a top perspective view of a primary tray structure and a single leg exploded therefrom adjacent a single leg-receiving aperture.
[0015] FIG. 3 is a top plan view of the primary tray structure of the tray assembly according to the present invention.
[0016] FIG. 4 is a bottom plan view of the primary tray structure of the tray assembly according to the present invention.
[0017] FIG. 5 is a top perspective view of two substantially identical tray assemblies attached to one another is side-by-side relation.
[0018] FIG. 6 is an end view of the tray assembly showing the primary tray structure in a first elevated position.
[0019] FIG. 7 is a side view of the tray assembly showing the primary tray structure in a first elevated position.
[0020] FIG. 8 is an end view of the tray assembly showing the primary tray structure in a second elevated position.
[0021] FIG. 9 is a side view of the tray assembly showing the primary tray structure in a second elevated position.
[0022] FIG. 10 is a top perspective view of the tray assembly with two tray-supporting legs received in two leg-receiving apertures and positioned atop an inclined tray support surface such that the primary tray structure is maintained in a horizontal orientation.
[0023] FIG. 11 is a top perspective view of the tray assembly with two tray-supporting legs received in two leg-receiving apertures and positioned atop a stepped tray support surface such that the primary tray structure is maintained in a horizontal orientation.
[0024] FIG. 12 is a first side plan view of a tray-supporting leg showing a vertical groove portion and a series of horizontal groove portions extending from the vertical groove portion.
[0025] FIG. 13 is a second side plan view of the tray-supporting leg showing the terminal ends of the horizontal groove portions otherwise shown in FIG. 12 .
[0026] FIG. 14 is a top perspective view of a tray-supporting leg a first tab-receiving channel in its entirety and an inlet of a second opposed tab-receiving channel.
[0027] FIG. 15 is a cross-sectional view of the tray assembly as taken along a plane extending through opposed tray-support legs as received in opposed leg-receiving apertures to show opposed aperture tabs received in opposed horizontal groove portions for fixing the legs relative to the primary tray structure.
[0028] FIG. 16 is a cross-sectional view of attached first and second tray assemblies as taken along a plane extending through tongue-and-groove type fastening means for showing how the first and second tray assemblies may couple to one another.
[0029] FIG. 17 is a bottom perspective view of the tray assembly showing a pair of legs received in leg-stowage slots.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0030] Referring now to the drawings, the preferred embodiment of the present invention concerns a tray assembly 10 for use in combination with variable level support surfacing so as to provide a horizontal tray structure for holding and/or compartmentalizing various matter thereupon. It is contemplated that the variable level support surfacing may be defined by a stepped surface such as a stair case 11 as generally depicted in FIG. 11 ; or an inclined surface such as a sloped roof 12 as generally depicted in FIG. 10 ; or a horizontal surface as may be generally gleaned from FIGS. 6-9 .
[0031] The tray assembly 10 comprises a tray structure 13 having an upper tray surface or portion as generally depicted in FIGS. 1-3 , 5 , 10 , and 11 ; and a lower tray surface or portion as generally depicted in FIGS. 4 and 17 . It should be noted that the primary tray structure 13 is upendable such that the upper and lower tray portions may be interchangeably used as matter-supporting surfaces.
[0032] In other words, depending on the task at hand, the user may wish to utilize the upper portion to support/organize matter as seen in the noted figures with a first pocket arrangement or alternatively the lower portion with a second pocket arrangement. Pockets 40 are further preferably formed in the upper and lower portions to provide the user with added means for organizing matter upon the tray structure 13 .
[0033] The upper and lower tray surface or portions further comprise opposed leg-receiving slots or grooves 14 , which extend toward the opposed tray surfaces or portions and are sufficiently deep to receive and stow tray supportive legs 15 as generally depicted in FIG. 5 , 10 , and 11 . FIGS. 1-3 depict legs removed from the slots or grooves 14 . When legs are removed from the slots or grooves 14 , other matter (e.g. hardware) may be received therein.
[0034] The slots or grooves may be outfitted with tabs 21 sized and shaped so as to selectively retain the legs 15 within the slots 14 . The upper tray surface or portion depicts the slots 14 relatively closer to the outer periphery of the tray structure 13 and the lower tray surface or portion depicts the slots relatively closer to the center of the tray structure 13 .
[0035] The upper and lower slots or grooves 14 are substantially parallel to one another and extend between end-located, opposed leg-receiving apertures 16 . In this last regard, it may be noted that the tray structure 13 may be rectangular in shape and the slots 14 may preferably extend intermediate opposed pairs of leg-receiving apertures 16 in the length direction of the tray structure 13 .
[0036] The opposed leg-receiving apertures 16 situated at or adjacent the four corners of the tray structure 13 extend through or from the upper to the lower tray surfaces. As introduced heretofore, at least one pair of tray support legs 15 form part of the tray assembly 10 , which legs 15 are removably receivable in the tray-receiving slots 14 for stowage, and are removably receivable in the leg-receiving apertures 16 for supporting the tray structure 13 in a horizontal and spaced orientation relative to a support surface.
[0037] Together, the leg-receiving apertures 16 and tray support legs 15 preferably comprise certain means for selectively and orthogonally varying the position of the respective tray support legs 15 relative to the respective leg-receiving apertures 16 , which means essentially function to enhance a user's ability to use the tray assembly in combination with variable level surfacing.
[0038] Said means for selectively and orthogonally varying the position of the respective tray support legs 15 relative to the respective leg-receiving apertures 16 may be preferably and cooperatively defined by aperture tabs 17 formed within the leg-receiving apertures 16 and tab-receiving channels 18 formed within the tray support legs 15 . The aperture tabs 17 are sized and shaped to be receivable in the tab-receiving channels 18 so as to allow the user to orthogonally adjust the position of the tray support legs 15 relative to the leg-receiving apertures 16 .
[0039] In this last regard, it should be noted that the tab-receiving channels 18 comprise a vertical groove portion (as at 19 ) and a series of horizontal groove portions (as at 20 ), which horizontal groove portions 20 are contiguous with the vertical groove portion 19 . The vertical groove portions 19 of each leg 15 thus enable the user to orthogonally adjust the position of the respective tray support legs 15 relative to the leg-receiving apertures 16 and the horizontal groove portions enable the user to orthogonally fix the position of the respective tray support legs 15 relative to the leg-receiving apertures 16 . In other words the tab 17 may be received in the vertical groove portion 19 so that the leg 15 may extend through the aperture 16 and be displaced orthogonally relative thereto. The leg 15 may then be rotated such that the tab 17 may be guided into a horizontal groove portion 20 so that the leg 15 may be orthogonally fixed relative to the aperture 16 .
[0040] To enhance the stability of the tray support legs 15 as removably received in the leg-receiving apertures 16 , it is contemplated that the leg-receiving apertures 16 may each preferably comprise opposed aperture tabs 17 , and the tray support legs 15 may each preferably comprise opposed sets of tab-receiving channels 18 . The opposed cooperative means for selectively and orthogonally varying the position of the respective tray support legs 15 relative to the respective leg-receiving apertures 16 provide bi-directional or opposed structure for further orthogonally fixing the legs 13 at a given displacement relative to the tray structure 13 .
[0041] The tray assembly preferably further comprises certain means for coupling a second tray structure 30 to the first tray structure 13 , which second tray structure 30 is substantially identical to the first tray structure 13 . It is contemplated that the means for coupling the second tray structure 30 to the first tray structure 3 may preferably be defined by tongue-and-groove type flanges 22 that extend outwardly from the side(s) of the tray structures 13 and 30 .
[0042] It may be seen from an inspection of the figures that flanges 22 are of two types, namely outwardly and upwardly extending flanges as at 23 , and outwardly and downwardly extending flanges as at 24 . The flanges 21 are arranged on the first and second tray structures 10 and 30 such that the flanges 24 mate with or couple with flanges 23 as generally depicted in FIG. 16 . It may be seen from a consideration of the figures, and in particular FIG.16 that the upwardly extending portions of flanges 23 are sized and shaped to be received in the grooves adjacent the downwardly extending portions of flanges 24 .
[0043] While the above description contains much specificity, this specificity should not be construed as limitations on the scope of the invention, but rather as an exemplification of the invention. For example, it is contemplated that the present invention essentially describes and teaches a tray assembly for use in combination with variable level support surfacing so as to provide or maintain a horizontal tray. The tray assembly comprises a first or primary tray structure and at least one pair of support legs. The first tray structure has an upper tray portion, a lower tray portion, and opposed leg-receiving apertures extending from the upper to lower tray portions. The tray support legs are removably and orthogonally receivable in the leg-receiving apertures for supporting the first tray structure in horizontal spaced relation relative to a support surface.
[0044] The leg-receiving apertures and tray support legs may preferably comprise certain means for selectively and orthogonally varying the position of the respective tray support legs relative to the respective leg-receiving apertures, which means may well further function to enhance a user's ability to use the tray in combination with variable level surfacing. Said means may be cooperatively defined by aperture tabs formed within the leg-receiving apertures and tab-receiving grooves or channels formed within the tray support legs. The aperture tabs are receivable in the tab-receiving grooves for adjusting the position of the tray support legs relative to the leg-receiving apertures.
[0045] The tab-receiving grooves may comprise a vertical groove portion and a series of horizontal groove portions continuous with the vertical groove portion. The vertical groove portion enables the user to orthogonally adjust the position of the respective tray support legs relative to the leg-receiving apertures, and the horizontal groove portions enable the user to orthogonally fix the position of the respective tray support legs relative to the leg-receiving apertures.
[0046] Each leg-receiving aperture may preferably comprise opposed aperture tabs, and each tray support leg may preferably comprise opposed set of tab-receiving grooves. The opposed aperture tabs and opposed sets of tab-receiving grooves may well enhance stability of the tray support legs as removably received in the leg-receiving apertures. It is contemplated that the legs 15 could comprise male structure (such as certain leg tabs), however, for receipt in female structure (such as certain aperture channels) otherwise formed in the apertures 16 , though this latter feature has not been specifically illustrated.
[0047] The tray assembly according to the present invention may further preferably comprise certain means for coupling a second tray structure to the first tray structure. As earlier stated, these means may be preferably defined by certain flange type tongue and groove structure, but could well be provided by certain other structure such as fastening hardware and alignable fastening hardware apertures on adjacent tray structures.
[0048] The first and second (or third) tray structures may each preferably comprises certain leg-stowage means for selectively stowing the tray support legs. In this regard, it is contemplated that either the upper tray portion and/or the lower tray portion may comprise leg-receiving slots or grooves (as at 14 ) outfitted with means for removably retaining the legs received therein, which grooves 14 are sized and shaped so as to be sufficiently deep to completely receive the legs within the thickness of the tray structure between the maximum upper and lower dimensions of the upper and lower tray portions.
[0049] Stated another way, the tray assembly according to the present invention may be said to provide a tray structure having upper and lower tray portions, and leg-receiving apertures (as at 16 ) axially and orthogonally extending from the upper to lower tray portions. A plurality of support legs, the support legs are coaxially receivable in the leg-receiving apertures for supporting the tray structure in horizontal spaced relation relative to a support surface.
[0050] The leg-receiving apertures and support legs may well comprise certain means for selectively and orthogonally varying the position of the respective support legs relative to the respective leg-receiving apertures, which means may be said to further enhance a user's ability to orient the tray in horizontal spaced relation relative to a support surface. The means may be cooperatively defined by tabs and grooves or channels respectively formed in either the legs or apertures. The tabs then are receivable in the grooves for adjusting the position of the support legs relative to the leg-receiving apertures.
[0051] Accordingly, although the invention has been described by reference to a preferred embodiment, it is not intended that the novel tray assembly be limited thereby, but that modifications thereof are intended to be included as falling within the broad scope and spirit of the foregoing disclosure and the appended drawings. | A tray assembly may be used in combination with inclined, stepped, level or variable level support surfacing. The tray assembly may be used in tandem with identical embodiments of the tray assembly for forming larger, linked tray assemblages. The tray assembly may comprise a plurality of legs, which are stowable in a primary tray structure when not being used to elevate the tray structure above a support surface. When used to elevate the primary tray structure above variable level support surfacing, the legs may each be adjusted relative to the primary tray structure for properly maintaining a horizontal tray configuration relative to the support surfacing. The tray support legs are removably receivable in the tray-receiving slots for stowage, and are removably receivable in leg-receiving apertures for supporting the primary tray structure in horizontal spaced relation relative to a support surface. | 4 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. Ser. No. 11/177,498 filed on Jul. 8, 2005, now abandoned which is a continuation of PCT International Patent Application No. PCT/EP04/000149, filed on Jan. 9, 2004, designating the United States of America, and published, in English, as PCT International Publication No. WO 2004/063386 A2 on Jul. 29, 2004, which application claims priority to European Patent Application Serial No. 03075091.3 filed on Jan. 10, 2003, the contents of the entirety of each are incorporated herein by this reference.
TECHNICAL FIELD
The invention relates to biotechnology generally and, more particularly, to methods of selecting animals, such as mammals, in particular, domestic animals, such as breeding animals or animals destined for slaughter, for having desired genotypic or potential phenotypic properties, in particular, related to muscle mass and/or fat deposition or, in the case of mammals, to teat number.
BACKGROUND
Herein, a domestic animal is defined as an animal being purposely selected, or having been derived from an animal having been purposely selected, for having desired genotypic or potential phenotypic properties.
Domestic animals provide a rich resource of genetic and phenotypic variation; traditionally, domestication involves selecting an animal or its offspring for having desired genotypic or potential phenotypic properties. This selection process has in the past century been facilitated by growing understanding and utilization of the laws of Mendelian inheritance. One of the major problems in breeding programs of domestic animals is the negative genetic correlation between reproductive capacity and production traits. This is, for example, the case in cattle (a high milk production generally results in slim cows and bulls), poultry (broiler lines have a low level of egg production and layers have generally very low muscle growth), pigs (very prolific sows are, in general, fat and have comparatively less meat), or sheep (high prolific breeds have low carcass quality and vice versa). PCT International Patent Application WO 00/36143 provides a method for selecting an animal for having desired genotypic or potential phenotypic properties comprising testing the animal for the presence of a parentally imprinted qualitative or quantitative trait locus (QTL). Knowledge of the parental imprinting character of various traits allows selection of, for example, sire lines homozygous for a paternally imprinted QTL, for example, linked with muscle production or growth; the selection for such traits can thus be less stringent in dam lines in favor of the reproductive quality.
The phenomenon of genetic or parental imprinting has earlier never been utilized in selecting domestic animals; it was never considered feasible to employ this elusive genetic characteristic in practical breeding programs. A breeding program, wherein knowledge of the parental imprinting character of a desired trait, as demonstrated herein is utilized, increases the accuracy of the breeding value estimation and speeds up selection compared to conventional breeding programs. For example, selecting genes characterized by paternal imprinting is provided to help increase uniformity; a (terminal) parent homozygous for the “good or wanted” alleles will pass them to all offspring, regardless of the other parent's alleles, and the offspring will all express the desired parent's alleles. This results in more uniform offspring. Alleles that are interesting or favorable from the maternal side are often the ones that have opposite effects to alleles from the paternal side. For example, in meat animals such as pigs, alleles linked with meat or carcass quality traits such as intramuscular fat or muscle mass could be fixed in the dam lines while alleles linked with reduced back fat could be fixed in the sire lines. Other desirable combinations are, for example, fertility, teat number and/or milk yield in the female line with increased growth rates, reduced back fat and/or increased muscle mass in the male lines.
The purpose of breeding programs in livestock is to enhance the performances of animals by improving their genetic composition. In essence, this improvement accrues by increasing the frequency of the most favorable alleles for the genes influencing the performance characteristics of interest. These genes are referred to as QTL. Until the beginning of the nineties, genetic improvement was achieved via the use of biometrical methods, but without molecular knowledge of the underlying QTL. Now, the identification of causative mutations for Quantitative Trait Loci (QTLs) is a major hurdle in genetic studies of multifactorial traits and disorders. The imprinted IGF2-linked QTL is one of the major porcine QTLs for body composition. It was first identified in intercrosses between the European Wild Boar and Large White domestic pigs and between Piétrain and Large White pigs. (1, 2) The data showed that alleles from the Large White and Piétrain breed, respectively, were associated with increased muscle mass and reduced back-fat thickness, consistent with the existing breed differences in the two crosses. A paternally expressed IGF2-linked QTL was subsequently documented in intercrosses between Chinese Meishan and Large White/Landrace pigs (3) and between Berkshire and Large White pigs. (4) In both cases, the allele for high muscle mass was inherited from the lean Large White/Landrace breed. However, there are a large number of potentially important elements that may influence IGF2 function. Recent sequence analysis (Amarger et al. 2002) provided a partial sequence of the INS-IGF2-H19 region and revealed as many as 97 conserved elements between human and pig.
DISCLOSURE OF THE INVENTION
The invention provides a method for selecting an animal for having desired genotypic or potential phenotypic properties comprising testing the animal for the presence of a qualitative or quantitative trait locus (QTL). Here, we show that a paternally expressed QTL affecting muscle mass, fat deposition and teat number is caused by a single nucleotide substitution in intron 3 of IGF2. The mutation occurs in an evolutionary conserved CpG island that is hypomethylated in skeletal muscle. The function of the conserved CpG island was not known before. IGF2-intron3-nt3072 is part of the evolutionary conserved CpG island with a regulatory function, located between Differentially Methylated Region 1 (DMR1) and a matrix attachment region previously defined in mice. (11-13) The 94 bp sequence around the mutation shows about 85% sequence identity to both human and mouse, and the wild-type nucleotide at IGF2-intron3-nt3072 is conserved among the three species ( FIG. 4A ).
A qualitative trait nucleotide (QTN) occurs three bp downstream of an eight bp palindrome also conserved between the three species. The methylation status of the 300 bp fragment centered on IGF2-intron3-nt3072 and containing 50 CpG dinucleotides was examined by bisulphite sequencing in four-month-old Q pat /q mat and q pat /Q mat animals. In skeletal muscle, paternal and maternal chromosomes were shown to be essentially unmethylated (including the IGF2-intron3-nt3071 C residue) irrespective of the QTL genotype of the individual (3.4% of CpGs methylated on average; FIG. 5A ). The CpG island was more heavily and also differentially methylated in liver, 33% of the CpGs were methylated on the maternal alleles versus 19% on the paternal allele. Unexpectedly, therefore, this CpG island behaves as a previously unidentified DMR in liver, the repressed maternal allele being more heavily methylated than the paternal allele, which is the opposite of what is documented for the adjacent DMR1 in the mouse.
To further uncover a function for this element, we performed electrophoretic mobility shift analyses (EMSA) using 27 bp oligonucleotides spanning the QTN and corresponding to the wild-type (q) and mutant (Q) sequences. Nuclear extracts from murine C2C12 myoblast cells, human HEK293 cells, and human HepG2 cells were incubated with radioactively labeled q or Q oligonucleotides. One specific band shift (complex C1 in FIG. 5B ) was obtained with the wild-type (q) but not the mutant (Q) probe using extracts from C2C12 myoblasts; similar results were obtained using both methylated and unmethylated probes. A band shift with approximately the same migration, but weaker, was also detected in extracts from HEK293 and HepG2 cells. The specificity of the complex was confirmed since competition was obtained with ten-fold molar excess of unlabeled q probe, whereas a 50-fold excess of unlabeled Q probe did not achieve competition ( FIG. 5B ). Thus, the wild-type sequence binds a nuclear factor, and this interaction is abrogated by the mutation. This also means that there could be other mutations in this region that are important in pigs or other species.
Furthermore, our data show that the CpG island contains both Enhancer and Silencer functions so that there may be several nuclear factors binding to this CpG island except for the one already shown here. Our results provide a method for isolating such nuclear factors. We provide a stretch of oligonucleotides that can be used to fish out such proteins. Pigs carrying the mutation have a three-fold increase in IGF2 mRNA expression in postnatal muscle. The mutation abrogates in vitro interaction with a nuclear factor, most likely a repressor. The mutation has experienced a selective sweep in several pig breeds.
As further described in the Detailed Description herein, we have used a haplotype-sharing approach to refine the map position of the QTL. (5) We assumed that a new allele (Q) promoting muscle development occurred g generations ago on a chromosome carrying the wild-type allele (q). We also assumed that the favorable allele has gone through a selective sweep due to the strong selection for lean growth in commercial pig populations. Twenty-eight chromosomes with known QTL status were identified by marker-assisted segregation analysis using cross-bred Piétrain and Large White boars. All 19 Q-bearing chromosomes shared a haplotype in the 90 kilobase pairs (kb) interval between the microsatellites PULGE1 and SW2C9 (IGF2 3′-UTR), which was not present among the q chromosomes and was, therefore, predicted to contain the QTL. In contrast, the nine q chromosomes exhibited six distinct marker haplotypes in the same interval. This region is part of the CDKN1C-HR19 imprinted domain and contains INS and IGF2 as the only known paternally expressed genes. With this insight, the invention provides a method for selecting an animal for having desired genotypic or potential phenotypic properties comprising testing the animal, a parent of the animal or its progeny for the presence of a nucleic acid modification affecting the activity of an evolutionary conserved CpG island, located in intron 3 of an IGF2 gene and/or affecting binding of a nuclear factor to an IGF2 gene.
In a preferred embodiment, the invention provides a method for selecting an animal for having desired genotypic or potential phenotypic properties comprising testing a nucleic acid sample from the animal for the presence of the single nucleotide substitution. A nucleic acid sample can be obtained, in general, from various parts of the animal's body by methods known in the art. Traditional samples for the purpose of nucleic acid testing are blood samples or skin or mucosal surface samples, but samples from other tissues can be used as well, in particular, sperm samples, oocyte or embryo samples can also be used. In such a sample, the presence and/or sequence of a specific nucleic acid, be it DNA or RNA, can be determined with methods known in the art, such as hybridization or nucleic acid amplification or sequencing techniques known in the art. The invention also provides testing such a sample for the presence of nucleic acid wherein the QTN or allele associated therewith is associated with the phenomenon of parental imprinting, for example, where it is determined whether a paternal or maternal allele comprising the QTN is capable of being predominantly expressed in the animal.
In a preferred embodiment, the invention provides a method wherein the nuclear factor is capable of binding to a stretch of nucleotides, which in the wild-type pig, mouse or human IGF2 gene, is part of an evolutionary conserved CpG island, located in intron 3 of the IGF2 gene. Binding should preferably be located at a stretch of nucleotides spanning a QTN (qualitative trait nucleotide), which comprises a nucleotide (preferably a G to A) transition, which in the pig is located at IGF2-intron3-nt3072. It is preferred that the stretch is functionally equivalent to the sequence as shown in FIG. 4 , which comprises the sequence 5′-GATCCTTCGCCTAGGCTC(A/G)CAGCGCGGGAGCGA-3′ (SEQ ID NO: 1) identifying the overlap with the QTN, wherein functional equivalence preferably entails that the stretch is spanning the QTN, and preferably overlaps with at least two or three nucleotides at or on both sides of the QTN, although the overlaps may be longer. Also, functional equivalence entails a sequence homology of at least 50%, preferably at least 60%, more preferably at least 70%, even more preferably at least 80%, most preferred at least 90%, of the stretch overlapping the QTN. The stretch is preferably from at least five to at about 94 nucleotides long, more preferably from about ten to 50, most preferably from about 15 to 35 nucleotides, and it is preferred that it comprises a palindromic octamer sequence as identified in FIG. 4 . In a preferred embodiment, the invention provides a method wherein the nucleic acid modification comprises a nucleotide substitution, wherein the pig the substitution comprises a G to A transition at IGF2-intron3-nt3072. Abrogating or reducing binding of the nuclear factor to the IGF2 gene allows for modulating IGF2 mRNA transcription in a cell provided (naturally or by recombinant means) with the gene.
To further characterize the functional significance of the IGF2 Q mutation, we studied its effect on transcription by employing a transient transfection assay in mouse C2C12 myoblasts. We made Q and q constructs containing a 578 bp fragment from the actual region inserted in front of a Luciferase reporter gene driven by the herpes thymidine kinase (TK) minimal promoter. The two constructs differed only by the IGF2-intron3-nt3072G→A transition. The ability of the IGF2 fragments to activate transcription from the heterologous promoter was compared with the activity of the TK-promoter alone. The presence of the q-construct caused a two-fold increase of transcription, whereas the Q-construct caused a significantly higher, seven-fold, increase ( FIG. 5C ). Our interpretation of this result, in light of the results from the EMSA experiment, is that the Q mutation abrogates the interaction with a repressor protein that modulates the activity of a putative IGF2 enhancer present in this CpG island. This view is consistent with our in silico identification of potential binding sites for both activators and repressors in this intronic DNA fragment. (14)
The in vivo effect of the mutation on IGF2 expression was studied in a purpose-built Q/q×Q/q intercross counting 73 offspring. As a deletion encompassing DMR0, DMR1, and the associated CpG island derepresses the maternal IGF2 allele in mesodermal tissues in the mouse, (12) we tested the effect of the intron3-nt3072 mutation on IGF2 imprinting in the pig. This was achieved by monitoring transcription from the paternal and maternal IGF2 alleles in tissues of q/q, Q pat /q mat , and q pat /Q mat animals that were heterozygous for the SWC9 microsatellite located in the IGF2 3′UTR. Imprinting could not be studied in Q/Q animals which were all homozygous for SWC9. Before birth, IGF2 was shown to be expressed exclusively from the paternal allele in skeletal muscle and kidney, irrespective of the QTL genotype of the fetuses. At four months of age, weak expression from the maternal allele was observed in skeletal muscle, however, at comparable rates for all three QTL genotypes ( FIG. 6 , Panel A). Only the paternal allele could be detected in four month old kidney (data not shown). Consequently, the mutation does not seem to affect the imprinting status of IGF2. The partial derepression of the maternal allele in skeletal muscle of all QTL genotypes may, however, explain why in a previous study muscular development was found to be slightly superior in q pat /Q mat versus q/q animals, and in Q/Q versus Q pat /q mat animals. (2)
The Q allele was expected to be associated with an increased IGF2 expression since IGF2 stimulates myogenesis. (6) To test this, we monitored the relative mRNA expression of IGF2 at different ages in the Q/q×Q/q intercross using both Northern blot analysis and real-time PCR ( FIG. 6 , Panels B and C). The expression levels in fetal muscle and postnatal liver was about ten-fold higher than in postnatal muscle. No significant difference was observed in fetal samples or in postnatal liver samples, but a significant three-fold increase of postnatal IGF2 mRNA expression in skeletal muscle was observed in (Q/Q or Q pat /q mat ) versus (q pat /Q mat or q/q) progeny. Herewith, the invention provides a method for modulating mRNA transcription of an IGF2 gene in a cell or organism provided with the gene comprising modulating binding of a nuclear factor to an IGF2 gene, in particular, wherein the nuclear factor is capable of binding to a stretch of nucleotides (as identified above), which in the wild-type pig, mouse or human IGF2 gene, is part of an evolutionary conserved CpG island, located in intron 3 of the IGF2 gene. The significant difference in IGF2 expression revealed by real-time PCR was confirmed using two different internal controls, GAPDH ( FIG. 6 , Panel C) and HPRT. (15) We found an increase of all detected transcripts originating from the three promoters (P2-P4) located downstream of the mutated site. Combined, these results provide strong evidence for IGF2 being the causative gene. The lack of significant differences in IGF2 mRNA expression in fetal muscle and postnatal liver are consistent with our previous QTL study showing no effect of the IGF2 locus on birth weight and weight of liver. (2)
Accordingly, a method according to the invention is herein provided allowing testing for and modulation of desired genotypic or potential phenotypic properties comprising muscle mass, fat deposition or teat numbers (of mammals). Such testing is applicable in man and animals alike (animals herein defined as including humans). In humans, it is, for example, worthwhile to test for the presence of a nucleic acid modification affecting the activity of an evolutionary conserved CpG island, located in intron 3 of an IGF2 gene or affecting binding of a nuclear factor to an IGF2 gene, as provided herein, to test, for example, the propensity or genetic predisposition or likelihood of muscle growth or muscularity in humans versus propensity or genetic predisposition or the likelihood of obesity. In domestic animals, such testing may be undertaken to select the best or most suitable animals for breeding, or to preselect domestic animals destined for slaughter. An additional trait to be selected for concerns teat number, a quality highly valued in sow lines to allow for suckling large litters. A desirable breeding combination as provided herein comprises, for example, increased teat number in the female line with increased growth rates, and reduced back fat and/or increased muscle mass in the male lines. It is herein also shown that the mutation influences teat number. The Q allele that is favorable with respect to muscle mass and reduced back fat is the unfavorable allele for teat number. This strengthens the possibility of using the paternal imprinting character of this QTL in breeding programs. Selecting maternal lines for the q allele will enhance teat number, a characteristic that is favorable for the maternal side. On the other hand, paternal lines can be selected for the Q allele that will increase muscle mass and reduce back fat, characteristics that are of more importance in the paternal lines. Terminal sires that are homozygous QQ will pass the full effect of increased muscle mass and reduced back fat to the slaughter pigs, while selection of parental sows that express the q allele will allow for the selection of sows that have more teats and suckle more piglets without affecting slaughter quality.
As indicated above, the insulin-like growth factor 2 (IGF2) gene was mapped to the distal tip of the short arm on chromosome 2 in swine. Gene mapping studies indicated that this paternally expressed QTL at the IGF2 gene region has a large effect on back fat thickness and carcass leanness (e.g., Jeon et al. (1999), Nature Genetics 21, 157-158; Nezer et al. (1999), Nature Genetics 21, 155-156). Recently, a mutation in the regulatory region of the IGF2 gene has been identified to be the cause underlying the QTL effect on muscle growth and fat deposition (Van Laere et al. (2003), Nature 425:832-836). This single nucleotide substitution (G-A), located at position 3072 in the intron 3 of IGF2 gene, increases gene expression of IGF2 in muscle three-fold, stimulates muscle growth at the expense of back fat and results in leaner swine carcass and lower back fat.
The large effect of the QTL on lean meat and back fat without influence on growth or meat quality, makes this an attractive QTL to use in the breeding program. Terminal sires have been selected to be homozygous for the lean allele (AA) in order to pass the full effect to their offspring. Field results have been reported by several authors (Scheller et al. (2002), Proceedings of the 27 th Annual National Swine Improvement Federation, Des Moines, Iowa, USA ; N. Buys (2003), Proceedings of the 28 th Annual National Swine Improvement Federation, Des Moines, Iowa, USA , pp 146-149).
It is generally believed that prolificacy and sow longevity is reduced as a result of the genetic selection for increased leanness and lowering fat deposition (see, e.g., P. Mathur and Y. Liu (2003), Proceedings of the 28 th Annual National Swine Improvement Federation, Des Moines, Iowa, USA , pp 155-163). Body fat deposition is necessary to sustain sow reproduction performance, for example, to support adequate milk production and to limit body weight loss. The selection for leaner carcasses, demanded by the packing industry and consumers, may conflict with the prolificacy and longevity of the sow and lead to increased replacement costs of sows in pig production. The QTN (quantitative trait nucleotide) in the IGF2 gene might provide a possibility to overcome this conflict. The imprinting character of the gene might be used to produce lean slaughter pigs from fatter dams that inherited the wild-type allele from their father (genotype of Grand parent boar=GG), crossed with terminal sires being homozygous for the lean allele (AA). The objective of this experiment was to investigate a possible effect of the QTN at the IGF2 gene on prolificacy and longevity.
The details of the experiment are described in Example 5. It was found that sows that inherited the wild-type allele from their father had significantly more piglets born alive, total born and weaned, while there was no effect on stillborn piglets (see, Example 5, Table 4). No effect on any of these prolificacy data could be observed when data were analyzed according to the allele inherited from the mother (maternal allele). Also, if sows from heterozygous dams were taken into account and grouped according to the maternal allele, again no significant effect on prolificacy could be observed, which was expected since the maternal allele is not expressed.
The parity or average number of cycles per sow was also found to be higher in sows that inherited G from their father as compared to those that received the A allele, which points to a beneficial effect on longevity. This is related to higher litter size since that is a major criterion for elimination in the selection program.
Thus, the IGF2-intron3 G3072A mutation (herein also referred to as “IGF2+” or “A”-allele; the wild-type being the igf2- or G-allele) has an influence on prolificacy and longevity in sows, which allows for the possibility of using the same imprinted QTN for different selection in sire and dam lines. Terminal sires should be homozygous for the lean allele to give uniform and lean slaughter pigs, while dam lines can benefit from a selection for the wild-type allele since this has a beneficial effect on prolificacy and longevity. Because of the imprinted character of the gene, selection for the fatter allele in sow lines will not influence the carcass quality of the offspring.
Thus, the invention provides a method for selecting a domestic animal for having desired genotypic properties comprising testing the animal for the presence of a parentally imprinted quantitative trait locus (QTL) or a mutation therein and to the use of an isolated and/or recombinant nucleic acid comprising a parentally imprinted quantitative trait locus (QTL) or a mutation therein or functional fragment derived thereof to select a breeding animal or animal destined for slaughter for having desired genotypic or potential phenotypic properties. The test may, for instance, comprise testing a sample from the pig for the presence of a quantitative trait locus (QTL) located at a Sus scrofa chromosome 2 mapping at position 2 p1.7., wherein the QTL is paternally expressed, i.e., is expressed from the paternal allele.
In particular, the genotypic or potential phenotypic properties are selected from the group consisting of muscle mass, fat deposition, lean meat, lean back fat, sow prolificacy and sow longevity. In particular, improved sow prolificacy may include such phenotypic expressions as higher teat number, more piglets born alive, higher litter size, higher number of total born and weaned piglets with no effect on stillborn piglets. Improved sow longevity may, in particular, include such phenotypic expressions as parity or average number of cycles per sow.
Thus, the above-described IGF2 mutation influencing lean meat also influences a number of other positive traits and allows for marker-assisted selection in opposite directions in sire and dam lines due to the parentally imprinting character of the mutation. The mutation increases muscle mass at the expense of back fat with, on average, 2% to 4% more lean meat. This effect on leanness is of the same magnitude as reported for the Halothane gene but without any of the well-known deleterious effects on meat quality and animal health. Homozygous-positive terminal sires (IGF2+/IGF2+) will pass the full effect to the slaughter pigs, regardless of the genotype of the mother. Furthermore, such selection principles allow for the possibility to push a far higher proportion of lower grading pigs into the higher payment categories. The experiment described in Example 4 shows that parent sows benefit from inheriting the negative gene (igf2−) from their father: they are more prolific and have an increased longevity. Parent sows are fatter but this will have no effect on the carcass quality of the slaughter pig (see, FIG. 7 ).
The invention also provides a method for identifying a compound capable of modulating mRNA transcription of an IGF2 gene in a cell or organism provided with the gene comprising providing a first cell or organism having a nucleic acid modification affecting the activity of an evolutionary conserved CpG island, located in intron 3 of an IGF2 gene and/or affecting binding of a nuclear factor to an IGF2 gene and a second cell or organism not having the modification further comprising providing the first or the second cell or organism with a test compound and determining IGF2 mRNA transcription in the first and second cell or organism and selecting a compound capable of modulating IGF2 mRNA transcription. An example of such a compound as identifiable herewith comprises a stretch of oligonucleotides spanning a QTN (qualitative trait nucleotide), which comprises a nucleotide (preferably a G to A) transition, which in the pig is located at IGF2-intron3-nt3072. It is preferred that the stretch is functionally equivalent to the sequence as shown in FIG. 4 , which comprises the sequence 5′-GATCCTTCGCCTAGGCTC(A/G)CAGCGCGGGAGCGA-3′ (SEQ ID NO: 1) identifying the overlap with the QTN, wherein functional equivalence preferably entails that the stretch is spanning the QTN, and preferably overlaps with at least two or three nucleotides at or on both sides of the QTN, although the overlaps may be longer. Also, functional equivalence entails a sequence homology of at least 50%, preferably at least 60%, more preferably at least 70%, even more preferably at least 80%, most preferred at least 90% of the stretch overlapping the QTN. The stretch is preferably from at least five to about 94 nucleotides long, more preferably from about ten to 50, most preferably from about 15 to 35 nucleotides, and it is preferred that it comprises a palindromic octamer sequence as identified in FIG. 4 .
An alternative compound as provided herein comprises a functional analogue of the stretch, the alternative compound or oligonucleotide analogue functionally at least capable of modulating the activity of an evolutionary conserved CpG island, located in intron 3 of an IGF2 gene and/or modulating binding of a nuclear factor to an IGF2 gene, preferably effecting the modulation at the site of the QTN. In electrophoretic mobility shift analyses (EMSA), such compounds, e.g., in FIG. 2 identified as nuclear factor, or compounds competing with the binding of the factor to the IGF2 gene, can be further identified and selected. A typical example of such an EMSA is given in the detailed description. It is preferred that the nuclear factor is capable of binding to a stretch of nucleotides, which in the wild-type pig, mouse or human IGF2 gene, is part of an evolutionary conserved CpG island, located in intron 3 of the IGF2 gene. Oligonucleotide compounds or probes spanning the QTN are herein provided that have the desired effect. Such compounds or probes are preferably functionally equivalent to the sequence 5′-GATCCTTCGCCTAGGCTC(A/G)CAGCGCGGGAGCGA-3′ (SEQ ID NO: 1).
The invention also provides a method for identifying a compound capable of affecting the activity of an evolutionary conserved CpG island, located in intron 3 of an IGF2 gene and/or modulating binding of a nuclear factor to an IGF2 gene comprising providing a stretch of nucleotides, which in the wild-type pig, mouse or human IGF2 gene, is part of an evolutionary conserved CpG island, located in intron 3 of the IGF2 gene. Such testing may be done with single oligonucleotides or analogues thereof, or with a multitude of such oligonucleotides or analogues in an array fashion, and may further comprise providing a mixture of DNA-binding proteins derived from a nuclear extract of a cell and testing these with the array or analogue or oligonucleotide under study. Testing may be done as well with test compounds provided either singularly or in an array fashion and optionally further comprises providing a test compound and determining competition of binding of the mixture of DNA-binding proteins to the stretch of nucleotides in the presence or absence of the test compound(s). To find active compounds for further study or, eventually, for pharmaceutical use, it suffices to select a compound capable of inhibiting binding of the mixture to the stretch, wherein the stretch is functionally equivalent to the sequence 5′-GATCCTTCGCCTAGGCTC(A/G)CAGCGCGGGAGCGA-3′ (SEQ ID NO: 1).
The invention thus provides a compound identifiable with a method as described herein. Such a compound is, for example, derived from a stretch of oligonucleotides spanning a QTN (qualitative trait nucleotide), which comprises a nucleotide (preferably a G to A) transition, which in the pig is located at IGF2-intron3-nt3072. It is preferred that the stretch is functionally equivalent to the sequence as shown in FIG. 4 , which comprises the sequence 5′-GATCCTTCGCCTAGGCTC(A/G)CAGCGCGGGAGCGA-3′ (SEQ ID NO:1) identifying the overlap with the QTN, wherein functional equivalence preferably entails that the stretch is spanning the QTN, and preferably overlaps with at least two or three nucleotides at or on both sides of the QTN, although the overlaps may be longer. Also, functional equivalence entails a sequence homology of at least 50%, preferably at least 60%, more preferably at least 70%, even more preferably at least 80%, most preferred at least 90% of the stretch overlapping the QTN. The oligonucleotide compound is preferably from at least five to about 94 nucleotides long, more preferably from about ten to 50, most preferably from about ten to 35 nucleotides, and it is preferred that it comprises a palindromic octamer sequence as identified in FIG. 4 .
An alternative compound or functional analogue as provided herein comprises a functional analogue of the oligonucleotide compound, the alternative compound or oligonucleotide analogue functionally at least capable of modulating the activity of an evolutionary conserved CpG island, located in intron 3 of an IGF2 gene and/or modulating binding of a nuclear factor to an IGF2 gene, preferably effecting the modulation at the site of the QTN. For example, in electrophoretic mobility shift analyses (EMSA), such compounds, e.g., in FIG. 2 identified as nuclear factor, or compounds competing with the binding of the factor to the IGF2 gene, can be further identified and selected. A typical example of such an EMSA is given in the detailed description. The invention also provides a pharmaceutical composition comprising a compound as provided herein, and use of such a compound for the production of a pharmaceutical composition for the treatment of obesity, or for the treatment of muscle deficiencies. Furthermore, the invention provides a method for modulating mRNA transcription of an IGF2 gene in a cell or organism provided with the gene comprising treating or providing the cell or organism with a compound as provided herein.
There has been a strong selection for lean growth (high muscle mass and low fat content) in commercial pig populations in Europe and North America during the last 50 years. Therefore, we investigated how this selection pressure has affected the allele frequency distribution of the IGF2 QTL. The causative mutation was absent in a small sample of European and Asian Wild Boars and in several breeds that have not been strongly selected for lean growth (Table 1). In contrast, the causative mutation was found at high frequencies in breeds that have been subjected to strong selection for lean growth. The only exceptions were the experimental Large White population at the Roslin Institute that was founded from commercial breeding stocks in the UK around 1980, (16) as well as the experimental Large White populations used for the Piétrain/Large White intercross; (1) these two populations thus reflect the status in some commercial populations about 20 years ago and it is possible that the IGF2*Q allele is even more predominant in contemporary populations. The results demonstrate that IGF2*Q has experienced a selective sweep in several major commercial pig populations and it has apparently been spread between breeds by cross-breeding.
The results have important practical implications. The IGF2*Q mutation increases the amount of meat produced, at the expense of fat, by 3 to 4 kg for an animal slaughtered at the usual weight of about 100 kg. The high frequency of IGF2*Q among major pig breeds implies that this mutation affects the productivity of many millions of pigs in the Western world. The development of a simple diagnostic DNA test now facilitates the introgression of this mutation to additional breeds. This could be an attractive way to improve productivity in local breeds as a measure to maintain biological diversity. The diagnostic test will also make it possible to investigate if the IGF2*Q mutation is associated with any unfavorable effects on meat quality or any other trait. We and others have previously demonstrated that European and Asian pigs were domesticated from different subspecies of the Wild Boar, and that Asian germplasm has been introgressed into European pig breeds. (17) The IGF2*Q mutation apparently occurred on an Asian chromosome as it showed a very close relationship to the haplotype carried by Chinese Meishan pigs. This explains the large genetic distance that we observed between Q- and q-haplotypes ( FIG. 4 ). However, it is an open question whether the Q mutation occurred before or after the Asian chromosome was introduced into European pigs.
This study provides new insights in IGF2 biology. The role of IGF2 on prenatal development is well documented. (18, 19) Our observation that the Q mutation does not up-regulate IGF2 expression in fetal tissue until after birth, which demonstrates that IGF2 has an important role for regulating postnatal myogenesis. The finding that the sequence around the mutation does not match any known DNA-binding site shows that this sequence binds an earlier unknown nuclear factor. (14) Our results also imply that pharmacological intervention of the interaction between this DNA segment and the corresponding nuclear factor opens up new strategies for promoting muscle growth in humans, such as patients with muscle deficiencies, or for stimulating muscle development at the cost of adipose tissue in obese patients.
Applications of these insights are manifold. Applications in animals typically include diagnostic tests of the specific causative mutation in the pig and diagnostic tests of these and possible other mutations in this CpG island in humans, pigs or other meat producing animals.
It is now also possible to provide for transgenic animals with modified constitution of this CpG island or with modified expression of nuclear factors interacting with this sequence, and the invention provides the use of pharmaceutical compounds (including oligonucleotides) or vaccination to modulate IGF2 expression by interfering with the interaction between nuclear factors and the CpG island provided herein. Thus, instead of selecting animals, one may treat the animals with a drug, if not for producing meat then at least in experimental animals for studying the therapeutic effects of the compounds.
In humans, diagnostic tests of mutations predisposing to diabetes, obesity or muscle deficiency are particularly provided and pharmaceutical intervention to treat diabetes, obesity or muscle deficiency by modulating IGF2 expression based on interfering with the interaction between nuclear factors and the CpG island as provided herein is typically achievable with compounds, such as the above-identified nucleotide stretches or functional analogues thereof as provided herein.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 : QTL genotyping by marker-assisted segregation analysis. The graphs show, for 14 paternal half-sib pedigrees (P1, P2, . . . P14), the phenotypic mean±2 standard errors of the offspring sorted in two groups according to the homologue inherited from the sire. The number of offspring in each group is given above and below the error bars, respectively. The upper graph corresponds to the boars that were shown to be heterozygous “Qq” for the QTL, the lower graph to the boars that were shown to be homozygous at the QTL. Pedigrees for which the % lean meat was measured as “% lean cuts” (Nezer et al. 2002) are marked by L(eft axis), those for which “Piglog” was used (see, M&M) are marked by R(ight axis). The graph reports a Z-score for each pedigree, i.e., the log 10 of the H 1 /H 0 likelihood ratio where H 1 assumes that the boar is heterozygous “Qq” for the QTL, while H 0 assumes that the boar is homozygous “QQ” or “qq.” “Q” alleles associated with a positive allele substitution effect on % lean meat are marked by a diamond, “q” alleles by a circle. The number within the symbols differentiate the “Q” and “q” alleles according to the associated marker haplotype (see results of Example 1 and FIG. 2 ).
FIG. 2 : A. Schematic representation of the human 11p15 imprinted domain according to Onyango et al. (2000). B. BAC contig spanning the porcine orthologue of the 11p15 imprinted domain, assembled by STS content mapping. The length of the horizontal bars does not reflect the actual physical size of the corresponding BACs. C. Marker haplotypes of the five “Q” chromosomes (diamonds) and six “q” chromosomes (circles). Closely linked SNPs (<5 kb) were merged into poly-allelic multisite haplotypes (cfr. Table 2). The chromosome segments highlighted in green correspond to the haplotype shared by all “Q” chromosomes and therefore assumed to contain the QTL. The chromosome segment highlighted in red corresponds to a haplotype shared by chromosome “q 4 ” and chromosomes “Q 1-4 ,” which, therefore, excludes the QTL out of this region. The resulting most likely position of the QTL is indicated by the arrow.
FIG. 3 : Average probability for two chromosomes to be identical-by-descent at a given map position conditional on flanking marker data (p(IBD|MG)), along the chromosome segment encompassing the p57-H19 imprinted domain, computed according to Meuwissen and Goddard (2001). The positions of the markers defined according to Tables 1 and 2 are shown by the vertical dotted lines.
FIG. 4A : DNA sequence polymorphisms identified in a 28.6 kb segment spanning the porcine TH (exon 14), INS and IGF2 genes. The average (C+G) content of a moving 100-bp window is shown on a gray scale (black 100%, white 0%). The positions of evolutionary conserved regions, (7) including the DMR1 and associated CpG island in IGF2 intron 3, are marked by horizontal cylinders. The Viewgene program (25) was used to highlight the 258 differences between the reference Q P208 sequence, four Q, and ten q chromosomes. The position of the causative intron3-nt3072G→A mutation is marked by an asterisk. The sequence context of the conserved footprint surrounding intron3-nt3072 is shown for pig (pig-q (SEQ ID NO: 115) and pig-Q (SEQ ID NO: 116)), human (SEQ ID NO: 117), and mouse (SEQ ID NO: 118). The conserved palindromic octamer sequence is underlined. P=Piétrain; LW=Large White; LR=Landrace; H=Hampshire; M=Meishan; EWB=European Wild Boar; JWB=Japanese Wild Boar.
FIG. 4B : Neighbor-Joining tree of 18,560 bp of the porcine IGF2 gene based on 15 sequences classified as representing q and Q alleles. The analysis was restricted to the region from IGF2 intron 1 to SWC9 in the 3′UTR to avoid problems with the presence of recombinant haplotypes. The tree was constructed using MEGA version 2.1 (26) and positions with insertions/deletions were excluded. Bootstrap values (after 1000 replicates) are reported on the nodes.
FIG. 5A : Percentage methylation determined by bisulphite sequencing for the 300 bp fragment centered on intron3-nt3072, containing 50 CpG dinucleotides, in liver and skeletal muscle of four-month-old Q pat /q mat and q pat /Q mat individuals. The number of analyzed chromosomes as well as the standard errors of the estimated means are given. Pat and Mat refer to the paternal and maternal alleles, respectively, determined based on the intron3-nt3072G→A mutation.
FIG. 5B : Electrophoretic mobility shift analyses (EMSA) using 10 μg nuclear extracts (N.E.) from mouse C2C12 myoblast cells, human HEK293 embryonic kidney cells, and human HepG2 hepatocytes. The q and Q oligonucleotide probes corresponded to the wild-type and mutant sequences, respectively. Competition was carried out with a 50-fold excess of cold nucleotide. Complex 1 (C1) was specific and exclusively detected with the q probe. C2 was also specific and stronger in q but probably present also with the Q probe. C3 was unspecific.
FIG. 5C : Luciferase assays of reporter constructs using the TK promoter. The pig IGF2 fragments (Q and q) contained 578 bp from intron 3 (nucleotide 2868 to 3446) including the causative G to A transition at nucleotide 3072. The relative activities compared with the basic TK-LUC vector are reported as means±standard errors based on triplicate experiments. A student's t-test revealed highly significant differences for all pair-wise comparisons; ***=P<0.001.
FIG. 6 : Analysis of IGF2 mRNA expression. (Panel A) Imprinting analysis of IGF2 in skeletal muscle of qq, Q Pat /q Mat , and q Pat /Q Mat animals before birth and at four months of age. The QTL and SWC9 genotypes of the analyzed animals are given. In these, the first allele is paternal, the second maternal. The lanes corresponding to PCR product obtained from genomic DNA are marked by continuous lines, those corresponding to RT-PCR products by the dotted lines. The three SWC9 alleles segregating in the pedigree (1, 2, and 8) are marked by arrows. The RT-PCR controls without reverse transcriptase were negative (not shown). (Panel B) Northern blot analysis of skeletal muscle poly(A) + RNA from three-week-old piglets using IGF2 and GAPDH probes. Animals 1-4 and 5-8 carried a paternal IGF2*Q or *q allele, respectively. P3 and P4 indicate the IGF2 promoter usage and the superscripts a and b indicate the alternative polyadenylation signal used. All four IGF2 transcripts showed a significantly higher relative expression (standardized using GAPDH expression) in the *Q group (P<0.05, Kruskal-Wallis rank sum test, two sided). (Panel C) Results of real-time PCR analysis of IGF2 mRNA expression in skeletal muscle and liver at different developmental phases of pigs carrying paternal IGF2*Q (gray staples) or *q (white staples) alleles. The expression levels were normalized using GAPDH as internal control. Means±SE are given, n=3-11. *=P<0.05, **=P<0.01, Kruskal-Wallis rank sum test, two sided. No significant differences in IGF2 expression levels between genotypes were found in fetal (80 days of gestation) or liver tissues (three weeks). w, week; mo, month.
FIG. 7 : Representation of a suitable marker-assisted selection program for the IGF2 mutation.
DETAILED DESCRIPTION OF THE INVENTION
The invention is further described with the aid of the following illustrative Examples.
EXAMPLES
Example 1
Haplotype Sharing Refines the Location of an Imprinted QTL with Major Effect on Muscle Mass to a 90 Kb Chromosome Segment Containing the Porcine Igf2 Gene
We herein describe the fine-mapping of an imprinted QTL with major effect on muscle mass that was previously assigned to proximal SSC2 in the pig. The proposed approach exploits linkage disequilibrium in combination with QTL genotyping by marker-assisted segregation analysis. By identifying a haplotype shared by all “Q” chromosomes and absent amongst “q” chromosomes, we map the QTL to a ≈90 Kb chromosome segment containing INS and IGF2 as only known paternally expressed genes. QTL mapping has become a preferred approach towards the molecular dissection of quantitative traits, whether of fundamental, medical or agronomic importance. A multitude of chromosomal locations predicted to harbor genes influencing traits of interest have been identified using this strategy (e.g., MacKay 2001; Andersson 2001; Flint and Mott 2001; Mauricio 2001). In most cases, however, the mapping resolution is in the order of the tens of centimorgans, which is insufficient for positional cloning of the underlying genes. High-resolution mapping of QTL, therefore, remains one of the major challenges in the genetic analysis of complex traits.
Three factors limit the achievable mapping resolution: marker density, cross-over density, and the ability to deduce QTL genotype from phenotype. Increasing marker density may still be time consuming in most organisms but is conceptually the simplest bottleneck to resolve. Two options are available to increase the local cross-over density: breed recombinants de novo or exploit historical recombination events, i.e., use linkage disequilibrium (LD). The former approach is generally used with model organisms that have a short generation time (e.g., Darvasi 1998), while the latter is the only practical alternative when working with human or large livestock species. Optimal use of LD to fine-map QTL in outbred populations is presently an area of very active research (e.g., Ardlie et al. 2002). The ability to deduce QTL genotype from phenotype can be improved by using “clones” (e.g., recombinant inbred lines) (e.g., Darvasi 1998), by means of progeny-testing (e.g., Georges et al. 1995), or by marker-assisted segregation analysis (e.g., Riquet et al. 1999).
Recently, a QTL with major effect on muscle mass and fat deposition was mapped to the centromeric end of porcine chromosome SSC2 (Nezer et al. 1999; Jeon et al. 1999). The most likely position of the QTL was shown to coincide with a chromosome region that is orthologous to HSA11p15 in the human, which is known to harbor an imprinted domain. The demonstration that the QTL was characterized by a clear parent-of-origin effect, strongly suggested that the underlying gene was imprinted and expressed only from the paternal allele. The human 11p15 imprinted domain is known to contain at least nine imprinted transcripts. Three of these are paternally expressed: LIT-1 (KVLQT1-AS), IGF2 and IGF2-AS (e.g., Reik and Walter 2001). Fifteen imprinted transcripts are known to map to the orthologous domain on distal mouse chromosome MMU7, of which four are paternally expressed: Lit-1 (Kv1qt1-as), Ins2, Igf2 and Igf2-as (e.g., worldwideweb.mgu.har.mrc.ac.uk/imprinting/imprinting.html; Onyango et al. 2000). Because of its known function in myogenesis (Florini et al. 1996), IGF2 stood out as a prime positional candidate.
To refine the map position of this QTL and to verify whether its position remained compatible with a direct role of the INS and/or IGF2 genes, we applied an approach targeting the three factors limiting the mapping resolution of QTL: (i) we generated a higher-density map of the corresponding chromosome region; (ii) we determined the QTL genotype of a number of individuals by marker-assisted segregation analysis; and (iii) we applied a LD-based haplotype sharing approach to determine the most likely position of the QTL. This approach is analogous to the one that was previously applied by Riquet et al. (1999) to refine the map position of a QTL influencing milk production in dairy cattle. It makes the assumption that the observed QTL effect is due to the segregation of a QTL allele with major substitution effect (“Q”) that appeared by mutation or migration g generations ago, and swept through the populations as a result of artificial selection. As a consequence, at the present generation, n chromosomes carrying the “Q” allele are expected to share a haplotype of size≈2/ng (in Morgan) containing the QTL (Dunner et al. 1997).
By doing so, we have identified a shared haplotype spanning less than 90 Kb that is predicted to contain the Quantitative Trait Nucleotide (QTN: MacKay 2001). The corresponding chromosome segment contains INS and IGF2 as only known paternally expressed genes. This considerably enforces the candidacy of these two genes and demonstrates that LD can be exploited to map QTL in outbred populations to chromosome intervals containing no more than a handful of genes.
Materials and Methods
Pedigree Material and Phenotypic Data
The pedigree material used for this work comprised a subset of previously described Piétrain x Large White F2 pedigrees (Nezer et al., 2000; Hanset et al., 1995), as well as a series of paternal half-sib pedigrees sampled in commercial lines derived from the Piétrain and Large White breeds (Buys, personal communication). In the F2 animals, “% lean cuts” was measured as previously described (Hanset et al., 1995), while in the commercial lines % lean meat was measured as “Piglog” corresponding to (63.6882−0.4465 a −0.5096 b+0.1281 c) where a=mm back fat measured between the third and fourth lumbar vertebra at 7 cm from the spine, b=mm back fat measured between the third and fourth last rib at 7 cm from the spine, and c=mm loin thickness, measured at same position as b.
Marker-Assisted Segregation Analysis
The QTL genotype of each sire was determined from the Z-score, corresponding to the log 10 of the likelihood ratio L H 1 /L H 0 , where L H1 corresponds to the likelihood of the pedigree data assuming that the boar is of “Qq” genotype, and L H 0 corresponds to the likelihood of the pedigree data assuming that the boar is of “QQ” or “qq” genotype. The corresponding likelihoods were computed as:
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σ
2
In this, n is the number of informative offspring in the corresponding pedigree, y i is the phenotype of offspring i, y is the average phenotype of the corresponding pedigree computed over all (informative and non-informative) offspring, σ is the residual standard deviation maximizing L, and a is the Q to q allele substitution effect. a was set at zero when computing L H 0 , and at +1% for “R” offspring and −1% for “L” offspring when computing L H1 (Nezer et al. 1999).
Boars were considered to be “Qq” when Z>2, “QQ” or “qq” when Z<−2 and of undetermined genotype if 2>Z>−2.
Linkage Disequilibrium Analysis
Probabilities for two chromosomes to be identical-by-descent (IBD) at a given map position conditional on flanking marker data were computed according to Meuwissen and Goddard (2001). The effective population size (N e ) was set at 200 based on estimates of N e determined from LD data (Harmegnies, unpublished observations), and the number of generations to the base population at 20. A multipoint test for association was performed using the DISMULT program described in Terwilliger 1995.
Results
QTL genotyping by marker-assisted segregation analysis: We genotyped a series of paternal half-sib families counting at least 20 offspring for two microsatellite markers located on the distal end of chromosome SSC2 and spanning the most likely position of the imprinted QTL: SWR2516 and SWC9 (Nezer et al. 1999; Jeon et al. 1999). These families originated either from a previously described Piétrain x Large White F2 pedigree (Nezer et al. 2002), or from two composite pig lines derived from Large White and Piétrain founder animals (Nadine Buys, personal communication).
The pedigrees from sires that were heterozygous for one or both of these markers were kept for further analysis. Twenty such pedigrees could be identified for a total of 941 animals. Offspring were sorted in three classes based on their marker genotype: “L” (left homologue inherited from the sire), “R” (right homologue inherited from the sire), or “?” (not informative or recombinant in the SWR2516-SWC9 interval).
Offspring were slaughtered at a constant weight of approximately 105 Kgs, and a series of phenotypes collected on the carcasses including “% lean meat,” measured either as “% lean cuts” (experimental cross) or as “Piglog” (composite lines) (see Materials and Methods).
We then computed the likelihood of each sire family under two hypotheses: H 0 , postulating that the corresponding boar was homozygous at the QTL, and H 1 postulating that the boar was heterozygous at the QTL. Assuming a bi-allelic QTL, H 0 corresponds to QTL genotypes “QQ” or “qq,” and H 1 to genotype “Qq.” Likelihoods were computed using “% lean meat” as phenotype (as the effect of the QTL was shown to be most pronounced on this trait in previous analyses), and assuming a Q to q allele substitution effect of 2.0% (Nezer et al. 1999). If the odds in favor of one of the hypotheses were superior or equal to 100:1, the most likely hypothesis was considered to be true. Results are expressed as lod scores (z): the log 10 of the likelihood ratio H 1 /H 0 . Boars were considered to be of heterozygous “Qq” genotype if z was superior to 2, of homozygous “QQ” or “qq” genotype if z was inferior to −2, and of undetermined QTL genotype if −2<z<2.
Using these rules, we could determine the QTL genotype for fourteen of the twenty boars. Seven of these proved to be heterozygous “Qq,” the other seven to be homozygous and thus either of “QQ” or “qq” genotype ( FIG. 1 ). Constructing a physical and genetic map of the porcine orthologue of the human 11p15 imprinted domain:
The SWC9 marker was known from previous studies to correspond to a (CA), microsatellite located in the 3′UTR of the porcine IGF2 gene (Nezer et al. 1999; Jeon et al. 1999; Amarger et al. 2002). We performed a BLAST search with the sequence of the porcine SWR2516 marker (gi|7643973|) against the sequence contigs spanning the human 11p15 imprinted domain worldwideweb.ensembl.org/Homo_sapiens/. A highly significant similarity (expected value of 6×10 −5 calculated based on the size of the NCBI “nr” database) was found between SWR2516 and sequence contig AC001228 (gi|1935053|) at 3.3 Kb of the p57 gene. This suggested that the SWR2516-SWC9 marker interval in the pig might correspond to the p57-IGF2 interval of the human 11p15 imprinted domain.
We then developed porcine sequence tagged sites (STS) across the orthologous region of the human 11p15 imprinted domain. Sixteen of these were developed in genes (TSSC5, CD81, KVLQT1 (3×), TH (2×), INS (3×), IGF2 (3×), H19 (3×)), and five in intergenic regions (IG IGF2-H19 , IG H19-RL23mrp (4×)). The corresponding primer sequences were derived from the porcine genomic sequence when available (Amarger et al. 2002), or from porcine-expressed sequence tags (EST) that were identified by BLAST searches using the human orthologues as query sequences (Table 1).
We screened a porcine BAC library (Fahrenkrug et al. 2001) by filter hybridization using (i) human cDNA clones corresponding to genes known to map to 11p15, as well as (ii) some of the 21 previously described porcine STS. Seven of the identified BACs were shown by PCR to contain at least one of the porcine STS available in the region and were kept for further analysis together with two BACs that were previously shown to span the TH-H19 region (Amarger et al. 2002). Three additional STS were developed from BAC end sequences (389B2T7, 370C17T7, 370SP6). 370SP6 revealed a highly significant BLAST hit (expected value 10 −7 ) downstream from the ASCL2 gene providing an additional anchor point between the human and porcine sequence. Using STS content mapping, we assembled the BAC contig shown in FIG. 2 . It confirms the overall conservation of gene order between human and pigs in this chromosome region and indicates that the gap remaining in the human sequence between the INS and ASCL2 genes may not be larger than 55 Kb.
All available STS were then amplified from genomic DNA of the fourteen QTL genotyped boars (see above) and cycle-sequenced in order to identify DNA sequence polymorphisms. We identified a total of 43 SNPs: two in TSSC5, fifteen in KVLQT1, three in 389B2-T7, four in TH, seven in INS, four in IGF2, one in IG (IGF2-H19) , three in H19 and four in IG (H19-RL23MRP) (Table 1).
Three microsatellites were added to this marker list: one (KVLQT1-SSR) isolated from BAC 956B11 and two (PULGE1 and PULGE3) isolated from BAC 370.
Assembling Pools of “Q” Versus “q” Bearing Chromosomes:
To reconstruct the marker linkage phase of the fourteen QTL genotyped sires, we selected—for each boar—offspring that were homozygous for the alternate paternal SWR2516-SWC9 haplotypes. These were genotyped for all SNPs and microsatellites available in the region, and from these genotypes we manually determined the linkage phase of the boars.
For six of the seven boars, shown by marker-assisted segregation analysis to be of “Qq” genotype ( FIG. 1 ), the “Q” chromosomes associated with an increase in % lean meat proved to be identical-by-state (IBS) over their entire length. This haplotype was, therefore, referred to as “Q 1 .” The haplotype corresponding to the seventh “Q” chromosome (P7 in FIG. 2 ) was different and referred to as “Q 2 .” For three of these sires, the haplotypes associated with a decrease in % lean meat proved to be completely IBS as well, and were thus referred to as “q 1 .” The other four “q” chromosomes carried distinct haplotypes, and were referred to as “q 2 ,” “q 3 ,” “q 4 ” and “q 5 ” ( FIG. 2 ). The first boar that proved to be homozygous for the QTL by marker-assisted segregation analysis (P8) carried the “q 4 ” haplotype on one if its chromosomes. Its other haplotype, therefore, had to be of “q” genotype as well and was referred to as “q 6 .”
Boar P9 appeared to be heterozygous “Q 1 /Q 2 .” Boars P10 and P11 carried the “Q 1 ” haplotype shared by six of the “Qq” boars. As a consequence, the other chromosomes of boars P10 and P11, which were IBS as well, were placed in the “Q” pool and referred to as “Q 3 .” Homozygous boar P12 carried haplotype “Q 2 .” As a consequence, its homologue was referred to as “Q 4 .” Following the same recursive procedure, boars P13 and P14 were identified as being, respectively, “Q 3 Q 4 ” and “Q 2 Q 5 .”
The marker genotypes of the resulting five “Q” and five “q” chromosomes are shown in FIG. 2 . In this figure, closely linked (<5 Kb) SNPs were merged into a series of polyallelic multisite haplotypes. The correspondence between SNP genotype and haplotype number is given in Table 2.
All “Q” chromosomes share a ≈90 Kb common haplotype encompassing the INS and IGF2 genes not present in the “q” chromosomes. Visual examination of the “Q” and “q” pools immediately reveals that all five chromosomes in the “Q” pool indeed share an IBS haplotype spanning the 389B2T7-IGF2 interval ( FIG. 2 ). Four of the five “Q” chromosomes (“Q 1 ,” “Q 2 ,” “Q 3 ” and “Q 4 ”) also carry a common haplotype in the proximal KVLQT1(I12)-(I7) interval, while the fifth one (“Q 5 ”) carries a completely different KVLQT1(I12)-(I7) haplotype. This strongly suggests an ancestral recombination between KVLQT1(I7) and 389B2T7. Likewise, three of the five “Q” chromosomes (“Q 1 ,” “Q 3 ,” “Q 4 ”) carry the same haplotype distal from IGF2, while the two remaining ones (“Q 2 ,” “Q 5 ”) are sharing a completely distinct one. Again, this is best explained by assuming an ancestral recombination event just proximal from the SWC9 microsatellite marker. These observations, therefore, strongly suggest that the hypothesized “Q” allele associated with an increase in “% lean meat” appeared by mutation or migration on a founder chromosome carrying the haplotype highlighted in FIG. 2 , and that the QTL is located in the KVLQT1(I7)-SWC9 interval. At present, our best estimate of the size of this interval is of the order of 500 Kb ( FIG. 2 ).
No such shared haplotype could be identified in the “q” pool. As expected under our model, the “q” pool exhibited a higher level of genetic diversity. The “q” bearing chromosomes would indeed be older, having had ample opportunity to recombine, thereby increasing haplotype diversity. This can be quantified more accurately by computing the average pair-wise probability for “Q” and “q” chromosomes to be IBD conditional on flanking marker data, using the coalescent model developed by Meuwissen and Goddard (2001). As shown in FIG. 3 , the average pair-wise IBD probability amongst the five “Q” chromosomes is superior to 0.4 over the entire KVLQT1(SSR)-IG (H19-RL23mrp) interval and exceeds 0.9 in the PULGE3-IGF2 interval. For the “q” chromosomes, the equivalent parameter averages 0.25 in the same region. It is worthwhile noting, however, that even amongst “q” chromosomes, the average pair-wise IBD probability peaks just above 0.4 between TH and INS, which is thought to reflect a “q”-specific haplotype signature.
It is noteworthy that chromosome “q 4 ” carries a KVLQT1(I12)-PULGE3 haplotype that is IBS with the ancestral “Q” haplotype in the KVLQT1(I12)-PULGE3 interval. The probability that this IBS status reflects IBD was estimated at ≈0.50 using the coalescent model of Meuwissen and Goddard (2001). Assuming IBD, this would position the QTL in the PULGE3-SWC9 interval, measuring less than 90 Kb and containing TH, INS and IGF2 as only known genes.
One could argue that the probability to identify a shared haplotype amongst five chromosomes by chance alone is high and does not support the location of the QTL within this region. To more quantitatively estimate the significance of the haplotype sharing amongst “Q” chromosomes, accounting for the distance between adjacent markers as well as allelic frequencies, we, therefore, performed a multipoint LD analysis using the DISMULT program (Terwilliger 1995). To test the significance of the haplotype sharing observed amongst the five “Q” chromosomes, we performed the same DISMULT analysis on all 462 possible combinations of the 11 chromosomes taken five at a time. For each of these analyses, we stored the highest likelihood obtained anywhere along the analyzed chromosome segment. The likelihood obtained using the real five “Q” chromosomes at the position of marker PULGE3 was the highest one obtained across all chromosome permutations (data not shown), clearly indicating that the observed haplotype sharing is very unlikely to be fortuitous.
When we previously demonstrated that only the paternal SSC2 QTL allele influenced muscle mass and that the most likely QTL position coincided with IGF2, this gene obviously stood out as the prime candidate (Nezer et al. 1999; Jeon et al. 1999). On the basis of the initial linkage analysis, however, the confidence interval for the QTL covered approximately 4 cM, which were bound to contain a multitude of genes other than IGF2. It was, therefore, useful to corroborate these papers by refining the map position of the QTL, which we set out to do by exploiting both LD and marker-assisted segregation analysis. Because of the observed parent-of-origin effect, we focused our analysis on a chromosome region that is the ortholog of the human 11p15 imprinted domain. We herein provide strong evidence that the QTL indeed maps to the p57-H19 imprinted gene cluster, and within this region to a chromosome segment of ≈90 Kb known to contain the TH, INS and IGF2 genes. These findings, therefore, considerably strengthen the candidacy of IGF2, and justify a detailed analysis of this gene.
The fact that we succeeded in refining the map position of this QTL down to the subcentimorgan level, supports its simple molecular architecture. Together with recent successes in positional cloning and identification of the mutations that underlie QTL (e.g., Grobet et al. 1997; Milan et al. 2001; Grisart et al. 2002; Blott et al. 2002), this clearly indicates that at least part of the genetic variation of production traits in livestock is due to single mutations with large effects on the traits of interest.
The success of haplotype sharing approaches in fine-mapping QTL in livestock also suggests that QTL may be mapped in these populations by virtue of the haplotype signature resulting from intense selection on “Q” alleles, i.e., haplotypes of unusual length given their population frequency. The feasibility of this approach has recently been examined in human populations for loci involved in resistance to malaria (Sabeti et al. 2002). QTL could thus be identified in livestock in the absence of phenotypic data.
Example 2
Positional Identification of a Regulatory Mutation in IGF2 Causing a Major QTL Effect on Muscle Development in the Pig
The identification of causative mutations for Quantitative Trait Loci (QTLs) is a major hurdle in genetic studies of multifactorial traits and disorders. Here, we show that a paternally expressed QTL affecting muscle mass and fat deposition in pigs is caused by a single nucleotide substitution in intron 3 of IGF2. The mutation occurs in an evolutionary conserved CpG island that is hypomethylated in skeletal muscle. Pigs carrying the mutation have a three-fold increase in IGF2 mRNA expression in postnatal muscle. The mutation abrogates in vitro interaction with a nuclear factor, most likely a repressor. The mutation has experienced a selective sweep in several pig breeds. The study provides an outstanding example where the causal relationship between a regulatory mutation and a QTL effect has been established.
The imprinted IGF2-linked QTL is one of the major porcine QTLs for body composition. It was first identified in intercrosses between the European Wild Boar and Large White domestic pigs and between Piétrain and Large White pigs. (1, 2) The data showed that alleles from the Large White and Piétrain breed, respectively, were associated with increased muscle mass and reduced back-fat thickness, consistent with the existing breed-differences in the two crosses. A paternally expressed IGF2-linked QTL was subsequently documented in intercrosses between Chinese Meishan and Large White/Landrace pigs (3) and between Berkshire and Large White pigs. (4) In both cases, the allele for high muscle mass was inherited from the lean Large White/Landrace breed.
We have recently used a haplotype sharing approach to refine the map position of the QTL. (5) We assumed that a new allele (Q) promoting muscle development occurred g generations ago on a chromosome carrying the wild-type allele (q). We also assumed that the favorable allele has gone through a selective sweep due to the strong selection for lean growth in commercial pig populations. Twenty-eight chromosomes with known QTL status were identified by marker-assisted segregation analysis using cross-bred Piétrain and Large White boars. All 19 Q-bearing chromosomes shared a haplotype in the 90 kilobase pairs (kb) interval between the microsatellites PULGE1 and SWC9 (IGF2 3′-UTR), which was not present among the q chromosomes and was, therefore, predicted to contain the QTL. In contrast, the nine q chromosomes exhibited six distinct marker haplotypes in the same interval. This region is part of the CDKN1C-H19 imprinted domain and contains INS and IGF2 as the only known paternally expressed genes. Given the known functions of these genes and especially the role of IGF2 in myogenesis, (6) they stood out as prime positional candidates. A comparative sequence analysis of the porcine INS-IGF2 region revealed as many as 59 conserved elements (outside known exons) between pig and human, all being candidate regions for harboring the causative mutation. (7)
In order to identify the causative mutation, we re-sequenced one of the 19 Q-chromosomes (P208) and six q-chromosomes (each corresponding to one of the six distinct marker haplotypes) for a 28.6 kb segment containing IGF2, INS, and the 3′ end of TH. This chromosome collection was expanded by including Q- and q-chromosomes from (i) a Wild Boar/Large White intercross segregating for the QTL, (2) (ii) a Swedish Landrace boar showing no evidence for QTL segregation in a previous study, (8) (iii) F 1 sires from a Hampshire/Landrace cross showing no indication for QTL segregation, (9) and (iv) an F 1 sire from a Meishan/Large White intercross. A Japanese Wild Boar was included as a reference for the phylogenetic analysis; the QTL status of this animal is unknown but we assume that it is homozygous wild-type (q/q). We identified a total of 258 DNA sequence polymorphisms corresponding to a staggering one polymorphic nucleotide per 111 base pairs (bp) ( FIG. 4A ). The sequences formed three major and quite divergent clusters ( FIG. 4B ). The only exception to this pattern was one Hampshire haplotype (H254) that was apparently recombinant.
The two established Q haplotypes from Piétrain and Large White animals (P208 and LW3) were identical to each other and to the chromosomes from the Landrace (LRJ) and Hampshire/Landrace (H205) animals for almost the entire region, showing that the latter two must be of Q-type as well. The absence of QTL segregation in the offspring of the F 1 Hampshire×Landrace boar carrying the H205 and H254 chromosomes implies that the latter recombinant chromosome is also of Q-type. This places the causative mutation downstream from IGF2 intron 1, the region for which H254 is identical to the other Q chromosomes. The Large White chromosome (LW197) from the Meishan/Large White pedigree clearly clustered with q chromosomes, implying that the F 1 sire used for sequencing was homozygous q/q as a previous QTL study showed that the Meishan pigs carried an IGF2 allele associated with low muscle mass. (3) Surprisingly, the Meishan allele (M220) was nearly identical to the Q chromosomes but with one notable exception, it shared a G nucleotide with all q chromosomes at a position (IGF2-intron3-nt3072) where all Q chromosomes have an A nucleotide ( FIG. 4A ).
Under a bi-allelic QTL model, the causative mutation would correspond to a DNA polymorphism for which the two alleles segregate perfectly between Q- and q-chromosomes. The G to A transition at IGF2-intron3-nt3072 is the only polymorphism fulfilling this criterion, implying that it is the causative Quantitative Trait Nucleotide (QTN). (10) We have so far tested 12 large sire families where the sire is heterozygous AG at this position and all have showed evidence for QTL segregation. In contrast, we have tested more than 40 sires, representing several different breeds, genotyped as homozygous A/A or G/G at this position without obtaining any significant evidence for the segregation of a paternally expressed QTL at the IGF2 locus. The results provide conclusive genetic evidence that IGF2-intron3-nt3072G→A is the causative mutation.
IGF2-intron3-nt3072 is part of an evolutionary conserved CpG island of unknown function, (7) located between Differentially Methylated Region 1 (DMR1) and a matrix attachment region previously defined in mice. (11-13) The 94 bp sequence around the mutation shows about 85% sequence identity to both human and mouse, and the wild-type nucleotide at IGF2-intron3-nt3072 is conserved among the three species ( FIG. 4A ). The QTN occurs three bp downstream of an eight bp palindrome also conserved between the three species. The methylation status of the 300 bp fragment centered on IGF2-intron3-nt3072 and containing 50 CpG dinucleotides was examined by bisulphite sequencing in four month old Q pat /q mat and q pat /Q mat animals. In skeletal muscle, paternal and maternal chromosomes were shown to be essentially unmethylated (including the IGF2-intron3-nt3071 C residue) irrespective of the QTL genotype of the individual (3.4% of CpGs methylated on average; FIG. 5A ). The CpG island was more heavily and also differentially methylated in liver, 33% of the CpGs were methylated on the maternal alleles versus 19% on the paternal allele. Unexpectedly, therefore, this CpG island behaves as a previously unidentified DMR in liver, the repressed maternal allele being more heavily methylated than the paternal allele, which is the opposite of what is documented for the adjacent DMR1 in the mouse.
To uncover a possible function for this element, we performed electrophoretic mobility shift analyses (EMSA) using oligonucleotide probes spanning the QTN and corresponding to the wild-type (q) and mutant (Q) sequences. Nuclear extracts from murine C2C12 myoblast cells, human HEK293 cells, and human HepG2 cells were incubated with radioactively labeled q or Q oligonucleotides. One specific band shift (complex C1 in FIG. 5B ) was obtained with the wild-type (q) but not the mutant (Q) probe using extracts from C2C12 myoblasts; similar results were obtained using both methylated and unmethylated probes. A band shift with approximately the same migration, but weaker, was also detected in extracts from HEK293 and HepG2 cells. The specificity of the complex was confirmed since competition was obtained with ten-fold molar excess of unlabeled q probe, whereas a 50-fold excess of unlabeled Q probe did not achieve competition ( FIG. 5B ). Thus, the wild-type sequence binds a nuclear factor, and this interaction is abrogated by the mutation.
To further characterize the functional significance of the IGF2 Q mutation, we studied its effect on transcription by employing a transient transfection assay in mouse C2C12 myoblasts. We made Q and q constructs containing a 578 bp fragment from the actual region inserted in front of a Luciferase reporter gene driven by the herpes thymidine kinase (TK) minimal promoter. The two constructs differed only by the IGF2-intron3-nt3072G→A transition. The ability of the IGF2 fragments to activate transcription from the heterologous promoter was compared with the activity of the TK-promoter alone. The presence of the q-construct caused a two-fold increase of transcription, whereas the Q-construct caused a significantly higher, seven-fold, increase ( FIG. 5C ). Our interpretation of this result, in light of the results from the EMSA experiment, is that the Q mutation abrogates the interaction with a repressor protein that modulates the activity of a putative IGF2 enhancer present in this CpG island. This view is consistent with our in silico identification of potential binding sites for both activators and repressors in this intronic DNA fragment. (14)
The in vivo effect of the mutation on IGF2 expression was studied in a purpose-built Q/q×Q/q intercross counting 73 offspring. As a deletion encompassing DMR0, DMR1, and the associated CpG island derepresses the maternal IGF2 allele in mesodermal tissues in the mouse, (12) we tested the effect of the intron3-nt3072 mutation on IGF2 imprinting in the pig. This was achieved by monitoring transcription from the paternal and maternal IGF2 alleles in tissues of q/q, Q pat /q mat , and q pat /Q mat animals that were heterozygous for the SWC9 microsatellite located in the IGF2 3′UTR. Imprinting could not be studied in Q/Q animals, which were all homozygous for SWC9. Before birth, IGF2 was shown to be expressed exclusively from the paternal allele in skeletal muscle and kidney, irrespective of the QTL genotype of the fetuses. At four months of age, weak expression from the maternal allele was observed in skeletal muscle, however, at comparable rates for all three QTL genotypes ( FIG. 6 , Panel A). Only the paternal allele could be detected in four-month-old kidney (data not shown). Consequently, the mutation does not seem to affect the imprinting status of IGF2. The partial derepression of the maternal allele in skeletal muscle of all QTL genotypes may, however, explain why in a previous study muscular development was found to be slightly superior in q pat /Q mat versus q/q animals, and in Q/Q versus Q pat /q mat animals. (2)
The Q allele was expected to be associated with an increased IGF2 expression since IGF2 stimulates myogenesis. (6) To test this, we monitored the relative mRNA expression of IGF2 at different ages in the Q/q×Q/q intercross using both Northern blot analysis and real-time PCR ( FIG. 6 , Panels B and C). The expression levels in fetal muscle and postnatal liver was about ten-fold higher than in postnatal muscle. No significant difference was observed in fetal samples or in postnatal liver samples, but a significant three-fold increase of postnatal IGF2 mRNA expression in skeletal muscle was observed in (Q/Q or Q pat /q mat ) versus (q pat /Q mat or q/q) progeny. The significant difference in IGF2 expression revealed by real-time PCR was confirmed using two different internal controls, GAPDH ( FIG. 6 , Panel C) and HPRT. (15) We found an increase of all detected transcripts originating from the three promoters (P2-P4) located downstream of the mutated site. Combined, these results provide strong support for IGF2 being the causative gene. The lack of significant differences in IGF2 mRNA expression in fetal muscle and postnatal liver are consistent with our previous QTL study showing no effect of the IGF2 locus on birth weight and weight of liver.(2)
There has been a strong selection for lean growth (high muscle mass and low fat content) in commercial pig populations in Europe and North America during the last 50 years. Therefore, we investigated how this selection pressure has affected the allele frequency distribution of the IGF2 QTL. The causative mutation was absent in a small sample of European and Asian Wild Boars and in several breeds that have not been strongly selected for lean growth (Table 1). In contrast, the causative mutation was found at high frequencies in breeds that have been subjected to strong selection for lean growth. The only exceptions were the experimental Large White population at the Roslin Institute that was founded from commercial breeding stock in the UK around 1980, (16) as well as the experimental Large White populations used for the Piétrain/Large White intercross; (1) these two populations thus reflect the status in some commercial populations about 20 years ago and it is possible that the IGF2*Q allele is even more predominant in contemporary populations. The results demonstrate that IGF2*Q has experienced a selective sweep in several major commercial pig populations and it has apparently been spread between breeds by cross-breeding.
The results have important practical implications. The IGF2*Q mutation increases the amount of meat produced, at the expense of fat, by 3 to 4 kg for an animal slaughtered at the usual weight of about 100 kg. The high frequency of IGF2*Q among major pig breeds implies that this mutation affects the productivity of many millions of pigs in the Western world. The development of a simple diagnostic DNA test now facilitates the introgression of this mutation to additional breeds. This could be an attractive way to improve productivity in local breeds as a measure to maintain biological diversity. The diagnostic test will also make it possible to investigate if the IGF2*Q mutation is associated with any unfavorable effects on meat quality or any other trait. We and others have previously demonstrated that European and Asian pigs were domesticated from different subspecies of the Wild Boar, and that Asian germplasm has been introgressed into European pig breeds. (17) The IGF2*Q mutation apparently occurred on an Asian chromosome as it showed a very close relationship to the haplotype carried by Chinese Meishan pigs. This explains the large genetic distance that we observed between Q- and q-haplotypes ( FIG. 4 ). However, it is an open question whether the Q mutation occurred before or after the Asian chromosome was introduced into European pigs.
This study provides new insights in IGF2 biology. The role of IGF2 on prenatal development is well documented. (18, 19) Our observation that the Q mutation does not up-regulate IGF2 expression in fetal tissue until after birth, which demonstrates that IGF2 has an important role for regulating postnatal myogenesis. The finding that the sequence around the mutation does not match any known DNA-binding site suggests that this sequence may bind an unknown nuclear factor. (14) Our results also mean that pharmacological intervention of the interaction between this DNA segment and the corresponding nuclear factor opens up new strategies for promoting muscle growth in human patients with muscle deficiencies or for stimulating muscle development at the cost of adipose tissue in obese patients.
Materials and Methods
DNA Sequencing
Animals that were homozygous for 13 of the haplotypes of interest were identified using flanking microsatellite markers and pedigree information. A 28.6 kb chromosome segment containing the last exon of TH, INS, and IGF2 was amplified from genomic DNA in seven long-range PCR products using the Expand Long Template PCR system (Roche Diagnostics GmbH). The same procedure was used to amplify the remaining M220 and LW197 haplotypes from two BAC clones isolated from a genomic library that was made from a Meishan/Large White F 1 individual. (20) The long template PCR products were subsequently purified using Geneclean (Polylab) and sequenced using the Big Dye Terminator Sequencing or dGTP Big Dye Terminator kits (Perkin Elmer). The primers used for PCR amplification and sequencing are available as supplementary information. The sequence traces were assembled and analyzed for DNA sequence polymorphism using the Polyphred/Phrap/Consed suite of programs. (21)
SNP Analysis of IGF2-Intron3-Nt3072
The genotype was determined by pyrosequencing with a Luc 96 instrument (Pyrosequencing AB). A 231 bp DNA fragment was PCR amplified using Hot Star Taq DNA polymerase and Q-Solution (QIAGEN) with the primers pyro18274F (5′-Biotine-GGGCCGCGGCTTCGCCTAG-3′) (SEQ ID NO:2) and pyro18274R (5′-CGCACGCTTCTCCTGCCACTG-3′) (SEQ ID NO:3) The sequencing primer (pyro18274seq: 5′-CCCCACGCGCTCCCGCGCT-3′) (SEQ ID NO:4) was designed on the reverse strand because of a palindrome located 5′ to the QTN.
Electrophoretic Mobility Shift Analyses (EMSA)
DNA-binding proteins were extracted from C2C12, HEK293, and HepG2 cells as described. (22) Gel shift assays were performed with 40 fmole 32 P-labeled ds-oligonucleotide, 10 μg nuclear extract, and 2 μg poly dI-dC in binding buffer (15 mM Hepes pH 7.65, 30.1 mM KCl, 2 mM MgCl 2 , 2 mM spermidine, 0.1 mM EDTA, 0.63 mM DTT, 0.06% NP-40, 7.5% glycerol). For competition assays, a ten-fold, 20-fold, 50-fold, and 100-fold molar excess of cold ds-oligonucleotide were added. Reactions were incubated for 20 minutes on ice before 32 P-labeled ds-oligonucleotide was added. Binding was then allowed to proceed for 30 minutes at room temperature. DNA-protein complexes were resolved on a 5% native polyacrylamide gel run in TBE 0.5× at room temperature for two hours at 150 V and visualized by autoradiography. The following two oligonucleotides were used: Q/q: 5′-GATCCTTCGCCTAGGCTC(A/G)CAGCGCGGGAGCGA-3′ (SEQ ID NO: 1).
Northern Blot Analysis and Real-Time RT-PCR
Total RNA was prepared from porcine muscle (gluteus) and liver tissues using Trizol (Invitrogen) and treated with DNase I (Ambion). The products from the first-strand cDNA synthesis (Amersham Biosciences) were column purified with QIAQUICK® columns (Qiagen). Poly (A) + RNA was purified from total RNA using the Oligotex mRNA kit (Qiagen). Approximately 75 ng poly(A) + mRNA from each sample was separated by electrophoresis in a MOPS/formaldehyde agarose gel and transferred onto a Hybond-N+ nylon membrane (Amersham Biosciences). The membrane was hybridized with pig-specific IGF2 and GAPDH cDNA probes using ExpressHyb hybridization solution (Clontech). The quantification of the transcripts was performed with a Phosphor Imager 425 (Molecular Dynamics). Real-time PCR were performed with an ABI PRISM 7700 Sequence Detection System (Applied Biosystems). TaqMan probes and primers were designed with the Primer Express software (version 1.5); primer and probe sequences are available as supplementary material. PCR reactions were performed in triplicate using the Universal PCR Master Mix (Applied Biosystems). The mRNA was quantified as copy number using a standard curve. For each amplicon, a ten point calibration curve was established by a dilution series of the cloned PCR product.
Bisulphite-Based Methylation Analysis
Bisulphite sequencing was performed according to Engemann et al. (23) Briefly, high molecular weight genomic DNA was isolated from tissue samples using standard procedures based on proteinase K digestion, phenol-chloroform extraction, and ethanol precipitation. The DNA was digested with EcoRI, denatured, and embedded in low melting point agarose beads. Non-methylated cytosine residues were converted to uracil using a standard bisulphite reaction. The region of interest was amplified using a two-step PCR reaction with primers complementary to the bisulphite converted DNA sequence (PCR1-UP: 5′-TTGAGTGGGGATTGTTGAAGTTTT-3′ (SEQ ID NO:7), PCR1-DN: 5′-ACCCACTTATAATCTAAAAAAATAATAAATATATCTAA-3′ (SEQ ID NO:8), PCR2-UP: 5′-GGGGATTGTTGAAGTTTT-3′ (SEQ ID NO:9), and PCR2-DN: 5′-CTTCTCCTACCACTAAAAA-3′) (SEQ ID NO:10). The amplified strand was chosen in order to be able to differentiate the Q and q alleles. The resulting PCR products were cloned in the pCR2.1 vector (Invitrogen). Plasmid DNA was purified using the modified Plasmid Mini Kit (QIAGEN) and sequenced using the Big Dye Terminator Kit (Perkin Elmer) and an ABI3100 sequence analyzer.
Transient Transfection Assay
C2C12 myoblast cells were plated in six-well plates and grown to ˜80% confluence. Cells were transiently co-transfected with a Firefly luciferase reporter construct (4 μg) and a Renilla luciferase control vector (phRG-TK, Promega; 80 ng) using 10 μg Lipofectamine 2000 (Invitrogen). The cells were incubated for 24 hours before lysis in 100 μl Triton Lysis Solution. Luciferase activities were measured with a Mediators PhL luminometer (Diagnostic Systems) using the Dual-Luciferase reporter Assay System (Promega).
Analysis of the IGF2 Imprinting Status
RT-PCR analysis of the highly polymorphic SWC9 microsatellite (located in IGF2 3′UTR) was used to determine the IGF2 imprinting status. The analysis involved progeny groups from heterozygous sires. Total RNA was extracted from the gluteus muscle using Trizol Reagent (Life Technology), and treated with RNase-free DNase I (Roche Diagnostics GmbH). cDNA was synthesized using the 1 st Strand cDNA Synthesis Kit (Roche Diagnostics GmbH). The SWC9 marker was amplified using the primers UP (5′-AAGCACCTGTACCCACACG-3′) (SEQ ID NO: 11) and DN (5′-GGCTCAGGGATCCCACAG-3′) (SEQ ID NO: 12). The 32 P-labeled RT-PCR products were separated by denaturing PAGE and revealed by autoradiography.
Example 3
The Mutation has an Effect on Teat Number
Sires of two commercial lines were genotyped for the mutation. Shortly after birth, the number of teats was counted on all piglets. Piglet counts ranged from 12 to 18 teats and included 4477 individuals from 22 sires. A statistical analysis of teat number in piglets was performed by accounting for the following effects: 1) genetic line (lines A and B), 2) genotype of the sire for the mutation (QQ, Qq or qq) and 3) sex of the piglet (male/female). Analysis of variance was performed using Proc Mixed (SAS) assuming normality of dependent variable teat number. Estimates of some contrasts are given in Table 4.
The effect of genotype on teat number in piglets is −0.28 teats. This effect is opposite to the one described by Hirooka et al. 2001. An effect of genetic line could not be demonstrated. The sex of the piglet had a significant effect on teat number with female pigs having an average of 0.05 teat more than males. Mean values per genotype and per line are given in Table 5.
The statistical analysis confirms that the mutation influences teat number. The Q allele that is favorable with respect to muscle mass and reduced back fat is the unfavorable allele for teat number. This strengthens the possibility of using the paternal imprinting character of this QTL in breeding programs. Selecting maternal lines for the q allele will enhance teat number, a characteristic that is favorable for the maternal side. On the other hand, paternal lines can be selected for the Q allele that will increase muscle mass and reduce back fat, characteristics that are of more importance in the paternal lines. Terminal sires that are homozygous QQ will pass the full effect of increased muscle mass and reduced back fat to the slaughter pigs, while selection of parental sows that express the q allele will have more teats without affecting slaughter quality.
Example 4
The Mutation has an Effect on Sow Longevity and Sow Prolificacy
This example shows the presently described unique inheritance method of paternal imprinting, wherein only the gene inherited from the father is expressed, and wherein the gene inherited from the mother is a silent gene and has no effect on the carcass quality of the offspring.
Materials and Methods
Animals. The animals used in this experiment are purebred animals belonging to three different closed dam lines based on Large White and Landrace breeds. From 1999 until 2005, blood samples were collected from all nucleus sows and boars. Genotypic frequencies per line were calculated on 555 sows in total.
Measurements. Individual blood samples are linked to individual phenotypes. For all sows, the following parameters were recorded: total born, live born, stillborn and weaned piglets per litter. At test weight of 110 kg, carcass measures were performed on live animals using Piglog 105 (including back fat 1, back fat 2 (3rd-4th rib), loin eye depth and lean meat percentage).
Genotyping. DNA was extracted from the pig blood samples using the Wizard Genomic DNA purification kit according to procedures provided by the manufacturer (Promega, Madison Wis., USA). An allelic discrimination assay was performed using the ABI Prism 7700 sequence detection system (Applied Biosystems). The final concentrations used in the 5 μl master mix were: 2.5 μl Taqman Universal PCR Master Mix, NoAmpErase Ung (Applied Biosystems, Foster City, Calif., USA), 1× Assay Mix, 10 ng DNA and 2,375 μl H 2 O, Foster City, USA).
Statistical analyses. The statistical analysis was performed using the statistical software SAS. The gene frequencies were calculated from PROC FREQ. IGF2 effects were analyzed using SAS PROC GLM with paternal or maternal allele as class variables and taking into account parity and sire. For the calculation of the effect of the IGF2 mutation on the traits measured, a subset of data was made in which only sows that originate from sires that are heterozygous for the IGF2 mutation were used. Sows that inherited the G allele were compared with those that inherited the A allele. Another subset of data was made in which only sows from heterozygous dams were retained. In this dataset, the effect of the maternal allele was analyzed.
Results and Discussion. Allelic frequencies are presented in Table 6. All three dam lines segregate for the IGF2 mutation, although frequencies differ according to the line.
A subset of data was made in which only sows derived from heterozygous sires that segregate in the population were retained. A comparison was made between sows that inherited the A or the G allele from their father.
Sows that inherited the wild-type allele from their father had significantly more piglets born alive, total born and weaned, while there was no effect on stillborn piglets (Table 7). If the same dataset was analyzed, according to the allele inherited from the mother (maternal allele), no effect on any of these prolificacy data could be observed. A second subset of data was created in which only sows from heterozygous dams were taken into account and grouped according to the maternal allele. Again, no significant effect on prolificacy could be observed, which was expected since the maternal allele is not expressed.
The parity or average number of cycles per sow was also higher in sows that inherited G from their father as compared to those that received the A allele, which points to a beneficial effect on longevity. This is related to higher litter size, since that is a major criterion for elimination in the selection program.
The effect of the paternal allele for IGF2 was also analyzed on conformation measures at ca. 110 kg live weight. These data are presented in Table 8.
Although no significant effects of IGF2 paternal allele on Piglog results could be observed, there is a tendency towards higher muscularity and lower back fat in the sows that inherited the A allele from their father. The fact that this difference is not significant could be due to the low number of animals on the one hand and the use of a threshold value on back fat in the selection program on the other.
These results show an influence of the IGF2-intron3 G3072A mutation on prolificacy and longevity in sows. This opens the possibilities to use the same imprinted QTN for different selection in sire and dam lines. Terminal sires should be homozygous for the lean allele to give uniform and lean slaughter pigs, while dam lines can benefit from a selection for the wild-type allele since this has a beneficial effect on prolificacy and longevity. Because of the imprinted character of the gene, selection for the fatter allele in sow lines will not influence the carcass quality of the offspring.
A suitable marker-assisted selection program for the IGF2 mutation may now be represented as depicted in FIG. 1 .
TABLE 1
Utilized sequence tagged sites (STS) and corresponding DNA sequence polymorphisms (DSP).
STS
Source
UP-primer (5′–3′)
DN-primer (5′–3′)
DSP 2
DSP (5′–3′)
TSSC5(I1) 1
BI183986
TCATCCAGGGCCTGGTCAT
TGTCTGAGGCCGACACGGCC
T1
CCCCCT(C/T)GGCCCCC
CG (SEQ ID NO: 13)
(SEQ ID NO: 14)
(SEQ ID NO: 15)
T2
ACCCAGGGC(C/T)CCTTGAG
(SEQ ID NO: 16)
SWR2516
gi7643973
GTGCATTATCGGGAGGTA
ACCCTGTATGATACTGTAACTC
SSR
ATAGGGTTA(GT)nAGATCAGTC
TG (SEQ ID NO: 17)
TGG (SEQ ID NO: 18)
(SEQ ID NO: 19)
KVLQT1(SSR)
BAC956B11
CTTTGAGGTCCATCATGTT
GGACGTACATCCCATCGATGA
SSR
CCA (SEQ ID NO: 20)
(SEQ ID NO: 21)
KVLQT1(I12)
BF198846
ATGGTTGTCCTCTGCGTGG
TGGCGGTCGACGTGCAGCATC
T1
TGGGTGGGGG(C/T)GCAGCCCC
GC (SEQ ID NO: 22)
(SEQ ID NO: 23)
(SEQ ID NO: 24)
T2
GCTGGGA(C/T)CAGACC(G/A)TCTG
GG (SEQ ID NO: 25)
T3
GCTGGGA(C/T)CAGACC(G/A)TCTG
GG (SEQ ID NO: 25)
T4
CTGTCTGCTCAT(C/T)CGGGGGCTG
(SEQ ID NO: 26)
T5
GGCTGCGGGAGC(C/T)TGGGGCCAC
(SEQ ID NO: 27)
T6
GCCACCCCC(C/T)TGACCCTGA
(SEQ ID NO: 28)
KVLQT1(I11)
BF198846
ATCCGCTTCCTCCAGATCC
GCCGATGTACAGCGTGGTGA
V1
TCTGGGCCGG(G/T)GTCCCCG
TG (SEQ ID NO: 29)
(SEQ ID NO: 30)
(SEQ ID NO: 31)
T1
AAAAGGGTCC(A/G)GGAAGCT
(SEQ ID NO: 32)
T2
TTGCAAACAGC(C/T)CCCAGAAGG
(SEQ ID NO: 33)
T3
AGAAGGCGCAG(C/T)CTCCACGGG
(SEQ ID NO: 34)
T4
AGGGGCGCTGG(C/T)TGCAGGGGTG
(SEQ ID NO: 35)
T5
TTTATGAGTC(A/G)CAAAAACGAG
(SEQ ID NO: 36)
T6
TGATGTCCGCC(C/T)(G/T)GGCAGA
CT (SEQ ID NO: 37)
V2
TGATGTCCGCC(C/T)(G/T)GGCAGA
CT (SEQ ID NO: 37)
KVLQT1(I7)
BF198846
GCCCCAAGCCCAAGAAGTC
CCAGAATTGTCACAGCCATCC
T
TCCGGGGCAT(A/G)TAGGACTGG
TG (SEQ ID NO: 38)
(SEQ ID NO: 39)
(SEQ ID NO: 40)
389B2T7
BAC389B2
GGAGTACCTGCTGTGGCTT
CGTCCTATATCCATCAGGAATA
T1
AGTAGTAT(C/T)CATGAGCAC
AGTG (SEQ ID NO: 41)
TTG (SEQ ID NO: 42)
(SEQ ID NO: 43)
T2
CCCAGGCCTC(G/A)ATCAGCTGGTTG
(SEQ ID NO: 44)
V
TATATGCCA(C/A)ACATGTGGCCCT
(SEQ ID NO: 45)
CD81(I3)
F23061
GGGGCCATCCAGGAGTCAC
CAAAGAGGATCACGAGGCAGG
AG (SEQ ID NO: 46)
(SEQ ID NO: 47)
INRA370SP6
BACINRA370
TGCGTAGCCATGGCGATGG
AGTGTGGAACCCTGGGGGGGGA
GG (SEQ ID NO: 48)
AGG (SEQ ID NO: 49)
370C17T7
BAC370C17
AGAGGGTACAGAAGCCCTG
TTTGGTGTGGTGTCTGCTGAC
(SEQ ID NO: 50)
CC (SEQ ID NO: 51)
PULGE3
BACINRA370
AGGCTTTCTATCTGCAGGA
ACCGTGTGGCCATCTGGGTG
SSR
TCTCTGTAT(CA)nCGCACGCAC
GG (SEQ ID NO: 52)
(SEQ ID NO: 53)
(SEQ ID NO: 54)
PULGE1
BACINRA370
GCGTTGCAGTGGCTCTGG
GACACGGCCGCATGAATGTGC
SSR
ACCCCAACA(TA)nATTATGGTA
CG (SEQ ID NO: 55)
(SEQ ID NO: 56)
(SEQ ID NO: 57)
TH(I13A)
AY044828
GCCCGTCTACTTCGTGTCT
ATCTCTGCCTTCATCGCACCC
V
AGGATCCAGCC(A/T)GCAGCCCCG
GAG (SEQ ID NO: 58)
CC (SEQ ID NO: 59)
(SEQ ID NO: 60)
ID
TCACAACCCCC(C)TCCCACAGC
(SEQ ID NOS: 61 and 62)
T
CTGCGGAGGGG(A/G)GACCTGCAG
(SEQ ID NO: 63)
TH(I13B)
AY044828
GCTGCGGACCCCACCGTC
AGACTTCACCCCTAAAAGCCT
ID
GCCAGGT(CAAGGCCAGGT)CGAGGCC
AC (SEQ ID NO: 64)
GG (SEQ ID NO: 65)
(SEQ ID NOS: 66 and 67)
INS(5′)
AY044828
AGCAGGCTGCTGTGCTGGG
AGCCCAGACCCAGCTGACGG
T1
GGCGCTTATGG(G/A)GCCGGGAGC
(SEQ ID NO: 68)
(SEQ ID NO: 69)
(SEQ ID NO: 70)
V
CAAGCCCGG(G/T)CGGTTTGGCCT
(SEQ ID NO: 71)
T2
CTAATGACCTC(A/G)AGGCCCCCA
(SEQ ID NO: 72)
INS(I1, E2, I2)
AY044828
TGATGACCCACGGAGATGA
GCAGTAGTTCTCCAGCTGGTAG
T1
GGGACCAGCTG(C/T)GTTCCCAGG
TCC (SEQ ID NO: 73)
AGGGAA (SEQ ID NO: 74)
(SEQ ID NO: 75)
V
GCCCTGCTGGC(C/G)CTCTGGGCG
(SEQ ID NO: 76)
T2
CTCCCACGCCC(C/T)GGTCCCGCT
(SEQ ID NO: 77)
INS(3′)
AY044828
GCTCTCGGCCACATCGGCT
GGCGCCCAGCTCTAGGCCCGGC
T
GGGCTGGCTGC(G/A)GTCTGGGAG
GC (SEQ ID NO: 78)
(SEQ ID NO: 79)
(SEQ ID NO: 80)
IGF2(E3)
AY044828
CCCCTGAACTTGAGGACGA
CGCTGTGGGCTGGGTGGGCTG
T
GCTGCCCCCCA(A/G)CCTGAGCTG
GCAGCC (SEQ ID NO: 81)
CC (SEQ ID NO: 82)
(SEQ ID NO: 83)
IGF2(E5)
AY044828
CTTGCCTCCAACTCCCTC
AGTGAACGTGAAACGGGGGG
SSR
CTCTCGCTGTC(CT)nCGCCCTCTCTT
CC (SEQ ID NO: 84)
(SEQ ID NO: 85)
(SEQ ID NO: 86)
IGF2(I8)
AY044828
TGCGCCACCCCCGCCAAGT
GCTTCCAGGTGTCATAGCGGA
V
AGCCGGCTCCT(G/C)GGCTTCAAG
CC (SEQ ID NO: 87)
AG (SEQ ID NO: 88)
(SEQ ID NO: 89)
T
AGAGGTTGTTG(C/T)TCTGGGACA
(SEQ ID NO: 90)
SWC9
AY044828
AAGCACCTGTACCCACACG
GGCTCAGGGATCCCACAG
SSR
(CA)n
(SEQ ID NO: 91)
(SEQ ID NO: 92)
IG(IGF2-H19)
AY044828
CACCGCCAGGTCCTGTCGA
GGACCCTGGGGGCTGTGG
T
CGGCCTGTGGC(A/G)GGGAAGCTG
GG (SEQ ID NO: 93)
(SEQ ID NO: 94)
(SEQ ID NO: 95)
H19(??)
AY044828
ACGGTCCCGGGTCAGCAGG
CAGAGCAAGTGGGCACCCAG
T1
CGCGGGTTTGG(C/T)CAGCGGCAG
(SEQ ID NO: 96)
(SEQ ID NO: 97)
(SEQ ID NO: 98)
T2
CACAGAGGACA(C/T)GGCCGCTTC
(SEQ ID NO: 99)
T3
TCCTGGGGGCC(C/T)GCGGCTCGT
(SEQ ID NO: 100)
IG(H19-RL23mrp)A
AY044828
GAGCACAGCCAAAGAACGG
CTTCACCCACGGACATGGCCGC
T
CACCCAGGCTG(C/T)GCCCTGCGT
CCG (SEQ ID NO: 101)
(SEQ ID NO: 102)
(SEQ ID NO: 103)
IG(H19-RL23mrp)B
AY044828
CGGGGGCACTGGGGGTCC
CCGAGACCCTCCTCAAGTCC
T
GTTCGCCCTCC(A/G)CTCTCAGCA
(SEQ ID NO: 104)
(SEQ ID NO: 105)
(SEQ ID NO: 106)
IG(H19-RL23mrp)C
AY044828
TGAGCTGCTGAGCCCACA
CAAGGGAAAGGTGTGCCGACC
T
GGCCGGGCGCT(C/T)CGCCTTCCC
GG (SEQ ID NO: 107)
(SEQ ID NO: 108)
(SEQ ID NO: 109)
IG(H19-RL23mrp)D
AY044828
AGGCAGAGGGCAGAGAGG
CTCCAGCCCCACACTCTGC
T
GCGTCCAGCGC(C/T)GAATCAGGC
GG (SEQ ID NO: 110)
(SEQ ID NO: 111)
(SEQ ID NO: 112)
1 I = intron; E = exon.
2 DSP: type of DNA sequence polymorphism: T = transition, V = transversion, ID = insertion/deletion, SSR = simple sequence repeat.
TABLE 2
Definition of the multisite haplotypes corresponding to the
different markers shown in FIGS. 2 and 3.
STS
MH1
MH2
MH3
MH4
MH5
TSSC5(I1)
T-T
C-C
KVLQT1(I12)
C-C-C-G-C-C
C-T-T-A-T-C
T-C-C-A-T-T
KVLQT1(I11)
T-C-G-C-T-T-G-T
G-T-A-T-C-C-A-T
G-C-G-C-C-C-G-G
389B2T7
C-G-C
T-A-A
TH1 + TH2
T-C-G-
A-(-)-A-(-)
A-C-G-
(CAAGGCCAGGT)
(CAAGGCCAGGT)
(SEQ ID NO: 113)
(SEQ ID NO: 114)
INS(5′) +
G-G-A-C-C-C-G
A-T-G-T-G-T-A
G-G-G-T-G-C-G
IN2(I1, E2, I2) +
INS(3′)
IGF2(E3) +
G-2-G-T
A-2-C-C
A-1-G-T
A-2-G-T
G-2-G-T
IGF2(E5) +
IGF2(I8)
H19
C-C-T
C-C-C
C-T-C
T-T-C
IG(H19-
C-A-T-T
T-G-C-C
RL23MRP)A, B, C, D
TABLE 3
Distribution of genotypes at the Quantitative Trait Nucleotide
IGF2-intron3-nt3072G→A among pig populations strongly selected
(+) or not strongly selected (−) for lean growth.
Genotype
Breed
Lean
G/G
G/A
A/A
Total
European Wild Boar
−
5
0
0
5
European Wild Boar - Uppsala a
−
2
0
0
2
Japanese Wild Boar
−
5
0
0
5
Meishan - Roslin b
−
11
0
0
11
Large White - Uppsala a
+
0
1
7
8
Large White - Roslin b
+
6
1
0
7
Large White - Liège c
+
7
0
0
7
Swedish Large White d
+
0
0
5
5
Swedish Hampshire d
+
0
0
6
6
Swedish Landrace d
+
0
0
5
5
Piétrain - Liège c
+
0
1
6
7
Duroc
+
0
0
1
1
Total
45
3
30
78
a Founder animals in a Wild Boar × Large White intercross (2).
b Founder animals in a Large White × Meishan intercross (16).
c Founder animals in a Piétrain × Large White intercross (1).
d Breeding boars that have been tested for QTL segregation in a previous study (8). The lack of evidence for QTL segregation shows that they can all be considered homozygous at the IGF2 locus.
TABLE 4
Analysis of variance of teat number counted in piglets
of two commercial lines (n = 4477).
Effect
P-value
Contrast
Estimate(s.e)
Genotype of sire
<0.001
QQ-qq
−0.28 (0.05)
Genetic line
0.081
Qq-qq
−0.22 (0.03)
Sex
0.043
M-F
−0.05 (0.03)
TABLE 5
Descriptive statistics of teat number counted in piglets of
two commercial lines (n = 4477) descending from sires
of 3 different genotypes with respect to the mutation.
Average
N
N descending
teat
Genotype
sires
piglets
number
Stdev
A
QQ
2
144
14.51
0.76
Qq
5
1720
14.53
0.82
qq
3
735
14.74
0.86
B
QQ
2
277
14.41
1.00
Qq
7
1054
14.48
0.81
qq
3
547
14.73
0.93
TABLE 6
Allele frequencies for the IGF2-intron3 G3072A
mutation in sows of dam lines (Number of sows
within genotypes is presented in parenthesis)
Line
AA
GA
GG
A
0.04 (4)
0.28 (25)
0.68 (61)
B
0.30 (42)
0.37 (52)
0.33 (46)
C
0.80 (259)
0.19 (62)
0.01 (4)
TABLE 7
Effect of paternal allele inherited from
heterozygous sires on prolificacy
Trait
A
G
Significance*
Number of cycles
240
276
analyzed*
Born alive/litter
10.37 ± 0.18
10.90 ± 0.16
0.0075
Total born/litter
11.04 ± 0.19
11.48 ± 0.17
0.0371
Stillborn/litter
0.63 ± 0.07
0.59 ± 0.06
NS
Weaned/litter
9.11 ± 0.21
9.92 ± 0.16
0.0134
Parity
2.95 ± 0.12
3.54 ± 0.12
0.0035
*Model taking parity and sire into account,
NS = not significant P > 0.05
TABLE 8
Effect of paternal allele inherited from heterozygous sires
on carcass measures at 110 kg live weight (Piglog 105)
Trait
A
G
Significance*
Number of sows
70
64
analyzed*
Back fat 1 (mm)
14.90 ± 0.27
15.08 ± 0.27
NS
Back fat 2 (mm)
13.20 ± 0.29
14.14 ± 0.30
NS
Loin eye (mm)
56.28 ± 0.45
55.72 ± 0.41
NS
% lean meat
57.31 ± 0.26
56.69 ± 0.28
NS
*Model taking sire into account.
NS = not significant P > 0.05
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Flint J. and R. Mott (2001). Finding the molecular basis of quantitative traits: successes and pitfalls. Nature Reviews Genetics 2:437-445. Florini J. R., D. Z. Ewton, and S. A. Coolican (1996). Growth hormone and the insulin-like growth factor system in myogenesis. Endocr. Rev. 17:481-517. Georges M., D. Nielsen, M. Mackinnon, A. Mishra, R. Okimoto, A. T. Pasquino, L. S. Sargeant, A. Sorensen, M. R. Steele, X. Zhao, J. E. Womack and I. Hoeschele (1995). Mapping quantitative trait loci controlling milk production by exploiting progeny testing. Genetics 139:907-920. Grisart B., W. Coppieters, F. Farnir, L. Karim, C. Ford, N. Cambisano, M. Mni, S. Reid, R. Spelman, M. Georges and R. Snell (2002). Positional candidate cloning of a QTL in dairy cattle: Identification of a missense mutation in the bovine DGAT gene with major effect on milk yield and composition. Genome Research 12:222-231. Grobet L., L. J. Royo Martin, D. Poncelet, D. Pirottin, B. Brouwers, J. Riquet, A. Schoeberlein, S. Dunner, F. Menissier, J. Massabanda, R. Fries, R. Hanset, and M. Georges (1997). A deletion in the myostatin gene causes double-muscling in cattle. Nature Genetics 17:71-74. Hanset R., C. Dasnois, S. Scalais, C. Michaux, and L. Grobet (1995). Effets de l'introgression dans le genome Piétrain de l'allèle normal au locus de sensibilité à l'halothane. Genet. Sel. Evol. 27:77-88. Hirooka H., D. J. De Koning, B. Harlizius, J. A. M. Van Arendonk, A. P. Rattink, M. A. M. Groenen, P. Brascamp, and H. Bovenhuis (2001). A whole-genome scan for quantitative trait loci affecting teat number in pigs. J. Anim. Sci. 79:2320-2326. Jeon J. T., O. Carlborg, A. Törnsten, E. Giuffra, V. Amarger, P. Chardon, L. Andersson-Eklund, K. Andersson, I. Hansson, K. Lundström, and L. Andersson (1999). A paternally expressed QTL affecting skeletal and cardiac muscle mass in pigs maps to the IGF2 locus. Nat. Genet. 21:157-158. MacKay T. F. C. (2001). Quantitative Trait Loci in Drosophila. Nature Reviews Genetics 2:11-20. Mauricio R. (2001). Mapping quantitative trait loci in plants: uses and caveats for evolutionary biology. Nature Reviews Genetics 2:370-381. Meuwissen T. H. and M. E. Goddard (2001). Prediction of identity by descent probabilities from marker-haplotypes. Genet. Sel. Evol. 33:605-634. Milan D., J. T. Jeon, C. Looft, V. Amarger, A. Robic, M. Thelander, C. Rogel-Gaillard, S. Paul, N. Iannuccelli, L. Rask, H. Ronne, K. Lundstrom, N. Reinsch, J. Gellin, E. Kalm, P. L. Roy, P. Chardon, and L. Andersson (2000). A mutation in PRKAG3 associated with excess glycogen content in pig skeletal muscle. Science 288:1248-1251. Nezer C., L. Moreau, B. Brouwers, W. Coppieters, J. Detilleux, R. Hanset, L. Karim, A. Kvasz, P. Leroy, and M. Georges (1999). An imprinted QTL with major effect on muscle mass and fat deposition maps to the IGF2 locus in pigs. Nat. Genet. 21:155-156. Nezer C., L. Moreau, D. Wagenaar, and M. Georges (2002). Results of a whole genome scan targeting QTL for growth and carcass characteristics in a Piétrain X Large White intercross. Genetics, Selection, Evolution 34:371-387. Onyango P., W. Miller, J. Lehoczky, C. T. Leung, B. Birren, S. Wheelan, K. Dewar, and A. P. Feinberg (2000). Sequence and Comparative Analysis of the Mouse 1-Megabase Region Orthologous to the Human 11p15 Imprinted Domain. Genome Res. 10: 1697-1710. Reid W. and J. Walter (2001). Genomic imprinting: parental influence on the genome. Nature Reviews Genetics 2:21-32. Riquet J., W. Coppieters, N. Cambisano, J.-J. Arranz, P. Berzi, S. Davis, B. Grisart, F. Farnir, L. Karim, M. Mni, P. Simon, J. Taylor, P. Vanmanshoven, D. Wagenaar, J. E. Womack, and M. Georges (1999). Identity-by-descent fine-mapping of QTL in outbred populations: application to milk production in dairy cattle. Proceedings of the National Academy of Sciences, US 96:9252-9257. Sabeti P. C., D. E. Reich, J. M. Higgins, H. Z. Levine, D. J. Richter, S. F. Schaffner, S. B. Gabriel, J. V. Platko, N. J. Patterson, G. J. McDonald, H. C. Ackerman, S. J. Campbell, D. Altshuler, R. Cooper, D. Kwiatkowski, R. Ward, and E. S. Lander (2002). Detecting recent positive selection in the human genome from haplotype structure. Nature 419:832-837. Terwilliger J. D. (1995). A powerful likelihood method for the analysis of linkage disequilibrium between trait loci and one or more polymorphic marker loci. Am. J. Hum. Genet. 56:777-787.
REFERENCES AND NOTES OF EXAMPLE 2
1. Nezer C. et al., Nature Genet. 21:155-156 (1999).
2. Jeon J.-T. et al., Nature Genet. 21:157-158 (1999).
3. De Koning D. J. et al., Proc. Natl. Acad. Sci. U.S.A. 7947-7950 (2000).
4. Thomsen H., J. C. M. Dekkers, H. K. Lee, and M. Rothschild, paper presented at the 7th World Congress of Genetics Applied to Livestock Production, Montpellier, France 2002.
5. Nezer C. et al., submitted (2003).
6. Florini J. R., D. Z. Ewton, and F. J. Mcwade, Diabetes Rev. 3:73-92 (1995).
7. Amarger V. et al., Mammalian Genome 13:388-398 (2002).
8. Evans G. J. et al., Genetics , in press (2003).
9. QTL genotyping of the Pietrain/Large White, Wild Boar/Large White, and Hampshire/Landrace crosses by marker-assisted segregation analysis was performed as described. (5) Briefly, the likelihood of the pedigree data was computed under two hypothesis: H0, postulating that the corresponding boar was homozygous at the QTL (Q/Q or q/q), and H1 postulating that the boar was heterozygous at the QTL (Q/q). Likelihoods were computed using “% lean meat” as phenotype (as the effect of the QTL was shown to be most pronounced on this trait in previous analyses), and assuming a Q to q allele substitution effect of 3.0%. (1) If the odds in favor of one of the hypotheses were superior or equal to 100:1, the most likely hypothesis was considered to be true. For the Hampshire/Landrace cross, 75 offspring from four boars with identical H254/H205 genotype were merged in a single analysis. The odds in favor of the H0 hypothesis were 103.6:1, indicating that these boars were either Q/Q or q/q.
10. Mackay T. F. C., Nature Rev. Genet. 2:11-21 (2001).
11. Greally J. M., M. E. Guinness, J. Mcgrath, and S. Zemel, Mammalian Genome 8:805-810 (1997).
12. Constancia M. et al., Nature Genet. 26:203-206 (2000).
13. Eden S. et al., EMBO J. 20:3518-3525 (2001).
14. The nucleotide sequence of the conserved footprint surrounding the QTN was analyzed in silico for potential binding sites using the following transcription factor binding site databases (TFSEARCH, worldwideweb.cbrcjp/research/db/TFSEARCH.html; Tess, worldwideweb.cbil.upenn.edu/tess/; Signal Scan, worldwideweb.bimas.dcrt.nih. gov/molbio/signal/; (24) and alibaba2, worldwideweb.gene-regulation.de/). The sequence immediately flanking the QTN did not show any convincing match with known binding sites. However, the entire 94 bp fragment is highly GC-rich and, consequently, several potential binding sites for the Sp- (eight GC-boxes), ZF5 (one consensus binding site), EGR/WT1 (three GSG-elements), and AP2 (three AP-2-boxes) families of transcription factors were identified in sites flanking the QTN. Both activators and repressors are known to competitively or cooperatively interact with such GC-rich motifs. Thus, the high density of potential regulatory elements identified in this fragment is consistent with the obtained EMSA and transfection results.
15. Relative expression of IGF2/HPRT in skeletal muscle from three-week-old pigs was as follows: Q:260.2±70.8 and q:59.6±12.1 (P<0.05, Kruskal-Wallis rank sum test, two sided).
16. Walling G. A. et al., Anim. Genet. 29:415-424 (1998).
17. Giuffra E. et al., Genetics 154:1785-1791 (2000).
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19. Sun F. L., W. L. Dean, G. Kelsey, N. D. Allen, and W. Reik, Nature 389:809-815 (1997).
20. Anderson S. I., N. L. Lopez-Corrales, B. Gorick, and A. L. Archibald, Mammalian Genome 11:811-814 (2000).
21. Nickerson D., V. O. Tobe, and S. L. Taylor, Nucleic Acids Res. 25:2745-2751 (1997).
22. Andrews N. C., and D. V. Faller, Nucleic Acids Res. 19:2499 (1991).
23. Engemann S., O. El-Maarri, P. Hajkova, J. Oswald, and J. Walter, in Methods in Molecular Biology , vol 181: Genomic imprinting: Methods and Protocols A. Ward, Ed. (Humana Press Inc., Totowa, N.J., 2002).
24. Prestridge D. S., Comput. Appl. Biosci. 7:203-206 (1991).
25. Kashuk C., S. Sengupta, E. Eichler, and A. Chakravarti, Genome Res. 12:333-338 (2002).
26. Kumar S., K. Tamura, I B. Jakobsen, and M. Nei, Bioinformatics 17:1244-1245 (2001). | The invention relates to methods to select animals, such as mammals, particularly domestic animals, such as breeding animals or animals destined for slaughter, for having desired genotypic or potential phenotypic properties, in particular, related to muscle mass and/or fat deposition lean meat, lean back fat, sow prolificacy and/or sow longevity. Provided is a method for selecting an animal for having desired genotypic or potential phenotypic properties comprising testing the animal, a parent of the animal or its progeny for the presence of a nucleic acid modification affecting the activity of an evolutionary conserved CpG island, located in intron 3 of an IGF2 gene and/or for the presence of a nucleic acid modification affecting binding of a nuclear factor to an IGF2 gene. | 2 |
FIELD OF THE INVENTION
The present invention relates in general to power management systems for turbine engines and in particular to a propeller governor control for turboprop engines.
BACKGROUND OF THE INVENTION
Historically, turboprop engines have been controlled via two levers in the cockpit. A speed lever adjusts engine power-turbine speed and a power lever controls engine power. The pilot would adjust the speed lever to obtain the desired engine speed setting. Then, the pilot "closes the loop" on torque by watching a gauge and moving the power lever angle to the desired torque level. Engine power-turbine speed increases until the desired speed is reached. As the power lever is advanced further, engine speed remains constant, but engine torque would be further increased.
Propeller shaft speed is controlled by a power-turbine speed governor. A torque motor on the governor allows for the adjustment of the propeller shaft speed. The speed lever sets the governor to a desired speed. As the power lever is adjusted, the governor adjusts the pitch of the blades to hold the engine at the desired speed. The governor regulates propeller blade pitch by controlling the pressure of oil supplied to a propeller speed. By increasing the pressure of oil supplied to the propeller dome, blade pitch is reduced; and by decreasing the pressure of oil supplied to the propeller dome, blade pitch is increased.
Among the problems associated with the governor control loops is propeller overshoot. When the engine is commanded to accelerate, much added energy is required to accelerate the propeller to the commanded speed. Once the power turbine reaches the commanded speed, the governor begins to change blade angle. Due to the proportional regulation action of the power turbine speed governor and the inertia of the propeller, however, the engine overshoots its commanded speed.
Therefore, it is an object of the present invention to prevent propeller overshoot.
SUMMARY OF THE INVENTION
Apparatus according to the present invention prevents propeller overshoot by modifying a speed command supplied to a propeller governor. The apparatus comprises delta speed means and modifying means. The delta speed means provides a delta speed signal indicating changes in propeller speed. When actuated by the delta speed means, the actuatable modifying means modifies the speed command such that the propeller governor begins to change blade pitch before the propeller speed reaches the commanded speed. The speed command is modified when the delta speed signal falls outside a steady-state initial condition range.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial view of an aircraft having twin turbo prop engines;
FIG. 2 is a graph of speed set point versus current for a propeller governor;
FIG. 3 is a block diagram of a propeller governor control according to the present invention; and
FIG. 4 is a graph of snap power level movement responses of propeller speed.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, there is shown an aircraft 10 having twin turbo prop engines 12. Each engine 12 has a turbine-type power plant that includes a compressor section (not shown), combustion section (not shown) and a turbine section (not shown). These sections are arranged in serial flow relation. A spinner 14 is connected to the aft end of each engine 12. A plurality of propeller blades 16 are circumferentially disposed about the spinner 14 and extend radially therefrom. Air that enters each engine 12 is compressed in the compressor section. The compressed air is discharged to the combustion section, where the air is mixed with fuel. The mixture is ignited to produce hot expanding gases that turn the turbine section, which, in turn, drives the propeller blades 16. The propeller blades 16 move a mass of cold air to create a thrust. The thrust produced by the propeller blades 16 is varied by changing blade pitch. The pitch is changed by rotating the blades 16 about their longitudinal axes.
In conventional power management systems, engine speed is controlled by a speed lever. However, in applicants' copending application Ser. No. 07/762,322 entitled "POWER MANAGEMENT SYSTEM FOR TURBINE ENGINES", speed is set by a plurality of flight mode buttons that correspond to various flight modes (e.g., takeoff, climb, cruise). In response to the flight mode buttons, this power management system issues speed commands to the propeller governor, which closes a speed loop to maintain engine speed at the commanded speed. Application Ser. No. 07/762,322, filed concurrently herewith, and now issued as U.S. Pat. No. 5,315,819, is incorporated herein by reference. For the purposes of this specification, however, a power management system refers to any system that issues speed commands tothe propeller governor. Such systems include, but are not limited to, conventional power management systems and applicants' power management system of Ser. No. 07/762,322.
The power management system provides a current representing a speed commandto a speed setpoint actuator (i.e., the torque motor) on the propeller governor. The speed command sets a target speed, which is expressed as a percentage of maximum rated engine speed. See, for example, the graph of FIG. 2, which shows speed set point versus input current. The speed setpoint actuator controls the position of a flyweight to establish a target speed for the propeller. The flyweight controls a spool valve, which regulates the flow of oil to the propeller dome.
Referring now to FIG. 3, the propeller governor control logic receives a speed command NPSTS from a power management system (not shown). The speed command NPSTS is supplied to a rate limiter 18, which limits the rate of change in the commanded speed to a value PGMRL allowing for a smooth transition in propeller speeds when the pilot changes speeds. The output of the rate limiter 18 provides the flight speed command NPSFLT.
The propeller governor logic includes a limited-authority trim integrator which functions as a calibration compensation block 20. There can be smallerrors in the calibration of a propeller governor on the order of 0.25%. These small errors are compensated for with adjusting the flight speed command NPSFLT by a compensation signal NPTRM in order to force the propeller governor to operate at the speed set by the flight speed commandNPSFLT. A first subtracter 22 takes the difference of the flight speed command NPSFLT and a signal indicating measured propeller speed NP. The propeller speed NP is measured by such well known means as speed monopoles. An output of the first subtracter 22 provides a difference signal DELTNP. One output of the first subtracter 22 is coupled to pole 0 of a first switch 24, and another output is coupled to an input of a firstblock 26. The first block 26 compares the difference signal DELTNP to a limit MXDNP, such as two percent. Below this limit, the difference signal DELTNP is considered small; therefore, the first block 26 issues a signal MXDNPL that causes the first switch 24 to switch to pole 0, whereby the difference signal DELTNP is supplied to a limited integrator 28. In the limited integrator 28, the difference signal DELTNP is integrated over time, multiplied by a gain KPROP and limited to a value NPTRMN such as twopercent. The output of the limited integrator 28 provides the steady-state component to compensate for propeller governor error, thus ensuring zero propeller speed error. This steady-state component is the calibration error. Thus, the limited integrator 28 behaves as a speed-error trim integrator. An output of the limited integrator 28 provides the compensation signal NPTRM, which is added to the flight speed command NPSFLT by an adder 30. The output of the adder 30 provides an adjusted speed command NPSCMD. Thus, the calibration compensation block 20 adjusts the flight speed command NPSFLT to compensate for small calibration errorsthat cause a difference between actual speed NP and the speed command NPSFLT.
The calibration compensation block 20 does not adjust the flight speed command NPSFLT for large transients. When the difference signal DELTNP exceeds the limit MXDNP, the output signal MXDNPL causes the first switch 24 to switch to pole 1. Pole 1 of the first switch 24 is coupled to an output of a first multiplier 32, which multiplies the compensation signal NPTRM, provided by the limited integrator 28, by a constant -1.0. Thus, when the first switch 24 is switched to pole 1, the signal -NPTRM is fed back into the input of the limited integrator 28. As a result, the output signal from the limited integrator 28 is driven to zero. Thus, for a largetransient, the compensation signal NPTRM is set to zero.
The propeller governor control also includes a rate anticipation block 34, which prevents the engine 12 from overshooting its speed commanded by the adjusted speed command NPSCMD. The rate anticipation block 34 provides a rate anticipation signal NPSRC that causes the set point actuator of the propeller governor to be set to a "false" set point, i.e., premature set point. The rate anticipation signal NPSRC is subtracted from the adjusted speed command NPSCMD by a second subtracter 36. An output of the second subtracter 36 supplies the propeller setpoint speed command NPSETC to the speed set point actuator of the propeller governor. Once the measured propeller speed NP reaches the false set point, the propeller governor begins to change blade angle. Although the propeller speed overshoots the false set point, the overshoot is still below the speed commanded by the adjusted speed command NPSCMD. As the change in propeller speed is slowed,the rate anticipation signal NPRSC goes to zero, and the setpoint speed command NPSETC approached the adjusted speed command NPSCMD. Thus, the propeller is eased into the speed commanded by the adjusted speed command NPSCMD.
The rate anticipation signal NPSRC is calculated as a weighting factor KNPDA times the derivative NPWS of propeller speed with respect to time. The derivative NPWS is calculated from measured propeller speed NP by a differentiator 38. As the rate of change of propeller speed approaches zero, the derivative NPWS approaches zero. When measured propeller speed NP is greater than thirty percent, the weighting factor KNDPA is set equalto the signal KNDP. The signal KNPD is an apriori value that indicates the amount of the derivative NPWS that is allowed to affect propeller speed setpoint command NPSETC. For example, the signal KNPD can have the value of 0.5. Thus, when the measured speed NP is greater than thirty percent, asecond block 40 provides an output that causes a second switch 42 to selectthe signal KNPD from a first memory location 44. A second multiplier 46 takes the product of the derivative NPWS and the signal KNPD. The product is limited by an authority limiter 48 to a value NPDLM, such as ±10 percent. An output of the authority limiter 48 provides the rate anticipation signal NPSRC. Thus, decreasing propeller speed drives the derivative NPWS to zero which, in turn, drives the rate anticipation signal NPSRC to zero.
When propeller speeds NP are below thirty percent, the rate anticipation block 34 is disabled. At such speeds, rate anticipation is unnecessary. For example, overshoot is not a concern during startup. When propeller speeds NP are below thirty percent, the second block 40 provides an outputthat causes the second switch 42 to select the value 0.0 from a second memory location 50. Thus, the second multiplier 46 multiplies the derivative NPWS by the value zero. As a result, the rate anticipation signal NPSRC is zero, and the setpoint speed command NPSETC is equal to the adjusted speed command NPSCMD.
When employed in a microprocessor-based power management system, the propeller governor control is most conveniently realized through software.Thus, the propeller governor control logic is programmed into the microprocessor. The step of programming can be readily accomplished by a person skilled in the art.
Alternatively, the propeller governor control can be realized by hardware. Adders, subtracters, multipliers, limiters, comparators, differentiators and filters (i.e., integrators) are well known to those skilled in the art.
Referring now to FIG. 4, the response of propeller speed is plotted over time for a snap acceleration from flight idle to 70% torque. Measured propeller speed NP is indicated by curve A. Propeller setpoint speed NPSETC is indicated by curve B. Speeds NP and NPSETC are given as a percentage of maximum rated engine speed. Results for this plot were derived from engine tests and flight tests of a TPF351-20 free turbine engine, manufactured by Garrett Engine Division of Allied-Signal, Inc., the assignee of the present invention.
It will be understood that the embodiment described herein is merely exemplary and that a person skilled in the art may make many variations and modifications without departing from the spirit and scope of the invention. All such modifications are intended to be included within the scope of the invention as defined in the appended claims. | To prevent propeller overshoot, a propeller governor control generates a signal which modifies a speed command issued to a propeller governor. The signal causes the propeller governor to change blade pitch before the propeller reaches its commanded speed. The propeller governor control also compensates for small calibration errors in the propeller governor. | 1 |
BACKGROUND
[0001] The present invention relates to industrial vehicles, and more particularly to devices for controlling the transmission of such vehicles.
[0002] Many industrial vehicles include a tractor which is mobilized either by separate wheels or by tracks driven by wheel trains. In both cases, the wheels of the tractor are typically rotated by a drive system that includes one or more motors, each having a shaft connected to driven wheels by means of a transmission mechanism. Generally, such transmission mechanisms are adjustable between at least two operating conditions, for example, a “high speed/low torque”condition and a “low speed/high torque” condition, and may operate at three or more states to inversely vary the torque and speed.
[0003] In many industrial vehicles, the transmission mechanisms are gear trains that are adjustable between different operating states or “gear ratios” by means of one or more actuators, for example, hydraulic clutches. The clutches function to alternatively engage with and disengage from certain gear train components in order to change gear ratios, and thus vary the speed and torque applied to the driven wheels. However, due to the mass of these vehicles, changing between gear ratios when the vehicle is moving above a given speed may damage the transmissions. As such, the operating manuals generally instruct the operator to stop the vehicle prior to changing of the gear ratio, which instruction may or may not be followed.
SUMMARY
[0004] The present invention provides a system for controlling gear shifting of an industrial vehicle having a transmission operable between at least two gear ratios by actuation of a transmission actuator in response to a gear ratio command. The system generally comprises a sensor configured to monitor one or more vehicle parameters and a controller associated with the sensor, the gear ratio command and the transmission actuator. The controller is configured to prevent actuation of the transmission actuator unless one or more vehicle parameters is in a predetermined condition. In a first embodiment, the sensor monitors the speed of the vehicle and actuation of the transmission actuator is prevented unless the vehicle speed is less than or equal to a limit value. In a second preferred embodiment, the sensor monitors whether the vehicle drive system is in neutral or in drive and actuation of the transmission actuator is prevented unless the drive system is in neutral. By preventing actuation of the transmission actuator, the controller helps reduce the risk of damage to the transmission.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] [0005]FIG. 1 is an isometric view of an illustrative industrial vehicle.
[0006] [0006]FIG. 2 is a bottom plan view illustrating the drive system of the vehicle of FIG. 1.
[0007] [0007]FIG. 3 is a system diagram of a first embodiment of the transmission control system of the present invention.
[0008] [0008]FIG. 4 is a flow diagram of a first control sequence of the controller of the first embodiment.
[0009] [0009]FIG. 5 is a flow diagram of a second control sequence of the controller of the first embodiment.
[0010] [0010]FIG. 6 is a system diagram of a second embodiment of the transmission control system of the present invention.
[0011] [0011]FIG. 7 is a flow diagram of a first control sequence of the controller of the second embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] The preferred embodiments of the present invention will be described with reference to the drawing figures with like numerals representing like elements throughout. Certain terminology, for example, “right”, “left”, “forward” and “reverse”, is used in the following description for clarity of relational description only and is not intended to be limiting.
[0013] Referring to FIGS. 1 and 2, an illustrative industrial vehicle, a paver 10 , is shown. The illustrated paver 10 includes a tractor 12 , mounted on opposed drive tracks 14 , and various conveyors 36 and augers 38 . Power is provided by an engine 16 and delivered through a PTO clutch 18 and drive shaft 20 to a pump drive box 22 . Traction drive power is hydrostatically transmitted from independent left-hand and right-hand traction drive pumps 24 a , 24 b to left-hand and right-hand drive units 26 a , 26 b located inside the respective drive track assemblies 14 . In vehicles having separate wheels and a steering wheel, as opposed to independent drive tracks, a single drive unit may be used. Each drive unit 26 a , 26 b includes a motor 28 coupled to a planetary transmission hub 30 via an actuator 31 , in this case, a solenoid valve controlled hydraulic clutch. Mechanical levers 29 a , 29 b control the traction drive pumps 24 a , 24 b to operate the drive motors 28 between neutral and forward and reverse drive. The left and right-hand actuators 31 are controlled by an operator input device 32 on the operator's console 34 . The input device 32 provides an electrical signal indicative of the desired gear ratio. Preferably, a single device is utilized to send a common signal to both actuators 31 such that both transmissions 30 maintain the same gear ratio. While the illustrated vehicle is described with specific control levers, transmissions and actuators, other devices may also be used.
[0014] In the present invention, a transmission control system 100 is positioned in the path of the gear input signal between the input device 32 and the actuators 31 . Preferably the control system 100 is self-contained such that it can be manufactured within a vehicle electrical system or spliced into the electrical system of an existing vehicle. Additionally, the self-contained system 100 can easily be removed from the electrical system, for example, for maintenance or replacement.
[0015] Referring to FIGS. 3 and 4, a first embodiment of the control system 100 is illustrated. In this embodiment, the control system 100 includes a controller 110 which receives input from the gear inputs 32 and from a vehicle speed sensor 120 , for example, the vehicle's speedometer sensor. Based on the information received from the gear and speed inputs 32 , 120 , the controller 110 determines the appropriate gear signal to be sent to the transmission actuators 31 which in turn control the gear ratios of the transmissions 30 .
[0016] The controller 110 determines the appropriate gear signal in accordance with the flow diagram illustrated in FIG. 4. The controller 110 continuously monitors the gear input and determines if it is equivalent to the current gear. If it is, the controller 110 maintains the current gear signal being sent to the actuators 31 . As such, if the gear input is not changed, the controller 110 maintains a continuous loop of checking the input and maintaining the gear signal at the current value. If, on the other hand, the gear input is changed, the controller 110 then determines, based on the vehicle speed input 120 , if the vehicle speed is above a limit value. It is preferred that the limit value equal zero, however, for different vehicles and different transmission arrangements, it may be acceptable to change gears at speeds greater than zero. For example, with the illustrated paver, it may be acceptable to change gears when the vehicle speed is 10 feet-per-minute or less. The limit speed can be set to meet the criteria of a given application.
[0017] If the vehicle speed is less than or equal to the limit value, the controller 110 sends the new gear input to the actuators 31 which in turn change the transmission gear ratios. If the vehicle speed is greater than the limit value, the controller 110 maintains the current gear signal being sent to the actuators 31 , i.e., the controller 110 prevents a gear change while the vehicle speed is greater than the limit value. The controller 110 then waits a given amount of time, for example, 5 seconds, and again determines if the vehicle speed is greater than the limit value and repeats the control sequence as described above. It is intended that the operator will recognize that the gear ratio has not changed, and thereby will be alerted to slow the vehicle to a speed at or below the limit value. The control system 100 may also include an indicator (not shown), for example, a light or sound, which alerts the operator that the gear change is being prevented due to vehicle speed. Once the vehicle speed has been slowed to or below the limit speed, the controller 110 sends the new gear input to the actuators 31 which in turn change the transmission gear ratios as described above.
[0018] Referring to FIG. 5, an alternate control sequence is illustrated. In this sequence, if the speed is greater than the limit value, the controller 110 automatically places the vehicle drive into neutral to assist in slowing the vehicle and alerting the operator. If the vehicle has an electrically control drive mechanism, the controller 110 is configured to provide the drive mechanism with a neutral signal. If the drive mechanism is a mechanical system, as in the illustrated paver 10 , the vehicle is provided with a mechanical shift override, an electro-mechanical device configured to receive a signal from the controller 110 and mechanically override the vehicle mechanical system to place the drive in neutral. After the drive is in neutral, the controller 110 will wait a predetermined amount of time and repeat the control sequence described above.
[0019] Referring to FIGS. 6 and 7, a second embodiment of the control system 200 is illustrated. The controller 110 receives input from the gear input 32 and a vehicle drive input 220 . The vehicle drive input 220 is configured to signal the controller 110 whether the respective traction drive motors 28 are in neutral, or alternatively, are in forward or reverse drive. In the preferred embodiment, the specific drive direction is not material, only the distinction between neutral and a drive condition. Based on the information received from the gear and vehicle drive inputs 32 , 220 , the controller 110 determines the appropriate gear signal to be sent to the transmission actuators 31 which in turn control the gear ratios of the transmissions 30 .
[0020] The controller 110 determines the appropriate gear signal in accordance with the flow diagram illustrated in FIG. 7. The controller 110 continuously monitors whether the drive motors 28 are in neutral. In the preferred embodiment, the drive signals for both motors are connected in series such that as either of the traction levers 29 a , 29 b is moved off of neutral, either forward or reverse, the signal from the vehicle drive input 220 drops from operating voltage, approximately 12 volts DC, to 0 volts DC. When the signal is 12 volts DC, the controller 110 recognizes both of the drive motors 28 are in neutral.
[0021] If the drive motors 28 are not in neutral, the controller 110 maintains the current gear signal being sent to the actuators 31 and disregards any new gear input signals, i.e., the controller 110 prevents a gear change when the motors are not in neutral. It is intended that the operator will recognize that the gear ratio has not changed, and will thereby be alerted to shift the vehicle drives to neutral. The control system 200 may also include an indicator (not shown), for example, a light or sound, which alerts the operator that the gear change is being prevented due to the vehicle drive. Once the vehicle drives have been placed in neutral, the controller 110 proceeds with the control sequence as described below.
[0022] Once a neutral signal is detected, the controller 110 determines if the transmissions 30 are currently operating in a “low”gear ratio, i.e., low speed, high torque. If the transmissions 30 are in a low gear ratio, the controller 110 sends a signal to apply the vehicle's parking brake. In the preferred embodiment, the vehicle parking brake is a function of the transmissions 30 , that is, a brake signal causes the actuators 31 to produce a gear ratio which stops the drive track drive units 26 a , 26 b . However, the parking brake may also be configured to be independent of the transmission assembly. After the parking brake is applied, the controller 110 determines if a new gear ratio is selected by determining if the gear ratio input is equal to the current low gear operating condition or to a high gear ratio signal. If the gear ratio input signal is maintained at low while the vehicle is in neutral, the signal is not changed. If the gear ratio input signal is changed to high while the vehicle is in neutral, the controller 110 sends the new gear input to the actuators 31 which in turn change the transmission gear ratios. In the preferred embodiment in which the park brake is associated with the transmissions 30 , the controller 110 awaits shifting of the drive from neutral and then, simultaneously therewith, sends the new gear ratio signal to the actuators 31 , thereby avoiding premature deactivation of the parking brake. In embodiments wherein the parking brake is independent of the transmission signal, the signal can be sent immediately since it will not interfere with the parking brake.
[0023] If a neutral signal is received when the vehicle transmission is in a high gear, i.e. high speed, low torque, the controller 110 checks the gear input signal. If the gear input signal is a high gear signal, i.e., no change in gear, the controller 110 maintains the current gear signal. If the gear input signal is a low gear signal, i.e., a gear shift, the controller 110 waits a given amount of time, for example, 2 seconds, and then applies the parking brake. The delay helps prevent the paver from lurching to a halt from a high speed. After application of the parking brake, the new gear signal will be transmitted. Again, if the parking brake is associated with the transmissions, the controller 110 awaits a shifting from neutral before sending the new signal.
[0024] The automatic application of the parking brake is preferably included to prevent undesired rolling of the vehicle during working operation, for example, when the paver is paving. In the illustrated control sequence, the brake is not applied when the gear ratio is maintained in high gear since this is typically a travel gear condition as opposed to a working gear condition. If desired, the controller 110 can be configured to apply the brake in all conditions. Additionally, some vehicles have transmission ratios which are sufficient to independently prevent vehicle rolling when the motors are in neutral. In such cases, each of the “apply brake” steps of the control sequence can be eliminated.
[0025] Another feature of many industrial vehicles is a destroking of the traction pump when the vehicle brake is applied. This feature is intended to prevent an operator from trying to “drive through” the braking condition. The controller 110 of the present invention can be configured to override this destroking feature when the brake is automatically applied. Since the brake is only automatically applied when the drive motors are in neutral, the potential for “drive through” is eliminated, thereby eliminating the need for destroking. To override the destroke feature, the controller 110 sends a signal overriding the destroke signal to the mechanism controlling destroking of the pumps. Since the pumps are not destroked, they will not have to “spool up” when the drives are moved from neutral, but will instead by ready for immediate operation. This prevents the vehicle from coasting forward or backwards on grades while the pumps spool up.
[0026] It will be appreciated by those skilled in the art that changes can be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as generally and illustratively described herein. | A system for controlling gear shifting of an industrial vehicle having a transmission operable between at least two gear ratios by actuation of a transmission actuator. The system generally comprises a sensor configured to monitor one or more vehicle parameters and a controller associated with the sensor and the transmission actuator. The controller is configured to prevent actuation of the transmission actuator unless one or more vehicle parameters is in a predetermined condition. | 1 |
FIELD OF THE INVENTION
The present invention generally relates to a flexible printed circuit board, and more particularly relates to a thermal bonding structure and manufacture process of a flexible printed circuit board that can improve the issues of bonding burns and material quality.
BACKGROUND OF THE INVENTION
As our living standard is improving gradually, various electronic consumer products are introduced to meet extensive consumer requirements, and thus promoting the prosperity of various industries directly and driving the growth of related sub-industries indirectly. To further meet the consumer requirements and trends for various functions, portability, operability and appearance, in hope of improving consumer's willingness to buy and brand loyalty, various electronic consumer products tend to be designed thinner and lighter. For example, the market share of color mobile phones with a photographic function and other combined functions grows drastically, and the demand of color LCD panels and camera modules for mobile phones rises accordingly. Color LCD panel industry is divided into the area of color super twisted nematic (CSTN) LCDs and thin-film transistor (TFT) LCDs, and the key components including light emitting diodes (LEDs) and flexible printed circuit (FPC) boards also grow with the high demand for flexibility, 3-D circuit layout and light weight of a miniaturized foldable design of mobile phones. The estimated quantity of flexible printed circuit boards used in a color mobile phone is increased from 3˜4 pieces to 6˜7 pieces, and the design of flexible printed circuit boards tends to follow a high-end small circuit specification. A flexible printed circuit board is made by raw materials including a flexible insulating substrate material and a circuit conductor material (generally copper clad), and the raw materials are divided into resins, copper clads, adhesives, coverlays, and flexible copper cladded laminates (FCCL). Since polyimide (PI) has good expansibility and heat resistance, therefore PI is generally used as a resin material and serves as a middle layer and a substrate in the manufacture of flexible copper substrates and also as a coverlay film.
PI manufacturers can produce different PI films from different PI monomers according to different technologies in three main aspects: formula, manufacture process and processing method, and thus different manufacturers achieve different applications and performance of the materials. Further, the flexible copper substrate is divided into two main types: an adhesive three-layer structure and an adhesiveless two-layer structure, and both adopt different manufacture processes, methods and applications, and thus the properties of the materials are different. In general, the adhesive three-layer structure is usually applied to the production of a large number of flexible printed circuit board products and the adhesiveless two-layer structure is usually applied to the manufacture of high-end flexible printed circuit boards, such as the rigid and flexible printed circuit boards and some of the multi-layer boards. It is believed that the adhesiveless two-layer structure will take over some of the adhesive three-layer flexible copper cladded laminates used for the flexible printed circuit boards with high resolution and good dimensional stability.
Referring to FIG. 1 , a schematic view of the relation between the raw materials and the finished goods of a prior art flexible printed circuit board is illustrated. In the manufacture of the flexible printed circuit board 150 , an insulating substrate material 100 and a circuit conductor material 110 are used to produce an adhesiveless two-layer flexible copper cladded laminate 130 first, and then a coverlay, a stiffener, and an anti-static layer are used to produce the flexible circuit board 150 . On the other hand, an adhesive three-layer flexible copper cladded laminate 140 is made of an insulating substrate material 100 , a circuit conductor material 110 and an adhesive 120 , and a flexible printed circuit 150 is made of such laminate 140 . At present, flexible printed circuit boards are generally used in electronic products, particularly mobile phones and LCDs showing a drastic a growth of using flexible circuit boards in their applications.
Referring to FIG. 2 , a top view of a flexible printed circuit board and a cross-sectional view of a bonding head according to a prior art are illustrated. The flexible printed circuit board 2 comprises a first insulating layer 200 , an adhesive layer 210 , a conductive layer 220 and a second insulating layer; wherein the first insulating layer 200 and the second insulating layer 240 are made of the same material or different materials, and the first insulating layer 200 includes a solder pad area 270 and the second insulating layer 240 includes a bonding area 250 , such that a bonding head 260 is in direct contact with the bonding area 250 for soldering the flexible printed circuit board 2 with another flexible printed circuit board. In actual practices, the boding area 250 is usually situated at a position substantially parallel to the solder pad area 270 , so that heat energy can be conducted from the bonding area 250 to the adhesive layer 210 , conductive layer 220 and solder pad area 270 for bonding. However, it is necessary to increase the temperature of the bonding head 260 for bonding, and the high temperature will burn the first insulating layer 200 and the adjacent adhesive layer 210 black, and thus causing poor bonding quality and appearance of the product, or even deteriorating the materials in the bonding area. For example, a bonding machine sets a temperature for the bonding head for a thermal compression, and the temperature of the bonding head is set to 330° C. for a predetermined time (such as 3 seconds for temperature rise) and then the operating temperature of the bonding machine is set to 470° C. for another predetermined time (such as 3.5 seconds for the bonding), then the solder will be fused to complete the bonding process. However, the first insulating layer 200 and its adjacent adhesive layer 210 will be burned black at the temperature of 470° C., and such phenomenon is particularly severe for lead-free solders because the melting point of lead-free solders is higher than that of lead solders. For example, the melting points of the solders of the Sn—Ag—Cu series and Sn—Cu—Ni series are 227° C. and 217° C. respectively. Compared with the melting point 183° C. of solder of the Sn—Pb series, there is a difference of 34˜44° C. Therefore, it is necessary to increase the temperature of the bonding head 260 for lead-free solders in compliance with the environmental protection and international standard requirements. As a result, the burning effect produced in the bonding area 250 becomes obvious and severe.
Therefore, developing a thermal bonding structure and manufacture process for a flexible printed circuit board to overcome the foregoing shortcomings of the prior arts, improving the burning situation in the bonding area, and further conducting heat energy to the solder so as to lower the bonding temperature and supply less heat energy for saving bonding time and costs are important topics for manufactures and users and demand immediate attentions and feasible solutions. The inventor of the present invention based on years of experience on related research and development of the optoelectronic component industry to invent a thermal bonding structure and manufacture process for flexible printed circuit boards to overcome the foregoing shortcomings.
SUMMARY OF THE INVENTION
Therefore, it is a primary objective of the present invention to provide a thermal bonding structure of a flexible printed circuit board that comprises: a laminated structure and the laminated structure includes a first insulating layer, a first conductive layer, a second insulating layer, a second conductive layer and a third insulating layer in sequence; at least a through hole for passing through the first conductive layer, the second insulating layer and the second conductive layer. The first insulating layer includes a solder pad area for exposing the first conductive layer, and the third includes a bonding area for exposing the second conductive layer, such that the bonding head is in direct contact with the bonding area, and the heat energy can be conducted to the solder pad area through the through hole quickly for bonding.
Another objective of the present invention is to provide a flexible printed circuit board comprising a first area, and the first area includes a laminated structure having a first insulating layer, a first conductive layer, a second insulating layer, a second conductive layer and a third insulating layer arranged in sequence; a second area including a laminated structure coupled to the first area and having a first insulating layer, a first conductive layer, and a second insulating layer arranged in sequence; and a third area including a laminated structure disposed away from the first area and coupled to the second area and having the foregoing first insulating layer, first conductive layer, second insulating layer, second conductive layer and third insulating layer arranged in sequence; and at least one through hole passing through the foregoing first conductive layer, second insulating layer and second conductive layer. The first insulating layer in the third area includes a solder pad area for exposing the first conductive layer and being in contact with the solder, and the third insulating layer includes a bonding area for exposing part of the second conductive layer to define a bonding area, such that the heat energy of the bonding head can be conducted to the solder pad area through the through hole quickly to reduce bonding time and heat supply costs.
A further objective of the present invention is to provide a manufacture process of a flexible printed circuit board that comprises the steps of: providing a laminated structure and the laminated structure is divided into a first area, a second area and a third area, and the second area is disposed between the first area and the third area, and the laminated structure in the first and third areas includes a first insulating layer, a first conductive layer, a second insulating layer, a second conductive layer and a third insulating layer arranged in sequence, and the second area includes a first insulating layer, a first conductive layer, a second insulating layer, and at least one through hole formed in the first area and third area separately and passing through the first conductive layer, the second insulating layer and the second conductive layer; removing a part of the third insulating layer to expose the second conductive layer and define a bonding area; removing a part of the first insulating layer in the third area to expose the first conductive layer and define a solder pad area; and removing a part of the third insulating layer in the third area to expose the second conductive layer and define a bonding area.
Thus, the thermal bonding structure and manufacture process of a flexible printed circuit board in accordance with the present invention has the following advantages. Since the heat consumption at the insulating layer is reduced, therefore the bonding head can achieve the bonding effect with less heat energy and the cost for the bonding process can be lowered. Furthermore, the bonding head is applied to the bonding area, and the through hole is used to conduct heat energy to the solder pad area to accomplish the bonding process, and thus the temperature of the bonding head can be controlled to improve the burning phenomenon caused by the high temperature of the bonding head and occurred at the bonding area, so as to enhance the soldering process, the material quality, and the appearance of the product.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of the relation between the raw materials and the finished goods of a prior art flexible printed circuit board;
FIG. 2 shows a top view of a finished goods of a flexible printed circuit board and a cross-sectional view of a bonding head according to a prior art;
FIG. 3 shows a top view of a thermal bonding structure of a flexible printed circuit board and its corresponding cross-sectional view according to a preferred embodiment of the present invention;
FIG. 4 shows a top view of a flexible printed circuit board and its corresponding cross-sectional view according to a preferred embodiment of the present invention; and
FIG. 5 shows a flow chart of the manufacture process of a flexible printed circuit according to a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
To make it easier for our examiner to understand the objective of the invention, its innovative features and performance, a detailed description and technical characteristics of the present invention are described together with the drawings as follows.
Referring to FIG. 3 , a top view of a thermal bonding structure of a flexible printed circuit board and its corresponding cross-sectional view according to a preferred embodiment of the present invention are illustrated. In the preferred embodiment, a thermal bonding structure 3 of a flexible circuit board comprises: a laminated structure having a first insulating layer 310 , an adhesive layer 320 , a first conductive layer 330 , an adhesive layer 320 , a second insulating layer 340 , an adhesive layer 320 , a second conductive layer 350 , and a third insulating layer 360 ; and at least one through hole 380 passing through each layer between the first conductive layer 330 and the second conductive layer 350 . The first insulating layer 310 includes a solder pad area 390 for exposing the first conductive layer 330 , and the third insulating layer 360 includes a bonding area 365 for exposing the second conductive layer, and the through hole 380 is formed beyond the range of the solder pad area 390 and the bonding area 365 . In other words, there is a gap between the solder pad area 390 and the bonding area 365 . Referring to FIG. 3 for a cross-sectional view of a thermal bonding structure of a flexible printed circuit board according to a preferred embodiment of the present invention, the through hole 380 is formed beyond the range of the solder pad area 390 and the bonding area 365 . It is noteworthy that each conductive layer can be stacked on top of each insulating layer directly as disclosed in another embodiment, since the laminated structure of the thermal bonding structure of the flexible printed circuit board can only have a first insulating layer 310 , a first conductive layer 330 , a second insulating layer 340 , a second conductive layer 350 and a third insulating layer 360 . The through hole 380 of this embodiment includes an electric conductive material on its internal wall, and the materials used for making the first conductive layer 330 and the second conductive layer include a copper clad, and the surface of the second conductive layer 350 of the bonding area 365 further includes a metal layer for protecting the second conductive layer 350 . The metal layer could be single-layer or multiple-layer and made of gold, nickel, tin, other metal, or an alloy of the foregoing metals. In this embodiment, a nickel layer and a gold layer are formed in sequence on the surface of the second conductive layer 350 of the bonding area 365 , and the materials used here are provided for the purpose of describing the present invention and not intended to limit the invention. Further, the quantity and size of the through holes 380 vary with the speed and time of the heat conduction, and thus the positions of the through holes and the bonding area described in this embodiment are provided for example only, and not limited to the same number and size of the through holes 380 as depicted in FIG. 3 .
A lithographic etching is adopted to remove a part of the third insulating layer 360 to define a bonding area 365 , so that heat energy can be conducted directly and quickly from the second conductive layer 350 to the first conductive layer 330 and fuse a solder such as a solder paste in the solder pad area 390 . With the same conditions as the prior art, a solder can be fused to complete a bonding process with a lower temperature, if the temperature of the bonding machine is set to 330° C. for a predetermined time (such as 3 seconds for temperature rise) and the operating temperature of the bonding machine to 400° C.,and the bonding head 370 is operated for a bonding time (such as 3.5 seconds), and thus improving or avoiding the burning phenomenon at the bonding area 365 and the third insulating layer 360 .
Referring to FIG. 4 , a top view of a flexible printed circuit board and its corresponding cross-sectional view according to a preferred embodiment of the present invention are illustrated. In this embodiment, the flexible printed circuit board 4 is divided into a first area 410 , a second area 430 coupled to the foregoing first area 410 and a third area 450 disposed away from the first area 410 and coupled to the second area 430 . The flexible printed circuit board 4 comprises a laminated structure, and the first area 410 (which is a connecting area for components such as the light emitting diodes) and the third area 420 include a first insulating layer 411 , a first conductive layer 412 , a second insulating layer 413 , a second conductive layer 414 and a third insulating layer 415 arranged in sequence, and the second area 430 includes a first insulating layer 431 , a first conductive layer 432 , a second insulating layer 433 arranged in sequence and considered as a circuit area; and at least one through hole 458 passing through the first conductive layer 452 , the second insulating layer 453 and the second conductive layer 454 . The first insulating layer 451 in the third area 450 includes a solder pad area 456 for exposing the first conductive layer 452 , and the third insulating layer 455 includes a bonding area 457 for exposing the second conductive layer 454 and contacting a bonding head 459 . The surface of the second conductive layer 454 exposed from the bonding area 457 could include a metal layer, which is a single-layer metal layer such as a gold layer, or a double-layer metal layer such as a nickel layer and a gold layer. These materials are used for example to describe the present invention and not intended to limit the invention.
It is noteworthy that the through hole 458 is formed beyond the range of the solder pad area 456 and the bonding area 457 , and the through hole 458 includes an electric conductive material such as nickel or any other substance having a thermal conductive property. In addition, the materials used for the first conductive layer 452 and the second conductive layer 454 could include a copper clad, and an adhesive layer could be included between layers.
Referring to FIGS. 4 and 5 , a flexible printed circuit board and a flow chart of a manufacture process of a flexible printed circuit board according to a preferred embodiment of the present invention are illustrated. In the embodiment, the manufacture process of a flexible printed circuit board 4 comprises the steps of: (Step S 51 ) providing a laminated structure, which is a four-layer structure as shown in the figure, and the laminated structure is divided into a first area 410 , a second area 430 and a third area 450 , and the second area 420 is disposed between the first area 410 and the third area 450 and includes a first insulating layer 411 , a first conductive layer 412 , a second insulating layer 413 , a second conductive layer 414 and a third insulating layer 415 ; and at least one through hole 458 being formed at the first area 410 and the third area 450 and passing through the first conductive layer 412 , second insulating layer 413 and second conductive layer 414 ; (Step S 52 ) removing a part of the first insulating layer 411 in the third area 450 to expose the first conductive layer 412 to define a solder pad area 456 ; and (Step S 53 ) removing a part of the third insulating layer 415 in the third area 450 to expose the second conductive layer 414 to define a bonding area 457 .
In another preferred embodiment of the present invention, a manufacture process of a flexible printed circuit board further comprises the steps of removing the second conductive layer 414 and the third insulating layer 415 in the second area 430 , such that the laminated structure in the first area 410 and the third area 450 includes a first insulating layer 411 , a first conductive layer 412 , a second insulating layer 413 , a second conductive layer 414 and a third insulating layer 415 arranged in sequence, and the laminated structure in the second area 430 includes a first insulating layer 411 , a first conductive layer 412 and a second insulating layer 413 arranged in sequence; depositing an electric conductive material in at least one through hole 458 after forming at least one through hole 458 that passes through the first conductive layer 412 , the second insulating layer 413 and the second conductive layer 414 ; and forming a metal layer on the surface of the bonding area 457 after forming the bonding area 457 . It is noteworthy that the laminated structure further comprises at least one adhesive layer disposed between the first insulating layer, the first conductive layer 412 , the second insulating layer 413 , the second conductive layer 414 and the third insulating layer 415 .
While the invention has been described by way of example and in terms of a preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures.
In summation of the description above, the present invention is novel and useful and definite enhances the performance over the conventional structure and further complies with the patent application requirements and is submitted to the Patent and Trademark Office for review and granting of the commensurate patent rights. | A thermal bonding structure and manufacture process of a flexible printed circuit (FPC) board are disclosed, and the thermal bonding structure includes a laminated structure having a first insulating layer with a solder pad area and showing parts of a first conductive layer, the first conductive layer, a second insulating layer, a second conductive layer, and a third insulating layer with a bonding area such that a part of the second conductive layer is exposed, and at least a through hole passing through the first conductive layer to the second conductive layer for propagating heat energy to fuse a solder. Accordingly, the reduction of heat energy lost in the third insulating layer improves the bonding quality, shortens the bonding period, and maintains the material stability under high temperature resulted from high heat energy. | 7 |
BACKGROUND
[0001] The invention relates generally to lobed connectors, and more particularly to lobed connectors in pipe systems.
[0002] Gasification Technologies provide a stable, affordable energy supply and high efficiency with near-zero pollutants. Gasification based systems also provide flexibility in the production of a wide range of products including electricity, fuels, chemicals, hydrogen, and steam. More importantly, in a time of electricity- and fuel-price spikes, flexible gasification systems provide for operation on low-cost, widely-available feedstocks.
[0003] One of the critical factors in gasification plant economics is maintenance. The ease of maintaining the equipment and equipment reliability can lead to a significant reduction in the overall downtime of the plant. Moreover, an easier process of assembly and disassembly of equipment is also an important factor in facilitating easier maintenance. An improvement in these factors results in enhanced productivity of the plant.
[0004] A coal gasification feed injector nozzle used in a gasification plant generally includes three concentric pipes with portions of the nozzle welded to ends of each pipe. Such a design is referred to as a non-modular design. Flanges used to connect the pipes are unbolted during disassembly of the pipes. Further, the inner pipe is pulled out through the middle pipe and the middle pipe is pulled out through the outer pipe. Feed injector performance has been improved upon by introduction of a nozzle design that features a flared inner nozzle section, which makes it impossible to pull out the inner pipe during disassembly. For this reason, the improved nozzle has been designed to be modular, wherein the entire nozzle is bolted onto adapters on the pipes. Such a design makes pulling the inner pipe out convenient during disassembly as the entire nozzle can first be unbolted and removed. However, the modular design is generally not practical due to bolting, sealing and fabrication cost issues.
[0005] Therefore, it would be desirable to have a design that would address the aforementioned problems.
BRIEF DESCRIPTION
[0006] In accordance with one aspect of the invention, a connector is provided. The connector includes a male adapter including a first base structure and a neck structure protruding out of the said base structure. The neck structure includes a plurality of first lobes extending radially outward from the neck structure. The plurality of first lobes further includes a first mating surface contour on a bottom surface. The connector also includes a female adapter. The female adpater includes a second base structure that includes a plurality of second lobes extending radially inward from the second base structure having a second mating surface contour on a top surface. The second mating surface contour is configured to fit into the first mating surface contour thereby compressing a face seal to induce a compressive stress between the male and the female adapter.
[0007] In accordance with another aspect of the invention, a gasification system is included. The gasification system includes a first end of a first gas pipe configured to connect to a male adapter that includes a first base structure and a neck structure protruding out of the base structure. The neck structure includes a plurality of first lobes extending radially outward from the neck structure. The plurality of first lobes also includes a first mating surface contour on a bottom surface. The gasification system also includes a first end of a second gas pipe configured to connect to the first end of the first gas pipe via a female adapter including a second base structure. The second base structure includes a plurality of second lobes extending radially inward from the second base structure having a second mating surface contour on a top surface. The second mating surface contour is configured to fit into the first mating surface contour thereby compressing a face seal to induce a compressive stress between the male and the female adapter.
DRAWINGS
[0008] These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
[0009] FIG. 1 is a diagrammatic illustration of an exemplary gasification pipe connection system in accordance with an embodiment of the invention;
[0010] FIG. 2 is a diagrammatic illustration of the male adapter in FIG. 1 in accordance with an embodiment of the invention;
[0011] FIG. 3 is a diagrammatic illustration of the female adapter in FIG. 1 in accordance with an embodiment of the invention;
[0012] FIG. 4 is a diagrammatic illustration of a dowel stop configuration of the male adapter and the female adapter in FIG. 1 in accordance with an embodiment of the invention;
[0013] FIG. 5 is a diagrammatic illustration of a ratchet stop configuration of the male adapter and the female adapter in FIG. 1 in accordance with an embodiment of the invention;
[0014] FIG. 6 is a diagrammatic illustration of a two way release configuration of the male adapter and the female adapter in FIG. 1 in accordance with an embodiment of the invention; and
[0015] FIG. 7 is a diagrammatic illustration of a no way release configuration of the male adapter and the female adapter in FIG. 1 in accordance with an embodiment of the invention.
DETAILED DESCRIPTION
[0016] As discussed in detail below, embodiments of the present invention include an improved connection system, wherein the connection system provides a boltless and flangeless mechanism of connecting objects such as gas pipes with desirable sealing. The connection system includes a twist-on mechanism during assembly and twist-off mechanism during disassembly of the objects that makes it convenient for usage. A seal compression force prevents joints that are connected from coming apart.
[0017] In an illustrated embodiment of the invention as shown in FIG. 1 , a cross-sectional view of an exemplary gasification pipe connection system 10 is shown. The system 10 includes two pipes 12 and 14 that are connected to each other via a male adapter 16 and a female adapter 18 . An end of the pipe 12 is attached to the male adapter 16 while an end of the pipe 14 is attached to the female adapter 18 . An annular seal ring 20 provides sealing between the male adapter 16 and the female adapter 18 enabling a desirably tight connection. The male adapter 16 and the female adapter 18 may be fitted inside the pipes 12 and 14 so as to enable desirable clearance outside. In an example, the male adapter 16 and the female adapter 18 are welded inside ends of the pipes 12 and 14 respectively.
[0018] FIG. 2 is a diagrammatical illustration of an exemplary embodiment of the male adapter 16 as referenced to in FIG. 1 . The male adapter 16 includes a first base structure 30 and a neck structure 32 that protrudes out of the first base structure 30 . The base structure 30 includes the seal ring 20 as referenced to in FIG. 1 . The seal ring 20 may include a material that requires minimal torque for installation while maintaining an effective seal. In an example, the seal ring 20 may include a rubber O-ring seal. The neck structure 32 includes a plurality of first lobes 34 that extend radially outward from the neck structure 32 . Each of the first lobes 34 includes a first mating surface contour on a bottom surface 36 . The lobes 34 are circumferential flange sections internal to the male adapter 16 . In an example, the neck structure 32 may include a hollow annular structure. In another example, the first base structure 30 may include a hollow annular structure. As shown in FIG. 1 , the male adapter 16 is welded internal to a pipe 12 . This may lead to a constriction in flow area of a liquid or gas through the pipe 12 . Hence, providing a hollow structure for the male adapter 16 would minimize constriction in the flow of the liquid or gas. Further, it may be desirable to provide a pipe of a diameter slightly larger than that of the flow area in order to accommodate for the constriction in flow.
[0019] FIG. 3 is a diagrammatical illustration of an exemplary embodiment of the female adapter 18 as referenced to in FIG. 1 . The female adapter 18 includes a second base structure 40 that includes a plurality of second lobes 42 extending radially inward from the second base structure 40 . Each of the multiple second lobes 42 include a second mating surface contour on a top surface 44 that is configured to fit into the first mating surface contour of the bottom surface 36 in the male adapter 16 in FIG. 2 . In an example, the second base structure 40 may include a hollow annular structure. As in the case of the male adapter 16 described above, the female adapter 18 is also welded internal to the pipe 14 as shown in FIG. 1 . Accordingly, this may lead to a constriction in flow area of a liquid or gas through the pipe 14 . Hence, providing a hollow structure for the female adapter 18 would minimize constriction in the flow of the liquid or gas.
[0020] During coupling of the male adapter 16 with the female adapter 18 , the first mating surface contour on the bottom surface 36 of the male adapter 16 is configured to twist on and twist off the second mating surface contour on the top surface 44 of the female adapter 18 in specific directions. While twisting on, the seal ring 20 as referenced to in FIG.1 , which is disposed on the first base structure 30 is configured to compress so as to hold the female adapter 18 against the male adapter 16 in an equilibrium position. When the male adapter 16 is twisted on to the female adapter 18 , the seal ring 20 gets compressed initially at least twice as much as that it would in the equilibrium position. Once the equilibrium position is reached, the seal ring 20 releases slightly so as to enable a tight connection between the male adapter 16 and the female adapter 18 . Special contouring of the bottom surface 36 of the male adapter 16 in FIG. 2 and the top surface 44 of the female adapter 18 compresses the seal ring 20 desirably enough to enable required bonding at joints. Various embodiments of contouring of the bottom surface 36 and the top surface 44 are described in detail below in FIGS. 4 , 5 , 6 and 7 .
[0021] In an illustrated embodiment of the invention as shown in FIG. 4 , an exemplary configuration of the first mating surface contour on the bottom surface 36 of the male adapter 16 in FIG. 2 and the second mating surface contour on the top surface 44 of the female adapter 18 in FIG. 3 is provided. The exemplary configuration 50 is referred to as a dowel stop configuration. In the dowel stop configuration 50 , the bottom surface 36 as referenced to in FIG. 2 of the male adapter 16 is twisted on in a direction 52 and twisted off in an opposite direction 54 . In the dowel stop configuration 50 , the first mating surface contour of the male adapter 16 and the second mating surface contour of the female adapter includes inclined planes 58 and 60 respectively. When the inclined planes 58 and 60 of the first mating surface contour and the second mating surface contour respectively, are aligned, the male adapter 16 and the female adapter 18 are in an unstable position. Hence, a dowel pinhole 64 is required in both the inclined planes 58 and 60 such that a dowel pin may be inserted to hold the male adapter 16 and the female adapter 18 together. The compressive annular ring 20 as referenced to in FIG. 1 is compressed so as to create a tight bond between the male adapter 16 and the female adapter 18 when twisted on as shown in a twist on configuration 62 .
[0022] In another illustrated embodiment of the invention as shown in FIG. 5 , an exemplary configuration of the first mating surface contour on the bottom surface 36 of the male adapter 16 in FIG. 2 and the second mating surface contour on the top surface 44 of the female adapter 18 in FIG. 3 is provided. The exemplary configuration 70 is referred to as a ratchet stop configuration. In the ratchet stop configuration 70 , the bottom surface 36 as referenced to in FIG. 2 of the male adapter 16 as referenced to in FIG. 1 are twisted on in a direction 72 and twisted off in the same direction 72 . In the ratchet stop configuration 70 , the first mating surface contour of the male adapter 16 and the second mating surface contour of the female adapter 18 include two inclined planes 76 and a step 78 between the inclined planes 76 . The step 78 allows twisting off the male adapter 16 in only one direction 74 . During twist on, as the second mating surface contour of the female adapter 18 encounters the step 78 of the male adapter 16 , the female adapter 18 falls in place and gets locked. If the female adapter 18 is further twisted in the same direction 72 , it gets unlocked. However, there is no unlocking if twisted in an opposite direction. Such a configuration may be used in a pipe system where a torque is being applied on the pipes in a specific direction. In such a case, the ratchet stop configuration can be designed to twist off only in a direction opposite to the direction of the applied torque. The compressive annular ring 20 as referenced to in FIG. 1 facilitates in providing a tight bond at joint 82 between the male adapter 16 and the female adapter 18 when twisted on as seen in a twist on configuration 80 .
[0023] In another illustrated embodiment of the invention as shown in FIG. 6 , an exemplary configuration 90 of the first mating surface contour on the bottom surface 36 of the male adapter 16 in FIG. 2 and the second mating surface contour on the top surface 44 of the female adapter 18 in FIG. 3 is provided. The exemplary configuration 90 is referred to as a two way release configuration. In the two way release configuration 90 , the bottom surface 36 as referenced to in FIG. 2 of the male adapter 16 as referenced to in FIG. 1 may be twisted on in a direction 92 and twisted off in either direction 92 or 94 . In the two way release configuration 90 , the first mating surface contour of the male adapter 16 and the second mating surface contour of the female adapter includes three inclined planes 96 . The three inclined planes 96 do not prevent twisting off in either direction, as there is no barrier like the step 78 in FIG. 5 . Slope of the inclined planes 96 is directly proportional to torque applied during twisting on of the male adapter 16 and the female adapter 18 . Hence, a gentler slope may be designed for an easier twist on process. The compressive annular ring 20 as referenced to in FIG. 1 facilitates in providing a tight bond between the male adapter 16 and the female adapter 18 when twisted on as seen in a twist on configuration 98 .
[0024] In another illustrated embodiment of the invention as shown in FIG. 7 , an exemplary configuration 100 of the first mating surface contour on the bottom surface 36 of the male adapter 16 in FIG. 2 and the second mating surface contour on the top surface 44 of the female adapter 18 in FIG. 3 is provided. The exemplary configuration 100 is referred to as a no way release configuration. In the no way release configuration 100 , the bottom surface 36 as referenced to in FIG. 2 of the male adapter 16 as referenced to in FIG. 1 may be twisted on in a direction 102 and may not be twisted off in any direction. In the no way release configuration 100 , the first mating surface contour of the male adapter 16 and the second mating surface contour of the female adapter 18 include an inclined plane 104 , a straight plane 106 and a step 108 between the inclined plane 104 and the straight plane 106 . The step 108 acts as a stop lock that locks the male adapter 16 and the female adapter 18 in place and does not give any degree of freedom to be twisted off. Hence, when the inclined planes 104 of the male adapter 16 and the female adapter 18 align, the step 108 locks the male adapter and the female adapter thus preventing them from twisting off. The compressive annular ring 20 as referenced to in FIG. 1 facilitates in providing a tight bond between the male adapter 16 and the female adapter 18 when twisted on as seen in a twist on configuration 110 .
[0025] Some of the non-limiting advantages of the above mentioned connection system are non-inclusion of bolts or flanges to join parts in the system. In addition, the aforementioned embodiments of the invention may be fitted inside pipes or other systems that need to be connected thus enabling an easier process of assembly and disassembly.
[0026] While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention. | A connector including a male adapter and a female adapter is provided. The male adapter includes a first base structure and a neck structure protruding out of the base structure. The neck structure includes a multiple of first lobes extending radially outward from the neck structure. The first lobes include a first mating surface contour on a bottom surface. The female adapter includes a second base structure. The second base structure includes a second mating surface contour on a top surface and is configured to fit into said first mating surface contour thereby compressing a face seal to induce a compressive stress between said male and said female adapter. | 5 |
BACKGROUND OF THE INVENTION
This invention relates to a transmission control system, and more particularly to a calibrating method for determining key parameters relating to the operation and control of the transmission control clutches.
Some manufacturers have used versions of electrohydraulic transmission controls which include proportionally controlled valves. In such systems with proportional control valves it is possible and desirable to accurately control the torque capacities of the clutches during engagement. While the electrical command supplied to the control valve may be very precise, manufacturing tolerances in the valves and transmission cause large variations on an actual vehicle. If it is known what electrical command corresponds to the initial clutch engagement pressure which causes a clutch to just begin carrying torque, then this command could be used to modify the shift command for that clutch during shifting to provide optimized control. For example, U.S. Pat. No. 4,855,913, issued Aug. 8, 1989 to Brekkestran et al., discloses that the key parameters in the control system include the initial clutch engagement pressure (represented by DC-MAX) and the fast-fill clutch delay (represented by T1). The Brekkestran reference further states that DC-MAX and T1 must be determined by laboratory or field tests. However, the Brekkestran reference does not disclose any method for determining these values.
A calibrating method or a method of determining the pressure necessary to achieve clutch engagement in a microprocessor-based transmission control system is described in U.S. Pat. No. 4,989,471, issued on Feb. 5, 1991 to Bulgrien. The Bulgrien method includes braking the transmission output shaft, then gradually increasing the clutch pressure and saving a value corresponding to the clutch pressure at which the engine speed begins to decrease. However, this method relies upon the resistance to rotation due to use of the vehicle brakes to prevent rotation of the transmission output shaft. Such a procedure could be dangerous if the vehicle brakes are not applied or if the brakes fail, because then undesired vehicle motion could result during calibration. The Bulgrien patent also illustrates an alternate method of calibrating a clutch by sensing when the clutch transmits sufficient torque to move the vehicle. This alternate method requires that the vehicle be placed in a position where vehicle motion is not a safety concern, and the results of such a method will vary depending upon the terrain on which the vehicle is placed. The Bulgrien patent also depends on sensing variations in engine speed, and is therefore susceptible to variations in engines and engine governors.
U.S. Pat. No. 5,082,097, issued on Jan. 21, 1992 to Goeckner et al. discloses a calibrating system or a system for determining a current signal corresponding to the point at which the clutch begins to transmit torque. This system requires sensing either vehicle movement or engine speed droop, and thus depends on sensing variations in engine speed, and is therefore susceptible to variations in engines and engine governors, or requires possibly dangerous vehicle movement.
Another calibration method is described in U.S. Pat. No. 5,224,577, issued Jun. 7, 1993 to Falck et al. and assigned to the assignee of the present application. This method also involves sensing engine speed droop, and is therefore susceptible to variations in engines and engine governors.
Another calibration method is disclosed in U.S. Pat. No. 5,337,871, issued Aug. 16, 1994 to Testerman, and assigned to the assignee of the present application. However, this method requires pressure sensors, which are expensive, and which are not as accurate or reliable as rotation speed sensors.
Another calibration method is disclosed in U.S. patent application Ser. No. 08/800,431, filed Feb. 8, 1997 now U.S. Pat. No. 5,842,375, and assigned to the assignee of the present application. In this method the target deceleration time used for determining the hold pressure must be determined empirically as an average based on measurements taken from a number of sample transmission. However, if the actual parasitic drag of a production transmission is significantly different from that of the sample transmissions, then the torque produced by the resulting hold pressure of the clutch being calibrated would be different from what is desired. Accordingly, it would be desirable to measure a parasitic drag time for each transmission prior to determining the hold pressure of each clutch, and then use the actual parasitic drag time to calculate the target deceleration time required to produce a given hold torque.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a method of calibrating or determining key parameters for the control of proportional control valves for a powershift transmission.
Another object of the invention is to provide such a method which is not effected by variations in parasitic drag for different transmissions.
These and other objects are achieved by the present invention wherein a parasitic drag time is measured, the measured parasitic drag time is used to calculate the target deceleration time required to produce a given hold torque, and then the hold pressure of each clutch is determined.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic block diagram of a microprocessor-based transmission control system to which the present invention is applicable.
FIG. 2 is a schematic representation of a transmission to which the present invention is applicable.
FIG. 3 illustrates the relationship between FIGS. 4A, 4B and 4C.
FIGS. 4A, 4B and 4C together comprise a simplified logic flow diagram illustrating a hold pressure calibration method of the present invention.
FIG. 5 illustrates the relationship between FIGS. 6A, 6B and 6C.
FIGS. 6A, 6B and 6C together comprise a simplified logic flow diagram illustrating an alternate hold pressure calibration method of the present invention.
DETAILED DESCRIPTION
As shown in FIG. 1, a vehicle power train includes an engine 10 which drives, via input shaft 13, a power shift transmission 12, which, via output shaft 14 and differential 15, drives wheels 16. The power shift transmission 12 is operated by a set of electrohydraulic valves 18 which are controlled by signals from a microprocessor based transmission controller 20. The transmission 12 may be a transmission such as a DF 150 or DF 250 powershift transmission manufactured by Funk Manufacturing, Inc., but the invention could be applied to other powershift transmissions as well.
The transmission controller 20 is connected to a display 22 and to a gearshift lever 24 via a gearshift switch/encoder unit 26 such as commercially available from Funk Manufacturing for use with its production DF 150 and DF 250 powershift transmissions. The transmission controller 20 is also connected to an electrical jumper 28. Mag pickup rotation speed sensors 30, 32, 34 and 36 provide rotation speed signals to the controller 30, as will be described in more detail hereinafter.
The transmission control unit 20 includes a commercially available microprocessor (not shown) which, in response to connection of jumper 28, executes a computer program which implements operation of the calibration methods described hereinafter. The transmission control unit 20 also includes valve drivers (not shown) which provide variable duty cycle pulse-width-modulated voltage control signals to the valves 18. The transmission control unit 20 and the valve drivers (not shown) will generate such control signals as a function of various sensed and operator determined inputs in order to achieve a desired pressure in the clutches and to thereby control the shifting of the transmission 12 in a desired manner. However, the present invention is not concerned with the control of the shifting of the transmission 12, the transmission 12 itself, or the valves 18, since the present invention is concerned only with the calibration of certain parameters. The method of the present invention is implemented by the control unit 20 which executes a computer program, which includes portions related to the algorithms illustrated by FIGS. 4A, 4B and 4C, and FIGS. 6A, 6B and 6C. Further information on other aspects of the computer program is included in U.S. patent application Ser. No. 08/800,431 now U.S. Pat. No. 5,842,375, which is hereby incorporated by reference herein.
Referring to FIG. 2, the transmission shown has 6 clutches 55, 60, 65, 69, 74 and 79. The input shaft 13 is mounted to gear 52 that meshes with gear 53 and 58. Shafts 54 and 56 turn the same speed when clutch 55 is fully engaged. Shafts 59 and 61 turn the same speed when clutch 60 is fully engaged. Shafts 64, 56, 61 and 87 are connected to gears 63, 57, 62 and 68 respectively. Shafts 64 and 66 turn the same speed when clutch 65 is engaged. Shafts 87 and 88 turn the same speed when clutch 69 is engaged. Shafts 73 and 75 turn the same speed when clutch 74 is engaged. Shafts 78 and 80 turn the same speed when clutch 79 is engaged. In order to transmit power from input shaft 13 to output shaft 84, three clutches need to be engaged: either 55 or 60, and either 65 or 69, and either 74 or 79. Gears 63, 57, 62, and 68 are in constant mesh as are gears 67, 72, 77 and 70.
Mag pickup speed sensor 30 monitors output speed. Mag pickup speed sensor 32 monitors the speed of gear 70 which also provides calculated speeds for gears 67, 72 and 77. Mag pickup speed sensor 34 monitors input speed. Mag pickup speed sensor 36 monitors the speed of gear 68 which also provides calculated speeds for gears 62, 57 and 63. Gear 76 is connected to shaft 75 and gear 81 is connected to shaft 80. Gears 76, 81 and 83 all mesh to provide power out at shaft 84. Each of clutches 55, 60, 65, 69, 74 and 79 are activated (engaged) with hydraulic pressure supplied from electrohydraulic valves 18.
CALIBRATION METHODS
Hold Pressure-Deceleration
Referring now to FIGS. 3, 4A, 4B and 4C, the calibration method shown therein can be used to determine the hold pressures for all the clutches. The automatic calibration procedure is enabled by connecting the calibration jumper 28 to the transmission controller 20. Although not shown in FIG. 3, the controller continually checks to ensure the park brake (not shown) is applied, that oil temperature is above 69° F., that engine speed is running at about 1500 rpm, and that no sustained output shaft speed is detectable. If any of the checks determine a fault, the routine aborts. Once the calibration jumper 28 is installed and the engine speed and park brake are set, the shift lever 24 is moved from its neutral to its forward position to start the calibration process. Table 1 lists the clutch combinations for determining hold pressures for all the clutches.
TABLE 1______________________________________Hold Pressure-DecelerationClutch Calibrated Clutch 1 Clutch 2 Gear Speed______________________________________55 60 65 6860 55 65 6865 55 74 6869 55 74 6874 55 65 7079 55 65 70______________________________________
This calibration method will now be described for the calibration of clutch 55, with clutch 1 being clutch 60, clutch 2 being clutch 65 and with the speed of gear 68 being sensed by mag pickup 36. In step 495, clutches 60 and 65 are fully engaged. Step 496 checks speed sensor 36 to see if proper speed of gear 68 has been sustained for 500 milliseconds(ms). Once this gear speed has been sustained for 500 ms, clutch 60 is released in step 497. Then, determines the amount of time, Tpara -- d, required for the rotation speed of gear 68 to decrease by a certain amount due to the parasitic drag of the involved transmission components. Step 499 causes steps 495-498 to be repeated at least three times and then until the last three measured Tpara -- d times are within 5% of each other. Step 500 then calculates a target deceleration time value (target -- decel), using average of the last three Tpara -- d deceleration times and the following equation,
target.sub.-- decel=[low.sub.-- rpm-(engine cal.sub.-- spd-x.sub.-- rpm)]/[(-Th/I)+(low.sub.-- rpm-(engine cal.sub.-- spd-x.sub.-- rpm))/Tpara.sub.-- d],
where low -- rpm is the approximately 200 rpm low speed cut off used to measure deceleration times, engine cal -- spd is approximately 1600 rpm, x -- rpm is approximately 150 rpm (both engine cal -- spd and x -- rpm are reset values selected for the particular type of transmission being calibrated), Th is the desired hold torque of the clutch being calibrated, I is the inertia of the rotating parts downstream of the clutch being calibrated which is calculated from the characteristics of the transmission, and Tpara -- d is the parasitic drag deceleration time determined in step 500.
In step 501 an initial hold pressure, for example, 30 psi is applied to clutch 55. In step 502, clutches 60 and 65 are fully engaged, thus causing rotation of both the input and output elements of clutch 55 to rotate. Step 503 checks speed sensor 36 to see if proper speed of gear 68 has been sustained for 500 milliseconds(ms). Once this gear speed has been sustained for 500 ms, clutch 60 is released in step 504.
The rotation speed of the gears and shafts connected to gear 68 will begin to slow down because of friction and because clutch 55 is less than fully engaged. Step 505 determines the amount of time (deceleration time) required for the rotation speed of gear 68 to decrease by a certain amount. In step 505, if the measured deceleration time is less than the calculated and stored target deceleration time (target -- decel), then step 506 causes steps 501-504 to be repeated. If in step 507 the deceleration time is again measured, and if it is still less than target -- decel, then step 508 causes an appropriate error message to appear on display 22 and step 509 directs the routine to determine the hold pressure of another clutch.
If, in steps 505 or 507, the measured deceleration time is not less than target -- decel then the routine proceeds to step 510, which increments the hold pressure by one increment. Step 511 checks to see if the hold pressure is greater than or equal to the maximum hold pressure allowable. If it is, step 512 causes an error message to be displayed and step 513 directs the routine to determine the hold pressure of another clutch. Otherwise, step 511 directs the algorithm to step 514 which re-engages clutch 60 so that the output of clutch 55 (shaft 56 and gear 57) will again be rapidly rotating. Step 515 then again checks that a certain gear speed has been sustained for 500 ms, then step 516 releases clutch 60. Step 517 again compares deceleration time to target -- decel time. If it is greater, then the routine proceeds to step 510 and increments the hold pressure.
Eventually, when the pressure applied to clutch 55 attains the hold pressure value, clutch 55 will begin to engage and will transmit torque to shaft 56 and gear 57 which tends to slow the rotation of gear 57 and cause gear 57 to rotate in a direction opposite to the rotation caused by the engagement of clutch 60. When this happens, in step 517, the measured deceleration time will be less than the target -- decel time and the hold pressure is stored by step 518. Step 519 repeats steps 501 through 518 for other clutches to be calibrated. Thus, the hold pressure has been determined by sensing a rotation speed of internal transmission component--gear 68, and without sensing engine speed droop and without causing vehicle movement.
Hold Pressure-Acceleration
FIGS. 5, 6A and 6B show an alternate calibration method wherein hold pressure is determined by measuring the acceleration of an internal component of the transmission 12. For this particular transmission, this method may be applied to all clutches except 74 and 79. Table 2 lists the clutch combinations for determining hold pressures for clutches 55, 60, 65 and 69.
TABLE 2______________________________________Hold Pressure-AccelerationClutch Calibrated Clutch 1 Clutch 2 Gear Speed______________________________________55 74 65 6860 74 65 6865 74 55 7069 74 55 70______________________________________
FIGS. 6A, 6B and 6C will now be described for the calibration of clutch 55, with clutch 1 being clutch 74, clutch 2 being clutch 65 and with the speed of gear 68 being sensed by mag pickup 36. In step 595, clutches 74 and 65 are fully engaged. Step 596 checks speed sensor 36 to see if proper speed of gear 68 has been sustained for 500 milliseconds(ms). Once this gear speed has been sustained for 500 ms, clutch 74 is released in step 597. Then, step 598 determines the amount of time, Tpara -- a, required for the rotation speed of gear 68 to increase by a certain amount due to the parasitic drag of the involved transmission components. Step 599 causes steps 595-598 to be repeated at least three times and then until the last three measured Tpara -- a times are within 5% of each other. Step 600 then calculates a target acceleration time value (target -- accel), using average of the last three Tpara -- a acceleration times and the following equation,
target.sub.-- accel=[(engine cal.sub.-- spd-x.sub.-- rpm)-low.sub.-- rpm]/[(Th/I)+((engine cal.sub.-- spd-x.sub.-- rpm)-low.sub.-- rpm)/Tpara.sub.-- a],
where Tpara -- a is the parasitic drag acceleration time determined in step 600, and the other factors are as previously described in connection with the equation for target -- decel.
In step 601, clutch 74 and clutch 65 are fully engaged, thus preventing rotation of the output of clutch 55 and of gear 57. In step 602 an initial hold pressure is applied to clutch 55. Step 603 checks to verify the speed of gear 68 is 0 rpm for at least 500 ms. Step 604 releases clutch 74, allowing whatever torque is transmitted across clutch 55 to accelerate gear 68.
Step 605 measures the time it takes to accelerate the gear 68 up to a predetermined target speed for the initial hold pressure. If this time is less than the target -- accel time then steps 601 through 604 are repeated in step 606. Step 607 measures the time it takes to accelerate gear 68 to the predetermined target speed. If this time is still less than the target acceleration time then step 608 displays on display 12 an appropriate error message and the routine continues on to finding the hold pressure of the next clutch in step 609.
If, in steps 605 or 607, the acceleration time to the predetermined speed is not less than target -- decel then routine proceeds to step 610 and hold pressure is incremented and applied to clutch 55. Step 611 causes step 612 to display an error message if the hold pressure is greater than or equal to the maximum hold pressure, and the routine proceeds to the next clutch in step 613. Otherwise, step 614 engages clutch 74 and step 615 again checks that the speed of gear 68 is 0 rpm for 500 ms, and the routine proceeds to step 616 where clutch 74 is released.
The releasing of clutch 74 allows whatever torque is transmitted across clutch 55 to accelerate gear 68. Step 617 again compares the measured acceleration time to the stored reference time (target -- accel). If the measured acceleration time is greater than target -- accel, it means that the pressure applied to clutch 55 has not started to engage it yet, and the hold pressure is incremented in step 610. The loop continues until the measured acceleration time is less than the target -- accel time and the hold pressure is then stored as the calibration value by step 618. Step 619 repeats the process for the other clutches listed in Table 2.
It should be noted that with this method only a minimal torque is transmitted through clutch 55. This results in a very small effect on engine pull down so that the calibration results are not affected by variations in engine characteristics.
While the present invention has been described in conjunction with a specific embodiment, it is understood that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, this invention is intended to embrace all such alternatives, modifications and variations which fall within the spirit and scope of the appended claims. | The hydraulically operated clutch elements of a powershift transmission have hold pressures which are calibrated by determining a parasitic drag time value represent a speed change of a clutch component due to a friction characteristic of the transmission, by calculating a target speed change value from the parasitic drag time valueas, and by deriving the clutch calibration values from the target speed change value. | 8 |
TECHNICAL FIELD
Embodiments of the present disclosure relate to a display device.
BACKGROUND
Dual-view display devices have a main function of displaying different images at different angles so that through patterned blocking by means of a grating, an image displayed on pixels of odd rows or an image displayed on pixels of even rows is visible respectively for viewers from left side and viewers from right side. Therefore, viewers at different locations can see different images from different angles.
However, as known to the inventors, there has not been a display device which can achieve dual-view display and stereoscopic display at the same time in the art so far.
SUMMARY
One of the objects of the present disclosure is to provide a display device, in which display with dual-field of viewing can be performed and stereoscopic images are visible in both of the two fields of view.
To achieve the above object, at least one embodiment of the present disclosure provides a display device, comprising a first panel and a second panel disposed at a space from the first panel. The first panel comprises a plurality of first display groups, each of which comprises a plurality of rows of sub-pixels. The second panel is a transparent panel and comprises a plurality of second display groups, each of which comprises a plurality of rows of sub-pixels. The respective rows of sub-pixels in the plurality of first display groups correspond to the respective rows of sub-pixels in the plurality of second display groups one for one. The display device further comprises a multi-viewpoint grating which guides the light emitted from the plurality of rows of sub-pixels in respective first display groups in the first panel to the respective plurality of rows of sub-pixels in the second display groups on the second panel in a manner of one for one, so that a plurality of fields of view are formed on a light-emitting face of the second panel and a stereoscopic image is visible in each field of view. The number of fields of view is the same as the number of rows of sub-pixels in the first display group.
According to one embodiment of the present disclosure, the first display group comprises two rows of sub-pixels, and the multi-viewpoint grating is a dual-viewpoint grating.
According to one embodiment of the present disclosure, the multi-viewpoint grating is disposed between the first panel and the second panel, and the first panel, the second panel and the multi-viewpoint grating meet the requirement of the following formula:
a/h=b/ ( h′−h ),
wherein a is a dimension of the sub-pixels of the first panel, b is a dimension of the sub-pixels of the second panel, h′ is a depth of field of stereoscopic display of the display device, and h is a distance between the multi-viewpoint grating and the first panel.
According to one embodiment of the present disclosure, the first panel is a liquid crystal panel, and the display device further comprises a backlight source which is disposed at a light-incident side of the first panel.
According to one embodiment of the present disclosure, the first panel is an organic light-emitting diode panel.
According to one embodiment of the present disclosure, the first panel and the second panel are both liquid crystal panels, the display device further comprises a backlight source, and the multi-viewpoint grating is disposed between the backlight source and the first panel.
According to one embodiment of the present disclosure, the multi-viewpoint grating comprises a first substrate, a second substrate cell-assembled with the first substrate, a plurality of strip-like electrodes disposed on the first substrate with an interval therebetween, a plate-like electrode disposed on the second substrate, a liquid crystal layer filled between the first substrate and the second substrate, and a grating control circuit configured to supply signals respectively to the strip-like electrodes and the plate-like electrode.
According to one embodiment of the present disclosure, the strip-like electrodes and the plate-like electrode are both made of transparent conductive material.
According to one embodiment of the present disclosure, the display device comprises a plurality of input modules, the number of which corresponds to the plurality of fields of view one for one.
The display device provided by the embodiments of the present disclosure guides the light emitted from the respective sub-pixels of the first panel to the respective sub-pixels on the second panel which are corresponding to the respective sub-pixels of the first panel one for one by means of the multi-viewpoint grating, and thus can achieve not only multi-view display but also naked-eye stereoscopic display can be achieved and the requirement of users for multi-view display and stereoscopic display is met.
BRIEF DESCRIPTION OF THE DRAWINGS
In order to clearly illustrate the technical solutions of the embodiments of the disclosure, the drawings of the embodiments will be briefly described in the following; it is obvious that the drawings described below are only related to some embodiments of the disclosure and thus are not limitative of the disclosure.
FIG. 1 is an illustrative view of a display device according to one embodiment of the present disclosure; and
FIG. 2 is an illustrative view of a display device according to another embodiment of the present disclosure.
DETAILED DESCRIPTION
In order to make objects, technical details and advantages of the embodiments of the disclosure apparent, the technical solutions of the embodiment will be described in a clearly and fully understandable way in connection with the drawings related to the embodiments of the disclosure. It is obvious that the described embodiments are just a part but not all of the embodiments of the disclosure. Based on the described embodiments herein, those skilled in the art can obtain other embodiment(s), without any inventive work, which should be within the scope of the disclosure.
As illustrated in FIG. 1 and FIG. 2 , one embodiment of the present disclosure provides a display device comprising a first panel 100 and a second panel 200 disposed at a distance from the first panel 100 . The first panel 100 comprises a plurality of first display groups each of which comprises a plurality of rows of sub-pixels. The second panel 200 is a transparent panel and comprises a plurality of second display groups each of which comprises a plurality of rows of sub-pixels. The respective rows of sub-pixels in the first display groups correspond to the respective rows of sub-pixels in the second display groups one for one. The display device further comprises a multi-viewpoint grating 300 which is capable of guiding the light emitted from the plurality of rows of sub-pixels in each first display group in the first panel 100 to the respective plurality of rows of sub-pixels in the second display group on the second panel 200 , so that a plurality of fields of view are formed on the light-emitting face of the second panel 200 and a stereoscopic image is visible in each field of view. The number of fields of view is the same as the number of rows of sub-pixels in the first display group.
In each of the first display groups of the first panel, each row of sub-pixels corresponds to one field of view. For example, each of the first display groups of the first panel comprises N rows of sub-pixels. Thus, in all of the first display groups, a first row of sub-pixels forms a complete image, a second row of sub-pixels forms a complete image, and so on. The image formed by the first row of sub-pixels can be different from the image formed by other rows of sub-pixels or can be the same as the latter.
In each of the second display groups of the second panel, each row of sub-pixels corresponds to one field of view. For example, each of the second display groups of the second panel comprises N rows of sub-pixels. Thus, in all of the second display groups, a first row of sub-pixels forms a complete image, a second row of sub-pixels forms a complete image, and so on. The image formed by the first row of sub-pixels can be different from the image formed by other rows of sub-pixels or can be the same as the latter. The image displayed by the first row of sub-pixels in the second display group of the second panel and the image displayed by the first row of sub-pixels in the first display group of the first panel match with each other, and so on.
Since the first panel 100 is disposed at the light-incident side of the second panel 200 , the light emitted from the first panel 100 serves as a backlight source of the second panel 200 . Therefore, the multi-viewpoint grating 300 is not only a multi-viewpoint grating of the first panel 100 , but also a multi-viewpoint grating of the second panel 200 . That is to say, the multi-viewpoint grating 300 can guide the light emitted from the respective rows of sub-pixels of the first panel 100 to the respective sub-pixels of the second panel 200 in a manner of one for one, and can guide the light emitted from the respective rows of sub-pixels of the second panel 200 to two different fields of view (Field of View 1 and Field of View 2 as illustrated in FIG. 1 and FIG. 2 ). The sub-pixels on the second panel 200 which receive the light have the same color as the sub-pixels on the first panel which emit the light. As illustrated in FIG. 1 and FIG. 2 , red sub-pixels on the second panel 200 receive the light emitted from red sub-pixels on the first panel 100 , green sub-pixels on the second panel 200 receive the light emitted from green sub-pixels on the first panel 100 , and blue sub-pixels on the second panel receive the light emitted from blue sub-pixels on the first panel 100 .
It can be readily appreciated that in the present disclosure, the first row of sub-pixels among a plurality of first image groups of the first panel 100 displays a type of image (called a first row image in the present disclosure), while the second row of sub-pixels among the plurality of first image groups of the first panel 100 displays another type of image (called a second row image in the present disclosure), and so on. The first row of sub-pixels among a plurality of second image groups of the second panel 200 displays an image matching with the first row image of the first panel 100 , and the second row of sub-pixels among the plurality of second image groups of the second panel 200 displays an image matching with the second row image of the first panel 100 .
Hereinafter, it is explained how the image on the first panel 100 “matches with” the image on the second panel 200 by taking an image on the first row of the first panel 100 as an example. Since the second panel 200 is transparent, in a field of view in front of the second panel 200 , an image displayed by a first row of sub-pixels in the plurality of second image groups of the second panel 200 is visible, and an image on the first row displayed by the first panel 100 is visible through the second panel 200 . The image displayed by the first row of sub-pixels in the plurality of second image groups of the second panel 200 and the image on the first row of the first panel 100 are arranged in a manner that one is behind the other, so that by fusion in the human brain, a visual effect of stereoscopic image can be generated. As long as the image on the first row of the first panel 100 and the image displayed on the first row of sub-pixels among a plurality of second image groups of the second panel 200 are fused in the human brain so that the human being can see an visual effect of stereoscopic image, it can be said that the image on the first row of the first panel 100 matches with the image displayed on the first row of sub-pixels in the plurality of second image groups of the second panel 200 . Matching of the respective rows of sub-pixels are similar to the above and a detailed explanation is omitted here.
The display device according to the embodiments of the present disclosure guides the light emitted from the respective sub-pixels of the first panel 100 and the light emitted from the respective sub-pixels of the second panel 200 through the multi-viewpoint grating 300 , which can achieve not only multi-view display but also naked-eye stereoscopic display and which meets the requirement of users for multi-view display and stereoscopic display.
In the present disclosure, the position at which the multi-viewpoint grating is disposed is not particularly limited, as long as it can guide the light in a manner as described above.
To observe an image with relatively high resolution in the respective fields of view, in one embodiment of the present disclosure, the display device can be dual-viewpoint display device and the multi-viewpoint grating 300 can be dual-viewpoint grating. That is to say, the first display group comprises two rows of sub-pixels and the second display group also comprises two rows of sub-pixels.
In one embodiment of the present disclosure, the multi-viewpoint grating 300 can guide the light emitted from the odd rows of sub-pixels of the first panel 100 to one of the odd rows of sub-pixels and the even rows of sub-pixels of the second panel 200 , and guide the light emitted from the even rows of sub-pixels of the first panel 100 to the other of the odd rows of sub-pixels and the even rows of sub-pixels of the second panel 200 . The sub-pixels on the second panel 200 which receive the light have the same color as the sub-pixels on the first panel 100 which emit the light, so that two fields of view (i.e., the Field of View 1 and the Field of View 2 illustrated in the drawings) are formed on the light-emitting face of the second panel 200 and a stereoscopic image can be observed in each field of view.
As the first embodiment of the present disclosure, as illustrated in FIG. 1 , the multi-viewpoint grating 300 can be disposed between the first panel 100 and the second panel 200 . The first panel 100 , the second panel 200 and the multi-viewpoint grating 300 meet the requirement of the following equation:
a/h=b/ ( h′−h ),
wherein a is a dimension of the sub-pixels of the first panel 100 , b is a dimension of the sub-pixels of the second panel 200 , h′ is a depth of field of the stereoscopic display of the display device, and h is a distance between the multi-viewpoint grating 300 and the first panel 100 .
In the present disclosure, the pitch of the multi-viewpoint grating 300 and the distance h between the multi-viewpoint grating 300 and the first panel 100 can be designed according to the design rule for the dual-view display, and the depth of field of the stereoscopic display of the display device can be designed according to conditions for achieving “a real stereoscopic display”. All these are readily known by those skilled in the art and a detailed description is omitted here.
Here, the “dimension of the sub-pixels” refers to the width of the sub-pixels, i.e., the distance extended laterally by the sub-pixels.
In the present disclosure, the second panel 200 can be a liquid crystal panel, but there is no special requirement on the first panel 100 . The first panel 100 can be an organic light-emitting diode (OLED) panel, or can be a liquid crystal panel. To obtain a relatively high resolution, the first panel 100 can be selected as an organic light-emitting diode panel. Alternatively, to save energy, the first panel can be selected as a liquid crystal panel. The operator can select the first panel as an organic light-emitting diode panel or a liquid crystal panel according to actual applications of the display device.
When the first panel is a liquid crystal panel, the display device further comprises a backlight source (not illustrated) which is disposed at the light-incident side of the first panel.
To save energy, the first panel 100 and the second panel 200 can be both provided as liquid crystal panels. As a second embodiment of the present disclosure, as illustrated in FIG. 2 , the first panel 100 and the second panel 200 are both liquid crystal panels. The display device further comprises a backlight source (not illustrated). The multi-viewpoint grating 300 is disposed between the backlight source and the first panel 100 .
When the same display device is used by two users, one user views it in the Field of View 1 , while the other user views it in the Field of View 2 . The two users can view different stereoscopic images.
In the present disclosure, the structure of the multi-viewpoint grating 300 is not limited. For example, the multi-viewpoint grating 300 can be a slit grating or a lens grating.
As one embodiment of the present disclosure, the multi-viewpoint grating 300 can be a liquid crystal grating. For example, the multi-viewpoint grating 300 comprises a first substrate, a plurality of strip-like electrodes disposed on the first substrate with an interval therebetween, a second substrate cell-assembled with the first substrate, a plate-like electrode disposed on the second substrate, a liquid crystal layer filled between the first substrate and the second substrate, and a grating control circuit configured to supply a first signal to the strip-like electrodes and to supply a second signal to the plate-like electrode.
When the grating control circuit supplies a first signal and a second signal to the strip-like electrodes and the plate-like electrode respectively, the liquid crystalline molecules between the strip-like electrodes and the plate-like electrode are deflected so that light cannot pass through the portions corresponding to the strip-like electrodes but can only pass through the portions between adjacent two strip-like electrodes, thereby forming a plurality of fields of view at the light-emitting side of the second panel.
To make the display device capable of being switched between multi-field of view and a single field of view, in one embodiment, the strip-like electrodes and the plate-like electrode are both made of transparent conductive material. When the grating control circuit supplies no first signal and no second signal to the strip-like electrodes and the plate-like electrode, the liquid crystalline molecules are not deflected and light can pass through the liquid crystalline molecules, so that a single field of view is formed at the light-emitting side of the second panel.
When the display device is in a mode of multi-field of view, a plurality of viewers are able to watch the desired contents in different fields of view. When the display device is in a mode of single field of view, viewers can observe an image with relatively high resolution at the light-emitting side of the second panel. Viewers can make their choices to set the display device either in a mode of multi-field of view or in a mode of single field of view as required.
In one embodiment, the display device comprises a plurality of input modules, the number of which corresponds to the plurality of fields of view one for one. Viewers in different fields of view can operate on the display interface within the field of view by using a corresponding input module.
The foregoing are merely exemplary embodiments of the disclosure, but are not used to limit the protection scope of the disclosure. The protection scope of the disclosure shall be defined by the attached claims.
The present disclosure claims priority of Chinese Patent Application No. 201410323544.1 filed on Jul. 8, 2014, the disclosure of which is hereby entirely incorporated by reference as a part of the present disclosure. | A display apparatus comprises a first panel ( 100 ) and a second panel ( 200 ) disposed in a spaced manner with the first panel ( 100 ). The first panel ( 100 ) comprises multiple first display groups and each first display group comprises multiple columns of sub pixels. The second panel ( 200 ) is a transparent panel and comprises multiple second display groups, and each second display group comprises multiple columns of sub pixels. Sub pixels in the first display groups are in a one-to-one correspondence with sub pixels in the second display groups. The display apparatus also comprises a multi-vision raster ( 300 ). The multi-vision raster can guide light sent by multiple columns of sub pixels in the first display groups on the first panel ( 100 ) to multiple columns of sub pixels of corresponding second display groups on the second panel ( 200 ) in a one-to-one correspondence manner, so that multiple vision fields are formed on a light emission surface of the second panel ( 200 ) and in each vision field, a three-dimensional image can be seen and the number of the vision fields is the same as the number of the columns of the sub pixels in the first display groups. When multiple users use the same display apparatus, the multiple users can see different three-dimension images in multiple different vision fields. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to the food processing apparatus or, more particularly, to an automatic continuous food frying device for commercial use, such as for use by the food processing industry, or the like.
An automatic continuous food frying device according to the prior art is illustrated in FIG. 9, and is so constructed that frying oil disposed in an oil tank is heated by fire tubes (35) of the boiler provided at the bottom of the oil tank, and pieces of raw food (37) is introduced through an opening (36) into the oil tank where it is fried in the course of being conveyed through the oil to an exit opening (40) for removing the fried food by means of a submerging net conveyor (38) and a carrying net conveyor (39). With this construction, there is the drawback in that, since the fire tubes are provided at the bottom of the oil tank, it is difficult to keep the temperature of the frying oil uniform and, hence, to prepare uniformly fried food nicely done which is nicely cooked. Furthermore, because of low-temperature layers of oil encircling pieces of food to be fried, the heat exchangeability of the frying oil is rather poor and, hence, there were limitations to the frying capacity of the device. Still another drawback of the conventional frying device lies in that, since it is pretty difficult to remove the scum from the frying oil, there is caused an early deterioration of the frying oil.
With the aforementioned circumstances in view, it is the object of the present invention to provide an automatic continuous food frying device wherein an improvement in the uniformity of the frying oil temperature, an improvement in the heat exchangeability and augmentation of the frying capacity, and the prevention in an early deterioration of the frying oil, is achieved.
BRIEF SUMMARY OF THE INVENTION
In an automatic continuous food frying device comprising an oil tank to be filled with frying oil, a heating means for heating said heating oil and a means for conveying food to be fried, submerged in the frying oil, there is provided inside the oil tank an impeller having many broad vanes, so as to keep the frying oil circulating in the oil tank by running said impeller. There is also provided a filter midway through the oil circuit, thereby solving the aforementioned problems experienced by the prior art.
By virtue of the flowing frying oil, heat exchange between the boiler fire tubes and the food to be fried is much improved. Also, the fact that the pump is disposed inside the oil tank makes superfluous piping unnecessary.
If the oil circuit is divided into two stages, i.e., upper and lower stages, and the pump is disposed in the lower stage of the circuit, the entire device may be built in a compact structure.
By providing a filter midway through the oil circuit, it is possible to remove scum from the frying oil with ease.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
FIG. 1 is a perspective view of the entire apparatus of the present invention;
FIG. 2 is a perspective view of the entire apparatus with the conveyor frame in a raised position.
FIG. 3 is a cut-away illustration of the conveyor structure of the present invention.
FIG. 4 is a perspective view of the pump impeller.
FIG. 5 is a transverse sectional view showing the construction of the frying oil heating unit;
FIG. 6 is a transverse sectional view of the frying oil circuit, showing its structure, of said example.
FIG. 7 is a diagram showing the distribution of the frying oil flow rates in the oil circuit;
FIG. 8 is a transverse sectional view of the filter unit, showing its construction; and
FIG. 9 is an illustration of the structure of the essential part of a food frying device according to the prior art.
DETAILED DESCRIPTION OF THE INVENTION
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
FIGS. 1 to 8, inclusive, of the accompanying drawings illustrate an example of the embodiment of the present invention.
FIG. 1 is a perspective view of the entire apparatus, wherein numeral (1) indicates the conveyor frame, element (2) the frying oil heating unit, element (3) an oil hydraulic cylinder for lifting up the conveyor frame, element (4) a carrying net conveyor for conveying food to be fried through the frying oil, and element (5) a paper filter carrying net conveyor for conveying the filter paper for removal of scum from frying oil.
FIG. 2 is a perspective view of the entire apparatus with the conveyor frame (1) being raised by means of four oil hydraulic cylinders (3).
FIG. 3 shows the construction of the essential part of the frying device. The carrying net conveyor (4) and a submerging net conveyor (6) are fitted on the conveyor frame, and pieces of food to be fried (7) are carried through the oil tank by a combination of these two net conveyors (4) and (6).
The numeral (8) indicates a partition plate whereby the inside of the oil tank is divided into two stages, the upper and lower, and beneath the left end of said partition plate (8), there is disposed a vane pump (9). By virture of the action of said vane pump (9), oil heated by the frying oil heating unit (2) flows from the lower stage of the oil tank, through an oil channel (10), into a frying pool (11) above the partition plate (8) by an entrance at the right end of said partition plate (8), thus making it possible to keep the frying oil circulating in the oil tank.
At the left end of the partition plate (8) and on the upper left side of the vane pump (9), there is provided a paper filter carrying net conveyor (5) in such a manner that it crosses the path of the frying oil flow (at a right angle to the picture plane in FIG. 3), whereby the paper filter (12) is permitted to travel at a slow speed. With this equipment, it is possible to filter the frying oil, thereby removing scum, dregs, or the like, from the circulating oil.
Fire tubes (13) arranged in three tiers in the frying oil heating unit (2) are heated by gas burners, as will be described later on.
The foregoing is an outline of the construction of the present invention. Pieces of food to be fried (7) are thrown into the oil from an opening (14), are carried through frying oil, guided by the carrying net conveyor (4) and the submerging net conveyor (6), for a predetermined time, and are discharged from an opening (15) for removing the fried food.
In order to obtain higher efficiency in heat exchange between oil frying oil and food to be fried, the flow rate of frying oil may be so adjusted as to be slightly higher than the travelling speed of the conveyors (4) and (6), by regulating the revolutions of the vane pump (9).
The conveyors (4) and (6), and the partition plate (8) are installed on the conveyor frame (1). The conveyor frame (1) can be raised and held in a level condition by oil hydraulic cylinders (3). This serves to facilitate cleaning of the inside of the oil tank, while affording convenience in many other aspects, such as maintenance.
Although a vane pump (9) is employed in this example of the present invention, there may be employed a pump having an impeller with many broad blades (17) (what is commonly referred to as "sirocco fan"), as illustrated in FIG. 4, instead of a vane pump.
Further, with respect to the frying oil heating unit (2), the heating of frying oil may be done by an open fire.
FIG. 5 is a transverse sectional view of the frying oil heating unit (2), showing its construction. The gas burner (20) and fire tubes (13a), (13b) and (13c) are disposed in plurality along the course of flow of frying oil (25) (at a right angle to the picture plane in FIG. 5). The fire tubes of the present invention are disposed in three tiers. On the side where the gas burner (20) is disposed (the right-hand side in the picture), there is provided a partition plate (21) between the bottom tier fire tube (13a) and the middle tier fire tube 13(b). On the opposite side of the burner (20), there is provided a partition plate (22) as a partition between the middle tier fire tube (13b) and the top tire fire tube (13c). By such provision, heat fumes generated by the burner (20) can be conveyed from the bottom tire fire tube (13a) to the middle tier fire tube (13b) and further to the top tier fire tube (13c), thereby ensuring an efficient heat exchange between the gas burner (20) and frying oil (25). The numerals (23) and (26) both indicating an exhaust port.
FIG. 6 is a transverse sectional view of the frying oil channel (10), showing its structure. On the bottom of said frying oil channel (10), there are provided a plurality of ridges (27) disposed in parallel with the flow of the frying oil. Accordingly, as an illustration of the distribution of the frying oil flow rates in the frying oil channel (10), as shown in FIG. 7, the flow rate of frying oil is slow near the wall and becomes quicker and quicker farther away from the wall. In the illustration, the letter (x) indicates the flow rate of the frying oil passing over the top of the ridge (27), and the letter (y) indicates the frying oil passing through the groove between the ridges (27). This means that there arises in the frying oil channels (10) frying oil flowing at several different flow rates. Therefore, the frying oil is, so to speak, stirred up, thereby making the temperature of the frying oil uniform.
By the use of the ridges (27), the frying oil channel (10) is, in substance, narrowed and the speed at which the frying oil is conveyed is increased. This means that it is possible to reduce wasteful radiation of heat.
Still further, as it is possible to virtually decrease the amount of frying oil in the oil tank, the ratio of fresh frying oil, when replenishing oil consumed in the course of manufacturing fried food, will become higher. Thus, the rate of replenishment of the frying oil is higher when the entire amount of frying oil in the oil tank is smaller than when it is larger, producing the effect of preventing early deterioration of the frying oil.
The number of the aforesaid ridges (27) may be chosen as desired, while, as for the length of the ridges (27), there is the freedom of choice, too. They may be provided over the whole length of the frying oil channel (10), or may be provided along only a part or parts of it. Also, the section of the ridges (27) may have other shapes than that shown in the drawings. Any shape, for example, a wavelike form, may be chosen as desired.
FIG. 8 is a transverse sectional view of the filter unit, showing its construction. The paper filter (12), mounted on the paper filter carrying net conveyor (5), travels across the flow of frying oil (25). The numeral (30) indicates a roll of filter paper. By virtue of this equipment, it is possible to continuously scum, dregs, or the like, from the frying oil.
The present invention, with the construction as described in the foregoing paragraphs, produces the following effects.
In the first place, by keeping the frying oil circulating in the oil tank, it is possible to obtain a uniform temperature in the frying oil and, therefore, to produce uniformly fried food, Also, since heat exchange between fire tubes and food to be fried is promoted, the time required for frying is shortened.
Since the oil tank is divided into two stages, i.e., the upper and lower stages, the device has a compact structure.
Since the pump is disposed inside the oil tank, there is no redundant piping and so the construction is simplified.
Since it is possible to continuously remove scum from the frying oil by the filter, early deterioration of oil can be prevented.
Because of the use of the partition plates provided inside the frying oil heating unit, fume heat generated by the gas burner is conveyed to all the fire tubes in three tiers, and the efficiency of the heat exchange to the frying oil is improved.
The use of ridges in the frying oil channel serves, together with the aforementioned circulation of frying oil, to make the oil temperature uniform, and as it further serves to reduce, in substance, the amount of frying oil, the rate of replenishment of fresh frying oil can be made higher, leading to the prevention of early deterioration of the frying oil.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. | An automatic continuous food frying device comprising an oil tank adapted to be filled with a frying oil, a heating means for heating said frying oil, and a means for conveying food in a submerged state in the frying oil, wherein there is provided a pump in the oil tank so that the frying oil may be continuously circulated in the tank. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is the United States national phase under 35 U.S.C. §371 of PCT International Patent Application No. PCT/EP2008/008142, filed on Sep. 25, 2008.
BACKGROUND OF THE INVENTION
Field of the Invention
Embodiments of the invention concern a method for configuring an application.
It is common practice to download installation files to install an application via a data connection and to store them on a local computer system. After downloading and local storage of one or more installation files, the respective application can be installed on the local computer system.
A download of the respective installation file or the application in the form of an executable file is implemented with a data connection which is established with an appropriate server where said files are stored. The data connection is usually established via a browser of the local computer system or via access to enabled network drives.
Following the successful installation of the application, usually a configuration of the application is required. In the case of a client-server or Web application, for instance, a URL (Uniform Resource Locator) is entered for an associated server with which the Web application will work while in operation. In addition, it might be necessary to enter or transfer login credentials allowing automatic authorization of the Web application at an associated server.
Such an input of configuration data after local installation of the application is considered impractical in many cases. Duplications could result when inputting the authorization data, for instance, if a login is already required to download the installation files and then has to be re-entered with the related login information for the already installed application.
Another example involves downloading installation files via a network connection using an enabled network drive, where access requires authorization but the authorization data are transmitted automatically by the local computer system. This is the case, for instance, within company intranet networks, where a corresponding network drive can be enabled only with stored authorization data and usually automatically, i.e., without requiring an access-dependent input. In addition, companies usually have automatic access to company databases, or corporate directories, which assign each employee individual communication data as well as server configurations, enabled network drives, etc. on a call-up basis. For such company networks, any configuration following installation is time-consuming and considered impractical by companies in which updates and configuration measures are normally processed automatically without any action by the operator of the local computer system.
BRIEF SUMMARY OF THE INVENTION
It would be desirable to simplify the configuration of an application obtained via download and installed.
One method for configuring an application consisting of a server-side portion of the application, installed on a server computer system, and a client-side portion of the application, which is to be installed and configured on a client computer system, involves the following procedural steps.
After the client computer system accesses a web server assigned to the server-side portion of the application, a download page is generated by the web server. The server-side portion of the application, in its most generic form, corresponds in this case to an installation of the application on a server, which can already be set up for certain needs of a target group at which the download is directed. The client-side portion of the application corresponds to the portion of the application to be installed on the client-side computer system. The client-side and server-side portions of the application may, in general form, be identical; however, especially in the case of so-called Web-applications, often installations are used in which a server-side portion of the application works together with a client-side portion of the application, wherein the client-side portion has different tasks and functions which are shared.
According to the invention, the download page generated by the web server application contains configuration data to configure the client-side portion of the application and is loaded into the client computer system in a browser. For example, the download page is designed in the known HTML (Hypertext Markup Language) format and contains the configuration data in HTML Source Code.
In the next step, the client-side portion of the application is transferred and/or downloaded. After a successful and complete download of the installation files and/or the executable files of the client-side portion of the application, the application is installed on the client computer system.
In a subsequent step, the client-side portion of the application is configured, and this configuration must occur based on the invented means and not via user input, but automatically, i.e., using configuration data from the download page.
With the presented method of the invention, initial configuration of the application to be installed on the client computer system is unnecessary. This is advantageous since the user does not have to deal with inputs which often are considered time-consuming. Also, such manual inputs can be flawed. The invention thus contributes to a configuration with fewer mistakes.
In one advantageous embodiment of the invention, it is possible to store and/or install an additional configuration component on the client computer system and to start it after the successful installation of the client-side portion of the application. For this purpose, a local client-server connection is established between the configuration component acting as server and the browser acting as client, wherein the configuration data of the download page which has been loaded to the browser are transmitted to the configuration component via the local client-server connection. Such a local client-server connection is especially advantageous when the security settings of the browser prohibit direct acceptance of the configuration data from a remote location, i.e., the storage location of the web server application on the server computer system. Such a connection between a local server and a local client is also called a “local host” connection in the industry. In this embodiment, the client-side portion of the application is configured by said configuration component using the configuration data from the download page.
Another advantageous embodiment of the invention provides for the deletion of the configuration component after successful installation and configuration of the application, in order to free up resources on the client computer system.
According to another embodiment of the invention, the download page is designed such that it contains a control element, e.g., a selectable link to the storage location of the web server, as well as another control element, e.g., a button whose activation triggers the configuration according to the invention.
In an alternative embodiment, a sequence control consisting of download, installation, and configuration may also be controlled by a script.
Configuration of the client-side portion of the application is triggered, for instance, by entering the configuration data in a registration database (“registry”) or in one or more configuration files.
According to another advantageous embodiment of the invention, access by the client computer system to the web server application is granted only after appropriate authentication of a user on the client computer system. Such authentication usually requires a login consisting of a user ID and corresponding password. As an alternative, authentication can also be handled by a transfer of authorization data as part of establishing a data connection to the web server using authorization data stored in the client computer system. Such authorization data will be automatically transmitted, for instance, when a network drive is accessed which is only accessible to certain users or user groups. According to the invention, the mentioned authorization data can be used to identify an individual user and transmit associated processed configuration data to configure the client-side portion of the application. If the configuration data consist only of a user name and associated password, these can be identical with authorization data also consisting of user ID and password.
An example with additional advantages and embodiments of the invention is illustrated below and explained in greater detail based on the drawings.
BRIEF DESCRIPTION OF THE DRAWING
The single FIG. 1 shows a simplified diagram to explain the interaction of individual components according to an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
At this point, the industry knows of applications which are run on a server computer system. Such web applications receive transmitted request data from a client computer system, process them and provide corresponding result data to the client computer system. The request data, for instance, will be input in a web page provided by the server computer system and loaded into a client system in a browser. The request data are transmitted to the server computer system and are processed there. As a result of this processing, corresponding result data will be calculated on the server computer system and transmitted to the client computer system. An example for such a web application is a service that receives one or more search terms as request data and returns web pages as result data containing one or a combination of several search terms.
The industry currently uses web applications or web browser-based applications in which an application executed on a server computer system cooperates with an application executed on the client computer system. In the language of the industry this involves a server-side portion of the application and a client-side portion of the application. An example for this would be an application by Google, Inc., CA, USA called “Google Earth,” (a trademark of Google, Inc.) which requires previous installation of the client-side portion of the application before it can be operated. The client-side portion of the application controls a moving presentation of geographical maps and cooperates with a server-side portion so that map data requested by the client-side portion are assigned and transmitted by the server-side portion. With this type of functional distribution between a server computer system and a client computer system, it is possible to achieve a far more efficient presentation, allowing smoothly flowing display of the maps despite the lack of complete storage of the map data on the client computer system.
The invention presented here is, however, not limited to a different design of the server-side and client-side portions of the application for the purpose of job sharing. The invention also comprises applications where the server-side portion differs from the client-side portion only in that the installed client-side portion has been configured or customized with certain configuration data. In other words, the invented method also allows the installation and configuration of applications where a server-side portion of the application is installed on a server computer system. This server-side portion of the application must be installed on a client computer system with the means provided by the invention or at least nearly identical means, wherein appropriate configuration of the client-side portion must be provided after installation.
The application installed on the client computer system does not necessarily have to cooperate as a client server application with a server-side portion while operating. The means of the invention can also be used to download and configure a “stand-alone” application.
In the following, three exemplary environments in which the invented method can be applied will be addressed.
In a first environment, an application from a software producer is offered for download via a browser. If a user on the client computer system decides to download the software, he must first create an account, by entering data about himself, for example, before he is given a link to an installation file for the application. These data comprise, for instance, a user name and a password. A combination of the selected username and the selected password lets the software producer authenticate the future user of the software. An account adds additional personal data to the username, e.g., payment data for the software. Such an account either has already been set up earlier by the user and linked to a username or is set up at the first download. Traditionally, the software producer is interested in offering his commercial software only to those users who have paid the agreed-upon price to download and use the software. After downloading and installing the software, the user may therefore be asked, the first time the application is started, to authenticate himself as rightful user of the software by entering his username and password. This repeated input of the user ID is considered inefficient, since it has already been required to download the software. With the invention as described below, however, it is possible to configure an application after the download and avoid having to re-input the user ID.
In a second environment, again, an application from a software producer is offered for download via a browser. This application, according to the second environment, is an application which requires the input of a user ID in order to be operated, because, for example, identification of the user by his username is required for communication with other users. For example, Skype Technologies SA, Luxembourg, offers an application called “Skype,” which allows quasi-realtime communication and data exchange via the Internet. (SKYPE is a trademark of Skype Technologies SA.). In it, a user is identified to other users by a username. When the application is started, an automatic login to a server is required to operate the application. For this purpose, an account is established for the respective username on the server, which requires previous registration and input of user data. For an existing account, the installed application logs in with automatic transmission of the user ID, i.e., username and password, to the server. For a user who wants to obtain the application via a download and then install it, it would be desirable to not have to reconfigure the installed application, i.e., re-input his user ID, since he has already created an account via a web form.
The third environment is based on an offer to download the application or its installation files via a network connection in a company intranet, where a corresponding network drive is enabled automatically with the stored authorization data, i.e., without requiring access-dependent input of the authorization data or user ID. In addition, companies usually have automatic access to company databases, or corporate directories, which assign each employee individual communication data as well as server configurations, enabled network drives, etc. on a call-up basis. For said company networks, a required configuration based on company database entries is desirable after installation of the application, allowing the user to configure the installed application on the local computer system without any additional input. Even if a configuration of an application that is installed for the first time is limited to input from the server assigned to the application, for a company with many employees this means a considerable amount of lost time. Automatic configuration is therefore also desirable in such an environment.
There are already state-of-the-art options for automatic configuration. One method used to date involves installation and initial configuration via a script-controlled process and using software distribution systems. A software distribution system is offered under the name “System Management System” or the abbreviation SMS by Microsoft Corporation, Redmond, Wash., USA. The use and operation of such software distribution systems do, however, involve some related expense and require appropriate programming of the installation onsite.
Also, so-called “discovery methods” have been used so far, wherein a server and a client are supposed to connect via broadcast mechanisms within a network. These methods are cumbersome even in small network architectures. In addition, mechanisms based on the discovery method alone cannot solve the problem of how specific configuration data can be made available.
Below, an embodiment of the invented method is explained using FIG. 1 .
FIG. 1 shows a server computer system SRV in which a server-side portion of the application has been installed in a storage area (not shown). This installed server-side portion of the application A will assume the role of server application in a future client-server-relationship between the server computer system SRV and a client computer system CLT. A component of the server-side portion of the application A comprises components of the client-side portion of the application IX, which are transmitted to the client computer system via download and installed there.
Depending on download capacity needs, the expert implementing the invented method chooses whether the server-side portion of the application A uninstalls the client-side portion of the application IX, i.e. keeps it in the form of installation data, or whether the files needed on the client computer system are already installed on the server side, i.e., are unpacked there, so they can be transmitted to the client computer system CLT. In the latter case, the application X described later, which is installed on the client system, resembles for the most part the client-side portion of application IX.
On one hand, referring to or downloading the client-side portion of application IX from the server computer system SRV means referring to files from the client-side portion of the application IX installed or pre-installed on the server side, and on the other hand it means, as an alternative, referring to installation files to be installed from the client-side portion of application IX.
In an alternative embodiment of the invention, a configuration component C′ can be part of the client-side portion of the application IX, as shown, or (not shown) it can be assigned to the client-side portion of the application IX. This configuration component C′ is usually not considered necessary for the embodiment of the invention.
Another component of the server-side portion of the application A comprises a web server application WS.
The dashed-line border and the symbolic representation of the application A portion installed on the server-side already indicates that the organization of the web server application WS and the client-side portion of the application IX is left up to the expert. In some instances, integration of the web server application WS into the client-side portion of the application IX may also be selected.
A user on the client computer system CLT now accesses the web server application WS. This is symbolized by an arrow labeled 1. The user has also received a link or URL which, when input into a browser BRW, addresses the server application WS. Optionally, login credentials are authenticated. The web server application WS now generates a webpage WBP which is shown to the user in the browser BRW as a download page WBP with corresponding user instructions (not shown). The download page loaded in the browser of the client-side computer system also contains configuration data for configuring the client-side portion of the application, which are transmitted invisibly in the source code of the HTML page WBP. In this context, the configuration data are taken from the user's account information or other user-specific configuration data stored on the server computer system SRV or another server (not shown).
Another component of the download page WBP are two control elements LNK, CRT which will be explained in detail below. A first control element LNK constitutes a selectable link LNK to a download of the desired application, more precisely the client-side portion of the application IX. The link therefore refers to the storage location of the client-side portion of the application IX. The user can trigger a download and storage or installation of the client-side portion of the application IX by activating the link LNK, e.g. with a mouse click.
An installed client-side portion of the application on the client computer system is illustrated in FIG. 1 with the installed application X and the installed configuration component C. The installation occurs in an area (not shown) of the storage memory on the client computer system which is provided for installing applications.
An installation routine for installing the application X and the installed configuration component C can include an automatic start of the executable configuration component after successful installation of the application X and the configuration component C.
A second control element CRT of the download page WBP is designed, for instance, as a key or button which, when pressed by the user, can trigger a configuration of the already successfully installed application X. Preferably, the second control element is presented as configuration key CRT or marked with the comment “One touch post install configuration”, for instance. In this way, it is possible to achieve installation and initial configuration in an advantageous way using the method described below and starting from the same download page WBP.
As an alternative to an automatic start of the configuration component C, after the successful installation, a start can be accomplished by activating the configuration key CRT.
After successful installation and automatic start of the configuration component C, pressing the configuration key CRT by the user initiates automatic configuration of the application X using configuration data transmitted in the source code of the HTML page WBP.
For this purpose, in one embodiment of the invention, a local client-server connection is established between the configuration component C acting as server and the browser BRW acting as client, wherein the configuration data from the download page loaded into the browser via the local client-server connection, e.g., via an HTTP or HTTP/S connection using the HTTP functions HTTP-GET or HTTP-POST, are transmitted to the configuration component.
Such a local client-server connection or local host connection is especially recommended when the security settings of the browser prohibit direct acceptance of the configuration data from a remote location, i.e., the storage location of the web server application WS.
After receiving the configuration data, the configuration component C transmits the configuration data to a storage location set aside for the application X to use for reading access, e.g., the registry or one or more configuration files.
The use of the configuration component C is unnecessary when the browser's security settings allow remote access within a company's intranet. In this case, the client-side portion of the application X is configured with direct use of configuration data from the download page which can be read via the browser BRW.
In an alternative embodiment of the invention, the actions triggered by the two control elements LNK, CRT, i.e., download including installation and initial configuration, are executed automatically in sequence so that the user simply has to activate one control element CRT on the download page.
One example of an application area for this invention are business web applications which are installed on a server in the customer's network. The proposed One Touch Configuration method simplifies the initial configuration of the application that is to be installed and makes manual input after the installation unnecessary.
The method is easier to implement than other comparable methods. User-specific data can be updated generically via the server-side portion of the application A and then routed via the browser on the client computer system CLT to the installed application X.
The invented method can also be used to obtain applications from the Internet, wherein a customer has an account with a service provider. The customer uses his customer login to log into the web pages of the company. The company knows the customer's account information, which applications the customer has bought and can make available additional complementary downloads including a license key for each one. The license key can then simply be transmitted to the installed application using the presented method. | The invention relates to a method for automatically configuring an application after downloading the same via a website. An example of an area of application of the present invention is enterprise web applications that are installed on a server in a customer network. The proposed “one-touch configuration” method simplifies the initial configuration of the application to be installed, and makes manual entries after installation unnecessary. The method according to the invention is further applicable to obtaining applications from the Internet, wherein a customer has an account with a provider. The customer logs in using the customer login thereof at the website of the company. The company is aware of which applications the customer has purchased, by means of the customer account information, and can proved corresponding supplementary downloads, including a licensing key. The licensing key can then be transmitted to the installed application in a simple manner using the method presented. | 6 |
CROSS-REFERENCES TO RELATED APPLICATIONS
This patent application relates to a previously filed and still pending U.S. non-provisional patent application filed by the same inventors herein. It has the Ser. No. 13/901,507, was filed on May 23, 2013, and has the title of “Manual Transfer Vest”. Since the inventions in both applications have structural similarity to one another and common subject matter, the applicants herein respectfully request a grant of domestic priority for this current patent application herein with improvements based upon their previously filed U.S. Ser. No. 13/901,507.
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to patient transfer systems and, particularly to a manual patient transfer system in the form of a vest comprising several multi-functional patient assistive transfer features, which compensates at least in part for fatigue, pain, loss of strength, loss of mobility, and lack of energy in the daily life of moderately mobility-challenged patients or individuals who are still ambulatory but have difficulty in rising from a sitting position into a standing position. However, the present invention can also be used for other patient transfers, such as, but not limited to, lateral bed transfers and repositioning maneuvers.
Description of the Related Art
According to the CDC, each year in the United States one in three adults age 65 and older suffers a fall. The death rate from falls among older U.S. men and women has risen sharply, and falls are now their leading cause of early death. While not always being an immediate cause of death, falls can cause moderate to severe injuries, such as hip fractures and traumatic brain injuries, which accelerate death. Medical journals document that nursing homes with one hundred beds may annually experience as many as 100-200 patient falls. Other causes for nursing homes falls can include “transfer” difficulty (for example moving a patient from a bed to a chair), poor foot care, poor fitting shoes and improper or incorrect use of walking aids. In addition, medical journals and other publicly available medical information further documents that for the year 2000 the total annual estimated cost in the U.S. relating to nonfatal, fall-related injuries was at least $16 billion. For hip fractures alone, the average cost per patient during the first year of occurrence is at least $25,000, with a lifetime cost of sustaining a hip fracture approximately $81,300 (of which approximately half was spent on nursing home care). Every year, falls among older people cost the nation more than $20.2 billion in direct medical costs. Medicare costs for hip fractures are almost $3 billion annually. By 2020, the total annual cost of these injuries is expected to reach $32.4 billion.
In addition, the high physical demands associated with the handling and moving of patients is probably the largest contributing factor to high rates of musculoskeletal disorders (MSD) among practicing nurses and caregivers. Work-related MSD, such as back and shoulder injuries, persist as the leading and most costly U.S. occupational health problem due to the cumulative effect of repeated manual patient-handling activities as well as patient transfers done in extreme static awkward postures. The present invention manual transfer vest is designed and constructed to assist practicing nurses and caregivers in handling and moving patients (obese and non-obese) without injury to themselves or to the patient, including patient fall prevention, with use contemplated by professionals and staff in hospitals, nursing homes, and assisted living facilities, but not limited thereto, as well as by people at home taking care of a family member.
In their observations as Registered Nurses, the inventors herein have found that in addition to obese populations, the elderly and disabled are in great need of transfer assistive devices that are better focused on transferring the patient with the highest level of comfort and safety possible, and also provide benefit to the caregiver by reducing the risk of caregiver MSD. Without an assistive device, one or more people are needed to lift an individual into a standing position, typically using the arms. Particularly for elderly populations, as well as other populations who require assistance with ambulation, repeated pulling on the arms can be uncomfortable for individuals attempting to stand, and may lead to arm soreness and other injuries. Also, the disabled often do not have the muscular-skeletal capability or coordination to assist a caregiver during attempts to move them, which places more of a physical burden on the caregiver. The present invention transfer assistive device herein, in the form of a vest, is a non-mechanical lift and patient repositioning device intended to reduce the risk and injuries associated with the populations mentioned hereinabove. The main objectives of the present invention are to promote patient safety, dignity, mobility and independence, which in turn will enhance their quality of life. The present invention has been developed with the safety, comfort and well-being of the patient and caregiver in mind.
Use of the present invention manual transfer vest is not only contemplated for people attempting to rise from a seated position into a standing position when a risk of falling is greatly increased, but also for moderately mobility-challenged patients or individuals who are still ambulatory but in need of assistance while walking to prevent a fall. The front lifting components in the present invention vest assist a person standing in front of a seated patient to slowly, steadily, and in a controlled manner pull the seated patient toward them, until the seated patient has reached a standing position, with a combination of front and back lifting components being used by one or two caregivers to stabilize an ambulatory patient from one or both sides while walking occurs. Other patient transfers can also be assisted by use of the present invention, such as but not limited to lateral bed transfers and repositioning maneuvers. Many transfer assistive devices for patients and others are known, however, each has undesirable limitations which are overcome by the present invention. The present invention is intended to be worn continuously by patients while movement and mobility challenges exist, even while sleeping, and overcomes all disadvantages of the known prior art.
BRIEF SUMMARY OF THE INVENTION
The primary objective of this invention is to provide a manual patient transfer assistive device in the form of a vest that is able to transfer an elderly, disabled, or obese patient with the highest level of comfort and safety possible to the patient and the person or persons aiding the patient. It is also an objective of this invention to provide a manual patient transfer assistive device that allows transfer of most elderly, disabled, and obese patients by one person. A further objective of this invention is to provide a manual patient transfer assistive device easily capable of achieving more than one patient transfer function. Another objective of this invention is to provide a manual patient transfer assistive device that allows patient transfers to be done in extreme static awkward postures without injury to the patient or the person aiding the patient. It is a further objective of this invention to provide a manual patient transfer assistive device that consists of well-designed, strong, and durable construction. Furthermore, it is an objective of this invention is to provide a manual patient transfer assistive device with visible and/or concealed size adjustment means to better accommodate patients during weight loss or gain. Another objective of this invention is to provide a manual patient transfer assistive device that is made of soft, lightweight, and easily washable materials. It is also an objective of this invention to provide a manual patient transfer assistive device that is comfortable when a patient is seated or sleeping, and does not get in the way during use of a commode. In addition, it is an objective of this invention to provide a manual patient transfer assistive device that facilitates patient independence while maintaining dignity, and may be made with or without a collar. A further objective of this invention is to provide a manual patient transfer assistive device for continuous or near continuous wear by moderately mobility-challenged patients, which has enhanced aesthetic appeal that does not visibly highlight a patient's movement challenges and instead makes patients feel as if they were wearing conventional and/or stylish clothing.
The present invention is a practical, efficient and well-designed manual multi-functional transfer device that is compact, lightweight, and easily capable of achieving more than one patient transfer function. It can be used with moderately mobility-challenged patients, and also used to promote a steady gait for safe patient ambulation. Using the manual transfer vest, one person usually can slowly, gently, evenly, steadily, and in a controlled manner, bring a seated patient into a standing position by pulling on the two lower vertically-extending and non-adjustable hand-grip lift components on the front of the vest that are closer to the abdominal/mid-section area of the person wearing the manual transfer vest. Should a patient be more difficult to maneuver, two people standing on opposite sides of a seated patient can bring the patient into a standing position by each simultaneously pulling on one of the upper front hand-grip lift components and on one of the upper back hand-grip lift components. Examples of other patient transfer activity that can be accomplished using the present invention include, but are not limited to, frontal transfers, lateral bed transfers, controlled stand-to-sit transitions, and repositioning maneuvers. The present invention manual transfer vest has flexible and durable material, which is also preferably lightweight for added patient comfort. However, for use in colder climates, the present invention manual transfer vest may comprise heavier material and/or more layers for added patient warmth. The preferred zippered or hook-and-loop front closure of the present invention manual transfer vest allows for easy on and off access while offering a comfortable fit. Raising a patient to a standing position using the hand-grip lift components of the present invention instead of patient arms, minimizes risk factors that can lead to patient or caregiver injury while increasing comfort for the patient wearing the manual transfer vest during needed transitions. To accommodate differing patient size, and provide a good fit for patient lifting and transfers, it is contemplated for the present invention manual transfer vest to be commercially available in more than one size, with visible and/or hidden additional size-adjustment means also present. Darts and indented side seams may also be used to provide a foot fit. The manual transfer vest of the present invention helps to minimize risk factors that can lead to patient or caregiver injury, while also offering style and warmth. Its functionality further enhances a patient's or individual's safety, mobility, and stability during ambulation and transfer, while also facilitating independence and maintaining dignity. No invention is known having the same structure and providing the same benefits as the present invention.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a front view of the most preferred embodiment of the present invention manual transfer vest with a zippered front closure and four frontal vertically-extending and non-adjustable hand-grip lift components, two of which are upper hand-grip lift components located in the clavicle/upper chest area adjacent to the shoulders of the person wearing the vest, and two of which are lower hand-grip lift components located lower on the vest closer to the abdominal/mid-section area of the person wearing the vest, with the vest also having reinforcement in key places for the hand-grip lift components to make certain that they remain strong during the lifting of heavy patients and patient lifting that occurs from static and sometimes awkward positions. FIG. 1 also shows two non-adjustable side hand-grip lift components each extending from a different one of the angled reinforcement straps laterally toward the vest's adjacent side seam, a side fit-adjustment area under each armhole, and soft material added around the neck and arm openings for added user comfort.
FIG. 2 is a rear view of the most preferred embodiment of the present invention showing two vertically-extending and non-adjustable upper hand-grip lift components located in the upper back area adjacent to the shoulders of the person wearing the manual patient transfer vest, with FIG. 2 also showing a centrally located and horizontally-extending non-adjustable back hand-grip lift component, the vest back material having a shorted length dimension than that of the front vest material, a side fit-adjustment area under each armhole, and soft material added around the neck and arm openings for added user comfort.
FIG. 3 is an interior view of the most preferred embodiment of the present invention showing its interior adjustment ties and reinforcement stitching.
FIG. 4 is a front view of a second preferred embodiment of the present invention manual transfer vest similar to that in FIG. 1 , with the exception of a slight repositioning of the lower front hand-grip lift component
FIG. 5 is a front view of a third preferred embodiment of the present invention manual transfer vest similar to that in FIG. 1 , with the exception of the addition of a collar, two vertical stitched darts adjacent to the central zippered closure, and inwardly-tapered side seams that enhance a form-fitted configuration for the vest when needed for improved caregiver lifting of the person wearing the present invention vest.
FIG. 6 is a front view of a fourth preferred embodiment of the present invention manual transfer vest with a zippered front closure and four frontal vertically-extending and non-adjustable hand-grip lift components, two of which are upper hand-grip lift components located in the clavicle/upper chest area adjacent to the shoulders of the person wearing the vest, with the other two of the vertically-extending and non-adjustable hand-grip lift components positioned between a horizontally-extending abdominal area strap that completely encircles the vest and a hip area strap below it that also completely encircles the vest, with the vest also having stitched reinforcement areas in key places for the hand-grip lift components to make certain that they remain strong during the lifting of heavy patients and patient lifting that occurs from static and sometimes awkward positions, and the remaining portions of the vertically-extending and horizontally-extending front straps not in use to create hand-grip lift components secured with reinforcement stitching.
FIG. 7 is a back view of a fourth preferred embodiment of the present invention manual transfer vest having two vertically-extending and non-adjustable back hand-grip lift components located in the upper back area adjacent to the shoulders of the person wearing the vest, with another horizontally-extending and non-adjustable back hand-grip lift component centrally positioned as a part of the horizontally-extending abdominal area strap that completely encircles the vest, with the vest also having stitched reinforcement areas in key places for the hand-grip lift components to make certain that they remain strong during the lifting of heavy patients and patient lifting that occurs from static and sometimes awkward positions, and the remaining portions of the vertically-extending and horizontally-extending front straps not in use to create hand-grip lift components secured with reinforcement stitching.
COMPONENT LIST
1 —most preferred embodiment of manual transfer vest
1 ′—second preferred embodiment of manual transfer vest
1 ″—third preferred embodiment of manual transfer vest
1 ′—fourth preferred embodiment of manual transfer vest
2 —front vest material
3 —front closure (not limited to a zipper, also could be heavy duty hook-and-loop material, or other sturdy closure means, also although front centering of the closure is preferred, it is not critical)
4 A—front portion of vertical lifting strap
4 B—back portion of vertical lifting strap
5 —angled reinforcement strap
6 —enlarged arm hole
7 —enlarged neck opening (for comfort and to prevent a sense of restriction around the neck should the vest material undergo any shift in position relative to patient during a transfer)
8 —padding
9 —stitched reinforcement area adjacent to hand-grip lift components 11
10 —front void space for user comfort while seated (also allows the two opposed edges in the lower portion of front vest material 2 on each side of the void space to be easily grasped by the user or a caregiver to pull down front vest material 2 during or after a patient transfer is made so that the lower front part of enlarged neck opening 7 does not become, or remain, uncomfortably positioned against the patient's neck)
11 —non-length-adjustable hand-grip lift component (created from a portion of lifting straps 4 A/ 4 B and other straps 19 , 21 , and 25 )
12 —attachment stitching (used for securing lifting straps 4 A/ 4 B and angled reinforcement strap 5 to front vest material 2 , securing lifting straps 4 A/ 4 B to front vest material 2 and back vest material 13 , and securing interior lining material 15 to the shortened lower portion of vest back 14 )
13 —back vest material
14 —shortened bottom edge of back vest material (prevents patient from sitting on vest and interference during use of a commode)
15 —interior lining material (secured to front vest material 2 and back vest material 13 )
16 —interior adjustment ties
17 —interior casing material (used to carry ties 16 and interior adjustment of front vest material 2 or back vest material 13 )
18 —side seam connecting front vest material 2 to back vest material 13 below armholes 6 (helps to secure some ties 16 and the lower ends of front lifting straps 4 A)
19 —horizontally-extending back strap
20 —side seam connecting front vest material 2 to back vest material 13
21 —front strap creating an angled hand-grip lift component 11
22 —collar
23 —inwardly-tapered side seam (enhances form-fitting configuration of front 2 vest material and back vest material 13 when needed for improved caregiver lifting of a person wearing the present invention vest)
24 —stitched dart (enhances form-fitting configuration of front 2 vest material and back vest material 13 when needed for improved caregiver lifting of a person wearing the present invention vest)
25 —horizontally-extending upper abdominal strap helping to create the lower front hand-grip lift components 11 , and also creating a central horizontally-extending central back hand-grip lift component 11
26 —horizontally-extending lower hip area strap helping to create the lower front hand-grip lift components 11
DETAILED DESCRIPTION OF THE INVENTION
The preferred embodiments of the present invention comprise a manual multi-functional patient transfer vest device (such as the most preferred vest 1 shown in FIGS. 1-3 ) which has patient interfaces, such as but not limited to, the non-adjustable hand-grip lift components 11 shown in FIGS. 1-3 , that can be employed for transferring moderately mobility-challenged patients (not shown). FIGS. 4, 5, and 6 / 7 respectively show second, third and fourth preferred embodiments ( 1 ′, 1 ″, and 1 ″) of the present invention. In the most preferred embodiment 1 , the multi-functional patient transfer vest device is a one-piece, sleeveless vest, with zippered front closure means, that fits snugly and covers the patient's upper back, mid-chest, and waist areas, but does not interfere with a patient's use of a commode. The front of the multi-functional patient transfer vest device 1 has four sturdy and durable vertically-extending, non-adjustable hand-grip lift components 11 , with two of the vertically-extending front hand-grip lift components 11 secured bilaterally to the front vest material 2 and extending across the clavicle/upper chest area or shoulder area of a patient wearing it, and the other two of the vertically-extending front hand-grip lift components 11 secured bilaterally to the front vest material 2 and extending across the abdominal/mid-section area of the patient. In addition, in the most preferred vest 1 , two more hand-grip lift components 11 are positioned bilaterally in the lower portion of the front vest material 2 , each extending in a generally downward direction away from the lower end of a different hand-grip lift component 11 in the patient's abdominal/mid-section area and toward the side of front vest material 2 . Furthermore, it is also preferred for the most preferred embodiment 1 of the present invention shown in FIGS. 1-3 to have at least two more hand-grip lift components 11 bilaterally on its back vest material 13 and at least extending across the upper back or shoulder area of the patient wearing it. To create sturdy and durable hand-grip lift components 11 and secure attachment to front vest material 2 and back vest material 13 , it is preferred for hand-grip lift components 11 to be made from one elongated lifting strap 4 (having a front portion 4 A contiguous with a back portion 4 B), and for lifting strap 4 to be secured at least on one end via stitched reinforcement area 9 to front vest material 2 or back vest material 13 , forming and strengthening the needed hand-grip lift components 11 . As shown in FIGS. 1-3 , reinforcing attachment stitching 12 is placed on front angled reinforcement straps 5 , and most areas of vertical lifting front straps 4 A, vertical lifting back straps 4 B, and horizontally-extending back strap 19 where hand-grip lift components 11 are not present.
Manual transfer vest 1 preferably comprises soft, durable, and flexible material to provide patient comfort, with stronger material used in larger sizes intended for heavier patients. The padding 8 surrounding armholes 6 and neck opening 7 in FIGS. 1-4 also contribute to patient comfort, and is a preferred component of the present invention, although not critical. In addition, the outer fabric of manual transfer vest 1 must also be sufficiently strong to support the patient without premature failure during repeat patient lifting and other transfers. Thus, it is also preferred embodiments ( 1 , 1 ′, 1 ″, 1 ″, and other) of the present invention manual transfer vest to have an interior lining 15 , which can be made of materials that provide durability and enhanced patient comfort when the present invention is used. The present invention lining 15 may also be made of materials that provide additional warmth when the present invention is used in colder surroundings. In addition, and although not critical, it is preferred for the materials ( 2 , 4 , 5 , 8 , 13 , and 15 - 17 ) used for preferred embodiments of the present invention manual transfer vest ( 1 , 1 ′, 1 ″, 1 ″, and other) to be machine washable and machine dryable. The hand-grip lift components 11 attached to manual transfer vest 1 can be made from the same material ( 2 and 13 ) used to construct its front and back exterior surfaces. In the alternative, hand-grip lift components 11 may be made from different strong and durable strap 4 material as long as it is not stretchable or overly firm to diminish caregiver hand comfort.
While not limited thereto, one preferred material used for the outer/exterior fabric ( 2 and 13 ) of manual transfer vest 1 is Rip-Stop Nylon, which is water-resistant, woven, and lightweight, with an imbedded grid designed to stop rips or tears from spidering and getting larger. Rip-Stop Nylon is also machine-washable in warm water and can be tumble dried on medium heat, with a cool iron used as required. Another material contemplated as an outer fabric ( 2 and 13 ) for manual transfer vest 1 is Cordura Nylon Fabric, which has a well-established reputation for toughness and durability. Cordura Nylon Fabric is also waterproof, abrasion-resistant, rot-resistant, and mildew-resistant when a clear Polyurethane coating is added. It is also known for its durability and resistance to tears and scuffs. In addition, other materials are contemplated for the outer/exterior fabric ( 2 and 13 ) of manual transfer vest 1 , including mesh fabrics.
It is also preferable for the interior lining material 15 for manual transfer vest 1 to be durable, soft, and machine washable. Other preferred choices for interior lining material 15 are that it not wear out easily and that it comprise natural textiles, such as cotton, wool or silk, or from synthetic fibers such as rayon or nylon. It is also preferred for interior lining material 15 to offer patient comfort and breathability, as well as be waterproof, shrink-resistant, and heat-resistant. Shrink-resistance is important so that manual transfer vest 1 continues to provide a snug fit around a patient 16 , without binding. Lifting strap 4 (including front portion 4 A and back portion 4 B) also preferably has one-piece construction, a maximum width dimension of approximately two-inches. The thread used as stitching 12 to attach lifting strap 4 to front and back vest material ( 2 , 13 ) may be a durable upholstery thread made from 100% polyester with a heat-resistant finish or a polyester blend. It is also preferred for manual transfer vest 1 to have a zipper closure 3 made from 100% polyester and a durable plastic that is strong and weatherproof, although other durable closures can be used, including but not limited to one or more hook-and-loop closures, oversized buttons, heavy-duty grippers, or heavy-duty snaps. Although not shown, reinforcement material may be positioned under stitched reinforcement areas 9 between interior lining material 15 and front vest material 2 or back vest material 13 to provide an additional layer of outer vest material ( 2 , 13 ), or a layer of another material or fabric capable of strengthening the attachment of stitched reinforcement areas 9 . Also, more than one layer of reinforcement material made from the same or different materials may be used for strengthening any one, or all, of the stitched reinforcement areas 9 .
The design and size of manual transfer vest 1 should allow easy-on and easy-off handling, while also providing a comfortable fit on the person requiring transfer so that each transfer made is smooth and conducted with enhanced patent comfort. The most preferred embodiment of the present invention manual transfer vest 1 is designed without gender preference, and is equally usable by both men and women, without any modification. Manual transfer vest 1 may also be made in solid colors to complement patient clothing, or from materials ( 2 , 4 , 5 , 8 , 13 , or 15 - 17 ) that display a mixture of colors, textures, and/or designs for variety and/or enhanced aesthetic appeal, and although not shown, as a source of user convenience manual transfer vest 1 may comprise one or more exterior or interior pockets in various locations. Due to the need for a comfortable fit, as mentioned above, it is contemplated for manual transfer vest 1 to be made in a variety of sizes, such as but not limited to small, medium, large, and extra-large. Interior adjustment ties 16 are also secured in interior casings 17 and used to make the present invention fit more snugly around a patient, if needed. Ties 16 could be important for patients expected to lose weight during a stay in a rehabilitative facility, so that one present invention vest ( 1 , 1 ′, 1 ″, 1 ″, and other) can be used the entire rehabilitation with minor adjustments quickly made when periodically needed. Preferred dimensions for a small manual transfer vest 1 include a shoulder-to-shoulder dimension of approximately fourteen inches, a chest dimension of approximately nineteen inches, a hip dimension of approximately twenty inches, and a length dimension of approximately twenty-five inches. Other sizes can also be made proportionally larger or smaller, according to need. As considered appropriate, large, extra large, and even greater sizes of manual transfer vest 1 could have hand-grip lift components 11 with a larger width dimension than is used for small and medium sizes, and the number, placement, size, and/or stitching pattern used for stitched reinforcement areas 9 in any size of manual transfer vest 1 could also be different from that illustrated in FIGS. 1-4 herein.
FIGS. 1-3 show the most preferred embodiment of the present invention manual transfer vest 1 . FIG. 1 is a front view of manual transfer vest 1 with a zippered front closure 3 and four frontal and substantially vertically-extending (and non-adjustable) hand-grip lift components 11 , two of which are upper hand-grip lift components 11 located in the clavicle/upper chest area adjacent to the shoulders of the person 16 wearing manual transfer vest 1 , and two of which are lower hand-grip lift components 11 located lower on manual transfer vest 1 closer to the abdominal/mid-section area of the person 16 wearing it, with manual transfer vest 1 also having a stitched reinforcement area 9 adjacent to at least one end of each hand-grip lift component 11 to strengthen it and make certain that hand-grip lift components 11 maintain a secure attachment to the front portion 2 of manual transfer vest 1 during the lifting of heavy patients and when patient lifting occurs from static and sometimes awkward positions. Hand-grip lift components 11 should be sufficiently large for an adult caregiver to comfortably insert all four fingers through it, but not too large so that the caregiver cannot establish proper leverage to assist the type of patient transfer needed. FIG. 1 also shows one angled reinforcement strap 5 secured across the lower end of each of the front lift strap portions 4 A and connected to front vest material 2 and front lift strap portions 4 A with attachment stitching 12 . As can be further seen is FIG. 1 , each angled reinforcement strap 5 is stitched across a different front lift strap portion 4 A in a substantially perpendicular orientation thereto that provides enhanced strength for front lift strap portions 4 A during patient transfers, particularly a sit-to-stand patient transfer. Although only one reinforcement strap 5 is shown on each side of manual transfer vest 1 , it is considered to be within the scope of the present invention for more than one reinforcement strap 5 to be used, particularly in larger custom-ordered manual transfer vests 1 , but not limited thereto. Furthermore, the attachment stitching 12 shown in FIGS. 1-3 provides examples of where it might be placed to secure the parts of front lift strap portion 4 A not used as a hand-grip lift component 11 to front vest material 2 , to secure the parts of back lift strap portions 4 B not used as a hand-grip lift component 11 to back vest material 13 , to secure angled reinforcement straps 5 to front lift strap portions 4 A and front vest material 2 , to reinforce front closure 3 , and to attach interior casings 17 to interior lining material 15 and front vest material 2 or back vest materials 13 , should not be considered as limiting, and the number of stitches-per-inch, placement, nearness to any material edge, and the number of rows of attachment stitching 12 used in any location may be different from that shown. Since the lower portion of each front lift strap portion 4 A in FIG. 1 appears to curve downwardly and outwardly toward the sides of manual transfer vest 1 , the needed curvature can be formed into front lift strap portions 4 A during their manufacture, or provided as a result of making one or more darts or folds in front lift strap portions 4 A under the part of the angled reinforcement strap 5 that becomes stitched across it. Also, the lower portion of each front lift strap portion 4 A in FIG. 1 may be connected on its bottom end into the side seam 20 (see FIG. 3 ) connecting front vest material 2 to back vest material 13 . Furthermore, for comfort of the person wearing it during stand-to-sit patient transitions, FIG. 1 shows manual transfer vest 1 having preferred enlarged arm holes 6 , an enlarged neck opening 7 , and a front void space 10 positioned below zipper closure 3 . As shown in FIG. 1 , it is contemplated for front lift strap portions 4 A to have substantially symmetrical placement laterally on front vest material 2 for even and steady transitions of the patient wearing present invention vest ( 1 , 1 ′, and other). Also, as can be seen in FIG. 1 , the size of stitched reinforcement areas 9 do not have to be the same size, although they can be. Preferably, the stitched reinforcement areas 9 in present invention vests ( 1 , 1 ′, and other) are sized and shaped according to need, and as shown in FIG. 2 are not required to have a centrally positioned “x” configuration. Although the stitching 12 used to secure interior casings 17 to front vest material 2 is shown in FIG. 1 to be visible while viewing the most preferred embodiment 1 of the present invention, in other preferred embodiments of the present invention not shown herein, interior casings 17 may be secured only to interior lining material 15 , or to interior lining material 15 in combination with one or more layers of reinforcement material secured at least in part by one of the side seams 20 connecting front vest material 2 to back vest material 13 , or stitching 12 securing padding 8 to front vest material 2 , or stitching 12 securing horizontally-extending back strap 19 to back vest material 13 .
FIG. 2 is a rear view of the most preferred embodiment 1 of the present invention manual transfer vest showing two vertically-extending and non-adjustable upper hand-grip lift components 11 located in the upper back area adjacent to the shoulders of a person (not shown) wearing it, and the bottom edge 14 of vest back material 13 being shorter than front vest material 2 to assist the person wearing it during use of a commode so that prior removal of manual transfer vest 1 is not required. FIG. 2 also shows a horizontally-extending back strap 19 stitched to vest back material 13 and across the lower ends of back lift strap portions 4 B, which helps to strengthen the connection of the lower ends of back lift strap portions 4 B to vest back material 13 when transfer movement for a patient wearing manual transfer vest 1 involves the use of either one of the hand-grip lift components 11 located on the portion of back strap components 4 B associated with the upper back or shoulders of the person wearing it. Furthermore, in FIG. 2 , the back portion of enlarged neck opening 7 and armholes 6 are all shown with attached padding 8 for enhanced patient comfort. FIG. 2 also shows two stitched reinforcement areas 9 associated with horizontally-extending back strap 19 , between which not stitching 12 is placed, to create a horizontally-extending lower hand-grip lift component 11 . In contrast, stitching 12 is placed laterally from each stitched reinforcement area 9 associated with horizontally-extending back strap 19 , extending near the top and bottom edges of horizontally-extending back strap 19 to the side seam 20 (see FIG. 3 ) joining front vest material 2 to back vest material 13 . Although FIG. 2 shows the two stitched reinforcement areas 9 associated with horizontally-extending back strap 19 each having a large configuration and a central “x” configuration, FIG. 2 shows a smaller stitched reinforcement areas 9 without a central “x” configuration associated with each vertically-extending back strap 4 B. Thus, FIG. 2 shows reinforcement stitching 12 associated with all portions of vertically-extending back straps 4 B and horizontally-extending back strap 19 that do not create a hand-grip lift component 11 . In FIG. 2 , reinforcement stitching 12 is also shown for the interior casing 17 below each armhole 6 and the bottom edges of the front and back portions of present invention 1 . The configuration of all reinforcement stitching 12 on vest 1 is not limited to that shown in FIGS. 1 and 2 , and the number of stitches-per-inch, placement, nearness to any material edge, and the number of rows of attachment stitching 12 used in any location in preferred embodiments of the present invention may be different from that shown in FIGS. 1-4 .
FIG. 3 is an interior view of the most preferred embodiment 1 of the present invention showing its interior adjustment ties 16 , interior casings 17 , padding 8 around armholes 6 and neck opening 7 , stitched reinforcement areas 9 , reinforcement stitching 12 , and interior lining material 15 which is preferably soft. The relative sizes of padding 8 , interior adjustment ties 16 , interior casings 17 , and stitched reinforcement areas 9 may vary and are not considered as limited to that shown in FIG. 3 . Although not critical, a one-piece construction of each front-to-back-extending lift strap 4 ( 4 A and 4 B) from which three hand-grip lift components 11 are created is preferred, with one lift strap 4 extending up and over the right shoulder of the person wearing it, and the second lift strap 4 extending up and over the left shoulder of the person wearing vest 1 . FIG. 3 also shows the side seam 20 that connects front vest material 2 to back vest material 13 below armholes 6 , which further help to secure the lower ends of front lifting straps 4 A. Although only shown for side seams 20 , front closure 3 , and the bottom edges of front vest material 2 and back vest material 13 near the seam connecting it to lining material 15 , it is contemplated for reinforcement stitching 12 to be optionally used adjacent to any seam or edge of manual transfer vest 1 or other embodiment of the present invention, such as but not limited to armhole 6 seams where front vest material 2 and back vest material 13 are connected to lining material 15 , enlarged neck hole 7 seams where front vest material 2 and back vest material 13 are connected to lining material 15 and padding 8 . FIG. 3 also shows four areas where interior casings 17 and associated ties 16 are preferably located in the most preferred embodiment 1 of the present invention. One interior casing 17 and associated ties 16 are located under each armhole 6 , and the remaining two interior casings 17 and associated ties 16 are each located near a different side seam 20 near to the position where horizontally-extending back strap 19 is secured to back vest material 13 . In the upper interior casings 17 , which as attached to both the front and back portions of vest 1 , when the ties 16 are pulled and the lining material 15 attached to casings 17 becomes “gathered” to create a shorter length dimension for the casing 17 , and further when the two ties 16 adjacent to the casing 17 are assembled into a knot or bow to fix the length of casing 17 , preventing further lengthening of the casing 17 and attached lining material 15 as long as the ties 16 remain in the knot or bow configuration, a tighter fit of vest 1 under the armholes 6 is created for the person wearing vest 1 . A similar situation occurs for the lower interior casings 17 attached to the back portion of vest 1 , and when the ties 16 associated therewith are pulled and the lining material 15 attached to the lower casings 17 become “gathered” to create a shorter length dimension for one or both of the lower casings 17 , and further when the two ties 16 adjacent to each of the lower casings 17 are assembled into a knot or bow to temporarily fix the length of lower casing 17 , preventing further lengthening of the lower casing 17 and attached lining material 15 as long as the ties 16 remain in the knot or bow configuration, a tighter fit of vest 1 in the lower back portion of vest 1 is created for the person wearing it. When any of the ties 16 are released from the temporary knot or bow configuration (not shown), the associated lower interior casing 17 or upper interior casings 17 lengthen, returning to their original configuration. The ties 16 and casings 17 allow slight adjustments to the fit of vest 1 around the person wearing it to maximize patient transitions with minimum caregiver effort and maximum patient comfort.
FIGS. 4 and 5 respectively show second and third preferred embodiments ( 1 ′ and 1 ″) of the present invention FIG. 4 is a front view of a second preferred embodiment 1 ′ of the present invention manual transfer vest similar to that in FIG. 1 , with the exception of a slight repositioning of each of the lower front hand-grip lift components 11 . Instead of having the bottom end of each front lift strap portion 4 A having a different angled reinforcement strap 5 stitched across it in a substantially perpendicular orientation thereto, each front lift strap portion 4 A extends approximately to one of the angled reinforcement straps 5 , with a non-vertical front strap 21 creating an angled hand-grip lift component 11 while secured by an enlarged stitched reinforcement area 9 across the bottom end of front lift strap portion 4 A and the upper end of angled reinforcement strap 5 . The end of non-vertical front strap 21 not secured by the enlarged stitched reinforcement area 9 is preferably secured by the adjacent side seam 20 , or could be configured as an extension of the horizontally-extending back strap 19 . The angle of non-vertical front strap 21 and the size and configuration of the stitched reinforcement area 9 securing it to front vest material 2 can be different from that shown in FIG. 4 . As mentioned above, the angled reinforcement straps 5 is stitched across at lease a portion of the front lift strap portion 4 A, provide enhanced strength for front lift strap portions 4 A during patient transfers, particularly a sit-to-stand patient transfer. FIG. 5 is a front view of a third preferred embodiment 1 ″ of the present invention manual transfer vest similar to that in FIG. 1 , with the exception of the addition of a collar 22 , two vertical stitched darts 24 adjacent to the central zippered closure 3 , and inwardly-tapered side seams 23 that enhance a form-fitted configuration for front vest material 2 and back vest material 13 when needed for improved caregiver lifting of the person wearing the present invention vest.
FIGS. 6 and 7 show a fourth preferred embodiment 1 ′ of the present invention manual transfer vest. FIG. 6 is a front view of the fourth preferred embodiment of the present invention manual transfer vest with a zippered front closure 3 and four front vertically-extending and non-adjustable hand-grip lift components 11 , two of which are upper hand-grip lift components 11 located in the clavicle/upper chest area adjacent to the shoulders of the person wearing the vest, with the other two of the vertically-extending and non-adjustable hand-grip lift components 11 positioned between a horizontally-extending abdominal area strap 25 that completely encircles the vest material ( 2 / 13 ) and a hip area strap 26 below it that also completely encircles the vest material ( 2 / 13 ), with the vest 1 ′ also having stitched reinforcement areas 9 in key places for the hand-grip lift components 11 to make certain that they remain strong during the lifting of heavy patients and patient lifting that occurs from static and sometimes awkward positions. The remaining portions of the vertically-extending and horizontally-extending front straps 4 A not in use to create hand-grip lift components 11 secured with reinforcement stitching 12 . FIG. 7 is a back view of the fourth preferred embodiment 1 ′ of the present invention manual transfer vest having two vertically-extending and non-adjustable back hand-grip lift components 11 located in the upper back area adjacent to the shoulders of the person wearing the vest, with another horizontally-extending and non-adjustable back hand-grip lift component 11 centrally positioned as a part of the horizontally-extending abdominal area strap 25 that completely encircles the vest material ( 2 / 13 ), with the vest 1 ′ also having stitched reinforcement areas 9 in key places for the hand-grip lift components 11 to make certain that they remain strong during the lifting of heavy patients and patient lifting that occurs from static and sometimes awkward positions, and the remaining portions of the vertically-extending and horizontally-extending front straps not in use to create hand-grip lift components 11 secured with reinforcement stitching 12 .
To use the present invention, the patient (not shown) first dons manual transfer vest 1 and its front closure 3 (preferably the zipper closure 3 shown in FIG. 1 ) is secured so that manual transfer vest 1 completely enwraps the torso of the patient and provides a snug, but not too restrictive, fit around it. Should a slight tightening adjustment of vest 1 around the upper torso be needed, the interior ties beneath armholes 6 can be pulled and formed into a knot or bow to gather the associated casing 17 and its attached interior lining material 15 . In the alternative, should a slight tightening adjustment of vest 1 around the lower torso be needed, the lower interior ties 16 (one attached to the adjacent side seam 20 and the other secured inside the interior end of casing 17 ) can be used to gather the associated casing 17 and its attached interior lining material 15 with the tie 16 inside casing 17 being pulled and secured in a temporary knot or bow with the tie 16 secured to side seam 20 . The gathering can be released any time that the joined ties 16 are released from their knotted or bow configuration. Also, repeat adjustment of vest 1 with ties 16 can be conducted as many times as needed. For a frontal sit-to-stand transfer, patient 16 is in a sitting position. Using good body mechanics, the caregiver (not shown) would stand with knees slightly bent and leaning slightly forward in front of the patient wearing vest 1 . The caregiver would then place each hand within a different hand-grip lift component 11 on opposite sides of front closure 3 , and with ease and providing a controlled and gentle lift upward, the caregiver steadily assists the patient into a standing position. In contrast, for a lateral bed transfer, the caregiver would have the patient wearing vest 1 lie on his/her side and place both legs over the edge of the bed; then with ease and control, the caregiver would use the appropriate hand-grip lift component 11 (nearest the shoulder side down) to gently assist the patient to a sitting position. For a repositioning maneuver of a patient in bed, the caregiver would align and reposition the patient at the head of the bed by placing one hand in each of two different hand-grip lift components 11 and with ease and control, gently pull the patient wearing vest 1 upward until positioned at the head of the bed. The repositioning maneuver can also be accomplished with a two-person assist. In addition, for promoting a steady gate during safe ambulation while walking along side of a patient wearing vest 1 , the caregiver would place one hand through one hand-grip lift component 11 (front or back), which would steady the gait of the patient, thereby reducing the risk of him or her tripping or falling. This safe ambulation maneuver can also be accomplished by a two-person assist, with one person walking on each side of the patient wearing vest 1 and each holding onto one or more hand-grip lift component 11 (front or back).
While the written description of the invention herein is intended to enable one of ordinary skill to make and use its best mode, it should also be appreciated that the invention disclosure only provides examples of specific embodiments and methods, and examples, and many variations, combinations, and equivalents also exist which are not specifically mentioned. The present invention should therefore not be considered as limited to the above-described embodiments, methods, and examples, or the language in the accompanying Abstract, but instead encompassing all embodiments and methods within the scope and spirit of the invention, as defined in the accompanying claims. | A manual transfer vest which aids in compensating for fatigue, pain, loss of strength, mobility, and energy in the daily life of patients and/or individuals/caregivers assisting them. It comprises soft, lightweight, and preferably washable material that enwraps the patient's torso, and also has at least seven non-adjustable hand-grip lift components with sturdy and durable construction and attachment. In some preferred embodiments, nine hand-grip lift components are used, with six hand-grip lift components preferably situated bilaterally on the vest front, and three hand-grip lift components situated on the vest back. For vest durability during repeated patient lifting, reinforcement lining stitching is secured adjacent to or near at least one end of all hand-grips lift components. Interior adjustment ties, padded neck and armhole openings, mesh fabric, and a collar may also contribute to patient comfort. Overall, the manual transfer vest promotes safety in preventing injuries, thereby reducing medical costs. | 0 |
BACKGROUND
This invention relates to devices for applying heat to the hair to activate permanent wave solutions, hair reconditioners, hair bleachers, or other heat-activated or heat-accelerated solutions used on the hair.
In a process currently used by beauty shops to form permanent waves, a liqiud permanent wave solution is applied to the hair, and the hair is then coiled around a number of rollers placed about the patron's head. Commonly used low-pH permanent wave solutions contain thio-sulphur compounds, or the like, which require heat to activate the permanent wave process. In the most frequently used method of applying heat to the hair, a shower cap is placed over the head, and the patron then sits under a hot air blower which heats the permanent wave solution. During this process of applying heat to the permanent wave, the beautician must frequently remove the shower cap to check the rollers to determine whether processing is complete for each roller. Although this checking is an essential activity, it can be a tedious and time-consuming job because of the failure of the heat source to provide a uniform rate of heat processing over the entire hair structure. The inability to produce a uniform rate of heat processing also requires substantially more processing time.
To reduce the amount of time required to process permanent wave solutions, several alternatives to hot air blowers have been proposed. In one instance, it has been proposed to place an array of infra-red heat lamps around the patron's head. It has also been proposed to use an electrically heated cap which is draped over the patron's head and fits rather loosely around the head. One such heat cap includes a drawstring which ties under the patron's chin. The infra-red lamps and heat caps proposed thus far have not significantly reduced processing time. They also have other disadvantages which make them even less attractive than hot air blowers. For example, a heat lamp array can be very cumbersome to use, and known heat caps have not been developed so they can be easily removed without disturbing the permanent wave when the beautician checks the rollers in the patron's hair.
SUMMARY OF THE INVENTION
The present invention provides a heat cap which overcomes the disadvantages of the processing techniques discussed above and, in turn, produces an essentially uniform rate of heat processing for the hair.
Briefly, the heat cap of this invention, according to a presently preferred embodiment, includes a heat-resistant flexible cap structure having a hollow interior containing a flexible, sheet-like heating element for directing heat outwardly from the cap in an essentially uniform heat pattern. The cap and heating element closely conform to the three-dimensional size and shape of the permanent wave structure to effectively transfer the heat from the cap to the hair.
In a preferred form of the invention, the heating element includes an electrical resistance heating film disposed within a selected pattern throughout the interior of the cap. The heating film preferably is supported within the cap by a dielectric sheet comprising an electrically insulative material having sufficient flexibility to closely conform to the three-dimensional contour of the patron's head. The dielectric sheet is resistant to prolonged heat in the range of temperatures used with thermally-activated processing solutions for the hair.
In a preferred form of the invention, the cap opens and closes along a pair of splits extending inwardly from a lower peripheral edge of the cap. The splits provide a pair of flexible and independently movable flaps on opposite sides of the cap. Cooperating fastening means are disposed along each split for releasably attaching selected portions of the flaps to the cap in the vicinity of each split. In this way, the cap is pliable and can be quickly and easily form-fitted to the head so that the heat generated within the cap can be applied directly to all rollers used in the permanent wave with minimum heat transfer losses. This results in reduced processing time and produces a uniform rate of processing, independently of the character of the permanent wave, or the size of the rollers, for example.
Preferably, the heat element is arranged in a pattern throughout the cap which produces a selected heat distribution pattern over the area of the cap. By conforming the cap closely to the shape of the head, the selected heat distribution pattern can produce an essentially uniform rate of processing for the entire permanent wave.
These and other aspects of the invention will be more fully understood by referring to the following detailed description and the accompanying drawings.
DRAWINGS
FIG. 1 is a fragmentary perspective view showing a heat cap according to this invention;
FIG. 2 is a plan view showing an electrical resistance heating element used inside the heat cap shown in FIG. 1;
FIG. 3 is a partly schematic elevation view, partly broken away, taken on line 3--3 of FIG. 1;
FIG. 4 is a schematic cross-sectional view, highly exaggerated in relative size, taken on line 4--4 of FIG. 3; and
FIG. 5 is an electrical schematic diagram illustrating an electrical circuit used in conjunction with the heating element shown in FIG. 2.
DETAILED DESCRIPTION
Referring to the drawings, an electrically operated hair processing heat cap 10 includes a flexible cap structure 12 for fitting over the head of a human being. The cap structure is shaped so that, in its closed position it will be generally spherically shaped to cover at least the area of the head within the hairline and to conform closely to the three-dimensional contour of the permanent wave structure for the hair.
Preferably, the cap structure 12 includes an imperforate outer cover 14 made from a heat-resistant flexible sheet-like material having good thermal insulation properties. A presently preferred material is a vinyl-coated fabric, although vinyl plastic sheeting, such as flexible polyvinyl chloride sheeting resembling leather or the like, also can be used.
The underside of the cap structure 12 includes an imperforate inner liner 16 made from a heat-resistant, moisture impermeable flexible sheet-like material. The inner liner 16 also is chemically resistant to permanent wave solutions, neutralizers, and the like which are typically used on the hair. For example, the material is resistant to chemical reducing compounds containing the mercaptan group (i.e., ammonium thioglycollate, thioglycerol, thiolatic acid, glycerol ester of thioglycolic acid, etc.). The preferred liner is made of the same material as the outer cover 14, namely a vinyl-coated fabric. Preferably, the vinyl-coated surfaces of the outer cover 14 and the inner liner 16 face the exterior of the heat cap.
The outer cover 14 and inner liner 16 each are constructed from separate sections of material initially cut into desired shapes in flat form and then stitched together to form a three-dimensional cap structure. The outer cover preferably comprises a continuous piece of material gathered together by darted stitching 18, 20 and 22 at the front of the cap and by a pair of darted stitching seams (not shown) at the rear of the cap. Similarly, the inner liner 16 is gathered by substantially indentical front and rear darted stitching. A rear darted stitching seam 24 is shown in FIG. 1. The top cover 14 and inner liner 16 are stitched together by a peripheral bias seam 26 extending around the perimeter of the cap. The perimeter bias seam improves the peripheral fit of the heat cap when the cap is conformed to the shape of the permanent wave structure.
The heat cap opens and closes along an elongated first split 28 extending inwardly from the perimeter seam 24 in the vicinity of the temple on one side of the head, and a separate elongated second split 30 extending inwardly from the perimeter seam 24 in the temple region on the opposite side of the head. Preferably each split extends inwardly from the peripheral seam by a distance less than about one-half the vertical height of the cap in its closed position. When the cap is in its closed position its vertical height is between about 7 to 8 inches, and each split extends inwardly at the temple area by a distance of about 3 inches. The first split 28 forms an independently movable flexible flap 32 in one temple region of the cap, and the split 30 forms a separate independently movable flexible flap 34 in the other temple region of the cap.
The first and second splits are arranged so that the flaps 32 and 34 will project toward the front of the head when the cap is worn on the head. FIG. 1 illustrates both flaps extending toward the frontal region of the cap. The flaps can be manipulated by the beautician to overlap adjacent temple regions of the cap. In this way, the flaps can be used to adjust the closeness of the cap to the permanent wave by pulling the flaps forward to increase their overlap with respect to the adjacent temple regions of the cap outer surface. It is preferred to use the cap by having the flaps overlap the outer surface of the cap, rather than the flaps being on the inside of the cap.
Releasable fastening means are secured to the inside surface of each flap and to the adjacent temple regions of the cap outer surface overlapped by the flaps. Although various types of fastening devices may be used, the preferred fastening means comprise cooperating types of thistle-cloth material, commonly sold under the trademark Velcro. The Velcro material is preferably spread over a substantial area of each flap and the corresponding nearby temple region of the cap. This provides means for releasably attaching the flaps to the cap in a variety of selected overlapping orientations so that the cap can be adjusted to easily conform to a wide variety of shapes and sizes of permanent wave structures. As to the heat cap shown in the drawings, the fastening means comprise a first strip 36 of hook-type Velcro material secured to the inside surface of the flap 32, a cooperating strip 38 of a pile-type of Velcro material secured to the outer surface of the cap adjacent the flap 32, a strip 40 of hook-type Velcro material secured to the inside surface of the second flap 34, and a strip 42 of pile-type Velcro material secured to the cap outer surface adjacent the flap 34. Preferably, the Velcro material covers a substantial area, each strip being between about 3 to 4 inches long and about 11/2 to 21/2 inches in height.
An electrical heating element 43 and controls for the heating element 43 are contained in the hollow interior area of the cap between the outer cover 14 and the inner liner 16. The electrical heating element 43 directs heat automatically from the underside of the cap to heat thermally-activated permanent wave solutions or the like used on the hair. The heating element 43 preferably comprises an electrical resistance heating film 44 of electrically conductive metal applied in a relatively thin layer to a flexible carrier sheet 46 of electrically insulative material which is sufficiently flexible to conform to the shape of the head. The electrically insulative sheet 46 (hereafter referred to as a dielectric sheet 46), also is sufficiently heat-resistant to withstand prolonged use in contact with the electrically heated film 44 at temperatures normally used in hair processing, say between about 130° to about 195° F. By way of example, certain highly flexible films made from certain synthetic resinous materials are unsuitable as a dielectric sheet for the purposes of this invention if prolonged use of the film at the high temperatures contemplated herein results in a loss of the flexible properties of the film. It has been discovered that a dielectric sheet of aramid paper provides the desired properties of long term flexibility and heat resistance. The preferred aramid paper is Nomex (trademark of DuPont) Type 410 paper which is produced from short fibers (floc) and smaller binder particles (fibrids) of a high-temperature-resistant polyamide polymer formed into a sheet product without additional binders or fillers.
Preferably, the electrical resistance heating film 44 is sandwiched between a pair of dielectric sheets 46. In the preferred form of the invention, the dielectric sheet 46 of aramid paper nearest the outside of the heat cap is 2 mil. thick and the dielectric sheet 46 of aramid paper nearest the underside of the heat cap is 3 mil. thick.
The electrical resistance heating film 44 preferably is a thin layer of chemically milled metal foil laminated between the two dielectric sheets 46. The dielectric sheets are cut into the configuration illustrated in FIG. 2 and the conductive foil is laminated between the sheets. Preferably, the foil is in the pattern illustrated in FIG. 2. The preferred configuration of the dielectric sheets enables them to cover substantially the entire surface area of the interior of the heat cap when the heat cap is in its closed position worn on the head; and the conductive foil is applied to the dielectric sheet in a pattern which covers a major area of the sheet. In this way, the heat generated, when the conductive foil 44 is energized, is spread in a substantially uniform heat pattern over the entire three-dimensional surface area heat cap. The conductive metal foil preferably is in a conductive meander pattern having substantially parallel conductive arms with narrow elongated insulating spaces between the arms and conductive bridges joining the ends of the arms. The metal foil is so thin that its thickness is minute compared with the surface dimensions of the foil, while the pattern is distributed over and occupies the greater part of the area within the boundaries of the pattern. The film is thin and flexible and provides a substantially instantaneous and relatively uniform source of heat. The heat pattern generated by the foil is uniform in the sense that heat produced in an area defined by certain dimensions of the pattern is essentially homogeneous and not subject to wide variations within the area, although the foil can be arranged to produce a heat gradient from region to region of the cap, as described below.
FIG. 2 illustrates the preferred configuration of the heating element in which the dielectric sheets 46 are cut into a pattern which provides a central region 48 for covering the top crown area of the head, regions 50 and 52 for covering left and right portions, respectively, of the front crown area of the head, a region 54 for covering the nape, regions 56 and 58 for covering left and right front portions of the crown and temple, respectively, and regions 60 and 62 for covering left and right rear portions of the crown and temple, respectively. The conductive foil 44 is preferably arranged in a pattern which will maintain the same temperature level in different areas of the head, although the heat density transferred to different regions of the head varies. To accomplish this, the foil conductor is arranged in a selected pattern to provide power densities which vary with respect to their location in the heat cap. In a preferred form of the invention, the pattern of the foil conductor 44 provides a watt density of 0.578 watts/sq.in. for the front crown, 0.525 watts/sq.in. for the top crown, 0.566 watts/sq.in. for the nape, and 0.392 watts/sq.in. for the left and right temple regions of the head. The total maximum power of the heat cap is 100 watts at 120 volts. This gradient in watt densities provides a substantially uniform rate of processing for the hair, since different areas of the hair require different amounts of heat for processing purposes. That is, the hair in the temple area of the head requires less heat density than the hair at the top of the head, and therefore the heat cap will produce a substantially uniform rate of processing.
FIG. 4 cross-sectionally illustrates the preferred laminated structure of the heating cap 43. The conductive foil 44 is bonded between the dielectric sheets 46 by corresponding layers 64 of adhesive, preferably an adhesive designated EC 2290 and sold by 3M Co. The conductive foil 44 is a one mil. thick foil comprising an alloy of nickel and chromium and sold under the trademark Inconel by Huntington Alloy Products, Division of International Nickel Co., Inc. Preferably, the heating element also includes a layer 66 of heat-insulative material for reducing thermal losses. The preferred insulative layer 66 is a 1/4 inch thick flexible polyurethane foam having a density of 2 lbs.cu.ft. The insulating layer is bonded to the side of the heating element adjacent the outer cover 14. Preferably, the foam insulating layer 66 is bonded by a layer 68 of adhesive designated Scotch Grip 4475 sold by 3M Co.
The electrical heating system provides controls for adjusting the heat generated by the heat cap. Preferably, the electrical system includes a two-conductor electrical cord 70 having a two-prong plug 72 at one end for connection to a conventional 120 volt a.c. power source. The conductor wires of the cord 70 are connected to the primary terminals 74 of an electrical switch 76 which can be set at a low, high, or off position. The heating film 44 includes terminals 80 and 84. The secondary terminals 78 of the switch 76 are connected to the terminals 80, 82, 83 of the heating element by a three-conductor electrical cord having conductors 86, 88 and 90. The secondary side of the switch is connected to the heating element through three thermostats. A low temperature thermostat 92 has a low temperature setting, preferably 140° F. Two other thermostats 94 and 96 are connected in series and have a high temperature setting, preferably 185° F. The switch 76 applies the primary voltage between the terminals 80 and 83 in the low setting of the switch. In this setting all three thermostats are connected in series with the heating element so that the low temperature thermostat 92 controls the temperature output of the heating element. In this position the two high temperature thermostats 94 and 96 act as safety thermostats. In the high temperature setting of the switch 76, the primary voltage is applied between the terminals 80 and 82 so that only the two high temperature thermostats are connected in series with the heating element. Preferably, the thermostats are placed in a location within the interior of the heat cap overlying the portion of the heating element in the nap area of the cap. The thermostats sense the temperature at the surface of the heating element and operate so as to maintain the heating element at the temperature selected by the setting of the switch.
The present invention provides a heat cap which produces the uniform rate of heat processing especially desirable for acid-balanced, heat-activated permanent waving solutions. The heat cap also is easy to use and safe in operation. The structure of the cap makes it possible to easily adjust to various head sizes, the cap being fitted so close to the rollers that heat retention is high and processing time is substantially reduced. The cap also can be quickly and easily opened for frequent inspection of the rollers without disrupting the permanent wave structure. The use of the flexible dielectric sheet and resistive metal foil heating element provides significant advantages over a heat cap which would use electrically insulated conductor wires spaced part throughout the cap. For example, if such conductor wires were spaced apart by a distance of 1/2 to 3/4 inch intervals, the heat differential between wires is about 40° F. Moreover, the insulation material acts as a heat sink which requires warm up time (as opposed to the present invention which does not require a warm up time) and also requires a higher operating temperature then the metal foil conductor of the present invention. In contrast, the heat cap of this invention can apply a generally uniform heat pattern to the hair, and the temperature gradient of the uniform heat pattern can vary with respect to different regions of the hair to produce a uniform rate of processing. This greatly reduces the effort required in checking the rollers and results in shorter processing time. | A heat cap for reducing processing time of permanent waves for the hair includes a cap which fits over the head, and a thermostatically controlled electrical heating element inside the cap for applying a selected heat distribution pattern to thermally-activated permanent wave solutions applied to the hair. The heating element comprises an electrical resistance heating film, preferably a meander pattern of conductive metal foil supported by a flexible, high temperature-resistant, fibrous dielectric sheet, such as aramid paper. The conductor develops a selected heat distribution pattern to be developed within the cap which, in turn, produces a generally uniform rate of heat processing for the permanent wave. The cap opens and closes along a pair of splits in the temple regions of the cap. Fasteners, preferably cooperating sections of Velcro material, are located along opposite sides of each split and are used to releasably close selected overlapping portions of the cap adjacent each split so the cap will closely conform to the size and shape of the head and the permanent wave structure to apply heat uniformly to all rollers in the permanent wave. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional application of U.S. Ser. No. 11/341,535 filed Jan. 30, 2006 now abandoned, the disclosure of which is incorporated herein by reference in its entirety.
This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2005-296535, filed on Oct. 11, 2005, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an optical receiver that regenerates data from an optical signal based on an optimal decision threshold that is set dynamically according to the receiving power of the optical signal.
2. Description of the Related Art
With the popularization of the Internet in recent years, data traffic in communication networks has been significantly increasing. To cope with the increase of data traffic, an ultra-broadband photonic network employing a dense wavelength division multiplexing (DWDM) technology has been developed. An ultra-long-haul data communication can be performed with DWDM transmission, which uses an optical fiber including several tens of wavelength channels and a plurality of optical amplifiers connected in cascade on the optical fiber. In such ultra-long-haul data communication, however, the interference between wavelength channels significantly increases and the optical signal to noise ratio (OSNR) is seriously deteriorated due to optical noise from the optical amplifiers. Especially, data error due to the optical noise has become a bottleneck for DWDM transmission because it cannot be prevented by improving the sensitivity of an optical receiver. Therefore, to overcome this optical noise bottleneck an improvement of the error correction technology performed in the optical receiver is strongly needed.
If the optical receiver corrects the data error using forward error correction (FEC), a bit error rate (BER) of the optical receiver can be obtained from a result of the error correction. On the other hand, the receiving characteristics of the optical receiver can be improved by optimizing its decision threshold that varies depending on the OSNR or a state of chromatic dispersion due to long-haul transmission. Therefore, the performance of the optical receiver can be improved by performing a feedback control based on the BER and by adjusting the decision threshold to the optimal level.
FIG. 17 is a block diagram of a conventional optical receiver for DWDM transmission. As shown in FIG. 17 , an optical receiver 1 includes a photodiode (PD) 2 , a trans-impedance amplifier (TIA) functioning as a preamplifier 3 , a variable-gain amplifier 4 , a gain-control amplifier 5 , a clock/data recovery (CDR) 6 , a forward error correction (FEC) unit 7 , a controller 8 , and a digital-to-analog converter (DAC) 9 .
The PD 2 converts an optical input signal into an electrical signal. The preamplifier 3 , the variable-gain amplifier 4 , and the gain-control amplifier 5 perform reshaping of the electrical signal. The CDR 6 performs regeneration and retiming of the reshaped electrical signal. The FEC 7 , the controller 8 , and the DAC 9 are provided to adjust the decision threshold according to the amplitude of the reshaped electrical signal as shown in FIG. 18 (see, for example, Japanese Patent Application Laid-Open No. H2-288640).
However, the optical receiver 1 needs large circuit size and its control becomes complicated because it has to perform variable-gain control to keep constant reshaped electrical signal. Furthermore, the gain of the preamplifier 3 needs to be small to prevent saturation of amplitude when the input power of optical signal increases, thereby making it difficult to improve the sensitivity of the optical receiver 1 .
On the other hand, another optical receiver achieving high sensitivity with a simple configuration has also been suggested. The optical receiver includes a high-gain limiting amplifier, and a direct current (DC) feedback circuit for controlling the DC level of the positive signal and the negative signal output from the limiting amplifier. The sensitivity of the optical receiver can be improved by increasing the gain of the preamplifier, while reducing the circuit size of the optical receiver.
In such an optical receiver, however, the relation between the decision threshold of optical receiver and a feed-backed threshold control signal from an forward error correction (FEC) unit is not unique, because the condition of signal in the optical receiver greatly differs depending on, for example, the receiving power of the signal. The limiting amplifier performs a complex operation in the DC feedback control. Specifically, as long as the amplitude of an input signal is less than predetermined limiting amplitude, the limiting amplifier performs a linear operation and linearly amplifies the input signal. On the other hand, when the amplitude of the input signal reaches the limiting amplitude, the limiting amplifier performs a limiting operation and extracts a part of the input signal near cross points. The wide dynamic range of the receiving power makes it difficult to set an appropriate decision threshold, using the threshold control signal, for respective input power. As a result, a sufficient error correction cannot be achieved.
SUMMARY OF THE INVENTION
It is an object of the present invention to at least solve the above problems in the conventional technology.
An optical receiver according to an aspect of the present invention includes: a converting unit that converts an optical signal into an electrical signal; an amplifying unit that amplifies the electrical signal; a regenerating unit that regenerates the electrical signal amplified by the amplifying unit; a correcting unit that performs correction of an error included in the electrical signal regenerated by the regenerating unit; a monitoring unit that performs monitoring of an photo current flowing through the converting unit; and a control unit that calculates a decision threshold based on a result of the correction and a result of the monitoring.
The other objects, features, and advantages of the present invention are specifically set forth in or will become apparent from the following detailed description of the invention when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an optical receiver according to a first embodiment of the present invention;
FIG. 2 is a schematic illustrating an operation of the optical receiver shown in FIG. 1 ;
FIGS. 3 to 6 are waveform diagrams illustrating the output amplitude of a limiting amplifier shown in FIG. 1 ;
FIG. 7 is a flowchart of a decision threshold setting process according to the first embodiment;
FIG. 8 is a block diagram of an optical receiver according to a second embodiment of the present invention;
FIG. 9 is a block diagram of an optical receiver according to a third embodiment of the present invention;
FIG. 10 is a block diagram of an optical receiver according to a fourth embodiment of the present invention;
FIG. 11 is a block diagram of an optical receiver according to a fifth embodiment of the present invention;
FIG. 12 is a block diagram of an optical receiver according to a sixth embodiment of the present invention;
FIG. 13 is a block diagram of an optical receiver according to a seventh embodiment of the present invention;
FIG. 14 is a block diagram of an optical receiver according to an eighth embodiment of the present invention;
FIG. 15 is a block diagram of an optical receiver according to a ninth embodiment of the present invention;
FIG. 16 is a flowchart of a decision threshold setting process according to the ninth embodiment;
FIG. 17 is a block diagram of a conventional optical receiver; and
FIG. 18 is a waveform diagram illustrating the output amplitude of the conventional optical receiver.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Exemplary embodiments of the present invention will be explained in detail with reference to the accompanying drawings.
FIG. 1 is a block diagram of an optical receiver according to a first embodiment of the present invention. An optical receiver 10 includes a power monitor 11 , a photodiode (PD) 12 , a preamplifier 13 , a limiting amplifier 14 , a direct current (DC) feedback amplifier 15 , a clock/data recovery (CDR) 16 , a forward error correction (FEC) unit 17 , and a controller 18 .
The PD 12 converts an optical input signal into an electrical signal. The preamplifier 13 and the limiting amplifier 14 amplify the electrical signal. An output signal from the preamplifier 13 is input to one of the input terminals of the limiting amplifier 14 . The DC feedback amplifier 15 feedbacks an output signal from the limiting amplifier 14 back to the other input terminal of the limiting amplifier 14 . Thus, the DC feedback amplifier 15 controls the DC level of the positive signal and the negative signal output from the limiting amplifier 14 . The CDR 16 regenerates and retimes the output signal from the limiting amplifier 14 .
The FEC 17 corrects data error included in the regenerated signal. The power monitor 11 monitors a photo current flowing through the PD 12 . The controller 18 calculates an optimal decision threshold according to the receiving power and the bit error rate. Specifically, the controller 18 calculates the optimal decision threshold based on a monitor signal from the power monitor 11 , which corresponding to the monitored reception power, and a threshold control signal from the FEC 17 , which corresponding to the bit error rate. The calculated decision threshold is converted into an analog signal in the controller 18 , and is set to the DC feedback amplifier 15 .
FIG. 2 is a schematic illustrating an operation of the optical receiver 10 . FIGS. 3 and 4 are waveform diagrams illustrating the output amplitude of the limiting amplifier 14 performing the linear operation with the decision threshold being set at 50% and 30%, respectively. FIGS. 5 and 6 are waveform diagrams illustrating the output amplitude of the limiting amplifier 14 performing the limiting operation with the decision threshold being set at 50% and 30%, respectively. The above decision thresholds (%) are normalized with respect to the signal amplitude.
As shown in FIGS. 3 to 6 , the limiting amplifier 14 performs the linear operation and the limiting operation. In the linear operation, the decision threshold is changed in proportion to the reception power as shown in FIG. 2 because the signal level of the positive signal and the negative signal changes due to the DC feedback control. On the other hand, in the limiting operation, the signal level does not change but the pulse width of the signal changes according to the rising edge timing and the falling edge timing of the signal. Therefore, as long as the rising and falling timings are stable in the signal, the decision threshold is kept substantially constant in the limiting operation as shown in FIG. 2 .
The controller 18 calculates an optimal decision threshold based on the above operations of the limiting amplifier 14 . The DC feedback amplifier 15 controls the DC level of the feedback signal to the limiting amplifier 14 based on the decision threshold set by the controller 18 , to control the DC level of the positive signal and the negative signal output from the limiting amplifier 14 .
FIG. 7 is a flowchart of a decision threshold setting process performed by the controller 18 . The controller 18 receives the monitor signal indicating the receiving power of an optical signal from the power monitor 11 , and sets an initial value of the decision threshold (step S 1 ). Then, the controller 18 calculates an initial value of the error rate based on the initial value of the decision threshold and the threshold control signal from the FEC 17 (step S 2 ). The controller 18 determines whether the error rate satisfies a predetermined condition (step S 3 ). When the error rate satisfies the condition (“YES” at step S 3 ), the process is completed.
On the other hand, when the error rate does not satisfy the condition (“NO” at step S 3 ), the controller 18 receives updated monitor signal from the power monitor 11 , and changes the decision threshold (step S 4 ). Then, the controller 18 calculates the error rate (step S 5 ), and determines whether the error rate satisfies the condition (step S 6 ). When the error rate does not satisfy the condition (“NO” at step S 6 ), the process returns to step S 4 . The process from step S 4 to step S 6 is repeated until an error rate that satisfies the condition is obtained. When the error rate satisfies the condition (“YES” at step S 6 ), the process is completed.
FIG. 8 is a block diagram of an optical receiver according to a second embodiment of the present invention. An optical receiver 20 shown in FIG. 8 performs a DC feedback control different from the DC feedback control explained in the first embodiment. Specifically, the optical receiver 20 includes a DC feedback amplifier 25 instead of the DC feedback amplifier 15 shown in FIG. 1 . The output signals from the limiting amplifier 14 are input to the DC feedback amplifier 25 . The output signal from the DC feedback amplifier 25 controls a current source 22 connected to the PD 12 and the preamplifier 13 .
In a similar manner as in the first embodiment, the decision threshold calculated by the controller 18 is set in the DC feedback amplifier 25 . The output signal from the preamplifier 13 is input to one of the input terminals of the limiting amplifier 14 as it is, and also input to the other input terminal through a low pass filter (LPF) 21 that extracts the DC level of the output signal of preamplifier.
The DC feedback amplifier 25 performs a DC feedback control based on the decision threshold set by the controller 18 , to control the DC level of the positive signal and the negative signal that are output from the preamplifier 13 and input to the limiting amplifier 14 .
FIG. 9 is a block diagram of an optical receiver according to a third embodiment of the present invention. An optical receiver 30 shown in FIG. 9 performs a DC feedback control different from the DC feedback control explained in the second embodiment. Specifically, the optical receiver 30 includes a DC feedback amplifier 35 instead of the DC feedback amplifier 25 shown in FIG. 8 . The output signal from the preamplifier 13 is input to the DC feedback amplifier 35 . The output signal from the DC feedback amplifier 35 controls the current source 22 .
In a similar manner as in the second embodiment, the decision threshold calculated by the controller 18 is set in the DC feedback amplifier 35 . However, in the third embodiment, the output signal from the preamplifier 13 is subjected to a feedback control performed by the DC feedback amplifier 35 , to control the DC level of the positive signal and the negative signal to be input to the limiting amplifier 14 .
FIG. 10 is a block diagram of an optical receiver according to a fourth embodiment of the present invention. An optical receiver 40 shown in FIG. 10 controls, instead of performing the DC feedback control, a DC level of the output signal from the limiting amplifier 14 directly based on the decision threshold calculated by the controller 18 . The limiting amplifier 14 and the CDR 16 are AC-coupled via capacitors 41 and 42 , and the decision threshold calculated by the controller 18 is input to one of the input terminals of the CDR 16 by an adder 43 .
FIG. 11 is a block diagram of an optical receiver according to a fifth embodiment of the present invention. The configuration of an optical receiver 50 shown in FIG. 11 is similar to that of the optical receiver 40 according to the fourth embodiment (see FIG. 10 ). However, unlike the optical receiver 40 , the optical receiver 50 performs the same DC feedback control as that of the first embodiment (see FIG. 1 ). Specifically, the DC feedback amplifier 15 of the optical receiver 50 feeds back the output signal from the limiting amplifier 14 to one of the input terminals of the limiting amplifier 14 . However, the decision threshold calculated by the controller 18 is not input to the DC feedback amplifier 15 .
FIG. 12 is a block diagram of an optical receiver according to a sixth embodiment of the present invention. The configuration of an optical receiver 60 shown in FIG. 12 is similar to that of the optical receiver 40 according to the fourth embodiment (see FIG. 10 ). However, unlike the optical receiver 40 , the optical receiver 60 performs the same DC feedback control as that of the third embodiment (see FIG. 9 ). Specifically, the DC feedback amplifier 35 of the optical receiver 60 controls the current source 22 connected to the PD 12 and the preamplifier 13 by inputting the output signal from the preamplifier 13 to the current source 22 . However, the decision threshold calculated by the controller 18 is not input to the DC feedback amplifier 35 .
FIG. 13 is a block diagram of an optical receiver according to a seventh embodiment of the present invention. The configuration of an optical receiver 70 shown in FIG. 13 is same as that of the optical receiver 50 according to the fifth embodiment (see FIG. 11 ). However, in the optical receiver 70 , the decision threshold calculated by the controller 18 is input to the DC feedback amplifier 15 as in the optical receiver 10 according to the first embodiment (see FIG. 1 ). In other words, in the optical receiver 70 , the DC level of the positive signal and the negative signal output from the limiting amplifier 14 is controlled at both sides of the limiting amplifier 14 (that is, the input side and the output side). According to the seventh embodiment, the decision threshold can be adjusted appropriately even when the relation between the reception power and the decision threshold is more complicated.
FIG. 14 is a block diagram of an optical receiver according to an eighth embodiment of the present invention. The configuration of an optical receiver 80 shown in FIG. 14 is similar to that of the optical receiver 10 according to the first embodiment (see FIG. 1 ), except for including an analog operating unit 88 , such as an operational amplifier, instead of the controller 18 . The analog operating unit 88 performs an analog processing to set the decision threshold based on the monitor signal and the threshold control signal. With the above configuration, the decision threshold is output as an analog signal from the analog operating unit 88 .
FIG. 15 is a block diagram of an optical receiver according to a ninth embodiment of the present invention. The configuration of an optical receiver 90 shown in FIG. 15 is similar to that of the optical receiver 10 according to the first embodiment (see FIG. 1 ), except for including a controller 91 , a calculator 92 , and a DAC 93 instead of the controller 18 . The controller 91 generates a normalized threshold control signal based on the threshold control signal input from the FEC 17 . The calculator 92 calculates an optimal decision threshold according to the reception power and the error rate. Specifically, the calculator 92 calculates the optimal decision threshold based on the normalized threshold control signal input from the controller 91 and the monitor signal input from the power monitor 11 . The DAC 93 converts the optimal decision threshold output from the calculator 92 from digital to analog, and set the decision threshold to the DC feedback amplifier 15 .
FIG. 16 is a flowchart of a decision threshold setting process performed by the controller 91 and the calculator 92 . The controller 91 sets an initial value of the normalized threshold (step S 11 ). Then, the calculator 92 receives the monitor signal from the power monitor 11 , and sets an initial value of the decision threshold (step S 12 ). The calculator 92 calculates an initial value of the error rate based on the initial values of the normalized threshold and the decision threshold (step S 13 ), and determines whether the error rate satisfies a predetermined condition (step S 14 ). When the error rate satisfies the condition (“YES” at step S 14 ), the process is completed.
On the other hand, when the error rate does not satisfy the condition (“NO” at step S 14 ), the controller 91 changes the normalized threshold (step S 15 ). The calculator 92 receives updated monitor signal from the power monitor 11 , and changes the decision threshold (step S 16 ). The calculator 92 recalculates the error rate based on the normalized threshold and the decision threshold (step S 17 ), and determines whether the error rate satisfies the condition (step S 18 ).
When the error rate does not satisfy the condition (“NO” at step S 18 ), the process returns back to step S 15 , and the process from step S 15 to step S 18 is repeated until an error rate that satisfies the condition is obtained. When the error rate satisfies the condition (“YES” at step S 18 ), the process is completed.
The configuration according to the ninth embodiment is suitable for a case in which the controller 91 and the calculator 92 are separately provided. For example, a module formed by the calculator 92 , the DAC 93 , and the PD can be mounted on a substrate provided with the controller 91 . The controller 18 or the analog calculator according to the first to the eighth embodiments may also be provided as two independent components of the controller and the calculator.
According to the embodiments described above, an optimal decision threshold is set according to the receiving power varying in a wide range, thereby improving the performance of the error correction performed by an optical receiver. Moreover, a high-quality and error-free optical transmission can be achieved by applying a high-gain error correction technology to the highly-sensitive optical receiver with a limiting amplifier.
Although the invention has been described with respect to a specific embodiment for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art which fairly fall within the basic teaching herein set forth. | An optical receiver includes: a converting unit that converts an optical signal into an electrical signal; an amplifying unit that amplifies the electrical signal; a regenerating unit that regenerates the amplified electrical signal; a correcting unit that performs correction of an error included in the regenerated electrical signal; a monitoring unit that performs monitoring of an optical current flowing through the converting unit; and a control unit that calculates a decision threshold based on a result of the correction and a result of the monitoring. | 7 |
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates to an improved weaving machine to produce figured fabrics, that is fabrics having different colors and patterns and particularly to a knitting machine of the kind in which a "crochet-machine" and a "jacquard device" are associated on the same bearing frame.
It is known that there have been on the market for a long time knitting machines known as crochet-machines. These machines have a rather simple structure and are suitable to produce simple knitted figured fabrics. These machines have become particularly versatile and sophisticated when the so-called "jacquard device" has been applied thereto. Owing to the presence of this device which is disposed above the crochet-machine, it is possible to achieve very elaborate fabrics.
It was found, however that the combination of a crochet-machine with a jacquard device is not sufficient to allow the achievement of very figured fabrics having a great variety of colors and patterns. Furthermore, it was found that known machines can give good results only if they are suitably arranged in order to obtain a determined fabric. In other words, many problems arise with these machines when it is necessary to change the type of fabric to be produced.
This is a rather unfavorable situation when these machines have to be used to produce fabrics that are particularly subjected to the fashion and to the changing of the same. In this case the presence of a knitting machine suitable to change its production without giving rise to particular problems is required. This kind of universal machine giving products of high quality is particularly required by the middle-sized factories in order to obtain all types of fabrics by means of a sole machine of a general kind.
In this context it is also necessary that a knitting machine having reduced overall dimensions and suitable to be located in places that are not especially arranged for the purpose should be available. In fact, it should be understood that the crochet-machines of the known art, provided with a jacquard device, have very big vertical dimensions as said jacquard device is disposed above the crochet-machine. This arrangement is necessary as it is required that the yarns unwound from the jacquard device and directed towards the crochet-machine should not get entangled.
Furthermore, it is not possible to reduce the height dimensions of the jacquard device without considerably altering the device itself.
OBJECTS
In this situation the technical task on which the present invention is based is to conceive a knitting machine having the above features as to its versatility, high quality level and possibility to be readily fitted for the production of different kinds of fabrics.
Within the scope of this technical task it is an important object of the present invention to conceive a knitting machine suitable to obtain the most varied kinds of fabrics by simply changing the program controlling the machine.
A further important object of the present invention is to conceive a substantially new knitting machine particularly efficient in all its technical devices, although the basic structure of the same is the result of the combination of a crochet-machine and a jacquard device.
A still further object of the present invention is to conceive a knitting machine having reduced overall dimensions, particularly reduced height dimensions, in order to allow the positioning of the machine in any room having a suitable area.
SUMMARY OF THE INVENTION
These and still further objects that will become more apparent in the following are attained by an improved knitting machine according to the invention for the production of figured fabrics, that is having different colors and patterns, of the kind associating a crochet-machine and a jacquard device on a sole bearing frame and comprising active members such as a needle-bar movable in an axial direction to the needles, a warp yarn guide bar disposed adjacent the needles and suitable to oscillate in a direction parallel to the lying plane of the needles and to rotate perpendicularly to the same plane, an under-yarn guide bar suitable to oscillate in a direction parallel to the needle plane and perpendicularly to the same, a projection carrier bar movable at right angles to the needle plane, rods suitable to support tubular weft yarn guides disposed side by side on plates parallel to said needle bar and transversely to the needle plane, said plates being movable along their own plane and parallelly to said needle bar in order to define the working oscillations of said rods; and further comprising selection and control members for said active members designed to cause the same active members to intervene according to a predetermined program, as well as feeding devices for the yarns forming the fabric and conveying means for the produced fabric; said knitting machine being characterized in that said rods are rotatably supported by pivot pins that develop at right angles to said plates, in that is provided with stop members for said rods designed to allow the same to oscillate symmetrically with respect to vertical planes and to cause the maximal linear amplitudes of said tubular weft yarn guides which correspond to the double distance of two needles in succession, and in that said selection and control members include a plurality of kinematic chains suitable to position each of said rods angularly and independently of the adjacent rods.
Advantageously, said selection and control members comprise hooked needles, a trailing device for said hooked needles, control needles for said hooked needles and a selection drum for said hooked needle control needles, and they are characterized in that they are disposed at the side of said active members, tie rods being provided for connecting said hooked needles to said rods having a prevalently horizontal development, at the inside of metal sheaths supported by a frame mounted above said rods.
Further features and advantages will become more evident from the description of a preferred but not exclusive embodiment of the invention, given hereinafter by way of example only, with reference to the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic front view of the machine as a whole, according to the invention;
FIG. 2 is a side sectional view of the machine as a whole;
FIG. 3 shows a detail of FIG. 1 to an enlarged scale;
FIG. 4, in turn, shows a detail of FIG. 3 to a further enlarged scale;
FIG. 5 shows a detail of FIG. 3 according to an angle rotaed through 90°;
FIG. 6 shows some elements seen in FIG. 5 to the same scale and during different operating steps;
FIG. 7 is a front detailed view of a portion of the machine according to the invention, that portion being diagrammatically shown on the right-hand side of FIG. 1;
FIG. 8 is a part side view of FIG. 1 and of a side of said machine;
FIG. 9 shows the same machine portion seen in FIG. 7 but according to an opposite view;
FIG. 10 is a part side view of FIG. 9 and shows a further portion of the same side of the machine seen in FIG. 8, this portion being an extension thereof;
FIGS. 11 and 12 are diagrammatic views showing the operation of the machine when traditional workings are carried out;
FIGS. 13 to 18 show new and specific ways of working of the machine according to the invention;
FIG. 19 shows a sequence of working steps in which the steps shown in FIGS. 11 to 18 are combined.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, the knitting machine according to the invention is generally indicated at 1. Summarily, it is provided with a bearing frame 2 having a prevalently horizontal development and supporting a crochet-machine 3 and a jacquard device 4 disposed side by side.
More particularly, the knitting machine according to the invention includes, in a known manner and as particularly seen in FIG. 2, a needle-bar 5 provided with needles 6, a front grooved bar 7, a warp yarn guide bar 8, an under-yarn guide bar 9 and a projection carrier bar 10.
Needles 6 are disposed side by side so that they define a needle lying plane or needle-plane and are axially movable under the action of the needle-bar 5 provided with a reciprocating motion along guides 11 supporting the front grooved bar 7. The role of the latter is to slidably support the needles 6.
The warp yarn guide bar 8 guides the warp yarn 12 and is disposed close to the needle hooks. The warp yarn guide bar 8 is provided with a first oscillating motion parallel to the needle plane 6 and with a second movement of rotation perpendicular to the same plane. The under-yarn guide bar 9, on the contrary, can oscillate parallelly to the needle plane 6 and at right angles to the same plane. Finally, the projection carrier bar 10 is only movable at right angles to the needle plane 6.
In a known manner, rods 13 supporting tubular weft yarn guides 14 are provided, which are disposed side by side on plates 15 that are parallel to the needle-bar 5 and that cross the needle plane 6.
Plates 15, particularly shown in FIGS. 3 and 5, are movable in their own plane in order to define the working oscillations of rods 13. More particularly, plates 15 are movable parallelly to the needle-bar 5 and also according to the predominant direction of development of rods 13.
As shown in the figures, two groups of plates 15 are provided, which have their corresponding rods disposed obliquely with respect to each other and converging towards the needles 6 from an angular position approaching the vertical.
In a known manner too, selection and control members are provided for all the above mentioned active members, which directly contribute to the production of the fabric next to the needles 6.
These members comprise, for example, an oscillating lever 16 which, by means of a tie rod 17 (FIG. 1) controls the movement of plates 15 in a direction parallel to the needle-bar 5, and a column-shaped support 18 (FIG. 2) controlling the vertical motion of plates 15, of the underyarn guide bar 9, as well as of the projection carrier bar 10.
Advantageously the support 18, at its lower portion is provided with a cam follower 19, trapped between a double cam 20, and it is balanced by a support spring 19a that substantially eliminates the weight of the support 18 on the cam follower 19.
The selection and control members also comprise, as shown in FIGS. 7 to 10, hooked needles 21, already known in themselves, a trailing device 22 for said hooked needles 21, needles 23 controlling said hooked needles and a drum 24 for the selection of needles 23 controlling said hooked needles.
The needles 23 that control said hooked needles as well as the drum 24 are already known in the art, but in this embodiment according to the invention they are interconnected and structured in a completely new manner together with the trailing device 22 and the hooked needles 21, as more clearly shown in the following; in addition, they are advantageously located adjacent the plates 15 provided with their corresponding rods 13, in a suitable compartment 2a (FIG. 1) of the bearing frame 2, next to which there is a second compartment 2b accommodating the members seen in FIG. 2.
Summarily, the structure of the knitting machine 1 also comprises feeding devices 25 for the fabric forming yarns 26, not shown in the drawings, as well as conveying devices 27 for the produced fabric, these devices being for example rollers.
More particularly, and referring above all to FIGS. 3 to 6, it can be observed that a fundamental feature of the knitting machine 1 according to the invention is the technical solution concerning rods 13 and their control members.
In fact it is provided that rods 13 are pivotally mounted on pivot pins 28 projecting at right angles from plates 15. The pivot pins 28 engage with rods 13 in a position intermediate the same: therefore each rod oscillates both at its lower end, provided with said tubular weft yarn guides and at its upper end where the kinematic chain controlling the angular position of the same rod is attached. This kinematic chain is carried out in a novel way, by means of a crank 29, of tie rods 30 controlled by said crank 29 and of said hooked needles 21 to which the tie rods 30 are connected. The kinematic chain, as already explained before in short, comprises, beyond the hooked needles 21, a trailing device 22 for the hooked needles 21 as well as needles 23 controlling said hooked needles and a selection drum 24 for said needles 23.
FIGS. 3, 5 and 6 show that the cranks 29 include wheels 29a rotatable about their central axis parallel to pivot pins 28, and pegs 29b projecting from the edge of the wheels 29a. Pegs 29b are introduced into slots 31 obtained in rods 13 and therefore, as shown in FIG. 6, the rotation of wheels 29a constrains the rods 13 to oscillate angularly about the pivot pins 28.
The oscillations of rods 13 are restrained by means of stop means formed by fixed abutments 32 protruding from plates 15 and disposed between the pivot pins 28 and the tubular weft yarn guides 14. Said fixed abutments 32 are symmetrical with respect to the pivot pins 28 and they are spaced from each other so as to allow rods 13 to perform oscillations that lead to maximal linear amplitudes of the tubular weft yarn guides, which corresponds to the double distance between two adjacent needles 6. Furthermore, the oscillations of rods 13 are counteracted by substantially flat-shaped return springs 33 having one of their ends fixed to the rods 13 next to the pivot pins 28, while the other end thereof is free and contacts a fixed projection 34 integral to plates 15. The projection 34 is disposed in line with the axis of rods 13 when the latter are disposed in the middle between two stop members or fixed abutments 32, as shown in FIG. 5.
In a novel way it is provided that each crank 29 should be controlled by two tie rods 30, each of them leading to a specific hooked needle 21. FIG. 3 shows that the two tie rods 30 of each crank 29 are secured by means of a screw 35 to a point of the same crank diametrically opposed with respect to the securing point of peg 29. Wheels 36 placed above each crank 29 ensure the adhesion of tie rods 30 to the same cranks.
Double-acting compensating devices 37 are arranged along the tie rods 30, as seen in FIG. 4. These compensating devices allow each hooked needle 21 to tension the corresponding tie rod 30 so that the corresponding crank can rotate without constraining the other hooked needle connected to the same crank to execute any shifting.
The compensating devices 37 may have different forms: the preferred one, as shown in FIG. 4, consists of a cylindrical body 38 integral to a first damping spring 39 and containing a plunger 40 therein, movable in opposition to a second damping spring 41. Each tie rod 30 engages, at one side of the cylindrical body 38, with the first damping spring 39 and at the other side of the same cylindrical body 38 with the rod 40a of plunger 40. Furthermore, the damping springs 39 and 41 are a pulling spring and a compression spring respectively and they act in opposite directions so as to make the attachment points of the tie rod 30 fundamentally as near as possible.
An important feature of these compensating devices 37 consists in that one of said springs, in this particular case spring 41, has a much lower stiffness than the other, so that it can act as a mere return spring when the device is not under stress.
Each plate 15 is integral to a supporting frame 42 fixed to a specific primary bar 43. Each primary bar 43 is engaged, through connecting pieces 44, with two bars disposed one above the other, in order to give the machine the greatest flexural strength along vertical planes.
Tie rods 30 are introduced in sheaths 45 formed from a tightly coiled wire. These sheaths 45 have a certain flexural strength and are spontaneously arc-connected to a frame 46 provided with horizontal guide channels 47 which extend as far as the hooked needles 21, located in the compartment 2a. Each guide channel 47 contains sheaths 45 that end to two opposed plates 15. Sheaths 45 are connected to supporting frames 42 where they are integral to sleeves 42a that can be disposed, by means of screw means, in the direction of development of the sheaths themselves. The positioning of sleeves 42a causes the shifting of sheaths and consequently the tensioning or releasing of the tie rods 30 (evenness) on wheels 29a, as the tie rods are tightly fitted into sheaths 45. Owing to the high number of sheaths 45 and to the resiliency thereof, the same sheaths exert a remarkable thrust on plates 15 towards the oscillating bar 16 (FIG. 1). Therefore, it is advantageously provided that the sheaths 45 thrust action should be balanced by a first compensating spring 48 acting in the opposite direction and adjustable by means of screw means.
We will now refer to FIGS. 7 to 10, that show the selection and control members accommodated in the compartment 2a and designed to actuate bars 13.
Said selection and control members include, as already mentioned, hooked needles 21, a trailing device 22, needles 23 for the control of said hooked needles, and a drum 24 for the selection of said needles. All these members are already known in themselves but they are arranged in a novel way as the hooked needles have a horizontal development and are held in their resting position by springs 49. Furthermore, the trailing device 22 acts by means of crosspieces or blades 50 disposed transversely to the hooked needles and movable in a horizontal direction. At their edges, blades 50 are integral to a plate 51 movable parallelly to the hooked needles 21 and controlled by a pair of thrust bars 52 actuated by a thrust unit 53. The latter is connected to a drive shaft 54 and, through an eccentric 55, it oscillates guided by two connecting rods 56, one of them being attached to a fixed point 57 and the other to a slider 58 integral to the thrust bars 52.
In order to balance the action of springs 49 on the thurst unit 53, a second compensating spring 59 is provided counteracting the action of springs 49. The second compensating spring 59 is inserted between the plate 51 and an envelope 60 integral to the bearing frame 2.
As shown in FIGS. 7 and 9, needles 23 for the control of said hooked needles are substantially vertical and, at their upper ends provided with bent portions 61, they are hung up to a cross bar 62.
The bent portions 61 of the needles 23 controlling said hooked needles are opened so as to allow the lifting of the same needles in opposition to an upper pressing plate 63 which, together with a lower plate 64, "closes in a pack" the needles 23 for the control of said hooked needles. Said plates are centrally connected to each other and reciprocally integral by means of a vertical bar 65 adapted to be lifted at the inside of an envelope 60 in opposition to spring means 66.
The lower plate 64 is provided with a hole so as to allow the passage of needles 23 when it is lifted together with the vertical bar 65 and the upper plate 63. However, the cross bar 62 is not lifted together with the above members and needles 23 keep their hooked position with respect to the same cross bar 62.
The lifting of needles 23 controlling said hooked needles, together with plates 63 and 64 and with the vertical bar 65 is eventually controlled by drum 24 which can be raised so that one of the faces thereof can contact the lower plate 64 and lift the same. The drum 24 is combined, in a known manner, with cards 67 having a series of perforations, for conveying instructions to the knitting machine. The presence or absence of said perforations establishes the position of the needles 23 controlling said hooked needles and therefore the position of the same hooked needles 21 and of rods 13 connected thereto by means of the tie rods 30. The programming of the machine by means of the punched cards 67 is known in itself and therefore it will not be further explained.
However it should be observed that the working motion of drum 24 in the knitting machine according to the invention can be controlled in a very simple and precise manner. In fact, at one side of drum 24 a first disc 68 is provided (FIGS. 9 and 10) having first front projections 69 that, when the drum 24 is raised, are inserted into vertical elongated apertures 70 obtained on the fixed envelope 60. The lifting motion is independent of the movement of rotation and the first one is controlled, close to each side cover of the knitting machine according to the invention, by a forked lever 71 slidably engaging the main shaft 72 of drum 24 in a direction parallel to its own axis of development. The engagement between the forked lever 71 and the main shaft 72 occurs by means of a joining ring 73 rotatable with respect to the main shaft 72 and provided with chamfered portions, so that the flat surfaces thereof can contact the forked lever 71. Each forked lever 71 is controlled by the drive shaft 54 by means of a further lever 74.
The movement of rotation of drum 24 is, on the contrary, controlled by a connecting rod 75 connected to a crank 76 fitted at one end of the drive shaft 54, as shown in FIGS. 7 and 8. The connecting rod 75 is pivotally mounted on one end of a rocker 77 slidably engaging, by means of a fork-shaped lug, the second front abutments 79 of a second disc 80 that is secured on the main shaft 72 at the opposite side with respect to the first disc 68.
As shown in FIGS. 7 and 8, the connecting rod 75 is provided at its ends with ball joints 81 and the rocker 77 is movable in a direction away from the second disc 70 by action of a hand control lever 82 integral to a cam 83 working in direction of the rocker 77. The latter is provided with an axially slidable articulated member 84 which allows the rocker 77 to be spaced apart from the second disc 80.
After what has been described above, the operation of the different mechanical members of the weaving machine according to the invention appears evident due to the simplicity of the same members and to the fact that many remarks concerning the operation of said machine have already been made for the sake of clearness, during the above description.
On the contrary, the different working possibilities of this machine depending upon the above described structure are clearly explained in FIGS. 11 to 19.
In these figures the following members are diagrammatically shown: tubular weft yarn guides 7, rods 13, plates 15, the front grooved bar 7, needles 6, the warp yarn 12 and the weft yarn 85 that is supplied through the tubular weft yarn guides 14. Furthermore, the oscillations of plates 15 are indicated by the arrow 86 and it is understood that these oscillations are of a known type, i.e. they have the same amplitude than the distance between two adjacent needles 6.
Above all, it must be pointed out that the knitting machine according to the invention can behave like a common knitting machine of the known type. In fact, as shown in FIGS. 11 and 12, when rods 13 keep their intermediate vertical position between the maximal oscillations thereof, the weft yarn 85 can be formed into loops in correspondence of a single needle.
Furthermore and in a novel way, the machine can make no loops and therefore deactivate the action of the jacquard device when the angular oscillations take place, as shown in FIGS. 15 and 16, in the opposite direction with respect to the shiftings of plates 15 and over a way corresponding to the distance between two needles 6.
On the contrary, if angular oscillations of rods 13 in the same direction than the shiftings of plates 15 are utilized, it is possible to obtain two loops, as shown in FIGS. 13 and 14, or even three loops, as shown in FIGS. 17 and 18. The obtention of three loops is possible when rods 13 start from a shifted position that therefore does not coincide with the intermediate one.
FIG. 19 shows, by way of example only, how all the movements shown in FIGS. 11 to 18 can be combined together: practically, it is already possible to create patterns between the warp yarns by means of a single rod 13.
The invention attains the intended objects. The knitting machine thus obtained is suitable to carry out all kinds of figured fabrics by simply changing the program controlling the machine operation, by means of the selection drum 24, but it also exhibits a simple structure, a balanced operation and reduced dimensions particularly as to its height.
Though the machine is fundamentally novel, it can easily be utilized by operators skilled in the pre-existent knitting machines and all the different members thereof can be readily replaced or eliminated. By the hand control lever 82 it is also possible a hand control of drum 24.
The embodiment of the invention described above is not intended to comprise a limitation and modifications can be carried out within the scope of the following claims. Furthermore, all details can be replaced by technically equivalent elements. Practically the materials, shapes and sizes can be whatever according to the requirements. | The invention particularly relates to an improved knitting machine to produce figured fabrics.
The knitting machine has high working capacity and is capable of producing various patterned and colored fabrics. This improved knitting machine comprising rods suitable to support tubular weft yarn guides disposed side by side on plates parallel to the needle bar and transversely to the needle plane, the plates being movable along their own plane and parallelly to the needle bar in order to define the working oscillations of the rods, and characterized in that the rods are rotatably supported by pivot pins that are fixedly engaged with the plates, the pivot pins protruding at right angles from the same plates, in that it is provided with stop members for the rods designed to allow the same to oscillate symmetrically with respect to vertical planes and to cause the maximal linear amplitude of the tubular weft yarn guides which corresponds to the double distance of two needles in succession, and in that selection and control members are provided which include a plurality of kinematic chains suitable to position each of the rods angularly and independently of the adjacent rods. | 3 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is the US National Stage of International Application No. PCT/EP2005/054941, filed Sep. 30, 2005 and claims the benefit thereof. The International Application claims the benefits of European application No. 04024184.6 EP filed Oct. 11, 2004, both of the applications are incorporated by reference herein in their entirety.
FIELD OF INVENTION
The invention relates to a method for operating a burner, in which a fuel is supplied to the burner, sprayed into the combustion air and mixed with the combustion air into a fuel/air mixture and burned in a combustion chamber.
BACKGROUND OF THE INVENTION
In the light of international efforts for reduce pollutant emissions from heating systems, particularly gas turbines, burners and methods of operation for burners have been developed in recent years which have particularly low nitrous oxide (NO x ) emissions. In such cases emphasis has frequently been placed on the fact that such burners are able to be operated not just with one fuel but where possible with a wide variety of fuels, for example oil, natural gas and/or synthetic gas (e.g. coal gas) as required or even in combination in order to increase security of supply and flexibility during operation. Such burners are described for example in EP 0 276 696 B1.
An associated problem is that of a stable combustion in the burner, which is based on a stable location of the combustion zone in the burner. This alters drastically if changes occur in the composition of the fuel, meaning for example a combustion gas having a high proportion of high-grade saturated hydrocarbons, such as C 2+ alkane, ethane or propane. Under such circumstances there is a danger of flame blowbacks in the burner. Patent WO 03/062618 A1 thus in particular monitors the C 2+ alkane of the inflow combustion gas through infrared absorption. To avoid a blowback, with an increased proportion of C 2+ alkane, the combustion gas characteristic is regulated by intervening for example in the combustion gas supply, but also by injecting water or steam.
The problem in designing burners for all possible different operating conditions and fuels, especially when there is also a variation in the fuel composition or if there are fluctuations in fuel quality, lies in the fact that the volumes needed during operation in each case (fuel mass flow) of the individual fuels are completely different, making it difficult to use the same supply system and the same spray openings for all fuels. The use of different supply systems for liquid and gaseous materials is thus known in the prior art. A further problem then presents itself however if alternate gaseous fuels with entirely different specific calorific values, for example natural gas and coal gas, are to be used. The completely different volume ratios when using these two fuels and the different chemical processes during their combustion demand a modification and expansion of the known systems.
Modern low-NO x combustion systems are usually based on the so-called “jet in crossflow” mixing-in concept. Low-pollutant combustion, especially with low NO x emissions, can in this case be undertaken by corresponding designs of the mixing-in of the fuel into the cross-flow combustion air. An important design variable in such cases is the penetration depth of the fuel jets into the cross-flow air. This mechanical design adapted in the best possible manner is then correspondingly only used for a specific fuel composition. The invention now uses as its starting point the problem that, with a temporary alteration to the fuel composition or if the fuel is changed, the result can be an alteration of the mixing field, which, with an unfavorable mixture, usually leads to increased NO x emissions.
Based on this observation, an object of the invention is to specify a method for operation of a burner with which a low nitrous oxide combustion is possible even if there is a change to the fuel composition. A further object of the invention is to specify a suitable device for executing the method.
The first object is achieved in accordance with the invention by a method for operation of a burner, in which a fuel is supplied to the burner, sprayed into the combustion air and mixed with the combustion air into a fuel/air mixture and burned in a combustion chamber, in which case, to reduce the nitrous oxide emissions, a fuel characteristic is set explicitly to a predetermined nitrous oxide emission, with a change in a parameter characterizing the fuel being determined and with a penetration depth of the fuel jets into the combustion air adapted to the change being effected.
In this case the invention starts from the knowledge that the influence of fuel composition fluctuations on the NO x emissions should if possible not be compensated for by expensive burner-side measures or by expensive adaptations to the mechanical design in the combustion chamber, in order to achieve sufficient flexibility and timely adaptation to the predetermined nitrous oxide emissions. Constructive measures could only reduce the sensitivity to fluctuations in fuel quality—and thereby mixing field variations—to a limited extent, but could not eliminate them completely. This is attributable to the fact that, for a quite specific fuel composition in each case (fuel characteristic) the injection and mixing-in facilities of the burner are “optimized”. Designs with a plurality of injection spray points for the fuel—well distributed over the cross section through which the flow is conducted—or the use of static mixers for setting a desired mixture field, in the absence of the required flexibility—especially with shorter-term variations in fuel composition—are not suitable for guaranteeing compliance with permitted emission limits for NO x emission during operation of the burner or of the combustion system. On the other hand the invention starts from the knowledge that, by spraying the fuel into the combustion air with a most favorable possible penetration level of the fuel jets, the mixing field will be adjusted in respect of a low-emission combustion. This mixing field can even be maintained during operation, taking into account the parameter characterizing the fuel.
Thus the invention proposes for the first time achieving an especially low nitrous oxide combustion by monitoring the fuel characteristic of the fuel composition, in order, if required, to use suitable measures to once again set an optimum low-pollutant operating mode as regards nitrous oxide if a parameter characterizing the fuel changes. This creates the opportunity of keeping the nitrous oxide emissions below a predetermined limit using a parameter which characterizes the fuel, with a penetration depth of the fuel jets adapted to the change being effected in the combustion air.
Preferably in this case the fuel is sprayed into the combustion air and mixed with the combustion air. Fuel and combustion air are mixed in the burner, with the best possible penetration depth of the fuel rays into the combustion air having to be ensured for the injection of the fuel into the combustion air. This means that the mixing field can be adjusted in respect of a low-pollutant combustion and can be maintained even during operation taking into account the parameter characterizing the fuel.
In an especially preferred embodiment a change in the parameter characterizing the fuel is registered and transferred to a control system. In this case the parameter characterizing the fuel is preferably continuously detected and evaluated in the control system. The parameter characterizing the fuel can in this case be determined by a suitable measurement of the fuel flow during operation and in this way the timing of the parameter characterizing the fuel can be stored and evaluated.
Preferably the fuel characteristic is set explicitly, with the value being set to a reference or required value of the parameter characterizing the fuel at which the predetermined pollutant emission occurs. In this case characteristic performance data determined in advance can already be stored in the control system, with said data representing the relationship between the fuel composition and the nitrous oxide emissions. Alternatively however an in-situ measurement of both the current nitrous oxide emission values and also the fuel composition is simultaneously measured and transferred to the control system.
In an especially preferred embodiment the Wobbe index is determined from a parameter characterizing the fuel. What is referred to as the Wobbe index is a normal standard used to characterize the fuel composition and temperature. The Wobbe index allows a comparison of the heat content of different fuels relative to their volume, especially combustion gases, to be made at different temperatures. Since a combustion system, such as a gas turbine for example, is operated such that in the final analysis heat energy is released in a combustion chamber and that the fuel flow is set by controlling the volume flow, fuels with different fuel composition but still with relatively similar Wobbe indexes are generally supplied by the same fuel supply system to the burner. Variations in the fuel composition lead to variations in the nitrous oxide emissions, with a setting of the Wobbe index enabling a permitted highest nitrous oxide emissions in the operation of the gas turbine.
In the inventive method the Wobbe index of the fuel is preferably determined by evaluating
the relationship
W I = L H V S G · T / T Ref ,
with LHV being the lower heat value of the fuel, T its absolute temperature and SG the specific gravity of the fuel relative to the air under standard conditions, and T Ref being a reference temperature.
In this case, for setting the desired Wobbe index, the temperature of the fuel is preferably set explicitly with respect to a predetermined nitrous oxide emission. According to the above formula the Wobbe index is related in a relatively simple manner to the current fuel temperature, namely inversely proportional to the square root of the fuel temperature. This means that, if the Wobbe index changes, i.e. the Wobbe index deviates from a predetermined required value with low nitrous oxide emissions, the desired Wobbe index and thereby the desired nitrous oxide emission can be set by a corresponding regulation of the fuel temperature. Depending on the situation the fuel can be warmed up or cooled down to the required value to enable a temperature setting of the required value of the Wobbe index to be used to achieve the desired NO x emission.
It is however also possible for a medium to be mixed in with the fuel for setting the fuel characteristic. A modification of the Wobbe index is also especially to be achieved in this way in order to ensure a low-pollution operation of the burner. The preferred medium considered for injection into the fuel is water, steam or nitrogen, but also hydrocarbons with a high heat value for example.
As an alternative to the Wobbe index, the so-called impulse flow density ratio can also be determined and evaluated as a parameter characterizing the operating state. Impulse flow density ratio: The mixture quality with “jet in crossflow” depends, with a given geometry, on the impulse flow density ratio, i.e. on the quotient of the impulse flow density ratio of the jet and on the impulse flow density ratio of the crossflow.
Impulse I=M·c=p·c·A·c
Impulse density I=I/A (surface)= pc 2
Impulse flow density of the air is essentially given by ambient conditions and gas turbine performance. Impulse flow density of the fuel, apart from depending on the gas turbine performance also only depends on the fuel composition. The heating value gives the mass flow and thereby with the density for fixed geometry the impulse flow density. The impulse flow density is thus not a fuel characteristic but a variable which depends on the fuel composition. This variable can also be regulated to a desired required value if it changes by monitoring the fuel composition during the operation of the burner.
Preferably the method is applied when a burner of a gas turbine is operated. The demands for low-pollutant combustion during operation of gas turbines, especially with stationary gas turbines for energy production, have increased continuously in recent years. The method In accordance with the invention makes low-emission operation possible, with the regulation measures described above already being able to be undertaken on the fuel side during the operation of the gas turbine system if there are variations in the composition of the fuel. Expensive constructive measures on the burner side can be dispensed with.
A liquid or gaseous fuel is preferably used for operation. The method can be used example with oil, natural gas or with a synthetic gas, e.g. coal gas.
An object of the invention directed to a device is achieved by a device for carrying out the method with an analysis device for analysis of the current fuel composition during burner operation and with a checking and control system for determining a deviation and for setting the parameter characterizing a fuel to a required value, at which the predetermined pollutant emission is present.
The advantages of the inventive device are produced in the same way as the above-described advantages relating to the method.
The checking and control system is preferably designed in this case for setting the fuel temperature of the fuel, i.e. a heating up or cooling down the fuel as required.
The checking and control system also preferably includes means for controlled injection of an inert medium, especially steam, water or nitrogen or of a hydrocarbon, into the fuel.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be explained in greater detail below with reference to an exemplary embodiment. The diagrams are schematic and not to scale:
FIG. 1 a gas turbine system,
FIG. 2 a schematic diagram of a fuel processing device for low nitrous oxide operation of the gas turbine system in accordance with FIG. 1 and
FIG. 3 a schematic diagram showing the relationship of the Wobbe index as a function of the combustion gas temperature for different fuel compositions.
The same reference symbols have the same meaning in the figures.
DETAILED DESCRIPTION OF INVENTION
A gas turbine system in accordance with FIG. 1 has a gas turbine 1 which has a compressor 3 , a combustion chamber 9 and also a turbine 17 downstream of the combustion chamber 9 . The compressor 3 and the turbine 17 are if necessary coupled to each other via a common rotor shaft 5 . Connected downstream from the turbine 17 is an electrical generator 19 for example, coupled via a generator shaft 25 to the turbine 17 . The combustion chamber 9 comprises a combustion area 11 as well as a burner 13 protruding into the combustion area 11 for combustion of a liquid or of a gaseous fuel 15 . During operation of the gas turbine 1 air 7 is sucked into the compressor 3 and compressed there. The compressed air 7 is supplied to the burner 13 as combustion air and mixed with fuel 15 . The fuel/air mixture produced by this process is burned in the combustion chamber 11 , producing hot combustion gases. The hot combustion gases are supplied to the turbine 17 , where they expand to generate work and cause both the compressor-side rotor shaft 5 and also the generator shaft 25 to rotate. In this way electrical power is created, which the generator 19 outputs for distribution in an electrical network. On the downstream side of the turbine 17 the partly cooled and expanded combustion gases are output as exhaust gas 21 . These exhaust gases 21 are polluted, in particular nitrous oxide is present in the exhaust gas which forms at the high combustion temperatures in the combustion area 11 . Increased nitrous oxide emissions also occur if the fuel/air mixture undergoes a change of the mixing field, as occurs for example when the fuel composition alters over time or when the fuel is to be changed for example. This generally leads to a less favorable mixture and to a considerable increase in the rate of nitrous oxide formation during the combustion processes. Previous measures from the prior art have merely been restricted in such cases to making new adaptations to the design of the combustion system, i.e. burner-side measures to enable pollutant emissions which are still acceptable when the composition of the fuel changes.
The invention by contrast does not provide for any measures for changing the design of the burner in order to resolve this problem, but instead explicitly influences the fuel characteristics during operation in order to adhere to the predetermined nitrous oxide emissions as an upper limit value. To this end the gas turbine 1 is equipped in the supply system for the fuel 15 with a fuel processing device 23 , with said device 23 allowing both an analysis of the current fuel characteristic in the operation of the gas turbine 1 and also an explicit setting of a fuel characteristic in respect of the predetermined nitrous oxide emission for reducing nitrous oxides. In this way a change in a parameter characterizing the fuel 15 is determined and monitored. Furthermore the penetration depth of the fuel jets into the combustion air is adapted to the change.
FIG. 2 shows a greatly simplified diagram of the fuel processing device 23 . The device 23 includes an analysis device 27 for the fuel 15 and a checking and control system 29 connected downstream from the analysis device 27 . To explicitly monitor a fuel characteristic an analysis partial flow 31 is separated for example from the volume flow of the fuel 15 and supplied to the analysis device 27 for analysis purposes. The analysis of the fuel composition is undertaken in the analysis device 27 . In this case a parameter characterizing the fuel 15 , such as the Wobbe index for example, which has direct influence on the current nitrous oxide emission, is determined and this value is passed as an output signal 33 to the checking and control system 29 . When this is done, the parameter characterizing the fuel 15 is continuously detected in the analysis device 27 and evaluated in the checking and control system 29 . The required value is compared to the actual value in the checking and control system and the fuel characteristic is explicitly set so that the setting or regulation is made to the reference or required value of the parameter characterizing the fuel in which the predetermined nitrous oxide emission is present. The Wobbe index WI (see FIG. 3 ) is particularly suitable for use as the parameter characterizing the fuel 15 . This can be regulated directly via a setting of the combustion temperature T in order to reach a desired value. A required correction of the Wobbe index WI if a deviation from the required value is established can alternatively also be achieved by injection of a medium into the fuel. Steam, water or nitrogen are considered as a suitable inert medium for use in regulating the Wobbe index WI to the required value. The impulse flow density ratio can alternatively also be determined and evaluated as a possible parameter. The fuel processing device 23 makes possible an in-situ regulation of a parameter characterizing the fuel as regards the lowest possible nitrous oxide emissions. The fuel 15 handled in this way in the fuel processing device 23 will then be fed to the burner 13 , mixed with combustion air 7 to a fuel/air mixture internally and burned in the combustion area 11 as already described in detail above.
The Wobbe index WI is especially characteristic for the current fuel composition. The Wobbe index WI has a simple relationship to the fuel temperature T, as explained in greater detail in FIG. 3 . FIG. 3 shows a diagram in which, for different fuel compositions, the dependency of the Wobbe index WI as a function of fuel temperature T is shown. Characteristic curves K 1 , K 2 and K 3 represent a particular fuel composition in each case. The Wobbe index WI is inversely proportional to the square root of the fuel temperature T. Since the Wobbe index characterizes the fuel composition, the Wobbe index WI can also be seen in conjunction with the relevant nitrous oxide emissions in the operation of a gas turbine 1 . There is thus an “optimum” value for the Wobbe index WI SOL , in which correspondingly lower nitrous oxide emissions are to be recorded. For a change of the fuel composition during operation of the gas turbine 1 the effect is thus to produce a change in the Wobbe index WI. This can be established by means of the analysis device 27 . Using a setting of the fuel temperature T, the Wobbe index WI at the temperature T OPT (K 2 ) can be set back to the required value of the Wobbe index WI SOL , so that a desired value of nitrous oxide emissions is not exceeded.
The invention proposes changing the penetration depth of the fuel jets and thereby changing and correcting the mixing field through different measures during the operation of the gas turbine, if the composition of the fuel changes. To this end it is proposed that a parameter characterizing the fuel be monitored and set in respect of the desired nitrous oxide emission. The change in the fuel composition is passed to a checking and control system, either as a manual entry or via a measurement and analysis system 27 integrated into the control system which continuously measures the fuel composition. A suitable measure can be taken via a suitable conversion specification—for example by regulating the Wobbe index. Options are for example the change of the fuel temperature through preheating or reducing a fuel preheating, the admixture of steam, nitrogen or such like, or water to liquid fuels such as heating oil. A directly suitable variable for description of the corresponding fuel characteristic is the Wobbe index, for which, although there are different definitions, all of these can be related back to the fact that media with the same Wobbe index cause the same pressure loss at the fuel nozzle with the same heat input. The penetration depth of the fuel jets into the combustion air is linked to the pressure loss, so that the use and setting of a parameter characterizing the fuel such as the Wobbe number represents a relatively simple conversion specification for regulation to the desired nitrous oxide emission for variations of the fuel composition. Other adjustment variables, such as the impulse flow density ratio for example, are also conceivable. | There is described a method for operation of a burner, whereby a fuel is supplied to the burner, sprayed into the combustion air, mixed with the combustion air to give a fuel/air mixture and burnt in a combustion chamber. With regard to a combustion particularly low in pollutants and, in order to reduce the nitrogen oxide emissions with relation to achieving a given nitrogen oxide emission level, a change in parameters characterizing the fuel is determined. Such a parameter may, for example, be the Wobbe index. There is further described a device for carrying out said method, comprising a fuel treatment device, with an analytical device for the analysis of the current fuel composition and a monitoring and control system. | 5 |
BACKGROUND OF THE INVENTION
Field of the Invention
The invention concerns a method for operating a motorized actuating device for a movable vehicle part. The invention also concerns an associated actuating device for adjusting the vehicle part. The vehicle part to be adjusted is in particular a vehicle window pane, the actuating device being in particular an electric motor window lifter.
Precise adjustment of the actuating position is often necessary or at least desirable with a motorized movable vehicle part. Thus inaccurate positioning of a vehicle window pane is a significant disadvantage for example for the so-called short-stroke function with which the window pane is moved away from the upper door seal of a frameless vehicle door in order to enable resistance-free opening of the vehicle door. Narrow limits are often set for the short stroke movement by the vehicle manufacturer. This ensures that on the one hand the window pane is fully moved away from the window seal, but that on the other hand the window pane is not too far open following the short stroke, since otherwise according to the applicable legal requirements for returning the window pane sometimes additional safety provisions such as for example an automatic anti-trapping means are required.
A precise approach is however also desirable for other actuating positions of a window pane, in particular when approaching the lower or upper preliminary switching point, at which the window pane is usually stopped shortly before it actually reaches the (lower or upper) blocking condition. Moreover, precise positioning of a window pane is also desirable for example during the approach to the so-called RELAN (Relax After Normalization) point. The window pane position to which the window pane is frequently returned to relieve the load on the actuating mechanism following an adjustment movement to the lower or upper blocking condition is referred to as the RELAN point.
Precise adjustment of the actuating position is also desirable for other special window pane positions (for example an automatically adjusted “smoking gap”) for aesthetic reasons. In addition, a precise actuating position setting is also advantageous for other actuating devices in a vehicle, in particular seat adjusters, door and hood adjusters, etc.
BRIEF SUMMARY OF THE INVENTION
The object of the invention is to ensure particularly precise adjustment of the actuating position of the vehicle part to be adjusted for an actuating device of the aforementioned type with a simple means.
Regarding a method for operating a motorized actuating device for a movable vehicle part, the object is achieved according to the invention by the claimed features. Regarding the actuating device, the object is achieved according to the invention by the claimed features. Regarding a control unit for activating the electric motor of an actuating device and regarding a computer program product—provided for implementation in such a control unit—the above object is further achieved according to the invention by the claimed features. Embodiments and developments of the invention that are advantageous and partly inventive in themselves are set out in the dependent claims and the subsequent description. The vehicle part to be adjusted is also referred to below as an “actuating element”.
According to the method, the actuating motor of the actuating device is stopped during an actuation process at a predetermined lead prior to reaching a target position of the actuating element—by switching off the electrical operating voltage that is fed to it. Thus in other words the actuating motor is already switched off at a point in time at which the actuating element is still at the distance of the lead from its target position.
The term “lead” thus refers to the actuating displacement interval by which the stopping point (switch-off position) of the actuating motor differs from the desired target position of the actuating element. The magnitude of the lead can optionally be related here to the actual actuation distance covered by the actuating element and—in the case of a window pane to be adjusted—can thus be specified in units of millimeters or centimeters of the pane displacement for example. Alternatively, the lead can also be expressed in units of a variable that has a definite (linear or non-linear) relationship to the travelled actuation distance of the actuating element. Thus within the scope of the invention the lead can for example also be specified in relation to the rotation angle by which the motor shaft of the actuating motor rotates to achieve the corresponding feed of the actuating element (for example by the number of quarter revolutions the motor shaft). With another alternative, the lead can also be specified within the scope of the invention in relation to the period of time required for the actuating motor to adjust the actuating element by the appropriate actuation distance interval.
According to the invention, the lead is not predetermined as a fixed value. Rather, on the one hand the lead is varied depending on the revolution rate of the motor or on an actuation rate measurement variable correlated therewith. On the other hand, according to the invention the lead is also varied depending on a temperature measurement variable that is characteristic of the ambient temperature of the actuating device.
A variable that has a definite (linear or not-linear) functional relationship to the revolution rate of the motor is referred to here as an “actuation rate measurement variable”. Within the scope of the invention, in particular the measured battery voltage of the vehicle is used as an indirect “actuation rate measurement variable”, which determines the value of the operating voltage for the motor and hence the revolution rate of the motor. Within the scope of the method according to the invention, the “temperature measurement variable” can optionally specify the external temperature in the surroundings of the vehicle, the temperature in the interior of the vehicle or for example the temperature of a vehicle part. Instead of a direct temperature specification, within the scope of the invention the temperature measurement variable can also be a variable with a definite (linear or non-linear) functional relationship to the measured temperature.
The invention is based on the consideration that inaccuracies in the actuation position adjustment are primarily caused by the fact that the actuating motor and the actuating element do not stop instantaneously with the switch-off of the operating voltage, but initially continue to move because of their mechanical inertia. Said further movement is below as “overrun” and is intended to be optimally compensated by the lead provided according to the method.
It is known that the overrun essentially depends on the revolution rate of the actuating motor and the kinetic energy caused thereby. As a rule the overrun is thus generally the greater, the faster the actuating motor rotates to the stopping point (switch-off point in time).
However, it is known that taking into account the revolution rate of the motor alone is not sufficient to accurately predict the end position at which the actuating element actually comes to rest following the switch-off of the actuating motor. Rather, said end position also depends on the mechanical play of the actuating device and the actuating resistance opposing the displacement of the actuating element. It has been shown here that the latter two influences can be simply yet precisely taken into account within the scope of the invention by means of an—empirically determinable—temperature dependency of the lead. The method according to the invention is thus characterized by high precision in the adjustment of a desired target position, but is particularly easy to implement at the same time.
In an advantageous development of the invention, the actuation direction in which the actuating element is moving is taken into account in addition to the revolution rate of the motor (or other actuation rate measurement variable) and the temperature measurement variable. This takes into account the fact that the overrun of the actuating element is in practice also partly significantly dependent on the direction of the actuation movement. It is known that this concerns to a significant extent actuating devices for actuating elements whose actuation path is oriented exactly vertically or at least has a vertical component of motion. This also includes, besides window lifters, for example actuating devices for automatically opening vehicle trunk lids, backrests, etc. In addition, the displacement of the actuating element following the switch-off of the actuating motor is also influenced here by the dead weight of the actuating element. Thus when raising the actuating element work has to be done against the dead weight of the actuating element. The actuating element only has a small tendency to overrun in this case, since the mechanical inertia of the actuating element is wholly or partly compensated by the opposing gravitational force. When lowering the actuating element, by contrast the mechanical inertia and the gravitational force of the actuating element act in the same direction, so that the overrun of the actuating element is frequently significantly greater in this case.
It is known that the actuation direction-dependent tendency to overrun correlates strongly with the temperature dependency of the overrun. With a window pane for example, it is significant that the running resistance of the window pane is strongly influenced by the window seal and reduces significantly with increasing temperature of the seal.
In one version of the method that is aimed at the adjustment of a (exactly or partly) vertically movable actuating element, it is provided that when lowering the actuating element the lead is increased by a correction factor compared to the lead value that is provided for lifting—under otherwise identical conditions. The correction factor is variably amended here depending on the temperature measurement.
The actuating device comprises an electrical actuating motor, an actuating mechanism as well as a control unit. The actuating mechanism is used here for drive technology coupling of the actuating motor to the actuating element. The control unit is again used for activating the actuating motor.
According to the invention, the control unit is configured here in terms of programming and/or circuitry for the automatic performance of the method according to the invention, in particular in one of the embodiment versions described above. In a preferred embodiment, the control unit is formed by a microcontroller, at least in its core, in which the method according to the invention is programmatically implemented in the form of operating software (firmware), so that the method is automatically performed when executing the operating software in the microcontroller. Alternatively however, for this purpose the control unit can also be formed within the scope of the invention by a (non-programmable) hardware circuit, in which the functionality for automatically performing the method is implemented in circuitry.
Embodiments of the invention are also a control unit of the aforementioned type as such, i.e. without the other components of the actuating device and a computer program product.
According to the invention, the control unit is—as described above—configured in circuitry terms and/or programmatically to automatically perform the method according to the invention, in particular in one of the embodiment versions described above.
The computer program product comprises computer-readable instructions, with the execution of which the method according to the invention is automatically performed, in particular in one of the embodiment versions described above. The computer program product is designed in this case for execution in the control unit of a motorized actuating device of the aforementioned type, wherein the control unit is formed by or at least comprises a microcontroller for this.
The actuating device is preferably an electric motor window lifter for adjusting a vehicle window pane. The invention is in principle also applicable to other motorized vehicle actuating devices, for example to a seat adjuster, a door adjuster or a roof adjuster.
For requesting the temperature measurement variable, in particular a value of the external or internal temperature, the control unit can preferably be coupled to the central on-board electronics, in particular the on-board computer of the vehicle. Alternatively, within the scope of the invention the actuating device can also comprise a dedicated temperature sensor for this purpose that directly ascertains the temperature measurement variable and feeds it to the control unit.
The method according to the invention is intended for use in particular when approaching the short-stroke position of the window lifter. The method is also advantageous for the adjustment of other specified actuating positions, in particular for actuating positions that can be approached from both actuating directions.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
An exemplary embodiment of the invention is explained in detail below using figures. In the figures:
FIG. 1 shows in a schematic representation a window lifter with an electrical actuating motor, an actuating mechanism, by means of which the actuating motor is coupled to a (vehicle) window pane, as well as to a control unit for activating the actuating motor,
FIG. 2 shows, in a schematic diagram against the revolution rate of the actuating motor, a revolution rate-dependent base term of a lead by which the control unit stops the actuating motor before reaching the target position,
FIG. 3 shows, in a schematic diagram against the external temperature of the vehicle, a temperature-dependent correction term by which the control unit increases the lead when lowering the window pane,
FIG. 4 shows, in a schematic diagram against time, the profile of the physical actuating position of the window pane (solid line) in comparison with a logical actuating position proportional to the number of revolutions of the motor (dashed line) when lifting the window pane, and
FIG. 5 shows the physical actuating position and the logical actuating position when lowering the window pane in a representation according to FIG. 4 .
DESCRIPTION OF THE INVENTION
Mutually corresponding parts and variables are always provided with the same reference characters in all figures.
FIG. 1 shows schematically an actuating device in the form of a window lifter 1 for a (vehicle) window pane 2 of a motor vehicle.
The window lifter 1 comprises an electrical actuating motor 3 that is mechanically coupled by means of an actuating mechanism 4 to the window pane 2 such that the window pane 2 can be reversibly displaced by the actuating motor 3 along an actuation path 5 between two end positions, namely an open position 6 and a closed position 7 .
FIG. 1 shows the window pane 2 in the open position 6 and the closed position 7 with dashed contour lines in each case. The window pane 2 is shown with a solid contour line in an actuating position x between the two end positions. The actuating position x has for example the value zero if the window pane 2 is in the open position 6 .
The actuating mechanism 4 comprises a drive worm 9 attached to a motor shaft 8 of the actuating motor 3 , which meshes with a worm wheel 10 . The actuating mechanism 4 also comprises further components (not shown in detail), for example a control cable, by means of which the worm wheel 10 is coupled to the window pane 2 .
The actuating device 1 also comprises a control unit 12 in the form of a microcontroller as well as an angular position sensor 13 . The angular position sensor 13 comprises a multi-pole ring magnet that is rotationally fixedly attached to the motor shaft 8 as well as a Hall sensor working in conjunction with the ring magnet. During the operation of the actuating motor 3 , the ring magnet rotating together with the motor shaft 8 relative to the Hall sensor generates in conjunction with the Hall sensor a periodically oscillating pulse signal S H that is fed to the control unit 12 by the angular position sensor 13 as an input variable.
During the running actuation process the control unit 12 calculates a variable, which is referred to below as the rotation angle, that is proportional to the number of revolutions of the motor shaft 8 by counting the (Hall) pulses of the pulse signal S H . By summing the rotation angle with a stored initial value, the control unit 12 calculates a time-dependent logical actuating position of the window pane 2 , which is referred to below as the actuating position measurement x′. In addition to the actuating position measurement x′, the control unit 12 calculates the revolution rate n of the motor shaft 8 by counting the pulses of the control signal S H per time unit or by measuring the interpulse times.
A (temperature) measurement value T is also fed to the control unit 12 that is characteristic of the ambient temperature of the window lifter 1 (in this case the external temperature of the vehicle). In the example shown the temperature measurement value T is detected by a temperature sensor 14 associated with the window lifter 1 . Alternatively, the temperature measurement value T can also be obtained by central on-board electronics of the motor vehicle.
The control unit 12 controls the actuating motor 3 by applying an electrical operating voltage U M (motor voltage). For its part the control unit 12 is supplied with an electrical battery voltage U B by a vehicle battery.
In order to prevent the window pane 2 from running past a target position x Z ( FIG. 4,5 ) to be set because of the mechanical inertia of the overall system formed by the window lifter 1 and the window pane 2 during an actuation process, the control unit 12 stops the actuating motor 3 (by switching off the operating voltage U M ) before the window pane 2 has actually reached the target position x Z . The actuating position measurement x′ at which the control unit 12 switches off the actuating motor 3 is referred to for this as the switch-off position x′ A ( FIG. 4,5 ). The switch-off position x′ A is given here by subtracting a predetermined lead x V ( FIG. 4,5 ) from the target position x Z :
x′ A =x Z −sx V
By multiplying the lead x V by a direction variable s, which has the value +1 when lifting the window pane 2 and has the value −1 when lowering the window pane 2 , it is ensured in the above equation that the lead x V is regarded as negative when lowering.
The control unit 12 variably determines the lead x V from a revolution rate-dependent base term D (D=D(n)) and a temperature-dependent correction term K (K=K(T)). The control unit 12 additionally takes the actuation direction into account during the determination of the lead x V by only using the correction term K when lowering the window pane 2 . By contrast, when lifting the window pane 2 the control unit 12 determines the lead x V exclusively from the base term D:—
x
v
=
{
D
(
n
)
lifting
D
(
n
)
+
K
(
T
)
lowering
The control unit 12 thus selects the lead x V —under otherwise corresponding conditions, i.e. for the same values of the revolution rate n and the temperature measurement variable T—to be greater by a correction term K when lowering the window pane 2 than when lifting.
An exemplary profile of the base term D and of the correction term T is plotted in FIGS. 2 and 3 against the revolution rate n (in stationary operation of the window lifter 1 ) or against the temperature measurement variable T.
It can be seen here from FIG. 2 that the value of the base term D increases approximately linearly with the revolution rate n between limit values n min and n max , between which the revolution rate n typically lies within the steady state mode of the window lifter 1 . Instead of being plotted against the revolution rate n, the base term D can equivalently also be plotted against the battery voltage U B , since the revolution rate n that is set during steady state operation of the window lifter 1 correlates with the battery voltage U B .
It is also shown in FIG. 3 that the correction term K increases continuously in a permissible temperature range between temperature limits T min and T max .
The respective profiles of the base term D and of the correction term K are preferably determined empirically using laboratory tests on at least one test example of the window lifter 1 while varying the ambient temperature and the battery voltage U B . In a developed embodiment of the invention, the base term D and/or the correction term K are defined with an additional dependency on a characteristic dependency on the age of the window lifter 1 . For example, the base term D and the correction term K are increased linearly with the number of load cycles performed by means of the window lifter 1 . In addition or alternatively to said age dependency, the correction term K can also be stored with its own dependency on the revolution rate n. The base term D and the correction term K are preferably stored in the control unit 12 as mathematical functions.
In FIG. 4 the profile of the physical (i.e. actual) actuating position x of the window pane 2 is plotted against time t and is compared with the corresponding profile of the actuating position measurement x′ calculated using the revolution rate of the motor for lifting the window pane 2 . It can be seen from said representation that the actuating motor 3 is switched off by the control unit 12 at a switch-off point in time t A at which the actuating position measurement x′ exceeds the switch-off position x′ A . Following the switching off, owing to its mechanical inertia the actuating motor 3 continues to run on by an actuating displacement interval that is referred to as the overrun x′ N of the actuating motor 3 . The overrun x′ N is the larger here, the greater is the revolution rate n at the switch-off point in time t A .
Owing to its own mechanical inertia as well as the elasticity of the actuating mechanism 4 , as a rule the window pane 2 also runs on following the actuating motor 3 stopping by a small actuating displacement interval that is referred to as the overrun x N of the window pane 2 . The window pane 2 thus actually stops at an end position x E that is given by the switch-off position x′ A plus the overrun x′ N of the actuating motor 3 and the overrun x N of the window pane 2 :
x E =x′ A +x′ N +x N
The base term D of the lead x V is now selected such that it corresponds to the sum of the overrun x′ N of the actuating motor 3 and the overrun x N of the window pane 2 (D=x′ N +x N ). Thus, when lifting the window pane 2 , the overrun x′ N of the actuating motor 3 and the overrun x N of the window pane 2 are just compensated by the lead x V , whereby the end position x E corresponds to the desired target position x Z (x E =x Z ). The lead x V is thus dimensioned such that the window pane 2 stops as accurately as possible at the target position x Z .
FIG. 5 shows the profile of the actuating position measurement x′ and the physical actuating position x when lowering the window pane 2 , wherein here too the actuating motor 3 is switched off at the switch-off point in time t A before the window pane 2 has reached its target position x Z . It can be seen from FIGS. 4 and 5 that the overrun x′ N of the actuating motor 3 is at least substantially independent of the actuation direction, but that the overrun x N of the window pane 2 is significantly greater when lowering ( FIG. 5 ) than when lifting ( FIG. 4 ). Said finding is taken into account by the control unit 12 by the same increasing the lead x V according to FIG. 5 by the correction term K. The correction term K is selected here such that the sum thereof with the base term D corresponds to the sum of the overrun x′ N of the actuating motor 3 and the overrun x N of the window pane 2 (D+K=x′ N +x N ). Thus the overrun x′ N of the actuating motor 3 and the overrun x N of the window pane 2 are also just compensated by the lead x V when lowering the window pane 2 , so that the end position x E again corresponds to the desired target position x z (x E =x Z ) and the window pane 2 stops as accurately as possible at the target position x Z .
Although the invention in the described exemplary embodiment is particularly significant, it is not restricted to said embodiment. Rather, other embodiments of the invention can be derived from the above description by the person skilled in the art.
REFERENCE CHARACTER LIST
1 window lifter
2 (vehicle) window pane
3 actuating motor
4 actuating mechanism
5 actuation distance
6 open position
7 closed position
8 motor shaft
9 drive worm
10 worm wheel
12 control unit
13 angular position sensor
14 temperature sensor
x actuating position
S H pulse signal
x′ actuating position measurement
n revolution rate
T (temperature) measurement value
U M operating voltage
U B battery voltage
x′ A switch-off position
x Z target position
x V lead
D base term
K correction term
n min limit value
n max limit value
T min temperature limit
T max temperature limit
t time
t A switch-off point
x′ N overrun
x N overrun
x E end position | In order to be able to precisely approach a target position of a movable vehicle part by way of a motorized actuator using simple features, an actuating motor of the actuator is stopped by a predetermined advancing lead before the target position is reached. The advancing lead is varied here depending on the rotational speed of the motor or an actuating speed measurement variable correlated therewith and depending on a temperature measurement variable characteristic of the ambient temperature of the actuator. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates to a polychrome lighting device, particularly adapted for use in household and work spaces, in the theatrical, catering, and showbusiness fields, and the like.
Conventional lighting means used to light indoor spaces of buildings and the like are currently predominantly constituted by so-called white-light lamps, which emit a light which is often "cold" and therefore not particularly pleasant both from the visual point of view and from the emotional point of view for people living in such enclosed spaces.
Studies have proved a close correlation between the mood of an individual, his working efficiency, and the type of light that illuminates the space in which he lives.
In other fields, for example in the theatrical field, where it is indispensable to provide particular stage effects, it is commonly known to use a light source in front of which colored filters are placed in order to provide desired color combinations.
A drawback of this solution is the need to move the various filters manually in front of each other, with the problem of the noise linked to this movement and of the complexity of the device which is required.
For example, in the case of theaters, where absolute silence is required, such a solution has considerable drawbacks in application.
The transfer of this solution to other enclosed spaces appears to be even more troublesome due to the difficulty in finding adapted spaces and to cost and complexity issues.
SUMMARY OF THE INVENTION
A principal aim of the present invention is therefore to provide a polychrome lighting device which allows to achieve lighting of the desired color.
Within the scope of this aim, an object of the present invention is to provide a polychrome lighting device which provides a light of the desired color in an automated fashion.
Another object of the present invention is to provide a polychrome lighting device which can be used in any enclosed space.
Another object of the present invention is to provide a polychrome lighting device which does not entail the manual movement of filters.
A further object of the present invention is to provide a device which is highly reliable and relatively easy to manufacture at competitive costs.
This aim, these objects, and others which will become apparent hereinafter are achieved by a polychrome lighting device, characterized in that it comprises at least one light source for each one of the three primary colors and means for adjusting said light sources, said adjustment means being adapted to independently control the adjustment of the luminous intensity and/or light flux of said light sources to combine the light beams emitted by said sources into a light beam having the desired shade.
BRIEF DESCRIPTION OF THE DRAWINGS
Further characteristics and advantages of the invention will become apparent from the following detailed description of a preferred but not exclusive embodiment of the device according to the invention, illustrated only by way of non-limitative example in the accompanying drawings, wherein:
FIG. 1 is a block diagram of the device according to the invention; and
FIG. 2 is an exemplifying block diagram of a remote control according to the invention for controlling the device illustrated in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIG. 1, the device according to the invention comprises three light sources which are appropriately filtered in the three primary colors: red, green, and blue. The three light sources are designated by the reference numerals 1, 2, and 3 respectively. The filters, of a known type, are not referenced in the figure.
There is also provided a fourth white-light source 8.
The four light sources 1, 2, 3, and 8 are appropriately constituted, for example, by filament lamps, each provided with a filter, or by discharge lamps (for example fluorescent lamps) which respectively emit light of (in) said colors.
The colors of the filters used are therefore red, green, blue, and white.
The mixing of the three primary colors (red, green, and blue) allows to obtain any desired color.
Adjustment means 4 are provided to switch on and off and adjust the lamps 1, 2, 3, and 8.
The adjustment means 4 can be of the electromagnetic or electronic type. In the electronic version, they comprise processing means, advantageously constituted by a microprocessor 5, and signal detection means, constituted for example by an infrared sensor 6.
The microprocessor 5 is connected to non-volatile memory means 7, which are adapted to store values of the luminous intensities and/or of the light flux of each one of the light sources 1, 2, 3, and 8.
Each lamp 1, 2, 3, and 8 is controlled independently so as to switch on, switch off, and be adjusted by the microprocessor 5 by means of adjustment circuits with power control 9, which are adapted to adjust the luminous intensity gradually from a zero value to the maximum value.
Advantageously, said adjustment circuits 9 comprise, for example, a triac. There is provided a triac 9 for each lamp.
Power supply means 10 supply said microprocessor 5 and said triacs 9.
Remote control means, shown as a block diagram in FIG. 2, control the device of FIG. 1.
In detail, the remote control means comprise a microprocessor 11 which is connected to nonvolatile memory means 12, to display means 13, to signal transmission means 14, and to data entry means 15.
Advantageously, for example, the display means comprise an alphanumeric liquid-crystal display, the signal transmission means 14 comprise an infrared transmitter, and finally the data entry means comprise for example a keyboard.
Power supply means, advantageously constituted by a battery 16, are connected to power supply control means 17 and to the microprocessor 11.
The power supply control means 17 have the purpose of protecting the charge of the battery by switching on the remote control means at the first pressing of a key of the keyboard 15 and switching them off after a preset idle time.
The three lamps for the three primary colors 1, 2, and 3, plus optionally the fourth lamp 8 for white light, are orientated in a fixed arrangement in the same direction, so that their light beams merge into a single beam.
With reference to the above figures, operation of the device according to the invention is as follows.
The user, through the remote control means, sets for each lamp 1, 2, 3, and 8 (if provided) a luminous intensity or light flux value at will, so that the lamps emit beams of light, filtered by the filters of the three primary colors, which merge into a single beam, the shade whereof is obviously a function of the value of the luminous intensity value assigned to each lamp.
In this manner it is possible to obtain light effects with variable and soft colorings and the user can select a color combination of his liking.
The adjustment means 4 and the triacs 9 allow a gradual adjustment of the luminous intensity of the lamps or of the light flux from a minimum value to a maximum value.
If the luminous intensities of the lamps of the three primary colors 1, 2, and 3 are set to the same value, white light is obtained; otherwise, all the possible color shades of the spectrum are obtained.
The most strongly defined color, given by the combination of the three color beams of the lamps 1, 2, and 3, will occur at the center of the beam produced by the combination/mixing of the three individual beams, whilst softer tints will be provided at the edges of the resulting beam.
The white-light lamp 8 has the purpose of emitting a light of ordinary color when the user does not wish to use the color possibilities offered by the device according to the invention and seeks a light which is different from the light offered by the three lamps 1, 2, and 3, adjusted in a similar manner.
The remote control means allow to adjust from a distance the luminous intensity values of each one of the lamps 1, 2, 3, and 8 and to store the set combination, if one wishes to, in the nonvolatile memory means 12.
As a consequence of the pressing of keys on the keyboard 15 of the remote control means, the microprocessor 11 stores in the memory means 12 the command received from the keyboard 15, actuates the display means 13, actuates the adjustment means 15 by means of the infrared transmitter 14 in order to drive the lamps 1, 2, 3, and 8, and finally controls the power supply control means 17.
The set combination of the luminous intensities, if stored by the user, can therefore be retrieved at a later time.
The nonvolatile memory means 12 can have predefined luminous intensity combinations pre-stored in them which can be retrieved directly from the keyboard and are complemented by those programmed by the user.
A code is assigned to the preset combinations and is displayed on the liquid-crystal display 13 when said combinations are used.
As shown above, the lamp 8 is not indispensable for the operation of the device according to the invention but is an additional possibility offered to the user if he wishes to have a conventional white light.
The three or four lamps or light sources (according to the situation) therefore constitute a single lamp which is capable of emitting a light beam having infinite color combinations.
The device according to the invention also has a switch (not shown) for the emergency control of the lamp if the remote control means break down or if their battery 16 is drained.
In practice it has been observed that the device according to the invention fully achieves the intended aim, since it allows to mix, in a single beam, the light beams of the three primary colors, with the possibility of varying, independently for each beam, the luminous intensity in order to produce light effects having infinite possible shades.
operation of the device is controlled by remote control means which allow to adjust, store, and retrieve desired luminous intensity combinations without having to directly access the device.
Mixing of the three red, green, and blue monochrome beams which originate from three separate sources allows to overcome the drawback of conventional devices, in which it is necessary to manually move filters arranged on a single source, consequently generating noise.
The device thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the inventive concept.
Thus, for example, the lamps 1, 2, 3, and 8 can be orientated independently of each other in order to produce more differentiated light effects.
The three colors of the three incandescent lamps are not necessarily limited to the three primary colors but may also be different colors. In this case, of course, the resulting color combinations will also be different.
Moreover, the remote control means can be radio control means.
Finally, all the details may be replaced with other technically equivalent elements.
In practice, the materials employed, so long as they are compatible with the specific use, as well as the dimensions, may be any according to the requirements and the state of the art. | A polychrome lighting device, including at least one light source for each one of the three primary colors and elements for adjusting the light sources, the adjustment elements being adapted to independently control the adjustment of the luminous intensity of the light sources in order to combine the light beams emitted by the sources into a light beam having the desired shade of color, remote control elements being also provided for setting, storing, and retrieving desired luminous intensity values of the light sources and therefore desired light colors. | 5 |
BACKGROUND OF THE INVENTION
Parasitic worms afflict mammals and fowl and thus pose an economic problem in the raising of cattle, swine, poultry and fur-bearing mammals. A significant number of compounds containing an amidine structural feature have shown significant anthelmintic activity, e.g., levamisole, albendazole, thiabendazole, morantel and bunamidine. However, a compound that is active against one type of worm is not necessarily active against other types. Likewise, toxicity often varies from one host animal to the next. Therefore there is a need for new agents with activities against a broad spectrum of endoparasitic worms and with low toxicity toward the host.
Numerous isoxazoles, isoxazolines and isoxazolidines have been isolated from natural sources or synthesized, and individual compounds or closely-related groups of compounds have been reported to be active as herbicides, or anti-protozoan drugs, or hypoglycemic agents, or anti-inflammatory agents or anti-pyretic agents. It is obvious that having activity against one particular pest or biological dysfunction does not mean a compound will also be active against parasitic worms. In addition, the activity of a compound even against a single pest is almost impossible to predict from its structure. For example, two structurally similar compounds can have dramatically different anthelmintic activities, one being very effective and the other totally ineffective.
SUMMARY OF THE INVENTION
It is an object of the invention to provide new compounds having anthelmintic activity.
It is an additional object of the present invention to provide new compounds having activity with low toxicity against gastrointestinal nematode infestations and cestode infestations in animals.
It is a further object of the invention to provide a process for synthesizing the new compounds.
It is another object of the invention to provide a method of treating mammals or fowl which are infested with parasitic worms or treating mammals or fowl to prevent infestation by parasitic worms.
In accordance with this invention there are provided anthelmintic compounds of the formula: ##STR1## wherein R 1 is hydrogen, or methyl, and Y is aryl, arylalkyl, alkenyl, heteroarylalkyl, heteroarylheterocyclic, arylheterocyclic, or arylcycloalkyl group. Aryl groups, which include phenyl and naphthyl groups, may be substituted with nitro, alkyl, alkoxy or halo groups. Alkenyl groups generally contain from 2 to 20 carbon atoms, and may contain from 1 to 3 unsaturated bonds between adjacent carbon atoms. Heteroaromatic groups may be, for example, pyridyl, which may be substituted with a nitro group. Heterocyclic groups may include pyrrolidinyl, piperidinyl and piperazinyl groups. Cycloalkyl groups generally have 3 to 7 carbon atoms.
In another embodiment, this invention provides a method of treating animals with the claimed compounds. The invention also contemplates a method of making the claimed compounds.
The compounds of the present invention provide effective control of endoparasites. Moreover, they are relatively non-toxic to the host animals, thereby providing an obvious benefit in the husbandry of these animals.
DETAILED DESCRIPTION OF THE INVENTION
The isoxazoles of this invention have the formula ##STR2## wherein R 1 is hydrogen, or methyl, and Y is aryl, arylalkyl, alkenyl, heteroarylalkyl, heteroarylheterocyclic, arylheterocyclic, or arylcycloalkyl group. Aryl groups, which include phenyl and naphthyl groups, may be substituted with nitro, alkyl, alkoxy or halo groups. Alkenyl groups generally contain from 2 to 20 carbon atoms, and may contain from 1 to 3 unsaturated bonds between adjacent carbon atoms. Heteroaryl groups may be, for example, pyridyl which may be substituted with a nitro group. Heterocyclic groups may include pyrrolidinyl, piperidinyl and piperazinyl groups, which may be substituted with a nitro group. Cycloalkyl groups generally have 3 to 7 carbon atoms.
Particularly preferred compounds of the present invention are N-(3-chloro-4,5-dihydroisoxazol-4-yl)-N'-phenylpropylphthalamide, N-(3-chloro-4,5-dihydroisoxazol-4-yl)-N'-4-bromobenzylphthalamide, and N-(3-chloro-4,5-dihydroisoxazol-4-yl)-N'-tolylethylphthalamide.
The compounds of this invention are active in controlling parasitic worms such as the hookworm N. dubius, the roundworm N. brasiliensus, the tapeworm H. nana, and the pinworms S. obvelata and A. tetraptera. Each of the compounds is effective against one or more of the worms but, as the examples demonstrate, each may not be effective against all species. Simple activity tests, within the skill of the art, can be employed to identify the spectrum of activity of any given compound.
Preparation of the compounds of this invention from D-cycloserine desirably is achieved by first protecting the active amino group by reacting D-cycloserine with a phthaloyl-containing compound to form a phthalimide with the 4-amino group of the D-cycloserine. One appropriate means is the use of N-carboethoxyphthalimide as the phthaloyl-containing compound as reported by Nefkens (Nature, 185, 309, 1960). This reaction can be carried out in the presence of sodium carbonate in aqueous solution at room temperature. Alternative methods of protecting the active amino group include using o-methoxycarbonylbenzoyl chloride as the phthaloyl-containing compound instead of N-carboethoxyphthalimide, as described by Hoogwater (Recueil de Travaux Chimiques de Peys-Bas, 92, 819-825, 1973), and via silylation followed by reaction with a phthaloyl chloride as described by Kume (Tetrahedron Letters, 23, 4365, 1981).
After the amino group has been protected, the ring system is modified by reaction with a phosphorous chloride. For example, the corresponding imidoyl chloride, 3-chloro-4-phthalimido-4,5-dihydroisoxazole can be formed by reaction with phosphorous oxychloride, as disclosed in J. Amer. Chem. Soc. 103, 942 (1981). Alternative methods of forming the imidoyl chloride include reaction with phosphorous pentachloride in refluxing nitromethane. This however is harsher than the method here employed, and tends to result in a lower yield of desired product and the formation of the undesired by-product 3-(3-keto-4-phthalimido-isoxazoline-2-yl)-4-phthalimido-isoxazoline.
The imidoyl chloride, 3-chloro-4-phthalimido-4,5-dihydroisoxazole, is a useful intermediate which can be used to make the compounds of this invention, as well as other compounds.
To form the compounds of the present invention, suitable amines such as, N-arylamines, N-arylalkylamines, N-alkenylamines, N-heteroarylalkylamines, N-heteroarylheterocycloamines, N-arylheterocycloamines, or N-arylcycloalkylamines are reacted in a suitable solvent, such as tetrahydrofuran with the intermediate imidoyl chloride, discussed above. Such reactions proceed readily at room temperature. Preferably, the amine is selected from the group consisting of benzylamine, p-methylbenzylamine, m-methylbenzylamine, p-methoxybenzylamine, alpha-methylbenzylamine, phenethylamine, p-tolylethylamine, N-methylphenylethylamine, beta-methylphenethylamine, beta-3,4-dimethoxy-phenylethylamine, phenylpropylamine, phenylbutylamine, fluorobenzylamine, 4-chlorobenzylamine, 4-bromobenzylamine, 2- and 3-pyridylmethylamines, 2- and 3-pyridylethylamines, piperonylamine, 4-(2-pyridyl)piperazinylamine, 4-phenylpiperazinylamine, 4-phenylpiperidinylamine, oleylamine, allylamine, 1-naphthalenemethylamine, phenylcyclopropylamine, and 3-fluorobenzylamine. Nucleophilic addition results in the formation of N-(3-chloro-4,5-dihydroisoxazol-4-yl)-N'-(substituted)-phthalamides.
The products can be isolated from the reaction medium by first concentrating the reaction mixture (e.g., in an evaporator) and then recrystallizing the compounds from a suitable solvent, such as ethyl acetate, or purifying by flash chromatography on silica gel and eluting with an appropriate solvent system, such as petroleum ether-ethyl acetate. Other methods of isolation will be apparent to those skilled in the art.
Parasitic worms afflict both mammals and birds, therefore the present invention is useful in the raising and husbandry of livestock such as cattle, swine, sheep and goats, domestic pets such as dogs and cats, rabbit, poultry such as turkeys, ducks, chickens and geese, and fur-bearing animals such as foxes, chinchilla and mink. The compounds of the present invention can be administered orally by conventional means and techniques known in the art. They can be used prophylactically to protect animals from infestation or therapeutically after the animals have been infested. In general, prophylactic dosages will be lower than those for pre-existing infestations. For example, dosages as low as 1 mg/kg of body weight may be sufficient to protect an animal from infestation by parasitic worms. Therapeutic dosages will often be from 10 to 100 times greater than prophylactic dosages.
The dosage used will depend on: (1) the animal to be treated; (2) which compound is to be used; (3) the infesting worms; and (4) the time and method of administration. Determination of the proper dosage in light of these variables is within the control and competence of one skilled in the art.
The chemotherapeutic agents of this invention can be administered in any of a variety of forms, alone or in combination, with other pharmaceuticals. They can be administered in a solid form or in liquid form in a suitable solvent. For example, they may be administered orally in admixture with an animal feed or fed separately as a supplement. Appropriate amounts of anthelmintic compound in the animal feed for therapeutic treatment of pre-existing infestations often are from about 300 ppm to about 2000 ppm.
Suitable dosages often are from about 0.5 to about 200 mg of active ingredient per kg of body weight of the host animal, depending on the particular compound, the infesting pest, the degree of infestation and the program of administering.
EXAMPLE 1
Phthaloylation of D-cycloserine with N-carboethoxyphthalimide
D-cycloserine (15.3 g, 0.15 mol) and sodium carbonate (15.9 g, 0.15 mol) were dissolved in 200 ml of water. N-carboethoxyphthalimide (36.0 g, 0.164 mol) was added to the solution and the mixture was stirred for 25 minutes and then filtered to remove unreacted N-carboethoxyphthalimide (12.1 g). The filtrate was chilled on ice bath and acidified with 4N HCl. Phthaloyl-D-cycloserine (18.5 g) precipitated out of solution and was collected by filtration, air dried, and recrystallized from ethyl acetate.
EXAMPLE 2
The synthesis of 3-chloro-4-phthalimido-4,5-dihydroisoxazole
The compound prepared in Example 1, phthaloyl-D-cycloserine (9.28 g, 40 mmol), was dissolved in 100 ml of nitromethane. Phosphorous oxychloride (4 ml, 43 mmol) was added to the solution, which was then heated to 100° C. in a two-hour period and kept at that temperature for an additional hour. The mixture was cooled to room temperature, and the solids were filtered off. The filtrate was concentrated, and the residue was extracted with ehtyl acetate. The solvent was removed and the product was purified by flash chromatography and eluted with 3:1 petroleum ether/ethyl acetate to yield 3-chloro-4-phthalimido-4,5-dihydroisoxazole (5.49 g).
EXAMPLE 3
The preparation of N-(3-chloro-4,5-dihydroisoxazol-4-yl)-N'-(benzyl)phthalamide
3-Chloro-4,5-phthalimido-4,5-dihydroisoxazole (2.5 g, 10 mmol) was dissolved in 100 ml of dried tetrahydrofuran. To the solution, 10 ml of benzylamine was added at room temperature. The reaction was stirred at room temperature for 4 hours, then concentrated in vacuo to remove solvent and excess benzylamine. Ethyl ether was added to the residue and insoluble solid was filtered off. The product was recrystallized from ethyl acetate to give 2.49 (69.6%) of the desired product.
EXAMPLE 4
The preparation of N-(3-chloro-4,5-dihydroisoxazol-4-yl)-N'-(p-methylbenzyl)phthalamide
3-Chloro-4-phthalimido-4,5-dihydroisoxazole (4 g, 16 mmol) was dissolved in 50 ml of dried tetrahydrofuran. 4-Methylbenzylamine (2.18 g, 18 mmol) was added at room temperature and the reaction solution was stirred at room temperature for 4 hours. The reaction mixture was concentrated in vacuo, and the residue recrystallized from chloroform to give 4.8 (80.7%) of the desired product.
EXAMPLE 5
The preparation of N-(3-chloro-4,5-dihydroisoxazol-4-yl)-N'-(m-methylbenzyl)phthalamide
This reaction was performed as in example 2, except that the phenylalkylamine added was m-methylbenzylamine (1.94 g, 60 mmol) and the reaction was carried out for six hours. The reaction product was recrystallized from ethyl acetate giving 4.79, (80.5%) of the desired product.
EXAMPLES 6-17
Compounds 6-17 were synthesized from the compound of Example 2 in a manner analogous to the methods of examples 3, 4 and 5. Different conditions and reagents are as noted below.
__________________________________________________________________________ml ofTetra- mmolehydro- phenyl- Reaction Recrystal- grams ofExamplefuran alkyamine Amine Time lized from product__________________________________________________________________________ 6 25 16 p-methoxybenzylamine 4 hr ethyl acetate 0.93 7 75 32 alpha-methylbenzylamine 4 days ethyl acetate 1.45 8 50 32 phenethylamine 4 hr ethyl acetate 4.4 9 50 28 p-tolylethylamine 4 hr ethyl acetate 4.2810 50 17 beta-methylphen- 18 hr chloroform- 4.4 ethylamine hexane11 50 17 beta-(3,4-dimethoxy- 4 hr ethyl acetate 5.9 phenyl) ethylamine12 50 17 3-phenyl-l-propylamine 4 hr ethyl acetate 4.9413 50 17 4-phenylbutylamine 4 hr ethyl acetate 4.2614 50 17 p-fluorobenzylamine 4 hr ethyl acetate 5.3215 50 17 p-chlorobenzylamine over- ethyl acetate 5.17 night flash chromotographed and eluted with16 50 17 N-- methylphenethylamine 3 days 2:1, 1:1 pet- 0.92 roleum ether/ ethylacetate, ethyl acetate17 50 17 4-bromobenzylamine-HC1 4 hr ethyl acetate 4.99 50 triethylamine__________________________________________________________________________
EXAMPLE 18
The compounds described above were administered to worm-infested mice in their diet, and the reductions in worm number were recorded. The results for the four worms against which the compounds were tested and showed good activity are tabulated in Table 2. The anthelmintic activity is based on reduction in worm burden and expressed as percent effectiveness.
No toxicity was observed in mice when these compounds were injected intraperitoneally (i.p.) at levels of 100 mg/kg of body weight or when fed at levels of 1,000 ppm in the diet.
TABLE 2__________________________________________________________________________Anthelmintic Activity ofN-- (3-chloro-4,5-dihydroisoxazol-4-yl) - N'--(substituted)phthalmidesCompound of DosageExample ppm in % Reduction in the Number of WormsNo. diet N. brasiliensis H. nana S. obvelata A. tetraptera__________________________________________________________________________3 2000 100 100 100 1000 100 98 100 500 0 100 300 46.54 1000 100 100 100 500 100 99 100 300 63.85 1000 43 100 100 500 32 0 98 300 55.76 1000 64 68 63 500 100 0 100 300 48.07 1000 74 43 66 500 0 31 82 300 45.78 1000 100 98 100 500 100 29 100 300 44.29 1000 100 67 100 500 100 0 100 300 50.610 1000 100 0 100 500 100 0 100 300 2511 1000 100 0 100 500 100 0 100 300 30.612 1000 100 100 100 500 100 91 100 300 6813 1000 100 100 100 500 100 0 90 300 39.214 100 100 0 100 500 0 0 100 300 2515 1000 100 100 100 500 0 0 96 300 2516 1000 100 100 100 500 100 47 47 300 44.517 1000 100 100 100 500 0 0 96 300 46.9__________________________________________________________________________ At 2,000 ppm N-- (3chloro-4,5-dihydroisoxazol-4-yl)-N'--(benzyl)phthalamide shows activity against the hookworm N. dubius, in being able to reduce the size of the worm.
EXAMPLES 19-31
The following compounds were synthesized in analogous reactions to those discussed above in Examples 3-18 using the corresponding amine as a reagent. Each was tested against the worms H. nana and N. dubius at a dosage of 1,000 ppm using the procedure described in Example 18.
Although none of these compounds proved effective in reducing the number of N. dubius, the compound of Example No. 30 had the effect of stunting N. dubius.
______________________________________ % N--(3-chloro-4,5-dihydro- ReductionCompound of isoxazol-4-yl)-N'--(substituted) in No. ofExample No. phthalamide H. nana______________________________________19 3-pyridylmethyl 10020 4-pyridylethyl 10021 2-pyridylethyl 10022 2-pyridylmethyl 10023 4-nitro-2-pyridylamino-ethyl 10024 piperonyl 10025 4-phenylpiperazinyl 10026 4-phenylpiperidinyl 10027 oleyl 7228 allyl 10029 1-naphthalenemethyl 10030 trans-phenylcyclopropyl 10031 m-fluorobenzyl 77______________________________________ | Novel phthalamide compounds are disclosed having activity against a broad spectrum of parasitic worms and showing no toxicity to the host animal. These compounds are N-(3-chloro-4,5-dihydroisoxazol-4-yl)-N'-(substituted)phthalamides. A process for making these compounds and a method of administering them to animals are also disclosed. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a lamp assembly, and more particularly, to an improved lamp assembly typically installed on aircraft evacuation slides, wherein the assembly is designed to withstand the static and dynamic forces realized when the slide is folded into a compact, volumetrically efficient package for storage and then expanded rapidly.
2. Description of the Prior Art
Inflatable evacuation slides, or rafts, are installed on substantially all passenger aircraft to allow for rapid evacuation in the event of an emergency. In the deflated state, the evacuation slide is tightly folded into a compact compartment near or within the aircraft doorway. A girth bar is extended from the inflatable evacuation slide and connected to brackets on the floor inside the aircraft doorway, such that the slide is simultaneously deployed with the opening of the door. When the door is opened, the slide is pulled from its container by the girth bar and deposited through the open doorway. The slide is then automatically inflated, making it ready for the evacuation of passengers.
Since a substantial amount of flying is done at night, it is imperative for the safety of the passengers that the slides are well lit. Therefore, illumination is provided by lamp assemblies which are mounted to the evacuation slides. The problem is that when the slides are compacted into their storage areas, tremendous forces are exerted on the housing assemblies. Similar forces are applied to the housing assemblies when the slides are deployed and expanded rapidly. Unfortunately, conventional lamp assemblies are commonly damaged and rendered inoperable under these forces, especially during emergency situations.
Conventional lamp housing designs make them highly susceptible to such damage and inefficient for maintenance purposes. For instance, the housing assemblies are fabricated from materials incapable of withstanding the higher forces realized by today's compact packing techniques. In addition, the lamp housing structures incorporate flat conductor cables that are installed with inadequate strain relief. The result is a rigid interface between the flat conductor cable and the lamp housing edges which cause the conductors and housings to crimp, break and fail under the static and dynamic forces. Moreover, time consuming procedures are required to replace and repair lamps and their housings in that the housings must be pried apart and lamps replaced by potentially injurious, hazardous, and complex soldering techniques. Thus, a more stress resistant lamp housing structure is needed, and particularly one that can be more conveniently maintained.
Improvements in the ability to create smaller, denser evacuation packages have caused structural failures in the prior art lamp enclosures and ultimately cause lamp breakage. Furthermore, the prior art lamp housing conductor is a flat conductor cable. The interface of the flat conductor cable and the prior art lamp housing has caused conductor failures since the prior art lamp housings do not effectively strain relieve the flat conductor, particularly when the prior art design is used in new, smaller, denser evacuation packages. Consequently, there remains a need for a more curvilinear and pliable lamp housing structure. The present invention solves these problems by providing in the preferred embodiment a housing that is able to secure the lamp without soldering, and by providing a lamp housing conductor that is a round conductor cable, while absorbing the static and dynamic forces encountered today without failing.
SUMMARY OF THE INVENTION
The present invention provides an improved lamp housing assembly that has increased durability and convenience for mounting to aircraft evacuation slides or the like. The lamp housing comprises a cover or top housing, and a base or bottom housing which adaptably mate and couple to each other in interlocking engagement, such that the cover is superposed over the base. In the preferred embodiment, The base defines a lamp receiving aperture which secures the lamp in twist lock engagement so that the lamp may be easily installed and replaced. Meanwhile, the cover defines a lamp compartment with cylindrically recessed levels that align and mate with the base and lamp combination. The base and cover are injection molded and made of a plastic resin for ease of manufacture and for adequate light dispersement from the lamp.
The cover has at least two sides and opposite end segments, wherein at least one end segment defines an arcuate depression. The base has at least two sides and opposite end segments, wherein at least one of the base end segments defines a complimentary arcuate protrusion, such that the cover's arcuate depression receives the base's arcuate protrusion. The cover also includes rounded outer surfaces which blend with the arcuate depressions to form the classical "S" shaped strain relief feature and maintain the minimum bend radii for the conductor and insulation used in the wire when the top and bottom housings are snapped together. Thus, the conductive wire bends around the arcuate protrusion and rounded outer surface when the base and cover are coupled to effectuate the strain relief that prevents the wire from becoming fatally deformed.
The complete housing is formed by the interlocking of the cover and base. The cover includes a flange or lip longitudinally disposed along the inner surface of its two sides, the flanges being resilient and biasing. The base includes complimentary grooves along the outer surface of its two sides for receiving the flange of the cover, thereby providing a snap fit or snap lock feature. The flanges deflect slightly then recover as the cover fits into the grooves of the base. The housing's snap fit feature is designed to accommodate without failure the static and dynamic forces encountered by the housing both when the evacuation slides are folded into tight, volumetrically efficient packages and when the slides are rapidly expanded. In addition, the outer surfaces of both the cover and base have rounded edges to avoid puncturing the slide.
Assisting the snap fit feature in its function are alignment openings in the base and corresponding guide pins in the cover. These openings accept the guide pins which protrude from the interior of the cover and align the cover and base for assembly. Longitudinal movement of the cover and base relative to each other is also minimized by the alignment feature.
As noted above, in the preferred embodiment, the lamp is secured within a receiving aperture defined by the base and is supplied power through a conductive wire harness. In the preferred embodiment, the conductive wire harness is in the form of round wire. The conductive wire harness interposes the cover and the base as it passes through the housing assembly and is secured therein by a wire guide in the cover which captures the round wire and holds it in its intended position within the lamp housing assembly. At least two insulation displacement terminals, or splicing terminals, are fixedly and/or integrally secured to the interior of the base such that they protrude in an upward direction. The splicing terminals electrically communicate with the lamp through circuit paths at one end and include a cutting edge at the other end for splicing through the wire harness insulation to allow direct contact with the wire. Consequently, the conductive wire harness and the lamp are in electrical contact with one another, thereby providing continuity without the need for soldering the lamp leads to the wire harness. The conductive wire harness is connected to a power source on the evacuation slide or on the aircraft. In the preferred embodiment, the lamp is removable for easy maintenance.
In an alternative embodiment, the lamp may be non-removable without departing from the scope of the instant invention. The important aspect of providing a curvilinear and pliable lamp housing that is able to accommodate the static and dynamic forces encountered by the housing and which is conducive to modern aircraft needs is still obtained. In this embodiment, as in the preferred embodiment, no soldering is necessary, and the snap fit feature allows for the easy removal and replacement of the lamp. Furthermore, the S-shaped strain relief feature is incorporated. In an additional embodiment, the housing is designed to accommodate a flat cable conductor. In this embodiment, the lamp leads must be soldered to the flat conductive cable to provide continuity. However, the aforementioned S-shaped strain relief feature is still incorporated, thereby eliminating all sharp edges and incorporating curvilinear lines. Furthermore, in this embodiment, the guide pins penetrate the conductor when the cover and base are interlocked, thereby locking the conductor in place. Additionally, the snap fit feature allows for the easy removal and replacement of the lamp.
An improved lamp housing assembly is provided with the present invention which vastly reduces the instances of a lamp housing structure failure due to the forces applied to the lamp housing assembly when the evacuation slide is folded into a tight, volumetrically efficient package. The lamp housing assembly is designed to resolve all the technical challenges that have evolved in providing an inexpensive convenient and durable lighting fixture for aircraft evacuation slides.
Accordingly, it is a primary object of the present invention to provide a lamp housing assembly which can withstand the static and dynamic forces applied to all surfaces of the lamp housing assembly when an evacuation slide is folded into tight, volumetrically efficient packages that are then installed in aircraft doorways.
It is an additional object of the present invention to provide a lamp housing assembly with effective strain relief features such that the interface between the conductor cable and the lamp housing does not cause conductor failure.
It is a further object of the present invention to provide a lamp housing assembly which is designed to mount on an inflatable evacuation slide such that it does not cause or contribute to a puncture of the inflated membranes.
It is yet another object of the present invention to provide a lamp housing assembly wherein the lamp is easily replaceable.
It is yet still another object of the present invention to provide a lamp housing assembly with a snap fit feature, allowing for ease of alignment and locking engagement between the cover and the base of the housing.
In accordance with these and other objects which will become apparent hereinafter, the instant invention will now be described with particular reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the preferred embodiment of a lamp housing assembly with a round wire conductor and with a removable lamp;
FIG. 2 is an exploded view of the preferred embodiment of the lamp housing assembly;
FIG. 3 is a perspective view of the interior of the cover or top housing of the preferred embodiment of the instant invention;
FIG. 4 is a perspective view of the interior of the base or bottom housing of the preferred embodiment of the lamp housing assembly;
FIG. 5 is a perspective view of the exterior surface of the base for the preferred embodiment;
FIG. 6 is a top plan view of the preferred embodiment of the lamp housing assembly;
FIG. 7 is a side view of the preferred embodiment of the lamp housing assembly;
FIG. 8 is a cross sectional view of the preferred embodiment of the lamp housing assembly taken along line 8--8 of FIG. 6;
FIG. 9 is a cross sectional view of the preferred embodiment of the lamp housing assembly taken along line 9--9 of FIG. 6;
FIG. 10 is a partial cut away view of the preferred embodiment of the lamp housing assembly taken along line 10--10 of FIG. 6;
FIG. 10A is a detailed view of FIG. 10;
FIG. 11 is a perspective view of an alternative embodiment of the instant invention with a round wire conductor and with a non-removable lamp assembly;
FIG. 12 is an exploded view of the second embodiment of the instant invention;
FIG. 13 is a perspective view of an interior portion of the base of the second embodiment;
FIG. 14 is a top plan view of the second embodiment of the instant invention;
FIG. 15 is a cross sectional view of the second embodiment taken along line 15-15 of FIG. 14;
FIG. 16 is a cross sectional view of the second embodiment of the lamp housing assembly taken along line 16-16 of FIG. 14;
FIG. 17 is a perspective view of a third embodiment of the instant invention illustrating the use of flat conductor cable;
FIG. 18 is an exploded view of the third embodiment of the instant invention;
FIG. 19 is a perspective view of the cover of the third embodiment of the instant invention;
FIG. 20 is a perspective view of the interior portion of the base for the third embodiment;
FIG. 21 is a side view of the third embodiment of the lamp housing assembly;
FIG. 22 is a top plan view of the third embodiment;
FIG. 23 is a cross sectional view of the third embodiment of the instant invention taken along line 23--23 of FIG. 22;
FIG. 24 is a cross sectional view of the alternative embodiment of the lamp housing assembly taken along line 24--24 of FIG. 22.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to the drawings, FIGS. 1-24 depict a lamp housing assembly generally indicated by the reference numeral 10. Throughout the figures, like referenced characters are used to indicate like elements.
Referring now to FIG. 1, the lamp housing assembly 10 of the present invention is shown. The lamp housing assembly generally comprises a bottom housing 20, a top housing 100, a lamp assembly 34, and conductor wire 68. In the preferred embodiment, the bottom housing 20, or base, and the top housing 100 or cover, are coupled in interlocking engagement and the lamp assembly 34 is removable and is also interlocked into the base 20 for easy replacement. As shown in FIGS. 2, 4, and 5, the base 20 includes sides 22 and opposite end segments, wherein at least one end segment defines an arcuate protrusion 24. The base 20 may be injection molded with an engineered plastic resin that is capable of being plated with copper using photo lithographic techniques. The plating of copper on the plastic allows electrical circuit paths 66 to be laid out along an inner surface of the base. The copper also forms the base metal for further plating using a tin/lead alloy or gold on tin/lead alloy plating to improve solderability and corrosion resistance, respectively. The circuit paths 66 electrically interface the negative and positive 36a leads on the lamp assembly 34 with negative and positive leads of the conductor wire 68, respectively, transmitting power from an external source. In the preferred embodiment, the negative and positive leads 36a are in the form of plated copper which is electrically connected to a lamp turret via the circuit.
As seen in FIGS. 1 and 2, an annular aperture 50 is defined by the base 20, thereby allowing the lamp assembly 34 to be installed in an upright position in the base 20. The upright position of the lamp assembly 34 optimizes the light distribution of the lamp 36. The annular lamp aperture 50 is designed to accept the lamp assembly 34 and allow the lamp assembly 34 to be locked into the base 20. As best seen in FIG. 2, the lamp assembly 34 generally comprises a lamp 36, a lamp engagement member 38, and a lamp base 44. Lamp engagement member 38 contains a formed interlocking groove 40 wherein the interlocking groove 40 has a leading edge 40a and a trailing edge 40b, the trailing edge 40b containing a stop 42 for limiting rotation of the lamp assembly 34 and thereby locking the lamp assembly 34 to the base 20, which will be described in greater detail hereinafter.
Referring now to FIG. 5, a lamp assembly access panel 48 may be molded into the bottom side of the base 20 to allow lamp assembly 34 to be removed when it is rotated to an unlocked position using a flat blade screwdriver which fits the slotted recess 46 in lamp base 44. For lamp assembly removal, a screwdriver blade is inserted parallel to access panel 48 and a screwdriver blade is then used to gently lever the lamp assembly out of the base 20 once the lamp assembly 34 has been unlocked. The words "locked," "unlocked," and a rotational arrow symbol may be molded into the bottom surface of the base 20. When the slotted recess 46 is aligned with the words "locked," or "unlocked," the identified position has been achieved.
Referring now to FIGS. 4, 10 and 10a, base 20 further includes insulation displacement terminals, or splicing terminals, 58. The insulation displacement terminals 58 are used to remove the insulation from a stranded, round wire of a specific gauge. The terminals 58 can be sized for a wide range of wire gauges. Splicing terminals 58 include wire lead-ins 60, displacement edges 62, and wire slot 64. As the conductor 68 engages the splicing terminal 58, wire lead-in 60 guides conductor 68 through displacement edge 62, where conductor 68 is spliced, and inserted into wire slot 64. Terminals 58 are conductively plated and engage the conductor wire 68, thereby creating an electrical circuit. Wire conductors 68 are connected to a primary, electro chemical, multiple cell, power unit and are used to carry the current to the lamp assembly 34 installed in the housing. The position of the insulation displacement terminals 58 is driven by the physical dimensions of the wire conductors 68, the lamp 36 and the cold temperature operating environment that dictates the minimum bend radius for the wire insulation to maintain its dielectric properties and for the copper conductor to maintain its mechanical properties.
With reference to FIGS. 2, 4, 5, 8 and 9, the base 20 further includes a lamp turret 52 having a lamp attaching aperture 54 disposed therein and the lamp attaching aperture 54 having recessed areas or notches 56. As previously mentioned, annular aperture 50 is molded into the base 20, allowing the lamp assembly 34 to be installed upright therein. The annular aperture 50 is designed to accept lamp assembly 34 and allow the lamp assembly 34 to be locked into the base 20. Recessed areas 56 form a lip 57, such that lamp engagement member 38 is engaged with recessed area 56 when the lamp assembly 34 is inserted and rotated with a flat blade screwdriver in slotted recess 46. To lock lamp assembly 34 into place, lamp assembly 34 is inserted by hand through annular aperture 50 and locked into the base 20 using a flat blade screwdriver that fits the slotted recess 46 in the lamp base 44. By rotating lamp assembly 34 with a screwdriver, interlocking groove 40 engages the lip 57 until stop 42 is reached, thereby locking lamp assembly 34 to the base 20.
The lamp turret 52 height establishes the lamp filament location within the housing. The lamp filament location is an important optical characteristic of the lamp 36 and lamp housing. The turret height 52 can be increased to change the hemispherical distribution of the light and with changes in the top housing or cover 100 the optical characteristics of the lamp housing assembly can be modified to suit other applications.
As seen in FIGS. 2, 3, 4 and 5, snap fit features are molded in the sides of the base 20 and cover 100. These snap fit features include grooves 70 as defined by the exterior of sides 22 in the base and flanges 124 as defined by sides 102 in the cover. Flanges 124 run longitudinally along the interior of sides 102 and are resilient so that they recover when slightly compressed after being received by grooves 70. The slight deflection in the flange 124 allows the side 102 to give and retract providing alignment and locking engagement of the cover 100 and base 20. As noted above, the lamp housing assembly 10 is installed on evacuation slides that are folded into tight volumetrically efficient packages that are installed in aircraft doorways. When the aircraft door is opened in an emergency the evacuation slide inflates rapidly. In the evacuation slides' packed state, static and dynamic forces are applied to the materials of the slide, including the lamp housing assembly 10. These forces are relatively high and can increase during aircraft operations and crashes. The lamp housing cover and base snap fit features have secure interlocking characteristics which can withstand the static and dynamic forces without the lamp housing structure failing.
As seen in FIGS. 3 and 4, assisting the snap fit features in their function are alignment recesses 72 in the base 20. These recesses 72 accept guide pins 126 of the cover 100 to align the cover 100 and base 20 and constrain the longitudinal movement of the cover 100 and the base 20 relative to each other. In addition, alignment of splicing terminals 58 with displacement terminal recesses 128 in the cover is also achieved.
As seen in FIG. 4, the profile radius 26 of protrusion 24 and the wire transition radius 30 of the base 20 are complimentary to provide strain relief and maintain the minimum bend radii for the wire conductor 68 when the cover 100 and base 20 are snapped together. The point is to provide smooth transitions for the wire 68. The surface of the profile radius 26 may be textured to provide some additional wire strain relief. As seen in FIG. 5, the external edge radii 32 and the opposite end radii 31 are also rounded off, in order to prevent puncturing the slide.
In FIGS. 1, 3, and 7, the cover 100 is shown, generally comprising sides 102 and opposite end segments or lobes 104, wherein at least one end segment 104 defines an arcuate depression 106 on its interior surface for adaptably receiving or mating with its complimentary counterpart the base arcuate protrusion 24. As can be seen in FIGS. 2 and 7, the cover 100 is rounded along its end radii 111, at its external edge radii 112 and its top surface 114, again to prevent puncturing. Wire guide 130 is a groove disposed in the interior of cover 100 along opposite sides 102. Wire guide 130 also runs along the arcuate depression 106 and captures the round wire conductor 68 to hold it in its intended position within the lamp housing assembly 10. The surface area of wire guide 130 may be textured to increase the contact area clamping the wire insulation. This texturing improves the strain relief performance of the exit radii 110 and 26 of the cover and base respectively, when teflon insulation is used on the round wire 68. When flat conductor is used, the exit radius 110 of the cover may be textured to provide additional strain relief, and the wire guide 130 is eliminated.
As seen in FIG. 3, the interior of cover 100 forms a lamp compartment 116 shaped to accept the lamp 36 and to retain any glass fragments if the lamp 36 is broken. The lamp compartment 116 comprises a first cylindrically recessed level 118 for receiving the lamp turret 52, a second recessed level 120 for receiving the lamp engagement member 38, and a third recessed level 122 for receiving the lamp 36.
As seen in FIG. 3, the profile radius 108 of the cover 100 maintains the classical "S" shape strain relief feature. The exit radius 110 of the cover 100 and the profile radius 26 of the base 20 define the wire or flat conductor path within the lamp housing assembly 10. The end radius 111 of the cover 100 provides an acceptable bend radius for the conductor used for all operational environmental extremes. The external edge radius 112 of the cover 100 protects the inflatable evacuation slide from punctures by being somewhat tapered and creates a smooth surface transition that eliminates stress risers in the plastic materials that would decrease the overall strength of the lamp housing assembly. The external edge radius 32 of the base 20 performs the same function. The top surface 114 of the cover 100 may be left smooth or textured to disperse the light emanating from the lamp. The top surface 114 may also be shaped into convex, concave, or combinations of convex and concave surfaces for specific light focusing effects. As aforementioned, the lamp turret 52 of the base 20 can be lengthened to change the position of the lamp filament. The modification of lamp turret 52 would cause the top surface 114 of cover 100 to also change. These changes can be made without effecting the original wire, insulation displacement terminals or base design. It should be noted that this only holds true for the round wire conductor embodiment.
Referring now to FIGS. 11-16, a second embodiment of the instant invention is shown with a round wire conductor and with a non-removable lamp assembly. As described earlier, the lamp housing assembly generally comprises a bottom housing 20, a top housing 100, a lamp assembly 34, and conductor wire 68. The bottom housing 20 and the top housing 100 are coupled in interlocking engagement. Snap fit features are molded in the sides of the bottom housing or base 20 and the top housing or cover 100. These snap fit features include grooves 70 as defined by the exterior of sides 22 in the base and flanges 124 as defined by sides 102 in the cover. Assisting the snap fit features in their function are alignment recesses 72 in the base 20. These recesses 72 accept guide pins 126 of the cover 100, to align the cover 100 and base 20 and constrain the longitudinal movement of the cover 100 and the base 20 relative to each other. In addition, alignment of splicing terminals 58 with displacement terminal recesses 128 in the cover is also achieved. The conductive wire harness 68 interposes the cover 100 and the base 20 as it passes through the housing assembly and is secured therein by a wire guide channel 130 in the cover 100 which captures the round wire 68 and holds it in its intended position within the lamp housing assembly. As previously mentioned, the insulation displacement terminals 58 are used to remove the insulation from a stranded, round wire of a specific gauge, wherein conductor 68 is inserted into wire slot 64. However, it should be noted that in this embodiment, the lamp assembly 34 has wire lamp leads 36a rather than the copper plated lamp leads of the preferred embodiment. Therefore, it is not necessary to plate the base 20 with copper to form electrical circuit paths as in the preferred embodiment. However, the base 20 may be so plated if desired. Insulation displacement terminals 58 are conductively plated and engage the conductor wire 68, thereby creating an electrical circuit. Furthermore, wire lamp leads 36a are inserted into wire slot 64 along with conductor wire 68, thereby creating an electrical circuit.
As discussed above in the preferred embodiment, the cover of the second embodiment has at least two sides 102 and opposite end segments 104, wherein at least one end segment defines an arcuate depression 106. The base similarly has at least two sides 22 and opposite end segments, wherein at least one of the base end segments define a complimentary arcuate protrusion 24, such that the cover's arcuate depression 106 receives the base's arcuate protrusion 24. The cover also includes rounded outer surfaces which blend with the arcuate depressions to form the classical S-shaped strain relief feature, and maintain the minimum bend radii for the conductor and insulation used in the wire when the top and bottom housing are snapped together. In this second embodiment, as in the preferred embodiment, no soldering of wire lamp leads directly to the conductor wire is necessary, and the snap fit feature allows for the easy removal and replacement of the lamp should a lamp failure occur. In addition, as discussed for the preferred embodiment above, the outer surfaces of both the cover and base have rounded edges to avoid puncturing the slide.
Essentially, the only difference between the preferred embodiment and the second embodiment is that the lamp assembly of the second embodiment is not as easily removable as the lamp assembly of the first embodiment. No annular aperture is provided in the base of the second embodiment, and the lamp turret is also not included in the second embodiment. Otherwise, the top housing and the bottom housing of the preferred embodiment and the second embodiment are essentially the same.
Referring now to FIGS. 17-24, a third embodiment of the instant invention is shown with a flat wire conductor and with a non-removable lamp assembly. As described earlier, the lamp housing assembly generally comprises a bottom housing 20, a top housing 100, a lamp assembly 34, and conductor wire 68. The bottom housing 20 and the top housing 100 are coupled in interlocking engagement. Snap fit features are molded in the sides of the bottom housing or base 20 and the top housing or cover 100. These snap it features include grooves 70 as defined by the exterior of sides 22 in the base and flanges 124 as defined by sides 102 in the cover. Assisting the snap fit features in their function are alignment recesses 72 in the base 20. These recesses 72 accept guide pins 126 of the cover 100, to align the cover 100 and base 20 and constrain the longitudinal movement of the cover 100 and the base 20 relative to each other. The conductive wire harness 68 interposes the cover 100 and the base 20 as it passes through the housing assembly and is secured therein by guide pins 126.
As described above for the preferred embodiment, in this embodiment the cover has at least two sides 102 and opposite end segments 104, wherein at least one end segment defines an arcuate depression 106. The base has at least two sides 22 and opposite end segments, wherein at least one of the base end segments defines a complimentary arcuate protrusion 24, such that the cover's arcuate depression 106 receives the base's arcuate protrusion 24. The outer surfaces of both the cover and base are rounded edges to avoid puncturing the slide. As described above, the complete housing is formed by the interlocking of the cover 100 and base 20. The cover 100 includes a flange or lip 124 longitudinally disposed along the inner surface of its two sides. The base 20 includes complimentary grooves 70 along the outer surface of its two sides for receiving the flanges 124 of the cover, thereby providing a snap fit feature. As described above, assisting the snap fit feature in its function are alignment openings or recesses 72 in the base and corresponding guide pins 126 in the cover. These recesses 72 accept the guide pins 126 which protrude from the interior of the cover 100 and align the cover 100 and base 20 for assembly. In this embodiment, however, the guide pins 126 engage the flat conductive wire harness 68, piercing the flat conductor wire harness, and securely holding the wire harness within the alignment recesses. In this embodiment, the base does not contain insulation displacement terminals to receive both the flat conductor and the wire lamp leads. Rather, the wire lamp leads are soldered directly to the flat conductor. Furthermore, the cover does not contain wire guide channels, nor is there a lamp compartment with cylindrically recessed levels. However, the snap fit features of this embodiment and of the preferred embodiment are otherwise identical. Furthermore, the cover and base are also identical in that the classical S-shaped strain relief feature is formed, thus maintaining the minimum bend radii for the conductor and insulation used in the wire when the top and bottom housings are snapped together. As previously mentioned, the snap fit feature allows for easy access to the lamp if necessary.
As seen in FIGS. 18 and 23 a reflector 39 optimizes the light distribution of the lamp 36. As best seen in FIG. 23, an open chamber 123 surrounds the lamp 36 rather than the cylindrically recessed portions described in the preferred embodiment.
The instant invention has been shown and described herein in what is considered to be the most practical and preferred embodiment. It is recognized, however, that departures may be made therefrom within the scope of the invention and that obvious modifications will occur to a person skilled in the art. | A lamp assembly for installation on aircraft evacuation slides having a cover and a base that interlock to form a curvilinear and pliable lamp housing that is engineered from a plastic resin for light dispersement and durability, wherein in the preferred embodiment the base secures the lamp in a twist lock engagement for convenient replacement and where the base and cover together provide improved strain relief for the wire conductor. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2003-400612, filed Nov. 28, 2003, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an active matrix display and a manufacturing method thereof.
[0004] 2. Description of the Related Art
[0005] Displays such as light-emitting diode displays and liquid crystal displays have advantageous characteristics such as decreased thickness. For this reason, these displays have been used for office equipment, computers, and the like. Recently, organic EL (Electro-Luminescent) displays have been developed, which are superior to liquid crystal displays in the following points.
[0006] 1) An organic EL display is bright and self-emissive, and hence can realize a bright and clear display, a wide viewing angle, and reductions in power consumption, weight and thickness owing to a backlight-less structure.
[0007] 2) An organic EL display is driven by a DC constant voltage, and hence is robust against noise.
[0008] 3) The response speed of an organic EL display is on the order of μsec, whereas the response speed of a liquid crystal display is on the order of msec. Therefore, smooth moving-image display can be realized.
[0009] 4) In an organic EL display, display elements can be formed by using only solid-state elements. This makes it possible to extend the operating temperature range.
[0010] Of the above displays, an active matrix display using polysilicon thin film transistors for the respective pixels, in particular, can realize excellent display characteristics.
[0011] In such an active matrix display, however, display irregularity tends to be visually recognized due to variations in the characteristics of the polysilicon thin film transistors among the respective pixels. This phenomenon is especially noticeable when display elements change their optical characteristics in accordance with the magnitude of a current flowing therethrough, like organic EL elements, and the above polysilicon thin film transistor is a drive transistor which is connected in series with the display element.
[0012] Note that Jpn. Pat. Appln. KOKAI Publication No. 11-344723 discloses a technique associated with the present invention. According to this reference, a drive circuit to be placed around a display area is composed of a normal circuit and redundant circuit, and different laser shots are used to perform laser annealing for the formation of a polysilicon thin film transistor contained in a given normal circuit and laser annealing for the formation of a polysilicon thin film transistor contained in a redundant circuit paired with the given normal circuit. In addition, the reference describes a technique of scanning a linear beam on a pixel array in an oblique direction in a laser annealing process. The reference, however, does not describe that the relative positions of polysilicon thin film transistors with respect to pixels are made different among the pixels.
BRIEF SUMMARY OF THE INVENTION
[0013] It is an object of the present invention to provide an active matrix display whose display irregularity is hard to recognize and a method of manufacturing the same.
[0014] According to a first aspect of the present invention, there is provided an active matrix display comprising pixels arrayed in a matrix form and each including a display element and a thin film transistor which controls intensity of current flowing through the display element, wherein, in each of columns which the pixels form, the pixels are divided into a first pixel group in which the thin film transistors are arranged along a first straight line parallel with the column, and a second pixel group in which the thin film transistors are arranged along a second straight line parallel with the column and spaced apart from the first straight line.
[0015] According to a second aspect of the present invention, there is provided an active matrix display comprising pixels arrayed in a matrix form and each including a display element and a polysilicon thin film transistor, wherein, in each of columns which the pixels form, the pixels are divided into a first pixel group in which the polysilicon thin film transistors are arranged along a first straight line parallel with the column, and a second pixel group in which the polysilicon thin film transistors are arranged along a second straight line parallel with the column and spaced apart from the first straight line.
[0016] According to a third aspect of the present invention, there is provided a method of manufacturing an active matrix display comprising pixels arrayed in a matrix form and each including a display element and a thin film transistor which controls intensity of current flowing through the display element, wherein, in each of columns which the pixels form, the pixels are divided into a first pixel group in which the thin film transistors are arranged along a first straight line parallel with the column, and a second pixel group in which the thin film transistors are arranged along a second straight line parallel with the column and spaced apart from the first straight line, comprising forming semiconductor layers of the thin film transistors by irradiating an amorphous semiconductor layer with laser beam as linear beam while shifting a region of the amorphous semiconductor layer where the linear beam irradiates, wherein irradiating the amorphous semiconductor layer with laser beam is carried out such that longitudinal direction of the region is parallel with the column.
[0017] According to a fourth aspect of the present invention, there is provided a method of manufacturing an active matrix display comprising pixels arrayed in a matrix form and each including a display element and a polysilicon thin film transistor, wherein, in each of columns which the pixels form, the pixels are divided into a first pixel group in which the thin film transistors are arranged along a first straight line parallel with the column, and a second pixel group in which the thin film transistors are arranged along a second straight line parallel with the column and spaced apart from the first straight line, comprising forming polysilicon layers of the polysilicon thin film transistors by irradiating an amorphous silicon layer with laser beam as linear beam while shifting a region of the amorphous silicon layer where the linear beam irradiates, wherein irradiating the amorphous silicon layer with laser beam is carried out such that longitudinal direction of the region is parallel with the column.
[0018] According to a fifth aspect of the present invention, there is provided a method of manufacturing an active matrix display comprising pixels arrayed in a matrix form and each including a display element and a polysilicon thin film transistor, wherein, in each of rows which the pixels form, the pixels are divided into a first pixel group in which the thin film transistors are arranged along a first straight line parallel with the row, and a second pixel group in which the thin film transistors are arranged along a second straight line parallel with the row and spaced apart from the first straight line, comprising forming polysilicon layers of the polysilicon thin film transistors by irradiating an amorphous silicon layer with laser beam as linear beam while shifting a region of the amorphous silicon layer where the linear beam irradiates, wherein irradiating the amorphous silicon layer with laser beam is carried out such that longitudinal direction of the region is parallel with the row.
[0019] The term “linear beam” means a light beam which can simultaneously irradiate a linear or band-shaped region within a plane when emitting the light beam from the direction perpendicular to the plane.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0020] FIG. 1 is a plan view schematically showing an active matrix display according to an embodiment of the present invention;
[0021] FIG. 2 is a plan view showing an example of a method which can be used for the manufacture of the display shown in FIG. 1 ;
[0022] FIG. 3 is a plan view showing a laser annealing method according to a comparative example;
[0023] FIG. 4 is a plan view schematically showing an example of the arrangement of display elements which can be adopted for the display in FIG. 1 ;
[0024] FIG. 5 is a plan view schematically showing another example of the arrangement of display elements which can be adopted for the display in FIG. 1 ; and
[0025] FIGS. 6 to 11 are sectional views showing an example of a method which can be used for the manufacture of the display shown in FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
[0026] An embodiment of the present invention will be described in detail below with reference to the views of the accompanying drawing. Note that throughout the drawing, the same reference numerals denote constituent elements having same or similar functions, and a repetitive description thereof will be avoided.
[0027] FIG. 1 is a plan view schematically showing an active matrix display according to an embodiment of the present invention. FIG. 1 shows an organic EL display 1 as an example of the active matrix display according to this embodiment.
[0028] The organic EL display 1 includes an insulating substrate 10 such as a glass substrate. Pixels PX are arranged in a matrix form on one major surface of the substrate 10 . On the substrate 10 , scan signal lines 12 connected to a scan signal line driver 11 and video signal lines 14 connected to a video signal line driver 13 are so arranged as to intersect each other.
[0029] Each pixel PX includes a drive transistor Tr as a drive control element, a capacitor C, a pixel switch Sw, and an organic EL element D which is a display element. Of these components, the drive transistor Tr, capacitor C, and pixel switch Sw constitute a drive circuit. In this case, for example, the drive transistor Tr is a p-channel polysilicon thin film transistor (poly-Si TFT), and the pixel switch Sw is an n-channel poly-Si TFT. In addition, assume that pixel PX(3×M−2)a, PX(3×M−2)b, and PX(3×M−2)c emit red light, pixels PX(3×M−1)a, PX(3×M−1)b, and PX(3×M−1)c emit blue light, and pixels PX(3×M)a, PX(3×M)b, and PX(3×M)c emit green light.
[0030] The drive transistor Tr and organic EL element D are connected in series between a first power supply terminal Vdd set at a higher potential and a second power supply terminal Vss set at a lower potential. The pixel switch Sw is connected between the video signal line 14 and the gate of the drive transistor Tr. The gate of the pixel switch Sw, which serves as a control terminal, is connected to the scan signal line 12 . The capacitor C is connected between the first power supply terminal Vdd and the gate of the drive transistor Tr.
[0031] In this embodiment, in each column of the pixels PX, a pixel group of pixels PXNa, a pixel group of pixels PXNb, and a pixel group of pixels PXNc are different from one another in the relative position of the drive transistor Tr with respect to the column in the x direction. Note that the x direction is the direction crossing each column of the pixels PX, and coincides with a scan direction (to be described later). The y direction is the direction parallel to each column of the pixels PX, and coincides with the longitudinal direction of a region irradiated with a linear beam (to be described later).
[0032] A method of manufacturing the organic EL display 1 will be described next.
[0033] FIG. 2 is a plan view showing an example of a method which can be used for the manufacture of the display shown in FIG. 1 . Referring to FIG. 2 , reference symbol SI denotes a portion (to be referred to as a transistor formation portion hereinafter) of the silicon layer formed on the substrate 10 which is to be used as a semiconductor layer in which the channel, source and drain regions of the drive transistor Tr are formed. Reference numeral 50 denotes a linear beam which is a laser beam to be applied to the silicon layer in a laser annealing process.
[0034] Note that the suffix attached to each transistor formation portion SI corresponds to the suffix attached to each pixel PX in FIG. 1 . Referring to FIG. 2 , the silicon layer located on the right side of the linear beam 50 is an amorphous silicon layer, and the silicon layer located on the left side of the linear beam 50 is a crystalline silicon layer.
[0035] In this embodiment, when laser annealing is to be performed, the longitudinal direction of the linear beam 50 is made parallel with the y direction, and the linear beam 50 is scanned on the substrate 10 in the x direction at a predetermined pitch P. That is, the linear beam 50 is moved relative to the substrate 10 in the x direction at the pitch P. Typically, the position of the linear beam 50 is fixed inside an annealing apparatus, the substrate 10 on the stage is continuously moved with respect to the linear beam 50 , and the linear beam 50 is emitted in the form of pulses at a predetermined timing.
[0036] The pitch P at which the linear beam 50 is scanned is set to be smaller than the length of the pixel PX in the x direction, i.e., the pixel pitch. For example, the pitch P is set to about ⅓ the pixel pitch. In addition, the length of the linear beam 50 in the x direction is set to be larger than the pitch P at which the linear beam 50 is scanned.
[0037] When laser annealing is performed by this method, display irregularity becomes hard to be recognized. This will be described in comparison with the structure shown in FIG. 3 .
[0038] FIG. 3 is a plan view showing a laser annealing method according to a comparative example.
[0039] In the structure shown in FIG. 3 , transistor formation portions SINa, SINb, and SINc are arranged in a line in the y direction. According to the method shown in FIG. 3 , all the transistor formation portions SINa, SINb, and SINc arranged in the y direction are simultaneously irradiated with the linear beam 50 by one laser shot.
[0040] It has been found from the studies conducted by the present inventor that variation in mobility among transistors whose silicon layers have been subjected to the same laser shot during a laser annealing process is much smaller than that among transistors whose silicon layers have been subjected to different laser shots during a laser annealing process. For this reason, in the organic EL display 1 manufactured by the method shown in FIG. 3 , variation in mobility of transistor among the pixels PX arranged in the y direction is smaller than that among the pixels PX arranged in the x direction.
[0041] If the mobility of the drive transistor Tr is smaller than a design value, the luminance of the organic EL element D becomes lower than the value expected from the magnitude of a video signal supplied to the pixel PX. In contrast, if the mobility of the drive transistor Tr is larger than the design value, the luminance of the organic EL element D becomes higher than the value expected from the magnitude of a video signal supplied to the pixel PX.
[0042] According to the method shown in FIG. 3 , therefore, luminance varies among the pixels PX arranged in the x direction, whereas luminance hardly varies among the pixels PX arranged in the y direction. In the organic EL display 1 manufactured by the method shown in FIG. 3 , therefore, uniformity in luminance of the pixels arranged in the y direction makes irregularity in luminance of the pixels arranged in the x direction stand out, and hence display irregularity in the form of stripes extending in the y direction, and more specifically, luminance irregularity, tend to be visually recognized.
[0043] In contrast to this, according to the method shown in FIG. 2 , of the pixels PX arranged in the y direction, variations in luminance occur among the pixel group including the pixels PXNa, the pixel group including the pixels PXNb, and the pixel group including the pixels PXNc, in addition to variations in luminance among the pixels PX arranged in the x direction. Such variations occur randomly. Therefore, variations in luminance among the respective pixels PX are compensated for by the pixels PX adjacent to them in the x and y directions. According to this embodiment, therefore, display irregularity becomes hard to be recognized.
[0044] When the method shown in FIG. 2 is used, the obtained organic EL display 1 has a characteristic that each of the pixel group including pixels PXNa, the pixel group including pixels PXNb, and the pixel group including pixels PXNc is smaller in mobility variation of the drive transistors Tr than the column including pixels PXNa to PXNc.
[0045] In this embodiment, the organic EL elements D can be variously arranged. This will be described with reference to FIGS. 4 and 5 .
[0046] FIG. 4 is a plan view schematically showing an example of the arrangement of organic EL elements which can be used for the organic EL display shown in FIG. 1 . FIG. 5 is a plan view schematically showing another example of the arrangement of organic EL elements which can be used for the organic EL display shown in FIG. 1 . Referring to FIGS. 4 and 5 , the suffixes attached to the organic EL elements D and drive transistors Tr correspond to the suffices attached to the pixels PX shown in FIG. 1 .
[0047] In the structures shown in FIGS. 4 and 5 , for example, organic EL elements D(3×m−2)a, D(3×m−2)b, and D(3×m−2)c emit red light, organic EL elements D(3×m−1)a, D(3×m−1)b, and D(3×m−1)c emit blue light, and organic EL elements D(3×m)a, D(3×m)b, and D(3×m)c emit green light.
[0048] In the structure shown in FIG. 4 , the organic EL elements D which respectively emit red light, blue light, and green light are repeatedly arranged in this order in the x direction. That is, the organic EL elements D are arranged in the form of stripes. In contrast, in the structure shown in FIG. 5 , the organic EL elements D which respectively emit red light, blue light, and green light are arranged in an L shape. In this manner, the organic EL elements D can be arranged in various forms.
[0049] In this embodiment, as described above, each column formed by the pixels PX arranged in the y direction are composed of the three pixel groups, i.e., the pixel group including the pixels PXNa, the pixel group including the pixels PXNb, and the pixel group including the pixels PXNc. However, the number of pixel groups constituting each column is not specifically limited as long as it is two or more.
[0050] In this embodiment, the positions of the drive transistors Tr in the x direction are made different among the respective pixel groups. However, the positions of other transistors included in the pixels PX in the x direction may be made different. For example, the positions of transistors used as the pixel switches Sw in the x direction may be made different among the pixel groups. Alternatively, when another circuit arrangement is used for each pixel PX, the positions of other transistors included in the pixels PX in the x direction may made different among the pixel groups. The above effect is, however, most prominent when positions of transistors, each of which is connected in series with the organic EL element D between the first power supply terminal Vdd and the second power. supply terminal Vss, are made different among the above pixel groups.
[0051] This embodiment has exemplified the organic EL display 1 as an active matrix display. However, the above effects can be obtained even if the present invention is applied to another active matrix display. The above technique is very effective for an active matrix display using, as a display element, an element whose optical characteristics change in accordance with the magnitude of a current flowing therethrough, in particular.
[0052] An example of the present invention will be described below.
(EXAMPLE)
[0053] FIGS. 6 to 11 are sectional views showing an example of a method which can be used for the manufacture of the display shown in FIG. 1 .
[0054] In this case, an organic EL display 1 shown in FIG. 1 was manufactured by the method to be described below with reference to FIGS. 6 to 11 . Note that in the organic EL display 1 , the arrangement shown in FIG. 2 is adopted for transistor formation portions SI and the arrangement shown in FIG. 4 is adopted for organic EL elements D and drive transistors Tr.
[0055] After, for example, an SiNx layer 25 and SiO 2 layer 26 were formed as undercoat layers on a glass substrate 10 , an amorphous silicon layer having a thickness of about 50 nm was formed on the resultant structure. The amorphous silicon layer was then formed into a polysilicon layer by performing laser annealing using, for example, an XeCl excimer laser. The polysilicon layer was patterned to leave a portion corresponding to the transistor formation portion SI shown in FIG. 2 , thereby forming a polysilicon layer 151 in the shape shown in FIG. 6 .
[0056] In this case, a triplet was composed of three pixels PX arranged in the x direction. The length of the triplet in the x direction was 198 μm. That is, the length of the pixel PX in the x direction was 66 μm. In performing laser annealing, the length of a region irradiated with a linear beam 50 by one laser shot in the scan direction (x direction) was set to 440 μm, and the linear beam 50 . was scanned at a pitch of 22 μm. That is, the number of laser shots per portion was 20. In addition, a transistor formation portion SINb was shifted from a transistor formation portion SINa by 22 μm in the x direction, and a transistor formation portion SINc was shifted from the transistor formation portion SINa by 44 μm in the x direction.
[0057] As shown in FIG. 7 , a gate insulating film 152 was formed on the surface of the substrate 10 on which the polysilicon layer 151 was formed. An n + region 151 a was formed in the polysilicon layer 151 by the ion doping method.
[0058] As shown in FIG. 8 , a gate electrode 153 was formed on the gate insulating film 152 . A p + region 151 b was then formed in the polysilicon layer 151 by the ion doping method using the gate electrode 153 as a mask. In this manner, a p-channel poly-Si TFT 15 was manufactured as the drive transistor Tr. At the same time, a transistor used as the pixel switch Sw and transistors in a scan signal line driver 11 and video signal line driver 13 were manufactured. In addition, when the gate electrode 153 was formed, a video signal line 14 and the like were simultaneously formed.
[0059] Subsequently, as shown in FIG. 9 , a dielectric interlayer 16 having a thickness of 700 nm was formed on the surface of the substrate 10 on which the p-channel poly-Si TFT 15 was formed. A through hole was then formed in the dielectric interlayer 16 and gate insulating film 152 .
[0060] As shown in FIG. 10 , the video signal line 14 and a passivation film 17 were sequentially formed, and a through hole was formed in the passivation film 17 . Thereafter, a transparent electrode 18 made of ITO (Indium Tin Oxide) was formed as an anode. A hydrophilic layer 19 having an opening portion at a position corresponding to the central portion of the transparent electrode 18 was formed on the passivation film 17 . A partition insulating layer 20 was formed on the hydrophilic layer 19 . Thereafter, a buffer layer 21 containing PEDOT (polyethylenedioxythiophene) and a luminous layer 22 containing a luminescent organic compound were sequentially formed. In addition, a cathode 23 was formed on the luminous layer 22 . With the above process, an array substrate 2 was completed.
[0061] Subsequently, an ultraviolet curing resin was applied to the peripheral portion of one major surface of a glass substrate 3 serving as a sealing substrate to form a seal layer 4 . A sheet-like desiccant 5 was bonded to a recess portion formed in that surface of the sealing substrate 3 which faces the array substrate 2 . The sealing substrate 3 and array substrate 2 were then bonded to each other in an inert gas such as dry nitrogen gas such that the surface of the sealing substrate 3 on which the seal layer 4 was provided faced the surface of the array substrate 2 on which the cathode 23 was provided. The seal layer was then cured by ultraviolet light to complete the organic EL display 1 shown in FIG. 11 . In this case, the array substrate 2 was sealed by using the sealing substrate 3 . However, the array substrate 2 may be sealed by bonding a resin film to it.
[0062] The organic EL display 1 obtained by the above method was connected to an external drive circuit and power supply. The resultant structure was supported by a bezel, and a circularly polarizing plate was provided as an antireflection film on the outer surface of the array substrate 2 . When the display characteristics of the device in this state were checked, no display irregularity was visually recognized.
[0063] In this case, the organic EL display 1 is of a bottom emission type designed to extract display light from the array substrate 2 side. However, this display may be of a top emission type designed to extract display light from the sealing substrate 3 side. In this case as well, display irregularity can be prevented from being visually recognized.
(COMPARATIVE EXAMPLE)
[0064] An organic EL display 1 was manufactured by the same method as that described in the above example except that the positions of transistor formation portions SINa to SINc in the x direction were made to coincide with each other. In the comparative example, the arrangement shown in FIG. 3 was adopted for the transistor formation portions SI.
[0065] When the display characteristics of the organic EL display 1 were checked, luminance irregularity was visually recognized in the form of stripes extending in the y direction.
[0066] Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader embodiments is not limited to the specific details and representative embodiment shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. | There is provided an active matrix display including pixels arrayed in a matrix form and each including a display element and a thin film transistor. In each of columns which the pixels form, the pixels are divided into a first pixel group in which the thin film transistors are arranged along a first straight line parallel with the column, and a second pixel group in which the thin film transistors are arranged along a second straight line parallel with the column and spaced apart from the first straight line. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates generally to expansion joint fire barrier systems and, more particularly, but not by way of limitation, it relates to an improved system that utilizes a combination of thin, relatively flexible stainless steel sheets with a fire resistant fiber composition in particularly folded and reinforced configuration, such barrier combinations being capable of installation in selected multiples at an expansion joint assembly.
2. Description of the Prior Art
The prior art includes several types of attempt at providing fire or smoke barriers across expansion joints, and some of these prior designs have been used in combination with forms of expansible joint. The U.S. Pat. No. 4,517,779 in the name of Dunsworth, property of the present assignee, best characterizes the present state of the art as regards expansible fire barrier structure. This patent teaches an expansion joint assembly which includes a barrier box containing fire resistant, moisturized material, and the assembly is also utilized with an underlying expansible fire and smoke barrier comprised of METAFLEX®, a coated silica fabric. Multi-foil type thermal insulation materials have also been utilized in the past in such as radioisotope power systems. Aluminum, copper and nickel foil radiation shields have been utilized in combination with fibrous spacers in the form of plain and metal-flake opacified papers with woven fabrics selected to separate the separate radiation shields. Foil thermal radiation shields of brass, chromium, silver and gold have also been explored with varying success.
More particular to the area of building materials, a relatively thin, flexible sheeting has been constructed containing sodium silicate, glass fiber and a wire netting core. The sheeting is then coated on both sides with an epoxy resin suitable for exclusion of atmosphere and particularly carbon dioxide. A number of other materials are known for their fire resistant quality whether inherently combustion resistant or acquisitive of fire resistance characteristics through particular structural layering or assembly characteristics.
SUMMARY OF THE INVENTION
The present invention relates to improvements in fire resistant expansion joint structure, which improvements are largely directed to the inclusion of a flexible fire and smoke barrier assembly that is formed of stainless steel sheet and which may include additional fire-resistant fibrous material layered therewith. The expansion assembly includes oppositely disposed support structures in secure affixure on opposite sides of an expansion void and a centered expansion cover plate in operative association therewith. A fire and smoke barrier consisting of layered fire-resistant fibrous material and stainless steel sheeting is then rigidly secured across the void between the opposed shoulder support structures, the barrier including enough flexible expanse to continually enclose over the expansion void at both limits. The stainless steel sheeting or foil and fibrous insulation material are utilized in varying folded and/or spaced configurations, depending upon exigencies of application, and bonded reinforcing or securing rod may be used to form gripping edge configurations.
Therefore, it is an object of the present invention to provide an expansion joint barrier that exhibits greater isolation from fire, heat and smoke.
It is also an object of the invention to provide an expansion joint assembly that may be employed across a building expansion void with the capability of completely isolating a fire condition.
It is yet another object of the present invention to provide an expansion joint fire barrier system that exhibits reliable and long-life usage.
Finally, it is an object of the present invention to provide an expansible fire and smoke barrier system that is employable in various fold plys and package configurations in accordance with the exigencies of the installation.
Other objects and advantages of the invention will be evident from the following detailed description when read in conjunction with the accompanying drawings which illustrate the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view in vertical section and partial block form of an expansion joint assembly with fireproof barrier as constructed in accordance with the present invention;
FIG. 2 is a sectional view of a portion of barrier layering in attachment around a securing rod;
FIG. 3 is a view in section of an alternative form of support plate for utilization in the present invention;
FIG. 4 is a view in section of an alternative form of barrier laminate;
FIG. 5 is a view in vertical section of a alternative form of expansion joint assembly utilizing yet another type of fireproof barrier structure;
FIG. 6 illustrates in perspective and vertical section a portion of an alternative form of barrier structure;
FIG. 7 illustrates in section one form of layering relationship for the flameproof barrier structure as utilized in the invention as exemplified by FIG. 5; and
FIG. 8 illustrates in section yet another variation in layering of a flameproof barrier structure.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, a fireproof expansion joint assembly 10 is illustrated as it is operatively positioned to enclose an expansion void 12 disposed between shoulder supports 18 and 20 of adjacent building structures 14 and 16, e.g. adjoining building exterior walls, interior walls, floor sections or the like wherein expansion displacement must be accounted for. The expansion joint assembly 10 may be used on either the interior or exterior to counter expansion shifts due to wind sway, seismic disturbance vibration or other moving forces while also including an added fire barrier structure 24 in plural folds of multiple plys.
The basic expansion joint assembly is a type consisting of the shoulder sub-assemblies 18 and 20 as secured on opposite sides of expansion void 12 while including an expansion joint cover 22 slidably secured thereover. The cover 22 presents an adaptive face 26, i.e. for architectural blending or functional co-action as in the case of a floor surface, as the cover 22 is maintained in continually centered disposition relative to shoulder sub-assemblies 18 and 20. Such expansion joint assemblies particularly characterized by U.S. Pat. No. 3,183,626 in the name of Schmitt, property of the present assignee. The sub-assemblies 18 and 20 are secured to respective shoulders 14 and 16 by fasteners secured along respective axes 28 and 30. Additional fasteners secured along axes 32 and 34 provide affixure to the fire barrier structure as will be further described below.
A pair of oppositely disposed channel brackets 36 and 38 are secured to respective interior surfaces 40 and 42 of building structure shoulders 14 and 16. The retaining channel member 36 is adapted to secure a sheet portion of barrier 24 adjacent shoulder 14 and includes a right angle bracket 44 secured thereon as by welding to provide a bolt seating for a securing fastener affixed along axis 46. Additional bolt affixure is provided along axis 32 to the sub-assembly 18. On the opposite side, a securing bracket 38 formed with corner angles 38a and 38b is secured to surface 42 of shoulder 16 along such as axes 48 and/or 50 and an angle bracket (such as bracket 44) may be provided for 45° fasteners. The lower portion of securing channel 38 includes an angle bracket 52 of spring steel welded thereon to expose a retaining flange 54 in spaced relationship from channel edge 38b to define a space 56 along the length of channel 38. At assembly, the space 56 is essentially filled with an intumescent fireproof caulking compound for subsequent reception of a rod edge 60 in tight seizure through the spring opening 54.
At the upper edge of channel 38, a spring steel angle tab 62 is secured to channel edge 38a as by spot welding and the tab portion extends at an angle of about 30° toward channel 38 while terminating short of a right angle bracket 64 to form a slot opening 66 for receiving a remaining rod edge 68 of barrier 24. The angle bracket 64 is also affixed as by welding to channel 38. In assembly, the void or elongated space 70 formed by angle tab 62 and bracket 64 is filled with caulking compound 58 whereupon rod edge 68 is inserted therein through spring gap 66. A preferred form of caulking compound for us in the elongated spaces 56 and 70 is a flameproof caulking sealant known as METACAULK™, commercially available from Metalines, Inc. of Oklahoma City, Okla.
The fire barrier 24 consists of a single flexible barrier extending between rod edges 68 and 60 but having a length as required by the length along the expansion void. This may be any length from a very short expansion void to a void that extends on the order of hundreds and even thousands of feet. The width of barrier 24 is dictated by the maximum expansion to be encountered across void 12. Across the width, the barrier 24 consists of rod edge 68 extending into an upper barrier portion 72 of interleaved stainless steel sheet and alumina-silica fiber material which extends into a retainer portion 74 consisting of plural plys of the stainless steel sheeting. Retainer portion 74 then further extends into a plural ply lower barrier portion 76 of plural ply stainless steel sheet and alumina-silica material which finally terminates in rod edge 60. The one piece, multi-segment fire barrier 24 is capable of being handled readily by installment personnel in cramped or elevated spaces thereby to enable quick, permanent affixure in most facile manner.
The upper barrier portion 72 consists of three layers of stainless steel foil 78, 80 and 82 with interspaced alumina-silica paper layers 84 and 86. The stainless steel sheeting may be such as a stainless steel foil, Type 321 Annealed, that is commercially available in specified thicknesses, e.g. 0.002 inches but other thicknesses as specified may be employed. While various types of silica paper or material is available for use as the interspace layers 84 and 86, a recommended type available from The Carborundum Company of Niagara Falls, N.Y. is a type known as FIBERFRAX™ 970 paper consisting essentially of an inorganic blend of Al 2 O 3 and SiO 2 with binder substances.
The lower barrier portion 76 is shown in a three ply configuration. Thus, the stainless steel sheet ply 78 is terminated and secured as by a suitable high temperature bonding agent slightly below the retaining bracket 36 and stainless steel sheets 80 and 82 include an interspaced alumina-silica material 88 across the expansion void. The alumina-silica 88 is of a thicker material, a type of ceramic blanket that exhibits low thermal conductivity and excellent heat strength. A recommended type of material 88 is that known as FIBERFRAX™, DURABLANKET™, and alumina-silica fiber watting that is also available from The Carborundum Company. It should be understood that the plys of foil and interspaced fiber sheets may or may not be bonded together and in some cases they may be allowed to seek spaced disposition as an operational advantage. Also, some designs may only call for a single one of the upper or lower barrier portions 72 or 76.
Referring also to FIG. 2, the rod edge 60 is formed by wrapping a ply of the stainless steel foil around a rod 90 of selected diameter consonant with the proper co-action with spring opening 54. Thus, the alumina-silica blanket 88 is terminated at a spaced distance from rod 90 whereupon the enveloping stainless steel sheets 82 and 80 are bonded together by a suitable bonding agent while allowing the stainless steel sheet 80 to overlap singularly as an edge portion 92. The edge portion 92 is then tightly wrapped around in bonded affixure to secure the edge rod 90. Edge rod 90 may be any suitable rod stock of the selected diameter; however, a preferred rod material is a braided galvanized wire stock of selected diameter.
FIG. 3 illustrates a alternative form of securing channel 38 that includes a different form of spring retension device at the upper end. The lower end of securing channel 38 remains the same with an angle bracket 52 welded to define an elongated space 56 accessible through a spring opening 54. The upper end of securing gate 38 is modified in that the right angle bracket 64 (FIG. 1) is replaced by an acute angle bracket 92 secured as by welding and extending an angle portion 94 in-line with angle bracket 62 but defining a spring opening 96. Thus, in assembly the associated rod edge can be easily forced through spring opening 96 for retension within the mass of fireproof caulk 58 while the opposite rod edge is still retained in the same manner through lower spring opening 54. The choice of channel and bracket assemblies reduces to the types and sizes of installations and the ease with which installers can handle the co-acting components, sometimes at precarious positions.
The fire barrier 24 of FIG. 1 illustrates only a single type of barrier combination wherein the upper barrier 72 consists of three stainless steel foil sheets interleaved with two alumina-silica barriers, and the lower portion 76 includes two stainless steel and one alumina-silica layer. The actual spacing between barrier portions 72 and 76 generally responds to a consideration of the amount of air volume contained therebetween; that is, the depth of air space between barrier portions 72 and 76 will be proportional to the expansion gap width between interior structure walls 40 and 42.
Other combinations and numbers of layers of stainless steel foil and alumina-silica may be utilized to better accommodate specific heat and/or expansion characteristics. In the high temperatures around 2,000° F., about eighty percent of heat is radiative and the one or more folds of stainless steel foil contribute most in providing effective barrier through reflectance. At lower temperatures on the order 300° F. and up, about ninety percent of the heat experienced is convective or conductive and the insulation provided by the alumina-silica paper and/or fabrics contributes most to combatting heat effects. Most of the heat radiation lying in the infrared wavelengths is reflected by the stainless steel sheeting.
Expansion joint assemblies such as that of FIG. 1 are suitable for use in all types of expansion joint applications to provide the fire barrier capability, i.e. the system provides fire and smoke proof integrity at its point of installation in the expansion void. The assembly can be installed with maximum effectiveness in any of floor, ceiling, curtain wall, doorway or other interior applications as well as building exterior applications; however, in curtain wall applications it might be necessary to include an extra layer of stainless steel foil for attachment of thermocouples as used in the standard testing process. That is, a time versus heat test established by the International Conference of Building Officials and carried out with the ASTM No. E119 standards for fire testing.
FIG. 4 illustrates an alternative form of barrier laminate 100 that may be employed variously as a flame and smoke barrier, and that may be included in a selected number of layers in combination with such as the expansion joint assembly of FIG. 1. The barrier laminate 100 is formed of a silica fabric 102 that is covered with silicone rubber 104, and further includes a layer of stainless steel foil 106 thereover. The refractory fabric 102 may be a commercially available type known as REFRASIL™ that is coated with the silicone rubber 104 and, thereafter the stainless steel foil 106 is rolled into bonded affixure with the silicone rubber 104. Various types of refractory fabric 102 may be utilized for the underliner as the silicone rubber 104 serves to bond the stainless steel foil 106 thereover.
In operation, the barrier 100 is arrayed with the stainless steel foil 106 directed toward the possible heat or flame source so that its reflectivity makes its greatest contribution in countering the radiative heat energy. The barrier 100 combinations can also be utilized in multiple layers or spaced rows defining dead air spaces in order to provide effective flame and heat integrity.
FIG. 5 illustrates an alternative form of expansion joint assembly 110 in combination with a fire barrier 112 as disposed across an expansion void 114. The expansion joint assembly 110 is secured between adjoining deck structures 116 and 118 wherein the opposed shoulder portions have been channeled out to receive oppositely disposed mounting plates 120 and 122 as secured in the deck shoulders by anchor fasteners 124 and 126, respectively. It should be understood that such joint assemblies are necessarily of elongated shape such that the mounting plates 120 and 122 are elongated, and an attendant plurality of anchor bolts 124 and 126 are required along the length of the structure.
Oppositely disposed support sub-assemblies 128 and 130 are then secured to support the centered cover plate 132. Subassembly 128 includes an angle bracket 134 secured as by welding along mounting plate 120 to support a cam guide 136 as affixed therealong by a plurality of bolts 138. In like manner, the opposite side sub-assembly 130 includes an angle bracket 148 supporting a cam guide 150 as secured therealong by a plurality of bolts 152. The deck structure, adjacent the respective subassemblies 128 and 130, is filled in by grout as at 154 and 156. The cover plate 132 is then secured thereover as by bolt fasteners 158, and cover 132 is centrally retained by means of rotatable centering bar 160 and oppositely disposed cam rollers 162 and 164 riding within respective cam guides 136 and 150.
The fire barrier 112 again may consist of an upper barrier 166 and a lower barrier 168 that are separated by a pre-defined distance to provide requisite dead air space therebetween. The upper barrier 166 consists of a plurality of stainless steel sheets with interleaved layers of refractory paper, e.g. alumina-silica paper as before described. Any number of plys of stainless steel foil and refractory material may be selected as barrier 112 illustrates three layers of stainless steel sheeting 170, 172 and 174 and interleaved layers of refractory material 176 and 178. The upper barrier 166 is fold-formed for flexible movement with the refractory material terminating at fold breaks 180 and 182, the stainless steel sheet portions extending to provided securing tab portions. In like manner, the lower barrier 168 consists of a pair of stainless steel sheets 184 and 186 with an interleaved layer of refractory material 188 as the stainless steel ends only extend upward to form securing tabs.
A plurality of securing plates formed of such as 16-gauge sheet metal are utilized to anchor and maintain the barriers 166 and 168 in proper disposition. A right angle securing plate 190 is secured by a bolt 192 to clamp the foil tab ends 184, 186 above a break fold 194. In like manner, a clamping plate 196 is secured as by bolts 152 to retain the opposite sides of stainless steel sheets 184 and 186 adjacent the surface of deck portion 118. The upper stainless steel outer tab portions of upper barrier 166 are retained in similar manner. A clamping plate 200 and bolts 192 secure one side of stainless steel sheeting 170, 172 and 174 while a clamping plate 202 performs the similar function relative to securing bolts 152 on the opposite side.
The embodiment of FIG. 5 again illustrates the combination wherein an upper barrier consists of three layers of stainless steel sheeting with interleaving of two plys of refractory paper, and the lower barrier 168 consists of two layers of stainless steel sheeting including a single ply of refractory blanket material. The paper and/or blanket material may be the FIBERFRAX™ type of material as previously described or other comparable refractory materials. Also, the stainless steel sheeting is preferably a relatively thin stainless steel foil, the weight of the barrier becoming a very important consideration in most applications and especially those wherein handling and installation is required at high altitude or other precarious positions. The barriers 166 and/or 168 may be assembled so that the individual constituent layers are suitably bonded together or they may be non-bonded to allow relative movement each to the other. In some cases it may be desirable for the individual layer components to seek their own relative disposition while providing some interior dead air space.
FIG. 6 illustrates in enlarged view a portion of barrier material which amounts to a continuation of the teachings of FIG. 4. That is, an interior refractory material 210, which may be refractory fabric such as REFRASIL® or other fabric or blanket materials, is hot coated on each side with a silicone rubber coating 212 and 214 and opposite stainless steel foil sheets 216 and 218 are bonded thereon. FIG. 7 illustrates in enlarged form the lower barrier 168 of FIG. 5 wherein the barrier is formed with outer stainless steel sheets 184 and 186 enclosing an inner sheet of refractory blanket 188 that extends only between the fold breaks 220 and 222. The edge or tab portions 224 and 226 of the stainless steel sheets then extend as required for clamping or other affixure across the expansion gap. The edges may be formed with overlap and bonding of one foil sheet relative to the other, e.g. edges of foil sheet 186 are folded over top sheet 184. The plys of the barrier of FIG. 7 may be bonded, as by the silicone rubber coating (FIG. 6) or by other commercially available forms of bonding agent, or the plys may be expressly left unbonded to enable greater flexibility of the barrier.
FIG. 8 illustrates yet another combination, albeit a simplest form of two-ply barrier wherein a sheet of stainless steel foil or sheeting 230 is employed with a layer of refractory or blanket 232. Sheet 230 and layer 232 may or may not be bonded together, and the orientation of the foil side of the barrier will vary in accordance with applications. The two-ply barrier 228 can be effective to provide a high efficiency, light weight, reduced cost heat and flame barrier that is suitable for many construction applications.
The foregoing discloses a novel combination of expansion joint assembly and fire and smoke barrier. The barrier utilizes various combinations of stainless steel foil with layers of refractory material, i.e. papers, fabrics and blanket materials, thereby to provide an extremely versatile flame, heat and smoke barrier that is light in weight, easy to install and much reduced in cost in relation to the benefits derived and comparable structure. It should be understood that Applicants do not intend in any way to limit the obvious versatility of the invention. That is, the combinations or plys of stainless steel sheeting and refractory material, and their particular stacking or combining, may be varied over a wide range of possible combinations to achieve specifically desirable fire barrier effects whether it be from the safety standpoint, the cost effectiveness standpoint or ease of installation.
Changes may be made in the combination and arrangment of elements as heretofore set forth in the specification and shown in the drawings; it being understood that changes may be made in the embodiments disclosed without departing from the spirit and scope of the invention as defined in the following claims. | Apparatus for fireproof cover of expansion voids consisting of expansion joint cover structure spanning the expansion void and supporting at least one layer of stainless steel foil and other refractory material in continual coverage across said void. | 4 |
CROSS REFERENCES TO RELATED APPLICATIONS
Pursuant to 35 U.S.C. 119, this application is related to and claims the benefit of the earlier filing date of provisional application having Ser. No. 61/503,390, filed on Jun. 30, 2011, and entitled “Door Dampening Device and System,” the contents of which are hereby incorporated by reference herein in its entirety.
BACKGROUND
1. Field of the Invention
The present invention relates generally to doors and door closure apparatus and, more particularly, to a device for dampening the swinging open of a door using a linear slider.
2. Description of the Related Art
Doors or access covers, particularly those that are vertically mounted, typically lend themselves to being opened rapidly due to their weight and gravity. For example, when a user opens the door to access the interior of a machine and the user does not support the door through its rotation to the fully opened position, the tendency is for the door to swing open quickly. This may cause a shock load that can damage the hinge and/or the door itself. Also, an abruptly opening door gives an undesirable impression to the user that the product is cheap or of poor quality. Consequently, various damping devices have been constructed for attenuating the swinging open of a door. Some of the more common devices used to attenuate the rotational movement of a door use a torsional spring that is connected to the hinge and that provides a damping force when the door is opened or closed. Another common door damping device is a door engaging with a rack gear that attenuates the rotational movement of the door. However, such devices do not lend themselves especially useful in applications that have a small space to accommodate the damping device. If they are to be used, the footprint size of the product would increase which consequently contributes to additional cost to make the product.
Based upon the foregoing, there is a need to provide a reliable damping device for attenuating the swinging motion of a door that is compact, simple in design and inexpensive to manufacture.
SUMMARY
Example embodiments of the disclosure provide a device for attenuating movement of a door from a closed position to an open position. According to example embodiments, a housing having a first surface spaced apart from a second surface is provided to define a sliding path for an elongated sliding member. The elongated sliding member engages, such as frictionally engages, with at least one of the first surface and the second surface when the elongated member undergoes sliding movement in a first direction. A connecting member having one end thereof connected to the door and the other end to the elongated sliding member is provided so that opening of the door moves the sliding member in the first direction. Damping material is disposed between the at least one of the first surface and the second surface and the elongated sliding member. The damping material applies surface tension forces to the elongated sliding member when sliding in the first direction such that movement of the door from the closed position to the open position is attenuated or dampened.
BRIEF DESCRIPTION OF THE DRAWINGS
The above-mentioned and other features and advantages of the various embodiments of the invention, and the manner of attaining them, will become more apparent and will be better understood by reference to the accompanying drawings, wherein:
FIG. 1A is a perspective view of an embodiment of an imaging device with its access door in the closed position;
FIG. 1B is a perspective view of the embodiment of an imaging device of FIG. 1B with the access door in the open position;
FIG. 2A is a perspective underside view of a corner, front portion of the imaging device of FIG. 1A ;
FIG. 2B is a perspective underside view of a corner, front portion of the imaging device of FIG. 1B with the slide cover and the biasing member removed;
FIG. 3 is a perspective view of the dampening assembly of FIGS. 2A and 2B ;
FIG. 4 is a side section view of a portion of the access door and base frame assembly of the imaging device of FIGS. 1A and 1B with the access door in the closed position;
FIG. 5 is a side section view of a portion of the access door and base frame assembly of the imaging device of FIGS. 1A and 1B with the access door in the open position;
FIG. 6A is a side section view of a portion of the access door and base frame assembly of FIGS. 1A and 1B with the access door rotated about 75 degrees from the closed position;
FIG. 6B is a side section view of a portion of the access door and base frame assembly of FIGS. 1A and 1B with the access door rotated about 90 degrees from the closed position;
FIG. 7A is a side section view of a portion of the access door and base frame assembly with the access door rotated about 15 degrees from the open position;
FIG. 7B is a side section view of a portion of the access door and base frame assembly with the access door rotated to the closed position; and
FIG. 8 is a side section view of a portion of the access door and base frame assembly of the imaging device of FIGS. 1A and 1B with the access door in the closed position, according to another example embodiment.
DETAILED DESCRIPTION
It is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Further, the terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.
Reference will now be made in detail to the example embodiments, as illustrated in the accompanying drawings. Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts.
FIGS. 1A and 1B illustrate a perspective view of an imaging device 10 embodying an example embodiment. Imaging device 10 , which may be a standalone imaging device, includes a housing 15 having an upper front portion 20 including an image capture window 25 . Image capture window 25 may be constructed from a rigid, transparent and/or translucent material, such as glass. Lid 30 may be pivotably connected along a bottom edge 35 thereof to the housing 15 via hinges or the like (not shown) to allow the lid 30 to swing relative to the image capture window 25 so that the lid 30 may cover the image capture window 25 in a closed position and uncover the image capture window 25 in an open position. FIGS. 1A and 1B illustrate lid 30 disposed in the closed position.
As shown, imaging device 10 may include an access cover 50 pivotably connected to a lower front portion 40 of the housing 15 . The access cover 50 may be pivotably connected along a bottom edge 45 thereof to the lower front portion 40 of the housing 15 via hinges 55 , 56 , or the like to allow the access cover 50 to swing relative to the lower front portion 40 so that the access cover 50 may cover an interior 70 in a closed position and uncover the interior 70 in an open position. FIG. 1A illustrates the access cover 50 disposed in the closed position and FIG. 1B illustrates the access cover 50 in the open position.
According to an example embodiment, upper and lower front portions 20 , 40 may be disposed in an inclined position at an acute angle relative to the horizontal. The back portion of the imaging device 10 may have an input media tray 80 that may retain one or more print media sheets therein. A media output area 85 may be positioned along a lower part of lower front portion 40 .
As illustrated in FIG. 1B , according to an example embodiment the access cover 50 may be opened to access a tank install area 71 and to access a secondary cover 78 for removing jammed sheets of media and removing and installing a printhead. An ink tank assembly 72 having a plurality of ink cartridges as well as a printhead assembly (not shown) may be in tank install area 71 .
FIGS. 2A and 2B show perspective underside views of a lower, corner portion of the access cover 50 and the base frame assembly 100 of the imaging device 10 . Base frame assembly 100 includes a housing 112 and an attenuating device 110 for dampening the rotational movement of the access cover 50 as it moves from the closed position (as shown in FIG. 1A ) to the open position (as shown in FIG. 1B ). Attenuating device 110 may include elongated sliding member 130 ( FIG. 2B ) disposed within housing 112 and operatively coupled to the access cover 50 so as to undergo substantially linear sliding movement in a forward direction (i.e., towards the front of imaging device 10 ) during movement of the access cover 50 from the closed position to the open position, and movement in a direction opposite the first direction when access cover 50 is moved from the open position to the closed position. Housing 112 may include a floor portion 106 (shown in FIG. 2A , whereas FIG. 2B shows base frame assembly without floor portion 106 so as to illustrate the positioning of sliding member 130 ) having an inner surface for engaging with sliding member 130 , creating surface tension forces acting thereon and resisting movement of sliding member 130 in the forward direction.
Attenuating device 110 may further include a biasing member 120 which may further resist the forward movement of the elongated sliding member 130 . In one example embodiment as depicted in FIG. 2A , the biasing member 120 may be a compression spring having a first end 122 ( FIG. 5 ) receivably mounted to a post 103 ( FIG. 2B , which shows post 103 with biasing member 120 removed) extending from a wall 102 positioned forwardly of sliding member 130 , and a second end 124 ( FIG. 5 ) receivably mounted to a post 133 on a front end 132 of the elongated sliding member 130 (best seen in FIG. 3 ). In another contemplated embodiment shown in FIG. 8 , the biasing member 120 may be a tension spring positioned rearwardly of the sliding member 130 , having one end connected to a rear end 134 of the elongated sliding member 130 and a second end to a wall 102 . Like biasing member 120 , the tension spring provides resistance against the movement of the elongated sliding member 130 in the forward direction.
Housing 112 , which may form an enclosure at least partly around sliding member 130 , may include the floor portion 106 fixably mounted by appropriate fastening means such as screws, on the base frame assembly 100 . Housing 112 provides a space between the floor portion 106 and the base frame assembly 100 to accommodate the elongated sliding member 130 at least partly therein. Elongated sliding member 130 of attenuating device 110 may be positioned above floor portion 106 , as indicated in FIG. 4 .
Attenuating device 110 may further include connecting member 150 having a front end 152 coupled to front end 132 of elongated sliding member 130 and a rear end 154 coupled to the access cover 50 ( FIG. 4 ). In one example embodiment, the connecting member 150 may be a substantially rigid wire form made of stainless steel material or like material. Each end 152 , 154 of the connecting member 150 may have a hook portion. As shown in FIG. 3 , the hook portion of front end 152 may be received in the aperture at front end 132 of the elongated sliding member 130 such that the hook portion of front end 152 straddles and prevents withdrawal of the connecting member 150 and disconnection from the aperture of the front end 132 of the elongated sliding member 130 . Similarly, the hook portion of rear end 154 is received in an arcuate slot 52 at the pivoting end 54 of the access cover 50 ( FIGS. 4 and 5 ) such that the hook portion of rear end 154 prevents withdrawal of the connecting member 150 and disconnection from the arcuate slot 52 .
Referring to FIG. 4 , a layer of damping grease 115 may be provided in the gap between the engaging surface of the ceiling portion 113 of housing 112 and the upper contacting surface 138 of the elongated sliding member 130 , and/or in the gap between the lower contacting surface 140 of the elongated sliding member 130 and the floor portion 106 . In an example embodiment, damping grease 115 is a fluorocarbon gel, such as fluorocarbon gel 868VH made by Nye Lubricants, Inc. of Fairhaven, Mass. It is understood, however, that damping grease 115 may be other lubricants or fluorocarbon gels. As shown in FIG. 3 , the elongated sliding member 130 , in one embodiment, may have a plurality of grooves 145 formed laterally across the upper contacting surface 138 and/or the lower contacting surface 140 of sliding member 130 . Grooves 145 serve to retain damping grease 115 therein. In an alternative embodiment, a plurality of grooves (not shown) may be formed laterally across the engaging surface of the floor portion 106 and/or the engaging surface of the base frame assembly 100 . Though grooves 145 are depicted in FIG. 3 as being substantially linear and laterally disposed across upper contacting surface 138 , it is understood that grooves 145 may have any of a number of different shapes so long as such shaped grooves serve to retain damping grease 115 .
It will be understood that, when the access cover 50 moves from the closed position (shown in FIG. 4 ) to the open position ( FIG. 5 ), the rotation of cover 50 substantially about axis 58 pulls connecting member 150 forwardly toward a front of imaging device 10 such that the elongated sliding member 130 advances in the forward direction indicated by arrow A (shown in FIG. 4 ). However, the surface tension forces applied to sliding member 130 by floor portion 106 and/or base frame assembly 100 , at least partly due to the presence of damping grease 115 as explained above, are sufficient to slow down or otherwise dampen the forward movement of the elongated sliding member 130 , thereby damping or attenuating rotational movement of the access cover 50 to effectuate smooth and non-abrupt opening movement thereof. Further, as mentioned above, the biasing member 120 may also provide a force resisting the forward movement of elongated sliding member 130 which also serves to attenuate the forward movement of the elongated sliding member 130 and opening movement of access cover 50 in a substantially constant, non-abrupt, and smooth motion.
In one example embodiment, a breakaway feature is provided to at least partly relieve the stress at the pivoting member 57 of base frame assembly 100 when access cover 50 is fully opened. As can readily seen from comparing FIGS. 6A and 7B , the position of the hook portion of rear end 154 is in a first portion 53 A of the arcuate slot 52 of the access cover 50 . It will be understood, therefore, that from the closed position (shown in FIG. 7B ) up to the time when the access cover 50 is rotated about 75 degrees from the vertical, the torque on the hinges 55 , 56 ( FIG. 1B ) increases due to the unsupported weight of the access cover 50 and the spring force exerted by the biasing member 120 . Furthermore, a user may accidentally force the access cover 50 to rotate beyond its intended operating window and/or beyond its intended, fully open position and could damage the hinges 55 , 56 as a result.
The breakaway feature enables the access cover 50 to release at least some of the stress experienced by hinges 55 , 56 . As shown in FIG. 6A , when the door is opened about 75 degrees from the closed or substantially vertical position, the hook portion of rear end 154 of connecting member 150 is positioned to engage the first portion 53 A of the arcuate slot 52 . Access cover 50 is provided with a claw member 60 for engaging a wall portion 107 of base frame assembly 100 . At an opening of about 75 degrees, the claw member 60 flexes as it moves against the wall portion 107 from the rear side 108 until the claw member 60 eases out of the front side 109 of wall portion 107 at an opening of about 90 degrees ( FIG. 6B ). As the claw member 60 eases out of engagement with the wall portion 107 , the claw member 60 springs back or otherwise resiliently returns to its original form such that an edge surface 62 of the claw member 60 abuts against the front side 109 of wall portion 107 . The springing, resilient action of the claw member 60 causes movement of the hook portion 156 of rear end 154 to move from the first portion 53 A to the second portion 53 B of the arcuate slot 52 as shown in FIG. 6B . As a result, some of the stress on the hinges 55 , 56 is released by allowing the biasing member 120 to decompress.
To return the access cover 50 back to the closed position, the user applies a force to rotate the access cover 50 , allowing the hook portion of rear end 154 to move from second portion 53 B, as shown in FIG. 7A , back to the first portion 53 A of the arcuate slot 52 , as shown in FIG. 7B . Claw member 60 flexes back into engagement and then out of engagement with the wall 107 from the front side 109 to the rear side 108 until it reaches its original position. The rotational movement of the access cover 50 back to the closed position allows the biasing member 120 to decompress and to push the elongated sliding member 130 in the direction opposite arrow A. In an example embodiment, magnets (not shown) may be used to secure the access cover 50 in the closed position although latches or other mechanisms may be used.
The foregoing description of several methods and embodiments has been presented for purposes of illustration. It is not intended to be exhaustive or to limit the invention to the precise acts and/or forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be defined by the claims appended hereto. | A device for attenuating movement of a door includes a housing having a first surface spaced apart from a second surface for defining a sliding path for an elongated sliding member. The elongated sliding member engages with at least one of the first and second surfaces when the elongated member slides in a first direction. A connecting member having a first end connected to the door and the other end to the elongated sliding member is provided so that opening of the door moves the sliding member in the first direction. Damping material is disposed between the elongated sliding member and at least one of the first and second surfaces. The damping material applies surface tension forces to the elongated sliding member when sliding in the first direction such that movement of the door attenuates or dampens the movement of the door. | 4 |
CROSS-REFERENCES TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 10/818,698, entitled “MULTISPECTRAL BIOMETRIC SENSOR,” filed Apr. 5, 2004 by Robert K. Rowe et al. (“the parent application”), the entire disclosure of which is incorporated herein by reference for all purposes. The parent application is a nonprovisional of, and claims the benefit of the filing date of each of the following provisional applications, the entire disclosure of each of which is incorporated herein by reference for all purposes: U.S. Prov. Pat. Appl. No. 60/460,247, entitled “NONINVASIVE ALCOHOL MONITOR,” filed Apr. 4, 2003; U.S. Prov. Pat. Appl. No. 60/483,281, entitled “HYPERSPECTRAL FINGERPRINT READER,” filed Jun. 27, 2003 by Robert K. Rowe et al.; U.S. Prov. Pat. Appl. No. 60/504,594, entitled “HYPERSPECTRAL FINGERPRINTING,” filed Sep. 18, 2003; and U.S. Prov. Pat. Appl. No. 60/552,662, entitled “OPTICAL SKIN SENSOR FOR BIOMETRICS,” filed Mar. 10, 2004.
This application is also related to U.S. patent application Ser. No. 09/874,740, entitled “APPARATUS AND METHOD OF BIOMETRIC DETERMINATION USING SPECIALIZED OPTICAL SPECTROSCOPY SYSTEM,” filed Jun. 5, 2001, the entire disclosures of both of which are incorporated herein by reference for all purposes
BACKGROUND OF THE INVENTION
This application relates generally to biometrics. More specifically, this application relates to methods and systems for performing biometric measurements with a multispectral imaging sensor, and to methods and systems for measuring in vivo levels of alcohol or other analytes.
“Biometrics” refers generally to the statistical analysis of characteristics of living bodies. One category of biometrics includes “biometric identification,” which commonly operates under one of two modes to provide automatic identification of people or to verify purported identities of people. Biometric sensing technologies measure the physical features or behavioral characteristics of a person and compare those features to similar prerecorded measurements to determine whether there is a match. Physical features that are commonly used for biometric identification include faces, irises, hand geometry, vein structure, and fingerprint patterns, which is the most prevalent of all biometric-identification features. Current methods for analyzing collected fingerprints include optical, capacitive, radio-frequency, thermal, ultrasonic, and several other less common techniques.
Most of the fingerprint-collection methods rely on measuring characteristics of the skin at or very near the surface of a finger. In particular, optical fingerprint readers typically rely on the presence or absence of a difference in the index of refraction between the sensor platen and the finger placed on it. When an air-filled valley of the fingerprint is above a particular location of the platen, total internal reflectance (“TIR”) occurs in the platen because of the air-platen index difference. Alternatively, if skin of the proper index of refraction is in optical contact with the platen, then the TIR at this location is “frustrated,” allowing light to traverse the platen-skin interface. A map of the differences in TIR across the region where the finger is touching the platen forms the basis for a conventional optical fingerprint reading. There are a number of optical arrangements used to detect this variation of the optical interface in both bright-field and dark-field optical arrangements. Commonly, a single, quasimonochromatic beam of light is used to perform this TIR-based measurement.
There also exists non-TIR optical fingerprint sensors. In most cases, these sensors rely on some arrangement of quasimonochromatic light to illuminate the front, sides, or back of a fingertip, causing the light to diffuse through the skin. The fingerprint image is formed due to the differences in light transmission across the skin-platen boundary for the ridge and valleys. The difference in optical transmission are due to changes in the Fresnel reflection characteristics due to the presence or absence of any intermediate air gap in the valleys, as known to one of familiarity in the art.
Optical fingerprint readers are particularly susceptible to image quality problems due to non-ideal conditions. If the skin is overly dry, the index match with the platen will be compromised, resulting in poor image contrast. Similarly, if the finger is very wet, the valleys may fill with water, causing an optical coupling to occur all across the fingerprint region and greatly reducing image contrast. Similar effects may occur if the pressure of the finger on the platen is too little or too great, the skin or sensor is dirty, the skin is aged and/or worn, or overly fine features are present such as may be the case for certain ethnic groups and in very young children. These effects decrease image quality and thereby decrease the overall performance of the fingerprint sensor. In some cases, commercial optical fingerprint readers incorporate a thin membrane of soft material such as silicone to help mitigate these effects and restore performance. As a soft material, the membrane is subject to damage, wear, and contamination, limiting the use of the sensor without maintenance.
Biometric sensors, particularly fingerprint biometric sensors, are generally prone to being defeated by various forms of spoof samples. In the case of fingerprint readers, a variety of methods are known in the art for presenting readers with a fingerprint pattern of an authorized user that is embedded in some kind of inanimate material such as paper, gelatin, epoxy, latex, and the like. Thus, even if a fingerprint reader can be considered to reliably determine the presence or absence of a matching fingerprint pattern, it is also critical to the overall system security to ensure that the matching pattern is being acquired from a genuine, living finger, which may be difficult to ascertain with many common sensors.
Another way in which some biometric systems may be defeated is through the use of a replay attack. In this scenario, an intruder records the signals coming from the sensor when an authorized user is using the system. At a later time, the intruder manipulates the sensor system such that the prerecorded authorized signals may be injected into the system, thereby bypassing the sensor itself and gaining access to the system secured by the biometric.
A common approach to making biometric sensors more robust, more secure, and less error-prone is to combine sources of biometric signals using an approach sometimes referred to in the art as using “dual,” “combinatoric,” “layered,” “fused,” or “multifactor biometric sensing. To provide enhanced security in this way, biometric technologies are combined in such a way that different technologies measure the same portion of the body at the same time and are resistant to being defeated by using different samples or techniques to defeat the different sensors that are combined. When technologies are combined in a way that they view the same part of the body they are referred to as being “tightly coupled.”
The accuracy of noninvasive optical measurements of physiological analytes such as glucose, alcohol, hemoglobin, urea, and cholesterol can be adversely affected by variation of the skin tissue. In some cases it is advantageous to measure one or more physiological analytes in conjunction with a biometric measurement. Such dual measurement has potential interest and application to both commercial and law-enforcement markets.
There is accordingly a general need in the art for improved methods and systems for biometric sensing and analyte estimation using multispectral imaging systems and methods.
BRIEF SUMMARY OF THE INVENTION
Embodiments of the invention thus provide methods and systems for biometric sensing and physiological analyte estimation. The embodiments of the present invention collect multispectral image data that represent spatio-spectral information from multiple skin features at various depths and positions within an image volume. The information from the different features can be advantageously combined to provide for methods of biometric identification, including identity verification. As well, the multispectral image data may be processed to provide information about the authenticity or liveness state of a sample. The multispectral image data may also be used to ascertain information about the presence and amount of particular physiological analytes that may be present in the tissue at the image location.
Embodiments of the invention provide methods and systems for assessing skin composition and structure in a certain location on the body using optical techniques. When light of a particular wavelength enters the skin, it is subject to optical interactions that include absorbance and scatter. Due to the optical scatter, a portion of the light will generally be diffusely reflected from the skin after entering the skin at the illumination point. An image of the light thus reflected contains information about the portion of the skin that the light passes through while traveling from the point of illumination to detection. Different wavelengths of light will interact with skin differently. Due to the properties of certain skin components, certain wavelengths of light will interact more or less strongly with certain components and structures. As well, certain wavelengths of light will travel greater distances into and through the skin before being scattered back out of the skin and detected. Accurate measurement of the spatial characteristics of light that is diffusely reflected from skin thus contains information about the components and structures in the skin that interacted with light of a certain wavelength. Similar measurements made using light of multiple and different illumination wavelengths provides additional information about the skin composition and structure.
In one set of embodiments, a sensor system is provided. An illumination subsystem is disposed to provide light at a plurality of discrete wavelengths to a skin site of an individual. A detection subsystem is disposed to receive light scattered from the skin site. A computational unit is interfaced with the detection system. The computational unit has instructions for deriving a spatially distributed multispectral image from the received light at the plurality of discrete wavelengths. The computational unit also has instructions for comparing the derived multispectral image with a database of multispectral images to identify the individual.
The identification of the individual may be performed differently in different embodiments. In one embodiment, the instructions for comparing the derived multispectral image with the database comprise instructions for searching the database for an entry identifying a multispectral image consistent with the derived multispectral image. In another embodiment, the instructions for comparing the derived multispectral image with the database comprise instructions for comparing the derived multispectral image with the multispectral image at an entry of the database corresponding to a purported identity of the individual to verify the purported identity.
The illumination subsystem may comprise a light source that provides the light to the plurality of discrete wavelengths, and illumination optics to direct the light to the skin site. In some instances, a scanner mechanism may also be provided to scan the light in a specified pattern. The light source may comprise a plurality of quasimonochromatic light sources, such as LEDs or laser diodes. Alternatively, the light source may comprise a broadband light source, such as an incandescent bulb or glowbar, and a filter disposed to filter light emitted from the broad band source. The filter may comprise a continuously variable filter in one embodiment. In some cases, the detection system may comprise a light detector, an optically dispersive element, and detection optics. The optically dispersive element is disposed to separate wavelength components of the received light, and the detection optics direct the received light to the light detector. In one embodiment, both the illumination and detection subsystems comprise a polarizer. The polarizers may be circular polarizers, linear polarizers, or a combination. In the case of linear polarizers, the polarizers may be substantially crossed relative to each other.
The sensor system may comprise a platen to contact the skin site, or the sensor system may be configured for noncontact operation. The platen may be adapted for the skin site to be swiped over a surface of the platen. In one such embodiment, the platen comprises an optically clear roller that the finger can roll across with a swipe motion. In such an embodiment, the instructions for deriving the spatially distributed multispectral image include instructions for building up the multispectral image from light received from different portions of the skin site as the skin site is rolled.
The illumination subsystem may comprise a plurality of illumination subsystems. In different embodiments, the plurality of discrete wavelengths are provided sequentially or are provided substantially simultaneously and with an identifiable encoding. Suitable wavelengths for the plurality of discrete wavelengths include wavelengths between about 400 nm and 2.5 μm.
In some embodiments, the sensor system may have additional components to allow the estimation of other parameters. For instance, in one embodiment, the computational system further has instructions for deriving spectral-distribution characteristics from the received light. Such spectral-distribution characteristics may be used to determine an analyte concentration in tissue below a surface of the skin site, such as a concentration of alcohol, glucose, hemoglobin, urea, and cholesterol. In another embodiment, the computational system further has instructions for determining a liveness state from the derived spectral-distribution characteristics.
In a second set of embodiments, methods are provided for identifying an individual. A skin site of the individual is illuminated at a plurality of discrete wavelengths. Light scattered from the skin site is received. A spatially distributed multispectral image is derived from the received light at the plurality of discrete wavelengths. The derived multispectral image data or one or more of its parts are compared with a database of derived multispectral images. Various of the embodiments include aspects discussed above in connection with embodiments for the sensor system. In some instances, the methods allow generation of measurement sequences that are not constant for all samples. In one embodiment, a sequence of illumination wavelengths is changed between measurements. In another embodiment, the selection of which illumination wavelengths are used to illuminate the skin are changed between measurements.
In a third set of embodiments, a sensor system is provided. An illumination subsystem is disposed to provide light at a plurality of discrete wavelengths to a sample. A detection subsystem is disposed to receive light scattered within tissue of the sample. A computational unit is interfaced with the detection subsystem. The computational unit has instructions for deriving multispectral characteristics of the received light at the plurality of distinct wavelengths. The computational unit also has instructions for determining a liveness state of the tissue from the derived multispectral characteristics. In one such embodiment, the liveness state is determined by pixelating spatial distributions of the derived multispectral characteristics. An multivariate factor analysis is performed on a matrix having entries in a first dimension corresponding to a pixel of a pixelated spatial distribution and having entries in a second dimension corresponding to one of the plurality of distinct wavelengths. In addition, various of the embodiments may include aspects discussed above in connection embodiments for other sensor systems.
In a fourth set of embodiments, a method is provided for determining a liveness state of a sample. The sample is illuminated with light at a plurality of discrete wavelengths. Light scattered within tissue of the sample is received. Multispectral characteristics of the received light are derived at the plurality of discrete wavelengths. A liveness state of the tissue is determined from the derived multispectral characteristics to ensure that the derived characteristics of the sample are consistent with the characteristics anticipated from an authentic sample. Various of the embodiments may include aspects discussed above for other sets of embodiments.
In a fifth set of embodiments, a method is provided for determining a blood-alcohol level of an individual. Electromagnetic radiation emanating from tissue of the individual in response to propagation of electromagnetic radiation into the tissue of the individual is received. Spectral properties of the received electromagnetic radiation are analyzed. The blood-alcohol level is determined from the analyzed spectral properties.
The spectral properties may be analyzed over specific wavelength ranges in specific embodiments. For example, in one embodiment amplitudes of the received electromagnetic radiation are determined within a wavelength range of 2.1-2.5 μm. This range includes the specific wavelengths of 2.23 μm, 2.26 μm, 2.28 μm, 2.30 μm, 2.32 μm, 2.25 μm, and 2.38 μm, at one or more of which amplitudes may be determined in a specific embodiment. In another embodiment, amplitudes of the received electromagnetic radiation are determined within a wavelength range of 1.5-1.9 μm. This range includes 1.67 μm, 1.69 μm, 1.71 μm, 1.73 μm, 1.74 μm 1.76 μm and 1.78 μm, at one or more of which amplitudes may be determined in a specific embodiment.
In a sixth set of embodiments, an apparatus is provided for determining a blood-alcohol level of an individual. A receiver is adapted to receive electromagnetic radiation emanating from tissue of the individual in response to propagation of electromagnetic radiation into the tissue of the individual. A computer readable-storage medium is coupled with a process and has a computer-readable program embodied therein for directing operation of the processor. The computer-readable program includes instructions for analyzing spectral properties of the received electromagnetic radiation and instructions for determining the blood-alcohol level from the analyzed spectral properties.
In some embodiments, the methods and/or apparatus of the invention may be embodied in devices, such as motor vehicles, whose access and/or operation may be dependent on the determination of the blood-alcohol level. Furthermore, the use of alcohol monitoring may be coupled with biometric identifications in some embodiments. For example, access and/or operation of devices embodying combined alcohol-monitoring and biometric-identification devices may be dependent on a combination of alcohol-monitoring and biometric-identification determinations. In one embodiment, the biometric identification is performed with the same multispectral data used to perform the alcohol estimation.
BRIEF DESCRIPTION OF THE DRAWINGS
A further understanding of the nature and advantages of the present invention may be realized by reference to the remaining portions of the specification and the drawings wherein like reference labels are used throughout the several drawings to refer to similar components. In some instances, reference labels include a numerical portion followed by a latin-letter suffix; reference to only the numerical portion of reference labels is intended to refer collectively to all reference labels that have that numerical portion but different latin-letter suffices.
FIG. 1 provides a front view of a multispectral biometric sensor in one embodiment of the invention;
FIG. 2A provides a side view of a multispectral biometric sensor shown in one embodiment;
FIG. 2B provides a side view of a multispectral biometric sensor shown in another embodiment;
FIG. 3 provides a front view of a computer tomographic imaging spectrometer (“CTIS”) in one embodiment of the invention;
FIG. 4 provides a top view of a swipe sensor in an embodiment of the invention;
FIG. 5 illustrates a multispectral datacube generated in accordance with embodiments of the invention;
FIG. 6 is a graphical illustration of the effects of skin scatter;
FIG. 7 provides a graphical illustration of the effects of blood absorbance;
FIG. 8 provides examples of different illumination characteristics that may be used in embodiments of the invention;
FIG. 9A provides a flow diagram illustrating a method for using an alcohol monitor in accordance with an embodiment of the invention;
FIG. 9B provides a flow diagram illustrating a method for using a combination of an alcohol monitor and a biometric sensor with an embodiment of the invention;
FIG. 9C provides a flow diagram illustrating a method for accommodating optical drift in embodiments of the invention; and
FIG. 10 provides a schematic representation of a computer system that may be used to manage functionality of alcohol monitors in accordance with embodiments of the invention.
DETAILED DESCRIPTION OF THE INVENTION
1. Overview
Embodiments of the invention provide methods and systems that allow for the collection and processing of integrated, multifactor biometric measurements. These integrated, multifactor biometric measurements may provide strong assurance of a person's identity, as well as of the authenticity of the biometric sample being taken. In some embodiments, a sensor provides a plurality of discrete optical wavelengths that penetrate the surface of the skin, and scatter within the skin and/or underlying tissue. As used herein, reference to “discrete wavelengths” is intended to refer to sets of wavelengths or wavelength bands that are treated as single binned units—for each binned unit, information is extracted only from the binned unit as a whole, and not from individual wavelength subsets of the binned unit. In some cases, the binned units may be discontinuous so that when a plurality of discrete wavelengths are provided, some wavelength between any pair of the wavelengths or wavelength bands is not provided, but this is not required in all embodiments. In one embodiment, the optical wavelengths are within the ultraviolet—visible—near-infrared wavelength range. A portion of the light scattered by the skin and/or underlying tissue exits the skin and is used to form a multispectral image of the structure of the tissue at and below the surface of the skin. As used herein, the term “multispectral” is intended to be construed broadly as referring to methods and systems that use multiple wavelengths, and thus includes imaging systems that are “hyperspectral” or “ultraspectral” as those terms are understood by those of skill in the art. Because of the wavelength-dependent properties of the skin, the image formed from each wavelength of light is usually different from images formed at other wavelengths. Accordingly, embodiments of the invention collect images from each of the wavelengths of light in such a way that characteristic spectral and spatial information may be extracted by an algorithm applied to the resulting multispectral image data.
In some applications, it may be desirable to estimate other parameters and characteristics of a body, either independently or in combination with a biometric measurement. For example, in one specific such embodiment, an ability is provided to measure blood-alcohol levels of a person simultaneously with measurement of a fingerprint pattern; such an embodiment has applications to law enforcement as well as to a variety of commercial applications including restricting motor-vehicle access. In this way, the analyte measurement and the identity of the person on whom the measurement is made may be inextricably linked.
Skin composition and structure is very distinct, very complex, and varies from person to person. By performing optical measurements of the spatio-spectral properties of skin and underlying tissue, a number of assessments may be made. For example, a biometric-identification function may be performed to identify or verify whose skin is being measured, a liveness function may be performed to assure that the sample being measured is live and viable skin and not another type of material, estimates may be made of a variety of physiological parameters such as age gender, ethnicity, and other demographic and anthropometric characteristics, and/or measurements may be made of the concentrations of various analytes and parameters including alcohol, glucose, degrees of blood perfusion and oxygenation, biliruben, cholesterol, urea, and the like.
The complex structure of skin may be used in different embodiments to tailor aspects of the methods and systems for particular functions. The outermost layer of skin, the epidermis, is supported by the underlying dermis and hypodermis. The epidermis itself may have five identified sublayers that include the stratum corneum, the stratum lucidum, the stratum granulosum, the stratum spinosum, and the stratum germinativum. Thus, for example, the skin below the top-most stratum corneum has some characteristics that relate to the surface topography, as well as some characteristics that change with depth into the skin. While the blood supply to skin exists in the dermal layer, the dermis has protrusions into the epidermis known as “dermal papillae,” which bring the blood supply close to the surface via capillaries. In the volar surfaces of the fingers, this capillary structure follows the structure of the friction ridges on the surface. In other locations on the body, the structure of the capillary bed may be less ordered, but is still characteristic of the particular location and person. As well, the topography of the interface between the different layers of skin is quite complex and characteristic of the skin location and the person. While these sources of subsurface structure of skin and underlying tissue represent a significant noise source for non-imaging optical measurements of skin for biometric determinations or analyte measurements, the structural differences are manifested by spectral features compared through embodiments of the invention.
In some instances, inks, dyes and/or other pigmentation may be present in portions of the skin as topical coating or subsurface tattoos. These forms of artificial pigmentation may or may not be visible to the naked human eye. However, if one or more wavelengths used by the apparatus of the present invention is sensitive to the pigment, the sensor can be used in some embodiments to verify the presence, quantity and/or shape of the pigment in addition to other desired measurement tasks.
In general, embodiments of the present invention relate to methods and systems for collecting spatio-spectral information in the form of multispectral images or datacubes. In certain instances, the desired information is contained in just a portion of the entire multispectral datacube. For example, estimation of a uniformly distributed, spectrally active compound may require just the measure spectral characteristics, which can be extracted from the overall multispectral datacube. In such cases, the overall system design may be simplified to reduce or eliminate the spatial component of the collected data by reducing the number of image pixels, even to a limit of a single pixel. Thus, while the systems and methods disclosed are generally described in the context of multispectral imaging, it will be recognized that the invention encompasses similar measurements in which the degree of imaging is greatly reduced, even to the point where there is a single detector element.
2. Exemplary Embodiments
One embodiment of the invention is depicted with the schematic diagram of FIG. 1 , which shows a front view of a multispectral biometric sensor 101 . The multispectral sensor 101 comprises an illumination subsystem 121 having one or more light sources 103 and a detection subsystem 123 with an imager 115 . The figure depicts an embodiment in which the illumination subsystem 121 comprises a plurality of illumination subsystems 121 a and 121 b , but the invention is not limited by the number of illumination or detection subsystems 121 or 123 . For example, the number of illumination subsystems 121 may conveniently be selected to achieve certain levels of illumination, to meet packaging requirements, and to meet other structural constraints of the multispectral biometric sensor 101 . Illumination light passes from the source 103 through illumination optics 105 that shape the illumination to a desired form, such as in the form of flood light, light lines, light points, and the like. The illumination optics 105 are shown for convenience as consisting of a lens but may more generally include any combination of one or more lenses, one or more mirrors, and/or other optical elements. The illumination optics 105 may also comprise a scanner mechanism (not shown) to scan the illumination light in a specified one-dimensional or two-dimensional pattern. The light source 103 may comprise a point source, a line source, an area source, or may comprise a series of such sources in different embodiments. In one embodiment, the illumination light is provided as polarized light, such as by disposing a linear polarizer 107 through which the light passes before striking a finger 119 or other skin site of the person being studied.
In some instances, the light source 103 may comprise one or more quasimonochromatic sources in which the light is provided over a narrow wavelength band. Such quasimonochromatic sources may include such devices as light-emitting diodes, laser diodes, or quantum-dot lasers. Alternatively, the light source 103 may comprise a broadband source such as in incandescent bulb or glow bar. In the case of a broadband source, the illumination light may pass through a bandpass filter 109 to narrow the spectral width of the illumination light. In one embodiment, the bandpass filter 109 comprises one or more discrete optical bandpass filters. In another embodiment, the bandpass filter 109 comprises a continuously variable filter that moves rotationally or linearly (or with a combination of rotational and linear movement) to change the wavelength of illumination light. In still another embodiment, the bandpass filter 109 comprises a tunable filter element such as a liquid-crystal tunable filter, an acousto-optical tunable filter, a tunable Fabry-Perot filter or other filter mechanism known to one knowledgeable in the art.
After the light from the light source 103 passes through the illumination optics 105 , and optionally the optical filter 109 and/or polarizer 107 , it passes through a platen 117 and illuminates the finger 119 or other skin site. The sensor layout and components may advantageously be selected to minimize the direct reflection of the illumination into the detection optics 113 . In one embodiment, such direct reflections are reduced by relatively orienting the illumination subsystem 121 and detection subsystem 123 such that the amount of directly reflected light detected is minimized. For instance, optical axes of the illumination subsystem 121 and the detection subsystem 123 may be placed at angles such that a mirror placed on the platen 117 does not direct an appreciable amount of illumination light into the detection subsystem 123 . In addition, the optical axes of the illumination and detection subsystems 121 and 123 may be placed at angles relative to the platen 117 such that the angular acceptance of both subsystems is less than the critical angle of the system; such a configuration avoids appreciable effects due to total internal reflectance between the platen 117 and the skin site 119 .
An alternative mechanism for reducing the directly reflected light makes use of optical polarizers. Both linear and circular polarizers can be employed advantageously to make the optical measurement more sensitive to certain skin depths, as known to one familiar in the art. In the embodiment illustrated in FIG. 1 , the illumination light is polarized by linear polarizer 107 . The detection subsystem 123 may then also include a linear polarizer 111 that is arranged with its optical axis substantially orthogonal to the illumination polarizer 107 . In this way, light from the sample must undergo multiple scattering events to significantly change its state of polarization. Such events occur when the light penetrates the surface of the skin and is scattered back to the detection subsystem 123 after many scatter events. In this way, surface reflections at the interface between the platen 117 and the skin site 119 are reduced.
The detection subsystem 123 may incorporate detection optics that comprise lenses, mirrors, and/or other optical elements that form an image of the region near the platen surface 117 onto the detector 115 . The detection optics 113 may also comprise a scanning mechanism (not shown) to relay portions of the platen region onto the detector 115 in sequence. In all cases, the detection subsystem 123 is configured to be sensitive to light that has penetrated the surface of the skin and undergone optical scattering within the skin and/or underlying tissue before exiting the skin.
The illumination subsystem 121 and detection subsystem 123 may be configured to operate in a variety of optical regimes and at a variety of wavelengths. One embodiment uses light sources 103 that emit light substantially in the region of 400-1000 nm; in this case, the detector 115 may be based on silicon detector elements or other detector material known to those of skill in the art as sensitive to light at such wavelengths. In another embodiment, the light sources 103 may emit radiation at wavelengths that include the near-infrared regime of 1.0-2.5 μm, in which case the detector 115 may comprise elements made from InGaAs, InSb, PbS, MCT, and other materials known to those of skill in the art as sensitive to light at such wavelengths.
A side view of one of the embodiments of the invention is shown with the schematic drawing provided in FIG. 2A . For clarity, this view does not show the detection subsystem, but does show an illumination subsystem 121 explicitly. The illumination subsystem 121 in this embodiment includes two discrete light sources 203 and 205 that have different wavelength characteristics. For example, the light sources 203 and 205 may be quasimonochromatic sources such as LEDs, which do not require an optical filter. Sources 203 a , 203 b , and 203 c may provide illumination with substantially the same first wavelength while sources 205 a , 205 b , and 205 c may provide illumination with substantially the same second wavelength, different from the first wavelength. As shown, the illumination optics in FIG. 2A are configured to provide flood illumination, but in alternative embodiments could be arranged to provide line, point, or other patterned illumination by incorporation of cylindrical optics, focusing optics, or other optical components as known to those knowledgeable in the art.
An exemplary measurement sequence for the system shown in FIG. 2A comprising activating the first light sources 203 and collecting a resulting image. After the image is acquired, the first light sources 203 are turned off and the second light sources 205 are activated at a different wavelength, and a resulting image is collected. For a sensor having more than one wavelength of light source, this illumination-measurement sequence is repeated for all the different wavelengths used in the sensor. It will also be appreciated that substantially the same sequence may be used in embodiments in which the wavelength characteristics of light are determined by states of tunable optical filters, variable optical filters, moveable discrete optical filters, and the like. Also, an alternative mechanism for collecting images at multiple wavelengths may incorporate an encoding method to identify light of each wavelength when multiple wavelengths are illuminated at a given time. The data from the entire illumination sequence is then collected in such a way that the individual wavelength responses are determined from the encoding using methods known to those of skill in the art. Illumination techniques thus include round-robin, frequency-division modulation, Hadamard encoding, and others.
The sequence of illumination of the light sources may be changed from measurement to measurement. This variability may be introduced to thwart replay attacks where a set of valid signals is recorded and replayed at a later time to defeat the biometric sensor. The measurement variability from sample to sample may also extend in some embodiments to using only a subset of available illumination wavelengths, which are then compared with the corresponding subset of data in an enrollment dataset.
The array of light sources 203 and 205 need not actually be planar as shown in FIG. 2A . For example, in other embodiments, optical fibers, fiber bundles, or fiber optical faceplates or tapers could convey the light from the light sources at some convenient locations to an illumination plane, where light is reimaged onto the finger. The light sources could be controlled by turning the drive currents on and off as LEDs might be. Alternatively, if an incandescent source is used, rapid switching of the light may be accomplished using some form of spatial light modulator such as a liquid crystal modulator or using microelectromechanical-systems (“MEMS”) technology to control apertures, mirrors, or other such optical elements.
The use of optical components such as optical fibers and fiber bundles may allow the structure of the multispectral biometric sensor to be simplified. One embodiment is illustrated in FIG. 2B , which shows the use of optical fibers and electronic scanning of illumination sources such as LEDs. Individual fibers 216 a connect each of the LEDs located at an illumination array 210 to an imaging surface, and other fibers 216 b relay the reflected light back to the imaging device 212 , which may comprise a photodiode array or CCD array. The set of fibers 216 a and 216 b thus defines an optical fiber bundle 214 used in relaying light.
Another embodiment of the invention is shown schematically with the front view of FIG. 3 . In this embodiment, the multispectral biometric sensor 301 comprises a broadband illumination subsystem 323 and a detection subsystem 325 . As for the embodiment described in connection with FIG. 1 , there may be multiple illumination subsystems 323 in some embodiments, with FIG. 3 showing a specific embodiment having two illumination subsystems 323 . A light source 303 comprised by the illumination subsystem 323 is a broadband illumination source such as an incandescent bulb or a glowbar, or may be any other broadband illumination source known to those of skill in the art. Light from the light source 303 passes through illumination optics 305 and a linear polarizer 307 , and may optionally pass through a bandpass filter 309 used to limit the wavelengths of light over a certain region. The light passes through a platen 117 and into a skin site 119 . A portion of the light is diffusely reflected from the skin 119 into the detection subsystem 325 , which comprises imaging optics 315 and 319 , a crossed linear polarizer 311 , and a dispersive optical element 313 . The dispersive element 313 may comprise a one- or two-dimensional grating, which may be transmissive or reflective, a prism, or any other optical component known in the art to cause a deviation of the path of light as a function of the light's wavelength. In the illustrated embodiment, the first imaging optics 319 acts to collimate light reflected from the skin 119 for transmission through the crossed linear polarizer 311 and dispersive element 313 . Spectral components of the light are angularly separated by the dispersive element 313 and are separately focused by the second imaging optics 315 onto a detector 317 . As discussed in connection with FIG. 1 , the polarizers 307 and 311 respectively comprised by the illumination and detection subsystems 323 and 325 act to reduce the detection of directly reflected light at the detector 317 .
The multispectral image generated from light received at the detector is thus a “coded” image in the manner of a computer tomographic imaging spectrometer (“CTIS”). Both wavelength and spatial information are simultaneously present in the resulting image. The individual spectral patterns may be obtained by mathematical inversion or “reconstruction” of the coded image.
The embodiments described above in connection with FIGS. 1-3 are examples of “area” sensor configurations. In addition to such area sensor configurations, multispectral imaging sensors may be configured as “swipe” sensors in some embodiments. One example of a swipe sensor is shown in top view with the schematic illustration of FIG. 4 . In this figure, the illumination region 403 and detection region 405 of a sensor 401 are substantially collinear. In some embodiments of a swipe sensor 401 , there may be more than a single illumination region. For example, there may be a plurality of illumination regions arranged on either side of the detection region 405 . In some embodiments, the illumination region 403 may partially or fully overlap the detection region 405 . The multispectral image data are collected with the sensor 401 by swiping a finger or other body part across the optically active region, as indicated by the arrow in FIG. 4 . The corresponding linear sensor may be a stationary system or a roller system that may further include an encoder to record the position information and aid in stitching a full two-dimensional image from a resulting series of image slices as known to one knowledgeable in the art. When the roller system is used, a fingertip or other skin site may be rolled over a roller that is transparent to the wavelengths of light used. The light is then sequentially received from discrete portions of the skin site, with the multispectral image being built up from light received from the different portions.
The polarizers included with some embodiments may also be used to create or further accentuate the surface features. For instance, if the illumination light is polarized in a direction parallel (“P”) with the sampling platen and the detection subsystem incorporates a polarizer in a perpendicular orientation (“S”), then the reflected light is blocked by as much as the extinction ratio of the polarizer pair. However, light that crosses into the fingertip at a ridge point is optically scattered, which effectively randomizes the polarization. This allows a portion, on the order of 50%, of the absorbed and re-emitted light to be observed by the S-polarized imaging system.
The systems described in connection with the specific embodiments above are illustrative and are not intended to be limiting. There are numerous variations and alternatives to the exemplary embodiments described above that are also within the intended scope of the invention. In many instances, the layout or order of the optical components may be changed without substantially affecting functional aspects of the invention. For example, in embodiments that use broadband illumination sources and one or more optical filters, the filter(s) may be located at any of a variety of points in both the illumination and detection subsystems. Also, while the figures show the finger or other skin site from which measurements are made being in contact with the platen, it will be evident that substantially the same measurements may be made without such contact. In such instances, the optical systems for illumination and detection may be configured to illuminate and image the skin site at a distance. Some examples of such systems are provided in U.S. Prov. Pat. Appl. No. 60/552,662, entitled “OPTICAL SKIN SENSOR FOR BIOMETRICS,” filed Mar. 10, 2004, which has been incorporated by reference.
The embodiments described above produce a set of images of the skin site at different wavelengths or produce data from which such a set may be produced using reconstruction techniques, such as in the particular case of the CTIS or encoded illumination subsystems. For purposes of illustration, the following discussion is made with reference to such a set of spectral images, although it in not necessary to produce them for subsequent biometric processing in those embodiments that do not generate them directly. An illustrative set of multispectral images is shown in FIG. 5 , with the set defining a multispectral datacube 501 .
One way to decompose the datacube 501 is into images that correspond to each of the wavelengths used in illuminating the sample in the measurement process. In the figure, five separate images 503 , 505 , 507 , 509 , and 511 are shown, corresponding to five discrete illumination wavelengths and/or illumination conditions (e.g. illumination point source at position X, Y). In an embodiment where visible light is used, the images might correspond, for example, to images generated using light at 450 nm, 500 nm, 550 nm, 600 nm, and 650 nm. Each image represents the optical effects of light of a particular wavelength interacting with skin and, in the case of embodiments where the skin is in contact with a platen during measurement, represents the combined optical effects of light of a particular wavelength interacting with skin and also passing through the skin-platen interface. Due to the optical properties of skin and skin components that vary by wavelength, each of the multispectral images 503 , 505 , 507 , 509 , and 511 will be, in general, different from the others
The datacube may thus be expressed as R(X S , Y S , X I , Y I , λ) and describes the amount of diffusely reflected light of wavelength λ seen at each image point X I , Y I when illuminated at a source point X S , Y S . Different illumination configurations (flood, line, etc.) can be summarized by summing the point response over appropriate source point locations. A conventional non-TIR fingerprint image F(X I , Y I ) can loosely be described as the multispectral data cube for a given wavelength, λ o , and summed over all source positions:
F ( X I , Y I ) = ∑ Y S ∑ X S R ( X S , Y S , X I , Y I , λ 0 ) .
Conversely, the spectral biometric dataset S(λ) relates the measured light intensity for a given wavelength λ to the difference {right arrow over (D)} between the illumination and detection locations:
S ( {right arrow over (D)} ,λ)= R ( X I −X S ,Y I −Y S ,λ).
The multispectral datacube R is thus related to both conventional fingerprint images and to spectral biometric datasets. The multispectral datacube R is a superset of either of the other two data sets and contains correlations and other information that may be lost in either of the two separate modalities.
The optical interactions at the skin-platen interface will be substantially the same at all wavelengths since the optical qualities of the platen material and the skin are not generally significantly different over the range of wavelengths used and the optical interface does not change substantially during the measurement interval. Light migrated from the skin to the platen, as well as from the platen to the skin, will be affected by Fresnel reflections at the optical interfaces. Thus, light that traverses an air gap will be less intense in the receiving medium than light that does not cross an air gap. This phenomenon forms just one portion of the image information that is contained in the multispectral datacube.
The light that passes into the skin and/or underlying tissue is generally affected by different optical properties of the skin and/or underlying tissue at different wavelengths. Two optical effects in the skin and/or underlying tissue that are affected differently at different wavelengths are scatter and absorbance. Optical scatter in skin tissue is generally a smooth and relatively slowly varying function of wavelength, as shown in FIG. 6 . Conversely, absorbance in skin is generally a strong function of wavelength due to particular absorbance features of certain components present in the skin. For example, blood has certain characteristic absorbance features as shown in FIG. 7 . In addition to blood, other substances that have significant absorbance properties in the spectral region from 400 nm to 2.5 μm and that are found in skin and/or underlying tissue include melanin, water, carotene, biliruben, ethanol, and glucose.
The combined effect of optical absorbance and scatter causes different illumination wavelengths to penetrate the skin to different depths. This effect is illustrated schematically in FIG. 8 , which depicts the optical scattering that occurs in tissue for three different illumination points on the surface of skin at three different wavelengths, shown with the same scale. This phenomenon effectively causes the different spectral images to have different and complementary information corresponding to different volumes of the illuminated tissue. In particular, the capillary layers close to the surface of the skin have distinct spatial characteristics that can be imaged using wavelengths of light in which blood is strongly absorbing.
Thus, the multispectral image datacube contains spatio-spectral information from multiple sources. Merely by way of example, for the case of a measurement taken on the fingertip in contact with a platen, the resulting datacube contains effects due to: (i) the optical interface between the fingertip and the platen, similar to information contained in a conventional non-TIR fingerprint; (ii) the overall spectral characteristics of the tissue, which are distinct from person to person; (iii) the blood vessels close to the surface of the skin, similar to vein imaging; and (iv) the blood vessels and other spectrally active structures distributed deeper in the tissue. As such, embodiments of the invention provide a mechanism for extracting biometric data from multiple sources within the fingertip or other skin site being measured, thereby providing multifactor biometric-sensing applications.
Because of the complex wavelength-dependent properties of skin and underlying tissue, the set of spectral values corresponding to a given image location has spectral characteristics that are well-defined and distinct. These spectral characteristics may be used to classify the multispectral image data on a pixel-by-pixel basis. This assessment may be performed by generating typical tissue spectral qualities from a set of qualified images. For example, the multispectral data shown in FIG. 5 may be reordered as an N×5 matrix, where N is the number of image pixels that contain data from living tissue, rather than from a surrounding region of air. An eigenanalysis or other factor analysis performed on this set matrix produces the representative spectral features of these tissue pixels. The spectra of pixels in a later data set may then be compared to such previously established spectral features using metrics such as Mahalanobis distance and spectral residuals. If more than a small number of image pixels have spectral qualities that are inconsistent with living tissue, then the sample is deemed to be non-genuine and rejected, thus providing a mechanism for incorporating antispoofing methods in the sensor based on determinations of the liveness of the sample.
Similarly, in an embodiment where the sample is a fingertip, the multispectral image pixels are classified as “ridge,” “valley,” or “other,” based on their spectral qualities. This classification can be performed using discriminant analysis methods such as linear discriminant analysis, quadratic discriminant analysis, principle component analysis, neural networks, and others known to those of skill in the art. Since ridge and valley pixels are contiguous on a typical fingertip, in some instances multispectral data from the local neighborhood around the image pixel of interest are used to classify the image pixel. In this way, a conventional fingerprint image is extracted from the sensor for further processing and biometric assessment. The “other” category may indicate image pixels that have spectral qualities that are different than anticipated in a genuine sample. A threshold on the total number of pixels in an image classified as “other” may be set. If this threshold is exceeded, the sample may be determined to be non-genuine and appropriate indications made and actions taken.
Biometric determinations of identity may be made using the entire datacube or particular portions thereof. For example, appropriate spatial filters may be applied to separate out the lower spatial frequency information that is typically representative of deeper spectrally active structures in the tissue. The fingerprint data may be extracted using similar spatial frequency separation and/or the pixel classification methods disclosed above. The spectral information can be separated from the active portion of the image in the manner discussed above. These three portions of the datacube may then be processed and compared to the corresponding enrollment data using methods known to one familiar with the art to determine the degree of match. Based upon the strength of match of these characteristics, a decision can be made regarding the match of the sample with the enrolled data.
As previously noted, certain substances that may be present in the skin and underlying tissue have distinct absorbance characteristics. For example, ethanol has characteristic absorbance peaks at approximately 2.26 μm, 2.30 μm, and 2.35 μm, and spectral troughs at 2.23 μm, 2.28 μm, 2.32 μm, and 2.38 μm. In some embodiments, noninvasive optical measurements are performed at wavelengths in the range of 2.1-2.5 μm, more particularly in the range of 2.2-2.4 μm. In an embodiment that includes at least one of the peak wavelengths and one of the trough wavelengths, the resulting spectral data are analyzed using multivariate techniques such as partial least squares, principal-component regression, and others known to those of skill in the art, to provide an estimate of the concentration of alcohol in the tissue, as well as to provide a biometric signature of the person being tested. While a correlation to blood-alcohol level may be made with values determined for a subset of these wavelengths, it is preferable to test at least the three spectral peak values, with more accurate results being obtained when the seven spectral peak and trough values are measured.
In other embodiments, noninvasive optical measurements are performed at wavelengths in the range of 1.5-1.9 μm, more particularly in the range of 1.6-1.8 μm. In specific embodiments, optical measurements are performed at one or more wavelengths of approximately 1.67 μm, 1.69 μm, 1.71 μm, 1.73 μm, 1.74 μm 1.76 μm and 1.78 m. The presence of alcohol is characterized at these wavelengths by spectral peaks at 1.69 μm, 1.73 μm, and 1.76 μm and by spectral troughs at 1.67 μm, 1.71 μm, 1.74 μm, and 1.78 μm. Similar to the 2.1-2.5 μm wavelength range, the concentration of alcohol is characterized by relative strengths of one or more of the spectral peak and trough values. Also, while a correlation to blood-alcohol level may be made with values determined for a subset of these wavelengths in the 1.5-1.9 μm range, it is preferable to test at least the three spectral peak values, with more accurate results being obtained when the seven spectral peak and trough values are measured.
A small spectral alcohol-monitoring device may be embedded in a variety of systems and applications in certain embodiments. The spectral alcohol-monitoring device can be configured as a dedicated system such as may be provided to law-enforcement personnel, or may be integrated as part of an electronic device such as an electronic fob, wristwatch, cellular telephone, PDA, or any other electronic device, for an individual's personal use. Such devices may include mechanisms for indicating to an individual whether his blood-alcohol level is within defined limits. For instance, the device may include red and green LEDs, with electronics in the device illuminating the green LED if the individual's blood-alcohol level is within defined limits and illuminating the red LED if it is not. In one embodiment, the alcohol-monitoring device may be included in a motor vehicle, typically positioned so that an individual may conveniently place tissue, such as a fingertip, on the device. While in some instances, the device may function only as an informational guide indicating acceptability to drive, in other instances ignition of the motor vehicle may affirmatively depend on there being a determination that the individual has a blood-alcohol level less than a prescribed level.
This type of action is an example of a more general set of actions that may be performed with the alcohol-monitoring devices of the invention. Such general methods as they may be implemented by the alcohol-monitoring device are summarized in FIG. 9A . At block 902 , an alcohol-level determination is performed with spectral information as described above. At block 904 , a determination is made from the alcohol-level determination whether the alcohol level is within prescribed limits. If it conforms with such limits, a first action is taken at block 906 . This action may correspond, for example, to allowing ignition of a motor vehicle, allowing a pilot to enter an aircraft, allowing an employee to enter a workplace, and the like. If the alcohol-level determination does not conform to the prescribed limits, a second action is taken at block 908 . This action may correspond, for example, to preventing ignition of a motor vehicle, prohibiting access by a pilot to an aircraft or an employee to a workplace, and the like.
In some instances, the blood-alcohol determination may be coupled with a biometric determination. An overview of such combined methods is provided with the flow diagram of FIG. 9B . At block 910 , an alcohol-level determination is performed using spectral information as described above. Different actions may be taken depending on whether the determined alcohol level is within prescribed limits, as tested at block 912 . If the alcohol limit is outside the prescribed limits, a first action may be taken at block 914 , such as prohibiting ignition of a motor vehicle. Access to the motor vehicle might, however, not automatically be granted by the system merely because the alcohol level was within the prescribed limits. As indicated at block 916 , a determination that those limits are met may instead prompt a biometric test to be performed so that a check of an individual's identity is performed at block 918 . If the person is identified as a specific person, such as the owner of the motor vehicle, a second action allowing access to the motor vehicle may be taken at block 920 . If the person identified is not the specific person, a third action may be taken at block 922 . This third action could correspond, for example, to the first action so that access to the motor vehicle is restricted, but could alternatively correspond to an action different from the first or second actions. For example, the third action could result in the sounding of an alarm to indicate that an unknown person is attempting to gain control of a motor vehicle.
The flow diagrams in FIG. 9B provide examples where a biometric test may be used to override a decision that would be made in response to a particular result of an alcohol-monitoring test. In other embodiments, a biometric test could be performed in response to the contrary result for the alcohol-monitoring test, or could be performed irrespective of the result of the alcohol-monitoring test. In such cases, different actions could be taken depending on the various combinations of results of the alcohol-level and biometric determinations. Furthermore, there is no need for the alcohol-monitoring test to precede the biometric determination; the tests could be performed in a different order or simultaneously in different embodiments.
In some embodiments, correction is made for optical drift by determining an optical correction from use of the alcohol-monitoring device on a reference sample. An overview of a method for making such a correction is provided in FIG. 9C . At block 932 , optical sources of the alcohol-monitoring device are used to illuminate the reference sample, which could conveniently comprise an alcohol-water mixture. At block 934 , a detector of the alcohol-monitoring device is used to measure spectral characteristics of light after propagation through the reference sample. These spectral characteristics are usually stored for later application to a variety of different spectral determinations. Thus, at block 936 , the light sources of the alcohol-monitoring device are used to illuminate tissue of an individual and at block 938 , the spectral characteristics of light propagated through the tissue are measured with a detector of the alcohol-monitoring device. Before making a determination of blood-alcohol level using the peak-trough comparison analysis described above, the spectral characteristics are corrected in accordance with the spectral characteristics determined from the reference sample at block 940 . Changes that occur to the light sources, detectors, optical filters, lenses, mirrors, and other components in the optical chain will affect both the in vivo measurement and the reference sample in a similar manner. Processing of the in vivo sample in conjunction with the alcohol-bearing reference sample thus compensates for such optical effects.
Management of the functionality discussed herein for the alcohol-monitoring device may be performed with a computer system. The arrangement shown in FIG. 10 includes a number of components that may be appropriate for a larger system; smaller systems that are integrated with portable devices may use fewer of the components. FIG. 10 broadly illustrates how individual system elements may be implemented in a separated or more integrated manner. The computational device 1000 is shown comprised of hardware elements that are electrically coupled via bus 1026 , which is also coupled with the alcohol-monitoring monitoring device 1055 . The hardware elements include a processor 1002 , an input device 1004 , an output device 1006 , a storage device 1008 , a computer-readable storage media reader 1010 a , a communications system 1014 , a processing acceleration unit 1016 such as a DSP or special-purpose processor, and a memory 1018 . The computer-readable storage media reader 1010 a is further connected to a computer-readable storage medium 1010 b , the combination comprehensively representing remote, local, fixed, and/or removable storage devices plus storage media for temporarily and/or more permanently containing computer-readable information. The communications system 1014 may comprise a wired, wireless, modem, and/or other type of interfacing connection and permits data to be exchanged with external devices.
The computational device 1000 also comprises software elements, shown as being currently located within working memory 1020 , including an operating system 1024 and other code 1022 , such as a program designed to implement methods of the invention. It will be apparent to those skilled in the art that substantial variations may be used in accordance with specific requirements. For example, customized hardware might also be used and/or particular elements might be implemented in hardware, software (including portable software, such as applets), or both. Further, connection to other computing devices such as network input/output devices may be employed
FIG. 10 also indicates that a biometric sensor 1056 may also be coupled electrically via bus 1026 for use in those embodiments that combine the use of the alcohol-monitoring device 1055 with the biometric sensor 1056 . As previously mentioned, the biometric sensor 1056 may also use spectral information in making identifications of individuals, although this is not required. The computational device 1000 may equally well be adapted to coordinate the function of any other type of biometric identification device with the alcohol-monitoring device as described above.
Other analytes in the body may be estimated using similar techniques by ensuring that the multispectral data that are measured by the sensor include characteristic absorbance features of the analyte of interest. Such analyte estimation techniques may be further aided using a method similar to the pixel classification technique described above. In such embodiments, the multispectral image pixels are classified as “ridge” or “valley,” or are classified according to another appropriate classification such as “blood vessel” or “no vessel.” A subset of the multispectral data is the extracted and used for the analyte estimation based on the pixel classification. This procedure reduces the variability of the estimation due to optical and physiological differences across the image plane.
Furthermore, the structural configurations for the sensors described herein may vary to reflect consideration of such facts as the cost and availability of off-the-shelf components, materials, designs, and other issues. Certain configurations may be easier, less expensive, and quicker to build than others, and there may be different considerations that affect prototype and volume productions differently. For all embodiments, the optical geometry should be carefully considered. The region of skin that returns a detectable amount of diffusely reflected light varies considerably as a function of the illumination wavelength. For instance, for visible and very near infrared illumination, the short-wavelength illumination points may be laid out on a denser array than the long-wavelength points. It may be preferable for the embodiments that use swipe configurations to have the timing of the illumination and the image acquisition be sufficient for a relatively quick motion across the optically active region of the sensor. A modulated illumination method may advantageously be used for these types of sensors.
Thus, having described several embodiments, it will be recognized by those of skill in the art that various modifications, alternative constructions, and equivalents may be used without departing from the spirit of the invention. Accordingly, the above description should not be taken as limiting the scope of the invention, which is defined in the following claims. | Methods and systems are provided for biometric sensing. An illumination subsystem provides light at discrete wavelengths to a skin site of an individual. A detection subsystem receives light scattered from the skin site. A computational unit is interfaced with the detection system. The computational unit has instructions for deriving a spatially distributed multispectral image from the received light at the discrete wavelengths. The computational unit also has instructions for comparing the derived multispectral image with a database of multispectral images to identify the individual. | 0 |
FIELD
The proposed solution relates to methods and apparatus for short distance high speed communications, and in particular to methods and apparatus employing light emitting diodes in short distance optical communication links.
BACKGROUND
Communications via optical fiber is mature technology. Electronic signals are converted to light signals and the light signals are coupled to an optical fiber which carries the optical signals over the optical link. At the other end of the optical fiber link a photo detector converts the light signal to an electronic signal completing the connection. The means of converting the electronic signal to an optical signal for example employs laser diodes for long distances at very high speed and light emitting diodes for medium distances at high speed.
The means to couple signals from light emitting diodes and laser diodes to optical fiber is well established in the art. U.S. Pat. No. 5,448,676 describes means to align a light emitting diode to the centre of the fiber, U.S. Pat. No. 5,631,992 stresses the use of a rod lens to couple the light source to the optical fiber, and U.S. patent publication number US 2007/0031089 describes means to couple light in a highly efficient method. U.S. Pat. No. 4,466,696 further describes similar coupling of laser diodes or light emitting diodes to optical fiber for the same means to form a communications link between two points. All these methods require mechanically matching the emission angle of the light emitting source to the acceptance angle of the optical fiber by employing intermediary optical equipment.
An ongoing challenge in coupling light emitting diodes to an optical fiber is the mismatch in the physical dimensions of the light emitting diode and the optical fiber. Nominally a multimode optical fiber has a diameter of 60 to 100 microns. A light emitting diode is at least three times larger, nominally 300 microns. Most of the light is lost unless refractive optics are used to converge the light into the optical fiber. In the case where laser diodes are used, which have a smaller emission angle and a small aperture, the cost of the laser diode and the emission angle pose the same problem as with a light emitting diode.
Light emitting diodes, though far lower in cost and suited for medium distances, are still not considered for short distances. This is due to cost constraints. Communications over long and medium distances can carry vast amounts of data at very high speed and the cost is easily amortized over the traffic. At short distances, the amount of data is much less and has to be amortized usually over a single user. One example of this short distance communications problem is referred to as the “last mile problem”. It is feasible to bring optical fiber to a common point in a community and this is common practice. From this common point, connecting to each user via an optical cable link is prohibitive and limits the bandwidth which can be provided to each user. This “last mile” link is presently connected via copper conductors which have limited bandwidth.
There is a need for means of coupling light emitting diodes to an optical fiber, namely without the use of any secondary devices such as refractive optics and mechanical holding devices.
SUMMARY
The invention disclosed provides means to communicate at short distances at high speed via fiber optics making it practical to replace standard copper conductors with optical fiber. This can be a solution to the last mile problem in internet high speed communications.
The disclosure herein is particularly effective in providing means to establish short term communications at very low cost in comparison to prior art methods using large die light emitting diodes or laser diodes.
Micro light emitting diodes, which are substantially smaller than the diameter of multimode optical fiber, when bonded to one end of an optical fiber provide a coupler to couple light (signals) to an optical fiber for means of, namely for the purposes of, illumination or communication without the requirement of using a refractive element to bridge the mismatch between the emission angle of the light source to the acceptance angle of the optical fiber.
In accordance with one aspect of the proposed solution there is provided a coupler for an optical fiber (namely an optical fiber core) with its cladding with a micro light emitting diode placed at the surface of one end of the fiber. The light emitting diode is mounted on a substrate with contact pads with a conductor attached. The two conductors are for providing connections to the drive electronics that would then provide the electronic means of controlling the light emitting diode.
In another aspect of the proposed solution, there is provided a coupler for short distance high speed communications, the coupler comprising: an opening for receiving and securing an end of an optical fiber cable link, said opening defining a longitudinal axis of said coupler, said optical fiber having a diameter; a micro LED die having an emitter area substantially collinear with said longitudinal axis.
In accordance with another aspect of the proposed solution there is provided an optical link for short distance high speed communications comprising: at least one optical coupler; and an optical fiber having at least one end cleaved perpendicular to said axis, said end being inserted in said opening of said coupler, wherein said micro LED abuts a core of said optical fiber, said LED emitting area being having a diameter at least two times smaller than a diameter of a core of the optical fiber.
In accordance with a further aspect of the proposed solution there is provided a telecommunications network comprising a local signal distribution point and a plurality of optical links extending between said signal distribution point and a plurality of subscriber premises.
In accordance with a further aspect of the proposed solution there is provided a micro light emitting diode (LED) mounting assembly for short distance high speed communications over an optical fiber having a diameter, the assembly comprising: a substrate having a obverse face and a reverse face; and a micro LED die mounted on said obverse face, said LED having an emitting area less than three times smaller in diameter than the optical fiber diameter, wherein contact pads are provided on said reverse face for connection to conductors for driving said micro LED.
In accordance with yet another aspect of the proposed solution there is provided a short distance communications system for conveying at least one of signaling and data between a first and a second node, the system comprising: a first micro Light Emitting Diode (LED) assembly at said first node; an optical fiber between said first and said second node, said optical fiber having a first and a second end, each optical fiber end having a core area; and a second micro LED assembly at said second node, each said micro LED assembly having a corresponding micro LED having an emitter area, each micro LED assembly being mounted with corresponding micro LED emitter area orthogonal and abutting said corresponding end of said optical fiber, wherein said emitter are is at least three times smaller than said core area.
BRIEF DESCRIPTION OF DRAWINGS
The invention will be better understood by way of the following detailed description of embodiments of the invention with reference to the appended drawings, in which:
FIG. 1 is a schematic diagram illustrating butt coupling between a micro light emitting diode and an optical fiber in accordance with the proposed solution;
FIG. 2 is a schematic diagram illustrating total internal reflection within the acceptance angle of an optical fiber in accordance with the proposed solution;
FIG. 3 is a schematic diagram illustrating a front view of a printed circuit board assembly in accordance with the proposed solution;
FIG. 4 is another schematic diagram illustrating a back view of the printed circuit board assembly in accordance the proposed solution;
FIG. 5A is a schematic diagram illustrating a socket coupled to an optical fiber in accordance with an embodiment of the proposed solution;
FIG. 5B is a schematic diagram illustrating a carrier for coupling a number of optical fibers in accordance with the embodiment of the proposed solution;
FIG. 5C is a schematic diagram illustrating a “last mile” proposed solution;
FIG. 6 is a schematic diagram illustrating a spectral intensity variation plot for two sub-channels in accordance with the embodiment of the proposed solution;
FIG. 7 is a schematic diagram illustrating an upstream frequency filter pattern in accordance with the embodiment of the proposed solution; and
FIG. 8 is a schematic diagram illustrating a downstream frequency filter pattern in accordance with the embodiment of the proposed solution,
wherein similar features bear similar labels throughout the drawings. Reference to qualifiers such as “top” and “bottom” in the present specification is made solely with reference to the orientation of the drawings as presented in the application and do not imply any absolute spatial orientation.
DETAILED DESCRIPTION
Recent advances in light emitting diode technology has made it possible to fabricate light emitting diode devices as small as a few microns in diameter and a few hundred microns or less from the surface. Such devices, known as micro LEDs, provide the means to couple a light source to an optical fiber directly, namely to provide optical signal coupling as illustrated in FIG. 1 . Furthermore such devices can be fabricated with an integrated concave mirror or a micro lens providing an angle of emission that is narrower than that of standard light emitting diodes. FIG. 1 illustrates a multimode optical fiber 100 with its cladding 102 and a micro LED 200 placed at a cleaved surface 104 of one end of the optical fiber 100 . Typically the optical fiber core 100 nominally has a 60 micron diameter whereas the micro LED 200 nominally has a 20 micron aperture. In the illustrated implementation, the micro LED 200 is mounted on a PCB carrier 300 substrate with contact pads 302 and illustrated with conductors 304 attached. The two conductors 304 illustrated are for providing connections to drive electronics (not shown) that would then provide electronic control of the micro LED 200 . PCB carrier 300 substrate need not be circular.
Properties of such micro LED devices 200 lend themselves as means of providing light at an angle that is close to the acceptance angle of the optical fiber. Namely, such micro LED devices 200 lend themselves to emanating light at an angle 202 that is close to the acceptance angle of the optical fiber 100 as illustrated in FIG. 2 . Light which enters the optical fiber 100 from such a small source ( 200 ) will expand at the angle of emission 202 which is lower than the angle of acceptance of the fiber 100 ensuring a highly efficient optical signal coupling.
In accordance with an embodiment of the proposed solution there is provided an assembly 400 ( FIGS. 3 and 4 ) for mounting a micro LED 200 to an orthogonally cleaved surface 104 of an optical fiber 100 as illustrated in FIG. 1 . A micro LED 200 smaller by three or more factors than an optical fiber 100 diameter allows butt coupling of the micro LED 200 to the optical fiber 100 without the need for optical and mechanical intermediary components. The diameter of the light emitting diode 200 is 20 microns. The diameter of the multimode optical fiber core 100 is 60 microns. For certainty, these dimensions are examples only and the principle is that the light source is many factors smaller than the optical fiber diameter.
The light signal emitted from the micro LED 200 enters the orthogonally cleaved surface 104 without any hindrance or without passing through any other optical device. The light expands internally in the optical fiber 100 and a substantial portion of the light travels longitudinally, as illustrated in FIG. 2 , through the optical fiber 100 to the opposite end of the optical fiber 100 where a photo detector 212 receives the light signal and converts the same to an electrical signal.
In accordance with a preferred implementation of the proposed solution, the mounting assembly 400 includes a micro LED die 204 , without limiting the invention made of GaAs, mounted on the small (PCB) substrate 300 with a driver and impedance matching components 500 preferably on the rear of the substrate 300 opposite the micro LED die 204 . The conductors 304 are attached to the mounting assembly 400 to connect to an external signal. In another implementation the micro LED substrate 204 would also include driver electronics ( 500 ) such that only an external digital signal is required to modulate and drive the micro LED 200 .
For practical purposes in the field where it would not be possible to attach the micro LED 204 , being very small, to the optical fiber 100 , it is preferable to provide the micro LED assembly 400 mounted in a socket 600 (or carrier). As illustrated in FIG. 5 (not to scale) the socket 600 includes a seat 602 for the micro LED assembly 400 and an opening 604 to insert a pre-cleaved optical fiber 100 substantially collinear with the micro LED 204 . The insertion is limited by an appropriate spacer 410 . The material used to make socket 600 has the property of being flexible to accommodate variation in the optical fiber jacket 106 diameter while having sufficient strength to maintain the integrity of the coupling. After inserting the optical fiber 100 in the opening it is envisioned that a fast curing epoxy 606 can be used to secure the coupling.
In accordance with another implementation of the proposed solution a number of micro LED assemblies 400 are mounted in a carrier 600 as illustrated in FIG. 5B . Such a multi assembly carrier 600 is particularly adapted for a signal distribution point in a neighborhood as illustrated in FIG. 5C .
The number of conductors 304 is determined by the functions of the PCB substrate, having for example simplex or duplex transmission capabilities.
Optical fiber communications standards have been established for operation at 1300 nm with the wavelength band extending from 1260 to 1360 nm ( FIG. 6 ).
Today's technology allows design of light emitting diodes whose emission is sufficiently narrow so that two different wavelength sub-bands can be accommodated within the standards band as illustrated in FIG. 6 . In accordance with an implementation of the proposed solution, one micro LED is constructed to be centered at w 1 =1280 nm and the other at w 2 =1320 nm for upstream and downstream signaling sub-channels. The invention is not limited to a particular association of sub-channels to upstream or downstream signaling nor limited to a particular communications channel wavelength.
In accordance with the proposed solution a GaAs device can be constructed where the central area is a light emitter 210 (micro LED) and the surrounding annular area is a photo detector 212 (photodiode). If the emission area 210 has diameter d, the emission area is π(d/2) 2 . If the diameter of the photo detector 212 is D, the area of the photo detector 212 is π((D/2) 2 −(d/2) 2 ). For d=20 microns and D=100 microns, the area of the detector 212 is 24 times larger than that of the emitter 210 . This reduces the need amplification required for detecting the attenuated signal coming in from the opposite end of the optical fiber 100 .
In accordance with a preferred implementation, to make the photo detectors 212 react to only the optical signal coming from the opposite end of the optical fiber 100 , each detector 212 can employ a notch filter to reject signals from the emitter 210 that the detector 212 is part of. With reference to FIG. 7 the emitter 210 emitting w 1 will have a notch filter for w 2 on the detector 212 and with reference to FIG. 8 the emitter 210 emitting at w 2 will have a notch filter at w 1 over the corresponding surrounding detector 212 . The notch filter can include a film or a layer. Color coding can be employed to differentiate between the two assemblies 400 containing the two devices.
Alternatively the means disclosed herein, namely the apparatus disclosed herein, also enables short distance communications for command and control for systems such as automobiles and aircraft as well as any simple or complex organization of subsystems that require fast exchange of information.
While the invention has been shown and described with referenced to preferred embodiments thereof, it will be recognized by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. | The method disclosed provides communication over short distances at high speed via fiber optics making it practical to replace standard copper conductors with optical fiber. This is a solution to the “last mile” problem in Internet high speed communications. | 7 |
FIELD OF THE INVENTION
The present invention relates to splash pads for dissipating kinetic energy of water being discharged from a downspout.
BACKGROUND OF THE INVENTION
Downspout splash pads have been used for years on residential, commercial and industrial buildings in an effort to kill the impact and energy of water exiting from a vertical outlet such as downspout. Usually made of pre-cast concrete or other composite material, conventional splash pads commonly come in two sizes, one for residential uses and the other, typically slightly larger, for commercial and industrial buildings. One of the principal drawbacks to conventional splash pads is that their designs do not take into account the volume of water that will impact and pass over them. Conventional splash pads may kill the impact energy immediately below the downspout opening, but they do nothing to stop the erosion of soil just downhill of the splash pads caused by large volumes of water discharged by the downspout.
Soil erosion is a serious problem especially in the case of buildings with large roof expanses. Indeed, the problem is so pronounced that in order to curtail erosion in and around buildings with large roof expanses, designers of industrial buildings have opted for underground drainage systems to intercept the runoff and convey the runoff to other pipes that eventually discharge to a ditch outfall. This approach to solving the soil erosion problem is very expensive.
Therefore, there is and continues to be a need for a splash pad that not only dissipates the energy of the falling water, but also acts to control soil erosion downstream or downhill from the splash pad.
SUMMARY OF THE INVENTION
The present invention comprises a splash pad for receiving water from a downspout associated with a building and controlling the velocity and discharge flow rate of water from the splash pad. The splash pad includes a surrounding sidewall structure that defines a water receiving area. An aggregate such as riprap can be disposed within the splash pad for dissipating kinetic energy of water directed from the downspout into the splash pad. Formed about the splash pad is a spillway that permits water accumulated in the splash pad to be discharged.
Further, the present invention entails a method of controlling erosion resulting from water from a roof structure being discharged through a downspout. The method entails directing water from the roof structure to a downspout and from the downspout onto an aggregate, such as riprap, contained within a splash pad having a surrounding wall structure and a bottom formed by a structure or even the ground. Water received by the splash pad is confined therein by the surrounding wall structure. Accumulated water is directed from the splash pad through a spillway formed on the splash pad.
Other objects and advantages of the present invention will become apparent and obvious from a study of the following description and the accompanying drawings, which are merely illustrative of such invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the splash pad of the present invention.
FIG. 2 is a cross sectional view of the splash pad shown in FIG. 1 .
FIG. 3 is a cross sectional view of an alternative splash pad.
FIG. 4 is a top elevational view of yet another alternative splash pad.
FIG. 5 is a side elevational view of the splash pad shown in FIG. 4 .
FIG. 6 is a cross sectional view of the splash pad shown in FIG. 4 .
DESCRIPTION OF EXEMPLARY EMBODIMENTS
With further reference to the drawings, the splash pad of the present invention are shown therein and indicated generally by the numeral 10 . As will be appreciated from subsequent portions of this disclosure, splash pad 10 is designed to be located or positioned adjacent a building 50 having a downspout 60 extending downwardly along a corner or side portion of the building 50 . Downspout 60 is aligned with a splash pad 10 such that water discharged by the downspout will be directed into the splash pad 10 .
Splash pad 10 includes a surrounding sidewall structure 12 . Extending between the sidewall structure 12 is a bottom 14 . Bottom 14 may be structured such as in the case where the splash pad 10 is constructed of plastic or metal. Alternatively, the bottom 14 can simply be a mud slab. Bottom 14 may be particularly sloped. That is, the central portion of the bottom 14 may be slightly raised such that the bottom as a whole slopes downwardly towards the surrounding sidewall structure 12 . A series of weep holes 16 can be provided in the sidewall structure 12 . Weep holes 16 would be placed at an elevation such that residual water contained within the splash pad 10 could drain therefrom. It is contemplated that the splash pad 10 would be made watertight uphill from the splash pad 10 . That means, of course, the splash pad 10 would be particularly designed and/or oriented such that the weep holes 16 , when the splash pad is installed, would be directed downhill.
Further, the splash pad 10 would include an aggregate such as riprap. The aggregate would be disposed on the bottom and would extend upwardly within the splash pad 10 a selected distance. By placing the aggregate or rip rap in the splash pad, the energy associated with the water exiting the downspout 60 is dissipated.
A spillway 12 A is formed around an exterior portion of the splash pad 10 . In the case of the design shown in FIGS. 1–3 , the spillway 12 A is formed along an upper edge of the surrounding sidewall structure 12 . As water accumulates in the splash pad 10 , it will rise to the level of the spillway 12 A and then spill over and exit from the splash pad. It is appreciated that a section of the surrounding sidewall structure can be indented such that only a segment of the surrounding sidewall structure will form the spillway 12 A. This permits selective diversion of the water from the splash pad.
Disposed just outside of the spillway 12 A is a lip 18 . See FIGS. 2 and 3 . Lip 18 will dissipate the kinetic energy associated with the water falling from the spillway. Thus, as seen in the drawings, as the water exits the splash pad 10 , the water will move over the spillway 12 A and fall onto and impact against the lower disposed lip 18 .
Splash pad 10 of the design shown in FIGS. 1–3 , can be constructed of various materials including concrete, plastic or metal. Further, splash pad 10 can assume various shapes. For example, splash pad 10 may be in the form of a quarter-round, half-round, three-quarter, or even a full circle. Additionally, splash pad 10 can be square, rectangular or even other odd or irregular shapes.
Shown in FIGS. 4–6 is another embodiment of the splash pad 10 of the present invention. This splash pad design includes an inner cell indicated generally by the numeral 30 . Inner cell 30 is a depression formed in the splash pad and formed by a bottom 34 and surrounding wall structure 32 . Inner cell 30 is designed to receive and hold aggregate such as riprap. As with the embodiment illustrated in FIGS. 1–3 , this embodiment may also be provided with weep holes formed in the wall structure 32 adjacent the bottom 34 . Thus, residual water remaining in the inner cell 30 can be drained therefrom via the weep holes, preventing mosquito breeding.
Formed on the splash pad 10 adjacent the inner cell 30 is a pair of pad areas or surface areas 36 . In this particular design there is provided a pad area 36 on each side of the inner cell. Pad area 36 is elevated with respect to the bottom 34 of the inner cell 30 .
Surrounding at least a portion of the splash pad 10 is a sidewall or retaining wall 38 . In the case of the particular design shown in FIGS. 4–6 , the retaining wall 38 includes a back and a pair of sides. Formed between the opposed sides that make up the retaining wall 38 is a spillway 40 . Spillway 40 is disposed at an elevation below the upper edge of the retaining wall 38 and, in one embodiment, about at an elevation generally equal to the elevation of the pad area 36 . Water that moves over the pad areas 36 will be dispersed from the splash pad 10 by the spillway 40 . Disposed below the spillway 40 is a lip 42 . Lip 42 dissipates the kinetic energy of water passing from the inner cell 30 and pad areas 36 over the spillway 40 . It is appreciated that as water is directed from a downspout 60 into the inner cell 30 that water will accumulate therein and once the inner cell is filled, it follows that water therefrom will spill over or move onto the pad areas 36 . From the pad areas 36 , the water, because of the retaining wall 38 , will be forced to move over the spillway 40 , falling onto the lip 42 .
In the case of the embodiment or design shown in FIGS. 4–6 , the splash pad 10 is situated underneath a downspout 60 such that the downspout is aligned with the inner cell 30 . Hence, water being discharged from downspout 60 is directed into the inner cell 30 . The aggregate or riprap contained within the inner cell will break or dissipate the kinetic energy associated with the falling water. In the case of the splash pad 10 shown in FIGS. 4–6 , the spillway is situated or aligned in the downhill direction. Hence, water discharged from the splash pad 10 will be directed in the downhill or downgrade direction. It is appreciated that the retaining wall 38 and the spillway 40 can be designed for particular applications to take into account the basic topography or configuration of the ground in and around a building where a downspout exists.
The splash pad 10 , for either design discussed herein, can be constructed in various sizes. For example, the splash pad 10 can be manufactured in standard sizes to cover modular roof areas. For example, a 6′ radius or 3′ by 12′ wide splash pad will accommodate runoff in coastal North Carolina areas with a tributary roof area of 20′×200′ releasing across the top of the splash pad spillway approximately ⅓ gallon of water per second per foot of spillway length.
As noted above, the splash pads 10 can be constructed of various materials including concrete, metal, plastic, fiberglass or other similar non-biodegradable, resilient materials. Splash pads 10 can be installed on level ground. Typically an area underneath a downspout is dug out and the splash pad 10 is installed and leveled. Thereafter, the splash pad is backfilled, either partially or wholly with stone, with average sizes of 3″ to 6″ in diameter.
As discussed above, the aggregate used in the splash pads may be riprap or other insoluble materials. Also, the aggregate may include high-carbon ash, which could possibly remove nitrogen and phosphorous as well as other contaminants from water discharged into the splash pads.
The principal advantage of the splash pad 10 of the present invention is that it curtails or at least minimizes erosion from water being discharged from downspouts associated with buildings with relatively large roof structures. The splash pad 10 of the present invention is designed to remove or dissipate the kinetic energy associated with the falling water and hence distribute the water from the splash pad in a gentle fashion such that the water does not erode soil as it moves from the building to lower elevations.
The present invention may, of course, be carried out in other specific ways than those herein set forth without departing from the scope and the essential characteristics of the invention. The present embodiments are therefore to be construed in all aspects as illustrative and not restrictive and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein. | A splash pad is provided for receiving water directed from a roof structure down a downspout. The splash pad includes a bottom and a surrounding wall structure. A spillway is provided that permits accumulated water in the splash pad to spillover and be discharged from the splash pad. An aggregate such as riprap can be contained within the splash pad for dissipating the kinetic energy of water discharge by the downspout. In addition, a lip can be provided outwardly of the spillway for dissipating the kinetic energy of the water spilling from the splash pad. | 4 |
[0001] This claims the benefit of German Patent Application DE 10 2010 002 214.4 filed Feb. 23, 2010 and hereby incorporated by reference herein.
[0002] The present invention relates to a reinforcement and/or anchor bolt, to a method for reinforcing and/or anchoring bedrock in mining and/or tunnel construction, and to the use of a reinforcement and/or anchor bolt in mining and/or tunnel construction.
BACKGROUND
[0003] Anchor systems are used in mining and tunnel construction to prevent ground movement of the bedrock or to slow it down or to secure large spalls of the bedrock so as to allow safe operation. Here, two functional principles are known which are, at times, also combined with each other. In mechanical systems, the anchor is secured by frictional engagement, whereby mechanical rock anchors generally also have an expansion shell. In chemical systems, reinforcement rods with a curing mortar are connected to the substrate or bedrock by means of adhesion. Here, the anchors are installed with or without pre-tensioning in the bedrock. The drawbacks of these two different anchor systems are that chemical anchor systems are expensive and that, with so-called expansion anchors, a punctual load is applied into the bedrock. Moreover, with chemical anchor systems, the curing is temperature-dependent, so that a long curing time has to be expected at low temperatures. The anchors cannot be dismantled, which is especially disadvantageous when they are used in coal mining.
[0004] European patent application EP 0 623 759 B1 describes a thread-forming bolt that can be screwed directly into concrete masonry or the like and that comprises a bolt head, a bolt shaft and a thread.
[0005] U.S. Pat. No. 5,114,278 discloses a mining bolt with a thread and a conical tip.
SUMMARY OF THE INVENTION
[0006] It is an object of the present invention is to provide a reinforcement and/or anchor bolt, a method for reinforcing and/or anchoring bedrock in mining and/or tunnel construction, and the use of a reinforcement and/or anchor bolt in mining and/or tunnel construction, whereby the reinforcement and/or anchor bolt can be attached inexpensively and reliably to the bedrock with little technical effort.
[0007] The present invention provides a reinforcement and/or anchor bolt that can be used in mining and/or tunnel construction and that can be screwed into bedrock, comprising a bolt head, a bolt end, a bolt shaft and a thread that is at least partially configured on the bolt shaft, whereby the ratio of the length of the reinforcement and/or anchor bolt to the outer diameter of the reinforcement and/or anchor bolt is greater than 20, 30, 50 or 70.
[0008] In particular, the ratio of the of the length of the reinforcement and/or anchor bolt to the outer diameter of the reinforcement and/or anchor bolt may be between 20 and 150, preferably between 30 and 120, especially between 40 and 100.
[0009] In another embodiment, the pitch of the thread corresponds to the product of the outer diameter of the reinforcement and/or anchor bolt and of a factor between 0.2 and 1.2, especially between 0.4 and 0.9.
[0010] In another embodiment, between the bolt head and the bolt end, the thread is configured on the bolt shaft only in the area of the bolt end of the bolt shaft, in particular, the thread is configured on the bolt end only at a distance from the bolt end of less than 80%, 70% or 50% of the length of the reinforcement and/or anchor bolt, and preferably, the core diameter of the bolt shaft without the thread in the area of the bolt head is smaller, preferably by less than 15%, 10%, 5% or 2%, than the core diameter of the bolt shaft with the thread in the area of the bolt end.
[0011] Preferably, the ratio of the outer diameter to the core diameter is between 0.8 and 1.6, preferably between 1.0 and 1.4, especially between 1.1 and 1.2, and/or the ratio of the outer diameter to the pitch of the thread is between 1.0 and 3.0, preferably between 1.5 and 2.5, especially between 1.7 and 2.2, and/or the flank angle is in the range from 50° to 90°. The above-mentioned geometric configuration of the reinforcement and/or anchor bolt allows a reliable positive connection between the reinforcement and/or anchor bolt and the bedrock, especially between the thread of the reinforcement and/or anchor bolt and the bedrock. In this manner, the reinforcement and/or anchor bolt can be reliably connected with a positive fit to the bedrock simply by being screwed into a bore hole in the bedrock. Thus, in an advantageous manner, no chemical systems, for example, curing mortar, are needed to attach the reinforcement and/or anchor bolt to the bedrock, and furthermore, essentially no frictional connection is needed between the reinforcement and/or anchor bolt and the bedrock either, because the reinforcement and/or anchor bolt is attached to the bedrock essentially by means of a positive connection.
[0012] In one variant, the bolt end is configured as a conical tip. The conical tip can be partially or completely shaped onto the bolt end of the reinforcement and/or anchor bolt.
[0013] Advantageously, the bolt end, especially the conical tip, is made at least partially, especially completely, of a material—e.g. metal, especially tempered steel, for example, also as a coating, e.g. made of quartz sand or corundum, or in the form of a ceramic coating—that differs from that of the rest of the reinforcement and/or anchor bolt aside from the bolt end.
[0014] In coal mining (underground mining), so-called longwall mining methods are used more and more often. In this case, the coal seam is mined between longwall panels using a large milling head or plow over the entire length. Before the mining can begin, the panels to be mined have to be secured with the reinforcement and/or anchor bolts, as a result of which the reinforcement and/or anchor bolt is situated in the coal seam that is to be mined. The milling head pulls out the reinforcement and/or anchor bolt together with the coal. Reinforcement and/or anchor bolts made of steel can cause problems when the coal is being conveyed and processed. For this reason, when reinforcement and/or anchor bolts are used in coal mining, they are made, preferably at least partially, of plastic, especially of fiber-reinforced plastic, so that the reinforcement and/or anchor bolt is chopped up by the milling head and cannot damage the conveyor belts. However, in order for the reinforcement and/or anchor bolt to be nevertheless screwed into the bedrock, the bolt end, especially in a configuration as a conical tip, is made of a material that is different from that of the rest of the reinforcement and/or anchor bolt, which is made of plastic. Consequently, the bolt end, especially the conical tip, is made of metal or by means of a coating on the plastic. Moreover, the thread can also be configured as a cutting profile consisting of a hard, wear-resistant layer, for example, the same coating as that on the bolt end.
[0015] In another embodiment, the air-side bolt head is connected, for example, with a positive fit, to the rest of the bolt shaft, and it is made of a material that is different from that of the rest of the bolt shaft. For instance, the bolt head is made of metal, especially steel, and the rest of the bolt shaft is made of plastic. Here, the air-side bolt head preferably has a special geometry, e.g. a hexagonal shape, so that the torque needed to screw in the reinforcement and/or anchor bolt can be applied to the bolt head.
[0016] In an additional embodiment, the diameter of the bolt head is essentially the same size as the core diameter of the bolt shaft or else larger, e.g. by 10%, 20% or 50%, than the core diameter of the bolt shaft.
[0017] In another variant, a thread is present on the bolt head, and a nut, especially an anchor nut, is screwed onto this thread on the bolt head, so that this nut allows the reinforcement and/or anchor bolt to be screwed in as well as tightened, and the force on the anchor head can be transmitted to a head plate or to an anchor head construction.
[0018] Advantageously, the reinforcement and/or anchor bolt, especially aside from the bolt end, can be made at least partially of metal, e.g. steel, or preferably fiber-reinforced plastic, e.g. GFP. Particularly when the reinforcement and/or anchor bolt is used in coal mining, it is made at least partially of plastic.
[0019] In another embodiment, the bolt shaft has a solid or hollow cross section. Particularly in bedrock having a low compressive strength, the bolt shaft can be made with a hollow cross section.
[0020] The invention also relates to a method for reinforcing and/or anchoring bedrock in mining and/or tunnel construction in that a reinforcement and/or anchor bolt, especially a reinforcement and/or anchor bolt described in this patent application, is inserted into the bedrock, whereby a bore hole is drilled into the bedrock and subsequently, the reinforcement and/or anchor bolt is screwed into the bore hole, so that preferably the bedrock is reinforced, and/or preferably an anchor is attached to the bedrock.
[0021] In another embodiment, the thread of the reinforcement and/or anchor bolt cuts its way into the bedrock when the reinforcement and/or anchor bolt is screwed in, and/or a positive connection is created between the thread and the bedrock, and/or a bore hole is drilled whose diameter is smaller, especially by at least 10%, 20% or 30%, than the outer diameter of the reinforcement and/or anchor bolt, and/or a bore hole having a constant diameter is drilled and/or a reinforcement and/or anchor bolt is provided so that the pitch of the thread of the reinforcement and/or anchor bolt is between 0.3 and 1.5, preferably between 0.4 and 1.2, especially between 0.5 and 0.8, times the diameter of the bore hole, and/or a bore hole is drilled and/or a reinforcement and/or anchor bolt is provided so that the core diameter of the thread is smaller, especially by less than 15%, 12% or 8%, than the diameter of the bore hole, and/or a reinforcement and/or anchor bolt is provided so that the flank angle of the reinforcement and/or anchor bolt is calculated according to the formula ((compressive strength of the rock—145)/−1.5)±10° when the compressive strength of the bedrock is between 10 and 100 mPa, and the flank angle is 30°±10° when the compressive strength of the bedrock is more than 100 mPa.
[0022] In another embodiment, a positive connection is created, especially by means of the thread, between the reinforcement and/or anchor bolt and the bedrock, and preferably the amount of the positive connection is at least 50%, 70%, 80% or 90% of the connection of the reinforcement and/or anchor bolt to the bedrock. Hence, the forces to be absorbed by the reinforcement and/or anchor bolt are transferred essentially positively into the bedrock and not by adhesion, by adhesive force or non-positively.
[0023] In particular, the bore hole is drilled with a varying diameter so that an inner section of the bore hole has a diameter that is smaller, preferably by less than 2%, 5%, 10% or 20%, than the diameter in an outer bore hole section.
[0024] In another embodiment, after the reinforcement and/or anchor bolt has been screwed completely into the bore hole, its bolt shaft that is provided with the thread is situated essentially in the inner bore hole section and its bolt shaft without the thread is situated in the outer bore hole section.
[0025] In another variant, after the reinforcement and/or anchor bolt has been screwed completely into the bore hole, the ratio of the anchoring depth of the reinforcement and/or anchor bolt to the diameter of the bore hole is between 20 and 150, preferably between 30 and 120, especially between 40 and 100.
[0026] The invention also relates to the use of a reinforcement and/or anchor bolt in mining and/or tunnel construction for reinforcing bedrock and/or for anchoring, whereby a reinforcement and/or anchor bolt described in this patent application is used.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Below, embodiments of the invention will be described in greater depth with reference to the accompanying drawings. The following is shown:
[0028] FIG. 1 a side view of a reinforcement and/or anchor bolt with a partial lengthwise section of a bore hole in bedrock,
[0029] FIG. 2 a lengthwise section of the reinforcement and/or anchor bolt in the bore hole in a first embodiment,
[0030] FIG. 3 a lengthwise section of the reinforcement and/or anchor bolt in the bore hole in a second embodiment,
[0031] FIG. 4 a lengthwise section of the reinforcement and/or anchor bolt in the bore hole in a third embodiment, and
[0032] FIG. 5 a perspective view of a drill rod.
DETAILED DESCRIPTION
[0033] FIG. 1 shows a reinforcement and/or anchor bolt 1 for use in mining and/or tunnel construction. When used as a reinforcement bolt, bolt 1 serves essentially for reinforcing and stabilizing the bedrock 7 , and thus less for absorbing forces that are applied to the reinforcement bolt 1 on the air-side bolt head 2 and that are especially directed towards a longitudinal axis of the reinforcement bolt 1 . When used as an anchor bolt, bolt 1 serves less for reinforcing and stabilizing the bedrock 7 , but essentially for absorbing forces on the air-side bolt head 2 of the anchor bolt 1 . The reinforcement and/or anchor bolt 1 shown in FIG. 1 can be used as a reinforcement bolt 1 and also as an anchor bolt 1 in mining or tunnel construction.
[0034] The reinforcement and/or anchor bolt 1 ( FIGS. 1 through 4 ) has the air-side bolt head 2 , a bolt end 3 that is arranged in a bore hole 6 ( FIGS. 2 through 4 ), and a thread 5 on a bolt shaft 4 . The bolt shaft 4 has a section that is configured without the thread 5 in the area of the bolt head 2 as a bolt shaft 18 without the thread 5 , and it has a section on the bolt end 3 that is configured as a bolt shaft 19 with a thread 5 . Here, the bolt end 3 is partially configured as a conical tip 9 ( FIG. 1 ). The bolt shaft 4 of the reinforcement and/or anchor bolt 1 has a core diameter D i on the bolt shaft 18 without the thread 5 as well as on the bolt shaft 19 with the thread 5 , and it has an outer diameter D a on the thread 5 and a length A. Furthermore, the thread 5 has a pitch P that corresponds to the distance between two windings of the thread 5 . The thread 5 also has a flank angle α. FIG. 1 also shows the bore hole 6 in the bedrock 7 . The bore hole 6 here has a diameter of D b .
[0035] FIG. 2 shows a first embodiment of an arrangement of the reinforcement and/or anchor bolt 1 in a bore hole 6 that has been drilled in the bedrock 7 . The reinforcement and/or anchor bolt 1 is configured in the area of the bolt head 2 on the bolt shaft 18 in such a way that said bolt shaft does not have a thread 5 , and in another section of the bolt shaft 4 on the bolt end 3 , it has a thread 5 , or else a thread 5 is formed on the bolt shaft 19 . Here, the outer diameter D a of the reinforcement and/or anchor bolt 1 is 20% to 30% larger than the diameter D b of the bore hole 6 . After the bore hole 6 has been drilled, for example, with a drill rod 12 , whereby the bore hole 6 has a constant diameter D b , the reinforcement and/or anchor bolt 1 is screwed into the bore hole 6 in that a torque is applied to the bolt head 2 . Due to the larger outer diameter D a of the reinforcement and/or anchor bolt 1 relative to the diameter D b of the bore hole 6 , the thread 5 cuts its way into the bedrock 7 and a positive connection is created between the thread 5 and the bedrock 7 . In FIG. 2 , the reinforcement and/or anchor bolt 1 is screwed completely into the bore hole 6 and can rest with or without pre-tensioning on a head plate 8 . Here, a force is exerted by the bolt head 2 onto the head plate 8 , preferably with pre-tensioning. FIG. 2 also shows an anchoring depth L of the reinforcement and/or anchor bolt 1 and the length B of the bore hole 6 . The reinforcement and/or anchor bolt 1 in FIG. 2 has a bolt end 3 that is completely configured as a conical tip 9 . The bolt end 3 or the conical tip 9 can also be detachably connected to the rest of the bolt shaft 4 , for example, by means of a screwed connection or a bayonet connection. Through the use of different bolt ends 3 , the reinforcement and/or anchor bolt 1 can be adapted to different types of bedrock 7 . Moreover, the core diameter D i of the bolt shaft 4 is approximately 8% smaller than the diameter D b of the bore hole 6 . As a result, in an advantageous manner, no friction occurs between the bolt shaft 4 and the bedrock 7 when the reinforcement and/or anchor bolt 1 is screwed into the bore hole 6 , so that consequently, the torque that has to be applied to the bolt head 2 to screw in the reinforcement and/or anchor bolt 1 can be reduced.
[0036] When the reinforcement and/or anchor bolt 1 is used in bedrock 7 having a high compressive strength, e.g. solid rock, the bolt shaft 4 is generally configured with a solid profile, whereas, when the reinforcement and/or anchor bolt 1 is used in bedrock 7 having a low compressive strength, e.g. gravel, the bolt shaft 4 is generally configured with a hollow profile. When the reinforcement and/or anchor bolt 1 is used in a bedrock or substrate having a low compressive strength, a hollow profile is already sufficient to absorb the forces that act radially on the bolt shaft 4 . This can save material during the production of the reinforcement and/or anchor bolt 1 . The thread 5 for the reinforcement and/or anchor bolt 1 , especially when the bolt shaft 4 is configured as a hollow profile, can be created, for example, in that a profile wire is wound onto the bolt shaft 4 and laminated into it.
[0037] FIG. 3 shows a second embodiment of the arrangement of the reinforcement and/or anchor bolt 1 in the bedrock 7 . The diameter of the bore hole 6 drilled into the bedrock 7 is larger on an outer bore hole section 11 than on an inner bore hole section 10 . The bolt shaft 19 with the thread 5 is essentially arranged on the inner bore hole section 10 , for instance, with a deviation of less than 40%, 30%, 20%, 10% or 5%. Here, the diameter D b of the bore hole 6 on the inner bore hole section 10 is about 4% to 8% smaller than the outer diameter D a of the reinforcement and/or anchor bolt, so that consequently, a positive connection is created between the thread 5 and the bedrock 7 on the inner bore hole section 10 . The diameter D b on the outer bore hole section 11 is larger here than the outer diameter D a of the reinforcement and/or anchor bolt. As a result, the reinforcement and/or anchor bolt can initially be inserted with a small amount of force into the anchoring area, namely, into the inner bore hole section 10 . Furthermore, this means that a lower and more constant screwing torque has to be applied onto the bolt head 2 , and a better and constant support is possible due to the smaller diameter D b on the inner bore hole section 10 . For the rest, the second embodiment shown in FIG. 3 corresponds to the first embodiment shown in FIG. 2 .
[0038] FIG. 4 shows a third embodiment of an arrangement of the reinforcement and/or anchor bolt 1 in a bore hole 6 that has been drilled in the bedrock 7 . Like in the first embodiment, the bore hole 6 has a constant diameter D b . In contrast to the first embodiment, however, the core diameter D i of the reinforcement and/or anchor bolt 1 is smaller on the bolt shaft 18 without the thread 5 , for example, 2% to 8% smaller than the core diameter D i on the bolt shaft 19 with the thread 5 . The outer diameter D a of the reinforcement and/or anchor bolt 1 on the thread 5 is about 20% to 30% larger than the diameter D b of the bore hole 6 , so that in the third embodiment as well, the thread 5 cuts its way into the bedrock 7 when the reinforcement and/or anchor bolt 1 is screwed into the bore hole 6 , and moreover, as a result, a positive connection can be created between the thread 5 and the bedrock 7 . Due to the fact that the core diameter D i of the reinforcement and/or anchor bolt 1 on the bolt shaft 18 without the thread 5 is smaller than on the bolt shaft 19 with the thread 5 , the torque that is needed on the bolt head 2 can be reduced, since there is less friction between the bolt shaft 4 and the bedrock 7 .
[0039] FIG. 5 shows a perspective view of the drill rod 12 for drilling a bore hole 6 with a varying diameter D b as shown for the second embodiment in FIG. 3 . The drill rod 12 has a drilling crown 13 , a stabilizer 14 , a first boring bar 15 having a small diameter, a boring tool 16 and a second boring bar 17 having a large diameter. Here, for example, the drilling crown 13 , the stabilizer 14 and the first boring bar 15 have a diameter of 15 mm, the boring tool 16 has a diameter of 32 mm, and the second boring bar 17 has a diameter of 18 mm. The diameter of the boring tool 16 is thus larger than the diameter of the second boring bar 17 , and the diameter of the second boring bar 17 is larger than the diameter of the first boring bar 15 .
[0040] All in all, the reinforcement and/or anchor bolt 1 entails major advantages. The force that is to be exerted by the reinforcement and/or anchor bolt 1 into the bedrock 7 is applied by the thread 5 essentially positively into the bedrock 7 . The reinforcement and/or anchor bolt 1 is essentially connected with a positive fit or anchored to the bedrock 7 at its bolt shaft 19 with the thread 5 . Thus, it is possible to dispense with a complicated and disadvantageous anchoring of the reinforcement and/or anchor bolt by means of adhesion or by means of a non-positive connection (expansion). Hence, the reinforcement and/or anchor bolt 1 can be inserted into the bedrock 7 with little technical effort in that first a bore hole 6 is drilled, and subsequently the reinforcement and/or anchor bolt with the thread 5 is screwed into the bore hole 6 . | With a reinforcement and/or anchor bolt ( 1 ) that can be used in mining and/or tunnel construction and that is to be screwed into bedrock ( 7 ), and that includes a bolt head ( 2 ), a bolt end ( 3 ), a bolt shaft ( 4 ) and a thread ( 5 ) that is at least partially configured on the bolt shaft ( 4 ), the objective is to attach the reinforcement and/or anchor bolt ( 1 ) inexpensively and reliably to the bedrock ( 7 ) with little technical effort. A ratio of the length of the reinforcement and/or anchor bolt ( 1 ) to the outer diameter of the reinforcement and/or anchor bolt ( 1 ) is greater than 20. | 4 |
CROSS-REFERENCE TO RELATED APPLICATION
The present application claims the benefit under 35 U.S.C. §119(e) of provisional patent application Ser. No. 60/583,614, filed Jun. 30, 2004, the contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
In one of its aspects, the present invention relates to a radiation sensor device. In another of its aspects, the present invention relates to a fluid treatment system comprising a novel radiation sensor device. In yet another of its aspects, the present invention relates to a radiation sensor module for use in a radiation sensor device.
2. Description of the Prior Art
Optical radiation sensors are known and find widespread use in a number of applications. One of the principal applications of optical radiation sensors is in the field of ultraviolet radiation fluid disinfection systems.
It is known that the irradiation of water with ultraviolet light will disinfect the water by inactivation of microorganisms in the water, provided the irradiance and exposure duration are above a minimum “dose” level (often measured in units of microwatt seconds per square centimeter). Ultraviolet water disinfection units such as those commercially available from Trojan Technologies Inc. under the tradenames Trojan UV Max™, Trojan UV Logic™ and Trojan UV Swift™, employ this principle to disinfect water for human consumption. Generally, water to be disinfected passes through a pressurized stainless steel cylinder which is flooded with ultraviolet radiation. Large scale municipal waste water treatment equipment such as that commercially available from Trojan Technologies Inc. under the trade-names UV3000™, UV3000 Plus™ and UV4000™, employ the same principal to disinfect waste water. Generally, the practical applications of these treatment systems relates to submersion of treatment module or system in an open channel wherein the wastewater is exposed to radiation as it flows past the lamps. For further discussion of fluid disinfection systems employing ultraviolet radiation, see any one of the following:
U.S. Pat. No. 4,482,809, U.S. Pat. No. 4,872,980, U.S. Pat. No. 5,006,244, U.S. Pat. No. 5,418,370, U.S. Pat. No. 5,539,210, and U.S. Pat. No. Re 36,896.
In recent years, such systems have also been successfully used for other treatment of water—e.g., taste and odour control, TOC (total organic carbon) control and/or ECT (environmental contaminant treatment).
In many applications, it is desirable to monitor the level of ultraviolet radiation present within the water under treatment. In this way, it is possible to assess, on a continuous or semi-continuous basis, the level of ultraviolet radiation, and thus the overall effectiveness and efficiency of the disinfection process.
It is known in the art to monitor the ultraviolet radiation level by deploying one or more passive sensor devices near the operating lamps in specific locations and orientations which are remote from the operating lamps. These passive sensor devices may be photodiodes, photoresistors or other devices that respond to the impingent of the particular radiation wavelength or range of radiation wavelengths of interest by producing a repeatable signal level (in volts or amperes) on output leads.
Conventional ultraviolet disinfection systems often incorporate arrays of lamps immersed in a fluid to be treated. Such an arrangement poses difficulties for mounting sensors to monitor lamp output. The surrounding structure is usually a pressurized vessel or other construction not well suited for insertion of instrumentation. Simply attaching an ultraviolet radiation sensor to the lamp module can impede flow of fluid and act as attachment point for fouling and/or blockage of the ultraviolet radiation use to treat the water. Additionally, for many practical applications, it is necessary to incorporate a special cleaning system for removal of fouling materials from the sensor to avoid conveyance of misleading information about lamp performance.
International Publication Number WO 01/17906 [Pearcey] teaches a radiation source module wherein at least one radiation source and an optical radiation sensor are disposed within a protective sleeve of the module. This arrangement facilitates cleaning of the sensor since it is conventional to use cleaning systems for the purposes of removing fouling materials from the protective sleeve to allow for optimum dosing of radiation—i.e., a separate cleaning system for the sensor is not required. Further, since the optical radiation sensor is disposed within an existing element (the protective sleeve) of the radiation source module, incorporation of the sensor in the module does not result in any additional hydraulic head loss and/or does not create a “catch” for fouling materials.
Conventional radiation sensor devices typically have been designed as field units with the detector (e.g., photodiodes, photoresistors and the like) being calibrated prior to assembly into the sensor body. The sensor body is then sealed in a conventional manner to prevent ingress of fluid.
Recently, the United States Environmental Protection Agency (“USEPA”) published guidelines for ultraviolet radiation sensor devices for use in municipal drinking water treatment systems. These published guidelines prescribe the use of one sensor per radiation source in municipal drinking water treatment water systems. The published guidelines also prescribe: the use of one or more filters to limit the sensitivity of the detector (e.g., photodiodes, photoresistors and the like) to the germicidal range, limitations on accuracy/tracability of the sensor device, requirements for regular sensor recalibration and a requirement that UV intensity sensors should view a point along the length of the lamp that is between the electrodes (lamp end) and within 25% of the arc length away from the electrode.
The incorporation of a filter into a sensor device can create a degree of uncertainty if it is not possible to calibrate the specific detector (e.g., photodiodes, photoresistors and the like) paired with the specific filter. If the specific detector is calibrated alone before being paired with the specific filter in the final application, small variations in the composition of the filter and/or position of the filter could impact the sensitivity of the detector and reduce the accuracy of the sensor when compared to an absolute irradiance or radiation dose.
In conventional ultraviolet radiation sensor devices, it is not possible to physically adjust the calibration set point of the detector without first completely dissembling the sensor device.
Accordingly, there remains a need in the art for a sensor device ideally suited to match a specific sensor to a specific radiation source in a 1:1 ratio and to allow for ready removal of the sensor device, verification of calibration of the detector (e.g., photodiodes, photoresistor and the like) and adjustment thereof as required.
SUMMARY OF THE INVENTION
It is an object of the present invention to obviate or mitigate at least one of the above-mentioned disadvantages of the prior art.
It is an object of the present invention to provide a novel radiation sensor device which obviates or mitigates at least one of the above-mentioned disadvantages of the prior art.
It is another object of the present invention to provide a novel radiation sensor module which obviates or mitigates at least one of the above-mentioned disadvantages of the prior art.
Accordingly, in one of its aspects, the present invention provides a radiation sensor device comprising a housing and a plurality of radiation sensor modules secured to the housing, each radiation sensor module comprising a radiation sensor arranged to detect radiation incident on the radiation sensor.
In another of its aspects, the present invention provides a fluid treatment system comprising a fluid treatment zone having disposed therein a plurality of radiation sources and the radiation sensor device a radiation sensor device comprising a housing and a plurality of radiation sensor modules secured to the housing, each radiation sensor module comprising a radiation sensor arranged to detect radiation incident on the radiation source module.
In yet another of its aspects, the present invention provides radiation sensor module comprising a module housing, a radiation sensor secured to the module, a radiation transparent window through which incident radiation may pass to contact the radiation sensor and a calibration element for calibration of a signal received from the radiation sensor.
Thus, the present inventors have discovered a novel radiation sensor device comprising a housing and a plurality of radiation sensor modules secured to the housing. The radiation sensor source modules are, in effect, repeating units that are preferably arranged annularly with respect to the housing so that the ratio of radiation sensor modules to radiation sources is 1:1.
The plurality of radiation sensor modules are positioned on the housing in such a manner as to be able to view a length of lamp that is within 25% of the arc length as measured form a lamp end or electrode.
By using the configuration of sensors as described herein, it is possible to position at least 2 or more sensors on a single support and be positioned to view a lamp within the region 25% of the arc length away from the electrode.
Preferably, each radiation sensor module contains an entire so-called optical train (e.g., one or more of photodiodes, photoresistors, filters, apertures, calibration elements, signal amplification elements, signal transmitter elements and the like) to allow for calibration of the detector without disassembling all the components of the module.
Thus, a given radiation sensor module may be readily removed from the radiation sensor device and calibration of the detector or radiation sensor (e.g., photodiodes, photoresistor and alike) can be readily verified and adjusted, if necessary, all without the need to disassemble the device.
The present radiation sensor device may be readily retrofitted into existing ultraviolet radiation water treatment systems such that these systems are in compliance with the guidelines recently published by the USEPA.
In a first preferred embodiment of the present invention, the optical radiation sensor comprises a radiation detector and a body portion. The radiation detector contains a photodiode or other sensing element which is able to detect and respond to incident radiation. The body portion houses one or more of electronic components, mirrors, optical components and the like. The optical radiation sensor is disposed within a protective sleeve. The protective sleeve may comprise first radiation transparent region in substantial alignment with the radiation detector (or sensing element) and a radiation opaque second region which is in substantial alignment with the body portion of the sensor. Those of skill in the art will also appreciate that the sensing element may be protect by its own integral protective (e.g., quartz) sleeve which may be positioned inside a lamp sleeve, the latter being coated to provide thermal protection.
Throughout this specification, reference is made to a preferred embodiment of the present invention with a protective sleeve containing a “radiation transparent” region and a “radiation opaque” region. Of course, those of skill in the art will recognize that these terms will depend on the nature of radiation present in the radiation field. For example, if the present invention is employed in an ultraviolet (UV) radiation field, it is principally radiation in this portion of the electromagnetic spectrum to which the “radiation opaque” region should be opaque—i.e., the radiation opaque region may be transparent to radiation having characteristics (e.g., wavelength) different than radiation to be blocked. By “radiation opaque” is meant that no more than 5%, preferably no more than 4%, preferably no more than 3%, of the radiation of interest (e.g., this could be radiation at all wavelengths or at selected wavelengths) from the radiation field will pass through the region and impinge on the radiation sensing element. Thus, in some embodiments of the invention, all radiation (e.g., one or more of UV, visible and infrared radiation) present in the radiation field will be blocked to achieve thermal protection of the sensor in addition to eliminating impingement of incident radiation. In other embodiments of the invention, a pre-determined portion of radiation (e.g., one or two of UV, visible and infrared radiation) present in the radiation field will be blocked to achieve thermal protection of the sensor while allowing impingement of a pre-determined portion of incident radiation.
Depending on the radiation field in question, the radiation opaque region may be provided on the protective sleeve in a number of different ways. For example, it is possible to utilize a metallic layer disposed on the interior or exterior of the protective sleeve to confer radiation opacity to the protective sleeve. The metallic layer may compromise at least one member selected from the group comprising stainless steel, titanium, aluminum, gold, silver, platinum, nitinol and mixtures thereof. Alternatively, a ceramic layer may be disposed on the interior or the exterior of the protective sleeve to confer radiation opacity to the protective sleeve. In yet another embodiment, the radiation opaque layer may comprise of porous metal structure and combination with a metal material. The porous metal structure may contain a metal selected from the group of metallic layers referred to above. Examples of non-metal materials in this embodiment of the radiation opaque layer include an elastomer or other material (e.g., PTFE Teflon) secured to the porous metal structure.
In another embodiment, radiation specific opacity may be conferred to the protective sleeve by placement in the interior or the exterior thereof a filter layer which will exclude deleterious radiation but allow radiation of interest to pass through the protective sleeve to be detected by the sensor. Thus, again using the example of an ultraviolet radiation sensor, in many cases, the wavelength of interest for detection is in the range of from about 210 to about 300 nm. It is possible to utilize a layer made from a filter material which will allow substantially only radiation in this range through the protective sleeve allowing detection of radiation while minimizing or preventing thermal build-up compared to the situation where all radiation from the radiation field is allowed to enter the protective sleeve. Non-limiting examples of suitable such filter materials may be made from heavy metal oxides of varying thickness and/or numbers of layers depending on the type of radiation being sensed. Those of skill in the art will further appreciate that the optical radiation sensor may have a thermal opaque region as well as a filtered region to protect the sensing element (e.g., photodiode) of the optical radiation sensor.
The provision of the radiation transparent region may take a number of forms. This can be achieved by physically placing a metal layer or depositing a metal layer on the interior or exterior of the protective sleeve such that the radiation transparent region has a desired shape. For example, the radiation transparent region may have an annular shape, a non-annular shape, a rectilinear shape, a curvilinear shape, a substantially circular shape and the like. Further, the radiation opaque region may be designed to provide a plurality (i.e., two or more) of radiation transparent regions.
The manner of disposing the radiation opaque region on the protective sleeve is not particularly restricted. For example, the radiation opaque layer may be adhered, mechanically secured or friction fit to the protective sleeve. The latter two approaches work particularly well when the radiation opaque layer is disposed on the exterior of the protective sleeve. For the interior of the protective quartz sleeve, it is possible to insert a split expanding sleeve. The first approach is preferred in the case where the radiation opaque layer is disposed on the interior or exterior of the protective sleeve. This approach may be used to deposit a fully or selective radiation opaque layer, for example, via vapor deposition, electron beam gun deposition or the like of a metal oxide (e.g., silicon dioxide, titanium dioxide, etc.).
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention will be described with reference to the accompanying drawings, wherein like reference numerals denote like parts, and in which:
FIG. 1 illustrates a perspective view of a preferred embodiment of the present radiation sensor device having the radiation sensor modules removed therefrom for illustrative purposes;
FIG. 2 illustrates a perspective view of a radiation sensor module used in FIG. 1 shown in a disassembled form viewed from an outward perspective; and
FIG. 3 illustrates a perspective view of a radiation sensor module used in FIG. 1 shown in a disassembled form viewed from an inward perspective;
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIG. 1 there is illustrated a radiation sensor device 100 comprising a housing 105 and a trio of radiation sensor modules 110 , 115 , 120 . As will be discussed with reference to FIGS. 2 and 3 , radiation sensor modules 110 , 115 , 120 are of identical construction.
Disposed in housing 105 is a cavity 125 to receive each of radiation sensor modules 110 , 115 , 120 (i.e., one cavity 125 is provided for each radiation sensor module). As shown, cavity 125 and an adjacent cavity are staggered with respect to one another along a longitudinal axis of housing 105 resulting in staggered placement of radiation sensor modules along this axis. This allows for miniaturization of housing 105 on one hand while providing for adequate space for electrical connections to be made to each of radiation sensor modules 110 , 115 , 120 . This also allows for the radiation sensors modules 110 , 115 , 120 to have their respective aperture windows 152 located toward one end of the housing 105 .
Once each of radiation sensor modules 110 , 115 , 120 are seated in their respective cavities, a protective sleeve (not shown) may be placed over housing 105 between a first end 135 and a second end 140 thereof. The protective sleeve may be sealed with respect to first end 135 and second end 140 in a conventional manner (not shown).
With reference to FIGS. 2 and 3 , there is shown an exploded view of radiation sensor module 110 . As described above, the construction of radiation sensor module 110 is the same as that of radiation sensor modules 115 , 120 .
Thus, as shown in FIG. 2 , radiation sensor module 110 comprises a module housing 150 and a printed circuit board 155 . Disposed in module housing 150 is a radiation transparent window (sometimes referred to in the art as an “aperture”) 152 through which incident radiation may pass.
Interposed between module housing 150 and printed circuit board 155 are the following elements, in sequence: a Teflon™ washer 160 , an optional radiation filter 165 (e.g., quartz, a diffraction grating and the like), a retaining ring 170 , an aperture 175 and an aperture support 180 . As shown, aperture support 180 is correctly located through the use of pins 185 and detector seat 190 on printed circuit board 155 .
Module housing 150 and printed circuit board 155 can be secured to one another in a conventional manner—e.g., through the use of mechanical means such as screws, rivets and the like. Printed circuit board 155 further comprises a locating hole 195 which receives locator 200 on module housing 150 ( FIG. 3 ).
Printed circuit board 155 comprises a complete so-called optical train to allow sensor module 110 to function as a sensor device. Thus, the following components are disposed on printed circuit board 155 in suitable electrical connection: a detector 205 (e.g., a photodiodes, a photoresistor and the like), a signal amplifier 210 , a gain adjustment potentiometer 215 (this is equivalent to a single calibration element), a current loop transmitter 220 , a pair of reverse polarity protection diodes 225 and a Molex™ connector 230 .
Of course, it is possible to dispose additional components on printed circuit board 155 depending on the desired functionality of the sensor device. The important feature is that on a given radiation sensor module 110 , it is possible to pair a given filter 165 with a given detector 205 and calibrate the latter through adjustment of potentiometer 215 without the need to disassemble the entire radiation sensor module. To the knowledge of the present inventors, a device having these features is heretofore unknown.
Module housing 150 comprises a locating pin 235 for engagement with a complementary shaped hole (not shown) in housing 105 of radiation sensor device 100 . The use of such a locating pin/hole combination allows for correct placement of each radiation sensor module in radiation sensor device 100 .
While this invention has been described with reference to illustrative embodiments and examples, the description is not intended to be construed in a limiting sense. Thus, various modifications of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to this description. It is therefore contemplated that the appended claims will cover any such modifications or embodiments.
All publications, patents and patent applications referred to herein are incorporated by reference in their entirety to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated by reference in its entirety. | The invention relates to a radiation sensor device comprising a housing and a plurality of radiation sensor modules secured to the housing. Each radiation sensor module comprises a radiation sensor arranged to detect radiation incident on the radiation source module. Preferably, each radiation sensor module contains an entire so-called optical train to allow for calibration of the detector (e.g., photodiodes, photoresistors and the like) without disassembling all the components of the module. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to Korean Patent Application No. 10-2013-0138146, filed on Nov. 14, 2013, and all the benefits accruing therefrom under 35 U.S.C. §119, the contents of which in its entirety are herein incorporated by reference.
BACKGROUND
[0002] 1. Field
[0003] The present disclosure relates to a bank erosion protecting system using an embedded roll mat, and more particularly, to a bank erosion protecting system having a roll mat wound in a roll type and embedded at a top portion of a bank so that the roll mat automatically covers the bank slope when the bank in the main channel is eroded and failed due to a bank erosion or bank failure.
[0004] 2. Description of the Related Art
[0005] A river side below a bank formed at a river, channel or reservoir may be eroded due to a flood or typhoon (hurricane), which results in erosion of the bank. Generally, waterfront facilities such as trails, sport outfits, washrooms or the like are installed at the rear of the top of a bank. Therefore, if the bank is eroded, the waterfront facilities will be seriously damaged.
[0006] In order to prevent bank erosion, concrete blocks may be installed at a bank slope, as disclosed in Korean Patent Registration No. 10-0477379. However, the install of such blocks at a bank slope is not suitable for protecting an ecologically stabilized bank. If an artificial structure such as blocks is installed at an ecologically stabilized bank slope, the bank slope becomes an inappropriate place for the growth of animals or plants.
SUMMARY
[0007] The present disclosure is directed to providing a system for preventing an occurrence of abrupt bank erosion to ensure enough time to take an additional protective action to a bank.
[0008] In addition, the present disclosure is directed to providing a system for minimizing ecological and environmental disturbance in the bank even though a facility for preventing bank erosion is installed at the bank slope.
[0009] In one aspect of the present disclosure, there is provided a bank erosion protecting system, which includes: a roll mat having one end wound into a roll shape and embedded in the ground at a top of a bank, wherein one end of the roll mat wound into a roll shape is disposed toward a river and the other end of the roll mat is disposed at the back of the bank in an unrolled state; and riprap installed on the roll mat, wherein when a bank slope collapses, soil supporting the rolled portion of the roll mat is swept so that the rolled portion of the roll mat is unrolled and spread to cover the bank slope, and the riprap or stone also covers the roll mat spread over the bank slope, thereby preventing the bank slope from additionally collapsing.
[0010] In the present disclosure, if a bank slope starts collapsing, a roll mat embedded in the bank starts unrolling to cover the bank slope, and subsequently riprap or stone contained in a trench flows down to the bank slope. Therefore, it is possible to efficiently preventing the bank slope from additionally collapsing.
[0011] In addition, in the present disclosure, since the collapsing bank slope is covered by the roll mat and the riprap or stone, even though water swells to the bank slope, it is possible to effectively prevent soil of the bank slope from collapsing due to the water swelling or sediment winnowing.
[0012] In particular, in the present disclosure, when a bank slope starts collapsing, the collapsing of the bank slope may be rapidly intercepted by means of the roll mat and the riprap or stone. Therefore, it is possible to permanently prevent bank erosion and also easily ensure enough time to stably protect the bank until an additional work for recovering a collapsed bank starts.
[0013] In the present disclosure, it is just needed to excavate only a top portion of the bank (a floodplain). Therefore, even though the bank slope is already ecologically stabilized, it is possible to take a measure to prevent collapse of the bank slope in an easy and rapid way without disturbing ecologic environments.
[0014] In the present disclosure, the roll mat may be wound and bound again into a roll shape not to be unrolled again, and after a collapsed bank slope is recovered, riprap or stone may be installed to be supported by the roll mat for preventing sediment winnowing through riprap. By doing so, the roll mat may be very usefully recycled.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a schematic perspective view showing a roll mat and riprap installed at a bank.
[0016] FIG. 2 is a schematic cross-sectional view taken along the line A-A of FIG. 1 .
[0017] FIG. 3 is a schematic perspective view showing a trench formed at a top of a bank to install a roll mat and riprap or stone at the bank.
[0018] FIG. 4 is a schematic cross-sectional view taken along the line B-B of FIG. 3 .
[0019] FIG. 5 is a schematic perspective view showing that a roll mat is disposed at the trench as depicted in FIG. 1 after the state of FIG. 3 .
[0020] FIG. 6 is a schematic cross-sectional view taken along the line C-C of FIG. 5 .
[0021] FIG. 7 is a schematic cross-sectional view showing that a bank starts collapsing.
[0022] FIG. 8 is a schematic cross-sectional view showing that the roll mat is unrolled after the state of FIG. 7 to cover a collapsed bank slope.
[0023] FIG. 9 is a schematic cross-sectional view showing that the riprap or stone collapses after the state of FIG. 8 to cover the roll mat.
[0024] FIG. 10 is a schematic cross-sectional view showing that a roll mat unrolled over the bank slope is wound and bound again into a roll state for recycling.
DETAILED DESCRIPTION
[0025] FIG. 1 is a schematic perspective view showing a roll mat and riprap installed at a bank according to the present disclosure. FIG. 2 is a schematic cross-sectional view taken along the line A-A of FIG. 1 . For reference, in the specification, the term “river” is used to have a meaning including artificial channels and reservoirs as well as natural rivers.
[0026] In the present disclosure, a roll mat 10 is embedded in the ground at a top of a bank (a floodplain). One side of the roll mat 10 is wound into a roll shape, and the rolled portion of the roll mat 10 is disposed toward a river. When being wound into a roll shape, one side of the roll mat 10 is rolled so that its end is rolled upwards as shown in FIGS. 1 and 2 , which is more advantageous in spreading the roll mat 10 over the bank slope when the bank collapses.
[0027] In the embodiment depicted in FIG. 2 , the other side of the roll mat 10 is unrolled toward the back of the bank, and riprap 20 is piled over the unrolled portion of the roll mat 10 , so that the roll mat 10 and the riprap 20 will be embedded together in the ground.
[0028] FIG. 3 is a schematic perspective view showing a trench formed at a top of a bank to install the roll mat 10 and the riprap 20 . FIG. 4 is a schematic cross-sectional view taken along the line B-B of FIG. 3 . As shown in FIGS. 3 and 4 , the top surface of the bank 100 is excavated to form a trench 110 at which the roll mat 10 is to be disposed. In the present disclosure, the bank is not entirely dug or damaged, but just the top surface of the bank is excavated to a certain depth to form the trench 110 while remaining the bank slope as it is. In particular, in the present disclosure, the trench 110 may be formed at the bank only in a region where bank erosion is expected. For example, in case of a river, based on a direction along which the river flows (or, a longitudinal direction), the trench 110 may be excavated at the top of the bank in the longitudinal direction only for a region where bank collapse is expected, as shown in FIGS. 3 and 4 .
[0029] FIG. 5 is a schematic perspective view showing that the roll mat 10 is disposed at the trench 110 as depicted in FIG. 1 . FIG. 6 is a schematic cross-sectional view taken along the line C-C of FIG. 5 . As shown in FIGS. 5 and 6 , after the trench 110 is completely formed, the roll mat 10 is disposed in the trench 110 . When the roll mat 10 is disposed in the trench 110 , the rolled portion of the roll mat 10 is located toward the river, and the other end of the roll mat 10 is unrolled into a flat state and located at the bottom of the trench 110 .
[0030] After the roll mat 10 is disposed in the trench 110 , the riprap 20 is placed on the unrolled portion of the roll mat 10 in the trench 110 as shown in FIGS. 1 and 2 and the trench 100 is filled with the riprap 20 .
[0031] FIG. 7 is a schematic cross-sectional view showing that the bank slope has geometric changes by erosion or failure in the state of FIG. 2 . As shown in FIG. 7 , if a flood occurs, the bank slope has geometric changes by erosion or failure, and accordingly soil of the bank supporting the rolled portion of the roll mat 10 is swept. FIG. 8 is a schematic cross-sectional view showing a state after the FIG. 7 . If the soil supporting the roll mat 10 is swept, the rolled portion of the roll mat 10 is unrolled as shown in FIG. 8 , and accordingly the roll mat 10 covers the bank slope. As the rolled portion of the roll mat 10 is unrolled, the unrolled portion of the roll mat 10 covers a swept surface of the bank slope.
[0032] The riprap 20 placed on the roll mat 10 collapses onto the roll mat 10 to cover the roll mat 10 unrolled over the bank slope. FIG. 9 is a schematic cross-sectional view showing that the riprap 20 covers the roll mat 10 unrolled over the bank slope after the state of FIG. 8 .
[0033] As described above, in the present disclosure, if the bank slope collapses, the rolled portion of the roll mat 10 is unrolled so that the roll mat 10 covers the bank slope, and along with it, the riprap 20 placed on the roll mat 10 also collapses onto the roll mat 10 to cover the roll mat 10 . In this way, the bank slope which is likely to additionally collapse is covered and protected by the roll mat 10 and the riprap 20 . Therefore, it is possible to efficiently prevent the bank slope from additionally collapsing.
[0034] If a level of the river rises due to a flood or the like, water may swell to the bank slope from the inside of the bank. In the present disclosure, since the collapsing bank slope is covered by the roll mat 10 and the riprap 20 , even though water swells to the bank slope, it is possible to effectively prevent soil of the bank slope from being swept due to water swelling or sediment winnowing by water.
[0035] In the present disclosure, when the bank slope starts collapsing, collapsing of the bank slope may be rapidly intercepted by means of the roll mat 10 and the riprap 20 . Therefore, it is possible to permanently prevent bank erosion and also easily ensure enough time to stably protect the bank until an additional work for recovering a collapsed bank starts.
[0036] In particular, when the roll mat 10 and the riprap 20 are installed, it is just needed to excavate only a top surface of the bank. Therefore, even though the bank slope is already ecologically stabilized, it is possible to take a measure to prevent possible collapse of the bank slope in an easy and rapid way without disturbing ecologic environments.
[0037] FIG. 10 is a schematic cross-sectional view showing that after the riprap 20 covering the roll mat 10 is removed, the roll mat 10 unrolled over the bank slope is wound and bound again into a roll state so as not to be unrolled again. In the present disclosure, the roll mat 10 may be wound and bound again into a roll shape not to be unrolled again, and after the collapsed bank slope is recovered, riprap 20 may be installed to be supported by the roll mat 10 . By doing so, the roll mat 10 may be very usefully recycled.
[0038] The roll mat 10 may be made of natural fiber. In order to recover the bank slope, soil may be placed on the roll mat 10 and the riprap 20 spread over the bank slope. If the roll mat 10 is made of natural fiber, the roll mat 10 may be recycled as a material for survival and growth of plants at the recovered bank slope. | Disclosed is a bank erosion protecting system having a roll mat wound in a roll type and embedded at a top portion of a bank so that when the bank slope starts collapsing, the roll mat may automatically cover the bank slope. | 4 |
This invention relates to fusible fiber/microfine fiber laminated materials and, more particularly, to sterile packaging barriers which are impermeable to the passage of microorganisms and fluids, but which are gas-permeable, smooth surfaced and, thus highly printable.
BACKGROUND OF THE INVENTION
Articles intended for medical use, such as intravenous catheters, for instance, are conventionally stored in containers such as formed polymer blisters, which containers are covered with a barrier material (or lid) which permits the infusion of a sterilization gas, such as steam or ethylene oxide, but which nevertheless provides a barrier substrate to aqueous fluid. A flash-spun polyolefin produced by DuPont and known by the trademark Tyvek, is currently in extensive use as such lid-stock material for sterile packaging applications. Tyvek offers little resistance to the temperatures encountered in steam sterilization and it is also rather difficult to print due to its uneven surface and strongly hydrophobic nature. Although Tyvek is strong and has good tear properties, it possesses a rather low-level permeability to gases.
Treated paper may also be used as a sterile packaging barrier and has the advantage of possessing a very fine pore size. However, such treated paper tears easily, has a lack of wet strength and does not possess adequate peel strength. The present invention provides a strong laminated fabric that provides excellent barrier properties as well as highly printable surfaces. In addition, the present composite, nonwoven fabric demonstrates improved resistance to steam sterilization. Further, the present fabric can be effectively sterilized at lower pressures and in a shorter time than Tyvek or paper.
The laminate of the present invention preferably comprises at least one ply of hydrophobic microfine fibers, fuse bonded to a layer of conjugate fibers by means of smooth calendering. The surface of the conjugate fiber fabric is highly printable due to its extreme uniformity. The microfiber side of the laminate provides excellent barrier properties to aqueous fluids and is susceptible to graphic printing and, in addition, provides a surface which is compatible with existing seal-coat systems that are required for heat sealing of this material to a formed polymer blister. However, the seal-coat printing on the conjugate fiber side is preferred. Conventionally, the seal-coat system consists of a heat seal resin (such as ethylene/vinyl acetate hot melt) which is printed on the fabric which is to be sealed to a polymer blister. The heat seal resin acts as a bonding medium between the barrier material and the polymer blister. Preferably, the seal-coat is printed onto the conjugate material in discrete dots so as not to occlude the entire fabric.
The laminate of the present invention comprises at least one layer of microfine fibers which are compatible with and fuse bonded to at least one layer of conjugate fibers, and, thus, the laminate is extremely resistant to delamination. Furthermore, in view of the fact that the laminate of the present invention is produced by calendering between heated rollers with direct heat being applied to both surfaces of the fabric, this brings about a very regular surface and increases the strength and abrasion resistance properties of the composite.
The laminated material of the present invention is primarily intended as a sterile packaging barrier, the primary use being for lid-stocks for medical packaging application. However, it could also be adapted for use as a surgical drape and, in addition, the present laminate may be used in the central supply room of a hospital for wrapping surgical instruments prior to sterilization with steam or ethylene oxide. Furthermore, the laminate of the present invention may be utilized in the form of a sealed envelope, thus dispensing entirely with any polymer blister.
Certain barrier materials are known which consist of non-woven layers of heat fusible fibers fused to nonwoven fabrics comprising multiple plies of microfine fibers. However, in producing this type of fabric, the heat fusible fibers are fused so that the integrity of the fibers is destroyed. The present invention provides at least one hydrophobic microfine fiber layer fuse bonded to at least one layer of conjugate fibers having a low-melting sheath and a high-melting core. The sheaths of the conjugate fibers are fuse bonded to the hydrophobic microfine fiber layer at a temperature below the melt temperature of the cores of the conjugate fibers so that the cores retain their initial fiber-like integrity. Furthermore, in view of the fact that the hydrophobic microfine fiber layer is compatible with the conjugate fiber sheath, excellent fusion takes place when the two layers are bonded together by smooth calendering or other heat means.
The microfine fibers utilized in the present invention are preferably produced by melt blowing. However, microfine fibers can also be produced, for instance, by a centrifugal spinning operation (see Vinicki's U.S. Pat. No. 3,388,194).
THE PRIOR ART
The Kitson et al. U.S. Pat. No. 4,196,245 describes a composite nonwoven fabric which comprises at least two hydrophobic plies of microfine fibers and at least one nonwoven cover ply. There is no disclosure in Kitson et al. concerning the use of conjugate fibers for the nonwoven cover ply. Furthermore, the Kitson et al. fabric is cloth-like and is, thus, not easily printable.
Floden, in U.S. Pat. No. 3,837,995, describes a web containing one or more layers of melt blown fibers and one or more layers of larger diameter natural fibers. No conjugate fibers are disclosed.
Prentice, in U.S. Pat. Nos. 3,795,571 and 3,715,251, describes a nonwoven sheet of melt blow thermoplastic fibers comprising a plurality of laminated nonwoven sheets of melt blown thermoplastic fibers. No cover ply of conjugate fibers is disclosed.
Marra, in U.S. Pat. No. 4,302,495, discloses a nonwoven fabric-like material comprising at least one integrated mat of generally discontinuous thermoplastic polymeric microfibers and at least one layer of nonwoven continuous, linearly oriented thermoplastic netting having at least two sets of strands wherein each set of strands crosses another set of strands at a fixed angle and having uniformly-sized openings, said netting and said integrated mat bonded together by heat and pressure to form a multilayer, nonwoven fabric of substantially uniform thickness. No smoothly calendered layer of conjugate fibers is disclosed.
Brock et al., in U.S. Pat. No. 4,041,203, discloses a nonwoven fabric-like material comprising a web of substantially continuous and randomly deposited, molecularly oriented filaments of a thermoplastic polymer and an integrated mat of generally discontinuous, thermoplastic polymeric microfibers; said web and mat being united together at intermittent, discrete bond regions formed by the application of heat and pressure to thereby provide a unitary structure having textile-like appearance and drape characteristics. No smooth calendered layer of conjugate fibers is disclosed.
Schultheiss et al., in U.S. Pat. No. 4,180,611, discloses a nonwoven fabric having a smooth surface for use as support material for semipermeable membranes comprising a support mat into which at least one surface thereof, an open structured, continuous covering layer of fine thermoplastic particles is calendered. There is no disclosure of the laminate of the present invention.
Wahlquist et al., in U.S. Pat. No. 4,379,192, discloses an absorbent impervious barrier fabric in the form of a laminate that has a fibrous section including a mat of polymeric melt blown microfibers and an impervious polymeric film adjacent to said mat. The fibrous section and the film are united in compacted bond regions formed by the application of heat and pressure.
Thompson, in U.S. Pat. No. 3,916,447, discloses a protective covering having at least one layer of synthetic polymeric microfibers bonded to at least one other layer of cellulosic fibers.
Newman in U.S. Pat. No. 3,973,067 discloses nonwoven fabrics produced by applying to a dry-laid fibrous web, an aqueous dispersion of ultra-short fibers, said ultra-short fibers being coated with a polymeric binder and being suspended in an aqueous phase which is substantially free of binder.
Krueger, in U.S. Pat. No. 4,042,740, discloses webs of blown microfibers having a network of compacted, high density regions and pillowed, low-density regions which are reinforced by a mesh of filaments used to collect the web.
Ikeda et al., in U.S. Pat. No. 4,146,663, discloses a composite fabric useful as a substratum for artifical leather, comprising a woven or knitted fabric and at least one nonwoven fabric firmly bonded to the woven or knitted fabric.
Bornslaeger, in U.S. Pat. No. 4,374,888, discloses a laminate of nonwoven fabric suitable for the manufacture of tents, tarpaulins and the like. The laminate includes an outer, spunbonded layer, an inner microporous, melt blown layer and on the unexposed surface, another nonwoven layer. No cover ply of conjugate fibers is disclosed.
Nakamae et al., in U.S. Pat. No. 4,426,421 disclose a multilayer composite sheet useful as a substrate for artificial leather comprising at least three fibrous layers, namely, a superficial layer consisting of a spun-laid web, an intermediate layer consisting of a web of staple fibers and a base layer consisting of woven or knitted fabric. The three fibrous layers are superimposed on each other and combined together in such a manner that a portion of the fibers in each layer penetrates into the adjacent layers and becomes entangled three-dimensionally with the fibers in the adjacent layers.
Malaney, in U.S. Pat. No. 4,508,113, discloses microfine fiber laminated materials, specially useful for absorbent disposable drapes which are impermeable to the passage of microorganisms and fluids. Said laminated material comprises at least one layer of conjugate fibers bonded to a first ply of microfine fibers as well as at least one additional ply of microfine fibers, the first ply of microfine fibers being thermoplastic and possessing a lower melt temperature than the additional ply of microfine fibers. The present invention differs therefrom in being smooth calendered, repellent treated, and requiring only one ply of microfine fibers although additional layers thereof may be present. This smoother calendering improves the printability and abrasion resistance as well as the strength properties of the laminate of the present invention. The repellent treatment of the present invention improves liquid resistance and peelability without adversely affecting printability. The term "repellent" as used herein, is intended to refer to a repellent binder, a repellent finish or a mixture of both.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a water-impervious, smooth-surfaced, gas-permeable, bacterial barrier, repellent treated, laminated material comprising at least one layer of conjugate fibers, said layer of conjugate fibers having a first face and an opposite face, said conjugate fibers being composed of a lower melting component and a higher melting component, wherein a substantial proportion of the surfaces of said conjugate fibers comprises said lower melting component, said lower melting component of said conjugate fibers which lie on said first face being fuse bonded to at least one hydrophobic ply of thermoplastic microfine fibers having a fiber diameter of up to 50 microns, said lower melting component of said conjugate fibers having been fuse bonded at a temperature below the melt temperature of said higher melting component of said conjugate fibers so that the latter component retains its initial fiber-like integrity, said material having been treated with a water repellent. Preferably, the lower melting component of the conjugate fibers is compatible with the hydrophobic microfine fibers, the laminated material being highly compacted or fully contacted and also resistant to delamination and resistant to steam sterilization. As pointed out above, the repellent utilized in treating the laminated material of the present invention comprises a repellent binder, a repellent finish or preferably a mixture of both.
The non-wettable material of the present invention possesses an increased hydrostatic head, including an increased fabric strength and dimensional stability, surface abrasion resistance and tolerance to peeling as compared to the untreated material.
In accordance with an embodiment of the present invention, there is provided a water-impervious, smooth-surfaced, gas-permeable, bacterial barrier, repellent treated, laminated material comprising at least one inner hydrophobic microfine fiber ply sandwiched between two layers of conjugate fibers, each of said layers of conjugate fibers having a first face and an opposite face, said conjugate fibers being composed of a lower melting component and a higher melting component, wherein a substantial proportion of the surfaces of said fibers comprises said lower melting component, said hydrophobic microfine fibers having a fiber diameter of up to 50 microns, said lower melting components of both layers of said conjugate fibers which lie on said first faces having been fuse bonded to opposite sides of said hydrophobic microfine fiber ply at a temperature below the melt temperature of said higher melting component of said conjugate fibers, so that the latter component retains its initial fiber-like integrity, said material having been treated with a water repellent.
In accordance with a further embodiment of the present invention, the layer of conjugate fibers may be blended with non-conjugate fusible fibers, with the proviso that the first face of the layer of conjugate fibers contains a plurality of conjugate fibers in the blend. The specific nature and melt temperatures of the non-conjugate portions of the blend are not critical since the conjugate-rich material in the first face of the layer which is fused to the hydrophobic microfine fiber ply insures good bonding features.
The present invention also includes a sterile package comprising a polymer blister sealed with a laminated material of the invention. In addition, the present invention includes a sterile package comprising a sealed envelope consisting of the laminated material of the invention.
The present invention also includes a process for preparing a water-impervious, smooth-surfaced, gas-permeable, bacterial barrier, repellent treated, laminated material comprising at least one layer of conjugate fibers, said layer of conjugate fibers having a first face and an opposite face, said conjugate fibers being composed of a low melting component and a higher melting component, wherein a substantial proportion of the surfaces of said conjugate fibers comprises said lower melting component, said lower melting component of said conjugate fibers which lie on said first face being fuse bonded to at least one hydrophobic ply of microfine fibers having a fiber diameter of up to 50 microns, said lower melting component of said conjugate fibers having been fuse bonded at a temperature below the melt temperature of said higher melting component of said conjugate fibers so that the latter component retains its initial fiber-like integrity, said process comprising forming an assembly of said ply of hydrophobic microfine fibers and at least one layer of said conjugate fibers placed adjacent to said ply of said hydrophobic microfine fibers; subjecting said assembly to smooth calendering at a temperature sufficient to fuse said lower melting component of said conjugate fibers which lie on said first face as well as the ply of the hydrophobic microfine fibers without fusing the higher melting component of said conjugate fibers, direct heat being applied to both outer surfaces of said assembly so that said surfaces are regular and the resultant material has good strength properties; cooling said assemply to resolidify said lower melting component of the conjugate fibers as well as said ply of said hydrophobic microfine fibers, whereby said conjugate fibers are firmly bonded to said hydrophobic microfine fiber structure without impairing the integrity of said higher melting component of said fibers, and treating said resultant laminated, material with a repellent, or utilizing a layer of conjugate fibers which has been pretreated with a repellent before forming said assembly of said ply of microfine fibers and said layer of conjugate fibers.
In accordance with an embodiment of the invention, there is provided a process for preparing a water-impervious, smooth-surfaced, gas-permeable, bacterial barrier, laminated material comprising at least one inner ply of hydrophobic microfine fibers sandwiched between two layers of conjugate fibers, each of said layers of conjugate fibers having a first face and an opposite face, said conjugate fibers being composed of a lower melting component and a higher melting component, wherein a substantial proportion of the surfaces of said fibers comprises said lower melting component, said ply of hydrophobic microfine fibers having a fiber diameter of up to 50 microns, said lower melting components of both layers of said conjugate fibers which lie on said first faces having been fuse bonded to said ply of hydrophobic microfine fibers at a temperature below the melt temperature of said higher melting component of said conjugate fibers, so that the latter component retains its initial fiber-like integrity, said material being resistant to steam sterilization, said process comprising forming an assembly of said ply of hydrophobic microfine fibers sandwiched between two layers of said conjugate fibers; subjecting said assembly to smooth calendering at a temperature sufficient to fuse said lower melting components of said conjugate fibers which lie on said first faces in both of said layers thereof as well as said ply of said hydrophobic microfine fibers without fusing the higher melting components of said conjugate fibers, direct heat being applied to both outer surfaces of said assembly so that said surfaces are regular and the resultant material has good strength properties; cooling said assembly to resolidify said lower melting components of the fibers as well as said ply of hydrophobic microfine fibers, whereby said fibers are firmly bonded to said hydrophobic microfine fibers without impairing the integrity of said higher melting component of said fibers and treating said resultant laminated material with a repellent, or utilizing layers of conjugate fibers which have been pretreated with a repellent before forming said assembly of said ply of microfine fibers and said two layers of conjugate fibers.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with the present invention, the hydrophobic microfine fiber ply may consist of any suitable thermoplastic polymer such as ethylene/propylene copolymer, polyester copolymer, low-density polyethylene, ethylene/vinyl acetate copolymer, polyethylene, polypropylene, chlorinated polyethylene, polyvinyl chloride, polyamide, high density polyethylene or linear low-density polyethylene.
Although continuous filaments of conjugate fibers may be employed, nevertheless the preferred conjugate fibers are textile length, that is, they are fibers having lengths of from one-quarter inch and preferably from one-half inch up to about three inches or more in length. Such conjugate fibers can be bi-component fibers such as the sheath/core of side-by-side bi-component fibers, wherein there is a lower melting component and a higher melting component, with a significant proportion and preferably a major proportion of the surface of the fibers being the lower melting component. Preferably, the lower melting component is a polyolefin, and most preferably, a polyethylene. In many cases the sheath/core, bi-component fibers are preferred, because they exhibit a better bonding efficiency than the side-by-side, bi-component fibers, and because in some cases the side-by-side, bi-component fibers may exhibit an excessive tendency to curl, crimp or shrink during the heat bonding step. Both concentric and eccentric sheath/core bi-component fibers can be used.
The nonwoven conjugate fiber layers of the present invention can have basis weights from about 0.25 to about 3.0 ounces per square yard. In the thermal bonding step, the lower melting component of the conjugate fiber is at least partially fused so that where the fused surface touches another conjugate fiber, welding or fusing together of the two fibers will occur. It is important in order to achieve the objects of the invention that the conjugate fibers remain fibers, i.e., that the higher melting component of the conjugate fibers not melt or shrink significantly and thereby become beads or the like. The layer of conjugate fibers may be oriented or random. However, oriented webs offer greater resistance to machine direction elongation, which is of benefit.
In accordance with a preferred embodiment of the invention, the hydrophobic microfine fiber ply comprises polypropylene or polyethylene. A preferred conjugate fiber comprises a polyethylene/polyester, sheath/core, bi-component fiber. Another preferred conjugate fiber comprises a polypropylene polyester, sheath/core, bicomponent fiber. Melt blowing is the preferred method of preparing the hydrophobic microfine fiber ply.
The preferred laminated material of the present invention is prepared by calendering between smooth heated rolls, direct heat having been applied to both outer surfaces of the material so that said surfaces are regular and the material has good strength properties. If the conjugate fibers have been initially oriented, the conjugate fiber webs will offer greater resistance to machine direction elongation.
The laminate of the present invention may be initially formed by passing a pre-bonded layer of conjugate fibers beneath a melt blown die which deposits said ply of microfine fibers on the surface of said layer of conjugate fibers.
Alternatively, the layer of conjugate fibers may be initially unbonded, and the ply of microfine fibers may be formed separately before being assembled with said layer of conjugate fibers.
Materials suitable for sterile-wraps should be able to protect the contents from airborne and waterborne bacteria contamination. These materials should also contain micropores to allow the contents to be sterilized by ethylene oxide and steam.
In accordance with the present invention, the laminates discussed above are treated with a water repellent to reduce fabric surface energy and voids between fibers. The repellent can be added by the "dip" and "nip" method before or after calendering. The "dip" and "nip" method is carried out by immersing the fabric in a bath of suitable repellent followed by passing the fabric through the nip between steel and rubber rollers to press off excess add-on. The water repellent may consist of a water repellent finish, a water repellent binder or a mixture of both. The water repellent finish, which is primarily utilized for its repellent effect, is far more repellent than the binder which, as the name implies, is utilized primarily for binding the fibers of the fabric and fabric plies together and to fill in the voids between the fibers.
The water repellent finish should comprise at least about 0.05% by weight of the untreated material. Further, the repellent binder should comprise at least about 1% (and preferably between about 1% and 25%) by weight of the unimpregnated material.
Examples of suitable water repellent finishes are wax emulsions, polyurethane emulsions, silicones and fluoro chemicals. Examples of suitable repellent finishes which may be utilized in accordance with the present invention are Aerotex 96B, sold by American Cyanamid (which comprises a polyurethane emulsion); Phobotex, sold by Ciba (consisting of a wax emulsion); FC 838 and FC 826, sold by Minnesota Mining and Manufacturing (consisting of a fluorochemical); and Milease F-14 and Milease F-31X, sold by ICI, (consisting of a fluorochemical).
The above repellent finishes, which improve the repellency of the laminate, are applied in the range of between 0.1 and 0.6% by weight, based on the weight of the untreated fabric. A preferred repellent finish, in accordance with the present invention is Milease F-14, a fluorochemical. Where the laminate of the present invention is to be utilized as a lid for a polymer blister, it is important that it should be able to be easily peeled from the blister, without delamination of fiberization of the laminate, and the repellent finish enables the laminate to be more easily peeled from the blister. However, no more than 5% by weight of the repellent finish should be used, since larger amounts tend to adversely affect the graphic printability on the outer surfaces of the laminate.
When the conjugate fiber side of the laminate is printed with a seal-coat system required for heat sealing the laminate to a formed polymer blister, then after the laminate is peeled from the blister there will be a tendency for fibers to be pulled off laminates. This problem is prevented, by providing the laminate with additional binder.
Suitable repellent binders which may be used in accordance with the present invention are: polybutyl acrylate, styrene-acrylic copolymer, acrylic vinyl chloride copolymer, ethylene-acrylic acid copolymer (preferably about 96% ethylene and about 4% acrylic acid), ethylene-vinyl acetate copolymer, ethylene-vinyl chloride copolymer, acrylic copolymer latex, styrene-butadiene latex, and vinyl chloride latex. Suitable repellent binders which may be utilized are Geon 580X83 and Geon 580X119, sold by Goodrich (consisting of vinylchloride latex); Emulsion E1497, and Emulsion E1847, sold by Rohm & Haas (consisting of an acrylic emulsion); and Rhoplex NW-1285, sold by Rohm & Haas (consisting of an acrylic emulsion); Airflex 120 and Airflex EVLC 453, sold by Air Products (consisting of ethylene vinyl chloride emulsions); Nacrylic 78-3990, sold by National Starch (consisting of an acrylic emulsion) and Primacor, sold by Dow Chemical (consisting of an ethylene/acrylic acid copolymer).
The methods for preparing the laminates of the present invention, are disclosed, in a general manner, in the Malaney U.S. Pat. No. 4,508,113, which is incorporated herein by reference.
In accordance with one method of the present invention, there is prepared a laminated material comprising a core of microfine fibers with facings of heat-fusible conjugate fibers on both faces of the core. In accordance with said method, a web of heat-fusible conjugate fibers is laid down (as from a card) onto an endless belt. Thereafter, a microfine fiber web which may be lightly prebonded, is then laid on top of the first web of conjugate fibers. Thereafter, the double layer web is passed under another station wherein a second web of heat-fusible conjugate fibers is laid on top (as from a card) so as to form a sandwich structure. Although the two conjugate fiber webs are preferably prepared from the cards, nevertheless, air-laid webs may also be used. Although the conjugate fiber webs are preferably fuse bonded in a subsequent step, said conjugate fiber webs may have been initially fuse bonded, in a prior step, before they are laid on either side of the microfine fiber web. The resulting triple layer web is then passed through a fusion unit to fuse the lower melting component of the conjugate fibers while maintaining the integrity of the higher melting component of these fibers as fibers, and to fuse the core layer of microfine fibers so as to securely bond the two conjugate fiber webs on either side of the microfine fiber web. When the multiple layer web emerges from the fusion unit, it cools to thereby form the laminate utilized in accordance with the present invention. After the triple layer laminate has cooled, the fused lower melting component of the conjugate fibers, solidifies and bonds then form where the surfaces touch other fibers. In the instance wherein the repellent is added after the laminate is prepared, any suitable means of fushion bonding may be used in the fusion unit such as by means of a conventional heated calender or by passing the assembly through an oven while the assembly is held between two porous belts under light pressure.
In the instance wherein the core of microfine fibers consist of polypropylene and the conjugate fibers comprise a polyethylene/polyethyleneterephthalate sheath/core bi-component fiber, the web temperature maintained in the fusion unit (whether the composite is belt or calender bonded) is preferably in the range of 135° C. to 145° C.
The exact temperatures employed in the fusion unit will depend upon the nature of the conjugate fiber used and the dwell time employed in the fusion unit. For instance, when the lower melting component of the conjugate fiber is polyethylene, the bonding temperature is usually from about 110° C. to about 150° C., and when the lower melting component is polyproplylene, the bonding temperature is usually from about 150° C. to about 170° C. Dwell times in the fusion unit will usually vary from about 0.01 seconds to about 15 seconds. In a modification of the above process, two layers of microfine fibers are used in contact with one another and only one layer of conjugated fibers is laminated to one side only of the microfine fiber layers. Otherwise the bonding procedure is the same as described above. Specific conditions under which the thermal bonding is achieved are illustrated in the examples below. The temperatures referred to are the temperatures to which the fibers are heated in order to achieve bonding. In order to achieve high speed operations, much higher temperatures with short exposure times can be used.
The examples below illustrate various aspects of the invention.
EXAMPLE I
A web of through-air bonded conjugate fibers (1.5 ounces per square yard) prepared by card webbing was fused into a fabrc in an oven. The conjugate fibers consist of high density polyethylene/polyethyleneterephthalate sheath/core bi-component fibers, the core being concentric. The high density polyethylene in the conjugate fibers has a softening range of 110°-125° C. and a melting point of about 132° C. The polyethyleneterephthalate core of the conjugate fibers has a softening range of 240°-260° C. and a melting point of about 265° C. The polyethylene comprises 50% of the conjugate fiber. Thereafter, a two ply web of polypropylene melt blown microfine fibers was laid on top of the conjugate fabric. The thickness of each melt blown web was 7 mil and each weighed 1 oz/yd 2 . The two ply melt blown web, after having been laid upon the conjugate fabric formed a triple layer web. The resultant triple layer web was bonded by a through-air belt bonder at 140° to 165° C. and then calendered on a smooth Ramisch calender at 130° C. This resulted in a well-bonded fabric. Thereafter the bonded triple layer fabric was treated by the "dip" and "nip" method with a mixture consisting of Primacor (a copolymer of ethylene and acrylic acid) sold by Dow Chemical Company, in order to impregnate the fabric with from 5 to 10% by weight, based on the untreated weight of the fabric, of the repellent binder, and with 0.02% by weight, based on the untreated weight of the fabric, of a fluorochemical repellent finish sold by ICI and known by the tradename Milease F-14.
The resultant triple layer fabric was very porous, but the hydrostatic head after repellent treatment was better than 100 cm. The hydrostatic head test, carried out in accordance with the basic hydrostatic pressure test AATCC TM #127-1977, involves subjecting a specimen to increasing water pressure while the surface is observed for leakage. The air permeability of the triple layer fabric according to the Gurley test was 4 seconds. This compares to a Gurley test reading for Tyvek of 23 seconds, and a Gurley test reading for paper of between 75 and 300 seconds. The Gurley test measures the amount of time required, under specified, conditions, for 100 cc's of air to permeate through a test sample.
EXAMPLE 2
Example 1 is repeated with the following modifications: One ply of polypropylene melt blown fibers (1.0 oz/yd 2 ) extruded from two separate dies, is laminated to one ply, only of the through-air bonded conjugate fabric (1.5 oz/yd 2 ). Otherwise, the bonding procedure is the same as that carried out in connection with Example 1 and, in addition, the laminate is treated with Primacor repellent binder and Milease F-14 repellent finish in a ratio of 30:1.
In each of the above examples, the thickness of each polypropylene melt blown web was approximately 5-10 mil and the thickness of the conjugate fabric was approximately 4-15 mil.
The product of Example 1 was found to possess good tensile strength and dimensional stability so that the laminate is suitable as a sterile packaging barrier, substantially impermeable to the passage of microorganisms in fluid but which is gas-permeable, smooth surfaced and highly printable.
TEST FOR BACTERIAL BARRIER PROPERTIES
The laminate prepared in accordance with Example 1 was subjected to air permeability tests in order to determine its bacterial barrier properties under positive atmospheric conditions. The laminate was subjected to the standard test procedure described in HIMA Test 78-4.11 No. 5 method June 1979 which is the protocol for determining the microbial barrier characteristics of packaging materials. This procedure is one which may be performed on any air permeable material to be used in packaging medical products. The principles of the test are as follows: Spores are introduced onto the surface of the test material under positive pressure. Spores that penetrate the sample are collected on a 0.45 micron filter, cultivated and counted. Inoculation level is determined by performing the tests without a sample in place and then recovering the spores. Percent efficiency of filtration can then be determined. This test is used to determine the relative filtering ability of packaging materials.
The following test results set forth the percentage penetration of spores through the product of Example 1. The spores utilized in the tests were B-stearothermophilus which were added to a nebulizer. Thereafter, the spores were introduced onto the surface of the test material under positive pressure.
TABLE 1______________________________________ Challenge Concentration Sample % Colony forming unitsExample 1 Penetration (CFUs)______________________________________Test 1 0.05 10.sup.5Test 2 0.18 10.sup.5______________________________________
It will be noted from the above Table 1 that at a spore challenge concentration of 10 5 spores per mil of water the sample percent penetration of the product of Example 1 was extremely low (0.05% for one test and 0.18% for another). This sample percent penetration is thus quite acceptable since the test was carried out under severe conditions. | A water-impervious, smooth-surfaced, gas-permeable, bacterial barrier, repellent treated, laminated material is described. A preferred embodiment comprises a ply of hydrophobic microfine fibers fuse bonded to a layer of conjugate fibers having a low melting sheath and a high melting core. The ply of hydrophobic microfine fibers is low melting. The sheaths of the conjugate fibers have been fuse bonded to the hydrophobic microfine fibers at a temperature below the melt temperature of the cores of the conjugate fibers so that the cores retain their initial fiber-like integrity. The laminated material is preferably impregnated with both a repellent binder and a repellent finish to secure good repellency, lamination and peelability. | 3 |
FIELD OF THE INVENTION
The present invention relates to containers and, more particularly, to a container for the preparation and/or dispensing of liquid cosmetic hair products.
BACKGROUND OF THE INVENTION
Typical cosmetic hair treatments involve preparing and applying a liquid color composition to hair. Hair color compositions ordinarily include a hair coloring ingredient which is carefully admixed in precise proportion with a developing agent. The developing agent and hair coloring ingredient then interact before being applied to the hair to be treated.
Hair color applications done by a salon professional involve formulas in which a hair coloring ingredient and a developing agent, usually hydrogen peroxide, must be admixed accurately to ensure a good hair color result. After they have been allowed to interact for a predetermined time period, the cosmetic product may be transferred to an appropriate dispenser for application to the hair being treated.
Many of the ingredients of cosmetic products, especially hair coloring compositions, are quite expensive. It is therefore desirable to utilize a mixing container in which precise amounts of the ingredients may be measured as they are combined. This avoids mistakes in their admixture and the necessity of adding an additional amount of one or more of the ingredients to effect the desired product formula. It allows the salon professional to mix less product per application and thereby avoid waste of expensive ingredients.
In dispensing or applying a cosmetic product such as a hair coloring composition, it is often important to ensure that the composition is applied in a manner which results in the desired effect. This may require careful placement of sometimes disproportionate amounts of composition. This is true, for example, whether one is streaking uniformly colored hair or attempting to make non-uniformly colored hair more uniform in appearance. As a result, it is important to carefully control where and how much cosmetic product is applied to the hair.
After application of the cosmetic product, the dispenser or the dispensing and mixing containers must normally be carefully cleaned to ensure that they are free of residue which might contaminate any subsequent cosmetic product placed in them. It is important in admixing dyes or tints to avoid unpleasant surprises to the hair being treated, particularly where a container which held a very dark dye is reused with a very light tint.
SUMMARY OF THE INVENTION
An object of the present invention is to create a container which allows the measured preparation of a cosmetic product, particularly a coloring composition for dyeing or bleaching hair.
Another object of the present invention is to create a container which will function as a dispenser of cosmetic product and allow careful control over where and how much of a cosmetic product, especially a coloring composition, is dispensed while treating hair.
Another object of the present invention is to create a container which is partially disposable. It is desired that at least most of the portion of the container which comes in contact with cosmetic product is replaceable, in order to facilitate the reuse of the container with different cosmetic products.
Still further objects of the present invention are the creation of a single container which can fulfil both of the foregoing functions and which will not require the careful and complete cleaning between uses which has normally been necessary.
In accordance with the present invention, there is provided a container for liquid cosmetic product including a housing composed of flexible sidewall means having an elongate central cavity, with the sidewall means having an opening at the anterior end of the housing. Disposed within the central cavity is a collapsible bag having an opening situated proximate to the anterior end of the housing. A cap is detachably affixed to the anterior end of the housing. The cap is adapted to hold the collapsible bag within the housing and has an aperture communicating with the bag opening.
The sidewall means of the housing are normally thin and may be composed of plastic or other flexible material. The container may have any number of sidewall means forming any elongate three-dimensional shape. However, it is preferred to utilize only one sidewall means, curved to provide a tubular housing.
By “flexible” according to the present invention, what is meant is that the housing sidewall means are relatively rigid and yet are deformable while under external pressure, such as squeezing, while rebounding to an undeformed shape when such pressure is relaxed. Because this flexibility effects the shape of the housing, it may also reduce the volume of its central cavity. Consequently, the application of external pressure on the container housing may be communicated by contact to the bag disposed within its central cavity.
The bag within the housing is collapsible. By “collapsible” according to the present invention, what is meant is that the bag and/or its walls are non-resilient and incapable of maintaining any particular shape, absent a supporting force. Like the housing, it may be composed of plastic, but usually its walls are much thinner in thickness.
A cosmetic product may be prepared by mixing its ingredients in the collapsible bag. Exertion of pressure on the housing causes it to flex radially inward, forcing the cosmetic product from the collapsing bag, through the cap aperture, for application to the hair being treated.
Relaxation of pressure controls this application. The housing rebounds to its original configuration. As the housing separates from the bag, the flow of product is reduced. Once the application of cosmetic product has been completed, the bag may be removed from the container and discarded. A new bag may be placed within the housing and the container is then ready for reuse.
In a preferred form of the present invention, the bag extends through the opening at the anterior end of the housing. The bag may have a circumferential lip which extends outwardly from the bag at the bag opening. It is especially desirable that the anterior end of the housing sidewall means forms a substantially circular edge. A similarly shaped lip may be pressed against the edge at the anterior end of the housing to ensure the optimal positioning of the bag within the central cavity of the housing.
In combination with the foregoing preferred embodiments of the present invention, it is desirable that the cap hold the bag in place by pressing the lip against the edge at the anterior end of the housing. One means by which this may be accomplished involves a cap comprising a substantially circular top and having a skirt disposed substantially perpendicularly from the perimeter of the top. The skirt may extend posteriorly of the edge of the anterior end of the housing. The skirt and anterior end of the housing may bear ridges, such as screw threads, adapted to detachably affix the cap to the housing. By screwing or otherwise locking the cap and housing temporarily together, the bag lip located between these elements is held firmly within the housing.
In a still further preferred embodiment of the present invention, a hollow or tubular dispensing member extends outwardly from, and communicates with, the cap aperture. This dispensing member may, for example, have a frusto-conical or other elongate shape in order to allow its penetration into a head of hair for application of hair coloring composition from its tip, directly to the hair roots.
The dispensing member and the associated cap aperture may be situated together anywhere on the cap. The dispensing member may extend radially or, more desirably, anteriorly from the cap. Most desirably, it is located acentric to the cap top. This enhances the ability to precisely direct application of the coloring composition to the desired location in the hair. This location also facilitates dispensing all the composition from the bag.
As previously described, there must be an opening at the anterior end of the housing. The sidewall means of the housing may similarly terminate at its posterior end, leaving a second opening through which the enclosed bag is exposed to the atmosphere. In this embodiment, the edge of the posterior end, like that at the opposite or anterior end of the housing, is desirably substantially circular. Thus, it may lie in a plane essentially perpendicular to the axis along which the container is elongated.
Alternatively, the posterior end of the housing may be sealed, thereby enclosing the bag. In this preferred embodiment, there may be a base spanning the sidewall means. Again, the plane of the base is desirably essentially perpendicular to the axis along which the container is elongated. Such a base provides a secure seating means for the container when it is not in use.
This alternative embodiment is also preferred because it has been discovered that such a base affords greater control over the dispensing of cosmetic product. Sealing off the posterior end of the housing from the atmosphere does not substantially effect the dispensing of cosmetic product while pressure is being applied to the housing sidewall means. However, when pressure is relaxed and the housing rebounds to an undeformed shape, air is drawn in through the dispensing means and/or cap aperture. This immediately reverses the flow of cosmetic product being dispensed. Consequently, it ensures against accidental over treatment of portions of hair.
In another preferred embodiment of the present invention, both the uncollapsed bag and the housing are substantially cylindrical in shape. Further, they are essentially contiguous or similarly sized so that the uncollapsed bag fits snugly within the central cavity of the housing.
Especially when these elements of the present invention have this preferred configuration, it is desirable that the sidewall means and bag are each composed of translucent or, even more desirably, transparent material. In this embodiment, the housing may bear graduated markings. Such markings may be adapted to measure the volume of liquid cosmetic product within the uncollapsed bag. This enhances the ability to precisely combine the amounts of hair coloring composition ingredients necessary for any given formula.
Other features and advantages of the present invention will become readily apparent from the following detailed description, appended drawings and accompanying Claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of this invention, a nonlimiting embodiment thereof will now be described with reference to the attached drawings wherein:
FIG. 1 depicts an assembled embodiment of the present invention.
FIG. 2 is a lengthwise cross-section through the container embodiment of FIG. 1 along line 2 — 2 .
FIG. 3 is an exploded elevation view of the container embodiment of FIG. 1 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The container 1 of the present invention shown in the exterior view of FIG. 1 has an elongate cylindrical housing 2 made of transparent plastic, for example polyethylene or polypropylene. Detachably affixed to the anterior end of the housing is the cap 12 . The cap is adapted to hold the collapsible bag (not shown) in the proper position within the housing 2 .
As shown in the cross-sectional view of FIG. 2, the container 1 is composed of the flexible housing 2 , the collapsible bag 9 and the cap 12 . Each is shown in its normal or unpressured orientation.
The collapsible bag 9 comprises the main receptacle for mixing and/or holding the liquid cosmetic product (not shown). It is depicted as being a thin liner which is essentially contiguous with the housing sidewall means 3 . The bag has a circumferential lip 11 which extends radially outwardly from the bag opening.
The housing 2 is composed of sidewall means 3 , here depicted as being tubular in shape. A base 18 , formed by molding the sidewall material across these means, seals the posterior end of the container. An elongate central cavity 4 , largely occupied by the previously described bag 9 , is enclosed within the sidewall means and this base. In this embodiment, the bag lip 11 is shown resting within the housing opening defined by the edge 6 at the anterior end of the sidewall means 3 .
The housing sidewall means 3 are thin so as to flex radially inward upon exertion of pressure such as occurs when squeezed in the operator's hand. Under such pressure, the volumes of the elongated central cavity 4 and the bag 9 disposed within it are correspondingly reduced. This forces the liquid cosmetic product (not shown) within the bag 9 out the bag and through the cap 12 .
The cap 12 is here shown as being composed of a substantially circular top 14 , having a skirt 15 disposed substantially perpendicularly from its perimeter and extending posteriorly of the anterior edge 6 of the housing.
The cap 12 is shown as being detachably affixed to the housing 2 by means of ridges 7 and 16 , correspondingly located on the contiguous surfaces of the housing sidewall means 3 and cap skirt 15 . These ridges 7 and 16 allow the cap 12 and housing 2 to be screwed snugly together. Moreover, as shown in this embodiment, the bag lip 11 lies between the anterior housing edge 6 and the cap top 14 . Consequently this same action also holds the bag 9 firmly in its appropriate position.
Also shown in this embodiment is an optional dispensing member 17 . A hollow conduit running the length of tubular dispensing member 17 communicates with the cap aperture 13 and extends to cap tip 19 . Consequently, liquid cosmetic product forced out of the bag 9 by pressure on the housing sidewall means 3 passes through the length of this hollow member and may be precisely dispensed from tip 19 to the desired location on an individuals hair.
As shown in the exploded view of FIG. 3, each of the three essential elements of this invention—the housing 2 , the bag 9 and the cap 12 —are easily separable from the others. This facilitates disposal and substitution of a new bag for reuse with the remaining elements whenever a new cosmetic product is to be mixed and/or dispensed.
The disposable bag 9 is shown in the normal, expanded shape it would exhibit if filled with liquid cosmetic product (not shown). This is largely the same shape as that of the tubular sidewall means 3 of the housing 2 . At the opening 10 of the bag 9 , there is depicted the circumferential lip 11 which extends radically outwardly and, in conjunction with the cap 12 and anterior housing edge 6 , allows the bag to be held in appropriate position within the container.
The housing 2 is here shown to be composed of an essentially tubular sidewall means 3 . At the anterior end of the sidewall means are shown ridges 7 for affixing the housing to the cap 12 as well as the substantially circular edge 6 , surrounding the housing opening 5 , upon which the bag lip 11 may rest.
Also depicted on the housing 2 are graduated markings 8 . They are adapted to measure the volume(s) of liquid ingredients added to the bag 9 within the housing. Such markings facilitate the correct and precise admixture of the appropriate ingredients of any particular cosmetic product.
The cap 12 is shown as comprising a skirt 15 , adapted to extend over the anterior end of the housing 2 for afixture thereto, and cap top 14 having a dispensing member 17 extending therefrom. The cap aperture (not shown) communicates with the bag opening 10 and the dispensing member to permit application of cosmetic product to the hair from the tip 19 of that member.
It is to be understood that the provided illustrative examples are by no means exhaustive of the many possible uses of the invention. From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirt and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions. For example, the artisan could construct the present container other suitable geometric shapes. It is to be understood therefore that the present invention is not limited to the sole embodiment described above, but encompasses any and all embodiments within the scope of the following claims. | This invention relates to a container suitable for preparing and dispensing a liquid cosmetic product, particularly a product for dyeing or bleaching hair. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates generally to a downhole rod pump assembly, and more particularly, but not by way of limitation, to such an assembly adapted for safe use in steamflood operations.
A typical downhole rod pump is seated in a seating nipple within a production tubing string, and the lower end of the production tubing string is always open to the well bore so that fluid from the well is drawn into the pump and then pumped from the pump upward through the production tubing string upon reciprocable motion of a string of sucker rods connected between the rod pump and a walking beam pump jack located at the ground surface.
A safety problem is encountered with typical prior art rod pump apparatus when such apparatus are used in a well producing high temperature fluids. For example, in some steamflood operations, the fluid from the well is at a temperature in a range from 90° F. to 310° F. when it reaches the ground surface.
If the rod pump fails, it is sometimes very difficult or impossible to pull the sucker rods and the rod pump out of the well because of the hot fluid flow, or the pulling unit crew may be subject to severe burns from the hot fluid if they do attempt to pull the sucker rods and the rod pump from the well.
Very often, such a well cannot be killed with high density drilling mud in order to allow the rods and pump to be pulled.
The present invention overcomes these problems by providing a production tubing extension extending below the seating nipple and having a spring loaded flapper valve on the lower end of the production tubing extension. The rod pump is provided with a dip tube having a sufficient length such that when the rod pump is seated in the seating nipple, the dip tube engages the flapper valve and holds the flapper valve open. A polished rod at the upper end of the sucker rod string is provided with an extended length so that the rod pump may be positioned at a sufficient distance above the seating nipple so that the dip tube is above the flapper valve allowing the flapper valve to close, while the polished rod is still sealed within a stuffing box connected to an upper end of the production tubing string.
It is, therefore, a general object of the present invention to provide an improved downhole rod pump assembly.
Another object of the present invention is the provision of a downhole rod pump assembly including a spring loaded flapper valve attached to a lower end of an extension of the production tubing.
Yet another object of the present invention is the provision of a downhole pump assembly having a flapper valve on the production tubing, a dip tube connected to a lower end of the rod pump for opening the flapper valve, and an extended length polished rod for allowing the polished rod to be sealed within a stuffing box when the dip tube is at a position above the flapper valve.
Still another object of the present invention is the provision of improved methods of installing and removing a rod pump from a well.
Other and further objects, features and advantages of the present invention will be readily apparent to those skilled in the art upon a reading of the following disclosure when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic elevation section view of a rod pump being lowered into or removed from a well. The rod pump is in a position above the seating nipple with the lower end of the dip tube above the flapper valve. The polished rod is sealed within the stuffing box.
FIG. 2 is a view similar to FIG. 1 showing the rod pump lowered into seating engagement with the seating nipple and showing the dip tube having engaged and opened the flapper valve on the lower end of the production tubing extension.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, a well 10 defined by an inner bore of well casing 12 extends from a ground surface 14 downward and intersets a subterranean formation 16. A plurality of perforations 18 communicate the subterranean formation 16 with the interior of well 10.
A production tubing string 20 is suspended in the well 10 and a packer means 22 seals an annulus 24 between the production tubing string 20 and the well 10.
Connected to a lower end of production tubing string 20 is a seating nipple 26 which may generally be described as a seating means for seating a downhole rod pump 28.
A tubing collar 30 connected a production tubing extension 32 to the seating nipple 26. Connected to a lower end of production tubing extension 32 is a disc-shaped flapper valve 34 which is connected to production tubing extension 32 by a resilient spring means 36. A metal-to-metal seal is provided between flapper valve 34 and the lower end of production tubing extension 32.
Flapper valve 34 provides a valve means for selectively opening and closing the production tubing extension 32 to thereby communicate an interior 38 of production tubing string 20 with and to isolate said interior 28 of production tubing string 20 from the well 10.
Connected to a upper end of production tubing string 20 is a stuffing box 40.
Disposed in stuffing box 40 are a plurality of annular packing members 42 and a packing gland 44 for compressing the packing elements 42 to seal the packing elements 42 around a polished rod 46. Below the packing elements 42 an outlet 48 of stuffing box 40 is attached to a control valve 50, the other end of which is connected to a production line 52.
Connected to a lower end of polished rod 46 at a coupling 54 is a string of sucker rods 56 all of which are connected by couplings 58. A lower end of the string of sucker rods is connected to the upper end 60 of rod pump 28 for actuating the rod pump 28 by reciprocating motion of a plunger therein as is well known to those skilled in the art.
The rod pump means 28 is adapted at 62 to be seated in a seat 64 of seating nipple 26, also in a manner well known to those skilled in the art.
Extending downward from a lower end 66 of rod pump 28 is a dip tube 68 which is a tubular member having a plurality of perforations 70 therein and an open lower end 72.
The dip tube 68 may generally be referred to as a valve actuating means 68 operably associated with the rod pump 28 for opening the flapper valve means 34 when the rod pump 28 is seated in the seating means 64 of seating nipple 26 and for closing the flapper valve 34 when the rod pump 28 is unseated from the seating means 64.
For example, in FIG. 1, the rod pump is illustrated in an unseated position wherein the lower end 72 of dip tube 68 is held above flapper valve 34 so that flapper valve 34 is in a closed position.
The polished rod 46 has a length sufficient such that a lower portion of the polished rod may be sealingly received within the stuffing box 40 as shown in FIG. 1 when the rod pump 28 is in an unseated position and the valve means 34 is in a closed position, also as shown in FIG. 1.
The dip tube 68 may also be described as a rigid member extending downward from the lower end 66 of rod pump 28 and having a length such that when the rod pump 28 is seated in the seating means 64, as shown in FIG. 2, the rigid member 68 extends below the lower end of tubing extension means 32 as shown in FIG. 2, thereby holding the flapper valve 34 open.
As can be seen in FIG. 1, a combined length of the string of sucker rods 56 below coupling 54, the rod pump 28, and the dip tube 68 is less than a distance between a lowermost one of seals 42 of stuffing box 40 and the lower end of production tubing extension 32. This allows the lower portion of the polished rod 46 to be sealed within stuffing box 40 while the rod pump 28 is in a position above seating nipple 26 such that the lower end 72 of dip tube 68 is above flapper valve 34 allowing flapper valve 34 to be in a closed position as shown in FIG. 1.
The methods of installing and removing the rod pump 28 into and from the well 10 are as follows.
The production tubing string 20 with seating nipple 26 and a production tubing extension 32 must be provided, with a flapper valve 34 on a lower end of the production tubing extension 32.
The rod pump 28 is then attached to a lower end of the string of sucker rods 56. It will be understood that the sucker rods 56 are assembled as the pump 28 is lowered into the well. At the upper end of the string of sucker rods 56, a polished rod 46 is attached. Before lowering the rod pump 28 into the well, the dip tube 68 is attached to the lower end of the rod pump.
Then the sucker rod string, rod pump 28 and dip tube 68 are lowered into the production tubing string 20 to a first position as illustrated in FIG. 1 wherein the lower end 72 of dip tube 68 is above flapper valve 34.
Next, the packing elements 42 are sealed around polished rod 46 by tightening the packing gland 44. Then the polished rod 46 is driven further downward through the stuffing box 40 thereby pushing the flapper valve 34 open with the dip tube 68 and seating the rod pump 28 in the seating nipple 26 as shown in FIG. 2.
To subsequently remove the rod pump 28 from the well 10, the string of sucker rods 56 is raised a first distance to an orientation again such as that shown in FIG. 1, thereby unseating the rod pump 28 from the seating nipple 26 and then moving the dip tube 68 above flapper valve 34 allowing the flapper valve 34 to close. This is done while the polished rod 46 is still sealed within the stuffing box 40.
Once the flapper valve 34 is closed as shown in FIG. 1, it is then safe to break the seal of stuffing box 40 by loosening the packing gland 44 and removing it and the stuffing elements 42 so that the string of sucker rods 56 and the rod pump 28 may then be pulled out of the well 10.
Thus, it is seen that the apparatus and methods of the present invention readily achieve the ends and advantages mentioned as well as those inherent therein. While certain preferred embodiments of the invention have been illustrated for the purposes of the present disclosure, numerous changes in the arrangement and construction of parts and steps may be made by those skilled in the art, which changes are encompassed within the scope and spirit of the present invention as defined by the appended claims. | Apparatus and methods are provided for installing and removing a downhole rod pump form a well while preventing flow of fluids from the well through a production tubing string. | 4 |
This application is a continuation of application Ser. No. 08/575,560, filed Dec. 20, 1995, now abandoned.
FIELD OF THE INVENTION
The present invention relates to oil field operations for making up and breaking apart tubing joints and more specifically relates to a power tong which is longitudinally connectable to a pipe string and is suitable for operations on single or multiple string tubing operations.
BACKGROUND OF THE INVENTION
Tongs are used in oil field operations to grip and rotate joints of pipe to make up (screw together) or break apart (screw apart) the pipe. These operations typically require two tongs: a tong which is used to rotate the upper pipe; and a backup tong which is used to hold the lower pipe and prevent its rotation. The upper tong is commonly a power tong which has a mechanism to grip and rotate the pipe while the body or housing of the tong remains stationary.
Power tongs can be classified by various characteristics, one of which is whether the tong has an open or closed throat. . Closed-head tongs have a generally annular shaped ring which fits around the pipe in order to grip and rotate it. Closed-head tongs are typically capable of transmitting more torque to a pipe, but prior art closed-head tongs typically are not easily placed on the pipe from a position lateral to the pipe. Some prior art closed-head tongs cannot be moved laterally onto a pipe at all. Prior art closed-head tongs are also typically large enough and cannot easily be used with dual tubing strings without splaying the tubing strings to allow the tong to be placed on either of the strings.
Open-throat tongs, on the other hand, are much easier to move laterally onto a pipe. Open-throat tongs, however, generally cannot develop the torque of a closed-head tong and are susceptible to spreading of the open throat portion of the gripping member in high torque situations.
The prior art thus teaches that the design of a power tong involves a choice between the advantages of a closed-head tong (i.e., high radial gripping force capability) and the advantages of an open-throat tong (i.e., the ease with which the tong is moved laterally onto and off of pipes). If a closed-head design was chosen, it was accompanied by the disadvantage of not being able to move it laterally onto pipes. If the open-throat was chosen, it was accompanied by the disadvantage of reduced radial gripping force.
SUMMARY OF THE INVENTION
The present invention combines the advantages of a closed-head tong (high radial gripping force capability) with the advantages of an open-throat tong (ease of lateral movement onto the pipe) without suffering form the disadvantages of either. This is accomplished by utilizing a multi-sectioned gripping ring to allow ease of lateral positioning of the tong on the pipe string while still developing the high radial clamping forces and torques which are characteristic of closed-head tongs.
The gripping ring of the invention has circumferentially slidable die carriers which hold radially movable dies. As the housing rotates, the die carriers slide circumferentially, and cams in the housing and on the dies force the dies radially inward to grip the pipe. Return of the die carriers to their rest positions with respect to the housing allows the dies to move radially outward from the pipe, thereby releasing it. The invention further contains an indexing mechanism to ensure the alignment of the housing and slidable die carriers so that the housing and gripping mechanism can be easily opened for positioning on the pipe or taking the invention off the pipe.
It is therefore an object of the invention to provide a power tong which provides the high clamping force necessary for the high torque output of a closed-head tong while allowing the ease of use of an open throat tong by utilizing a hinged housing which completely surrounds the pipe in the closed position, but allows the tong to engage the pipe by moving the tong in its open position laterally onto the pipe.
It is another object of the invention to provide a power tong which is small enough to be easily used with dual pipe strings while still developing sufficient torque to make up or break apart pipe joints.
It is another object of the invention to provide an improved bi-directional gripping mechanism which also ensures synchronous movement of dies and die carriers in a power tong.
It is yet another object of the invention to provide a multi-sectioned, gripping ring which has an indexing mechanism to insure alignment of the die carriers and section members so that the gripping ring can be easily opened.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a power tong showing the inventive gripping ring in a closed position.
FIG. 2 is a perspective view of a power tong showing the inventive gripping ring in an open position.
FIG. 3 is a partial cut-away plan view of the inventive gripping ring in the open position.
FIG. 4 is a partial cut-away plan view of the inventive gripping ring in the closed position, with die carriers in their indexed positions.
FIG. 5 is a partial cut-away plan view of the inventive gripping ring in the closed position with the die carriers offset from their indexed positions, and the dies engaging the pipe.
FIG. 6 is an elevation view of the center section of the inventive gripping ring.
FIG. 7 is a cross-section of the gripping ring section of FIG. 6.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 and 2, the inventive gripping ring 3 is shown. Power tong 1 utilizes gripping ring 3 with tong body 5 to grip and rotate a pipe section (not shown). Backup tong 2 holds the pipe coupling, which is mated to the pipe, stationary while the pipe is rotated by power tong 1. Because of the design of the inventive gripping ring 3, the annular thickness of the gripping ring is small enough that the power tong can be used on one of two adjacent pipe strings in a multiple-string operation without having to splay two pipes apart. Nevertheless, the inventive tong can still develop the necessary gripping force and torque to make up or break apart the pipe sections and pipe couplings.
In the closed position, the housing of gripping ring 3 forms a cylindrical or annular shape. The housing comprises housing sections 11, 12, 13. The gripping ring 3 is mounted on top of tong body 5 which houses the drive mechanism (not shown) which rotates gripping ring 3. The drive mechanism is enclosed within the body which is formed by upper plate 31, lower plate 32, and side walls 35 and 36. The drive mechanism is powered by motor 34 and is operated by controls 38, 39 and 40.
Power tong 1 is connected to frame 42. Frame 42 is in turn connected to torque post 43 which is connected to backup tong 2 via swing arms 47, 48. When gripping ring 3 is rotated to engage a pipe, the torque which is transferred to the power tong is transferred through the torque post to the backup tong and finally to the pipe coupling, thereby causing the pipe, rather than the power tong, to rotate. A pair of structural arms 50, 51 having handles 52, 53 are connected to the lower end of torque post 43 to assist the tong operator in positioning the power tong and backup tong.
Because the inventive power tong is adapted for use in multiple pipe string operations, it is ideally used in conjunction with a backup tong which is also suitable for use with multiple pipe strings. Such a backup tong is shown in FIGS. 1 and 2. The backup tong shown in these figures generally comprises upper plate 58, lower plate 59, jaw members 60 and 61, and gripping members 62 and 63. The backup tong is connected to torque post 43 by swinging arms 47 and 48 so that the backup tong can move laterally with respect to the torque post, but cannot rotate with respect to the torque post.
The backup tong 2 has an actuator disposed between upper plate 58 and lower plate 59 which forces the ends of jaw members 60 and 61 outward. Jaw members 60 and 61 pivot around pivot bolts 70 and 71 causing gripping members 62 and 63 to move closer to each other. When gripping members 62 and 63 are positioned around a pipe, dies 68 and 69 are brought into contact with the pipe to grasp it and hold it stationary. As dies 68 and 69 begin to engage the pipe, gripping members 62 and 63 are allowed to pivot about pivot connections 64 and 65. This allows dies 68 and 69 to move somewhat so that the curved faces of the dies can fully engage the pipe even when it is not perfectly centered between gripping members 62 and 63 and on the center line of backup tong 2.
Referring to FIGS. 3-5, the preferred embodiment of the gripping ring 3 is shown. A gripping ring housing is formed by housing sections 11, 12, 13. In the closed position, the housing sections 11-13 have a generally cylindrical shape with a coaxial opening therethrough, into which a pipe fits. The gripping ring may also be described as annular in shape. The central housing section 12 is connected to swinging housing sections 11, 13 by hinges 14. The hinges allow the sections to open or swing outward so that a pipe can be placed between the sections and the sections thereafter closed around the pipe. The open gripping ring is shown in FIGS. 2 and 3, while the closed gripping ring is shown in FIGS. 1, 4 and 5. In the closed position, outer sections 11 and 13 are latched together by a locking latch mechanism.
While the entire latch mechanism is not shown in the Figures, it can be seen in FIGS. 4 and 5 that the latch holds the swinging housing sections 11, 13 together by moving a pair of locking bars 26, 27 through a pair of apertures 28, 29 in the swinging housing sections. Each of the apertures 28, 29 extends through one of the housing sections 11, 13 when gripping ring 3 is in the open position. When ring 3 is in the closed position, each aperture 28, 29 extends through a housing section 11,13 and both extend through latching member 25. When the housing sections are in the closed position, the apertures are aligned through the housing sections and the latching member so that locking bars 26, 27 can be placed in apertures 28, 29 to hold the non-hinged ends of the housing sections together, thereby holding them in the closed position.
A die carrier 15 is slidably mounted on the inner face of each housing section 11, 12, 13. The die carriers 15 cover angular sections equal to those of housing sections 11, 12 13. Thus, the edges of the die carriers 15 are radially aligned with the corresponding edges of housing sections 11, 12, 13 when the gripping ring is in its indexed position. See FIG. 4. When the housing sections are in closed position, the die carriers 15 slide circumferentially along the face of their corresponding housing sections so that the die carriers overlap with adjacent housing sections (see especially FIG. 5).
Referring to FIGS. 3 and 6, dies 16 are mounted within the die carriers 15. Each die 16 is mounted within an opening in the die carrier 15 so that it may move radially, either toward or away from its respective housing section. Dies 16 are restricted to radial movement by the walls of the openings through die carriers 15, as well as by pins 20 which fit into slots 19. The radial travel of each die 16 is limited by pins 20 which extend from die 16 into slots 19 in die carrier 15.
Dies 16 have two curved faces, one which is concave and one which is generally convex. The concave faces of the dies are gripping faces and have approximately the same curvature as the pipe to be gripped. The gripping faces of the dies have ridges, or teeth, which run parallel to the axis of the annular gripping ring to reduce slippage between the dies and the pipe as the gripping ring rotates the pipe. Any suitable type of texturing or knurling may be used on the concave face of the dies to enhance the grip of the dies on the pipe.
On the opposite, convex side of dies 16 are smooth camming surfaces 17. A cam 24 is mounted in each housing section behind die 16. The camming surface 17 of die 16 faces cam 24. The surface of cam 24 which faces die 16 is normally in contact with the generally convex camming surface 17. The contacting surfaces of cam 24 and die 16 are shaped so that, when the die 16 and die carrier 15 are in their indexed positions (i.e., centrally located on the housing section), the die 16 can move radially outward, toward the housing section and away from the pipe as shown in FIG. 4. When die 16 and die carrier 15 are offset from their indexed, central location with respect to the housing section, the cam 24 presses against the outer portion of camming surface 17 of die 16, forcing die 16 to move radially inward, away from the housing section and toward the pipe as shown in FIG. 5.
In the preferred embodiment, the camming surface 17 of die 16 is symmetric, so that the die is forced to move radially inward the same distance, whether the die and die carrier are moved a given amount clockwise or that same amount counterclockwise from the indexed position with respect to the housing section. The die is slightly thinner at its center (allowing the die in its central, indexed position to rest radially outward from and out of contact with the pipe) and its thickness gradually increases as the distance from its center increases (forcing the die radially inward as the thicker portion of the die is moved into a position between cam 24 and the pipe).
The dies 16 of the preferred embodiment are removable by sliding the die carrier 15 out of its respective housing section and then sliding the die out of the convex side of the die carrier. The dies can thus be easily exchanged with a set having a different thickness or curvature to more exactly fit different sizes of pipe (although the invention is inherently capable of gripping pipes of various diameters).
Referring to FIG. 7, each housing section has a generally C-shaped cross-section into which die carrier 15 fits. Die carrier 15 has a tongue or ridge 30 along its upper edge which fits into a corresponding groove 31 at the top of the housing section's C-shape. The die carrier 15 also has a ridge 30 along its bottom edge which fits into a corresponding groove in the bottom of the housing section's C-shape. Thus, die carrier 15 is prevented from moving radially, but is allowed to slide circumferentially in the housing section. As explained above, the die carriers can be slid out of the housing sections when the housing is in the open position so that dies or even the die carriers can be replaced. In the preferred embodiment, ridges 30 have beveled corners so that the die carriers are easily inserted into grooves 31.
The housing sections of the preferred embodiment also have a pin 21 retractably mounted therein for use as an indexing mechanism. The die carrier 1 has a corresponding indentation 22 so that, when the die carrier is centered in its location within the housing section, pin 21 is urged into indentation 22 by spring 23. This indexing mechanism overcomes a problem resulting from the overlap of die carriers with adjacent housing sections as shown on FIG. 5. This overlap causes interference between the die carriers and housing sections so that movement of the housing sections from the closed position to the open position is impaired or even prevented. Even though the tong operator cannot see the die carriers to align them with the housing sections, the indexing mechanism allows the tong operator to ensure their alignment before opening the housing sections and possibly damaging the gripping ring.
A tong utilizing the inventive gripping ring is operated as follows. First, the closed gripping ring is rotated until the die carriers are in their indexed positions. The housing sections are then moved to the open position and the tong is positioned laterally so that a pipe is disposed within the throat of the open gripping ring. The housing sections of the gripping ring are then closed over the pipe and latched in the closed position. A brake band (not shown in the drawings) applies friction to the die carriers to prevent them from moving until the dies are firmly engaged with the pipe. As the gripping ring is rotated from the central, indexed position, the die carriers are held stationary by an external brake band while the housing sections and cams rotate. The housing sections thus move circumferentially with respect to the die carriers. As the housing sections move relative to the die carriers, cam 24 and cam surface 17 of die 16 engage and force the dies inward toward the pipe. As the dies 16 engage the pipe, radial movement of the dies is stopped and the die carriers 15 are prevented from further motion relative to the housing sections (i.e., they can no longer stay stationary while the housing rotates). The rotational force applied by the housing to the die carriers at that point overcomes the frictional force of the brake band, causing the die carrier and the pipe to rotate.
From the foregoing disclosure, many modifications to the invention will be apparent to persons skilled in the art without departing from the scope of the invention. The embodiments described above are exemplary rather than exhaustive and such modifications are contemplated by the invention. | A multi-sectioned, bidirectional gripping ring for a closed-head power tong is disclosed of the inventive gripping ring have an open position in which a pipe may be placed within or removed from the gripping ring and a closed position in which the gripping ring completely encircles the pipe. The inventive gripping ring uses radially moveable dies in circumferentially moveable die carriers to grip the pipe. The dies are synchronously moved in the radial direction to grip or release the pipe by changing their circumferential position with respect to the cams in the gripping ring housing. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a salad bar unit of the type used for storing and dispensing hot and cold food items, and which has an overhead refrigerated cabinet that stores beverages and other items.
2. Description of the Prior Art
The demand for various prepared cold food items such as fruit, vegetables, desserts and other salad items, as well as precooked hot items such as wings, and ribs, has increased considerably due to the increase in the number of working persons, and the decrease in available time for home meal preparation. As a result refrigerated salad bars and separate hot food bars are now present in many markets. Persons selecting food items often purchase soda, fruit juice and other beverages that compliment the salad or hot bar selection. It has been observed that many purchases are impulse purchases, and that customers are influenced in their purchases by the display and ready availability of merchandise. Accordingly it is desirable to be able to present the consumer with a wide variety of hot and cold food items, and simultaneously to provide beverages that compliment the food items. Various salad bar constructions have been proposed such as shown in the following U.S. Pat. No. Design 92,122 to Weiss, U.S. Pat. No. Design 220,140 to Perl, U.S. Pat. No. Design 288,040 to LeBlanc, U.S. Pat. No. Design 326,024 to Boyd et. al., U.S. Pat. No. 2,900,045 to Conklin et. al., and U.S. Pat. No. 4,572,598 to Moore, Jr. No satisfactory apparatus has been previously available. The present unit offers the consumer in one location, a variety of hot and cold food items, and a selection of refrigerated beverages and other items in a self contained unit that can be easily installed, stocked and maintained.
SUMMARY OF THE INVENTION
This invention relates to a salad bar unit with a refrigerated overhead storage cabinet having stalls therein, which unit presents a variety of hot and cold food items at waist level, and presents refrigerated beverages and other items in a cabinet above the food items, all in one self contained unit.
The principal object of the invention is to provide a salad bar and refrigerated overhead storage cabinet in a self contained unit.
A further object of the invention is to provide a unit of the character aforesaid that is easy to install, stock and maintain.
A further object of the invention is to provide a unit of the character aforesaid which appeals to impulse buyers of food and beverage items.
A further object of the invention is to provide a unit of the character aforesaid that provides quick and easy access to both food and beverage items.
A further object of the invention is to provide a unit that can be easily serviced, and is efficient in operation.
Other objects and advantageous features of the invention will be apparent from the description and claims.
DESCRIPTION OF THE DRAWINGS
The nature and characteristic features of the invention will be more readily understood from the following description taken in connection with the accompanying drawings forming part hereof in which:
FIG. 1 is a side elevational view of the salad bar with refrigerated overhead storage cabinet of the invention;
FIG. 2 is a vertical sectional view taken approximately on the line 2--2 of FIG. 1;
FIG. 3 is an end elevational view of the invention;
FIG. 4 is a top plan view of the equipment portion of the invention;
FIG. 5 is a top plan view, enlarged, of the hot and cold food salad bar portion of the invention, and
FIG. 6 is a view similar to FIG. 4 illustrating the electrical wiring of the equipment portion of the invention.
It should, of course, be understood that the description and drawings herein are merely illustrative, and that various modifications and changes can be made in the structure disclosed without departing from the spirit of the invention.
Like numerals refer to like parts throughout the several views.
DESCRIPTION OF THE PREFERRED EMBODIMENT
When referring to the preferred embodiments, certain terminology will be utilized for the sake of clarity. Use of such terminology is intended to encompass not only the described embodiment, but also technical equivalents which operate and function in substantially the same way to bring about the same result.
Referring now more particularly to FIGS. 1-3 and 5 of the drawings, one embodiment of the salad bar overhead refrigerated unit 10 of the invention is illustrated.
The unit 10 comprises a salad bar 11 at waist height, with an overhead cabinet 12 thereabove and connected thereto, which is refrigerated, and which cabinet supports the mechanical refrigeration and electrical components of the unit, to be described.
The salad bar 11 is of rectangular configuration as seen from the top, with top wall 18, side walls 20 and 21, and end walls 22 and 23.
As shown in FIG. 5 the salad bar 11 at the left end wall 22, has a recessed area 25 in wall 18 which extends transversely thereacross between the side wall 20 and 21, and which is used to store empty salad containers and other accessories (not shown) which are to be used by the consumer.
To the right of area 25 is a cold storage area 26, which has a plate 27 recessed down from the top wall 18, wherein a plurality of containers 30, 31, 32, 33, 34 and 35 are provided, which are filled with the food items (not shown) to be selected by consumers. The area 26 is kept refrigerated by well known refrigeration equipment therebelow (not shown), which is connected to the mechanical equipment (to be described) carried on top of overhead cabinet 12.
To the right of area 26 an additional storage area 40 is provided, which is illustrated with eight openings 41 in plate 42, which can hold containers (not shown) for salad dressings. To the right of area 40, area 45 is provided, which includes recesses 46 for plastic ware (not shown), and recesses 47 for soup pots (not shown). Additional recesses 48 are also provided for other containers (not shown). To the right of area 45, area 50 is provided, which has hot well recesses 51 which are heated, and in which containers (not shown) holding food items to be kept hot can be placed. At least two heat lamps 55 are provided mounted to cabinet 12, and located over areas 45 and 50 to assist in maintaining the proper temperature in these areas. A sneeze shield 60 is provided which is mounted to the overhead cabinet 12, and extends around it over the salad bar 11. The sneeze shield 60 is preferably constructed of transparent safety glass, and is intended to protect the food items (not shown) from contamination by consumers.
The overhead cabinet 12 is attached to the salad bar 11 by columns 61, which can be hollow and constructed of stainless steel or other suitable material. The columns 61 support the cabinet 12, and carry electric and refrigeration lines therein (not shown) as desired. The cabinet 12 as seen from the top is of rectangular configuration similar to salad bar 11, but of lesser overall size. The upper or overhead cabinet 12 has a bottom wall 62, side walls 63, 64, end walls 65, 66 and top wall 67.
The interior space 68 between the walls, 62, 63, 64, 65, 66 and 67 is divided into a plurality of stalls 70, 71, 72 on each side, and stall 73 at one end, by channel members 74, which do not restrict air movement in the interior space 68 in cabinet 12.
The interior space 68 is refrigerated by the equipment carried on top of cabinet 12 (to be described), and preferably by circulating chilled air in the space 68.
The stalls 70, 71, 72 on each side are further divided in half, and a pair of doors 75 are provided at each of the open ends of the stalls, which are slidable in channels (not shown) carried in cabinet 12. Each of the doors 75 can be opened and closed to provide access to the particular stall desired. The stalls 70, 71 and 72 are provided with racks 76 and 77, which carry stacks of cartons or bottles 78 as shown in FIG. 2, and can be sloped downwardly to urge the bottles 78 to move toward the doors 75. A plurality of lights 79 are provided adjacent to the stalls 70, 71, 72 and 73 for illumination. Above the stalls 70, 71, 72 and 73 display panels 80 are provided in walls 63, 64, 65, and 66, which can carry logos that advertise and identify the brands of beverages and other items that are carried in the stalls 70, 71, 72 and 73.
Referring now to FIGS. 4 and 6, the refrigeration equipment and electric wiring for the unit 10 is illustrated.
The equipment includes a light switch 100 connected by wire 101 to a lighting ballast box 102, which has wires 103 connected thereto and to lighting fixture 104 and 105 in well known manner. A lighting junction box 106 is provided connected to lighting ballast box 102 by wire 107, and to a source of electrical power (not shown) by wire 108.
The refrigeration equipment includes a condensing unit 110, an evaporator unit 111, refrigeration lines 112, and a low pressure control 113, which is connected to a ceiling mounted junction box (not shown) by wire 114. A thermostat 115 is provided connected to the ceiling mounted junction box (not shown) by wire 116.
A defrost time clock 118 is provided connected to junction box (not shown) by wire 119. Condensing unit 110 is connected to junction box (not shown) by wire 120, and evaporator unit 111 is connected to junction box (not shown) by wire 121.
A pump down solenoid 125 of well known type, is provided to supply refrigerant (not shown) down to the salad bar for cooling. Additionally a fan is provided (not shown) inside cabinet 12 to circulate chilled air from the evaporator units 111 to the space 68 inside cabinet 12.
A hollow conduit (not shown) is provided, which carries the electric lines 108, 114, 116, 119, 120 and 121 to the junction box (not shown), which is preferably mounted on the ceiling (not shown) above the cabinet 12.
It will thus be seen that a salad bar unit with refrigerated overhead storage cabinet has been provided with which the objects of the invention are achieved. | A salad bar unit with an overhead refrigerated storage cabinet wherein the salad bar at waist height contains a variety of containers, some of which are cooled and some of which are hot, and which are used to hold various food items to be selected by consumers. The unit is provided with an overhead cabinet that is divided into a plurality of independent refrigerated stalls open at one end, with transparent dividers, and having interior racks carrying containers of soda, milk, fruit juice and other items to which access is available through transparent doors that close off the open ends of the stalls. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a domestic electric appliance with an electrodialytic water purifier, and particularly, to a humidifier with an electrodialytic water purifier that removes dissolved matter, which may otherwise settle and cause white spots on household effects such as furniture, from humidifying water and produces an electric field for preventing fur and bacteria from growing in water stored in the humidifier.
2. Description of the Prior Art
Domestic electric appliances such as a humidifier usually use tap water, which comes from rivers, lakes, ponds, dams, reservoirs, etc. Raw water from rivers, etc., is purified at a purification plant. In the purification plant, the raw water is passed through sedimentation and filter basins to remove suspended matter, bacteria, iron, manganese, and organic components, which may cause smells and unpleasantness, from the water. The cleaned water is still biologically active to contain or produce microbes and bacteria. Accordingly, the water is disinfected by adding chlorine gas or powder. The water is then supplied to homes, etc.
Although the tap water is clean and potable, it contains minerals, carbonic acid, chlorine ions, silica, iron, organic components, and the like. The carbonic acid in the tap water derives from carbonic acid compounds in the ground and carbon dioxide in air, the chlorine ions derive from the chlorine gas or powder used for disinfection at the purification plants, and the organic components derive from algae, bacteria, and their decomposed matter contained in raw water. These dissolved substances are not removable at the purification plants and remain in tap water.
Domestic electric appliances such as a humidifier must use such tap water containing dissolved substances. Water particles emitted from the humidifier deposit on household effects such as furniture and evaporate to leave the dissolved substances as white spots on the furniture, etc.
To prevent the white spots, water purifiers using ion exchange resin are marketed. These water purifiers are classified into a general-purpose type and a specific type exclusive for humidifiers.
The ion exchange resin removes not only the dissolved substances that cause the white spots but also residual chlorine (mainly hypochlorous acid) for disinfection. Accordingly, water passed through the ion exchange resin and stored in a tank in the water purifier may easily grow fur and bacteria. When tile humidifier with the water purifier is continuously operated, it will cause no problem of growing fur and bacteria because fresh water is always supplied into the tank through the ion exchange resin. If the humidifier is not used for a while, water in the tank may grow fur and bacteria. If this water is sprayed into air, it will cause a health problem.
The performance of the ion exchange resin quickly deteriorates and must be replaced after a certain period of use (usually about a month and a half). This increases a running cost.
Refrigerators use tap water, too. When the tap water is used as it is for making ice in the refrigerator, +minerals, chlorine ions, etc., dissolved in the water make the ice opaque to degrade its appearance.
SUMMARY OF THE INVENTION
To solve these problems, an object of the present invention is to provide a domestic electric appliance with an electrodialytic water purifier.
Another object of the present invention is to provide a humidifier with an electrodialytic water purifier for preventing white spots on household effects nor fur or bacteria in water stored in the water purifier.
In order to accomplish the objects, the present invention provides a humidifier comprising a removable water tank, an electrode tank, a storage tank, an atomizer, and a blower. The water tank has a filling port that is opened when the water tank is removably set in the humidifier. The electrode tank communicates with the filling port of the water tank. The electrode tank forms an electrodialyzer with an anode, a cathode, cation exchange films, and anion exchange films. The cation and anion exchange films serve as partition walls and are alternately arranged between the anode and the cathode. The atomizer atomizes water in the storage tank. The blower guides the atomized water and blows it outside.
In the humidifier, water is electrodialyzed in the electrode tank, atomized by the atomizer in the storage tank, and blown outside by the blower. The electrodialyzer removes dissolved substances from the water, so that mists blown out of the humidifier will never cause white spots on household effects. Although residual chlorine is also removed from the water, the water will grow no fur or bacteria for a long time in the humidifier because the anode and cathode form an electric field strongly acting on the water. In addition, the electrodialyzer requires no replacement work.
According to another aspect of the present invention, there is provided a humidifier comprising a water tank, first and second storage tanks, an electrodialyzer, an atomizer, and a blower. The electrodialyzer is formed in at least one of the storage tanks with an anode, a cathode, cation exchange films, and anion exchange films. The cation and anion exchange films serve as partition walls and are alternately arranged between tile anode and the cathode. The atomizer is disposed in the second storage tank, to atomize water in the second storage tank. The blower guides the atomized water and blows it outside.
According to still another aspect of the present invention, there is provided a humidifier comprising a removable water tank, an electrodialyzer, a storage tank, and a blower. The water tank is disposed in the humidifier and has an outlet to be opened and closed. The electrodialyzer is formed in the water tank with an anode, a cathode, cation exchange films, and anion exchange films. The cation and anion exchange films serve as partition walls and are alternately arranged between the anode and the cathode. The storage tank communicates with the water tank. The atomizer atomizes water in the storage tank. The blower guides the atomized water and blows it outside. The outlet of the water tank is controlled by valve control means, which closes the outlet for a certain period after the activation of the electrodialyzer and then opens the same. The water tank has an upper lid that is removable when filling water into the water tank.
These and other objects, features and advantages of the present invention will be more apparent from the following detailed description of preferred embodiments in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view showing a humidifier according to an embodiment of the present invention;
FIG. 2 is a sectional view showing a humidifier according to another embodiment of the present invention;
FIG. 3 is a perspective view showing first and second storage tanks of the embodiment of FIG. 2;
FIG. 4 is a sectional view explaining the operation of an electrodialyzer of the embodiment of FIG. 1;
FIG. 5 is a sectional view explaining the operation of an electrodialyzer of the embodiment of FIG. 2;
FIG. 6 is a sectional view showing a humidifier according to still another embodiment of the present invention;
FIG. 7 is a partly sectioned view showing essential part of an upper lid of the embodiment of FIG. 6; and
FIG. 8 is a view showing an ice maker of a refrigerator according to the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
A humidifier according to an embodiment of the present invention will be explained with reference to FIG. 1.
The humidifier 1 has a storage tank 3. A removable water tank 7 is set on the storage tank 3. A removable drain tank 9 is set under the storage tank 3.
The water tank 7 has a threaded cylinder 13 at the bottom thereof. The threaded cylinder 13 forms a filling port 11. A cap 15 serving as a water supply plug is fastened to the threaded cylinder 13. The cap 15 is removable to pour water in the water tank 7. The cap 15 has a valve seat 17 and an open-close valve 19. The valve 19 is usually in contact with the valve seat 17 due to a force applied by a spring 21, to thereby close the filling port 11. When the water tank 7 is set in the humidifier 1, the valve 19 is pushed upwardly by a projection 23 formed in the storage tank 3, to open the filling port 11.
The storage tank 3 forms an electrodialyzer 33 with a cathode 25, a first cation exchange film 27a, a first anion exchange film 29a, a second cation exchange film 27b, a second anion exchange film 29b, and an anode 31.
The anode 31 repels cations (cathodic ions) and attracts anions (anodic ions) dissolved in tap water.
The first and second cation exchange films 27a and 27b serve as partition walls, and when a DC voltage is applied to the electrodes 25 and 31, selectively transmit cations.
The first and second anion exchange films 29a and 29b serve as partition walls, and when a DC voltage is applied to the electrodes 25 and 31, selectively transmit anions.
The cathode 25 repels anions and attracts cations dissolved in tap water.
In the storage tank 3, a first chamber I is defined between the second anion exchange film 29b and an outer wall 3a of the storage tank 3. The anode 31 is located in the first chamber I. A second chamber II is defined between the second anion exchange film 29b and the second cation exchange film 27b. A third chamber III is defined between the second cation exchange film 27b and the first anion exchange film 29a. A fourth chamber IV is defined between the first anion exchange film 29a and the first cation exchange film 27a. A fifth chamber V is defined between the first cation exchange film 27a and the external wall 3a of the storage tank 3. The cathode 25 is located in the fifth chamber V.
The operation of the electrodialyzer 33 will be explained with reference to FIG. 4.
When a voltage is applied to the cathode 25 and anode 31, anions C1- in the second chamber II are transmitted through the second anion exchange film 29b into the first chamber I. Cations Na+ in the second chamber II are transmitted through the second cation exchange film 27b into the third chamber III. Cations Na+ in the first chamber I are repelled by the second anion exchange film 29b and stay in the first chamber I. Anions C1- in the third chamber III are repelled by the second cation exchange film 27b and stay in the third chamber III. As a result, water in the second chamber II is purified.
Cations Na+ in the fourth chamber IV are transmitted through the first cation exchange film 27a into the fifth chamber V. Anions C1- in the fourth chamber IV are transmitted through the first anion exchange film 29a into tile third chamber III. Anions C1- in the fifth chamber V are repelled by the first cation exchange film 27a and stay in the fifth chamber V. Cations Na+ in the third vessel III are repelled by the first anion exchange film 29a and stay in the third chamber III. As a result water in the fourth chamber IV is purified.
The second and fourth chambers II and IV containing the purified water are connected to each other. The first, third, and fifth chambers I, III, and V are connected to an inlet 37 of the drain tank 9 through a drain pipe 35. A drain valve 38 of the drain pipe 35 is opened to drain water with concentrated dissolved ions from the chambers I, III, and V into the drain tank 9.
The drain tank 9 is removable through a door 39 formed at lower part of the humidifier 1. When the drain tank 9 becomes full of drain water, it is removed and emptied.
An ultrasonic element 47 is supported by an element holder 45, which is fixed to the bottom of the fourth chamber IV containing the purified water. The ultrasonic element 47 oscillates to atomize the purified water.
A blower 49 having a fan (not shown) is disposed over the fourth chamber IV. The fan draws outside air through an inlet 51 formed at lower part of the humidifier 1. The air and atomized water are guided upwardly through a guide cylinder 53 and are blown outside through a blow port 55.
In the humidifier 1, water in the water tank 7 is fed into the storage tank 3 through the filling port 11, purified by the electrodialyzer 33, atomized by the ultrasonic element 47 in the fourth chamber IV, guided through the guide cylinder 53, and blown outside from the blow port 55. Since dissolved substances and chlorine are removed from tap water by the electrodialyzer 33, the atomized water blown from the blow port 55 never causes white spots on household effects.
The electrodes 25 and 31 form an electric field acting on the tap water in the storage tank 3, so that the water may cause no fur or bacteria for a long time.
In addition, the electrodialyzer 33 requires no replacement work.
FIGS. 2 and 3 show a humidifier according to another embodiment of the present invention.
This embodiment employs first and second storage tanks 3 and 5. The same parts as those of the first embodiment are represented with like reference marks.
In FIGS. 2 and 3, an anode 31 is located on the left-hand side and a cathode 25 on the right-hand side, to purify water in a third chamber III. The first and second storage tanks 3 and 5 are integral with each other. A removable water tank 7 is disposed on the first storage tank 3. A removable drain tank 9 is disposed under the first storage tank 3.
The water tank 7 has a threaded cylinder 13 at the bottom thereof. The threaded cylinder 13 forms a filling port 11. A cap 15 serving as a water supply plug is fastened to the threaded cylinder 13. The cap 15 is removable to pour water in the water tank 7. The cap 15 has a valve seat 17 and an open-close valve 19. The valve 19 is usually in contact with the valve seat 17 due to force applied by a spring 21, to thereby close the filling port 11. When the water tank 7 is set in the humidifier 1, the valve 19 is pushed upwardly by a projection 23 formed in the first storage tank 3, to open the filling port 11.
The tank 3 forms an electrodialyzer 33 with the anode 31, a first cation exchange film 27a, a first anion exchange film 29a, a second cation exchange film 27b, a second anion exchange film 29b, and the cathode 25.
The anode 31 repels cations and attracts anions dissolved in tap water.
The first and second cation exchange films 27a and 27b serve as partition walls, and when a DC voltage is applied to the electrodes 25 and 31, transmit cations only.
The first and second anion exchange films 29a and 29b serve as partition walls, and when a DC voltage is applied to the electrodes 25 and 31, transmit anions only.
The cathode 25 repels anions and attracts cations dissolved in tap water.
In the storage tank 3, a fifth chamber V is defined between the first cation exchange film 27a and an outer wall 3a of the first storage tank 3. The anode 31 is located in the fifth chamber V. A fourth chamber IV is defined between the first cation exchange film 27a and the first anion exchange film 29a. A third chamber III is defined between the first anion exchange film 29a and the second cation exchange film 27b. A second chamber II is defined between the second cation exchange film 27b and the second anion exchange film 29b. A first chamber I is defined between the second anion exchange film 29b and the external wall 3a of the first storage tank 3. The cathode 25 is located in the first chamber I.
FIG. 5 shows movements of cations Na+ and anions C1- in the first storage tank 3.
The first chamber I, second chamber II, fourth chamber IV, and fifth chamber V of the first storage tank 3 are connected to an inlet 37 of the drain tank 9 through a drain pipe 35. A drain valve 38 of the drain pipe 35 is opened to drain water with concentrated dissolved ions from the chambers I, II, IV, and V into the drain tank 9.
The drain tank 9 is removable through a door 39 formed at lower part of the humidifier 1. When the drain tank 9 becomes full of drain water, it is removed and emptied.
The second storage tank 5 communicates with the third chamber III of the first storage tank 3 through a path 41 as shown in FIG. 3. An open-close valve 43 is disposed in the path 41. The valve 43 is closed for a predetermined time after the water tank 7 is set in the humidifier 1, to prevent unprocessed water from flowing into the second storage tank 5. After the predetermined closure time, the valve 43 is opened.
An ultrasonic element 47 is supported by an element holder 45, which is fixed to the bottom of the second storage tank 5. The ultrasonic element 47 oscillates to atomize water in the second storage tank 5.
A blower 49 having a fan (not shown) is disposed over the tank 5. The fan draws outside air through an inlet 51 formed at lower part of the humidifier 1. The air and atomized water are guided upwardly through a guide cylinder 53 and are blown outside through a blow port
In the humidifier 1, water in the water tank 7 is fed into the first storage tank 3 through the filling port 11, processed by the electrodialyzer 33, sent into the second storage tank 5, atomized by the ultrasonic element 47, guided through the guide cylinder 53, and blown outside from the blow port 55. Since dissolved substances and chlorine are removed from tap water by the electrodialyzer 33, the atomized water blown from the blow port 55 never causes white spots on household effects.
The anode 31 and cathode 25 form an electric field acting on the water in the first storage tank 3, so that the water may cause no fur or bacteria for a long time.
In addition, the electrodialyzer 33 requires no replacement work.
Although the electrodialyzer 33 is disposed in the first storage tank 3 according to the second embodiment, the electrodialyzer 33 may be arranged in each of the first and second storage tanks 3 and 5, or only in the second storage tank 5.
FIG. 6 shows a humidifier according to still another embodiment of the present invention. Unlike the previous embodiments that arrange an electrodialyzer in a storage tank of a humidifier, the embodiment of FIG. 6 forms an electrodialyzer 33 in a water tank 7.
The electrodialyzer 33 in the water tank 7 comprises a cathode 25, a first cation exchange film 27a, a first anion exchange film 29a, a second cation exchange film 27b, a second anion exchange film 29b, and an anode 31.
A tank body 7a of the water tank 7 has a contact S1. The humidifier 1 has a contact S2. When the contact S1 is brought in contact with the contact S2, a current flows from a power source to the electrodes 25 and 31 of the electrodialyzer 33.
In FIG. 7, an upper lid 9 of the water tank 7 is fitted to an upper edge 7b of the tank body 7a through a seal ring 22. A lock arm 26 fixed to the tank body 7a engages with a stopper 24 formed on the periphery of the upper lid 9.
The lock arm 26 is made of elastic synthetic resin and is usually at a locked position indicated with a continuous line. When an outward force is applied by fingers, the lock arm 26 is released from the stopper 24 into an unlocked state indicated with a dotted line.
A projection 23 formed in a storage tank 3 has a tip 23a, which is moved upwardly or downwardly by a solenoid SL. Movable parts of tile projection 23 are covered with a bellows 28 in a watertight manner.
When the tank body 7a is set in the humidifier 1 as shown in FIG. 6, the contact S1 of the tank body 7a is brought in contact with tile contact S2 of the humidifier 1. As a result, a timer T is turned ON to turn OFF the solenoid SL for a set period. After the set period, the solenoid SL is turned ON to extend the projection 23. The tip 23a of the projection 23 then pushes up and opens an open-close valve 19.
This arrangement never lets unprocessed water flow from the water tank 7 into the storage tank 3 just after the tank 7 is set in the humidifier 1.
Although this embodiment employs the timer T to control the solenoid SL, the solenoid SL may be controlled in response to an ion concentration in the tank 7.
The humidifier according to this embodiment is compact because the electrodialyzer 33 is formed in the water tank 7. By removing the upper lid 9, one can quickly pour water into the water tank 7. Water in the water tank 7 is purified by the electrodialyzer 33 and fed into a storage tank 5, In which the purified water is atomized by an atomizer 47 and blown outside.
Dissolved substances that may cause white spots are removed from water by tile electrodialyzer 33. Although the electrodialyzer 33 removes residual chlorine, too, from the water in the water tank 7, the water will grow no fur or bacteria for a long time because the electrodes 25 and 31 of the electrodialyzer 33 form an electric field that strongly acts on the dialyzed water in the water tank 7.
FIG. 8 shows another embodiment of the present invention. Unlike the previous embodiments that employ an electrodialyzer for a humidifier, the embodiment of FIG. 8 employs an electrodialyzer 55 for an ice maker 51 of a freezer 50 in a refrigerator.
The electrodialyzer 55 is formed in a water tank 53. Water is supplied to and purified in the water tank 53. After a predetermined period, the purified water is fed into an ice tray 59 through a valve 57. Ice formed in the tray 59 has a good appearance because dissolved substances have been removed from the water by the electrodialyzer 55.
In summary, the present invention provides domestic electric appliances such as a humidifier with an electrodialyzer that prevents white spots from depositing on household effects. Water in the electrodialyzer grows no fur or bacteria for a long time because the electrodialyzer produces an electric field that strongly acts on the water. Since the electrodialyzer also removes residual ions from water, no scale will accumulate on the surface of an ultrasonic atomizer, to thereby improve the service life and performance of the atomizer. In addition, the electrodialyzer requires no replacement work, to reduce a running cost.
Various modifications will become possible for those skilled in the art after receiving the teachings of the present disclosure without departing from the scope thereof. | A domestic electric appliance comprises a water purifier employing an electrodialyzer. The electrodialyzer includes an anode, a cathode, cation exchange films, and anion exchange films. The cation and anion exchange films are alternately arranged between the anode and the cathode and serve as partition walls. The domestic electric appliance further comprises a unit for using the water purified by the water purifier. | 8 |
FIELD OF THE INVENTION
This invention relates to window locks, and more particularly to window locks for sliding windows.
BACKGROUND OF THE INVENTION
Double-hung and single hung sliding windows include two window sashes typically mounted for vertical movement along adjacent parallel tracks in a window frame. Traditional double-hung window designs provide poor washability, because it is difficult for a person located inside a structure in which the window is installed to wash the outside of the window pane. To fully wash the outer surface of such windows (which outer surface is the one which is most often in need of cleaning), the person cleaning the window must typically go outside the dwelling. This is not only extremely inconvenient, as the person has to walk significant distances merely to wash both sides of a single window, but it can also force a window washer, when trying to wash double and single-hung windows located at significant heights, to face the undesirable choice of either risking injury by climbing to that height or doing a relatively poor job of washing by merely reaching from a distance with a hose or a special long pole apparatus of some type. Such cleaning is still further complicated where there are screens or storm windows that must be removed prior to washing.
To overcome this problem, windows of this type have been developed that enables one or more of the sashes to be tilted inwardly to gain access to the outside surface of the window pane from within the structure. Various types of latching mechanisms have been developed to enable the latch to secure the sash in place in the frame, but also enable tilting the sash by operating the latches. A common arrangement has such latches positioned in opposite ends of a top horizontal rail of the upper and/or lower sash, with each latch typically including a bolt end or plunger which during normal operation extends out from the side of the sash into the sash track in the window frame to guide the sash for typical vertical movement. When washing is desired, a bolt end or plunger of each latch is retracted to free the top rail of the sash from the track so that the sash may be suitably pivoted inwardly about pivots guiding the bottom rail of the sash in the track and thereby allow the washer to easily reach the outside surface of the window pane of that sash.
The bolt end or plunger in many of the prior art latches is usually biased outwardly into the track by a spring structure or the like, with the bolt end retracted inwardly by the washer manually pulling the bolt ends in toward the center of the top rail against the force of the spring as, for example, in the mechanism disclosed in U.S. Pat. No. 5,139,291. A drawback of such mechanisms, however, is that both latches must be operated simultaneously, requiring that the operator use both hands. Moreover, simultaneous operation of latch controls spaced at the far edges of the sash can be awkward, especially for wide windows. Another mechanism, disclosed in U.S. Pat. No. 5,992,907, commonly owned by the owners of the present invention and hereby fully incorporated herein by reference, has a lever operably coupled with a check rail lock assembly that simultaneously operates remotely located tilt-latch assemblies.
Other mechanisms linking tilt latches with a single control that also locks the sashes together are well known. For example, U.S. Pat. No. 5,398,447 (the '447 patent) discloses a tilt-lock latch mechanism wherein a lever positioned proximate the center of the top rail of a lower sash may be rotated in one direction to engage a keeper positioned on the upper sash proximate the lever or in the opposite direction to operate remotely located tilt latches to enable tilting of the lower sash for cleaning. U.S. Pat. No. 5,791,700 (the '700 patent) discloses a tilt lock latch mechanism wherein a single control lever operates both sash locks and remote tilt latches. To accomplish this, the control lever is selectively rotatably positionable in three discrete positions: (1) a first position wherein the sash locks and the tilt latches are engaged; (2) a second position wherein the sash locks are disengaged to enable sliding of the sashes but the tilt latches are still engaged; and (3) a third position wherein the sash locks and the tilt latches are disengaged to enable sliding of the window. Similarly, U.S. Pat. No. 6,817,142 (the '142 patent) and its continuation U.S. application Ser. No. 10/959,696 also disclose a tilt-lock latch mechanism having such a three-position control lever.
Each of the above described mechanisms, however, has certain drawbacks. The '447 patent mechanism, while generally simple, requires rotation of the control lever in opposite directions from a center position for unlocking and tilting. This is inconvenient and may result in unintended tilting operation of the window if an inexperienced user seeking merely to unlock the window rotates the lever in the wrong direction. Also, the '447 patent mechanism requires that a separate control be manipulated by the operator to maintain the control lever in a desired position. The '700 patent mechanism, while enabling same-direction rotation of the control lever, is relatively complex, and may be expensive to manufacture and difficult to install and adjust. The '142 patent mechanism may be difficult to adjust, requiring partial disassembly and manipulation of a screw on the tilt latches for tensioning the strap connecting the control lever with the tilt latches. Moreover, the '142 patent describes a separate button that must be manipulated for engaging or releasing the tilt latches. This may be confusing for a user and result in frustration when attempting to tilt the window for cleaning, or in failure to properly reengage the tilt latches when cleaning is complete.
Another mechanism, described in U.S. Pat. No. 6,877,784, includes a rotary lever with sash lock that actuates remote tilt latches through an extensible member. A drawback of this mechanism, however, is that it is relatively complex, including a spring-loaded control lever and a pivoting trigger release mechanism in each of the tilt latches, making it relatively more expensive to produce and reducing reliability. Further, there are no simple means provided for attaching the extensible member to the tilt latches, nor is any means for adjusting length and tension of the extensible member provided.
U.S. patent application Ser. No. 10/289,803 discloses a similar tilt lock latch mechanism including a three-position control lever that actuates a sash lock as well as remotely located tilt latches. One drawback of this mechanism, however, is that a relatively complicated fastener arrangement is used for connecting the actuator spool to the tilt latch connector, affecting cost of manufacture and usability of the mechanism. Also, the tilt latches are not equipped with any mechanism for holding the latches in the retracted position. When the window is tilted into position after cleaning, the protruding latch-bolts may mar the window frame if the operator forgets to manually retract them. Moreover, a separate button is described that must be manipulated for engaging or releasing the tilt latches, thus complicating operation.
U.S. patent application Ser. No. 11/340,428 also discloses a similar tilt lock latch mechanism including a three-position control lever that actuates a sash lock as well as remotely located tilt latches. One drawback of this mechanism, however, is that the lever may remain in the window-tilt position unless an operator manually returns the lever to the locked or unlocked positions. Also, the lever may remain in an intermediate position unless an operator specifically positions the lever to a tilt, locked, or unlocked position. Moreover, it may be difficult for an operator to judge when the lever has been correctly positioned to a tilt, locked, or unlocked position.
What is still needed is a low-cost combination tilt-lock-latch mechanism for a double-hung window that is easy to install and adjust, simple to use, and is biased toward a locked or unlocked position.
SUMMARY OF THE INVENTION
The present invention addresses the need for a low-cost combination tilt-lock-latch mechanism for a sliding window that combines ease of installation and adjustment, simplicity of use, and a bias toward a locked or unlocked position. In embodiments of the invention, an integrated lock and tilt-latch mechanism for a sliding window includes at least one tilt-latch mechanism adapted for mounting in the window sash. The tilt-latch mechanism includes a housing presenting a longitudinal axis and having an aperture defined in a first end thereof, a plunger having a latch-bolt portion, a plunger-latch member, and first and second biasing members. The plunger is disposed in the housing and is selectively slidably shiftable along the longitudinal axis of the housing between an extended position in which the latch-bolt portion of the plunger projects through the aperture in the housing to engage the window frame so as to prevent tilting of the sash, and a retracted position in which the latch-bolt portion of the plunger is substantially within the housing to enable tilting of the sash. The first biasing member is arranged so as to bias the plunger toward the extended position. The plunger-latch member is operably coupled with the tilt-latch housing and is arranged so as to be selectively slidably shiftable in a direction transverse to the longitudinal axis when the plunger is in the retracted position. The plunger-latch member is shiftable between a first position in which the plunger-latch member engages and prevents shifting of the plunger and a second position in which the plunger-latch member enables shifting of the plunger. The second biasing member is arranged so as to bias the plunger-latch member toward the first position so that when the plunger is retracted, the plunger-latch automatically shifts to retain the plunger in the retracted position. The plunger-latch may include a trigger portion arranged so that when the sash is tilted into position in the frame, the trigger portion contacts the window frame or second sash, shifting the plunger-latch so as to release the plunger. The mechanism further includes an actuator mechanism adapted for mounting on the sash. The actuator mechanism includes a housing, a control on the housing, a lock member, and a tilt-latch actuator member. The lock member and the tilt-latch actuator member are operably coupled with the control. A linking member operably couples the tilt-latch actuator member and the plunger of the tilt-latch mechanism. The control lever is selectively positionable between at least three positions, including a locked position in which the sweep cam is positioned so that a portion of the sweep cam extends under the locking tab of a keeper, an unlocked position in which the sweep cam is substantially retracted from the locking tab of a keeper, and a tilt position in which the sweep cam is retracted and the plunger of the tilt-latch mechanism is positioned in the retracted position.
In another embodiment of the invention, an integrated lock and tilt-latch mechanism for a sliding window having a frame with at least one sliding sash therein, the sash also tiltably positionable relative to the frame, includes an actuator assembly, at least one tilt-latch assembly adapted for mounting on the sash, and a flexible linking member. The actuator assembly includes a housing, a control lever, a lock member, and a tilt-latch actuator member. The lock member and the tilt-latch actuator member are operably coupled with the control, and the tilt-latch actuator has structure for receiving and applying tension to the flexible linking member. The at least one tilt-latch assembly includes a tilt-latch housing presenting a longitudinal axis and having an aperture defined in a first end thereof. A plunger is disposed in the tilt-latch housing, the plunger having a latch-bolt portion and being selectively slidably shiftable along the longitudinal axis between an extended position in which the latch-bolt portion of the plunger projects through the aperture and a retracted position in which the latch-bolt portion of the plunger is substantially within the tilt-latch housing. The plunger defines a channel for receiving the flexible linking member and has a locking member positioned proximate the channel. The locking member is selectively shiftably adjustable from a location outside the tilt-latch housing between a first position in which the flexible linking member is freely slidable in the channel to enable insertion and removal of the flexible linking member, and a second position in which the locking member is engaged with the flexible linking member to fixedly secure the flexible linking member in the channel, thereby operably coupling the tilt-latch actuator with the plunger of the tilt-latch. In a further embodiment of the invention, a window includes a frame and a first sash and a second sash, each slidable in the frame. The first sash is also tiltably positionable relative to the frame. An integrated lock and tilt-latch mechanism is positioned on the first sash, including an actuator mechanism, at least one tilt-latch adapted for mounting on the sash, and a flexible linking member. The actuator mechanism includes a housing, a control, a lock member, and a tilt-latch actuator member. The lock member and the tilt-latch actuator member are operably coupled with the control. The tilt-latch actuator has structure for receiving and applying tension to the flexible linking member. The at least one tilt-latch includes a tilt-latch housing presenting a longitudinal axis and having an aperture defined in a first end thereof, and a plunger disposed in the tilt-latch housing. The plunger has a latch-bolt portion and is selectively slidably shiftable along the longitudinal axis between an extended position in which the latch-bolt portion of the plunger projects through the aperture and a retracted position in which the latch-bolt portion of the plunger is substantially within the tilt-latch housing. The plunger defines a channel for receiving the flexible linking member and has a locking member positioned proximate the channel. The locking member is selectively shiftably adjustable, from a location outside the tilt-latch housing, between a first position in which the flexible linking member is freely slidable in the channel to enable insertion and removal of the flexible linking member, and a second position in which the locking member is engaged with the flexible linking member to fixedly secure the flexible linking member in the channel, thereby operably coupling the tilt-latch actuator with the plunger of the tilt-latch. The control is selectively positionable between at least three positions, including a locked position in which the lock member is positioned so that a portion of the lock member extends from the housing of the actuator mechanism, an unlocked position in which the lock member is positioned substantially within the housing of the actuator mechanism, and a tilt position in which the lock member is positioned substantially within the housing of the actuator mechanism and the plunger of the tilt-latch mechanism is positioned in the retracted position.
In yet another embodiment of the invention, a window includes a frame and a first and a second sash, each sash slidable in the frame, wherein the first sash is also tiltably positionable relative to the frame. An integrated lock and tilt-latch mechanism is positioned on the first sash, the mechanism including at least one tilt-latch mechanism having a housing presenting a longitudinal axis, a plunger having a latch-bolt portion, a plunger-latch member, and first and second biasing members. The plunger is disposed in the housing and is selectively slidably shiftable along the longitudinal axis between an extended position in which the latch-bolt portion of the plunger engages the frame of the window to prevent tilting of the first sash and a retracted position in which the latch-bolt portion of the plunger is substantially within the housing to enable tilting of the first sash. The first biasing member is arranged so as to bias the plunger toward the extended position. The plunger-latch member is operably coupled with the housing and arranged so as to be selectively slidably shiftable in a direction transverse to the longitudinal axis when the plunger is in the retracted position. The plunger-latch member is shiftable between a first position in which the plunger-latch member engages and prevents shifting of the plunger and a second position in which the plunger-latch member enables shifting of the plunger. The second biasing member is arranged so as to bias the plunger-latch member toward the first position. The mechanism further includes an actuator mechanism including a housing, a control on the housing, a lock member, and a tilt-latch actuator member. The lock member and the tilt-latch actuator member are operably coupled to the control with a linking member operably coupling the tilt-latch actuator member and the plunger of the at least one tilt-latch mechanism. The control is selectively positionable among at least three positions, including a locked position in which a sweep cam is engaged with a keeper of the second sash to prevent relative sliding movement of the first and second sashes, an unlocked position in which the lock member is free from the keeper of the second sash, and a tilt position in which the lock member is free from the keeper of the second sash and the plunger of the tilt-latch mechanism is positioned in the retracted position to enable tilting of the first sash.
In another embodiment, the control lever is biased toward a locked position or an unlocked position. The sweep cam of the control lever is selectively shiftably adjustable from between a first position in which the flexible linking member is freely slidable in the channel to enable insertion and removal of the flexible linking member, and a second position in which the locking member is engaged with the flexible linking member to fixedly secure the flexible linking member in the channel, thereby operably coupling the tilt-latch actuator with the plunger of the tilt-latch. The control lever is selectively positionable between at least three positions including a locked position in which the sweep cam engages a keeper, an unlocked position in which the sweep cam is disengaged from the keeper, and a tilt position in which the sweep cam is disengaged from the keeper and the plunger of the tilt-latch mechanism is positioned in the retracted position. Depending upon the position of the control lever, the control member is biased toward the locked position or the unlocked position. In the tilt position and intermediate the tilt position and the unlocked position, the control is biased toward the unlocked position. Intermediate the unlocked position and the locked position, the control is biased toward the unlocked position or the locked position, dependent on which position the control is most proximate.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an actuator assembly in a locked position according to an embodiment of the present invention;
FIG. 2 is a top view of an actuator assembly in a locked position according to an embodiment of the present invention;
FIG. 3 is a side view of an actuator assembly in a locked position according to an embodiment of the present invention;
FIG. 4 for a rear view of an actuator assembly in a locked position according to an embodiment of the present invention;
FIG. 5 is a side view of an actuator assembly in a locked position according to an embodiment of the present invention;
FIG. 6 is a front view of an actuator assembly in a locked position according to an embodiment of the present invention;
FIG. 7 is a perspective view of an actuator assembly in a locked position according to an embodiment of the present invention;
FIG. 8 is a top view of an actuator assembly in a locked position according to an embodiment of the present invention;
FIG. 9 is a side view of an actuator assembly in a locked position according to an embodiment of the present invention;
FIG. 10 is a rear view of an actuator assembly in a locked position according to an embodiment of the present invention;
FIG. 11 is a side view of an actuator assembly in a locked position according to an embodiment of the present invention;
FIG. 12 is a front view of an actuator assembly in a locked position according to an embodiment of the present invention;
FIG. 13 is a perspective view of a double-hung window with an integrated lock and tilt-latch assembly according to an embodiment of the present invention;
FIG. 14 is a perspective view of a window sash with an integrated lock and tilt-latch assembly according to an embodiment of the present invention;
FIG. 15 is a perspective view of a window sash with an actuator assembly according to an embodiment of the present invention;
FIG. 16 is an exploded perspective view of an actuator assembly according to an embodiment of the present invention;
FIG. 17 is a sectional perspective view of an actuator assembly in a locked position according to an embodiment of the present invention;
FIG. 18 is a sectional perspective view of an actuator assembly in a locked position according to an embodiment of the present invention;
FIG. 19 is a sectional perspective view of an actuator assembly in a locked position according to an embodiment of the present invention;
FIG. 20 is sectional perspective view of an actuator assembly in an unlocked position according to an embodiment of the present invention;
FIG. 21 is a sectional perspective view of an actuator assembly in a tilt position according to an embodiment of the present invention;
FIG. 22 is an exploded view of a tilt-latch assembly according to an embodiment of the invention;
FIG. 23 is an exploded view of a tilt-latch assembly according to another embodiment of the invention;
FIG. 24 is a cross-sectional view of the plunger portion of a tilt-latch assembly taken at Section 7 - 7 of FIG. 23 ;
FIG. 25 is a perspective view of a first portion of the housing of the tilt-latch assembly of FIG. 23 ;
FIG. 26 is a side elevation view of the housing portion depicted in FIG. 25 ;
FIG. 27 is a perspective view of a second portion of the housing of the tilt-latch assembly of FIG. 23 ;
FIG. 28 is a side elevation view of the housing portion depicted in FIG. 27 ;
FIG. 29 is an exploded view of a tilt-latch assembly according to an embodiment of the invention;
FIG. 30 is an exploded view of the tilt-latch portion of an integrated lock and tilt-latch assembly according to an embodiment of the present invention;
FIG. 31 is a perspective view of a tilt-latch assembly according to an embodiment of the invention with the housing depicted in phantom to reveal structures enabling locking of a linking member from outside the housing with a wrench;
FIG. 32 depicts the tilt-latch assembly of FIG. 31 with the Allen wrench engaged with the locking cam member;
FIG. 33 is a perspective view of a tilt-latch assembly according to an embodiment of the invention with the housing depicted in phantom revealing the linking-member passage and locking member prior to locking of the linking member;
FIG. 34 depicts the tilt-latch assembly of FIG. 33 with the locking cam member positioned to lock the linking member to the plunger.
FIG. 35 is a cross-sectional view of a plunger showing how a linking member is terminally attached according to an alternative embodiment of the invention;
FIG. 36 is a top view of the plunger depicted in FIG. 35 ;
FIG. 37 is a bottom view of the plunger depicted in FIG. 35 ;
FIG. 38 is a perspective view of the plunger depicted in FIG. 35 ;
FIG. 39 is a cross-sectional view of a plunger showing how a linking member is terminally attached according to an embodiment of the invention;
FIG. 40 is a top view of the plunger depicted in FIG. 39 ;
FIG. 41 is a bottom view of the plunger depicted in FIG. 39 ;
FIG. 42 is a perspective view of the plunger depicted in FIG. 39 ;
FIG. 43 is a cross-sectional view of a U-shaped component used to terminally attach a flexible linking member to the plunger depicted in FIG. 39 ;
FIG. 44 is a cross-sectional view of a plunger showing how a linking member is terminally attached according to an alternative embodiment of the invention;
FIG. 45 is a top view of the plunger depicted in FIG. 44 ;
FIG. 46 is a top view of the plunger depicted in FIG. 44 ;
FIG. 47 is a perspective view of the plunger depicted in FIG. 44 ;
FIG. 48 is a cross-sectional view of a plunger showing how a linking member is terminally attached according to an alternative embodiment of the invention;
FIG. 49 is a top view of the plunger depicted in FIG. 48 ;
FIG. 50 is a bottom view of the plunger depicted in FIG. 48 ; and
FIG. 51 is a perspective view of the plunger depicted in FIG. 48 .
FIG. 52 is a front view of a base housing of a base assembly according to an embodiment of the present invention.
FIG. 53 is a top view of a base housing of a base assembly according to an embodiment of the present invention.
FIG. 54 is a bottom view of a base housing of a base assembly according to an embodiment of the present invention.
FIG. 55 is a perspective view of a base housing of a base assembly according to an embodiment of the present invention.
FIG. 56 is a side view of a base housing of a base assembly according to an embodiment of the present invention.
FIG. 57 is a top view of a control lever of an actuator assembly according to an embodiment of the present invention.
FIG. 58 is a bottom view of a control lever of an actuator assembly according to an embodiment of the present invention.
FIG. 59 is a rear view of a control lever of an actuator assembly according to an embodiment of the present invention.
FIG. 60 is a side view of a control lever of an actuator assembly according to an embodiment of the present invention.
FIG. 61 is a perspective view of a control lever of an actuator assembly according to an embodiment of the present invention.
FIG. 62 is a top view of a baseplate of a base assembly according to an embodiment of the present invention.
FIG. 63 is a side view of a baseplate of a base assembly according to an embodiment of the present invention.
FIG. 64 is a perspective view of a baseplate of a base assembly according to an embodiment of the present invention.
FIG. 65 is a top view of a gear of a base assembly according to an embodiment of the present invention.
FIG. 66 is bottom view of a gear of a base assembly according to an embodiment of the present invention.
FIG. 67 is a perspective view of a gear of a base assembly according to an embodiment of the present invention.
FIG. 68 is a side view of a gear of a base assembly according to an embodiment of the present invention.
FIG. 69 is a side view of a spool of a base assembly according to an embodiment of the present invention.
FIG. 70 is a perspective view of a spool of a base assembly according to an embodiment of the present invention.
FIG. 71 is a bottom view of a spool of a base assembly according to an embodiment of the present invention.
FIG. 72 is a top view of a spool of a base assembly according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Locking tilt-latch assembly 100 is generally mounted onto double-hung window, as depicted in FIG. 13 . As depicted in FIG. 14 , locking tilt-latch assembly 100 generally includes actuator assembly 102 , tilt-latch assemblies 104 , and linking member 106 . Actuator assembly 102 generally includes base assembly 108 and control lever 110 . Base assembly 108 is defined by baseplate 112 and base housing 114 . In an example embodiment, baseplate 112 and base housing 114 are assembled together such that baseplate 112 defines the top of base assembly 108 , as depicted in FIG. 15 . Control lever 110 has handle 116 , sweep cam 118 , and shank 120 . Sweep cam 118 is generally tapered away from handle 116 . As control lever 110 rotates, sweep cam 118 engages or disengages keeper 122 . When control lever 110 is in a locked position, as depicted in FIG. 15 , sweep cam 118 is positioned under and within locking tab 124 of keeper 122 . Inside sash 310 of double-hung sash window 312 is thereby substantially prevented from being raised relative to frame 334 .
Control lever 110 is coupled to base housing 114 through shank-receiving aperture 126 . Shank-receiving aperture 126 receives shank 120 of lever 110 therethrough. Shank 120 defines upper portion 128 , lower portion 130 , and middle portion 132 . Upper portion 128 is generally cylindrical in shape. Upper portion 128 defines mating cylinder 134 with lateral surface 134 A and outer edge 134 B. Stop 136 is located on outer edge 138 A of mating cylinder 134 . Middle portion 132 is generally quadrangular in shape. Middle portion 132 forms cam 158 that may be trapezoidal in shape with acute corners 158 A-B and obtuse corners 158 C-D, as depicted in FIGS. 19-21 . Lower portion 130 is generally cylindrical in shape. Lower portion 130 forms multi-level protrusions 138 . Large-diameter protrusion 138 A extends outwardly from cam 158 , while small-diameter protrusion 138 B extends outwardly from large-diameter protrusion 138 A. Lip 139 is formed where large-diameter protrusion 138 A and small-diameter protrusion 138 B meet. Retainer 156 is received on small-diameter protrusion 138 B of lower portion 130 of shank 120 . Retainer 156 retains baseplate 112 and lever 110 on base housing 114 so that control lever 110 is rotatable about axis A-A relative to base housing 114 , as annotated in FIG. 14 .
As depicted in FIGS. 14-18 , base assembly 108 generally includes baseplate 112 , base housing 114 , retainer 156 , gear 160 , spool 162 , and biasing member 164 . Underside 170 of base housing 114 defines recesses. The recesses include deep recess portion 173 and shallow recess portion 174 . Underside 170 has upper ceiling 177 A, lower ceiling 177 B, and edge 181 . The recesses receive middle portion 132 and lower portion 130 of shank 120 , gear 160 , a portion of spool 162 , and biasing member 164 . Upper ceiling 177 A defines deep recess portion 173 and lower ceiling 177 B defines shallow recess portion 174 . Deep recess portion 173 has main recess portion 173 A and side recess portions 173 B-C. Edge 181 , deep recess wall 183 , and shallow recess wall 185 define the shape of deep recess portion 173 and shallow recess portion 74 . Deep recess portion 173 is shaped conformingly to, and receives baseplate 112 . The plane formed by edge 181 of base housing 114 defines the lower planar boundary of underside 170 .
Extending downward from lower ceiling 177 B are recess posts 140 . Recess posts 140 generally are integral with upper ceiling 177 A and lower ceiling 177 B and do not extend beyond the plane formed by edge 181 of base housing 114 . Recess posts 140 have main support sections 142 and support surfaces 143 . Support surfaces 143 of recess posts 140 are substantially coplanar. Support posts 140 A-B proximal to spool post 190 may have tip sections 144 . When baseplate 112 is situated on recess posts 140 in deep recess portion 173 , tip sections 144 resist lateral movement of baseplate 112 . Lateral surface of tip sections 144 and edge 181 of base housing 114 are generally coplanar. Inner edges 146 of supports posts 140 and upper recess wall 183 are also generally coplanar. Inner edges 146 are substantially perpendicular to upper ceiling 177 AA and lower ceiling 177 B. Outer edges 148 of recess posts 140 are also substantially perpendicular to upper ceiling 177 AA and lower ceiling 177 B.
Also extending downward from lower ceiling 177 B are mounting posts 186 . Mounting posts define apertures 194 extending from underside 170 to top surface 178 of base housing 114 . Apertures 194 receive fastening members which may be used to secure base assembly 108 to top surface 316 of double hung sash window 312 .
Referring to FIGS. 17-21 , biasing member 164 is secured in deep recess portion 173 between recess posts 140 . Biasing member may be any number of flexible materials possessing shape memory characteristics, such as, for example, a spring in the geometry depicted in an example embodiment of the present invention or in a variety of other geometries that would impart biasing upon cam followers 219 or gear 160 and cam 158 . Cam 158 and cam followers 219 are situated between flex regions 150 , 152 of biasing member 164 . Flex regions 150 , 152 extend through main recess portion 173 A and into side recess portions 173 B,C. Generally, the distance between flex regions 150 , 152 is approximately the distance between obtuse corners 158 A,B of cam 158 . In the embodiment depicted in FIG. 16 , biasing member 164 also has curved joining region 154 . Although only one biasing member 164 is depicted in FIGS. 16-21 , alternative embodiments may include a pair of separate biasing members 164 — each biasing member 164 providing a separate flex region 150 or 152 — secured in deep recess portion 173 between recess posts 140 .
Shank-receiving aperture 126 extends from deep recess portion 173 to top surface 178 of base housing 114 . A boss (not shown) surrounds shank-receiving aperture 176 on top surface 178 of base housing 114 . The boss defines a semi-circular inner recess (not shown) around shank-receiving aperture 176 . The semi-circular inner recess (not shown) intersects an inner edge (not shown) of shank-receiving aperture 176 . Stop 136 outer edge 134 B of mating cylinder 134 of shank 120 is received in semi-circular inner recess 182 . Stop 136 is situated substantially within the semi-circular inner recess. When upper portion 128 is positioned within shank-receiving aperture 176 , the semi-circular inner recess forms a channel defined by outer edge 134 B of mating cylinder 134 of shank 120 and the inner edge of the boss. The length of the semi-circular inner recess thereby limits the rotation of control lever 110 about axis A-A relative to base housing 114 .
Spool post 190 projects downwardly from underside 170 of base housing 114 . Spool post 190 generally is formed from wall 191 defining aperture 192 . Aperture 192 is aligned in the longitudinal direction of base housing 114 . Aperture 192 extends outwardly from underside 170 of base housing 114 . Spool post 190 may also be a solid post such that spool post 190 does not have an aperture.
As depicted in FIG. 16 , baseplate 112 generally has main portion 198 defining aperture 200 , recessed retainer-holding area 202 , semi-circular receiving opening 204 , and alignment lugs 206 . Baseplate 112 also has ears 208 . Aperture 200 receives lower portion 130 of shank 120 . Retainer 156 can be situated in recessed retainer-holding area 202 . When retainer 156 is situated in recessed retainer-holding area 202 , bottom surface 199 of main portion 198 and bottom surface 156 A of retainer 156 are substantially coplanar. Semi-circular receiving opening 204 receives spool 162 . Alignment lugs 206 extending downward at or near the perimeter of semi-circular receiving opening 204 to substantially retain spool 162 in the longitudinal direction of base housing 114 .
Gear 160 has non-gear segment 210 , gear hole 212 , and gear segment 214 extending radially from gear hole 212 , as depicted in FIG. 16 . Gear segment 214 is formed in outer wall 221 of gear 160 . Gear 160 has a top surface (not shown) opposite bottom surface 218 . The top surface and bottom surface 218 are substantially parallel with upper ceiling 177 AA and lower ceiling 177 B. The top surface generally has recessed region (not shown). Extending upward from the top surface and the recessed region are cam followers 219 . Circumference of recessed region 120 is substantially circular. The diameter of the recessed region is substantially the same as the linear distance between acute corners 158 A-B of cam 158 such that cam 158 fits within the recessed region. The linear distance between tips 219 A of cam followers 219 is greater than the linear distance between obtuse corners 158 C-D of cam 158 .
Gear 160 is rotatably received in deep recess portion 173 of underside 170 of base housing 114 . Bottom surface 218 faces downward and the top surface faces upward. Gear segment 214 faces toward spool post 190 and non-gear segment 210 faces away from spool post 190 . Shank 120 of control lever 110 extends through gear hole 212 of gear 160 . Lower portion 130 extends through gear hole 212 such that both large-diameter protrusion 138 A and small-diameter protrusion 138 B extend downward through gear hole 212 past bottom surface 218 . Generally, shank 120 of control lever 110 is inserted through aperture 126 of base housing 114 and lower portion 130 of shank 120 is inserted through gear hole 212 of gear 160 . Cam followers 219 occupy the space between acute corners 158 A,B of cam and opposite biasing members 164 , as depicted in FIG. 17-21 . Lateral surfaces (not shown) of cam followers 219 coextensively interact with upper ceiling 177 A and lateral surface 134 A of mating cylinder 134 .
Spool 162 generally includes lower portion 380 and upper portion 382 , as depicted in FIG. 16 . Lower portion 380 defines slots 384 extending upwardly from bottom edge 385 . Slots 384 may have chamfered edges 386 . Lower portion 380 may be tapered such that the circumference of lower portion 380 decreases toward lower portion 380 . Upper portion 382 defines gear sector 388 . Gear sector 388 is formed in a portion of top edge 166 of upper portion 382 and matingly engages gear segment 214 of gear 160 . Between lower portion 380 and upper portion 382 is spool lip 390 . Spool lip 390 presents a raised edge that circumferentially extends beyond lower portion 380 and upper portion 382 .
Spool 162 is rotatably received by semi-circular receiving opening 204 of baseplate 112 and rotatably positioned over spool post 190 . Lower portion 380 of spool 162 extends below baseplate 112 and upper portion 382 of spool 162 extends above baseplate 112 proximate the lower surface of spool lip 390 . Alignment lugs 206 stabilize spool 162 on spool post 190 . Alignment lugs 206 also present a barrier that prevents spool lip 390 from passing through semi-circular receiving opening 204 . With baseplate 112 secured in place by retainer 156 , spool 162 is secured in place from above by lower ceiling 177 B and from below by semi-circular receiving opening 204 . Movement of spool 162 is thereby substantially limited to rotational movement around spool post 190 .
Gear 160 and spool 162 are desirably made from easily moldable, durable polymer material such as acetal or nylon. Control lever 110 and base housing 114 are preferably cast from suitable metallic material such as zinc alloy. Baseplate 112 and biasing member 164 are preferably die cut or stamped from metallic sheet material. Any of the above components, however, may be made from any other suitable material such as polymer or metal. In the depicted embodiments, actuator assembly 102 is easily assembled by mating control lever 110 and base housing 114 . Biasing member 164 may then be placed in deep recess portion 173 between side recess portions 173 B,C about obtuse corners 158 C,D of cam 158 . With control lever 110 positioned in an unlocked position, lower portion 130 of shank 120 may receive gear 160 such that gear segment 214 faces spool post 190 and cam followers 219 are situated between biasing members 164 . Upper portion 382 of spool 162 is positioned about spool post 190 so that gear sector 388 of spool 162 matingly engages gear segment 214 of gear 160 and slots 384 are aligned parallel to flexible linking member 106 . Baseplate 112 is positioned such that semi-circular recess 182 receives spool 162 , spool 162 enters baseplate 112 from the top surface (not shown) and exits bottom surface 199 of baseplate 112 . Aperture 200 of baseplate 112 receives lower portion 130 of shank 120 . Ears 208 of baseplate 112 rest between recess posts 140 on support surfaces 144 of recess posts 140 . Retainer 156 is assembled to small-diameter protrusion 138 B within recessed retainer-holding area 202 and mechanically secured with a fastening member, such as, for example, a stake or spinning apparatus in example embodiments. Retainer 156 is pushed or pressed about small-diameter protrusion 138 B with locking tab features so as to be secured within recessed retainer-holding area 202 .
Referring to FIG. 17-21 , underside 170 of actuator assembly 102 is shown with control lever 110 in locked ( FIGS. 17-19 ), unlocked ( FIG. 20 ), and tilt ( FIG. 21 ) positions. Although the following description of how actuator assembly 102 functions is made in relation to the orientation of actuator assembly 102 depicted in the figures, it should be understood that directional descriptions would be reversed when actuator assembly 102 is installed and underside 170 is facing downward. For example, clockwise rotation of spool 162 in relation to the orientation of actuator assembly 102 depicted in FIGS. 17-21 corresponds to counter-clockwise rotation of control lever 110 in actuator assembly 102 installed on top surface 316 of double hung sash window 312 .
Referring to FIGS. 17-19 , control lever 110 is in a locked position. In the locked position, handle 116 is approximately in an nine-o'clock position and acute corners 158 A, B of cam 158 are approximately in a ten-o'clock-to-four-o'clock position. The position of control lever 110 depicted in FIGS. 17-19 is in the same locked position occupied by control lever 110 depicted in FIG. 15 , which illustrates an installed tilt lock latch assembly 100 . The resiliency of biasing member 164 substantially maintains cam 158 in place so that control lever 110 remains in the locked position.
To disengage sweep cam 118 from keeper 122 , control lever 110 is rotated in a clockwise direction to an unlocked position, as depicted in FIG. 20 . In the unlocked position, control lever 110 is approximately in a two-o'clock position and acute corners 158 A, B of cam 158 are approximately in a two-o'clock-to-eight-o'clock position. By rotating control lever 110 in a clockwise direction, cam 158 is able to rotate between cam followers 219 without rotationally engaging gear 160 . Since gear 160 remains rotationally stationary as control lever 110 is rotated from the locked position to the unlocked position, spool 162 is not rotationally actuated.
Referring to FIGS. 17-19 , control lever 110 is shown in the locked position with sweep cam 118 positioned so as to engage keeper 122 . Cam 158 is positioned between flex regions 150 , 152 of biasing member 164 . In other embodiments, cam 158 is positioned between two substantially parallel biasing members 164 . When control lever 110 is in the locked position, biasing member 164 restrains cam 158 rotationally and is neutrally biased, exerting no biasing force on cam 158 , as depicted in FIGS. 17-19 . Thus, biasing member 164 provides a favored position for control lever 110 in the locked position.
If cam 158 is rotated clockwise as depicted in FIGS. 17-19 (from a normal, or overhead, view as depicted in FIG. 15 , the direction would be reversed), however, biasing member 164 will be biased in deformation and will exert a steadily increasing biasing force in an opposite, or a counter-clockwise, direction. This counter-clockwise biasing force serves as a “soft” rotational stop for cam 158 in the clockwise rotational direction from the locked position. Cam 158 is substantially prevented from counter-clockwise rotation from locked position by stop 136 , which impedes counter-clockwise rotation from the locked position upon reaching the end of semi-circular recess 182 of base housing 114 .
If control lever 110 is rotated further in the clockwise direction, cam 158 can be positioned so that the biasing force exerted by biasing member 164 is directed through the center of cam 158 . In this intermediate position, which can include a range of rotational travel, biasing member 164 exerts little or no rotational biasing force on cam 158 . Rather, biasing member 164 restrains cam 158 between the locked and unlocked positions. In the intermediate position, sweep cam 118 may partially engage keeper 122 . The range in which cam 158 is restrained in the intermediate position is substantially determined by the biasing force of biasing member 164 and the shape of cam 158 . The corners 158 A-D of cam 158 can be rounded to eliminate or minimize the movement-deadening effect on cam 158 of the intermediate position. In an example embodiment, corners 158 A-D of cam 158 are sounded so as to have substantially similar radii of curvature.
As control lever 110 is further rotated in the clockwise direction past the intermediate position, biasing member 164 exerts a biasing force, now urging cam 158 in the clockwise direction. The rotational biasing force exerted by biasing member 164 steadily decreases as biasing member 164 returns to form. Once cam 158 reaches the unlocked position as shown in FIG. 20 , biasing member 158 again reaches a neutral position and exerts no rotational biasing force in either direction. Thus, biasing member 164 has another favored position in the unlocked position. As before, if cam 158 is rotated further clockwise from this neutral position, biasing member 164 is loaded in deformation and exerts a steadily increasing rotational biasing force urging cam 158 and cam followers 21 counter-clockwise with a higher force than previously experienced due to the increased deformation caused by the addition of cam followers 219 . Therefore, when control lever 110 is further rotated in the clockwise direction to a tilt position, as depicted in FIG. 21 , and then released the biasing force of biasing member 164 on cam 158 and cam follower 219 returns control lever 110 and cam 158 to the unlocked position.
To tilt inside sash 310 of double-hung sash window 312 , control lever 110 is rotated in a clockwise direction to a tilt position, as depicted in FIG. 21 . In the tilt position, handle 116 is approximately in a three-o'clock position and acute corners 158 A,B of cam 158 are approximately in a four-o'clock-to-ten-o'clock position. By continuing to rotate control lever 110 in a clockwise direction, the rotation of cam 158 causes acute corners 158 A,B to rotate cam followers 219 of gear 160 in a clockwise direction. As gear 160 rotates, gear segment 214 rotationally engages gear sector 388 of spool 162 . Since gear 160 rotates in a clockwise direction, spool 162 is caused to rotate in a counter-clockwise direction. As cam 158 rotates in a clockwise direction from the unlocked position to the tilt position, biasing member 164 exerts parallel forces on cam followers 219 that increasingly resist clockwise rotation of gear 160 . As depicted in FIG. 21 , the continued clockwise rotation of control lever 110 and cam 158 past the tilt position when control lever 110 is fully in the tilt position is impeded by stop 136 , which impedes clockwise rotation from the tilt position upon reaching the end of semi-circular recess 182 of base housing 114 . The position of stop 136 in relation to gear segment 214 also prevents the cam 158 -cam followers 219 combination from reaching or passing the directional fulcrum created by the forces exerted by biasing member 164 on cam followers 219 . Therefore, at any point between the unlocked position and the tilt position, control lever 110 will return to the unlocked position if an operator removes the rotational force from control lever 110 .
As depicted in FIGS. 22-50 , each tilt-latch assembly 104 generally includes housing 220 , plunger 222 , primary spring 224 , plunger-latch 226 , latch spring 228 , and locking cam 230 . Housing 220 , generally includes barrel portion 232 and face plate 234 . In embodiments of the invention as depicted, for example, in FIGS. 5 , 6 , 8 - 11 , and 13 , housing 220 may be formed in two sections 236 , 238 , which mate along the longitudinal axis of housing 220 . In these embodiments first housing section 236 has projecting hooks 240 , which engage shoulder structures 242 of second housing section 238 to secure the two sections 236 , 238 , together. Second housing section 238 may also have locating pins 244 , which are received in recesses 246 to inhibit relative movement between the sections 236 , 238 .
Plunger 222 generally includes latch-bolt portion 248 , central body portion 250 , and tail portion 252 . End 253 of latch-bolt portion 248 is tapered from leading edge 253 A to shoulder 253 B. Channel 254 extends axially from end 256 through tail portion 252 . Central body portion 250 defines lock cavity 258 which includes a first portion 260 extending longitudinally within plunger 222 , and a second portion 262 extending transversely to first portion 260 . Channel 254 continues axially from tail portion 252 through second portion 262 of lock cavity 258 , and emerges at outer surface 264 of central body portion 250 proximate shoulder 253 B of latch-bolt portion 248 .
Plunger 222 is received in barrel portion 232 of housing 220 with latch-bolt portion 248 extending through conformingly shaped aperture 266 defined by face plate 234 . Primary spring 224 is received over tail portion 252 and bears against back wall 268 of housing 220 and central body portion 250 to bias plunger 222 toward face plate 234 .
Locking cam 230 generally includes axle portion 270 and radial protrusion 272 . End 274 of axle portion 270 has hex socket 276 adapted to receive an Allen wrench of standard dimension. Locking cam 230 is received in lock cavity 258 with axle portion 270 extending axially and rotatable within first portion 260 and radial protrusion 272 within second portion 262 . Bore 278 is axially aligned with axle portion 270 and extends from first portion 260 of lock cavity 258 through to front end 280 of central body portion 250 proximate face 282 of latch-bolt portion 248 . Adjustment latch arm 284 extends rearwardly from front wall 286 of central body portion 250 , and includes angled portion 288 which intersects bore 278 and laterally projecting tab 290 at end 292 .
Plunger-latch 226 has plate portion 294 defining aperture 296 which is conformingly shaped with the cross-section of latch-bolt portion 248 . Trigger portion 298 extends from plate portion 294 and has bent end portion 300 . Plate portion 294 is slidingly received in transverse slot 302 in face plate 234 . Latch spring 228 is received in recess 304 and bears against edge 306 of plate portion 294 to bias plunger-latch 226 in the direction of trigger portion 298 .
In embodiments of the invention housing 220 and plunger 222 of locking tilt-latch assembly 100 are made from low-cost, easily formable acetal polymer material. These components, however, may also be made from any material having sufficient strength and suitable durability characteristics. Primary spring 224 , plunger-latch 226 , latch spring 228 , and locking cam 230 are desirably made from metallic material, but may also be made from any other suitable material. In the depicted embodiments, locking tilt-latch assembly 100 may be easily assembled by first assembling plunger-latch 226 and latch spring 228 with separate housing sections 236 , 238 , and locking cam 230 and primary spring 224 with plunger 222 . Plunger 222 may then be placed in one of housing sections 236 , 238 , and the housing sections snapped together by mating projecting hooks 240 with shoulder structures 242 and locating pins 244 with recesses 246 .
Referring to FIG. 13 , locking tilt-latch assembly 100 is received in top rail 308 of inside sash 310 of a double-hung sash window 312 . Top rail 308 generally has a cavity (not shown) defined in top surface 316 for receiving base assembly 108 with spool 162 disposed in lower cavity portion 318 . A lateral bore (not shown) extends between the side faces (not shown) of top rail 308 and intersects the lower cavity portion.
Locking tilt-latch assembly 100 may be assembled by linking each of two tilt-latch assemblies 104 disposed in the lateral bore of the window 312 with linking member 106 , and placing actuator assembly 102 in the cavity to engage linking member 106 with spool 162 . Linking member 106 is preferably formed from a suitable stretch-resistant flexible polymer material. Linking member 106 is engaged with the first tilt latch assembly by inserting an Allen wrench through bore 278 and engaging hex socket 276 of locking cam 230 as depicted in FIGS. 34-35 . As the Allen wrench is inserted, it forces adjustment latch arm 284 outwardly toward barrel portion 232 of housing 220 , engaging tab 290 in aperture 326 to lock plunger 222 axially within housing 220 as the adjustment is made. Once engaged in hex socket 276 , the Allen wrench is rotated to rotate locking cam 230 so that radial protrusion 272 is clear of channel 254 . An end 328 of linking member 106 is then inserted in channel 254 at end 256 and threaded through channel 254 until it extends from housing 220 proximate latch-bolt portion 248 as depicted in FIG. 42 . The Allen wrench is then rotated in the opposite direction as depicted in FIG. 43 to rotate locking cam 230 so that radial protrusion 272 forces linking member 106 into second portion 262 of lock cavity 258 . In this position, linking member 106 is frictionally locked within and secured to plunger 222 . The Allen wrench is then withdrawn from bore 278 , enabling tab 290 to recede from aperture 326 . Excess linking member 106 may then be trimmed off flush with face plate 234 .
With the first tilt-latch assembly 104 disposed in, and linking member 106 extending through, lateral bore 320 and trigger portion 298 facing outer sash 327 , linking member 106 may be engaged with the second tilt-latch assembly 104 by the same process as described above. With the second tilt-latch assembly 104 disposed in lateral bore 320 with trigger portion 298 facing outer sash 327 , and with the Allen wrench inserted in bore 278 of the first tilt-latch assembly 104 to prevent its plunger 222 from being retracted, linking member 106 is drawn relatively taut before being locked in place and trimmed. Once linking member 106 is in place and taut, base assembly 108 of actuator assembly 102 may be dropped into cavity 314 so that spool 162 is received in lower cavity portion 318 . As spool 162 enters lower cavity portion 318 , chamfered edges 386 guide linking member 106 into slots 384 of spool 162 respectively. Fasteners 328 may then be driven through mounting posts 186 to secure actuator assembly 102 to top rail 308 and base assembly 108 engaged with linking member 106 to complete assembly.
In operation, with inside sash 310 and outer sash 327 in a closed position as depicted in FIG. 13 , control lever 110 may be positioned in a locked position as depicted in FIGS. 15 and 17 - 19 , wherein control lever 110 is received in keeper 122 or other structure on outer sash 327 , thereby locking inside sash 310 and outer sash 327 together. Sweep cam 118 of control lever 110 is engaged in locking tab 124 of keeper 122 to provide a locked position. In the locked position, spool 162 remains aligned so that linking member 106 is not under tension and latch-bolt portions 248 of latch-bolts 34 project outwardly into grooves 332 in window frame 334 , thereby preventing tilting of inside sash 310 .
Window 312 may be unlocked by rotating lever 110 to an unlocked position as depicted in FIG. 20 . In the unlocked position, sweep cam 118 of control lever 110 does not engage locking tab 124 of keeper 122 . Once again, latch-bolts 34 are not retracted and project outwardly into grooves 332 to prevent tilting of inside sash 310 . As control lever 110 and cam 158 rotate from the locked position to the unlocked position, cam 158 travels between cam followers 219 without causing gear 160 to rotate.
Generally, cam 158 is shaped and cam followers 219 are shaped and positioned so that control lever 110 has a rotational range of travel between approximately 100° and 160° degrees from the locked position to the unlocked position. In an example embodiment, control lever 110 has a range of rotation of travel of approximately 135° between the locked and unlocked positions. Between the locked and unlocked positions, biasing member 164 biases cam 158 primarily toward a locked or unlocked position. A neutral position exists in which the biasing member 164 acts upon cam 158 such that cam 158 remains substantially stationary between the locked and unlocked positions. For cam 158 to remain in the neutral position, a line between acute corners 158 A,B is substantially perpendicular to flex regions 150 , 152 biasing member 164 . Generally, a neutral position exists at the midpoint between the locked and unlocked positions. The neutral position may, however, include any number of degrees of rotation of travel of control lever 110 between the locked and unlocked position. Generally, this neutral position is considered unfavorable and has been minimized by rounding the corners of cam 158 so as to cause cam 158 to slip past flex regions 150 , 152 of biasing member 164 . Between the locked position and the neutral position, biasing member 164 biases cam 158 toward the locked position.
Generally, cam 160 is shaped and cam followers 219 are shaped and positioned so that control lever 110 rotational range of travel between approximately 15° and 75° from the unlocked position to the tilt position. In an example embodiment, control lever 110 rotates approximately 45° between the unlocked and tilt positions. Between the unlocked and neutral positions, biasing member 164 biases cam 158 toward the unlocked position when rotating control lever 110 to the tilt position.
With window 312 unlocked, inside sash 310 may be tilted inward by rotating lever 110 to a tilt position as depicted in FIG. 21 . As control lever 110 , acute corners 158 A,B of cam 158 engages gear sector 388 of spool 162 causing spool 162 to rotate, thereby applying tension to linking member 106 . The tension on connecting member 106 draws plunger 222 of each tilt-latch assembly 104 inwardly toward actuator assembly 102 , sliding plunger 222 within housing 220 against the bias of primary spring 224 and drawing latch-bolt portion 248 within housing 220 . As leading edge 253 A of latch-bolt portion 248 clears plate portion 294 of plunger-latch 226 , latch spring 228 urges plunger-latch 226 in the direction of outer sash 327 so that plate portion 294 partially blocks aperture 266 . Leading edge 253 A of latch-bolt portion 248 engages plate portion 294 , holding plunger 222 retracted within housing 220 . Trigger portion 298 projects slightly from the outer face 336 of top rail 308 . With control lever 110 and tilt latches 34 in tilt position, inside sash 310 may be tilted inwardly to gain access to the outside of the window. In the tilt position, biasing member 164 biases cam 158 toward the unlocked position.
Once the window cleaning or other operation is completed and it is desired to return inside sash 310 to its operable position, inside sash 310 may be simply tilted back into position. Trigger portion 298 contacts outer sash 327 , urging plunger-latch 226 against the bias of latch spring 228 . When plunger-latch 226 clears leading edge 253 A of latch-bolt portion 248 , primary spring 224 urges plunger 222 in the direction away from actuator assembly 102 , so that latch-bolt portion 248 extends outwardly through aperture 266 and engages in grooves 332 .
In an alternative embodiment of the present invention, top rail 308 is substantially hollow as is typically the case in vinyl window construction. Reinforcing insert 338 fits inside hollow top rail 308 to provide support for the tilt-latch assemblies 104 . Housing 220 of each tilt-latch assembly 104 has spring securing tabs 340 projecting on opposite sides proximate outer end 342 . Each tab 340 is resiliently attached to housing 220 at hinge line 344 . Outer end 346 is normally spaced apart from housing 220 , but is capable of being pressed inwardly into opening 348 in barrel portion 232 Lip 349 extends outwardly around perimeter 349 A of end wall 349 B. Housing 220 further has opposing flats 350 , 352 . Flat 350 has longitudinal ridge 354 defined thereon.
Tilt-latch assembly 104 is received through apertures 356 in top rail 308 and inside reinforcing insert 338 . Insert 338 is preferably made from metal, but may also be made from any other suitably rigid and durable material. Flats 350 , 352 , mate with inside walls 358 , 360 , of reinforcing insert 338 respectively to inhibit undesired rotation of tilt-latch assembly 104 about its longitudinal axis. Longitudinal ridge 354 mates with corresponding groove 362 in inside wall 358 so that tilt-latch assembly 104 is coded for proper orientation. As each tilt-latch assembly 104 is advanced into aperture 356 , tab 340 contacts edge 364 , forcing outer end 346 inwardly. Once outer end 346 clears edge 364 and lip 349 contacts outer surface 366 of top rail 308 , outer end 346 springs outwardly to engage inner surface (not depicted) of top rail 308 to retain tilt-latch assembly 104 in place.
As depicted in FIG. 15 , optional keeper 122 generally includes locking tab 124 defining a finished outer surface 124 A and skirt portion 124 B. Skirt portion 124 B defines recess 124 C for receiving outer wall 118 A of sweep cam 118 . Skirt portion 124 B engages circumferential recess 118 B of sweep cam 118 when sweep cam 118 is rotated to the “locked” position. Openings 122 A may be defined in skirt portion 124 B for receiving fasteners (not depicted) to secure keeper 122 to bottom rail 378 of outer sash 327 at a location adjacent actuator assembly 102 when bottom rail 378 is adjacent top rail 308 of inside sash 310 . | An integrated lock and tilt-latch mechanism for a sliding window including an actuator assembly operably connected by a flexible linking member to at least one tilt-latch mechanism adapted for mounting in a window sash. The actuator assembly includes a control lever that rotates a sweep cam and a selectively rotates a spool, thereby locking or unlocking the sliding window or actuating the tilt-latch mechanism. At least one biasing member causes the control lever to favor locked or unlocked positions over intermediate and tilt positions. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of co-pending U.S. patent application Ser. No. 15/379,777, filed Dec. 15, 2016, which is a continuation of U.S. patent application Ser. No. 14/798,562 (now U.S. Pat. No. 9,560,435), filed Jul. 14, 2015, which is which is a continuation of U.S. patent application Ser. No. 14/631,740 (now U.S. Pat. No. 9,114,923), filed Feb. 25, 2015, which is a continuation of U.S. patent application Ser. No. 14/283,055 (now U.S. Pat. No. 8,995,127), filed May 20, 2014, which is a continuation of U.S. patent application Ser. No. 14/031,700 (now U.S. Pat. No. 8,922,985), filed Sep. 19, 2013, which is a continuation of U.S. patent application Ser. No. 12/560,621 (now U.S. Pat. No. 8,599,547), filed Sep. 16, 2009, which is a division of U.S. patent application Ser. No. 11/456,157 (now U.S. Pat. No. 7,609,512), filed Jul. 7, 2006, which is a continuation-in-part of U.S. patent application Ser. No. 10/937,048 (now U.S. Pat. No. 7,158,376), filed Sep. 8, 2004, which is a continuation-in-part of U.S. patent application Ser. No. 10/645,439 (now U.S. Pat. No. 6,995,976), filed Aug. 20, 2003, which is a continuation of U.S. patent application Ser. No. 10/300,200 (now U.S. Pat. No. 6,646,864), filed Nov. 19, 2002, which claims the benefit of and priority to U.S. Provisional Patent Application Ser. No. 60/335,865, filed Nov. 19, 2001. The entire contents of the above mentioned applications and patents are hereby specifically incorporated by reference in their entireties.
BACKGROUND OF THE INVENTION
[0002] Portable electronic devices (PEDs), such as PDAs, computers, MP3 players, music players, video players, smart phones, GPS receivers, telematics devices, cell phones, satellite phones, pagers, monitors, etc., are being very widely used, and are being deployed in industrial as well as office environments. PEDs are being used in industrial environments for data collection, such as service information on an airplane, or for data delivery such as maps for fire fighters and other emergency personnel. When PEDs are deployed in such industrial applications, the data that is collected and displayed on the PED can be extremely valuable and can be lifesaving.
[0003] The industrial environments impose harsh conditions that typical PEDs are not designed to accommodate. For example, damage can be done to the PED through rough handling and dropping. Further, industrial chemicals, grease, water, dirt, and grime may damage or destroy a functioning PED and inhibit the use of the PEDs valuable data.
[0004] It is common to hold the PEDs inside a protective case for transport. However, PEDs are usually removed for use since most cases used for transport are not interactive. Interactive cases are also useful for non-industrial applications to provide protection for PEDs.
SUMMARY OF THE INVENTION
[0005] In one aspect, a protective cover is disclosed for an electronic device having a capacitance-sensing interactive touch screen display, at least one control button, a camera feature, and an electrical interface. The protective cover includes a protective shell base having an inner surface, an outer surface, and a plurality of side members defining a perimeter of the protective shell base. The protective cover also includes a cushioning member coupled with at least the inner surface of the protective shell base. The cushioning member is configured for cushioning the electronic device when the electronic device is disposed in the protective shell base. The protective cover also includes a first opening defined by the perimeter of the protective shell base. The first opening is configured to align with and expose at least a portion of the capacitance-sensing interactive touch screen display when the electronic device is disposed in the protective shell base. The protective cover also includes a second opening passing through the inner and outer surfaces of the protective shell base and configured to align with the camera feature of the electronic device when the electronic device is disposed in the protective shell base. The protective cover further includes an access port in at least one of the plurality of side members of the protective shell base. The access port is positioned to be proximate the electrical interface of the electronic device when the electronic device is disposed in the protective shell base.
[0006] In another aspect, a protective enclosure for a mobile computing device is provided. The protective enclosure includes a first case member, a second case member, a plurality of pliable areas, an electrical connector, audio headphones, and a headphone cable. The first and second case members each have an exterior surface, and interior surface, and a perimeter portion. The second case member is removably attachable to the first case member with one or more latching mechanisms. The attachment of the second case member to the first case member forms a protective interior of the protective enclosure for receiving the mobile computing device. The plurality of pliable areas are disposed in the first case member and/or the second case member, and each align with a corresponding control button of the mobile computing device. The pliable areas transmit at least a portion of a force applied at an external surface of one of the pliable areas to the corresponding control button of the mobile computing device to actuate the corresponding control button of the mobile computing device when the mobile computing device is in the protective interior of the protective enclosure.
[0007] The electrical connector is attached to the interior surface of the second case member, and is structured to mate with a corresponding electrical connector of the mobile computing device when the mobile computing device is inside the protective enclosure. The audio headphones are connected to the exterior surface of one of the first case member and the second case member via a headphone cable. The headphone cable electrically interconnects the audio headphones to the electrical connector of the protective enclosure such that audio signals generated by the mobile computing device inside the protective interior are transmitted through the electrical connector of the mobile computing device through the electrical connector of the protective enclosure and through the headphone cable to the headphones outside the protective enclosure.
[0008] In another aspect, the disclosure describes a protective case for a portable electronic device, including first and second case portions, a pliable molded surface, an electrical connector, and audio headphones. The first case portion may have an exterior surface, an interior surface, and a perimeter portion. The second case portion may also have an exterior surface, an interior surface, and a perimeter portion, and may be removably attachable to the first case portion to form a protective shell. Such protective shell may include a cavity for the portable electronic device inside the shell, the cavity defined by at least a portion of the interior surface of the first case portion and at least a portion of the interior surface of the second case portion.
[0009] The pliable molded surface may be disposed in an opening of one of the first case portion and the second case portion, and may align with a corresponding control button of the portable electronic device. The pliable molded surface may transmit a mechanical pressure applied at an exterior surface of the pliable molded surface to the control button of the portable electronic device to actuate the control button of the portable electronic device when the portable electronic device is inside the shell.
[0010] The electrical connector may be attached to the interior surface of the first or second case portion, and may mate with an electrical interface of the portable electronic device when the portable electronic device is inside the shell. The audio headphones may have a headphone cable connected to the exterior surface of the first or second case portion. The headphone cable may be electrically interconnected through a wall of the first or second case portion to the electrical connector of the protective case. This interconnection permits electrical audio signals generated by the portable electronic device inside the shell to be transmitted from the electrical interface of the portable electronic device through the electrical connector and through the headphone cable to the headphones.
[0011] In another disclosed aspect a protective case for a portable electronic device may include a protective shell, audio headphones, and a headphone cable. The protective shell may include a first case portion, a second case portion, a pliable surface, and an electrical pass-through. The first case portion and the second case portion may each have an exterior surface and an interior surface. The second case portion may be removably attachable to the first case portion, where attachment of the second case portion to the first case portion forms a protective cavity for the portable electronic device.
[0012] The pliable surface may be disposed in an opening of one of the first case portion and the second case portion. The pliable surface may align with a control feature of the portable electronic device when the portable electronic device is inside the protective cavity. The pliable surface may also be structured to transmit at least a portion of a mechanical force applied at an external surface of the protective shell to the control feature of the portable electronic device to actuate the control feature.
[0013] The electrical pass-through provides electrical access to a headphone jack of the portable electronic device from outside the protective shell when the portable electronic device is inside the protective cavity in the protective shell. The audio headphones are affixed, and electrically connected, to the headphone cable. The headphone cable electrically connects the audio headphones to the headphone jack of the portable electronic device inside the protective shell through the electrical pass-through such that audio signals from the portable electronic device inside the protective shell are conducted to the audio headphones through the headphone cable.
[0014] In yet another example, a protective case for use with a portable electronic device includes a protective shell including a cavity for receiving the portable electronic device and a pliable surface disposed in an opening of the protective shell. The pliable surface being adapted to transmit at least a portion of a mechanical force applied at an external surface of the protective shell to the control feature of the installed portable electronic device to actuate the control feature of the installed portable electronic device. The protective case also includes an electrical pass-through disposed in a wall of the protective shell for accessing an electrical connector of the installed portable electronic device from outside the protective shell and an electrical cable configured to electrically connect a peripheral device to the electrical connector of the installed portable electronic device through the electrical pass-through.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] In the drawings,
[0016] FIG. 1 is a perspective view of an embodiment of the invention shown in the closed position.
[0017] FIG. 2 is a perspective view of an embodiment of the invention shown in the open position.
[0018] FIG. 3 is a perspective view of an embodiment of the invention shown in an exploded state.
[0019] FIG. 4 is a perspective view of an embodiment of the invention shown from the rear.
[0020] FIG. 5 is a front view of an embodiment of the invention, showing a section line.
[0021] FIG. 6 is a section view of an embodiment of the invention.
[0022] FIG. 7 is a detailed view of a section shown in FIG. 6 .
[0023] FIG. 8 is a perspective view of another embodiment comprising a single piece encapsulating cover.
[0024] FIGS. 9 and 9A to 9C show a perspective view of a third embodiment comprising a non-encapsulating snap over cover and various close-up and cross-sectional views.
[0025] FIG. 10 is a perspective view of an embodiment that comprises a belt clip.
[0026] FIG. 11 is a second perspective view of an embodiment that comprises a belt clip.
[0027] FIG. 12 is a perspective view of another embodiment of the present invention of a protective cover for a PED or other device.
[0028] FIG. 13A is a perspective top view of another embodiment of a protective enclosure for a tablet PC.
[0029] FIG. 13B is a view of the protective enclosure lid of FIG. 13A .
[0030] FIG. 14 is a perspective top view of the embodiment of FIG. 13A with an open lid.
[0031] FIG. 15 is a perspective bottom view of the embodiment of FIG. 13A .
[0032] FIG. 16 is a perspective view of the base of the embodiment of FIG. 13A
[0033] FIG. 17 is an exploded view of an embodiment of a protective enclosure for an interactive flat-panel controlled device.
[0034] FIG. 18 is an exploded view of another embodiment of a protective enclosure for an interactive flat-panel controlled device.
[0035] FIG. 19 is an exploded view of another embodiment of a protective enclosure with an open lid for a laptop computer device.
[0036] FIG. 20 is an exploded view of a protective enclosure with an open lid for a laptop computer device positioned inside the enclosure.
[0037] FIG. 21 is a perspective top view of a protective enclosure with a closed lid for a laptop computer device.
[0038] FIG. 22 is a perspective bottom view of the protective enclosure FIG. 21 .
[0039] FIG. 23 is a perspective front view of the embodiment of FIG. 21 .
[0040] FIG. 24 is a perspective end view of the embodiment of FIG. 21 .
[0041] FIG. 25 is a perspective back view of the embodiment of FIG. 21 .
[0042] FIG. 26 is a perspective view of the USB hub.
[0043] FIG. 27 is a perspective view of the USB hub mounted inside the enclosure of FIG.
[0044] FIG. 28 is a perspective view of the USB hub mounted inside the enclosure of FIG. 14 .
DETAILED DESCRIPTION
[0045] FIG. 1 is a perspective view of an embodiment of the invention. Embodiment 100 comprises a rigidly molded front case 102 and rear case 104 . An overmolded grommet 106 forms a receptacle for stylus 108 and also aids in sealing membrane 110 . A flexible hand strap 112 attaches to the rear case 104 . A hinge 114 joins front case 102 and rear case 104 . A ring 124 for a lanyard is shown as an integral feature of rear case 104 .
[0046] Embodiment 100 is designed to hold a conventional personal digital assistant (PED) in a protective case. A PED, such as a Palm Pilot, Handspring Visor, Compaq Ipaq, Hewlett Packard Jornada, or similar products, use a touch screen for display and data entry. The touch screen display comprises either a color or black and white liquid crystal display with a touch sensitive device mounted on top of the display. The display is used for displaying graphics, text, and other elements to the user. The touch screen is used with a stylus 108 to select elements from the screen, to draw figures, and to enter text with a character recognition program in the PED. The stylus 108 generally resembles a conventional writing implement. However, the tip of the writing implement is a rounded plastic tip. In place of a stylus 108 , the user may use the tip of a finger or fingernail, or a conventional pen or pencil. When a conventional writing implement is used, damage to the touch screen element may occur, such as scratches.
[0047] For the purposes of this specification, the term PED shall include any electronic device that has a touch screen interface. This may include instruments such as voltmeters, oscilloscopes, logic analyzers, and any other hand held, bench top, or rack mounted instrument that has a touch screen interface. Hand held devices, such as cell phones, satellite phones, telemetric devices, and other hand held devices are also to be classified as PEDs for the purposes of this specification. The term PED shall also include any computer terminal display that has a touch screen interface. These may comprise kiosks, outdoor terminal interfaces, industrial computer interfaces, commercial computer interfaces, and other computer displays. Additionally, the term PED may comprise barcode scanners, hand held GPS receivers, and other handheld electronic devices. The foregoing description of the term PED has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed, and other modifications and variations may be possible in light of the teachings of this specification.
[0048] In addition, the PEDs typically have a handful of additional buttons as part of the user interface. These buttons are generally on the front of the device, near the touch screen element. The additional buttons may be used as shortcut buttons to instantly call up a certain program on the PED, may comprise a method of scrolling, may be used to select items from a list, or may have any function that the designer of the PED software may assign to the button or set of buttons. The button size, layout, and function may vary for each manufacturer and model of PED.
[0049] Further, PEDs typically have at least one method of connecting to another computer. This may be through a direct electrical connection, such as through a wire cable or fiber optic, or through another medium such as infrared communication or through a radio communication.
[0050] Additionally, the PEDs typically have an electrical source. The electrical source may be a rechargeable or non-rechargeable battery or solar cells. The electrical source may be a remote source of electricity that is transmitted to the PED through a wire cable or through other methods of electrical transmission.
[0051] Further, PEDs may have indicator lights, such as status lights for power, communication, battery status, or other functions. The lights may be located on any of the sides of the PED and may be viewable on one or more sides.
[0052] Front case 102 and rear case 104 form a protective cover for the PED. The protective cover may be designed for rugged industrial use, recreational use, commercial use, or many other uses. An industrial use may require the protective cover to be watertight, chemically resistant, protect the unit when dropped, and be crush proof. A typical application may be for fire fighters to use a PED for a display of maps for directions to an emergency scene or for a building plan at the scene of a fire. Another example may be a maintenance mechanic in a chemical plant using a PED to record maintenance records in the plant that processes. A recreational use may require the cover to be watertight, afford some protection against dropping and being crushed, float in water, and be dust resistant. A recreational use may be to take the PED during kayaking, diving, or other water sport activity. Further, the case may be used when the PED is taken camping, hiking, or other outdoor activity. A commercial use may additionally require the protective cover to be elegant, but may also require the cover to be replaceable so that scratches and other signs of wear and tear can be easily and cheaply replaced.
[0053] The protective cover for the PED may take on many embodiments. The embodiment 100 comprises a front case 102 and rear case 104 that are joined by a hinge 114 and a clasp mechanism that is on the side of the cases opposite the hinge 114 . Other embodiments may have a small door into which the PED slides, or the protective cover may not completely enclose the PED and only cover the face where the user interface exists, leaving one or more sides of the PED exposed. Those skilled in the art may use other designs of protective covers without deviating from the scope and intent of the present invention.
[0054] The protective cover may be constructed of rigid plastic, metal, flexible rubber, or any other type of material that could be adapted to afford the protection of the PED desired for the application. For example, a metal cover may be used in an application where an elegant style is necessary but watertightness is not. A flexible rubber cover may be selected for an application in a wet environment. A rigid plastic cover may be selected for an application where dropping the PED is a concern. Those skilled in the art may use other types of materials and constructions without deviating from the spirit of the present invention.
[0055] The PED may be mounted in the protective cover using many different mounting techniques. For example, the PED may be mounted using open or closed cell foam inserts in the protective cover. In another embodiment, the PED may be mounted by attaching the PED to the cover with a fastener. In another embodiment, the PED may be mounted by snapping into the protective waterproof cover. In another embodiment, the PED may be held in place by resting in molded features of two halves of a protective case that clamps onto the PED. Those skilled in the art may use other types of locating and holding mechanisms without deviating from the spirit of the present invention.
[0056] The overmolded grommet 106 of the present embodiment is constructed by injection molding a thermoplastic polymerized rubber (TPR) over the front case 102 . The grommet 106 has molded features 116 and 118 adapted to retain the stylus 108 . Features 116 and 118 capture the stylus 108 during transportation, but allow the user to remove the stylus 108 to operate the PED. In other embodiments of the present invention, the stylus 108 may be constrained to the PED with a tether or lanyard, or the constraining features may be incorporated into other components that make up the protective cover. Further, the stylus 108 may not be present in the embodiment, rather, the PED be adapted to be used with the user's fingernail or with another implement similar to the stylus 108 .
[0057] The membrane 110 of the present embodiment is constructed by thermoforming a sheet of thin plastic. The plastic is selected to be thin enough that the deformation of a stylus conducts the touch to the touch screen, but thick enough to have enough rigidity that the stylus does not catch and rip the membrane. Additionally, the membrane 110 should have enough thickness to endure scratches and other wear and tear without breaking and sacrificing the protective function. Polyvinylchloride material at 0.010 inches to 0.015 inches thickness gives acceptable results. Alternatively, membrane 110 may be constructed by injection molding or other methods. Alternative materials may be used by those skilled in the art to achieve the same results while maintaining within the spirit and intent of the present invention.
[0058] The membrane 110 in the present embodiment may be translucent or at least partially transparent, so that the images displayed on the PED may be visible through the membrane 110 . The membrane 110 may be tinted or colorized in some applications. For example, a protective cover designed as a decorative cover may incorporate a colorized membrane 110 . Further, the membrane may be selectively colorized and the opaqueness may vary. For example, the protective membrane may be printed or painted in the areas not used for the touch screen. A printing process may incorporate a logo, graphics, or labeling for individual buttons for the PED. The printing process may further incorporate features, such as text or graphics, that are used by the software on the PED for a purpose such as simplifying data input or for designating an area on the touch screen for a specific function, such as a help function. The printing or painting processes used on the membrane 110 may be purely decorative and may be for aesthetic purposes only. The printing process may also comprise logos or graphics for the brand identity of the PED cover. Other processes, such as colorizing the raw material for the membrane 110 or adding other components to the raw material, such as metal flakes or other additives, may be used to change the optical features of the membrane 110 .
[0059] The optical performance of the membrane 110 may be changed or enhanced by changing the texture of the area of the touch screen. For example, the membrane may be frosted on the outside to hide scratches or may be imprinted with a lens or other features that change the optical characteristics of the membrane 110 . The membrane 110 may have optical features that are used in conjunction with the software of the PED. For example, all or a portion of the membrane may comprise a lens that magnifies an image to a user. When the user touches the image on the membrane 110 and the touch is transferred to the touch screen, the software in the PED may have to compensate for the positional differences between the image and actual area that was touched by the user. In another example, if a specific portion of the membrane 110 had a specific optical characteristic, the software of the PED may be constructed to display a specific graphic for the area for an intended effect.
[0060] The membrane 110 in the present embodiment has a recessed portion 120 and a raised portion 122 . The recessed portion 120 may be adapted to press flat against the touch screen area of a specific PED. The raised portion 122 may be adapted to fit over an area of the specific PED where several buttons are located.
[0061] The raised portion 122 allows the user to operate the buttons on the PED. The raised portion 122 is adapted such that the buttons on the PED are easily operated through the protective membrane 110 . The raised portion 122 may have special features to aid the user in pressing the buttons. For example, the raised portion 122 may comprise a dimpled area for the user's finger located directly over the button. Further, a feature to aid the user may comprise a section of membrane 110 defined by a thinner area around the section, enabling the user to more easily deflect the section of membrane over the button. The area of thinner material may comprise a large section or a thin line. Further, tactile elements, such as small ribs or bumps may be incorporated into the membrane 110 in the area of the buttons so that the user has a tactile sensation that the user's finger is over the button. The tactile element may be particularly effective if the button was a power switch, for example, that turned on the PED.
[0062] The configuration of the membrane 110 may be unique to each style or model of PED, however, the front case 102 and rear case 104 may be used over a variety of PEDs. In the present embodiment, the changeover from one PED variety to another is accomplished by replacing the membrane 110 without having to change any other parts. The present embodiment may therefore be mass-produced with the only customizable area being the membrane 110 to allow different models of PEDs to be used with a certain front case 102 and rear case 104 .
[0063] The hand strap 112 in the present embodiment allows the user to hold the embodiment 100 securely in his hand while using the PED. The hand strap 112 may be constructed of a flexible material, such as rubber or cloth webbing, and may have an adjustment, such as a buckle, hook and loop fastener, or other method of adjustment. In other embodiments, a hand strap may be a rigid plastic handle, a folding handle, or any other method of assisting the user in holding the embodiment. Further, the embodiment may be adapted to be fix-mounted to another object, like a piece of machinery, a wall, or any other object. A fix-mounted embodiment may have other accoutrements adapted for fixed mount applications, such as receptacles for a stylus adapted to a fix-mount, specialized electrical connections, features for locking the PED inside the case to prevent theft, or designs specifically adapted to shed water when rained upon.
[0064] FIG. 2 illustrates a perspective view of the embodiment 100 shown in an open position. The front case 102 and rear case 104 are shown open about the hinge 114 . Membrane 110 is shown installed into gasket 106 , and the recessed portion 120 and raised portion 122 of membrane 110 is illustrated looking from the inside of the case. The clasp mechanisms are not shown in this illustration. Hand strap 112 is shown attached to rear case 104 .
[0065] FIG. 3 illustrates a perspective view of the embodiment 100 shown in an exploded state. The hand strap 116 attaches to the rear cover 104 . The overmolded grommet 106 holds the stylus 108 and is attached to front cover 102 . The membrane 110 attaches to the grommet 106 and is held in place with an o-ring 302 .
[0066] FIG. 4 illustrates a perspective view of the embodiment 100 shown from the rear. The hand strap 116 is shown, along with rear cover 104 and front cover 102 . The stylus 108 is shown inserted into the overmolded grommet 106 .
[0067] FIG. 5 illustrates a top view of the embodiment 100 . The front cover 102 , membrane 110 , stylus 108 , and hinge 114 are all visible.
[0068] FIG. 6 illustrates a section view of the embodiment 100 taken through the section line shown in FIG. 5 . The front cover 102 , rear cover 104 , overmolded gasket 106 , stylus 108 , membrane 110 , hand strap 112 , and o-ring 302 are all shown hatched in this view.
[0069] FIG. 7 illustrates a detail view of the embodiment 100 shown in FIG. 6 . Front case 102 and rear case 104 are joined at hinge 114 . Overmolded gasket 106 traps membrane 110 and o-ring 302 locks membrane 110 in place. Overmolded gasket 106 may be formed by molding thermoplastic polymerized rubber over the front cover 102 .
[0070] The replacement of the membrane 110 is accomplished by removing o-ring 302 , pushing the membrane 110 from the overmolded gasket 106 , snapping a new membrane 110 into place, and replacing the o-ring 302 . The ease of replacement of the present embodiment allows a user to quickly replace a damaged membrane 110 , allows a user to upgrade their case to a newer model PED, and may allow a user to select from various membranes 110 for the particular application. One embodiment may have a single case packaged with a small variety of several types of membranes 110 . In such an embodiment, the user may purchase the packaged set, select the membrane 110 that suits the user's particular PED, and install the selected membrane 110 with ease.
[0071] The protective cover of the present invention may have direct connections through the cover for connecting through the case. Such a connection is known as pass through. The connections may be for power, communication, heat dissipation, optical transmissions, mechanical motion, or other reasons.
[0072] Electrical connections may require an insulated metal conductor from the PED through the wall of the protective cover so that a flexible cable may be attached or so that the PED in its protective case may be placed in a cradle for making the electrical connection. Inside the protective cover, the electrical connections may be made with a flexible cable that is plugged into the PEDs electrical connector before the PED is secured in the protective cover. Alternatively, a fixed connector may be attached to the protective cover and the PED is slid into contact with the fixed connector. Another embodiment may be for a compliant, yet fixed mounted electrical connector to be rigidly mounted inside the protective cover. A compliant, yet fixed mounted electrical connector 1830 may comprise spring loaded probes, commonly referred to as pogo pins. Another embodiment may comprise spring fingers that engage the PEDs electrical contacts. On the outside of the protective cover, the electrical contacts may be terminated into a fix-mounted connector adapted to receive a cable from a computer. The connector may be designed to receive a cable that plugs directly into the PED or it may be adapted to receive a different connector. Further, the electrical connection to the PED may be permanently attached to a cable that extends out of the protective cover. Another embodiment may be to have a small trap door that opens in the protective cover to allow access to the electrical connections. While the trap door exposes the PED to the elements the cover is designed to protect against, a direct electrical connection may eliminate a potential cabling connection problem. Connections for fiber optics can be handled in similar fashions as the electrical connections. An embodiment with a power connection may comprise the use of inductive coils, such as inductive coil 1840 , located in proximity to each other but on opposite sides of the protective cover. Those skilled in the art of may devise other embodiments for connecting through the protective cover without deviating from the scope and intent of the present invention.
[0073] Through the air communications, such as infrared and over the air radio frequency (RF) communications may pass through the protective cover. The material for the front case 102 and rear case 104 may be selected to be clear plastic, such as polycarbonate. The infrared transceiver of the PED can communicate through a clear plastic case to another infrared transceiver outside of the case. Further, the appropriate selection of material for the protective case can thereby enable various RF transmissions, such as cellular phone communications or other wireless communication protocols.
[0074] An infrared transmission through the protective case of an embodiment of the invention may be accomplished by making the entire protective case out of a clear material. Alternatively, a selected area of the protective case may be clear while the remainder of the case is opaque. The selected area may be constructed of a separate piece that allows the infrared light through the protective case. Alternatively, the selected area may be constructed of a portion of the protective case that was manufactured in a way so as not to be opaque, such as selectively not painting or plating the area of a plastic protective case. Further, the clear material through which the transmission occurs may be tinted in the visual spectrum but be translucent or at least partially transparent in the infrared spectrum of the device.
[0075] A protective case may allow RF transmissions to and from the PED while the case is closed. Such a case may be constructed of a non-metallic material. In some embodiments, the material of the protective case may be tuned to allow certain frequencies to pass through the protective cover and tune out other frequencies, through loading the material used in the protective cover with conductive media or through varying the thickness of the case and other geometries of the case in the area of the PED transmission and reception antenna.
[0076] In a different embodiment, it may be desirable to shield the PED from outside RF interference. In this case, the protective cover may be a metallic construction or may be plastic with a metallized coating. Further, membrane 110 may have a light metallized coating applied so that membrane 110 is slightly or fully conductive. An application for such an embodiment may be the use of the PED in an area of high RF noise that may interfere with the operation of the PED, or conversely, the use may be in an area that is highly susceptible to external RF interference and the PEDs RF noise may be interfering with some other device.
[0077] The PED may be equipped with a camera or other video capture device. A protective cover may have provisions to allow a clear image to be seen by the video capture device through the case. Such provisions may include an optically clear insert assembled into the protective case. Other embodiments may have a sliding trap door whereby the user of the PED may slide the door open for the camera to see. Additionally, other embodiments may comprise a molded case that has an optically clear lens integrally molded. Such an embodiment may be additionally painted, plated, or overmolded, with the lens area masked so that the painting, plating, or overmolding does not interfere with the optics of the lens.
[0078] An optically clear area may be used for a barcode scanner portion of a PED to scan through the case to the outside world. In such an embodiment, a barcode scanner may be protected from the elements while still maintaining full functionality in the outside world.
[0079] The PED may have indicator lights that indicate various items, such as power, battery condition, communication, and other status items. The indicator lights may be in positions on the PED that are not readily viewable through the protective membrane 110 . The indicator lights may be made visible through the protective case by using light pipes that transmit the light from the PEDs status light to the outside of the protective case. Such light pipes may be constructed of clear or tinted plastic, or other translucent or semi-transparent material. The light pipes may be formed as an integral feature to the protective case or may be separate parts that are formed separately and assembled to the protective case.
[0080] The PED may have a speaker or other element that makes noise and/or the PED may have a microphone for receiving audio signals. The speaker may be an audio quality device for reproducing sound or it may be a simple buzzer for indicating various functions of the PED. The microphone may be an audio quality device or it may be a low performance device. Special provisions may be made for transmitting sound through a protective case. Such provisions may range from a single hole in the case to a tuned cavity that would allow sound to pass through with minimum distortion. Other embodiments may include a transmissive membrane adapted to allow sound to pass through the protective case with a minimum of distortion. Such membranes may be located near the speaker and microphone elements of the PED. Such membranes may be watertight membranes known by the brand name Gore-Tex.
[0081] The PED may generate heat during its use and provisions for dissipating the heat may be built into the protective cover. A heat-dissipating device may be integral to the protective cover or may comprise one or more separate parts. For example, a metallic protective cover may be adapted to touch the PED in the area of heat generation and conduct the heat outwardly to the rest of the protective cover. The protective cover may thereby dissipate the heat to the external air without overheating the PED. In another example, a separate heat sink may be applied to the PED and allowed to protrude through a hole in the protective cover. The heat sink may thereby transfer the heat from the PED to the ambient environment without overheating the PED. The heat sinks may be attached to the PED with a thermally conductive adhesive. Other embodiments may include vent holes for heat dissipation and air circulation.
[0082] The PED may have a button that may not be located underneath the membrane 110 . An embodiment may include a flexible, pliable, or otherwise movable mechanism that may transmit mechanical motion from the outside of the case to a button on the PED. Such an embodiment may have a molded dimpled surface that is pliable and allows a user to activate a button on a PED by pressing the dimpled surface. Another embodiment may have a rigid plunger that is mounted on a spring and adapted to transmit the mechanical movement from the exterior of the case to a button on the PED. The buttons on the PED may be located on any side of the PED and an embodiment of a case may have pliable areas adapted to allow the user to press buttons that are not on the front face of the PED.
[0083] FIG. 8 is an illustration of embodiment 800 of the present invention wherein the PED 802 is encapsulated by a protective cover 804 . The installation of the PED 802 is to slide PED 802 into the opening 808 , then fold door 806 closed and secure with flap 810 , which is hinged along line 812 . Areas 814 and 816 may comprise a hook and loop fastener system or other fastening device. Recessed area 818 is adapted to fit against touch screen 820 of PED 802 .
[0084] Embodiment 800 may be comprised of a single molded plastic part that may be very low cost. As shown, embodiment 800 may not be completely weathertight, since the door 806 does not completely seal the enclosure. However, such an embodiment may afford considerable protection to the PED 802 in the areas of dust protection, scratch protection, and being occasionally rained upon. Further, the low cost of the embodiment 800 may be changed often during the life of the PED 802 .
[0085] Embodiment 800 may have custom colors, logos, or designs that allow a user to personalize their PED with a specific cover that is suited to their mood or tastes. The colors, logos, and designs may be integrally molded into the cover 804 . Alternatively, different colors, logos, and designs may be applied in a secondary operation such as printing, painting, plating, or other application process.
[0086] FIG. 9 is an illustration of embodiment 900 of the present invention wherein a decorative cover 902 is snapped over a PED 904 . The ends 906 and 908 snap over the PED ends 910 and 912 as an attachment mechanism for cover 902 to PED 904 . Recessed area 914 is adapted to fit against touch screen 916 .
[0087] Embodiment 900 may be a cover for decorative purposes only, or may be for protective purposes as well. Cover 902 may be emblazoned with logos, designs, or other visual embellishments to personalize the PED 904 . The colors, logos, and designs may be integrally molded into the cover 904 . Alternatively, different colors, logos, and designs may be applied in a secondary operation such as printing, painting, plating, or other application process. For example, FIGS. 9A-9C illustrate close-up ( 9 A, 9 B) and cross-sectional ( 9 C) views of the cover 902 in which the material of the cover 902 may incorporate various additives, plating, coating, etc. FIG. 9A illustrates an embodiment in which metal flakes 920 are included in the material from which the cover 902 is formed. The drawing is not to scale, and it will be appreciated by those in the art that the metal flakes may take any shape or size, including very small. FIG. 9B illustrates an embodiment that incorporates fibers 930 such as glass fibers, carbon fibers, metal fibers, polyamide fibers, and mixtures thereof. Those having ordinary skill in the art will appreciate that the size and orientation of the fibers may vary. FIG. 9C is a cross-sectional view of an protective cover embodiment, such as shown in FIG. 9 , that incorporates a coating 940 , such as a metallic coating that coats an exterior portion of the protective cover 902 . The coating, plating, or painted material, including metallic coating, may be implemented in one or several of a range of thicknesses. Although not shown specifically, one of ordinary skill in the art may appreciate that a coating such as shown in FIG. 9C may itself incorporate metal flakes, fibers, and/or other additives. Those of skill in the art will appreciate that a coating may alternatively or additionally be applied to an interior portion of the cover 902 . In some instances the additives and/or coatings may provide shock absorption characteristics to the cover. Although the close-up and cross-sectional views provided in FIGS. 9A-9C are shown in association with decorative cover 902 of FIG. 9 , it will be appreciated that the construction material of other embodiments disclosed herein may employ flakes, fibers, coatings, and other additives in like manner.
[0088] Embodiment 900 may be attached by snapping the cover 902 onto PED 904 . Special provisions in the case of PED 904 may be provided for a snapping feature of cover 902 , or cover 902 may be adapted to hold onto PED 904 without the use of special features in PED 904 .
[0089] The features used to secure cover 902 to PED 904 may be any mechanism whereby the cover 902 can be secured. This includes snapping, clamping, fastening, sliding, gluing, adhering, or any other method for securing two components together.
[0090] FIG. 10 illustrates a perspective view of an embodiment of a receiver 1002 for holding the protective case 100 . The protective case 100 is held into receiver 1002 in such a manner that the touch screen display is facing into the receiver 1002 , to afford the touch screen display with protection.
[0091] FIG. 11 illustrates a perspective view of the embodiment of a receiver 1002 shown from the opposite side as FIG. 10 . Receiver 1002 is comprised of a back 1102 , a belt clip mechanism 1104 , and four clip areas 1106 , 1108 , 1110 , and 1112 . The protective case 100 is placed into the receiver 1002 by inserting one end into the receiver, then rotating the protective case 100 into position such that the snapping action of clip areas 1106 , 1108 , 1110 , and 1112 are engaged to hold protective case 100 securely.
[0092] Receiver 1002 may be adapted to clip onto a person's belt or may be adapted to be mounted on a wall or other location where the PED may be stored. The orientation of the protective case 100 is such that the touch screen element of the PED is protected during normal transport and storage, since the touch screen interface is facing the back 1102 of the receiver 1002 .
[0093] Receiver 1002 may be made of compliant plastic that allows the clip areas 1106 , 1108 , 1110 , and 1112 to move out of the way and spring back during insertion or removal of the protective case 100 . In the present embodiment, receiver 1002 may be constructed of a single part. In alternative embodiments, receiver 1002 may be constructed of multiple parts and of multiple materials, such as a metal back with spring loaded clips. In other embodiments, special features may be included in the protective case 100 where the receiver 1002 may engage a special feature for securing the protective case 100 .
[0094] FIG. 12 illustrates an embodiment 1200 of the present invention of a protective cover for a PED or other device. A rigid front cover 1202 and a rigid rear cover 1204 are held together with a series of latches 1206 , 1208 , 1210 , and 1212 . The protective membrane 1214 protects the touchscreen of the enclosed PED. A folding rigid cover 1216 operates as a rigid shield to prevent the membrane 1214 from any damage. The stylus holder 1220 is formed from an overmolded flexible material in which the membrane 1214 is mounted.
[0095] Embodiment 1200 illustrates yet another embodiment of the present invention wherein a rigid protective cover may be used to contain and protect an electronic device, but provide full usable access to a touchscreen. The protective membrane 1214 and case may be watertight in some embodiments.
[0096] FIG. 13A illustrates an embodiment of a protective enclosure 1300 that encloses and protects a tablet PC 1302 . PEDs that have touch screens, as described above, have an interactive flat-panel control, i.e., the touch screen display. Tablet PCs are portable electronic computing devices that have a high-resolution interactive flat-panel control that accepts smooth stylus strokes such as handwriting. The embodiment of FIG. 13A is crush-resistant, impact-resistant, watertight, and simultaneously allows interactive stylus strokes and other sensitive user inputs to be accurately and easily transmitted through a protective screen membrane 1306 to the interactive flat-panel control of tablet PC 1302 .
[0097] A watertight and shock-absorbing foam cushion 1310 may be fixed and sealed to the underside of the lid 1304 around the interactive flat-panel control opening. The protective screen membrane 1306 is fixed and sealed to the shock-absorbing foam cushion 1310 . The shock-absorbing foam cushion 1310 maintains the water tightness of the enclosure. The cushion 1310 also cushions the flat-panel control of the tablet PC 1302 and protects it against breakage if the enclosure and tablet PC are dropped or otherwise subjected to shock. In accordance with the embodiment of FIG. 13A , the shock-absorbing foam cushion 1310 has a thickness of approximately 0.25 inches and extends approximately 0.060 inches below the underside of the interactive flat-panel control opening of the lid 1304 . One source of suitable watertight shock-absorbing foam is E.A.R. Specialty Composites of 7911 Zionville Rd., Indianapolis, Ind., 46268. Cushion 1310 allows the protective screen membrane to move a distance of up to 0.125 inches during an impact to the enclosure or when pressure is applied to protect membrane 1306 while pushing the tablet PC control buttons 1308 or writing on the interactive flat-panel control with a stylus through the membrane. The shock-absorbing foam cushion 1310 also pushes the protective screen membrane 1306 flatly against the surface of the interactive flat-panel control of the tablet PC 1302 so that sensitive user stylus strokes and other inputs are accurately transmitted. The pressure of the cushion 1310 on the protective screen membrane 1306 which holds the protective screen membrane 1306 flatly against the interactive flat-panel control of the tablet PC 1302 also keeps display images, viewed through the protective screen membrane, clear and distortion-free. In embodiments of the protective enclosure to protect a touch-screen device, the protective membrane may be adjacent to the touch screen but does not exert mechanical pressure on the touch screen so that mechanical inputs such as style strokes are sensed only when intended. In embodiments of the protective enclosure to protect a tablet PC that has an RF stylus or to protect a handheld device that a capacitance-sensing interactive flat-panel control, the protective membrane may be pressed flat against the interactive flat-panel control which allows undistorted viewing but does not adversely affect the control since the interactive control uses capacitance or radio frequencies for interactive input instead of mechanical pressure.
[0098] The protective screen membrane 1306 in the embodiment of FIG. 13A is at least partially transparent and has a thickness of approximately 0.010 inches. The thickness of the protective screen membrane 1306 should be typically in the range of 0.001 inches to 0.020 inches so that stylus strokes on the upper surface of protective screen membrane 1306 are transmitted accurately to the interactive flat-panel control of the tablet PC 1302 . Likewise, protective screen membrane 1306 may be flexible or semi-rigid and may be made of polyvinylchloride or other suitable transparent thermoplastic, such as, for example, polyvinylchloride, thermoplastic polycarbonate, thermoplastic polypropylene, thermoplastic acrylonitrile-butadiene-styrene, thermoplastic polyurethane, which has a hardness and texture that permits the stylus to smoothly glide across the surface without skipping, grabbing, or catching against the surface. Some tablet PCs utilize a stylus which transmits strokes to the PC by way of radio frequency transmission. Protective screen membrane 1306 may be made of a rigid, clear, engineered thermoplastic such as, for example, thermoplastic polycarbonate or other thermoplastics as described above, for enclosing a tablet PC. A protective screen membrane 1306 that is rigid may include watertight access ports that allow operation of mechanical buttons or switches of the tablet PC 1302 , such as, for example, control buttons 1308 . The watertight access ports may include holes that have a moveable watertight plug, or any type of watertight button or lever. Protective screen membrane 1306 may include an anti-glare coating or can be made with an anti-glare texture so that display images are clearly viewable without distortion through the protective screen membrane 1306 .
[0099] In the embodiment of FIG. 13A , the lid 1304 of the protective enclosure 1300 may have an external stylus holder 1324 that securely holds a stylus used with the tablet PC 1302 .
[0100] As described above with respect to FIG. 1 , the lid 1304 and the base 1312 may have air-permeable watertight vents 1318 , 1326 that permit the cooling fans of the tablet PC 1302 to force air exchange to dissipate heat by convection so that the tablet PC 1302 does not overheat. Watertight vents 1318 , 1326 may comprise holes in the lid 1304 and base 1312 that are made watertight by covering and sealing the holes with an air-permeable watertight membrane such as, for example, a fabricated expanded polytetrafluoroethylene (ePTFE) membrane. One source of expanded polytetrafluoroethylene (ePTFE) membranes is W.L. Gore & Associates, Inc. of 555 Papermill Road, Newark, Del., 19711.
[0101] The embodiment of FIG. 13A may also comprise a pod door 1322 that allows access to table PC interfaces such as, for example, PCMCIA or Smart Card slots. The pod door 1322 is attached to the lid 1304 so that it may be removed or opened. In the embodiment of FIG. 13A , the pod door 1322 is hingedly connected to a portion of the base 1312 at a location of the base 1312 that has an opening that allows access to the tablet PC interfaces. The opening can be covered by a watertight seal 1320 , such as, for example, an O-ring that is part of pod door 1322 .
[0102] The underside of the lid 1304 also has a watertight seal, such as an O-ring, so that when compound latches 1328 , 1330 , 1332 , and 1334 are closed, the O-ring or seal of the lid 1304 forms a watertight seal against the base 1312 . The protective enclosure 1300 protects the tablet PC 1302 from water and dust intrusion sufficient to comply with Ingress Protection (IP) rating of IP 67, i.e., the protective enclosure totally protects the enclosed tablet PC from dust and protects the enclosed tablet PC from the effects of immersion in one meter of water for 30 minutes.
[0103] The protective enclosure of the embodiment of FIG. 13A may further comprise protective overmolding 1316 attached to the lid 1304 . A similar overmolding may be attached to the base 1312 . The protective overmolding 1316 may be made of material that is easily gripped in slippery conditions and provides additional shock absorption such as, for example, rubber or silicone. The protective overmolding 1316 extends above the surface of the lid in pre-determined areas to provide protrusions that are easily gripped even in slippery conditions. The protective enclosure of the embodiment of FIG. 13 may further comprise watertight plugs such as access port plug 1314 that fit snugly into openings in the base 1312 that provide access to various interfaces, connectors, and slots of the tablet PC 1302 .
[0104] FIG. 13B illustrates a shell lid 1304 of the embodiment of FIG. 13A . Shell lid 1304 and base 1312 may be made of impact/crush resistant material such as glass-fiber reinforced engineered thermoplastic, such as for example, glass reinforced polycarbonate. Alternatively, the shell lid 1304 and shell base may be made of thermoplastic polycarbonate, thermoplastic polypropylene, thermoplastic acrylonitrile-butadiene-styrene, and thermoplastic compositions containing one or more thereof, or other engineered thermoplastics that provide a shock-resistant and impact resistant shell may be used. The engineered thermoplastics may be reinforced with glass fibers, carbon fibers, metal fibers, polyamide fibers, and mixtures thereof. Shell lid 1304 may be further reinforced with stiffeners 1334 , 1336 , 1338 , 1340 that are integrally embedded into the shell lid around the perimeter of an opening in the shell that is directly over the interactive flat-panel control portion of the tablet PC. The stiffeners may be made of steel or other hard material so that the stiffeners provide additional strength and prevent flexing of the lid 1304 which enhances the watertightness and the impact/crush resistance.
[0105] FIG. 14 is an illustration of the embodiment of FIG. 13A with the lid 1404 detached from the base 1412 . To protect the tablet PC 1402 using the protective enclosure 1400 , the tablet PC 1402 is disposed to fit snugly into the base 1412 . The lid is oriented so that hooks 1436 , 1438 area aligned with pin 1440 that is connected to a portion of the base 1412 and the lid is closed so that hooks 1436 , 1438 are retained by pin 1440 . Compound latches 1428 , 1430 , 1432 , and 1434 are then snapped onto the lid so that the lid is compressed tightly against the base providing a watertight seal.
[0106] FIG. 15 is a bottom view of the embodiment of FIG. 13 . The base 1516 of protective enclosure 1500 includes watertight vents such as watertight vent 1506 for air exchange to permit heat and sound dissipation from the enclosed tablet PC while at the same time maintaining watertightness.
[0107] Pod release knobs 1512 , 1518 are attached to the base 1516 so that the knobs can be rotated clockwise to securely wedge against an edge of pod door 1522 to close the pod door 1522 tightly against a rim around the pod opening in base 1516 to create a watertight seal. Knobs 1512 , 1518 can be rotated counter-clockwise to release pod door 1522 to access the interfaces of the tablet PC covered by pod door 1522 .
[0108] To provide additional protection against mechanical shock, heavy-duty corner bumpers such as bumper 1504 may be securely attached to the corners of base 1516 .
[0109] As shown in FIG. 15 , an adjustable heavy-duty handle may be attached to the base 1516 of the protective enclosure 1500 to allow easy and reliable transportation of the protective enclosure 1500 that encloses a tablet PC. In some circumstances, it is convenient to hold the protective enclosure using hand strap 1514 that is made of strong slightly stretchable fabric. Hand strap 1514 attaches to four points of the base 1516 to that a user's hand or wrist can be inserted along the either the longer or shorted length on the protective enclosure 1500 and enclosure tablet PC. Hand strap 1514 may be made of neoprene or other strong stretchable material to securely hold the protective enclosure to the user's arm even in slippery conditions. The protective enclosure may further include a neck strap to provide a comfortable solution for using the tablet PC while standing.
[0110] FIG. 16 illustrates a top view of the protective enclosure base 1600 . Watertight vents such as watertight vent 1616 allow air exchange for heat dissipation and sound transmission from an enclosed tablet PC. Seal rim 1614 is an integrally formed part of the protective enclosure 1600 which is compressed against an O-ring in the protective enclosure lid to provide a watertight seal when compound latches 1628 , 1630 , 1632 , and 1634 are closed onto the lid.
[0111] Internal bumpers 1602 , 1604 , 1608 , 1610 attach to the interior corners of protective enclosure base 1600 to provide cushion and mechanical shock protection to an enclosed tablet PC. The L-shape and non-solid interior of internal bumpers 1602 , 1604 , 1608 , 1610 allows the bumpers to deflect and absorb the shock if the enclosed tablet PC is dropped or otherwise subjected to mechanical shock. The protective enclosure provides shock absorption sufficient to meet MIL-STD 810F, Method 516.5, Procedure 4, which is a Transit Drop Test. In the Transit Drop Test, the protective enclosure encloses a tablet PC or a mass equivalent to a tablet PC. The protective enclosure is sequentially dropped onto each face, edge, and corner for a total of 26 drops over plywood from a height of 48 inches. The protective enclosure is visually inspected after each drop and a functional check for leakage is performed after all drops are completed.
[0112] Some tablet PCs have a docking connector disposed on the underside of the tablet PC so that the tablet PC can connect to power and signals. For example, emergency vehicles such as ambulances, fire trucks, or patrol cars, may have a docking station installed near the driver's seat onto which the driver may dock a tablet PC. The embodiment of protective enclosure base 1600 , as illustrated in FIG. 1 , may comprise a docking connector channel 1624 that is recessed with respect to the upper surface of the base that allows a docking connector to run from a docking connector that is disposed in the center underside of the tablet PC to access port 1626 . Alternatively, a docking pass-through connector 1620 may be made an integral and watertight part of the protective enclosure base 1600 so that the tablet PC docking connector attaches to the docking pass-through connector 1620 which, in turn, connects to the docking station in substantially the same manner as an unenclosed tablet PC.
[0113] FIG. 17 illustrates another embodiment of protective enclosure 1700 for a handheld electronic device 1702 that has an interactive flat-panel control such as, but limited to, a capacitance-sensing interactive flat panel control, a touch screen or other interactive control. Handheld electronic devices that have an interactive flat-panel control benefit from being enclosed in a rugged protective enclosure that is crush-resistant, watertight, and shock-resistant and that simultaneously allows the user to interact with a sensitive interactive flat-panel control. Handheld electronic devices that have interactive flat-panel control may include music players, MP3 players, audio player/recorders, video players, computers, personal digital assistants (PDAs), GPS receivers, cell phones, satellite phones, pagers, monitors, etc. For example, Apple Computer Ipod is a popular handheld interactive device that plays MP3 or otherwise digitally-encoded music/audio. The Apple Ipod has an interactive flat-panel control in which a portion of the front panel is a flat-panel display and portion of the front panel is an interactive flat-panel control, called a touch wheel in some versions of the Ipod and click wheel in other versions of the Ipod, that has capacitive touch/proximity sensors. One function of such an interactive flat-panel control, i.e. touch wheel, is that the control can emulate a rotary control knob by sensing circular motion of a user's finger using capacitive sensors. The click wheel has the same function with the additional feature of sensing proximity of a user's finger and emulating button presses by a user's finger at pre-determined areas.
[0114] In the embodiment of FIG. 17 , the shell lid 1706 and the shell base 1704 are made of polycarbonate or other engineered thermoplastics such as polyethylene, polypropylene, etc. that are crush-resistant and impact resistant. Shell base 1704 has a watertight seal 1718 , which may be an overmolded gasket, o-ring, liner or other seal that prevents water from entering the protective enclosure 1700 when the handheld interactive device 1702 is enclosed inside the protective enclosure 1700 . Shell base 1704 and shell lid 1706 may include watertight vents, electrical connectors, see-through areas or features as disclosed with respect to FIG. 1 .
[0115] In the embodiment of FIG. 17 , shell lid 1706 includes apertures over predetermined portions of the handheld interactive device 1702 , such as the areas directly over the display screen 1714 and the interactive flat-panel control 1712 , or other designated areas, as desired. A protective screen membrane 1710 , that is at least partially transparent, is permanently or removably fixed in a watertight manner to the underside of shell lid 1706 in the aperture that is over the display screen 1714 . The protective screen membrane 1710 may be recessed with respect to the upper surface of the shell lid 1706 which provides protective elevated rim that protects the display screen 1714 from breakage. Protective screen membrane 1710 may be PVC, silicone, polyethylene or other material that is watertight and rugged. In the case that display screen 1714 is a touch screen, the protective screen membrane 1710 should be smooth enough and thin enough that stylus strokes and other inputs are transmitted accurately to the touch screen as disclosed above with respect to FIG. 1 , FIG. 12 , and FIG. 13 . Alternatively, it may be desirable not to have an aperture in shell lid 1706 for a protective membrane 1710 . In another embodiment, the shell lid 1706 can be made of a transparent material so that a transparent window can be formed in the shell lid 1706 in place of the protective screen membrane 1710 . The transparent window is aligned with the display screen 1714 so that the user can view the display screen 1714 . In this case, a protective elevated rim that is aligned with the display screen 1714 is not required in the shell lid 1706 to protect the display screen 1714 from damage since there is no protective screen membrane 1710 . If the display screen 1714 is a touch screen, the material of the shell lid 1706 that is aligned with the display screen 1714 to provide a window can be made thinner to allow the touch screen to properly operate.
[0116] As also shown with respect to the embodiment of FIG. 17 , a protective control membrane 1708 is permanently or removably fixed in a watertight manner to the underside of shell lid 1706 in an aperture that is aligned with the interactive flat-panel control 1714 of the handheld device 1702 . The protective screen membrane 1710 is recessed with respect to the upper surface of the shell lid 1706 which provides protective elevated rim that protects the display screen 1714 from breakage and provides tactile feedback that guides a user's finger to the desired area, even in slippery conditions. Of course, the protective elevated rim may simply comprise the portion of the shell lid 1706 that is formed as a result of making an aperture in the shell lid 1706 and overmolding a protective touch-control membrane 1708 on an inside surface of the shell lid 1706 . In other words, the thickness of the shell lid 1706 creates a protective rim since the protective touch-control membrane 1708 is overmolded or otherwise attached to the back side of the shell lid 1706 . In that case, the rim is not elevated with respect to the surface of the shell lid 1706 , but rather, is elevated with respect to the membrane to form a protective rim.
[0117] Interactive flat-panel control 1712 has capacitive sensors, which are part of a proximity/touch detector circuit. When a grounded object, such as a person's finger, which has free air capacitance of several hundred picofarads, is brought close to the capacitive sensors, the total capacitance measured by the detector circuit increases because the capacitance of the object with free air capacitance adds to the capacitance of the sensors since the total capacitance of two capacitors in parallel is additive. Multiple sensors may also be arranged so that movement of an object with free air capacitance can be detected, for example, movement of a person's finger in a circular motion analogous to turning a mechanical control knob. Some examples of interactive flat-panel controlled PEDs include Ipod and Ipod Mini music and audio players from Apple Computer. In some PEDs, such as the Apple Ipod, capacitive sensors may be disposed below a front panel made from a dielectric such as polycarbonate, which has a dielectric constant in the range of 2.2-3.8. In the embodiment of FIG. 17 , the protective control membrane 1708 is made of thin polycarbonate that is slightly flexible or other engineered thermoplastics that provide the rugged watertight protection and at the same time permit the capacitive sensors of the interactive flat-panel control 1712 to function correctly. Likewise, a protective control membrane 1708 with a dielectric constant that is too high may retain an electric charge long enough to reduce the response rate of the sensor to motion of a user's finger from one capacitive sensor zone of the interactive flat-panel control 1712 to another. A protective control membrane 1708 that is conductive or has a dielectric constant that is too low may diminish the sensitivity of the capacitive sensor by combining in series the capacitance of the protective membrane and the dielectric front panel of the PED which results in a lowering of the overall capacitance.
[0118] Total capacitance between an object, such as a finger touching the protective control membrane 1708 , and interactive flat-panel control 1712 is a function of the thickness and the dielectric constant of the protective control membrane 1708 . The capacitance between the object, such as a finger, and the capacitive sensors of the interactive flat-panel control 1712 is proportional to the distance between the object and the sensors. The sensitivity of the capacitive sensors to the object may be diminished or completely eliminated if the protective control membrane 1708 is too thick. In the embodiment of FIG. 17 , the thickness of the protective control membrane is approximately 0.020 inches. The protective control membrane 1708 may be any thickness in the range of 0.003 inches to 0.020 inches that is adequate to provide a rugged watertight membrane through which capacitance can be correctly sensed by the interactive flat-panel control 1712 .
[0119] The upper surface of the protective control membrane 1708 has a velvet/matte texture with a texture depth of 0.0004 to 0.003 inches that reduces the surface area of the membrane that is in frictional contact with the user's finger and permits a user's finger to glide rapidly upon the surface of the membrane without catching or sticking as a result of the reduced friction. The hardness of the polycarbonate material, or other hard engineered thermoplastic, also reduces the friction.
[0120] Headphones or other accessories may be electrically connected to handheld device 1702 the through the protective enclosure 1700 by disposing the wire of the headphone or accessory in an insertable gasket 1716 which fits snugly into one end of the shell base 1704 .
[0121] FIG. 18 illustrates another embodiment of protective enclosure 1800 which is substantially the same as protective enclosure 1700 of FIG. 17 . However, protective enclosure 1800 has an alternative electrical pass-through for accessories. In the embodiment of FIG. 18 , shell base 1804 includes an adapter cable 1816 that has an adapter plug 1812 at one end which plugs into a jack of handheld device 1802 . At the other end of the adapter cable 1816 is an adapter jack 1814 that is molded into, or otherwise integrally made part of, shell base 1804 . An external accessory, such as a pair of headphones, may then be plugged into the adapter jack 1814 while the handheld device 1802 in enclosed in protective enclosure 1800 . Alternatively, a one-piece adapter that includes both a jack 1814 and a plug 1812 without a cable 1816 may be integrally disposed into shell base 1804 .
[0122] Shell lid 1806 is adapted to retain an O-ring 1808 that seals the protective enclosure 1800 when shell lid 1806 is latched tightly onto shell base 1804 so that water cannot enter protective enclosure 1800 .
[0123] FIG. 19 illustrates in the open position a crush-resistant, impact-resistant, watertight, protective enclosure 2000 for an electronic device such as a laptop computer. The protective enclosure 2000 may be manufactured in a manner similar to the enclosure of FIG. 13 comprising an impact/crush resistant material such as glass-fiber reinforced engineered thermoplastic, such as for example, glass reinforced polycarbonate. It may also be made of thermoplastic polycarbonate, thermoplastic polypropylene, thermoplastic acrylonitrile-butadiene-styrene, and thermoplastic compositions containing one or more thereof, or other engineered thermoplastics that provide a shock-resistant and impact resistant shell.
[0124] The inside of the enclosure is covered with a hook and loop liner 2002 . Shock absorbing corner bumpers 2004 have hook and loop type bases so that they may attach at any point on the liner inside the enclosure at the corners of the electronic device to secure electronic devices of various sizes and provides a shock absorbent suspension system for the devices. The shape of the bumpers may vary in size and in depth. They may also vary such that the laptop is raised a predetermined height for the bottom of the enclosure so that there may be access to the ports and external drives such as CD and DVD. These bumpers allow the enclosure to be adaptable to any size laptop computer by placing it inside the enclosure and securing it into position with the bumpers 2004 . Straps 2006 also secures the laptop into position. FIG. 20 illustrates a laptop 2008 secured in position as described above. An opening for a door or docking position 2010 may be provided that allows the case to be prewired for power or other USB connections. The watertight access ports may include holes that have a moveable watertight plug, or any type of watertight button or lever.
[0125] The liner 2002 may also have some cushioning that cushions the laptop and protects it against breakage if the enclosure and laptop are dropped or otherwise subjected to shock. Normally, however, most of the cushioning is provided by the corner bumpers and the liner is not cushioned. In accordance with the embodiment of FIG. 19 , the liner 2002 has a thickness of approximately 0.25.
[0126] This enclosure is also adaptable to protect PC tablets of the type illustrated in FIG. 13A . The hook and loop liner may be adjacent to the touch screen but does not exert mechanical pressure on the touch screen so that mechanical inputs such as style stokes are sensed only when intended. The engineered thermoplastics may be reinforced with glass fibers, carbon fibers, metal fibers, polyamide fibers, and mixtures thereof. Referring to FIG. 21 the enclosure 2000 may have an elevated protective rim 2012 substantially surrounding a perimeter of the enclosure. This rim may be further reinforced with stiffeners made of steel or other hard material that are integrally embedded into the enclosure so that the stiffeners provide additional strength and protection to the enclosed devices, as shown in FIG. 13B . An adjustable heavy-duty handle 2016 may be attached to or integrally designed into protective enclosure 2000 to allow easy and reliable transportation.
[0127] FIG. 22 illustrates the top of the enclosure wherein heavy-duty corner bumpers, such as bumper 2016 , provide additional protection against mechanical shock and are securely attached to the corners of the base. The ribs 2012 also substantially surround a perimeter of the base of the enclosure.
[0128] FIG. 23 illustrates a front view of the protective enclosure 2000 . An addition protective rib 2018 is provided along the front of the case and extends around the case on the ends, as shown in FIG. 24 .
[0129] FIG. 25 illustrates the back of the protective enclosure wherein an opening 2010 is provided in the protective enclosure 2000 which is sealed with a rubber plug 2020 . The plug 2020 of the USB hub is shown in more detail in FIG. 26 . The USB cable hub allows the protective enclosure 2000 to be wired for both power as well as USB connections. In addition, provisions may be made to provide ventilation for the enclosure through opening 2010 .
[0130] FIG. 26 illustrates the USB hub 2021 . The hub has mounting apertures such as 2022 that are disposed to receive fasteners to mount the hub inside of the protective enclosure 2000 . A USB connecter 2024 , that is disposed to connect to a USB slot in a computer laptop or PC tablet computer, is connected by a cable 2026 to the hub 2020 .
[0131] FIG. 27 illustrates the integrated USB hub 2021 mounted in the enclosure 2000 . The cable 2026 and USB connector 2024 allow a laptop computer or other computer to be connected to the USB hub 2021 . The corner bumpers 2004 are disposed to be removably attached to the enclosure lining 2002 so that the computer may be moved to a new location or the inside of the protective enclosure 2000 to facilitate the making of a connection between a laptop computer and the hub 2020 . The hook and loop liner 2005 , that is attached to the base of the shock absorbing corner bumpers 2004 , extends beyond the base dimensions by a predetermined amount to increase the adhesion between the bumpers 2004 and liner 2002 of the enclosure 2000 .
[0132] FIG. 28 illustrates how the USB assembly comprising the hub 2021 , cable 2026 , and connector 2026 may be mounted in an enclosure for a PC tablet protective enclosure such as 1400 shown in FIG. 14 .
[0133] The foregoing description of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and other modifications and variations may be possible in light of the above teachings. The embodiment was chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and various modifications as are suited to the particular use contemplated. It is intended that the appended claims be construed to include other alternative embodiments of the invention except insofar as limited by the prior art. | A protective cover for an electronic devices includes a protective shell base having an inner surface, an outer surface, and side members. The protective cover also includes a cushioning member configured for cushioning the electronic device when the electronic device is disposed in the protective shell base. The protective cover also includes a first opening configured to align with and expose at least a portion of a capacitance-sensing interactive touch screen display when the electronic device is disposed in the protective shell base. The protective cover also includes a second opening configured to align with a camera feature of the electronic device when the electronic device is disposed in the protective shell base. The protective cover further includes an access port positioned to be proximate an electrical interface of the electronic device when the electronic device is disposed in the protective shell base. | 8 |
RIGHTS OF THE GOVERNMENT
The invention described herein may be manufactured and used by or for the Government of the United States for all governmental purposes without the payment of any royalty.
FIELD OF THE INVENTION
The invention is generally related to computers and computer software. More specifically, the invention is generally related to a manner of edge detection in image processing.
BACKGROUND OF THE INVENTION
Traditional edge detection methods have generally required a high enough signal to noise ratio and fine enough image clarity that the transition from one region to another does not significantly exceed a single pixel in width. Even edge detection methods that have been adapted to noisy images still appear to carry the assumption that the noise is superimposed on top of an image with edges that do not exceed a single pixel in width.
In essence, edge detection has traditionally been a form of high-pass filtering, although in noisy images it performs better when implemented as a band-pass filter process. Since speckle noise has a definite high frequency component, the best results will naturally come from a process that excludes as much noise energy from the detection process as possible. In certain images, such as highly magnified images, low light images, or pictures taken of a moving object or where the camera is moved, the displayed resolution creates a non-negligible spatial auto-correlation among the pixel amplitudes. Thus, edges become border regions with non-zero width.
Images that have blur or noise conventionally cannot receive the benefits of edge detection. For example, digital photography effects such as embossing or conversion to a line drawing are not readily available. Certain artificial intelligence applications rely upon interpreting a scene. In some application, these limitations are partially offset by having knowledge of the expected shape and edge thickness of objects within a digital image so that a tailor-made template may be used for detection.
Consequently, a significant need exists for a way to tune the spectral response of edge detection to accommodate only the bandwidth of a natural edge in a particular image, and reject as much of the high frequency noise energy as possible, yet not require beforehand knowledge of the characteristics of the image clarity.
SUMMARY OF THE INVENTION
The invention addresses these and other problems associated with the prior art by providing an apparatus, program product and method in which “Wilson” horizontal and vertical edge detection kernels are formed of various sizes, each size sensitive to detecting edge widths of various sizes. Repeating convolution of a digital image with various sizes of Wilson kernels achieves edge detection even when the size of the edge is not known in advance.
In one aspect of the invention, an image is subjected to a series of edge detection processes using kernels tailored to border regions of increasing width, until the natural edge width is found. In blurred images, such a process yields improving results with successive iterations until the natural edge width for that particular image is reached. Further increasing the width of the kernel does not yield significant improvement, but rather begins to cause a loss of features, so the process is then halted. There are at least two advantages to this approach. First, since the method is noise tolerant, edges may be found in images otherwise too noisy or coarse for traditional approaches. Second, a measure of the natural edge width quantifies the blur in the image and acts as a metric for clarity.
These and other advantages and features, which characterize the invention, are set forth in the claims annexed hereto and forming a further part hereof. However, for a better understanding of the invention, and of the advantages and objectives attained through its use, reference should be made to the Drawings, and to the accompanying descriptive matter, in which there is described exemplary embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a block diagram of an edge detection processor within an image-processing environment.
FIG. 2 is an illustrative computer system for performing edge detection processing in the image-processing environment of FIG. 1 .
FIG. 3 is a flowchart of a sequence of operations performed by an edge detection routine to detect an edge of arbitrary width in the presence of noise in a digital image.
FIG. 4 is a flowchart of a generate Wilson kernels routine referenced in the edge detection routine of FIG. 3 .
FIG. 5 is a flowchart of a clean-peak adaptive threshold routine referenced in the edge detection routine of FIG. 3 .
FIG. 6 is a flowchart of a median thresholding routine referenced in the edge detection routine of FIG. 3 .
FIG. 7 is a flowchart of an isolation cleaning routine referenced in the edge detection routine of FIG. 3 .
FIG. 8 is a flowchart of a sequence of operations, or routine, for self-optimizing edge detection, which references the edge detection routine of FIG. 3 .
FIG. 9 is a flowchart of a calculate self-optimization metric routine referenced in the self-optimizing edge detection routine of FIG. 8 .
FIG. 10 is an illustrative example of results from the self-optimization metric routine of FIG. 9 .
FIG. 11 is a digital image including coarse resolution, noise and blur.
FIGS. 11A-11I are illustrative output results from edge detection using Wilson kernels size N=0 to 8 respectively.
DETAILED DESCRIPTION
Detection of multi-pixel edge regions in an image is achieved by an adaptive approach, wherein edge detection kernels are selected to accommodate the various pixel widths of the edge. In addition, an edge detection operation is performed when the edge detection kernels of various sizes have been used on the image. The edge detection operation may include multiplying the results achieved by each kernel for increased noise reduction or comparing the results from each kernel to determine the optimum kernel size for the natural edge width.
Turning to the drawings, wherein like numbers represent similar items throughout the several figures, FIG. 1 illustrates an edge detection processor 10 consistent with aspects of the present invention as part of an image processing system 12 . An image acquisition device 14 , such as a digital camera, prepares a digital image that is made available to the edge detection processor 10 as a stored image 16 . The processor 10 may be incorporated as part of the image acquisition device 14 or be a separate device. The edge detection processor 10 processes the stored image 16 in a memory 18 . The edge detection result is provided to post-edge detection processing 20 and then presented on a display 22 .
FIG. 2 illustrates in another way an exemplary hardware and software environment for an apparatus 58 consistent with the invention. For the purposes of the invention, apparatus 58 may represent practically any type of computer, computer system, or other programmable electronic device, including a computer (e.g., similar to computers 12 - 16 of FIG. 1 ), a server computer, a portable computer, a handheld computer, an embedded controller, etc. Apparatus 58 may be coupled in a network as shown in FIG. 1, or may be a stand-alone device in the alternative. Apparatus 58 will hereinafter also be referred to as a “computer”, although it should be appreciated that the term “apparatus” may also include other suitable programmable electronic devices consistent with the invention.
Computer 58 typically includes at least one processor 60 , depicted as a CPU, coupled to a system memory 62 . A system bus 64 couples various system components, including system memory 62 , to CPU 60 . System bus 64 may be any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of architectures. Processor 62 may represent one or more processors (e.g., microprocessors), and memory 62 may represent read-only memory (ROM) 64 and random access memory (RAM) 66 comprising the main storage of computer 58 , as well as any supplemental levels of memory, for example, cache memories, non-volatile, or backup memories (e.g., programmable or flash memories), read-only memories, etc. A basic input/output system (BIOS) 68 , containing the basic routines that help to transfer information between elements within computer 58 , such as during start-up, is stored in ROM 64 . In addition, memory 62 may be considered to include memory storage physically located elsewhere in computer 58 , (e.g., any cache memory in a processor 60 ), as well as any storage capacity used as a virtual memory, for example, as stored on a mass storage device or on another remote computer. Computer 58 has mass storage devices including a (typically fixed) magnetic hard disk 72 , a removable “floppy” or other magnetic disk 74 , and a CD-ROM, or other optical media 76 . The computer 58 may further include other types of mass storage such as direct access storage device (DASD), tape drive, etc. A hard disk drive 78 for hard disk 72 is connected to the system bus 64 via a hard disk drive interface 80 . A floppy disk drive 82 for floppy disk 74 connects to the system bus 64 via a floppy disk drive interface 84 . A CD-ROM drive 86 for CD-ROM 76 connects to the system bus 64 via a CD-ROM interface 88 .
A number of program modules are stored on mass storage media and/or ROM 64 and/or RAM 66 of system memory 62 . Such program modules may include an operating system 90 , providing graphics and sound application program interfaces (API), one or more application programs 92 - 96 , other program modules, and program data.
In general, the routines executed to implement the embodiments of the invention, whether implemented as part of an operating system or a specific application, component, program, object, module, or sequence of instructions, will be referred to herein as “computer programs,” or simply “programs.” The computer programs typically comprise one or more instructions that are resident at various times in various memory and storage devices in the computer, and that, when read and executed by one or more processors in the computer, cause that computer to perform the steps necessary to execute steps or elements embodying the various aspects of the invention. Moreover, while the invention has and hereinafter will be described in the context of fully functioning computers and computer systems, those skilled in the art will appreciate that the various embodiments of the invention are capable of being distributed as a program product in a variety of forms and that the invention applies equally, regardless of the particular type of signal bearing media used to actually carry out the distribution. Examples of signal bearing media include, but are not limited to, recordable type media such as volatile and non-volatile memory devices, floppy and other removable disks, hard disk drives, magnetic tape, optical disks (e.g., CD-ROMs, DVDs, etc.), among others, and transmission type media such as digital and analog communication links.
In addition, various programs described hereinafter may be identified based upon the application for which they are implemented in a specific embodiment of the invention. However, it should be appreciated that any particular program nomenclature that follows is used merely for convenience, and thus the invention should not be limited to use solely in any specific application identified and/or implied by such nomenclature.
A user may enter commands and information into the computer 58 through input devices such as a keyboard 98 and a pointing device 100 . Other input devices may include a microphone joystick, game controller, satellite dish, scanner, or the like. These and other input devices are often connected to processing unit 60 through a serial port interface 102 that is coupled to system bus 64 , but may be connected by other interfaces, such as a parallel port interface or a universal serial bus (USB). A monitor 104 or other type of display device is also connected to system bus 64 via an interface, such as a video adapter 106 .
Computer 58 may also include a modem 108 or other means for establishing communications over wide area network (WAN) 110 , such as communication network 12 . Modem 108 , which may be internal or external, is connected to system bus 64 via serial port interface 102 . A network interface 112 may also be provided for allowing computer 58 to communicate with a remote computer 114 via local area network (LAN) 116 (or such communication may be via wide area network 110 or other communications pat such as dial-up or other communications means). Computer 58 typically includes other peripheral output devices, such as printers and other standard devices.
Those skilled in the art will recognize that the exemplary environments illustrated in FIGS. 1 and 2 are not intended to limit the present invention. Indeed, those skilled in the art will recognize that other alternative hardware and/or software environments may be used without departing from the scope of the invention.
FIG. 3 illustrates a sequence of operations for edge detection, depicted as routine 130 . The size of an edge detection kernel is set to a minimum size N MIN (e.g., 0) without necessarily having a beforehand knowledge of the natural edge size of the digital image or the noise inherent in the image (block 132 ). A particularly useful type of edge detection kernel, which will be discussed in greater detail below with regard to FIG. 4, is illustrated in Tables 1-4. Specifically, two Wilson kernel classes are introduced, F HNT and F VNT , wherein ‘H’ denotes horizontal, ‘V’ denotes vertical, ‘N’ denotes the size, and ‘T’ refers to the taper of the coefficients of the kernel, which will be discussed below.
TABLE 1
Wilson Kernels F H01 , F V01
−1
1
−1
−1
−1
1
1
1
TABLE 2
Wilson Kernels F H11 , F V11
−1
0
0
0
1
−1
−1
−1
−1
−1
−1
−1
0
1
1
0
−1
−1
−1
0
−1
−1
0
1
1
0
0
0
0
0
−1
−1
0
1
1
0
1
1
1
0
−1
0
0
0
1
1
1
1
1
1
TABLE 3
Wilson Kernels F H21 , F V21
−1
0
0
0
0
0
0
1
−1
−1
−1
−1
−1
−1
−1
−1
−1
−1
0
0
0
0
1
1
0
−1
−1
−1
−1
−1
−1
0
−1
−1
−1
0
0
1
1
1
0
0
−1
−1
−1
−1
0
0
−1
−1
−1
0
0
1
1
1
0
0
0
0
0
0
0
0
−1
−1
−1
0
0
1
1
1
0
0
0
0
0
0
0
0
−1
−1
−1
0
0
1
1
1
0
0
1
1
1
1
0
0
−1
−1
0
0
0
0
1
1
0
1
1
1
1
1
1
0
−1
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
TABLE 4
Wilson Kernels F H31 , F V31
−1
0
0
0
0
0
0
0
0
0
1
−1
−1
−1
−1
−1
−1
−1
−1
−1
−1
−1
−1
−1
0
0
0
0
0
0
0
1
1
0
−1
−1
−1
−1
−1
−1
−1
−1
−1
0
−1
−1
−1
0
0
0
0
0
1
1
1
0
0
−1
−1
−1
−1
−1
−1
−1
0
0
−1
−1
−1
−1
0
0
0
1
1
1
1
0
0
0
−1
−1
−1
−1
−1
0
0
0
−1
−1
−1
−1
0
0
0
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
−1
−1
−1
−1
0
0
0
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
−1
−1
−1
−1
0
0
0
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
−1
−1
−1
−1
0
0
0
1
1
1
1
0
0
0
1
1
1
1
1
0
0
0
−1
−1
−1
0
0
0
0
0
1
1
1
0
0
1
1
1
1
1
1
1
0
0
−1
−1
0
0
0
0
0
0
0
1
1
0
1
1
1
1
1
1
1
1
1
0
−1
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
With reference to FIG. 4, the generate Wilson kernels routine 134 is depicted for calculating a kernel of any value N as set (block 136 ). A matrix is formed of size (3N+2)×(3N+2) (block 138 ). For a horizontal kernel, the middle N rows are given coefficients, or values, of zero (0). These middle N zero rows are flanked on both sides by row with the centermost N+2 coefficients having a nonzero value or opposite sign from the other, flanked by N zero values on each side (block 140 ). Each more outward row is a copy of its adjacent more inward row, except with two more centered nonzero values (block 142 ). The Wilson horizontal kernel F HNT is transposed to create the Wilson vertical kernel F VNT , as indicated at 144 in FIG. 4 .
Such a scheme allows for generation of kernels for any size N, including N=0. Moreover, both horizontal and vertical kernels detect diagonal edges. It should be appreciated that applications consistent with aspects of the invention may utilize other edge detection kernels. In addition, the kernels may be stored as a lookup table or in other available format without having to create a table.
Returning to FIG. 3, the Tables 1-4 illustrate a taper of equal magnitude coefficients for nonzero coefficients (e.g., −1, 1). Other taper functions may be advantageously selected (block 146 ). For example, for a row described as follows:
[− a (N+1) −a N . . . a 2 a 1 0 . . . 0 a 1 a 2 . . . a N a (N+1) ],
a taper profile includes a maximum at a 1 with a minimum at a (N+1) . Another taper profile has a maximum at a (N+1) tapering to a minimum at a 1 , which tends to provide a clean result. Yet another taper profile includes a maximum at a N/2 tapering in both directions. Examples of taper functions to provide these tapers include sinusoids and the square root of i/N, where I=1, 2, . . . (N+1).
Then each Wilson kernel is convolved with the digital image (blocks 148 , 150 ). The convolution results are optionally cleaned by clean-peak thresholding (blocks 152 , 154 ) and summed (block 156 ), discussed in greater detail below. Additional pixel cleaning may optionally include median thresholding (block 158 ) followed by isolation cleaning (block 160 ). In an illustrative embodiment, further optional pixel cleaning may be selected by repeating block 158 , then block 160 , then block 150 again.
The results are stored (block 162 ), advantageously allowing multiple passes of edge detection to be performed, suggested by the determination as to whether multi-kernel noise filtering (X=2) is selected (block 164 ). If so, then a determination is made as to whether the size of the kernel N is less than a predetermined maximum kernel size (block 166 ). If the maximum has not been reached, then the size N is incremented (block 168 ) and control returns to block 134 . If reached, then the results from use of each kernel are multiplied (block 170 ).
Multiplying the results from the various kernels takes advantage of the spectral properties of the kernels. Detection of infinitesimally thin edges is essentially a high pass filtering operation, which unfortunately includes much of the noise. Tailoring the kernels to find border regions with finite thickness rejects the high frequency components of the image, reducing the noise power and improving the Signal to Noise Ratio (SNR). As can be expected from basic Fourier Transform theory, as the kernel becomes wider, the bandwidth used in the detection process becomes narrower. This does reach a practical limit, though, as kernels must be small enough relative to image dimensions to capture detail. Since there is some overlap between the pass bands of each of the different kernels, it is possible to apply several operations using different widths (N), to take the absolute value of each convolution, and to then multiply the products together. The result is a more highly filtered set of detected edges with reduced noise.
If multi-kernel noise filtering was not selected in block 164 (X=1) or after multiplying the results in block 170 , then optional isolation cleaning is performed (block 172 ). Then a determination is made as to whether a binary (yes/no) decision output is desired (Z=1) (block 174 ), and if so, surviving pixels are set to 1 (block 176 ), else surviving pixels are set to confidence values (block 178 ). The confidence value refers to normalizing against the largest value in the result.
The various types of pixel cleaning operations referenced in FIG. 3 are depicted in greater detail in FIGS. 5-7. With reference to FIG. 5, the clean-peak thresholding routine 152 begins by calculating confidence values for each of the pixels (block 180 ). Direction of clean is selected, horizontal or vertical (block 182 ). If vertical is selected (block 184 ), then the result is transposed (block 186 ).
Application of a kernel to a bitmap image is described hereafter as being performed as a raster scan. In the illustrative method, the Wilson kernel is applied in the manner of a raster scan as used in computer and video graphic displays. In particular, displaying or recording a video image in computer monitors and TV's is line by line, based on the way in which a cathode ray tube electron gun is directed. Electrons are beamed (scanned) onto the phosphor coating on the screen a line at a time from left to right starting at the top-left corner. At the end of the line, the beam is turned off and moved back to the left and down one line, which is known as the horizontal retrace (fly back). When the bottom-right corner is reached, a vertical retrace (fly back) returns the gun to the top-left corner. In a TV signal, this is known as the vertical blanking interval. It will be appreciated by those skilled in the art having the benefit of the present disclosure that a kernel may be applied in various manners since the order in which pixels are tested is not critical to the result.
After horizontal is selected in block 184 or after being transposed in block 186 , then each pixel is tested. Specifically, a determination is made as to whether any pixels remain to be tested (block 188 ). If so, then the next raster position in the image is selected (block 190 ). A subset of N successive pixels at the current pixel position is selected (block 192 ). Consequently, N should be greater than or equal to 2. The median of the subset is determined, including pixels having a value of zero (0) (block 194 ). The pixel under test is flagged for later discarding if below the median for the subset (block 196 ). Then control returns to block 188 for testing for additional pixels, and if none, then flagged pixels are discarded by setting each to zero (0) (block 198 ).
Then, if the processing was for results from a vertical kernel (block 200 ), then the cleaned result is transposed (block 202 ). Routine 152 is complete if not vertical in block 200 or after being transposed in block 202 .
FIG. 6 illustrates the median thresholding routine 158 that includes ignoring pixels having a value of zero (0) (block 204 ). The confidence value for each pixel is calculated (block 206 ). The median for non-zero confidence values is found (block 208 ) and all nonzero pixels below the median are discarded by setting to zero (0) (block 210 ).
FIG. 7 depicts the isolation cleaning routine 160 that begins by calculating confidence values (block 220 ). Then, each pixel is tested for being an isolated pixel for cleaning. Specifically, a determination is made as to whether additional pixels remain to be tested (block 222 ), and if so, the next raster position is tested (block 224 ). The confidence values for all surrounding pixels are summed (block 226 ). If the sum is less than 0.5 (block 228 ), then the pixel under test is set to zero (0) as being an isolated pixel (block 230 ). If not under 0.5 in block 228 , then control returns to block 222 until all pixels have been tested and the routine returns.
FIG. 8 illustrates an advantage of the ability to scale the edge detection kernels to the natural edge of a digital image. Specifically, a self-optimizing edge detection routine 240 iteratively locates an optimum kernel for a blurred image having noise. The routine 240 does not require a beforehand knowledge of the clarity of the image or the type of edges contained therein in order to perform edge detection. First, the size of the kernel is set to N=1 (thus, a 5×5 kernel) (block 242 ). The options for utilizing the edge detection routine 130 are set to X=1, Y=1, Z=1 (block 244 ). Specifically, multiplying results of edge detection operations is turned off, clean-peak thresholding is selected, and binary output is selected. Then, edge detection routine 130 is run and the results for this pass is stored (block 246 ).
If the kernel size N is greater than 2 (block 248 ), then self-optimization metrics are calculated (block 250 ). If N is not greater than 2 or after calculating metrics, then N is incremented (block 252 ). Then, if N is not greater than a predetermined maximum N (block 254 ), then control returns to block 130 to perform the next pass. If the maximum allowable size for the kernel has been reached in bock 254 , then a natural edge width N OPTIMAL is determined by locating a peak composite metric (block 256 ) and the corresponding pass for this kernel size is output (block 258 ).
With reference to FIG. 9, the calculate self-optimization metric routine 250 referenced in FIG. 8 is depicted wherein the greatest change in pixels deemed to be an edge is found. In particular, first edge pixels are counted that are both in the Result(N) and the previous Result(N−1) and this count is the referred to as “Same” (block 264 ). The edge pixels are counted that were not in the previous Result (N−1) but are in the current Result(N) and referred to as “New” (block 266 ). Also, edge pixels were in the previous Result(N−1) but are not in the current Result(N) are counted and referred to as “Lost” (block 268 ). A first derivative of “Same” is estimated: Same′(N−1)=Same(N)-Same(N−1) (block 270 ). A first derivative of “New” is estimated: New′(N−1)=New(N)-New(N−1) (block 272 ). Also, a first derivative of “Lost” is estimated: Lost′(N−1)=Lost(N)-Lost(N−1) (block 274 ). The composite metric for Result(N−1) is then Same′(N−1)-New′(N)-Lost′(N) (block 276 ).
In the illustrative example, the composite metric is shown in FIG. 10, wherein the kernel of size N=6 is optimum. With reference to FIG. 11, a photograph of a grid shadow was intentionally created with significant blur in order to simulate an image collected with resolution exceeding the practical limit. Blur is the result of representing an image at a higher resolution than the true level of detail supported by the collection process and equipment. This photograph of FIG. 11 underwent self-optimizing edge detection routine 240 , resulting in the various Results shown in FIGS. 11A-11I. The optimal size 6 thus corresponds to the output image depicted in FIG. 11 F.
In use, a digital image undergoes successive convolutions with increasing sizes of Wilson vertical and horizontal edge detecting kernels with optional pixel cleaning processes to reduce noise in the output. The spatial bandwidth of successive passes provides an opportunity to reduce noise by multiplying the results of multiple passes. Alternatively, the ability of to find the natural edge of an over magnified or blurred image is supported by a self-optimizing edge detection routine that increases the size of the kernels used until the optimum is found.
By virtue of the foregoing, there is thus provided self-optimizing general edge detection that performs well in both noisy and blurred images and is suitable for use in imagery where conventional techniques begin to fail. The technique recognizes that edges may actually be transition regions of nontrivial finite width, and so it is able to find edges that span several pixels. Since kernels are generated according to a well-defined algorithm, the kernels are created for specified edge width under test, giving the technique scale independence. Combining kernels of differing sizes reduces vulnerability of the process to noise, giving the process improved noise tolerance.
While the present invention has been illustrated by the description of embodiments thereof, and while the embodiments have been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is, therefore, not limited to the specific details, representative apparatus and method, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the general inventive concept. | An apparatus, program product and method detect region boundaries, or edge, of an arbitrary number of pixels in width in a digital image that has coarse resolution, high noise levels and/or significant blur. A self-optimizing kernel generator detects edges of arbitrary thickness. In addition, combining results of multi-resolution edge detection provides significant noise tolerance, such as a 10 dB improvement over conventional techniques. Moreover, the edge detection preserves the precise location of a blurred edge and quantifies image clarity. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to insulating structures that are adapted to be inserted in a standard window opening on the interior of a room in which the window opening is situated so as to prevent thermal exchange between the internal environment of the room and the external environment. Thus, thermal exchange is minimized both during cold months, when it is desirable to prevent heat loss from the room, and in the summer, when it is desirable to maintain the room at an inside temperature that is cooler than the outside temperature. The present invention may be employed in conjunction with many existing window structures without inerfering with operation of those structures and which may be readily moved between an operative position in the window opening and a stored position away from the window opening.
In the last few years there has been an inceasing interest in energy conservation, particularly in the area of home heating and cooling. Studies resulting from this increased interest indicate that, for a typical home, a majority of unwanted energy transfer occurs through the windows and their associated window openings. Such losses result both from air leakage around the window and from the relatively poor insulating qualities of the thin layer of glass material used in the window structure. Accordingly, by insulating of a window opening, a large portion of these thermal losses may be eliminated, thus producing substantial energy savings for the home owner.
The value of insulating a window opening has been recognized for some time, although prior art attempts at solving this problem have taken different approaches than that contemplated by the present invention. One example of the prior art is the use of thermo-pane windows where an inner and outer panes of glass are separated by a vacuum. Other attempts have included the development of storm windows which comprise several spaced-apart layers of glass having a dead air space therebetween. Honeycomb blinds having side seals have also been utilized to create isolated air pockets that themally insulate the window opening.
Despite the relative successes of these approaches, there remains a need for a simple yet effective insulating closure for a window opening which closure may be mounted in the room interiorly of the standard window glass. There is a further need for such an insulating cover that is relatively inexpensive to manufacture, pleasing in appearance and which does not require special manufacturing machines. The present invention is directed towards satisfying these remaining needs.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a new and useful insulating insert that may be inserted into a window opening so as to decrease unwanted thermal transfer through the window opening.
Another object of the present invention is to provide an insulating closure for windows that may be mounted on the interior of a room between the window glass and the room which window closure is relatively inexpensive in manufacture and which is easy to install and operate.
Yet another object of the present invention is to provide a window closure that is easily moveable from an operative position wherein it is inserted into a window opening on the inside of the window glass and to a stored position away from the glass while presenting a pleasing, decorative appearance when it is in the both positions.
In order to accomplish these objectives, the present invention is directed to a window insulator assembly that is adapted to be inserted in a window opening on the interior side of a room. This assembly preferably includes a pair of flat panels formed of an insulating material that are hinged together along facing edges so that they may be placed in a planar position with respect to one another and also pivoted into a folded position. When the panels are in a planar position, they are configured to fit snuggly within the window opening, and edge seals extend around the perimeter of the panels as well as between the hinged adjacent edges. One of the panels is hinged, at its top, to the top sill of the window frame so that the panel may pivot outwardly from the window opening. A lower edge of the top panel has a latch member that will engage a latch mechanism secured to the ceiling of the room. In use, the window insulator assembly may be pivoted away from the window opening in which it nests so that the top panel catch becomes latched by the latch mechanism on the ceiling. A cord assembly is provided to then fold the bottom panel up against the top panel so as to provide minimum storage against the ceiling. When it is desired to re-insert the window insulator into the window opening, the bottom panel is released from the folded position and is bent back so that its upper edge attacks a release lever on the latching mechanism, thereby releasing the panel catch. The whole assembly may then be pivoted downwardly and to be snuggly fit into the window opening in such a manner that the edge seals prevent drafts around its perimeter.
Preferably, each of the panel sections is provided with a rigidifying channel molding extending around the perimeter and the interiorly facing surface of each panel section is adapted to receive a decorative covering so as to present a pleasing appearance. The panel sections may be formed of styrofoam or other insulating material and the window frame may include side ribs and a bottom rib which carry compressible side and bottom seals so that the edge seals are accomplished by a compressive abutment of the panel sections against these ribs. Also, the cord latch may be of a type that permits adjustable operation of the cord so that the lower panel may be retained at any desired angle with respect to the upper panel at an orientation between the planar position and the folded position of the panels. A fastener may be provided on the lower panel so that it engages the catch on the upper panel to retain the panels in a planar position.
These and other objects of the present invention will become more readily appreciated and understood from a consideration of the following detailed description of the preferred embodiment when taken together with the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the window insulator assembly according to the preferred embodiment of the present invention shown in a planar position for insertion into a window opening;
FIG. 2 is a cross-sectional side view of the preferred embodiment of the present invention shown positioned in a window opening;
FIG. 3 is a cross-sectional view taken about lines 3--3 of FIG. 2; and
FIG. 4 is a cross-sectional view taken about lines 4--4 of FIG. 1 of the corner detail shown in conjunction with the window opening.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention relates to window coverings in the form of an insulator assembly that is adapted to be inserted into a window opening in order to prevent thermal transmission therethrough. Thus, the present invention is very useful in preventing unwanted heat entry when it is desired to keep the room cooler than the external environment and also to prevent unwanted heat loss when it is desired to keep the room at a temperature greater than the external environment. This invention is further directed to providing a thermal insulator in an inexpensive manner yet in a way that is aesthetically pleasing.
As can be seen in FIGS. 1-4, window assembly 10 is shown mounted in a window opening 12 that is formed in a wall 14 of a building or other structure. A ceiling 16 extends perpendicularly to wall 14 above window opening 12. Window opening 12 mounts a standard window assembly 18 generally towards the exterior of wall 14. On the interior of wall 14, window opening 12 is surrounded by a window frame including a lower sill 22, a pair of side jambs 24, and an upper sill 26.
Window insulator assembly 10, in the preferred embodiment, is formed of first and second flat panels such as upper panel 28 and lower panel 30 which may be placed in a planar relationship to one another, as is shown in FIG. 1, and inserted into window opening 12. Panels 28 and 30 are sized for close-fitting insertion to opening 12 and thus are configured in the general shape of opening 12. In the figures, this configuration is described with respect to a standard rectangular frame window opening, although the present invention could be employed with other shapes of window openings.
Panel 28 has an upper edge 32 that is pivotally attached by hinges 34 to the lower surface of upper sill 26. These hinges allow panel 28 to be pivoted into the interior of the room so that a lower edge 36 of upper panel 28 may be moved out of opening 12 to a position adjacent ceiling 16, as is shown in phantom in FIG. 2. An upper edge 38 of panel 30 is pivotally attached to lower edge 36 by means of hinges 40 so that panel 30 may be folded back alongside panel 28 with a lower edge 42 of panel 30 is alongside edge 32. As is shown in FIGS. 1 and 2, panels 28 and 30 have a common width and thickness, but lower panel 30 is preferably sized to have a longer length than upper panel 28 so that, when panel 30 is folded back alongside panel 28, edge 42 extends into opening 12 past edge 32 of panel 28. In this manner, panel 30 masks hinges 34 so as to present a more pleasing appearance.
It should thus be appreciated that window assembly 10 may be moved between an operative position wherein panels 28 and 30 are substantially planar and inserted in opening 12, as is shown in FIG. 2, to a stored position wherein panel 28 is pivoted toward ceiling 16 and panel 30 is folded back alongside panel 28. To retain panel 28 in the stored position, a latch mechanism interconnects panel 28, along its lower edge 36, to a complimentary latch mechanism positioned on ceiling 16. As is shown in FIGS. 1 and 2, panel 28 includes a catch 44 located at its interior surface and centered along edge 36. Ceiling 16 is provided with a latch 46 that releaseably engages catch 44. Latch 36 includes a release lever 48 that, when operated, releases catch 44 after it has been engaged by latch mechanism 46. Latch 46 may typically be of a type commonly used with storm doors and the like, wherein a release lever 48 is depressed to release a catch received by latch 46. A fastener 50 is secured to lower panel 30 along a central portion of its upper edge 38 with fastener 50 also being constructed to engage catch 44 so as to releaseably retain panels 28 and 30 in a planar orientation with respect to one another. A handle 52 is also mounted on the interior surface of panel 30 along lower edge 42 to facilitate insertion and removal of window insulator assembly 10 into and out of opening 12.
Once upper panel 28 is received by latch 46, it is necessary that lower panel 30 be folded alongside panel 28 so as to prevent lower panel 30 from being an unwanted obstacle depending from ceiling 16, as is shown in FIG. 2. As noted above, panel 30 is pivotal on edge 38 and about adjacent edge 36 so that it may be placed in a folded condition. To facilitate this, a draw cord mechanism is provided. Specifically, a mounting member 54 is attached to the outer surface of lower panel 30, adjacent edge 42. A retaining pulley 56 is mounted at an upper corner of opening 12, with pulley 56 being attached, by an convenient bracket, to upper sill 26. Retaining pulley 56 is of a type commonly used with venetian blinds that permits selective adjustment and gripping of a cord threaded therethrough. To this end, a cord 66 is fastened, at one end, to mounting member 54 and is threaded through pulley 56 so that cord 66 has a free end 68 that hangs alongside one of side jambs 24 in opening 12. By pulling on free end 68 of cord 66, edge 42 of panel 30 is drawn toward edge 32 of panel 28 so that panels 28 and 30 are placed in a folded configuration, as is shown in phantom in FIG. 2.
In order to facilitate a complete seal around and between panels 28 and 30, edge seals, upper and lower seals, and an intermediate seal are provided. Specifically, as is shown in FIG. 1, an upper seal 70, in the form of a strip of compressible material, extends across the entire width of panel 28 on edge 32, and an intermediate seal 72 is mounted on one of facing edges 36 and 38 completely across the common width of panels 28 and 30. When panels 28 and 30 are placed in a planar position, edges 36 and 38 compress seal 72 prevent air from passing between these adjacent edges of panels 28 and 30. Likewise, when panel 28 is placed in a nested position within opening 12, seal 70 is pivoted against top sill 26 to prevent air from passing across the top of panel 28. To complete the sealing of the perimter of panels 28 and 30, side ribs 74 are attached to side jambs 24 and side seals 76, in the form of elongated, compressible strips extend along side edges of each of panels 28 and 30, and include end portions 77 that overlap respective edges 32, 36, 38 and 42. A bottom rib 78 extends across lower seal 22 in a common plane with side ribs 74. Rib 78 has an outwardly facing surface that receives an elongated, compressible sealing strip 80. When panels 28 and 30 are in a planar position and are inserted into close-fitting engagement with opening 12, the side seals 76 compress against ribs 74 and a lower edge portion of lower panel 30 abuts and compresses sealing strip 80 so that, in conjunction with upper strip 70, completely seals the perimeter of this panel assembly. Instead of placing seals 76 on panels 28 and 30, seals 76 could be directly mounted to ribs 74 in a manner similar to that described for seal 80.
Panels 28 and 30 may be formed of any convenient material, but, in the preferred form of this invention, a light-weight, styrofoam material is selected. The front and back surfaces of each of panels 28 and 30 are provided with a stiffening or backing material 82, shown with respect to panel 30 in FIG. 4, which may be in the form of a light-weight cardboard, that helps strengthen styrofoam panels 28 and 30 from accidental breakage yet which maintains their lightweight construction. To further strengthen panels 28 and 30, as is shown in FIGS. 1 and 4, each of panels 28 and 30 include a channel-shaped molding that extends completely around their respective perimeters. These moldings may be formed of a wood or plastic material, but it is preferred that each of molding pieces 84 be formed of a non-thermally conducting substance. Further, to enhance the appearance of panels 28 and 30 from the interior of the room in which window opening 12 if formed, a decorative material 86, such as a fabric, wall paper or the like, may be placed over desired backings 82. In the alternative, backings 82 could be painted in any desired manner so as to provide a more aesthetically pleasing appearance.
The operation of window insulator assembly 10 can now be more fully appreciated and understood. When it is desired to move insulating assembly 10 out of an insulating relationship with opening 12, fastener 50 is rotated so that it releases catch 44, and the user pulls handle 52 so as to remove panels 28 and 30 from opening 12. This movement pivots panel 28 about top sill 26 on hinges 34 so that edge 36 moves toward ceiling 16. Simultaneously, panel 30 is maintained in a vertical orientation, as is shown at A in FIG. 2, so that panels 28 and 30 pivot with respect to one another. This movement is continued until catch 44 engages latch 46 and is retained thereby. Handle 52 may then be released and the user may pull free end 68 of cord 66 so that edge 42 is drawn toward edge 32 and is retained in the folded position shown at B in FIG. 2, by manipulating retaining pulley 56 as is known in the art. When it is desired to release panels 28 and 30 from the folded or stored position, free end 68 is again manipulated to release cord 66 from retaining pulley 62 so that panel 30 is again moved generally perpendicular to a vertical position perpendicular to ceiling 16. In order to release panel 28, the user pulls handle 52 outwardly away from wall 14 so that edge 38 of panel 30 attacks release lever 48, as is shown in FIG. 2, so that, when lever 48 is moved a sufficient distance, latch 46 releases catch 44. Panels 28 and 30 are then pivoted with respect to one another while panel 28 is pivoted on hinges 34 so that the panels move into abutment with ribs 74 and 78. This compresses upper seal 70, intermediate seal 72, side seals 76 and bottom seal 80 so that a relatively air-tight structure is provided.
From the foregoing, it should be appreciated that latch 46 and retaining handle 48 must be positioned so that edge 38 may attack release lever 48. To this end, as is shown in FIG. 2, latch 46 is mounted on a block 88 that has an inclined surface 90 that is formed at an angle with respect to ceiling 16 which is approximately the same as the angle panel 28 makes with ceiling 16 when catch 44 is received by latch 46. To permit edge 38 to more conveniently attack release lever 48, a spacer block 92 may be mounted on release lever 48. Spacer block 92 has an inclined surface 94 that is generally parallel to ceiling 16 and is sized so that edge 38 will attack inclined surface 94 upon only a relatively small outward movement of panel 30 outwardly into the room. To further enhance this structure, upper edge 32 of panel 38 may be attached to upper sill 26 by means of a mounting member 96, such as a flat board, which extends across top sill 26 and is attached thereto. Hinges 34 and pulley 56 are then attached to mounting member 96. In this manner, window insulator assembly 10, with the exception of side ribs 74 and bottom rib 78 may be completely removed from opening 12 simply by removing mounting member 96.
Accordingly, the present invention has been described with some degree of particularity directed to the preferred embodiment of the present invention. It should be appreciated, though, that the present invention is defined by the following claims construed in light of the prior art so that modifications or changes may be made to the preferred embodiment of the present invention without departing from the inventive concepts contained herein. | A removable, insulated window covering in the form of two insulated, bifolding panels hinged together and mounted over a window are foldable from a position covering the window to a nested storage position above the window. Side and edge seals are provided, as well as folding and latching mechanisms, for moving the panels between the use and storage positions and for retaining the panels in those positions. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates to a magnetic recording medium which is suitable for the high-density magnetic recording and to a magnetic recording apparatus which uses this magnetic recording medium.
In the field of magnetic recording, there are the schemes of longitudinal recording and perpendicular recording, of which the former is generally adopted at present. The longitudinal recording is a scheme of magnetic recording in which a magnetic recording head is used to form record bits by magnetizing the magnetic recording medium in parallel to the medium surface and in such directions that N poles or S poles of adjacent bits face to each other. The perpendicular recording is a scheme of magnetic recording in which a magnetic recording head is used to form record bits by magnetizing the magnetic recording medium perpendicularly to the medium surface such that adjacent bits are magnetized in anti-parallel directions.
Both schemes are designed to read recorded information out of the recording medium based on the detection with the magnetic head of the magnetic flux straying from recorded bits. Therefore, the greater the quantity of stray magnetic flux, the higher is the detected output level of recorded information by the magnetic head. The quantity of stray magnetic flux from a bit is approximately proportional to the magnetic moment which forms the bit. Namely, for magnetization M which is the magnetic moment per unit volume of the medium and the volume V of a recorded bit, the stray magnetic flux φ from a bit is approximately proportional to MV.
This means that if the area of a recorded bit on the medium decreases as a result of the raising of recording density, the stray magnetic flux from the bit will decrease and the head output level will fall. On this account, in order to accomplish the high-density recording, it is necessary to enhance the sensitivity of reproduction head to the extent of compensating the reduced stray magnetic flux and ensure a sufficient magnitude of magnetization M of the medium.
SUMMARY OF THE INVENTION
The magnitude of magnetization of the magnetic recording medium varies depending on the temperature. Generally, ferromagnetic substance has a trend of directing the magnetic moment of ferromagnetic atoms to the same direction due to the exchange interaction between magnetic moments. The magnetic moment, except for the state of 0° K, is fluctuating by receiving thermal energy. The higher the temperature, the greater is the amplitude of fluctuating. Accordingly, as the temperature rises, the thermal fluctuation energy supersedes the energy that equalizes directs to the same direction of the magnetic moment based on the exchange interaction. The magnetization which is the value of the average magnetic moment per unit volume decreases gradually with the rise of temperature, causing the transition of the medium from ferromagnetic substance to non-magnetic substance at the Curie temperature.
Therefore, even though there is ensured a sufficient magnitude of magnetization of the medium at the room temperature, if the magnetization of medium decreases sharply due to the temperature rise of the magnetic recording apparatus within its operating temperature range, the stray magnetic flux from recorded bits will also decrease sharply, resulting in a reduced output of the reproduction head.
Accordingly, it is an object of the present invention to accomplish a high recording density and provide a magnetic recording medium and a magnetic recording apparatus which are capable of producing a sufficient reproduction output throughout the operating temperature range of the magnetic recording apparatus.
At the current laboratory development stage, there is reported the accomplishment of a magnetic recording medium of the type of longitudinal recording having an areal recording density of the order of 10 Gbit per square inch (The 7th MMM-Intermag Joint Conference, session ZA, San Francisco, U.S.A., January 1998). With the bit length to track width ratio being assumed to be 20 to 1 approximately that is adopted in general, the linear recording density is evaluated to be about 400 kFCI and the bit length to be about 60 nm.
In order for the longitudinal recording scheme to achieve a high medium S/N performance of recording and reproduction at a high linear recording density, it is necessary to minimize the length of transition region between recorded bits thereby to reduce the transition noise attributable to the zig-zag domain of the transition region of the medium.
The length of transition region of the medium is generally proportional to the product of the thickness t of the magnetic recording layer of the medium and the residual magnetization Br of the recording layer. Accordingly, the smaller the product Br·t of the residual magnetization and film thickness, the smaller is the noise and more improved is the medium S/N at a high linear recording density. However, a smaller product Br·t in excess causes the stray magnetic flux from recorded bits to decrease, resulting in a reduced reproduction head output. On this account, in order to prevent the deterioration of the medium S/N and head output at a high linear recording density, the product of the residual magnetization and film thickness needs to be set in the range: 30 Gauss·μm<Br·t<80 Gauss μm.
For a linear recording density as high as around 400 kFCI, the bit length becomes about 60 nm, and assuming that magnetic crystal grains of the recording film have an average size of 15 nm or more, the bit length is filled by four crystal grains at most. The fluctuation of zig-zag domain in the transition region attributable to the distribution of crystal grain sizes and the distribution of crystal grain orientation will increase, resulting in an increased medium noise which is derived from the transition noise. Therefore, it is necessary to increase the number of crystal grains in the bit length direction and reduce the average crystal grain size below 15 nm.
However, a magnetic crystal grain with a size smaller than or equal to 5 nm is too small in its volume, causing the thermal fluctuation energy of magnetic moment to supersede the magnetic anisotropic energy of magnetic crystal grain for directing its magnetic moment to the easy axis of magnetization, and it cannot have the magnetic moment orientation stabled in the direction of easy axis of magnetization, exhibiting the property of super-paramagnetism. On this account, the size d of magnetic crystal grains needs to be in the range: 5 nm<d<15 nm.
Next, it is necessary to make the stray magnetic flux from recorded bits less dependent on the temperature variation and let the magnetic head produce a large output signal even if the temperature varies. Specifically, the medium structure needs to be designed so that the temperature-dependent variation in the quantity of stray magnetic flux from recorded bits decreases at least in the operating temperature range of the magnetic recording apparatus. For the achievement of this requirement, the inventive magnetic recording medium adopts the ferromagnetic thin film structure having a small temperature-dependent variation of saturation magnetization at least in the temperature range smaller than or equal to 350° K.
The magnitude of saturation magnetization of the medium decreases as the temperature rises, as mentioned previously, and the magnetization vanishes at the Curie temperature. FIG. 1 is a brief graphical representation of the temperature-dependent variation of saturation magnetization. Generally, the temperature-dependent variation of saturation magnetization increases as the temperature approaches the Curie temperature. Accordingly, if the Curie temperature of the medium is close to the operating temperature range of the magnetic recording apparatus, the medium has its magnetization varied greatly in response to the temperature variation even within the operating temperature range. Therefore, the Curie temperature needs to be high enough outside the operating temperature range of the apparatus.
Magnetic alloy has its Curie temperature affected greatly by the combination and proportion of elements which compose the magnetic material and is also dependent on as to whether the material is in the order state or disorder state in the case of order alloy. Briefly, in case a non-magnetic element is added to Co, the Curie temperature in the alloy state is prone to be lower as compared with the Curie temperature of the simple Co element. This trend is more pronounced as the quantity of additive element increases. The reason for this phenomenon is the emergence of portions where the exchange interaction between Co atoms weakens due to the replacement of the Co element in the crystal orientation with the non-magnetic element.
The magnetic recording medium is a polycrystalline thin film formed of magnetic crystal grains having sizes of around 15 nm or less. The magnetic characteristics of the whole film are derived generally from the magnetic characteristics of each crystal grain. Provided that each magnetic crystal grain has a sufficiently high Curie temperature outside the operating temperature range of the magnetic recording apparatus and has a property of smaller variation of magnetization within the operating temperature range, the film of medium will have the same trend of general magnetic characteristics.
This property is attained by increasing the proportion of ferromagnetic element and reduce the additive element in each magnetic crystal grain. However, if the proportion of magnetic element in magnetic crystal grains is simply increased, the exchange interaction between crystal grains emerges, resulting in an increased noise at the reproduction of medium attributable to the zig-zag domain in the transition region of recorded bits. Therefore, it is necessary to design the medium structure so that the exchange interaction between crystal grains weakenes, i.e., non-magnetization for the grain boundary.
There is a conflict between the magnetic characteristics required of the crystal grain itself and the magnetic characteristics required of the grain boundary as mentioned above. A magnetic recording medium which meets these two conflicting characteristics can be accomplished based on the film forming process with higher sputtering energy as compared with the conventional sputtering process for a magnetic material of Co—Cr alloy, for example, and the subsequent annealing process so that the additive element in magnetic crystal grains diffuses and segregates to grain boundaries, as will be described in the following embodiment of invention.
Specifically, the present invention resides in a magnetic recording medium having a magnetic recording film formed on a substrate, wherein the magnetic recording film has an average magnitude of saturation magnetization Ms(T=5° K) at 5° K and average magnitude of saturation magnetization Ms (T=300° K) at 300° K which satisfy: Ms(T=300° K)/Ms(T=5° K)≧0.75.
With the size of a magnetic crystal grain of the magnetic recording film being defined in terms of the diameter of a circle having the same area as the magnetic crystal grain along the film surface, the average size d of magnetic crystal grains is preferably greater than 5 nm and smaller than 15 nm. Preferably, with respect to the minimum bit length L of recorded bits, the average size d of magnetic crystal grains satisfies: 12>L/d>4.
In the case of a magnetic recording medium of the type of longitudinal recording, the thickness t (μm) of the magnetic recording film and the average residual magnetization Br (Gauss) of the magnetic recording film at 300° K satisfy preferably: 30 Gauss·m<Br·t<80 Gauss·μm.
With the saturation magnetization Ms (T) being normalized by Ms(T=5° K) to be m(T)=Ms(T)/Ms(T=5° K) within the temperature range: 5° K≦T≦350° K and formulated approximately by a polynomial of absolute temperature T, the normalized saturation magnetization m(T) decreases virtually linearly in proportion to T 2 , and this linear relation, when expressed in terms of the gradient A of the slope and the intersection B of the slope with the m(T) axis as m(T)=−A·T 2 +B, satisfies: 0<A≦2.8×10 −6 (K −2 ). The relation m(T1)=0 is met at a temperature T1 of T1≧600° K. The normalized saturation magnetization m(T) has a temperature-dependent variation per 1° K of 0.002 at maximum within the temperature range: 5° K≦T≦350° K.
Magnetic recording apparatus are designed to operate at temperatures ranging from the lowest 0° C. (273° K) up to the highest 50° C. (323° K) in general, and the apparatus interior temperature will rise up to around 75° C. (348° K). Accordingly, if the constant A and T1 and the temperature-dependent variation of m(T) meet the above conditions, the variation of saturation magnetization within the temperature range from about 273° K to about 350° K can be as small as around 15%, and the variation of head output signal level attributable to the temperature-dependent variation of saturation magnetization is confined within the allowable range for the operation of apparatus.
The present invention also resides in a magnetic recording apparatus which includes a magnetic recording medium, a recording medium driver, a magnetic head, a head driver, and a recording/reproduction signal processing system, with the above-mentioned magnetic recording medium being used for the recording medium.
The inventive magnetic recording medium can be adapted to longitudinal recording in which the average magnetic moment of recorded bits on the medium is virtually parallel to the film surface, and also to perpendicular recording and oblique recording in which the magnetic moment of recorded bit is not parallel to the film surface.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a brief graphical representation of the temperature-dependent variation of saturation magnetization;
FIGS. 2A and 2B are brief cross-sectional views of examples of structure of magnetic recording media for longitudinal recording;
FIG. 3 is a graph showing the temperature-dependent variation of normalized saturation magnetization of a magnetic recording medium formed of Co—Cr alloy for longitudinal recording;
FIG. 4 is a graph showing the dependency on temperature T 2 of the normalized saturation magnetization;
FIG. 5A is a brief cross-sectional view of the inventive magnetic recording medium for perpendicular recording;
FIG. 5B is a brief cross-sectional view of the conventional magnetic recording medium for perpendicular recording;
FIG. 6 is a graph showing the dependency on temperature T 2 of the normalized saturation magnetization;
FIG. 7A is a brief plan view of the magnetic recording apparatus based on this invention; and
FIG. 7B is a brief cross-sectional view taken along the line A—A of FIG. 7 A.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of the present invention will be explained with reference to the drawings.
Embodiment 1
FIGS. 2A and 2B are brief cross-sectional views showing examples of the inventive and conventional magnetic recording media, respectively, for longitudinal recording. The inventive recording medium has a structure in which an growth-orientation control underlayer 12 and a lattice mismatch adjusting layer 15 are formed sequentially on a substrate 11 , with a magnetic recording film 13 and a protection film 14 being formed thereon. In contrast, the conventional recording medium has a structure in which a thin film 23 of cobalt alloy is formed as recording layer on the substrate 21 through an orientation control underlayer 22 of magnetic film, with a protection film 24 being formed thereon.
Next, the fabricating procedure of the magnetic recording medium of the inventive structure shown in FIG. 2A will be explained. A cleaned quartz substrate 11 for the 3.5-inch disk was placed on the sputtering device for film formation, the chamber was evacuated to a degree of vacuum of 1×10 −8 Torr or lower, the substrate 11 was heated to 300° C., and it was kept at the steady-state temperature for one hour. On the substrate 11 , a Cr film (thickness: 10 nm) for the orientation control underlayer 12 and a Cr—15 at % Ti film (thickness: 30 nm) for the lattice mismatch adjusting layer 15 were formed sequentially. These two underlayers were formed by the d.c. magnetron sputtering process at an Ar gas pressure of 3 mTorr and at a deposition rate of 2 nm/s.
After that, on the resulting multi-underlayer film, a magnetic film (thickness: 15 nm) 13 having an average composition of Co—15 at % Cr—10 at % Pt—3 at % Ta was formed by the ECR (Electron Cyclotron Resource) sputtering process which is higher in energy at film formation than the d.c. magnetron sputtering process. During the film forming process, the Ar gas pressure was kept at 0.5 mTorr and the d.c. voltage applied to the targets was adjusted so that the deposition rate is 0.3 nm/s.
Subsequently, with the vacuum state being retained, a heat treatment in vacuum was conducted. Specifically, the heating chamber was evacuated to a degree of vacuum of 5×10 −9 Torr, the substrate with the film formed thereon was heated to a steady-state temperature of 450° C., kept heated for one hour, and cooled down to the room temperature at 25° C./min. After that, a carbon protection film (thickness:15 nm) was formed on the outmost surface at the room temperature.
All targets except for the C target have a purity of 99.9%, and alloy targets were used to form the alloy thin film. The above-mentioned film composition of each layer was assessed in terms of the average composition of thin film determined based on the scheme of ICPS (Inductively Coupled Plasma Spectroscopy). This sample of medium will be called “sample A” hereinafter.
A magnetic recording medium for comparison having a cross-sectional structure shown in FIG. 2B was fabricated in the following manner. Shown is an example of fabrication of a medium having a magnetic film composition of Co—20 at % Cr—8 at % Pt. A cleaned NiP-plated Al alloy disk 21 for the magnetic disk was placed on the sputtering device for film formation, the chamber was evacuated to a degree of vacuum of 1×10 −8 Torr or lower, the substrate 21 was heated to 270° C., and it was kept at the steady-state temperature for one hour. On the substrate 21 , a Cr film (thickness: 50 nm) for the orientation control underlayer 22 , a Co—Cr—Pt magnetic film (thickness: 15 nm) 23 and a carbon protection film 24 were formed sequentially. These thin films were formed by the d.c. magnetron sputtering process at an Ar gas pressure of 3 mTorr.
All targets except for the C target have a purity of 99.9%, and alloy targets were used to form the magnetic film. This sample of medium will be called “sample B” hereinafter.
The fabricated medium samples underwent the assessment of recording/reproduction characteristics, and were thereafter cut into pieces and examined for the film structure and magnetic characteristics. The structure of medium thin film was examined based on the x-ray diffraction scheme. As a result of the θ-2θ x-ray diffraction measurement for sample B of the conventional structure, the (200) surface reflection of the Cr underlayer 22 and the (11.0) surface reflection of the hexagonal close packing structure of the Co—Cr—Pt magnetic film 23 were observed.
For sample A, the (200) surface reflection of the Cr—Ti underlayer 15 and the (110) surface reflection with an x-ray diffraction strength, which was {fraction (1/10)} of the (200) surface reflection, were observed. The major reflection of the magnetic film 13 was the (11.0) surface reflection, and a (10.1) surface reflection peak which is about {fraction (1/15)} in strength of the major reflection peak was observed. The measurement result suggests the growth of the magnetic film 13 in the (10.1) orientation based on that most crystal grains of the Cr—Ti underlayer 15 are in the (100) orientation, the magnetic film 13 of epitaxial growth on this underlayer is in the (11.0) orientation, and partial magnetic crystal grains form the Cr—Ti underlayer in the (110) orientation. The diffraction surface of the magnetic film was displayed in the manner of four-index display, with the third term being omitted. There was confirmed no clear x-ray diffraction peak from the Cr underlayer 12 .
For the examination of the detailed crystal structure of both samples, an electron microscope was used to observe the planar TEM image of the magnetic film. Sample B of the conventional structure has a broad distribution of crystal grain sizes with an average size of about 15 nm. In contrast, sample A has a crystal grain size distribution narrower by about 20% than that of sample B, with the average size being about 12 nm.
In regard to the cross-sectional structure of crystal grains, it was found that the Cr—Ti underlayer and magnetic film have a continuous crystal lattice and are created based on epitaxial growth. The size of a crystal grain is defined in terms of the diameter of a circle having the same area as the crystal grain along the film surface.
For the examination of the distribution of composition at the scale of crystal grain, the composition analysis was conducted at arbitrary measuring points of the magnetic film by use of an EDX (Energy Dispersive X-ray) spectroscope having a spatial resolution of 2 nm. The result of analysis for sample A reveals that the Cr element is as much as 30 at % or more at the grain boundary and has an average value of about 8 at % inside the crystal grain. The quantity of Cr inside the crystal grain is half the average composition of the film.
The analysis result for sample B reveals that the concentration of Cr element is as much as 23 at % at the grain boundary, which is merely greater by about 3 at % than the average composition. Although the observation inside the crystal grain indicates the reduction of Cr concentration by about 3 at % at the section near the grain boundary relative to the average composition due to the segregation of Cr at the grain boundary, the central section of crystal grain is virtually consistent with the average composition. Namely, sample B did not exhibit a clear composition segregation structure that causes the variation of composition of the entire crystal grain which was observed in sample A.
For samples A and B, magnetization curves were plotted at various temperatures ranging from 5° K to 350° K. FIG. 3 shows the temperature-dependent variation of saturation magnetization m normalized by the magnitude of saturation magnetization of each sample at T=5° K. Both samples exhibit the simple decrease of the normalized saturation magnetization with the rise of temperature. Sample B has a greater variation of m=0.65 at T=300° K as compared with m=0 at T=300° K of sample A. Both samples A and B have a product Br·t of the residual magnetization and film thickness of 55 Gauss·μm.
FIG. 4 is a graph which is derived from FIG. 3, with the normalized saturation magnetization m(T) being plotted along the horizontal axis of T 2 . Both samples exhibit the simple virtually-linear decrease of the normalized saturation magnetization(T) with T 2 and it can be expressed approximately as m(T)=−A·T 2 +B. For the measurement result of sample A, constants A and B of the approximate expression are evaluated by using the least square method as follows.
m ( T )=1.00−(1.11×10 −6 ) T 2 (1)
The slope intersects the T 2 axis at temperature T1=946° K.
The normalized saturation magnetization m(T) decreases simply with the temperature rise, i.e., increase of T 2 , as shown in FIG. 4, and m(T) has the largest temperature-dependent variation at around T=350° K in the temperature range 5° K≦T≦350° K. Sample A takes m(T=320° K)=0.896 and m(T=340° K)=0.871, and the variation of m(T) per 1° K is evaluated to be 0.0013 as follows.
Δ m=−[m ( T= 340° K)− m ( T= 320° K)]/[340° K−320° K]=0.0013 (2)
For sample B, the approximate expression m(T)=−A·T 2 +B has its constants determined as shown by (3) in the following, and the slope intersects the T 2 axis at temperature T1=500° K. It takes m(T=320° K)=0.59 and m(T=340° K)=0.538, and the variation of m(T) per 1° K is Δ m=0.003.
m ( T )=1.00−(4.01×10 −6 ) T 2 (3)
The magnetic recording media having the foregoing magnetic characteristics were used to build a magnetic recording apparatus. This magnetic recording apparatus has the known structure, as shown by a plan view in FIG. 7A and a cross-sectional view in FIG. 7B taken along the line A—A of FIG. 7 A. It includes a magnetic recording medium 91 , a medium driver 92 which turns the recording medium 91 , a magnetic head 93 which records and reproduces signals by moving across the turning recording medium 91 , a head driver 94 which moves the magnetic head 93 across the recording medium 91 , and a recording/reproduction signal processing system 95 which supplies a signal to be recorded to the magnetic head and processes the reproduced signal from the magnetic head.
The magnetic recording media of samples A and B were mounted on the magnetic recording apparatus shown in FIGS. 7A and 7B to compare their recording/reproduction characteristics. A thin-film head with a track width of 2.5 μm and a gap length of 0.3 μm was used for recording, and a head of the magneto-resistive effect type with a track width of 2 μm was used for reproduction. At both recording and reproduction, the head was afloat over the medium protection film surface with a clearance of 0.07 μm, with the slider having a relative speed of 11 m/s with respect to the substrate.
Initially, recording at a linear recording density of 20 kFCI was conducted at the room temperature (T=296° K), and next reproduction was conducted at the same temperature. Subsequently, the apparatus was heated to a steady-state temperature of T=350° K in a thermal chamber, and the signal which had been recorded at 20 kFCI at the room temperature was reproduced and compared with the output signal reproduced at room temperature.
The reproduction output at T=350° K normalized by that at the room temperature (T=296° K) was 0.85 in the case of sample A, whereas the counterpart of sample B was as half as 0.51. In addition to the fall of reproduction output due to the temperature rise, the magnitude of noise increased, particularly in the case of sample B. From the viewpoint of S/N characteristics, the degradation of S/N is more pronounced than the output reduction in the case of sample B.
The magnetic recording apparatus in operation has its internal temperature varying depending on the operational environment of the apparatus. It is necessary for the apparatus to meet the operational condition even if its temperature rises. Specifically, the variation of reproduction output signal must be within 30% for the room temperature when the apparatus is at 350° K. This condition is met by sample A of the inventive medium which has an output reduction of about 20%, whereas sample B has its reproduction output falling to a half and does not ensure the normal operation of the apparatus.
Besides the foregoing samples, two other kinds of magnetic recording media were fabricated by using Co—19 at % Cr—10 at % Pt—3 at % Ta and Co—22 at % Cr—10 at % Pt—3 at % Ta for the magnetic film of the magnetic recording layer based on the same film forming process as for sample A. The magnetic recording medium having the magnetic film of Co—19 at % Cr—10 at % Pt—3 at % Ta will be called “sample C”, and the magnetic recording medium having the magnetic film of Co—22 at % Cr—10 at % Pt—3 at % Ta will be called “sample D”.
A transmission electron microscope was used to observe the surface image of magnetic crystal grains of the magnetic film, revealing an average crystal grain size of 11 nm for sample C and 14 nm for sample D. The product Br·t of residual magnetization and film thickness was 50 Gauss·μm for sample C and 85 Gauss·μm for sample D.
Both samples C and D exhibit the normalized saturation magnetization m of 0.75 or more at T=300° K, and it decreases virtually linearly in proportion to T 2 . The constant A of the gradient of slope, the maximum temperature-dependent variation of normalized saturation magnetization m per 1° K in the temperature range of 5° K≦T≦350° K, and the reduction of reproduction output at T=350° K relative to the room temperature were as shown in the following Table 1.
TABLE 1
Variation
Reduction of
Constant A
T1
of m
reproduced signal
Sample C
1.7 × 10 −6
775° K
0.0012
21%
Sample D
2.5 × 10 −6
632° K
0.0018
28%
Sample D is conceived to barely meet the condition for the normal operation of the magnetic disk apparatus in terms of the fall of reproduced signal level caused by the temperature variation.
Embodiment 2:
FIGS. 5A and 5B are brief cross-sectional views showing examples of the inventive and conventional magnetic recording media, respectively, for perpendicular recording. The conventional recording medium has a structure in which a thin film 43 of cobalt alloy is formed as recording layer on a substrate 41 through an orientation control underlayer 42 , with a protection film 44 being formed thereon. In contrast, the inventive recording medium has a structure in which another orientation control underlayer 35 is formed on the conventional orientation control underlayer 32 on the substrate 31 with the intention of improving the crystal orientation, and a magnetic recording film 33 and a protection film 34 are formed on it.
Next, the fabricating procedure of the magnetic recording medium of the inventive structure shown in FIG. 5A will be explained. A cleaned quartz substrate 31 for the 3.5-inch disk was placed on the sputtering device for film formation, the chamber was evacuated to a degree of vacuum of 1×10 −8 Torr or lower, the substrate 31 was heated to 300° C., and it was kept at the steady-state temperature for one hour.
On the substrate 31 , a Ti film (thickness: 30 nm) for the orientation control underlayer 32 and a Ti—15 at % Cr film (thickness: 30 nm) for the orientation control underlayer 35 were formed sequentially. These two underlayers were formed by the d.c. magnetron sputtering process at an Ar gas pressure of 3 mTorr and at a deposition rate of 2 nm/s.
After that, on the resulting multi-underlayer film, a magnetic film (thickness: 50 nm) 33 having an average composition of Co—15 at % Cr—10 at % Pt—3 at % Ta was formed by the ECR sputtering process which is higher in energy at film formation than the d.c. magnetron sputtering process. During the film forming process, the Ar gas pressure was kept at 0.5 mTorr and the d.c. voltage applied to the targets was adjusted so that the deposition rate is 0.3 nm/s.
Subsequently, with the vacuum state being retained, a heat treatment in vacuum was conducted for the resulting thin film sample. Specifically, the heating chamber was evacuated to a degree of vacuum of 5×10 −9 Torr, the substrate with the film formed thereon was heated to a steady-state temperature of 450° C., kept heated for one hour, and cooled down to the room temperature at 25° C./min. After that, a carbon protection film (thickness: 15 nm) 34 was formed on the outmost surface at the room temperature.
All targets except for the C target have a purity of 99.9%, and alloy targets were used to form the alloy thin film. The above-mentioned film composition of each layer was assessed in terms of the average composition of thin film determined based on the scheme of ICPS (Inductively Coupled Plasma Spectroscopy). This sample of medium will be called “sample E” hereinafter.
A conventional magnetic recording medium having a cross-sectional structure shown in FIG. 5B was fabricated in the following manner. Shown is an example of fabrication of a medium having a magnetic film composition of Co—20 at % Cr—8 at % Pt. A cleaned NiP-plated Al alloy disk 41 for the magnetic disk was placed on the sputtering device for film formation, the chamber was evacuated to a degree of vacuum of 1×10 −8 Torr or lower, the substrate 41 was heated to 270° C., and it was kept at the steady-state temperature for one hour. On the substrate 41 , a Ti film (thickness: 50 nm) for the orientation control underlayer 42 , a Co—Cr—Pt magnetic film (thickness: 50 nm) 43 and a carbon protection film 44 were formed sequentially. These thin films were formed by the d.c. magnetron sputtering process at an Ar gas pressure of 3 mTorr.
All targets except for the C target have a purity of 99.9%, and alloy targets were used to form the magnetic film. This sample of medium will be called “sample F” hereinafter.
The fabricated medium samples underwent the assessment of recording/reproduction characteristics, and were thereafter cut into pieces and examined for the film structure and magnetic characteristics. The structure of medium thin film was examined based on the x-ray diffraction scheme. As a result of the θ-2θ x-ray diffraction measurement for samples E and F, the (00.2) surface reflection of the hexagonal close packing structure was observed on the magnetic film. Sample F has a broader peak than sample E.
Although both samples are basically perpendicular magnetic films with their c axis of magnetic film growing in the direction normal to the film surface, the measurement result suggests that sample E has the better c-axis alignment as compared withsample F. A transmission electron microscope was used to observe magnetic crystal grains of the magnetic film, revealing an average crystal grain size of 14 nm for sample E and 16 nm for sample F.
For samples E and F, magnetization curves were plotted at various temperatures ranging from 5° K to 350° K. FIG. 6 shows the temperature-dependent variation of saturation magnetization m normalized by the magnitude of saturation magnetization of each sample at T=5° K. Both samples exhibit the simple decrease of the normalized saturation magnetization with the rise of temperature. Sample F has a greater variation of m=0.68 at T=300° K as compared with m=0.90 at T=300° K of sample E.
When the observation results are treated in terms of the relation of m(T) and T 2 , both samples can be formulated approximately by m(T)=−A·T 2 +B. The constant A is 1.1×10 −6 and the intersection of the slope with the T 2 axis is at T1=930° K in the case of sample E, whereas A is 3.7×10 −6 and T1 is 520° K in the case of sample F. The normalized saturation magnetization m(T) has the largest temperature-dependent variations per 1° K of 0.0008 and 0.0026 for samples E and F, respectively, within the temperature range 5° K≦T≦350° K.
The magnetic recording media having the foregoing magnetic characteristics were mounted in the magnetic recording apparatus shown in FIGS. 7A and 7B thereby to compare their recording/reproduction characteristics. A thin-film head with a track width of 2.5 μm and a gap length of 0.3 μm was used for recording, and a head of the magneto-resistive effect type with a track width of 2 μm was used for reproduction. At both recording and reproduction, the head was afloat over the medium protection film surface with a clearance of 0.07 μm, with the slider having a relative speed of 11 m/s with respect to the substrate.
Initially, recording at a linear recording density of 20 kFCI was conducted at the room temperature (T=296° K), and next reproduction was conducted at the same temperature. Subsequently, the apparatus was heated to a steady-state temperature of T=350° K in a thermal chamber, and the signal which had been recorded at 20 kFCI at the room temperature was reproduced and compared with the output signal reproduced at the room temperature.
The reproduction output at T=350° K normalized by that at the room temperature (T=296° K) was 0.86 in the case of sample E, whereas the counterpart of sample F was as half as 0.54. In addition to the fall of reproduction output due to the temperature rise, the magnitude of noise increased, particularly in the case of sample F. From the viewpoint of S/N characteristics, the degradation of S/N is more pronounced than the output reduction in the case of sample F.
The magnetic recording apparatus in operation has its internal temperature varying depending on the operational environment of the apparatus. It is necessary for the apparatus to meet the operational condition even if its temperature rises. Specifically, the variation of reproduction output signal must be within 30% for the room temperature when the apparatus is at 350° K. This condition is met by sample E of the inventive medium which has an output reduction of about 15%, whereas sample F has its reproduction output falling to a half and does not ensure the normal operation of the apparatus.
The present invention accomplishes the structure of magnetic recording medium having a smaller temperature-dependent variation of saturation magnetization and a smaller temperature-dependent variation of recording/reproduction characteristics, thereby providing a magnetic recording medium which is advantageous to the achievement of high-density recording. | A magnetic recording medium has a magnetic recording film in which the magnitude of saturation magnetization Ms(T=5° K) at 5° K and magnitude of saturation magnetization Ms(T=300° K) at 300° K satisfy: Ms(T=300° K)/Ms(T=5° K)≧0.75. The recording medium enables the high-density recording, and a magnetic recording apparatus using this recording medium can yield a sufficiently high reproduction signal level within the operating temperature range of the apparatus. | 8 |
CROSS-REFERENCE TO PROVISIONAL PATENT APPLICATION
[0001] This application claims priority from U.S. Provisional Application No. 60/834,565 titled “Portable and Compact Grill Apparatus” and filed Jul. 28, 2006, which is incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] Embodiments are generally related to grill devices and systems. Embodiments are also related to portable grill devices.
BACKGROUND OF THE INVENTION
[0003] It is a common practice to barbecue stakes, chops, hot dogs and hamburgers on the grill over a charcoal fire. More recently, the outdoor cookout has begun to include other foods such as those best cooked in a cooking utensil known as a “wok”. The use of the wok involves cooking techniques incorporating a minimum amount of fats and oils. At times vegetables and meats are cooked for a very short time at high heats. The typical stir-fly recipe calls for a cooking time of less then five minutes. Such rapid cooking combined with the use of small quantities of fat provides substantial health benefits because less fat is absorbed in the food compared with traditional Western style frying. In addition, the wok style of cooking tends to seal the flavor into the food, rendering it more appealing to the palate.
[0004] The wok can be easily cleaned and readily reusable for cooking several items on the same menu. The rounded smooth metal surface may be wiped out or dumped for cleaning with little or no residue. Although the wok has many culinary advantages because of its shape, it has fundamental instability problems because of its generally hemispherical shape and relatively small surface on which to rest. The wok was originally developed to be placed directly on hollowed-out sections of coals on the ground and/or on rings with a wide base fire built below. The wok does not adapt well to cooking on modern ranges and as a result a number of devices have been suggested as a substitute for the above mentioned hollowed-out section of coals on the ground.
[0005] One of the problems with the use of a wok in combination with an outdoor grill is that the wok needs a consistent fuel source, such as a propane tank. The propane tanks may be difficult to move in and out of place for efficient heating operations. The wok should be supported in place in order to provide fuel for heating the wok.
BRIEF SUMMARY
[0006] The following summary is provided to facilitate an understanding of some of the innovative features unique to the embodiments disclosed and is not intended to be a full description. A full appreciation of the various aspects of the embodiments can be gained by taking the entire specification, claims, drawings, and abstract as a whole.
[0007] It is therefore, one aspect of the present invention to provide for an improved grill apparatus.
[0008] It is another aspect of the present invention to provide for a compact and portable grill apparatus.
[0009] The aforementioned aspects and other objectives and advantages can now be achieved as described herein. A portable and compact grill apparatus is disclosed, which can be implemented in the form of free standing portable propane fueled cooking device, which utilizes one or more legs (e.g., four legs) to support the cooking surface. The device is constructed to permit a standard propane tank to fit between the legs and directly under the cooking surface. The design permits one of the legs to be removed (by rotating it away from the center) to accommodate the exchange of the propane unit (for refill of fuel). This design creates a very compact unit due to the fact that the fuel tank, burner and cooking surface all fit in a vertical column thus requiring minimal space.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The accompanying figures, in which like reference numerals refer to identical or functionally-similar elements throughout the separate views and which are incorporated in and form a part of the specification, further illustrate the embodiments and, together with the detailed description, serve to explain the embodiments disclosed herein.
[0011] FIG. 1 illustrates a side view of a portable and compact grill apparatus, which can be implemented in accordance with a preferred embodiment;
[0012] FIG. 2 illustrates a top view of the portable and compact grill apparatus depicted in FIG. 1 , in accordance with a preferred embodiment;
[0013] FIG. 3 illustrates a side view of a portable and compact grill apparatus depicting the rotation of one leg to allow removal of a fuel source, in accordance with an alternative embodiment;
[0014] FIG. 4 illustrates a top view of the base plate depicted in FIGS. 1-2 , in accordance with a preferred embodiment;
[0015] FIG. 5 illustrates a side view of a leg, which can be implemented in accordance with an alternative embodiment;
[0016] FIG. 6 illustrates a top view of the top plate depicted in FIGS. 1-2 , in accordance with a preferred embodiment; and
[0017] FIG. 7 illustrates a side view of a portable and compact grill apparatus including a burner and cooking surface, in accordance with a preferred embodiment.
DETAILED DESCRIPTION
[0018] The particular values and configurations discussed in these non-limiting examples can be varied and are cited merely to illustrate at least one embodiment and are not intended to limit the scope thereof.
[0019] FIG. 1 illustrates a side view of a portable and compact grill apparatus 100 , which can be implemented in accordance with a preferred embodiment. The portable grill apparatus 100 generally includes the use of a removable fuel source 102 , which can be provided as, for example, a portable propane fuel tank. Fuel source 102 can thus be a removable propane tank. The apparatus 100 also includes a cooking surface (not shown in FIG. 1 ) associated with a burner (also not shown in FIG. 1 ). The cooking surface and the burner are located proximate to the fuel source 102 , which provides a fuel for heating the cooking surface via the burner. A plurality of legs 104 , 106 can support the cooking surface and the top plate 108 . Additionally, a base plate 114 can be provided which supports the fuel source 102 . The base plate 114 also supports legs 104 , 106 and so forth. The apparatus 100 , including its various components and parts, is preferably formed from a steel material, but it can be appreciated that other types of materials may also be utilized depending upon design considerations.
[0020] The fuel source 102 removably sits between the legs 104 , 106 and directly beneath the cooking surface, which is supported by a top plate 108 . One or more of the legs 104 , 106 is removable in order accommodate an exchange of the fuel source 102 or refuel the fuel source 102 . Each of the legs 104 , 106 can be configured to include respective areas 110 , 112 that provide customized artwork. One or more of the legs 104 , 106 can include a notch such as notch 111 into which the top plate 108 can slide. The notch 111 allows a removable leg 104 or 106 to latch into a secure position, while the other notches can be used to a “fit up” and weld during the production process. Such a notch 111 secures the top plate 108 into a horizontal position and also assists in maintaining a welded connection between the top plate 108 and the leg 106 . In the embodiment depicted in FIG. 1 , the notch 111 can be formed into the area 112 that is configured for customized artwork or functional art placement or designs (e.g., metal artwork or designs). Although the burner and cooking surface (e.g. a work) are not shown in FIG. 1 , it can be appreciated that the fuel source 102 , the burner and the cooking surface can be arranged and located in a vertical column in order to limit spacing thereof and provide for a compact configuration for the portable cooking apparatus.
[0021] FIG. 2 illustrates a top view of the portable and compact grill apparatus 100 depicted in FIG. 1 , in accordance with a preferred embodiment. Note that in FIGS. 1-2 , identical or similar parts or elements are generally indicated by identical reference numerals. In the top view depicted in FIG. 2 , the base plate 114 is illustrated with respect to the legs 104 , 106 which are disposed opposite one another and legs 107 , 109 which are also disposed opposite one another. Four legs 104 , 106 and 107 , 109 are thus shown in FIG. 2 . It can be appreciated that fewer or more legs may be implemented in accordance with alternative embodiments. The top plate 108 is also shown in FIG. 2 with respect to the base plate 114 . One or more of the legs 104 , 106 and 107 , 109 can be removable in order to allow for the installation and removal of the fuel source 102 depicted in FIG. 1 .
[0022] FIG. 3 illustrates a side view of a of a portable and compact grill apparatus 300 , which can be implemented in accordance with an alternative embodiment. The portable grill apparatus 300 generally includes the use of a removable fuel source 302 , which can be provided as, for example, a portable propane fuel tank. Fuel source 302 can thus be a removable propane tank. The apparatus 300 also includes a cooking surface (not shown in FIG. 3 ) associated with a burner (also not shown in FIG. 3 ). The cooking surface and the burner are located proximate to the fuel source 302 , which provides a fuel for heating the cooking surface via the burner. A plurality of legs 304 , 306 can support the cooking surface and the top plate 308 . Note that the legs 304 , 306 depicted in FIG. 3 are analogous to the legs 104 , 106 depicted in FIG. 1 .
[0023] Additionally, a base plate 314 (which is analogous to the base plate 114 of FIG. 1 ) can be provided which supports the fuel source 302 . Arrow 313 depicted in FIG. 3 indicates that the removable legs 304 and/or 306 can be configured to rotate outward from the propane tank or fuel source 302 . Arrow 315 illustrated in FIG. 3 , on the other hand, indicates that after a leg 304 and/or 306 has cleared the notch in the top plate 308 , the leg 304 or 306 can be pulled up and away from the fuel source 302 . Note that the apparatus 300 , including its various components and parts, is preferably formed from a steel material, but it can be appreciated that other types of materials may also be utilized depending upon design considerations.
[0024] The fuel source 302 removably sits between the legs 304 , 306 and directly beneath the cooking surface. One or more of the legs 304 , 306 (which is supported by the base plate 314 and in turn supports the top plate 308 ) is removable in order accommodate an exchange of the fuel source 302 or refuel the fuel source 302 . Each of the legs 304 , 306 can be configured to include respective areas 310 , 312 that provide customized artwork (e.g., functional art). Note that the primary difference between the configuration depicted in FIG. 1 and FIG. 3 is in the presentation of the customized artwork in areas 310 , 312 . FIG. 3 is provided herein to demonstrate that different customized artwork may be available in areas 310 , 312 . Although the burner and cooking surface (e.g. a work) are not shown in FIG. 3 , it can be appreciated that the fuel source 302 , the burner and the cooking surface can be arranged and located in a vertical column in order to limit spacing thereof and provide for a compact configuration for the portable cooking apparatus.
[0025] FIG. 4 illustrates a top view of the base plate 114 depicted in FIGS. 1-2 , in accordance with a preferred embodiment. Note that in FIGS. 1-2 and 4 , identical parts or elements are generally indicated by identical reference numerals. The base plate 114 depicted in FIG. 4 generally includes one or more slots 402 , 404 , 406 , and 408 , which receive one or more of the legs 107 , 104 , 106 , 109 depicted in FIGS. 1-2 . Leg 107 , for example, may slide into slot 402 . The other slots/legs operate with respect to one another in a similar arrangement. Additionally, an area can be provided upon which a company logo 407 or trademark may be placed. Such a logo 407 is, of course, merely optional and is not considered a limiting feature of the disclosed embodiments. Another product logo trademark 409 (e.g., “DISC IT”) can also be cut into the base plate 114 .
[0026] FIG. 5 illustrates a side view of a leg 500 , which can be implemented in accordance with a preferred or alternative embodiment. Note that leg 500 can be implemented in place of or in accordance with legs 107 , 104 , 106 , 109 and/or legs 304 , 306 , depending upon design considerations. Leg 500 generally includes a curved portion 502 that is so shaped to support and the fuel source 102 and/or 302 . Leg 500 includes a tab 506 that can insert into the base plates 114 , 314 . Leg 500 also can be configured to include a notch 508 for the top plates 108 , 308 . The note 508 is similar to the notch 111 depicted in FIG. 1 . A tab 506 generally inserts into the base plate 114 . It can be appreciated that the particular configuration and artwork associated with leg 500 depicted in FIG. 5 represents merely one possible embodiment. Other configurations and designs or artwork may be implemented in accordance with the embodiments disclosed herein without departing from the scope and spirit of the overall concept.
[0027] FIG. 6 illustrates a top view of the top plate 108 depicted in FIGS. 1-2 , in accordance with a preferred embodiment. The top plate incorporates slots 601 , 602 and/or 603 , thereby allowing the burner (not shown in FIG. 6 ) to be bolted to the top plate 108 . The top plate 108 can also be configured to include notches 604 , 605 , 606 and/or 607 , which allow the legs 104 , 106 , 107 and 109 to locate and allow one of the legs (e.g., removable leg 104 , which may includes artwork such as artwork 112 ).
[0028] FIG. 7 illustrates a side view of a portable and compact grill apparatus 700 that includes a burner 704 and a cooking surface 702 , in accordance with an alternative embodiment. Note that in FIGS. 1-7 , identical or similar parts or elements are generally indicated by identical reference numerals. The apparatus 700 generally includes the fuel source 102 (i.e., removable propane tank) and cooking surface 102 (e.g., a Wok-shaped cooking surface) in association with the burner 704 .
[0029] It will be appreciated that variations of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims. | A portable and compact grill apparatus can be implemented in the form of free standing portable propane fueled cooking device, which utilizes one or more legs (e.g., four legs) to support the cooking surface. The device permits a standard propane tank to fit between the legs and directly under the cooking surface. The design permits one of the legs to be removed (by rotating it away from the center) to accommodate the exchange of the propane unit (required for refill of fuel). This design creates a very compact unit due to the fact that the fuel tank, burner and cooking surface all fit in a vertical column thus requiring minimal space. | 0 |
BACKGROUND OF INVENTION
[0001] Wood and composite frame mouldings are most commonly cut or severed at angle and joined by use of a holding device, such as a corner vise, while nails or staples and glues are applied to create a permanent join between lengths or segments. Metal mouldings are more commonly miter cut at 45° and joined using 90° metal corner connecting devices that generally fit within a hidden channel at the middle or back thereof and screws are generally applied to secure the join. Plastic mouldings are generally cut at angle and joined using solvent for permanent joins or are compression fit around the perimeter edges of the framing components thereby forming temporary joins between the individual segments. Some frames are made from a continuous length moulding where angles are 90° V-notch cut and the moulding may or may not be severed into individual segments.
SUMMARY OF THE INVENTION
[0002] The ends of picture frame mouldings are generally factory cut perpendicular at 90° which is defined herein as factory end(s) and custom miter cut, by a framer, which can be costly, leaving ready-made frames which are made in standard sizes such as 8″×10″, 16″×20″, and etc. as the only option, which is not acceptable to many artists.
[0003] U.S. patent application Ser. No. 11/281,992 introduced a new type of foldable picture frame moulding for the creation of custom picture frames from a continuous length using V-notched cuts in the moulding lip body, by non-framers, to make polygon shaped picture frames. It calls for the use of scissors or a blade, which easily repeats factory end cuts, but to cut mitered corners, the process requires too much time, work, and practice to become proficient. Users require a faster, simpler, and easier solution for making acceptable mitered corners when using this new type of moulding.
OBJECT OF INVENTION
[0004] Therefore the object of the present invention is to provide a simpler solution to these problems by using pre-formed angular corner structures to make the frame corners and reduce the amount of time and work needed to complete finished picture frames and provide convertibility and customization.
FIELD OF THE INVENTION
[0005] The present invention provides a new and non-obvious solution to these problems by eliminating the need to V-notch or miter cut the factory ends by using angular corner structures. The angular corner structure provides two hollow perpendicular sleeves or slots or openings and is defined herein as sleeve(s), which receives the factory ends into pre-formed polygon angles commonly found in picture framing structures. The sleeve of the angular corner structure holds the factory end in a temporarily assembled joint by use of friction force pressure applied by hand and is made permanent by the application of a suitable adhesive or solvent thereby eliminating the need for metallic attachment devices.
[0006] The temporarily assembled joints permit a completed frame assembly to be dismantled quickly and easily by the force of pulling it apart, by hand. The sleeve conforms to and surrounds the entire lip body and a portion of an integral perpendicular side wall body of the factory end it receives which allows the depth/height of both the moulding and the side wall body of the angular corner structure to be easily adjusted using scissors or a blade and/or is cold bent using ones hands.
[0007] Each sleeve is terminated by an integral abutment or stop for the factory end and the abutment or stop continues to the vertex corner. The body of the angular corner structure is made using the same resilient copolymer as the moulding described in U.S. Ser. No. 11/281,992 and the wall thickness of the angular corner structure is 0.040″ which is the same thickness as the moulding. The sleeve of the angular corner structure is marginally larger than the structural body thickness of the moulding. The abutment or stop is 0.045″ and is the same thickness as the sleeve.
[0008] The interior surfaces of the angular corner structure provide a natural rabbet or stop or recess or shelf that is common to picture frame moulding and is required to receive picture framing components such as glazing, mat boards, spacers, art objects, backing boards, easel backs, and etc. The surfaces of the angular corner structure may be adorned or customized by the user with an assortment of design elements using an assortment of color treatments, tools, and techniques, including painting or decaling or the simulated miter cuts in the lip face at the vertex of the angular corner structure and the score lines cut into the side wall bodies, as shown in the drawings. The side wall body surfaces may include a plurality of thickness reduced score lines or grooves cut parallel to the perpendicular intersection between the integral lip body and side wall body and are similar to those cut in the moulding which provide assistance to the user when cutting or cold-bending straight lines and to adjust the depth/height of the side wall bodies.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] In the following drawings, which form part of the specification of the present invention, and will be better understood from viewing the following detailed description when combined with the drawings, where:
[0010] FIG. 1 is a top isometric view of the detailed 90° rectangular corner structure;
[0011] FIG. 2 is an interior isometric view of a 60° triangular corner structure;
[0012] FIG. 3 is a top isometric view of prior art U.S. patent application Ser. No. 11/281,992;
[0013] FIG. 4 is an isometric view of FIG. 2 and FIG. 3 joined in a preferred embodiment;
[0014] FIG. 5 is a rear isometric view of FIG. 4 ;
[0015] FIG. 6 is a top elevation view of a 108° pentagonal corner structure;
[0016] FIG. 7 is a top elevation view of a 120° hexagonal corner structure.
[0017] FIG. 8 is a bottom elevation view of a 135° octagonal corner structure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] FIG. 1 shows a preferred detailed embodiment of the invention which is a 90° angle for the creation of rectangular picture frames where 12 shows an exterior lip body surface which is adorned with a simulated miter cut embossed design element 11 and shows an integral perpendicular lip edge body 13 in perpendicular intersection with an inner lip body 12 a which is in perpendicular intersection with an inner side wall body 14 a and 12 is in perpendicular intersection with an integral exterior side wall body 14 which show a plurality of functional thickness reduced score line or groove design elements 15 through 16 . The structural body wall thickness 22 is 0.040″ which is common to all wall bodies. A tightly formed sleeve 19 located between the side wall bodies are in perpendicular intersection with a sleeve opening between the exterior and inner lip bodies 18 , is 0.045″ and is bordered by lip edge body 13 . Functional thickness reduced score line or groove elements 20 through 21 on the interior wall body combined with 15 through 16 on exterior side wall body 14 make it easy for users to follow straight score lines when cutting or making straight line cold-bends to adjust the depth/height of the side wall body 14 . The interior thickness reduced score lines or grooves 20 through 21 are placed in an off-set position from those on the exterior 15 through 16 in an equidistantly spaced pattern.
[0019] FIG. 2 shows an interior view of a triangular corner structure highlighting the inner lip surface 25 in perpendicular intersection with interior wall surface 24 and form the interior rabbet or recess or shelf to stop and hold picture framing components. The sleeves 18 and 19 are terminated by an abutment or stop 23 which continue through 27 to the vertex corner 11 a. Each lip body, sleeve, side wall body, and other elements on each side of 11 or 11 a are identically duplicated on the adjoining integral vertex angular body including the lip body, sleeve, side wall body, and other elements in all embodiments of the invention. Sleeve 18 and 19 are the same thickness as the abutment or stop 23 and 27 .
[0020] FIG. 3 shows prior art, Universal Foldable Frame Moulding, as described in U.S. Ser. No. 11/281,992, where a custom length is shown having two factory ends 33 and 36 . Lip body 31 is normally notch cut using scissors or a blade and side wall body 32 is generally cold-bent perpendicularly to the vertex of a finished notched cut to form an angular side wall corner. The user selectable thickness reduced score lines or grooves 34 through 35 are normally cold-bent or creased horizontally to surround and encapsulate the rear perimeter edges of picture framing components. Factory ends 33 and 36 are pressed into the sleeves in a tight alignment and are held in position temporarily by friction force pressure or made permanent by application of adhesive or solvent, as an alternative to notch cutting to create angular corners.
[0021] FIG. 4 shows the front view of an empty triangular picture frame created by the joining of three equal individual lengths of prior art FIG. 3 where 33 and 36 have been pressed into three individual 60° triangular corner structures at 44 and thereby forming an equilateral triangular picture frame. 46 shows a simulated miter cut design element embossed in the lip body 12 with 44 showing lip body 11 pressed into sleeve 18 . Exterior moulding body 43 and interior moulding body 47 as well as interior side wall body 45 and exterior side wall body 42 of the angular corner structure are unaltered but may be cut or cold-bent or creased inwardly at the rear of an art object and/or picture framing components after these components are inserted into the equilateral triangular picture frame with the art image showing through the front. Score line or groove elements 15 through 16 and 20 through 21 are not shown in this drawing.
[0022] FIG. 5 shows the rear view of FIG. 4 . In a case where the art object is a canvas stretched over wooden stretcher bars (not shown), the assembled frame will convert to create a float frame wherein the inner surfaces 54 , 56 , 47 , and 57 which create the rabbet or recess and shelf are attached to the rear of the wooden stretcher bars and 42 and 43 serve to protect the side walls of the stretched canvas and are not cold-bent but left unaltered where no portion of the moulding or angular corner structure covers any part of the image on the canvas while still providing decoration and protection for the perimeter edges of the stretched canvas. The wall body thicknesses of 27 and 56 provide extra strength and protection for the corners of the art object or picture framing components, which are often damaged during transportation, by the inherent off-setting of 45 and 47 from the side walls of the canvas or picture framing components by the thickness of 14 and 27 . The depth/height of 42 and 43 is optionally reduced by trimming with a blade or scissors as desired.
[0023] FIG. 6 shows the angular corner structure configured to a pentagonal angle 61 of 108° and when five of these angular corner structures are joined or combined with five equal individual lengths of FIG. 3 and pressed together as described in FIG. 4 a pentagonal picture frame is created. 62 shows an outline of the inner location of the abutment or stop which continues to the vertex corner 11 a.
[0024] FIG. 7 shows the angular corner structure configured to a hexagonal angle 71 of 120° and when six of these angular corner structures are joined or combined with six equal individual lengths of FIG. 3 and pressed together as described in FIG. 4 a regular hexagonal picture frame is created. An irregular hexagonal frame is created by preferably lengthening any two opposing or parallel moulding lengths equally prior to assembly. 72 show 62 in this view.
[0025] FIG. 8 shows the angular corner structure configured to an octagonal angle 81 of 135° and when eight of these angular corner structures are joined or combined with eight equal individual lengths of FIG. 3 and pressed together as completed in FIG. 4 a regular octagonal frame is created. An irregular octagonal frame is created by preferably lengthening any two opposing or parallel moulding lengths equally prior to assembly. 89 shows a bottom view of hollow sleeve opening 19 . | Do-It-Yourself angular corner structures that join universal foldable frame moulding lengths, by use of hand pressure, to create triangular, rectangular and other polygon shaped custom picture frames or custom float frames or protective covers, which are made permanent using adhesive or solvent, without the need for metallic attachment devices. | 0 |
This application is a continuation of U.S. application Ser. No. 07/822,233 filed Jan. 27, 1992 now abandoned.
FIELD OF THE INVENTION
The present invention is directed to a method for an optical immunoassay and, more particularly, to a method in which immune reaction reactants are separately labelled with a photoluminescent energy transfer donor and acceptor. The energy transfer resulting when the donor and acceptor are brought into close proximity to each other when the immune reaction occurs produces a detectable luminescence lifetime change.
BACKGROUND OF THE INVENTION
Immunoassays have been based on a variety of methods, including visual and radioactivity determinations. It also is known to optically evaluate immune reactions by using fluorescence intensity measurements. Although fluorescence intensity measurements are desirable in their simplicity, the usefulness of this technique is limited due to problems such as source fluctuations due to noise, drift and the like, fluorophore bleaching, and background fluorescence. Further, if the media is turbid or colored, the intensity measurements will be greatly affected. Moreover, since intensity is a linear product of numerous factors, such as the amount of fluorophore in each state, the excitation intensity, the excitation and emission bandpass, the wavelength sensitivity of the detector, and the like, a complex set of calibration curves must be used to correct for these factors. And finally, a change in the intensity of the probe does not necessarily occur upon binding of antigen and antibody. Thus, while fluorometric intensity measurements can provide useful and highly sensitive results under certain circumstances, they suffer from limited usefulness due to the problems outlined above.
SUMMARY OF THE INVENTION
The present invention provides a method in which a change in the apparent luminescence lifetime of a photoluminescent energy transfer donor or acceptor may be correlated with an immune reaction product. In the context of the present invention, an immune reaction can be considered to occur when there is a specific, non-covalent binding of an antigen with at least one cognizant antibody. The photoluminescent donor and acceptor are carried on immune reaction reactants, so that when an immune reaction occurs, the donor and acceptor can interact, i.e. so that energy transfer occurs between the donor and acceptor, which in turn results in a detectable luminescence lifetime change. By measuring lifetimes, the problems associated with intensity measurements are avoided. The apparent lifetime can be measured by phase-modulation fluorometry or time-resolved fluorometry. By use of this method, immunoassay can be carried out in vivo, in vitro or in situ. Relatively long wavelength fluorescent labels are particularly useful.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 are schematic representations of immune reactions in accordance with a preferred embodiment of the present invention;
FIG. 3 is a graphical representation of apparent lifetime or phase angle v. amount of antigen for one of the immune reactions in FIG. 1;
FIG. 4 is a graphical representation of phase angle and modulation v. frequency for another immune reaction in accordance with a preferred embodiment of the present invention;
FIG. 5 is a graphical representation of phase angle and modulation v. frequency for the immune reaction in FIG. 4 using a different excitation wavelength;
FIG. 6 is a graphical representation of phase angle v. frequency at the excitation wavelengths of FIGS. 3 and 4;
FIG. 7 is a graphical representation of phase angle v. amount of antigen at different frequencies for the immune reaction in FIG. 4;
FIG. 8 is a graphical representation of change in phase angle and modulation for the immune reaction v. frequency for the reaction shown in FIG. 2; and
FIG. 9 is a schematic view showing a preferred embodiment of the instrumentation for use in the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The method of the present invention is capable of determining and quantifying the binding reactions used in immunoassay. In the present method, the reactants of the immune reaction are labelled with a photoluminescent energy transfer donor and acceptor, with at least the donor being photoluminescent. The immune reaction of the labelled reactants brings the donor and acceptor into close proximity so that when the reaction product is excited with radiation, energy transfer occurs between the donor and acceptor, which results in a detectable luminescence lifetime change. Anisotropy or polarization and increased or decreased susceptibility to collisional quenchers are properties which also can be used to detect the lifetime change due to energy transfer. The amount of the reaction product, and thus concentration of either of the reactants, or of a competing reactant in a competitive assay, can be determined also. The present method can be used with a variety of immune reactions, including competitive or non-competitive reactions, and including simple antigen-antibody reactions or various sandwich-type assays. The antigen and/or antibody can be provided with more than one donor or acceptor or label.
The term "sample" is used broadly herein to refer to the immunoassay system in which the immune reaction reactants, e.g. antigen and antibody, are allowed to react. This can include standard laboratory environments such as polymeric supports to which one reactant is bound and in which the second reactant is supplied to the support in solution or suspension. This can include liquid samples and/or suspensions, including blood, urine and secretions. It can also refer to a patient in the case of in vivo testing, which is facilitated by the present invention.
The method of the invention further includes exciting the sample with radiation from any suitable radiation source, such as a continuous wave (CW) laser, electroluminescent lamp, arc lamp, light-emitting diode or a laser diode or the like. Light sources particularly suitable for use in the methods of the present invention include green and red helium-neon lasers, helium-cadmium lasers, a Ti-sapphire laser, an argon ion or Nd:YAG laser synch-pumping a dye laser, and red and infrared laser diodes.
In a preferred embodiment, the intensity of the excitation radiation is modulated at a particular modulation frequency, e.g., sinusoidally, and the lifetime determined using known phase-modulation, i.e., frequency-domain, techniques. Alternatively, a pulsed radiation source such as a square wave light source may be used, and the lifetime of the sample determined using known time-resolved methods. Both phase-modulation and time-resolved fluorometry methods are well known in the prior art, see Lakowicz, Principles of Fluorescence Spectroscopy, Plenum Press, 1983, Chapter 3. However, current instrumentation renders the phase-modulation method more expedient. See Lakowicz in Luminescence Techniques in Chemical and Biochemical Analyses, pp. 141-177, Baeyers, (Keukeleire and Kurkidis, Eds.), 1991, Marcel-Dekker, Inc.; Berndt, Gryczynski and Lakowicz, Reviews of Scientific Instrumentation 1990, 61, pp. 1816-1820; Berndt and Lakowicz, Analytical Biochemistry 1991, in press. For the sake of conciseness, only the phase-modulation method will be discussed further herein, but it is understood that these same principles generally apply to time-resolved measurements.
When the sample is excited with radiation whose intensity is modulated, for example, in a sinusoidal manner, the time lag between absorption and emission causes the emission to be delayed in phase and demodulated relative to the excitation radiation. The phase shift and the corresponding demodulation factor m can be measured and used to calculate the photoluminescent lifetime based on well known formulae. See, Lakowicz, Principles of Fluorescence Spectroscopy, supra. In the present invention, a phase angle difference of about 45 degrees is especially desirable, because if the angle is significantly larger or smaller the accuracy and dynamic range are reduced.
In accordance with the present invention, energy transfer occurs between the photoluminescent energy transfer donor and the photoluminescent energy transfer acceptor, with at least the donor being photoluminescent. Energy transfer between the donor and acceptor causes a change in the fluorescence lifetime corresponding to the presence of the immune reaction. The efficiency of the energy transfer depends on the quantum yield of the donor, the overlapping of the emission spectrum of the donor with the absorption spectrum of the acceptor, and the relative distance and orientation between the donor and the acceptor.
The donors used in the present invention should exhibit good quantum yield, lifetime and extinction coefficient, resistance to collisional quenching and bleaching, and should preferably be water-soluble and easily conjugated to the immune reaction reactant. Particularly desirable are donors which show absorbance and emission in the red and near infrared range, which will be useful in whole blood and living tissue analysis, since they will be free from problems associated with scattering and background fluorescence. Advantageously, relatively inexpensive, modestly powerful and readily-modulated laser diodes can be used as the light source for such donors. The donor will preferably have a lifetime of about 0.1 nanosecond to 1 second, with typical donors being on the order of 1 to 30 nanoseconds, more preferably about 5 ns. Short lived donors will be about 0.1 nanosecond and higher, long-lived donors about 30 to 400 nanoseconds, and lanthanides up to 1 second.
Examples of such donors include cyanines, oxazines, thiazines, porphyrins, phthalocyanines, fluorescent infrared-emitting polynuclear aromatic hydrocarbons such as violanthrones, phycobtliproteins, maleimides, sulfhydryls, isothiocyanates, succinimidyl esters, carbodiimides, sulfonyl chlorides, haloacetyl derivatives, near IR squaraine dyes for example as shown in Dyes and Pigments, 17, pp. 19-27 (1991), and organo-metallic complexes such as the ruthenium and lanthanide complexes of U.S. Pat. Nos. 4,745,076 and 4,670,572, the disclosures of which are incorporated herein by reference. The lanthanide complexes have the advantage of not being quenched by oxygen, and the long lifetimes may allow easy suppression of the autofluorescence of biological samples. Specific materials include fluorescein isothiocyanate (especially fluorescein-5-isothiocyanate), dichlorotriazinylaminofluorescein, teramethylrhodamine-5-(and -6)-isothiocyanate, 1,3-bis-(2-dialkylamino-5-thienyl)-substituted squaraines, the succinimidyl esters of: 5 (and 6)-carboxyfluorescein; 5 (and 6)-carboxytetramethylrhodamine; and 7-amino-4-methylcoumarin-3-acetic acid, ##STR1##
The photoluminescent energy transfer acceptors used in this invention preferably have the properties outlined above with respect to the photoluminescent energy transfer donors, with the exception that the acceptor itself need not necessarily be photoluminescent. Therefore, the classes of compounds listed above for the donors may also be used as acceptors. Additionally, compounds such as azo dyes which absorb at a suitable wavelength can be used as acceptors. The specific compounds identified above may be useful acceptors, along with eosin isothiocyanate, ##STR2##
The immune reaction reactants should be labelled with the donor or acceptor so as to maximize the probability of achieving the desired intra-pair distance and orientation when the immune reaction takes place. This ensures optimal results.
FIG. 1 is a schematic representation of an exemplary embodiment of the present invention. It can be seen that an immune reaction has taken place between the antibody labelled with the donor fluorescein isothiocyanate (FITC) and the antigen labelled with the acceptor eosin isothiocyanate (EOSIN). As a result, the donor and acceptor are brought into sufficiently close proximity to allow energy transfer (schematically represented by the wavy arrow) to take place between the donor and the acceptor. This in turn will result in a detectable change in photoluminescent lifetime of the donor which can be correlated to the amount of labelled antigen if desired. Likewise, the antibody could be labelled with the acceptor and the antigen labelled with the donor if desired. This is shown in FIG. 2, wherein the antigen T 4 is labelled with the donor B-phycoerythrin conjugate and the antibody anti-T 4 IgG(MAb) is labelled with the acceptor CY5.
FIG. 3 is a graphical representation of the relationship between apparent lifetime or phase angle of the FITC-labelled antibody and the amount of the labelled antigen, eosin-IgG, at a frequency of 50 MHz. It can be seen that both the measured phase angle and the derived apparent lifetime decrease with increasing amounts of the antigen (labelled with acceptor).
FIGS. 4 through 7 represent studies done using the antibody goat anti-mouse IgG (an antibody raised in goats to recognize mouse immunoglobulin G), labelled with the donor dichlorotriazinylaminofluorescein ("DTAF-GAMGG") and the antigen mouse IgG, labelled with the acceptor tetramethylrhodamine isothiocyanate ("TRITC-MIGG").
FIG. 4 shows the relationship between phase angle (and modulation) and frequency for DTAF-GAMGG alone and reacted with TRITC-MIGG. The sample was excited with a He/Cd laser at an excitation wavelength of 442 nm. The emission wavelength was 520 nm. The molar ratio of TRITC-MIGG to DTAF-GAMGG was 0.38.
FIG. 5 shows the same relationship as in FIG. 4, except that the laser was a continuous wave frequency-doubled mode-locked Nd:YAG laser synch-pumping a Pyridine 1 dye laser, whose output was frequency-doubled to provide an excitation wavelength of 380 nm.
FIG. 6 shows the relationship between change in phase angle and frequency for the reactions of FIGS. 4 and 5. For both wavelengths, the change in phase angle increases with increasing frequency.
FIG. 7 shows the relationship between phase angle and the amount of antigen for the continuous wave frequency-doubled mode-locked Nd:YAG laser synch-pumping a Pyridine 1 dye laser, modulated at different frequencies as shown. The phase angle decreases with increasing amounts of antigen.
FIG. 8 shows the relationship between phase angle or modulation and frequency for the reaction of FIG. 2, at varying concentrations of acceptor, for the YAG/R6G laser with an excitation wavelength of 560 nm. The emission wavelength was 580 nm.
One preferred embodiment of the instrumentation for use with the method of the invention is schematically shown in FIG. 9. It is to be understood, however, that any suitable instrumentation can be used.
As shown in FIG. 9, radiation source 10, in this case a helium-neon laser having an emission of 543 nm, emits excitation beam 12 which is modulated by acoustooptic modulator 14 at a frequency f1 to create sinusoidally-modulated excitation beam 16. It is to be understood that modulator 14 need not be an acoustooptic modulator, but that any suitable modulator may be used, such as an electrooptic modulator. Moreover, the modulation need not be sinusoidal, but of any desired shape. Also, the modulator need not be external, but instead the light source may be intrinsically modulated, as is known to be possible with laser diodes.
Sinusoidally-modulated excitation beam 16 irradiates sample S, which contains the labelled immune reaction reactants. The irradiated sample emits emitted beam 18 which is detected at photomultiplier tube 20. Alternatively, an avalanche photodiode may be used as the detector, particularly for infrared detection. Emitted beam 18 is amplitude modulated at the same frequency as the excitation but it is phase shifted and demodulated with respect to the excitation. It may be desirable to filter emitted beam 18 with optical filter F in order to change the effective sensitivity range of the detector.
Cross-correlation circuit 22 includes first frequency synthesizer 24 which generates frequency f1, equal to one-half of a modulation frequency fM to drive acoustooptic modulator 14. Cross-correlation circuit 22 also includes second frequency synthesizer 26 which generates a frequency f2 equal to the modulation frequency fM plus a cross-correlation frequency Δ f to drive photomultiplier tube 20. First frequency synthesizer 24 is coupled to frequency doubler 28, which directs a signal having a frequency equal to the modulation frequency fM to mixer 30. Second frequency synthesizer 26 also directs a signal having frequency f2 equal to the modulation frequency fM plus the cross-correlation frequency Δ f to mixer 30. Mixer 30 produces an output signal having a frequency equal to Δ f, the difference between fM and f2.
Mixer 30 and photomultiplier tube 20 are each connected to phase meter/digital voltmeter 32. Phase meter/digital voltmeter 32 compares the output signal having a frequency Δ f received from mixer 30 and the signal having a frequency Δ f(shifted) received from photomultiplier tube 20 to calculate the phase shift φ and the demodulation factor m. The phase shift φ and the demodulation factor m are then stored in computer 34.
The above is for illustrative purposes only. Modifications can be made within the scope of the invention as defined by the appended claims. | A fluorometric luminescence immunoassay method includes forming a sample by exposing a first immune reaction reactant to a second immune reaction reactant capable of reacting with the first reactant, one of the first and second immune reaction reactants being labelled with a photoluminescent energy transfer donor and the other being labelled with a photoluminescent energy transfer acceptor complementary to the photoluminescent donor. At least the photoluminescent donor has the property of photoluminescence, and the photoluminescent donor and acceptor are chosen so that when the first immune reaction reactant reacts with the second immune reaction reactant, the donor and the acceptor are capable of interacting to produce a detectable luminescence lifetime change. The sample is excited with radiation, and the resulting emission is detected. The apparent luminescent lifetime is then calculated to determine the presence of a reaction product of the first and second immune reaction reactants. | 8 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. provisional patent application Ser. No. 62/325,439 filed on Apr. 20, 2016, the disclosure of which is hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a light fixture with an optimized cooling system. The fixture provides efficient and reliable cooling for lights that operate at high temperatures such as Light Emitting Diode (“LED”) grow lights and the like.
BACKGROUND
[0003] LED lighting systems on the market with cooling components operably secured thereto have had limited success. They tend to use extruded, assembled, or otherwise manufactured heat sinks. Many such products have very large footprints because they have dozens or even hundreds of individual LEDs mounted onto large heat sinks with fans blowing air on or around them. The form factors of existing LED lighting products do not maximize cooling with minimal materials. Current product costs are still well above one dollar per watt and product weights run in the range of 5-10 pounds per 100 watts.
[0004] Moreover, they tend to be inefficient and provide limited cooling benefits for the lights and/or consume an excessive amount of energy or other resources to provide the desired cooling effect.
SUMMARY
[0005] Thus, there remains a need for a light fixture for high temperature lights with a fluid cooling system operably secured thereto designed to provide optimal cooling using minimal resources and materials. The fluid may be air, water, coolant or the like. The present invention fulfills these and other needs.
[0006] In disclosed embodiments, the invention achieves improved cooling performance with less material by optimizing the heat sink and fluid flow geometries to create at least one of three possible optimized cooling conditions: First, by forcing fluid to rush through one or more restricting apertures its velocity may be increased by the localized pressure drop. Second, by positioning the heat sink heat exchange structure immediately downstream of the restricting aperture(s) and forcing the fluid flow to change direction while within the confines of the heat exchange structure, the heat transfer may be maximized for the available quantities of fluid flow and heat exchange structure area. Third, the fluid flow may be bifurcated to flow bilaterally through both ends of the heat sink at once in parallel.
[0007] In a disclosed embodiment, heat sinks are made from short sections of an extra wide thermally conductive extrusion material such as aluminum with extra tall and textured fins to maximize the overall system performance. An equally wide restricting aperture slot positioned along the bases of the fins delivers the air flow most effectively. By employing the thermal conductivity of the extruded material to spread the heat across the entire width of the air flow path the heat exchange is maximized while the air flow resistance is minimized.
[0008] By using a plurality of heat sinks with one or more light sources attached to each heat sink, the current invention is intrinsically both scalable and cost effective. This plurality of heat sinks is effectively cooled by a simple air flow plenum design that both balances the cooling between the different heat sinks and spreads and mixes the heat to avoid any hot surface risks.
[0009] These and other objects of the inventions are set forth in more detail in the following description and claims.
FIGURE DESCRIPTIONS
[0010] The foregoing Summary and the following Detailed Description will be better understood when read in conjunction with the accompanying figures.
[0011] FIG. 1 is a schematic diagram of the cooling fluid flow of an embodiment of the current invention.
[0012] FIG. 2 is a cross section schematic view of the cooling fluid flow shown in FIG. 1 showing a possible vacuum-mode of operation.
[0013] FIG. 3 is a cross section schematic view of the cooling fluid flow shown in FIG. 1 showing a possible pressure-mode operation.
[0014] FIG. 4 is an isometric view of a preferred embodiment heat sink for the current invention for providing the cooling fluid flow of FIG. 1 .
[0015] FIG. 5 is a top isometric view of a first exemplar light fixture with optimize cooling system in accordance with an embodiment of the present invention.
[0016] FIG. 6 is a top view of the light fixture with optimized cooling system of FIG. 5 .
[0017] FIG. 7 is a cross-section view of the light fixture with optimized cooling system of FIG. 5 taken along line 7 - 7 of FIG. 6 .
[0018] FIG. 8 is a cross-section view of the light fixture with optimized cooling system of FIG. 5 taken along line 8 - 8 of FIG. 7 .
[0019] FIG. 9 is a top isometric view of a second exemplar light fixture with optimize cooling system in accordance with an embodiment of the present invention.
[0020] FIG. 10 is a top view of the light fixture with optimized cooling system of FIG. 9 .
[0021] FIG. 11 is side view of the light fixture with optimized cooling system of FIG. 9 .
[0022] FIG. 12 is a front view of the light fixture with optimized cooling system of FIG. 9 .
[0023] FIG. 13 is a fragmentary isometric top view of the light fixture with optimized cooling system of FIG. 9 showing possible internal detail.
[0024] FIG. 14 is a cross-section view of the light fixture with optimized cooling system of FIG. 9 taken along line 14 - 14 of FIG. 10 .
[0025] FIG. 15 is a cross section view of the light fixture with optimized cooling system of FIG. 9 taken along line 15 - 15 of FIG. 11 .
[0026] FIG. 16 is an enlarged, fragmentary view of a portion of the light fixture with optimized cooling of FIG. 8 showing possible internal detail.
[0027] FIG. 17 is a schematic view of a possible cooling liquid flow path for use cooling with a light fixture with optimized cooling in accordance with an embodiment of the present invention.
[0028] FIG. 18 is a cross-section view of an extruded thermally conductive material forming flow channels therein for receiving cooling liquid flow therethrough in accordance with an embodiment of the present invention
[0029] FIG. 19 is a partial isometric view of an alternative possible light fixture with optimized cooling in accordance with an embodiment of the present invention showing lighting components installed on the extruded thermally conductive material of FIG. 18 .
DETAILED DESCRIPTION
[0030] A light fixture with optimized cooling system 20 is shown in FIGS. 1-19 . Schematic diagrams of optimized cooling flow paths are shown in FIGS. 1-3 . A preferred possible heat sink 22 for providing the optimized cooling flow paths is shown in FIG. 4 . A first preferred light fixture 20 a is shown in FIGS. 5-8 . A second preferred light fixture 20 b is shown in FIGS. 9-16 , and an alternative preferred cooling system for a third preferred light fixture 20 c is shown in FIGS. 17 - 19 . Each of these structures, systems and related components are discussed in greater detail below.
Optimized Cooling Flow Path
[0031] In general, the fluid cooling flow path 30 through the system is optimized by structures within the path that increase the velocity, number of flow paths, and/or promote turbulent flow adjacent to the high temperature light thereby improving the heat exchange therebetween. Referring to FIG. 1 , a schematic diagram of the cooling fluid flow path 30 , such as air or the like, of the current invention operating in a pressure-mode arrangement is shown. Resistor symbols borrowed from electronic schematics are used to represent the flow head pressure losses of a real fluid cooling system. The flow path 30 is shown as a recirculating circuit even though one of the path legs could be open room air.
[0032] FIG. 1 is a graphical representation with a vertical axis 32 representing positive air pressure in the upward direction. FIG. 1 also has a horizontal axis 34 representing the idea that the fan 40 is not necessarily in the same location as the heat exchange structure of the heat sink 36 . The head pressure 50 provided by the fan 40 gets dissipated by the pressure-side leg 60 of the air flow path defined by the ductwork enclosure as it travels to the restricting aperture and heat exchange structure 70 .
[0033] Next, the air flow with its now reduced head pressure 80 rushes through the restricting aperture and heat exchange structure 70 before returning through the vacuum-side leg 90 of the air flow path and completing the circuit loop. By using the open room air as the vacuum-side air path, air flow resistance is minimized and the back-pressure head 100 is likewise minimized thereby providing a maximum pressure drop across the restricting aperture and heat exchange structure.
[0034] Drawn as a dashed addition, a second restricting aperture/heat exchange structure 110 is shown in parallel to the first. Its head pressure drop is less than the first due to more duct work path length. It is an intention to provide a relatively uniform flow at each heat sink exchange structure by judiciously limiting the aperture sizes in a similar fashion as is already done in the HVAC field. It is also an intention to eventually create very large air flow cooling networks with up to hundreds of individual heat sinks, each with their own restricting aperture for controlling and balancing the many parallel air flow paths.
[0035] FIG. 2 is a cross section view of the current invention showing how a stand-alone, vacuum-mode operating system 21 a of the current invention works. This system is composed of an air moving device, such as a fan 40 , moving air from inside the system enclosure or ductwork system 42 to outside the enclosure or ductwork system. This ejected air 44 is replaced by intake air from a first side 46 and a second side 48 which meet while both are inside the heat exchange structure 70 of the heat sink 22 .
[0036] This intake air flow is controlled and judiciously limited by intentionally designing the shape and size of the restricting apertures 82 and 84 to maximize the overall heat flow. The aperture openings need to be at the bases of the heat exchange fins (in this case) and could generally be less than half the fin height. An improvement can be achieved by adding a porous boundary layer 86 which is shown on the left side of the figure only. The right side shows the same system without the porous boundary layer.
[0037] The air flow arrows 112 show how a porous boundary layer can even out the exit air velocity and increase the average air dwell time within the heat exchange structure by adding a slight resistance. In effect, as much of the kinetic energy of the air velocity as possible is turn into useful heat exchange turbulence. Air flow arrows 120 show how the central region could rush out quickly and the top corners could not see as much cooling air flow without the porous boundary layer.
[0038] Two measures may be taken to avoid dust build-up anywhere near the light emitting surfaces when designing a vacuum-mode system of the current invention. First, the light emitting surfaces are inverted to shine light 130 downwards from an overhead position thereby employing gravity to keep it clean. Second, the vacuum-mode air flow system begins with relative still air 140 moving by only random migration into the intake apertures of the system. This kind of flow generates a minimum amount of dust-stirring-up turbulence and provides a symmetrical initial momentum direction.
[0039] Spreading heat in the third geometric dimension (in and out of the page) is the job of the base 150 of the heat sink. By choosing an extra-wide extrusion shape, this useful heat spreading function adds much more room for longer restricting aperture slots without affecting system costs very much. This also minimizes air resistance.
[0040] FIG. 3 is a cross section view of the current invention showing a pressure-mode operating system. This system is composed of an air moving device, such as a fan 40 , which moves air into the enclosure or ductwork system 42 . The air flow is forced to exit through a restricting aperture slot 114 which is located across the center of the top region of a wide format heat sink 22 . As described for the vacuum mode system above, the heat sink base 150 is used to spread the heat widely in this last orthogonal dimension.
[0041] The air flow speeds up when going through the restricting aperture 114 and then must bifurcate and change direction to exit through the bilateral porous boundaries 116 a and 116 b . The air velocity is relative uniform when exiting due to the slight resistance of the porous boundary layers.
Preferred Heat Sink Structure
[0042] Referring to FIG. 4 , a preferred embodiment heat sink 22 of the current invention is shown. Extruded thermally conductive material such as aluminum is the preferred material for low cost, air cooled systems. Preferred extrusion design features include a very wide extrusion width 150 ; extra tall heat exchanging fin height 152 ; wide air spaces 154 to avoid dust build-up over long term use; a thick base 150 for heat spreading across a wide air flow path; and textured heat exchanging fin surfaces 160 for increased heat transfer performance.
[0043] The cut lengths 162 are minimized to be at least as wide as the light source requires for its mounting and heat transfer performance. Merging of two air flow paths is achieved by drawing air inward through both ends 164 a and 164 b of the heat sink exchange structure, in this case fins, and passing out through the top 166 of the enclosed volume of the heat exchange structure.
[0044] Dashed regions have been drawn to show the preferred locations of the restricting apertures. Dashed region 170 indicates the preferred location for an intake restricting aperture along the base of the heat sink fins 172 when a merging air path is employed. Dashed region 180 indicates the preferred location for the restricting aperture along the central top region of the heat exchange structure when a bifurcating air flow path is employed.
[0045] For systems which also employ a porous barrier layer, a bifurcating system (aka Pressure-Mode) of the current invention could place the porous barrier layer along the entire surface of both ends 182 of the heat exchange structure volume, while a merging system (aka Vacuum Mode) of the current invention could place the porous barrier layer along the entire top surface 184 of the heat exchange structure volume.
Exemplar Air Cooling Systems
[0046] Referring to FIGS. 5-8 , a first possible light fixture 20 a with optimized cooling system is shown. The system includes a substantially H-shaped light weight frame 200 with a plurality (here 4 ) high temperature lights 202 operably secured thereto. The frame 200 includes channels 204 for transmitting fluid, such as air or the like, from an air source, such as a fan 40 , to areas adjacent to the high temperature lights 202 .
[0047] As best sown in FIG. 16 , a heat sink 22 is operably positioned adjacent to each light 202 and fluid exit/entry ports 210 are provided in the frame to allow the cooling fluid to enter or exit the structure through the heat sink as previously described.
[0048] The heat sinks 22 increase the cooling ability of the fluid adjacent to the lights thereby allowing heat from the lights to be efficiently dissipated. The flow rate of the fan need not be particularly large since the heat sinks increase the velocity and turbulent flow adjacent to the lights.
[0049] Referring to FIGS. 9-16 , and a second possible light fixture 20 b with optimized cooling system is shown. This light fixture includes the basic elements of the first possible light fixture, so like elements have been like numbered to avoid undue repetition. It is shown having six lights 202 operably secured thereto with a heat sink 22 operably positioned in the flow path adjacent to each light.
[0050] In can be appreciated that the frame 200 may be enlarged as needed to accommodate as many lights as desired. The size, number and location of the air source such as a cooling fan may need to be adjusted to accommodate the heat load as needed.
[0051] The air source is preferably a fan operably secured to the system. It can be appreciated that cooling air may also be provided by directly tying the light fixture to an existing HVAC system in a building in which the light will be installed.
Water Based Cooling System
[0052] Referring to FIGS. 17-19 , a water-based cooling system for a light fixture 20 c is disclosed. Referring to FIG. 17 , the cooling system 250 may include a closed-loop water, or other liquid coolant, flow path that transmits cooling liquid to the light fixture 20 c and cools the heated cooling liquid prior to its return to the light fixture. A pump 312 delivers cooling fluid from a reservoir 262 to the light fixture 20 c . Heated cooling fluid is returned to the reservoir 262 after either passing by a heat exchanger 270 or after travelling through a cooling path 272 as shown.
[0053] Alternatively, if the cooling fluid is water, it can be exhausted to ambient after it has cooled the light fixture. Because of the improved heat exchange capabilities of the fixture, the volume of water flowing through the system needed to cool the light fixture is minimal.
[0054] Referring to FIGS. 18 & 19 , a water-based cooling liquid fixture frame 300 is shown. The frame 300 includes a water portion 302 for transmitting cooling water therethrough and an electronics mounting portion 304 for operably securing lighting electronics thereto. A thermally conductive and watertight wall 306 separates the water portion from the electronics mounting portion thereby defining a heat exchanger between the cooling water and the electronics such as high temperature lights operably secured within the electronics mounting portion.
[0055] Cooling liquid may flow through the fixture in one direction, or an interior wall 310 may be provided with an opening at one end of the fixture thereby allowing the cooling liquid to flow down one side of the water portion of the frame and return down the opposite side of the water portion.
[0056] Preferably, the frame 300 is formed of a continuous extrusion of a thermally conductive material such as aluminum. Cooling liquid is delivered to the water portion preferably by pump 312 or the like delivering the cooling fluid via a tube 280 running from the water source. Alternatively, if the cooling liquid is water in an open system, the water can be delivered by connecting a hose running from the light fixture to a water source such as a faucet or the like.
[0057] Preferably, the electronics 320 are detachably secured to the frame 300 for easy maintenance and cleaning. One possible attachment structure for the electronics can be spring bale clamps similar to re-useable canning jars provide a consistent clamping force which can be distributed by a clamping adapter matched to the LED array. In this case, the adapter is also a reflector cup to redirect the stray side light into the desire delivery cone angle. Electrical power for the lights and the like can be positioned along the electronics mounting portion as needed. This same structure could also support a lightweight floating ceiling that could move up and down with the light to adjust according to plant height needs.
Use, Operation and Additional Features and Benefits
[0058] Having described the physical features of the invention, its use, benefits and features can include allowing for a complete, stand-alone product with a sales price of less than one dollar per watt for low volume, local based manufacturing. This first product offering delivers a true 300 watts of LED powered illumination with a product weight of less than 7.5 pounds, including the six-foot power cord and full steel enclosure. Future versions can be designed to achieve much lower costs and weights, especially when applied to large scale operations with full HVAC systems. A preferred embodiment could reach costs of less than $0.40 per watt and fixture weights of less than half a pound per 100 watts.
[0059] The primary intended application will be for all types of indoor growing operations, especially the emerging medical and recreational marijuana industries. Customers could be both businesses and private parties, in particular, the first 300-watt product version has been developed to address personal and small commercial operations. The current invention will maximize lighting energy efficiency and minimize operating costs for indoor growing operations.
[0060] This invention can enable at least four different modes of operation:
[0061] First, a stand-alone product can be created using a vacuum-mode system where the plenum or ductwork enclosure is connected to the input side of the air moving device and room air is used for the return air flow path. This arrangement minimizes dust build-up on the light emitting surfaces and thoroughly mixes the outgoing hot air to minimize the creation of any localized hot surfaces. In this case, the air flow also stops when the lights go out so no dust is moved during dark periods.
[0062] Second, a network of many light sources each attached to heat sinks can be effectively cooled together by a pressure-mode system where the plenum or ductwork enclosure is connected to the output side of the air moving device and room air is used for the return vacuum leg of the air flow path. This preferred embodiment allows a single large fan to cool a large plurality of light sources altogether. This air could be pre-filtered and pre-conditioned such as is done for HVAC systems now and that could solve the dust build-up issue even better than vacuum-mode systems. It could also be quieter and cheaper to operate.
[0063] Third, a second return-leg plenum or ductwork enclosure could be added to make the system a closed loop circuit. In this case, the cooling air flow could be kept separate from the room air for situations where that is an advantage. Examples of this include when CO2 enhancement is used to boost growth rates or when rooms are kept sealed to avoid tiny pests getting in.
[0064] Fourth, a liquid could be used instead of air as the cooling fluid. A preferred embodiment has also been created for this application using a continuous aluminum extrusion structure.
[0065] One additional advantage is that the product footprint can be minimized to enable use in greenhouses. By having the smallest footprint possible, the additional lighting does not block the natural sunlight.
[0066] One skilled in the relevant art will recognize that numerous variations and modifications may be made to the configurations described above without departing from the scope of the present invention, as defined by the appended claims. For example, while the primary preferred embodiment is a miniaturized vacuum-mode system intended to function as a stand-alone product for private consumers, another preferred embodiment is created when a full network of pressurized plenum air flow distribution is coupled with electrical power distribution to many heat sinks with light sources attached. In this way, the cooling air could be filtered and clean to avoid the problem of pulling airborne contaminants, like moisture and dust, into the lighting components. Ideally filtered and conditioned HVAC air flow could be used and in this way both the air flow and light could be completely and evenly distributed by a single network structure.
[0067] Another preferred embodiment is created when a second enclosure or duct work network is added to provide a closed loop fluidic cooling system where it is desirable to not mix it with the existing grow room air, such as with carbon dioxide enhancement. | A light fixture for high temperature lights with a fluid cooling system operably secured thereto designed to provide optimal cooling using minimal resources and materials. The fluid may be air, water, coolant or the like. An improved heat sink positioned between the cooling fluid and the light provides optimal fluid flow geometries and creates at least one of three possible optimized cooling conditions: First, by forcing fluid to rush through one or more restricting apertures its velocity may be increased by the localized pressure drop. Second, by positioning the heat sink heat exchange structure immediately downstream of the restricting apertures and forcing the fluid flow to change direction while within the confines of the heat exchange structure. Third, the fluid flow may be bifurcated to flow bilaterally through both ends of the heat sink at once in parallel. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a National Stage of International Application No. PCT/JP2007/065363 filed on Aug. 6, 2007 and which claims priority to Japanese Patent Application No. 2006-325810 filed on Dec. 1, 2006, the entire contents of which are being incorporated herein by reference.
BACKGROUND
[0002] The present application relates to a traction apparatus that is used as a medical treatment device to hoist the neck or waist of a human body and a rope take-up mechanism of the traction apparatus.
[0003] The traction apparatus of FIGS. 5A and 5B shows a conventional mechanism used as a medical treatment machine that hoists the neck or the waist of a human body. FIG. 5A shows a schematic configuration of the traction apparatus. FIG. 5B shows the traction apparatus shown in FIG. 5A as viewed from the direction of arrow “a”.
[0004] In the conventional traction apparatus that is shown in FIG. 5A and FIG. 5B , a traction rope (also simply called a “rope”) 110 that hoists a neck or a waist of a human body in the direction of arrow “c” passes along a pulley C 143 , a pulley B 142 , a pulley D 144 , and a pulley A 141 to be led to a take-up drum 111 . The rotating surface of the pulley D 144 is perpendicularly disposed with respect to the rotating surface of the other pulleys A, B, and C.
[0005] In this way, the conventional traction apparatus causes the load that acts on the traction rope 110 to be transmitted to a rope take-up mechanism that is intricately combined. The load in the direction of arrow “b” applied to the pulley D 144 acts on a coil spring 145 that undergoes linear displacement. The coil spring 145 contracts in proportion to the load, and the displacement is detected as a voltage change of a potentiometer 146 . Thereby, the load on the rope 110 is detected. The center shaft of the take-up drum 111 is joined to a spiral spring (spring) not shown. For that reason, a constant tension always acts on the rope 110 , and a level position of the rope 110 is maintained as shown in FIG. 5A and FIG. 5B without sagging.
[0006] As described above, in the conventional traction apparatus, the rope 110 is bent a number of times by a plurality of pulleys.
[0007] In order for the rope take-up drum 111 to take up the rope 110 in an orderly manner, a winding groove 111 a with a semi-circular shape of the cross-section of the rope is provided in the take-up surface. The rope 110 is taken up on the take-up drum 111 along this winding groove 111 a.
[0008] As a traction apparatus of this type, there has been proposed a sitting traction apparatus that is provided with a sling device for slinging up the underarms of a patient and a seat portion that has a fixture for fixing the thighs, and so by hoisting the seat portion (upper half of the patient's body) vertically, treats the lumbar and the like (for example, refer to Japanese Unexamined Patent Application, First Publication No. 2003-88540).
[0009] As a conventional traction apparatus, there has been proposed a traction apparatus that has a load cell that detects traction force, and along with detecting traction force, is constituted so as to use the detection signal for drive control of a motor that is a drive source of traction force (for example, refer to Japanese Unexamined Patent Application, First Publication No. S59-118156).
[0010] The conventional traction apparatus described above causes the rope 110 to be bent a number of times by the plurality of pulleys. Also, this traction apparatus detects the load on the rope 110 using a coil spring 145 that is attached to the pulley 144 . This results in a structure in which a load is placed on the rope 110 . Also, the winding groove 111 a with a semi-circular shape of the cross-section of the rope is provided in the take-up surface of the take-up drum 111 for the rope 110 . The rope 110 is worn by the edge of this winding groove 111 a , and the life of the rope is shortened. The wearing of the rope 110 leads to the surface of the rope being cut down, whereby rope scraps are generated. As a result of these scraps entering the moving portions of a mechanism, the problem arises of causing malfunction.
SUMMARY
[0011] An object of the present invention thereof is to simplify the rope take-up mechanism that hoists a rope. Moreover, it is possible to provide a traction apparatus and a rope take-up mechanism of a traction apparatus in which there is no wearing of the rope by the edge of the winding groove on the surface of the rope take-up drum as in a conventional drum.
[0012] A traction apparatus according to an embodiment that impresses a desired traction force to a body to be pulled, includes: a traction mechanism that includes a harness coupled to the body to be pulled, a rope having one end attached to the harness, and a take-up drum attaching to an other end of the rope and impressing the traction force on the body to be pulled by taking up the rope; a first pulley that engages at a predetermined wrapping angle the rope to which the traction force is impressed by being taken up by the take-up drum, a rope load being impressed to the first pulley from the rope; a coupling plate that rotatably holds the first pulley, the rope load being impressed to the coupling plate from the first pulley; a load sensor plate that holds the coupling plate at one end portion thereof, the rope load being impressed to the load sensor from the coupling plate; an outer frame that fixes an other end portion of the load sensor plate; and a load cell adhered to a surface of the load sensor plate.
[0013] With this constitution, the first pulley, on which the rope load is impressed from the rope to which the traction force is impressed, is attached to the outer frame via the coupling plate and the load sensor plate without being directly attached to the outer frame. Also, the load cell is adhered to the load sensor plate, and the amount of strain of the load sensor plate due to the rope load is detected with this load cell.
[0014] Thereby, it is possible to detect the rope load that is impressed on the pulley with a simple constitution. It is possible to calculate the load that is being impressed on the body to be pulled from the detection value of this rope load.
[0015] For this reason, it is possible to simplify the rope take-up mechanism of the traction apparatus.
[0016] Also, the aforementioned traction apparatus may include a second pulley that engages the rope closer to the harness than the first pulley.
[0017] Thereby, it is possible to constitute the traction apparatus by using two pulleys. For this reason, it is possible to simplify the rope take-up mechanism of the traction apparatus.
[0018] Also, in the aforementioned traction apparatus, a lengthwise direction of the sensor plate may be a direction that forms equal angles with each of a first movement path of the rope from the second pulley to the first pulley and a second movement path of the rope from the first pulley to the take-up drum.
[0019] With this kind of constitution, the rope load from the first pulley is added parallel to the lengthwise direction of the load sensor plate.
[0020] For this reason, it is possible to effectively detect the rope load at the load sensor plate.
[0021] Also, in the aforementioned traction apparatus, the rope may engage the first pulley so that the first movement path and the second movement path are orthogonal.
[0022] With this kind of constitution, a rope load of √2 times the traction force is applied from the direction that forms a 45° angle with each of the first movement path of the rope from the second pulley to the first pulley and the second movement path of the rope from the first pulley to the take-up drum.
[0023] For this reason, it is possible to more effectively detect the rope load at the load sensor plate.
[0024] Also, in the aforementioned traction apparatus, the rope load may be a tensile load.
[0025] With this kind of constitution, a tensile load acts on the load sensor plate.
[0026] For this reason, it is possible to more effectively detect the rope load at the load sensor plate.
[0027] Also, the aforementioned traction apparatus may include a load sensor mechanism that includes the first pulley, the coupling plate, and the load sensor plate, the load sensor mechanism being constituted to be rotatable in compliance with a rope take-up position of the take-up drum.
[0028] With this kind of constitution, the orientation of the first pulley changes by the load sensor mechanism rotating in compliance with the rope take-up position of the take-up drum.
[0029] Thereby, it is possible to take up the rope in an orderly manner without providing a winding groove on the take-up surface of the take-up drum. For this reason, it is possible to eliminate the problem of the rope wearing on the edge of the winding groove of the surface of the take-up drum, which occurs in a conventional traction apparatus.
[0030] Also, the aforementioned traction apparatus may include a second pulley that engages the rope closer to the harness than the first pulley, the second pulley being constituted to be rotatable in compliance with movement of a first movement path of the rope from the first pulley to the second pulley accompanying rotation of the load sensor.
[0031] With this kind of constitution, the second pulley rotates in compliance with movement of the first movement path that accompanies movement of the second movement path of the rope corresponding to the take-up position of the take-up drum.
[0032] Thereby, it is possible to smooth movement from the first movement path to a third movement path at the second pulley.
[0033] Also, a rope take-up mechanism according to the embodiment of a traction apparatus impressing a desired traction force on a body to be pulled by a harness coupled to the body to be pulled and a rope having one end attached to the harness, includes: a take-up drum that attaches to an other end of the rope and that impresses the traction force on the body to be pulled by taking up the rope; a first pulley that engages at a predetermined wrapping angle the rope to which the traction force is impressed by being taken up by the take-up drum, and on which a rope load is impressed from the rope; a second pulley that engages the rope closer to the harness than the first pulley; and a load sensor mechanism that includes: a coupling plate rotatably holding the first pulley, the rope load being impressed to the coupling plate from the first pulley; a load sensor plate holding the coupling plate at one end portion thereof, the rope load being impressed to the load sensor plate from the coupling plate; an outer frame fixing an other end portion of the load sensor plate; and a load cell adhered to a surface of the load sensor plate.
[0034] With this kind of constitution, the first pulley, on which the rope load that is generated from the rope is impressed, is attached to the outer frame via the coupling plate and the load sensor plate without being directly attached to the outer frame. Also, the load cell is adhered to the load sensor plate, and the strain (strain arising from the rope load) of the load sensor plate due to the rope load is detected with this load cell.
[0035] Thereby, it is possible to detect the rope load that is impressed on the pulley with a simple constitution. It is possible to calculate the load that is being impressed on the body to be pulled from the detection value of this rope load.
[0036] For this reason, it is possible to simplify the rope take-up mechanism of the traction apparatus.
[0037] Also, in the aforementioned rope take-up mechanism of the traction apparatus, wherein a lengthwise direction of the load sensor plate may be a direction that forms equal angles with each of a first movement path of the rope from the second pulley to the first pulley and a second movement path of the rope from the first pulley to the take-up drum.
[0038] Thereby, it is possible to effectively detect the rope load at the load sensor plate.
[0039] Also, in the aforementioned rope take-up mechanism of the traction apparatus, the rope may engage the first pulley so that the first movement path and the second movement path are orthogonal.
[0040] With this kind of constitution, a rope load of √{square root over (2)} times the traction force in the lengthwise direction of the load sensor plate is applied from the direction that forms a 45° angle with each of the first movement path of the rope from the second pulley to the first pulley and the second movement path of the rope from the first pulley to the take-up drum.
[0041] Thereby, it is possible to more effectively detect the rope load at the load sensor plate.
[0042] Also, in the aforementioned rope take-up mechanism of the traction apparatus, the rope load may be a tensile load.
[0043] With this kind of constitution, a tensile load acts on the load sensor plate.
[0044] Thereby, it is possible to more effectively detect the rope load at the load sensor plate.
[0045] Also, in the aforementioned rope take-up mechanism of the traction apparatus, the load sensor mechanism may be constituted to be rotatable in compliance with a rope take-up position of the take-up drum, and the second pulley may be constituted to be rotatable in compliance with movement of a first movement path of the rope from the first pulley to the second pulley accompanying rotation of the load sensor.
[0046] With this kind of constitution, the orientation of the first pulley changes by the load sensor mechanism rotating in compliance with the rope take-up position of the take-up drum. Also, the second pulley rotates in compliance with rotation of the first pulley corresponding to the take-up position of the take-up drum.
[0047] Thereby, it is possible to take up the rope in an orderly manner without providing a winding groove on the rope take-up surface of the take-up drum. For this reason, it is possible to eliminate the problem of the rope wearing on the edge of the winding groove of the surface of the take-up drum, which occurs in a conventional traction apparatus.
[0048] Also, since the second pulley is capable of rotating, it is possible to smooth movement at the second pulley from the first movement path of the rope to a third movement path of the rope that changes in accordance with the take-up position of the take-up drum.
[0049] Accordingly, the traction apparatus according to the embodiment can simplify the rope take-up mechanism that hoists a rope.
[0050] Additional features and advantages of the present application are described in, and will be apparent from, the following Detailed Description and the figures.
BRIEF DESCRIPTION OF THE FIGURES
[0051] FIG. 1 is a view that shows a constitutional example of a traction apparatus according to an embodiment.
[0052] FIG. 2 is a view of a load sensor mechanism of the traction apparatus shown in FIG. 1 as viewed from direction X of FIG. 1 .
[0053] FIG. 3 is a view that shows a rope take-up mechanism according to the embodiment shown in FIG. 1 .
[0054] FIG. 4 is a view that shows a load detection circuit by a load cell according to the embodiment shown in FIG. 1 .
[0055] FIG. 5A is a view that shows an example of a conventional traction apparatus.
[0056] FIG. 5B is a view of the conventional traction apparatus shown in FIG. 5A as viewed from direction a in FIG. 5A .
DETAILED DESCRIPTION
[0057] FIG. 1 shows an example of the traction apparatus according to an embodiment.
[0058] A traction apparatus 1 shown in FIG. 1 is used as a medical treatment device that hoists the neck or waist of a human body. FIG. 1 is a view that shows a schematic constitution of the traction apparatus 1 , and FIG. 2 is a view of a load sensor mechanism of the traction apparatus 1 shown in FIG. 1 as viewed from direction of arrow X.
[0059] In the traction apparatus 1 shown in FIG. 1 , a rope 10 is coupled via a harness 5 to a body to be pulled 2 that is connected to a fixture 3 of a fixing portion 4 . The body to be pulled 2 is schematically shown in FIG. 1 , but is a neck or waist of a patient, or the like.
[0060] In this traction apparatus 1 , the body to be pulled 2 (the traction body such as the neck or waist of the patient) is attached via the harness 5 to one end of the traction rope 10 (also simply called a “rope”). The rope 10 is coupled to a rope take-up drum 11 that holds the other end of the traction rope 10 via a second pulley 13 and a first pulley 12 . The rope 10 is pulled by a traction force that is produced by rotating the take-up drum 11 in the direction of arrow B of FIG. 1 with a motor (not shown).
[0061] The movement path of the rope from one end of the rope 10 that is attached to the harness 5 that is coupled to the body to be pulled 2 to the other end of the rope 10 that is attached to the take-up drum 11 is called the total movement path. This total movement path consists of a first movement path, a second movement path, and a third movement path. The first movement path denotes the movement path of the rope from the second pulley 13 to the first pulley 12 . The second movement path denotes the movement path of the rope from the first pulley 12 to the take-up drum 11 . The third movement path denotes the movement path of the rope from the one end at which the harness 5 is attached to the second pulley 13 .
[0062] The first pulley 12 is fixed to a pair of coupling plates 21 with a bolt 7 A. The coupling plates 21 are attached to a load sensor plate 22 by a bolt 7 B. The load sensor plate 22 is anchored to an outer frame 15 by a bolt 7 C. That is, the pulley 12 is attached to the outer frame 15 via the coupling plates 21 and the load sensor plate 22 , and not directly attached to the outer frame 15
[0063] In the above constitution, a load that is impressed on the rope 10 is applied to the pulley 12 that is attached to the outer frame 15 . A load in a leftward horizontal direction (the direction of arrow H) and a load in an upward vertical direction (the direction of arrow V) are applied to the pulley 12 . Accordingly, since the pulley 12 is coupled with the load sensor plate 22 via the coupling plates 21 , the load that acts on the pulley 12 is applied to the load sensor plate 22 to which a load cell 23 is adhered. The lengthwise direction of the load cell plate 22 is arranged in a direction that forms a 45° angle (angle of arrow D) with the horizontal direction H (the second movement path) and the vertical direction V (first movement path). The magnitudes of the force in this horizontal direction and the force in the vertical direction are equal. Accordingly, the resultant force of the horizontal direction force and the vertical direction force is the load in the direction of A in FIG. 1 . The rope load that acts on the load sensor plate 22 , which is resultant force, is √{square root over (2)} times the load that is impressed on the rope 10 . Here, the rope load refers to the load that is applied to the first pulley 12 from the rope 10 . The rope load is proportional to the traction force that is impressed on the body to be pulled. This proportionality factor is computable from the relation between the direction of the first movement path and the direction of the second movement path added from the rope 10 via the first pulley 12 as mentioned above, and the lengthwise direction of the load sensor plate 22 .
[0064] The lower end part of the load sensor plate 22 is coupled by the bolt 7 C to the outer frame 15 . The outer frame 15 is rotatably installed on a case foundation 17 through a rotary bearing 16 . When strain due to the rope load is produced on the load cell 23 that is adhered to the load sensor plate 22 , the amount of this strain is converted to a voltage signal through a power supply and an amplifier that are connected to the load cell 23 .
[0065] In this traction apparatus 1 , the outer frame 15 is constituted to be rotatable in the direction of arrow C by the rotation mechanism due to the rotary bearing 16 . Accordingly, the outer frame 15 can rotate in agreement with the take-up position of the rope 10 on the take-up surface of the take-up drum 11 . As a result of the second movement path of the rope 10 moving in compliance with the take-up position of the take-up drum 11 , the outer frame 15 can rotate. As a result of the outer frame 15 rotating in this way, the rope 10 can be wound in an orderly manner from an end of the rope take-up drum 11 that has a cylindrical take-up surface with no winding groove. As described above, in the present embodiment, it is possible to use a take-up drum that has a linear take-up cross-section with no winding groove. For this reason, there is no wear on the rope 10 by the edge of a winding groove for rope take-up as in a conventional drum.
[0066] In accordance with the rotation of the outer frame 15 , the first pulley 12 , which is a constituent element of the load sensor mechanism 6 , rotates. Due to this rotation, the first movement path of the rope 10 also moves. Due to the movement of this first movement path, the third movement path of the rope 10 also moves. Here, the second pulley 13 causes the rope 10 to move from the third movement path to the first movement path. This pulley 13 is rotatable in the direction of the arrow E by a rotary bearing 14 . Accordingly, the pulley 13 can rotate in accordance with the movement of the aforementioned first movement path and the third movement path. Due to this rotation, it is possible to make the rope 10 smoothly move from the third movement path to the first movement path at the pulley 13 .
[0067] The center axis of the take-up drum 11 is joined to a spiral spring (spring) not shown. Due to this spiral spring, since a constant tension always acts on the rope 10 , a level position of the rope 10 is maintained as shown in FIG. 1 with no sagging.
[0068] The path to the load that is generated in the traction rope 10 being impressed on the load cell 23 shall be described with reference to FIG. 2 .
[0069] In FIG. 2 , first a load in a 45° direction (direction A in FIG. 1 ) that is added from the traction rope 10 is impressed on the pulley 12 . The rope load that is impressed from this rope is impressed on the coupling plates 21 via the bolt 7 A. The coupling plates 21 are coupled to the load sensor plate 22 via the bolt 7 B. For this reason, the load that is generated in the traction rope 10 is impressed on the load sensor plate 22 . Since the load cell 23 is adhered to the surface of the load sensor plate 22 , strain corresponding to the rope load is generated in the load cell 23 . This strain is converted to resistance change of the load cell 23 . The change in resistance (change of load) of the load cell 23 is detected as a voltage change by the power supply and the amplifier that are connected to the load cell 23 .
[0070] Holes are formed at the portions where the bolt 7 A and the bolt 7 B pass in the side surfaces of the outer frame 15 of the load sensor mechanism 6 , being formed larger than the contour of the bolts 7 A and 7 B. Accordingly, the bolts 7 A and 7 B do not make contact with the outer frame 15 . For this reason, a load that is added to the pulley 12 is not distributed to the outer frame 15 by the bolts 7 A and 7 B.
[0071] The bolt 7 C is coupled to the outer frame 15 . Accordingly, due to the rope load that is added to the load sensor plate 22 , the bolt 7 B and the bolt 7 C pull the load sensor plate 22 in mutually opposite directions. As a result, strain due to the tensile stress is produced in the load sensor plate 22 .
[0072] FIG. 3 is a view that shows the rope take-up mechanism according to the embodiment. FIG. 3 is a view of the traction apparatus 1 shown in FIG. 1 as viewed from the direction of arrow Y.
[0073] In FIG. 3 , the load sensor mechanism 6 includes the first pulley 12 and a mechanism that detects the load added to the pulley 12 with the load cell 23 . The load sensor mechanism 6 rotates by the rotary bearing 16 . The load sensor mechanism 6 rotates in the direction of arrow R in accordance with the position at which the rope 10 on the take-up surface of the take-up drum 11 is wound on the drum (for example, the position of arrow P, the position of arrow Q) as shown in FIG. 3 . By doing so, the rope 10 can be wound on the take-up drum 11 in an orderly manner without miming up on the neighboring rope. The start of winding of the rope 10 on the take-up drum 11 is the right end of the take-up drum surface. At this right end, a hole that passes the rope is provided heading to the center of the take-up drum. The interior of the take-up drum 11 is a pipe-shaped hollow. In this hollow a knot is made at one end of the rope that is inserted from the hole that passes the rope. This knot prevents the rope 10 from being pulled out when being pulled by the motor driving.
[0074] FIG. 4 shows a constitutional example of the load detection circuit by the load cell according to the embodiment. As described above, the rope load that is proportional to the load that acts on the traction rope 10 is added as a force in the pulling direction. The load cell 23 that is adhered to this load sensor plate 22 constitutes a bridge circuit 34 as shown in FIG. 4 . The strain that is produced by the load sensor plate 22 being pulled is transmitted to the load cell 23 . A power supply circuit 31 is provided that supplies a stable fixed voltage to the bridge circuit 34 in order to operate this bridge circuit 34 . Normally a voltage of about 10 V is supplied to the bridge circuit 34 from this power supply circuit 31 . For example, in the case of the input resistance of the bridge circuit 34 being 350Ω, a power supply is used that has a current capacity sufficiently capable of providing a current that flows to this circuit.
[0075] When strain is produced in the load cell 23 , an output voltage 35 of the bridge circuit 34 changes. This change in voltage is input to a direct current amplifier 33 . This input is output after an offset voltage and amplification degree are arbitrarily set, and converted to a voltage signal corresponding to the load output. The motor that rotatively drives the take-up drum 11 is controlled by this voltage signal. In this way, it is possible to obtain the target traction force.
[0076] The present invention can be applied to a traction apparatus that is used as medical treatment device that hoists the neck or the waist of a human body. According to this traction apparatus, it is possible to simplify a rope take-up mechanism that hoists a rope.
[0077] It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present invention and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims. | A traction apparatus which impresses a desired traction force to a body to be pulled is provided. The traction apparatus includes: a traction mechanism that includes a harness coupled to the body to be pulled, a rope having one end attached to the harness, and a take-up drum attaching to an other end of the rope and impressing the traction force on the body to be pulled by taking up the rope; a first pulley that engages at a predetermined wrapping angle the rope to which the traction force is impressed by being taken up by the take-up drum, a rope load being impressed to the first pulley from the rope; a coupling plate that rotatably holds the first pulley, the rope load being impressed to the coupling plate from the first pulley; a load sensor plate that holds the coupling plate at one end portion thereof, the rope load being impressed to the load sensor from the coupling plate; an outer frame that fixes an other end portion of the load sensor plate; and a load cell adhered to a surface of the load sensor plate. | 0 |
RELATED APPLICATION
This application hereby claims priority under 35 U.S.C. §119 to U.S. Provisional Patent Application No. 60/504,116 filed on 18 Sep. 2003, entitled “Motion Artifact Detection and Analysis Tool,” by inventors Eric Boucher and Joseph V. Miseli, and to U.S. Provisional Patent Application No. 60/514,870 filed on 27 Oct. 2003, entitled “Motion Artifact Detection and Analysis Tool,” by inventors Eric Boucher and Joseph V. Miseli.
BACKGROUND
1. Field of the Invention
The present invention relates to video displays. More specifically, the present invention relates to a method and an apparatus for detecting motion-induced artifacts on electronic display systems.
2. Related Art
Liquid Crystal Displays (LCDs) have considerably more difficulty than traditional Cathode Ray Tube (CRT) displays in accurately reproducing moving video images. In recent years, LCDs have advanced beyond CRTs in size and resolution, and are becoming comparable to CRTs in visual performance. During this time, visual performance issues, in which the LCDs lag the CRTs, have been addressed and have been improved significantly. However, until recently, the motion performance of LCDs has been considered, but only basic performance with regard to pixel response time and simple motion artifacts has been addressed.
In determining the performance of LCD displays, many manufacturers qualify the product to assure that motion on the displays is within good engineering bounds. They may do simple image movement testing or response time testing to quantify it. To date, their assessment techniques and options are quite limited.
Until other performance issues were addressed, motion performance issues for LCDs have generally been on the back burner. Now that these other performance issues have been controlled, it is time to deal with motion performance issues in LCDs.
Hence, what is needed is a method and an apparatus for testing motion performance in LCDs and other electronic display systems without the limitations listed above.
SUMMARY
One embodiment of the present invention provides a system that tests the motion performance of an electronic display system, wherein the electronic display system is comprised of a display, graphics processing software, graphics processing circuitry, and an interface coupling the display and the graphics processing circuitry. The system starts by receiving a request to measure an amount of distortion of an object in motion. In response to the request, the system measures the amount of distortion of the object in motion.
In a variation on this embodiment, the system displays a second object and measures the distortion that occurs when the two objects interact.
In a variation on this embodiment, the system receives a request to change a visual attribute of the object. In response to this request, the system changes the visual attribute of the object.
In a further variation, the visual attribute can include color, size, shape, shading, fill pattern, speed, direction of movement, and type of movement.
In a variation on this embodiment, measuring the amount of distortion of the object in motion involves placing a ruler on a boundary of the object where the distortion occurs, increasing the width of the ruler until it covers the distortion, and then measuring the width to determine the size of the distortion.
In a further variation, the ruler is displayed every n th display cycle to minimize distortion of the ruler.
In a further variation, the width of the ruler is used to determine the response time of pixels in the display for any color or gray scale level.
In a variation on this embodiment, the distortion can include flickering, flashing, smearing, bluring, line spreading, geometric distortion, color-induced artifacts, and inaccurate color reproduction.
In a variation on this embodiment, the system stores the set of test parameters to a storage medium to facilitate producing an identical set of test parameters during a subsequent test.
In a variation on this embodiment, the system records the measured distortion on a storage medium. Note that this facilitates in creating a benchmark and a report for a display system under test and provides information for characterizing the display performance over multiple test conditions.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 illustrates a system that tests displays for motion artifacts in accordance with an embodiment of the present invention.
FIG. 2 illustrates the structure of display-testing software in accordance with an embodiment of the present invention.
FIG. 3 illustrates the geometry configuration portion of the display-testing GUI in accordance with an embodiment of the present invention.
FIG. 4 illustrates the color configuration portion of the display-testing GUI in accordance with an embodiment of the present invention.
FIG. 5 illustrates the measurements configuration portion of the display-testing GUI in accordance with an embodiment of the present invention.
FIG. 6 presents a flow chart illustrating the process of testing a display for motion artifacts in accordance with an embodiment of the present invention.
FIG. 7 illustrates measuring a motion-induced artifact in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
The following description is presented to enable any person skilled in the art to make and use the invention, and is provided in the context of a particular application and its requirements. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.
The data structures and code described in this detailed description are typically stored on a computer readable storage medium, which may be any device or medium that can store code and/or data for use by a computer system. This includes, but is not limited to, magnetic and optical storage devices such as disk drives, magnetic tape, CDs (compact discs) and DVDs (digital versatile discs or digital video discs), and computer instruction signals embodied in a transmission medium (with or without a carrier wave upon which the signals are modulated). For example, the transmission medium may include a communications network, such as the Internet.
Display-Testing for Motion Artifacts
FIG. 1 illustrates a system for testing displays for motion artifacts in accordance with an embodiment of the present invention. The system illustrated in FIG. 1 comprises server 104 and client 108 which are coupled to network 100 . Note that server 104 can generally include any computational node including a mechanism for servicing requests from a client for computational and/or data storage resources. Also, note that client 108 can generally include any node on a network including computational capability and including a mechanism for communicating across the network. Network 100 can generally include any type of wire or wireless communication channel capable of coupling together computing nodes. This includes, but is not limited to, a local area network, a wide area network, or a combination of networks. In one embodiment of the present invention, network 100 includes the Internet.
Display 102 is the display that is being tested for motion artifacts. Note that the motion artifacts can be caused by any part of the display system, including graphics processing circuitry, the interface coupling the graphics processing circuitry to the display, and the display itself. Display 102 is coupled to server 104 . Also coupled to server 104 is keyboard 105 and mouse 106 . During the testing process, observer 112 may use GUI 110 on client 108 to manipulate objects on display 102 to test for motion induced artifacts. Additionally, observer 112 may use keyboard 105 and/or mouse 106 to manipulate objects on display 102 .
Display-Testing Software
FIG. 2 illustrates the structure of display-testing software in accordance with an embodiment of the present invention. In one embodiment of the present invention, this software is known as the Motion Artifact Detection and Analysis Tool (MADAT). In this embodiment, MADAT is installed on server 104 , and is comprised of engine 200 , as well as various support modules. These modules can include, network interface module 201 , timer control module 202 , object control module 204 , color control module 206 , analysis module 208 , overlay engine module 210 , file manipulation module 212 , miscellaneous module 214 , and display module 216 .
Network interface module 201 allows engine 200 to communicate with GUI 110 . Note that GUI 110 can exist on any machine coupled to network 100 , or even on server 104 itself.
Overlay engine module 210 allows two objects to be controlled simultaneously in order to test the interaction of two moving objects. Overlay engine module 210 is comprised of an almost identical set of components as the MADAT software itself. For instance, within overlay engine module 210 , you will find a timer control, an object control, and a color control.
Display module 216 takes input from timer control module 202 , object control module 204 , color control module 206 and overlay engine module 210 , and uses these inputs to determine a set of graphical images to output to display 102 , which is the display under test.
GUI—Geometry Configuration
FIG. 3 illustrates the geometry configuration portion of GUI 110 in accordance with an embodiment of the present invention. GUI 110 allows observer 112 to set various attributes related to the geometry of the object being used to test display 102 . These attributes can include oscillation, angle, line attributes, location, dimensions, and shape. Note that in addition to GUI 110 , observer 112 may use the command-line interface with keyboard 105 to implement all of the functionality accessible via GUI 110 . The command-line interface offers additional speed, compactness, and flexibility.
GUI 110 allows observer 112 to take control of virtually every aspect of the visual environment of display 102 . Observer 112 may select from a set of pre-define objects, as well as importing a custom object. In addition, observer 112 may select two objects to additionally test for artifacts caused by the interaction of the two objects.
In one embodiment of the present invention, observer 112 may set the motion type of the object to linear, linear oscillation, or sinusoidal oscillation. During sinusoidal oscillation, the object moves the fastest through the center of oscillation, and the slowest at the end points. In the instances where oscillation is chosen, observer 112 can choose the width and the frequency of oscillation.
Additionally, observer 112 can change the direction of motion as well as the speed. In one embodiment of the present invention, speed is referred to as pixels per refresh, or simply the number of pixels the object moves on the display for each refresh cycle of the display. Since the display size and refresh rate is known to the program, speed can also be expressed in various other terms, such as inches per second.
In one embodiment of the present invention, observer 112 may use GUI 110 , as well as clicking and dragging portions of the object itself to alter the object's geometry.
GUI—Color Configuration
FIG. 4 illustrates the color configuration portion of GUI 110 in accordance with an embodiment of the present invention. GUI 110 allows observer 112 to set various attributes related to the color of the object being used to test display 102 . These attributes can include line colors, foreground colors, background colors, and gradient shading.
Note that it is important to consider color when testing a display for motion-produced artifacts. Since pixels on a display may exhibit different response times to turn on or off for different colors, distortions may not be noticeable for one set of colors, but may be extremely noticeable with another set of colors.
GUI—Measurement Configuration
FIG. 5 illustrates the measurements configuration portion of GUI 110 in accordance with an embodiment of the present invention. GUI 110 allows observer 112 to set various attributes related to the measuring of the artifacts produced on display 102 . These attributes can include the types of measurement rulers, the colors of the rulers, and the deltas of the rulers.
When observer 112 notices an artifact or distortion, observer 112 may choose to measure the distortion by displaying rulers along with the object that is being distorted. In one embodiment of the present invention, one ruler is placed along the leading edge of the moving object, and another ruler is placed on the trailing edge. The rules may be widened, represented by the delta value, to cover the area of the distortion. Once the ruler covers the distortion completely, the delta value indicates the amount of distortion caused by the moving object with a specific set of visual attributes. The delta value can then be used to compute the response times for the pixels under the given visual attributes. Note that the ruler on the leading edge measures the response time for the pixels to turn on, while the trailing edge ruler measures the response time for the pixels to turn off. Note that rulers can be any shape or size including, but not limited to, lines, shapes, background images, and multiple lines. Also note that the rulers may be oriented in any direction and attached to any portion of the artifact.
In one embodiment of the present invention, the rulers may be displayed at every n refresh cycles of display 102 . This allows for greater accuracy in measuring the distortion by minimizing motion artifacts caused by the rulers moving.
Testing Displays for Motion Artifacts
FIG. 6 presents a flow chart illustrating the process of testing a display for motion artifacts in accordance with an embodiment of the present invention. A video image is generated which shows an object moving across display 102 in time. An ideal display will produce the object precisely, with no temporal degradation. Display 102 may have latency, response time limitations, real time processing (timing) difficulties, real-time color rendering delays, and a host of other temporal processing inaccuracies which may contribute to reproducing the content with distortions, or artifacts. The moving object may be visible on display 102 producing artifacts of various types, including flickering, flashing, smearing, distorting, producing inaccurate colors, etc. These are all undesired temporal distortions. Ideally, the object should look exactly the same to observer 112 while the object is in motion and while the object is still. In addition, the object should look the same over time and be free from temporal distortions that are not motion-induced.
The distortion in such a case can be easily observed. However, the characteristics of the human visual system can contribute to some perceptions of distortion that may not actually be generated on display 102 . It is a major part of this program to provide enough tools and control to help definitively assess the motion distortion using other than the eye of observer 112 .
The system starts by producing an image (step 602 ) and displaying the image on display 102 (step 604 ). Note that the image can include a pre-defined image such as a line, a hollow box, a filled box, a hollow ellipse, a filled ellipse, a hollow triangle, a filled triangle, random line patterns, or a custom image that observer 112 imports. Note that different images can produce different types of motion-induced artifacts. Observer 112 views the image (step 606 ) and manipulates the controls that produce the image via GUI 110 , and or keyboard 105 and mouse 106 , (step 608 ). As the image controls are manipulated, the system repeats steps 602 through 608 . Upon discovering a noticeable artifact, the system may analyze the image (step 610 ), or provide adequate control for subjective determination of the artifact by observer 112 .
Note that the motion artifacts can be caused by any part or on any part of the display system. For example, in one embodiment of the present invention, artifacts may be observed that are the result of poor response time for pixels within an LCD display. Artifacts may also result from a flaw in the graphics processing circuitry or the software that generates the images for the display. Furthermore, artifacts may be observed that are the result of characteristics on the transmission lines between the graphics processor and the display such as cross-talk, amplitude dependencies, and skew.
Measuring a Motion-Induced Artifact
FIG. 7 illustrates measuring a motion-induced artifact in accordance with an embodiment of the present invention. Analysis of the image is a combination of the subjective, which requires the input of observer 112 , and numerical analysis which is done by the system itself. Due to the dynamic nature of the system, observer 112 is able to constantly manipulate the attributes of the display system to detect and quantify any number of visual artifacts. In some instances, artifacts might be easily detectable but difficult to quantify, such as flickering of the object. In these cases, the system facilitates in producing artifacts so that subjective analysis and reporting can begin.
One type of numerical analysis is performed by creating guides or rules along portions of the object being displayed. In one embodiment, one ruler (ruler 702 ) is created on the leading edge of moving object 700 , and another ruler (ruler 704 ) is created on the trailing edge. By altering a delta value for each ruler, the width of the rulers can be changed to completely cover the area of distortion on each of the edges of the object. For instance, the delta value can be changed for ruler 702 until it completely covers artifact 706 , and the delta value for ruler 704 can be changed until it completely covers artifact 708 . Theoretically, the delta should remain at zero, even while object 700 is in motion. However, as motion is introduced and the various attributes of object 700 are modified, it is possible to measure the differences as the distortion occurs. This aids in quantifying the distortion in addition to describing the distortion.
The delta of leading edge ruler 702 can be used to quantify the response time for the pixels to turn on for the given set of visual attributes. Likewise, the delta of trailing edge ruler 704 can be used to quantify the response time for the pixels to turn off for the given set of visual attributes. Note that it may be important for the rulers 702 and 704 to be displayed every n th refresh cycle so that distortion of the rulers in motion does not come into play.
The foregoing descriptions of embodiments of the present invention have been presented for purposes of illustration and description only. They are not intended to be exhaustive or to limit the present invention to the forms disclosed. Accordingly, many modifications and variations will be apparent to practitioners skilled in the art. Additionally, the above disclosure is not intended to limit the present invention. The scope of the present invention is defined by the appended claims. | One embodiment of the present invention provides a system that tests the motion performance of an electronic display system, wherein the electronic display system includes a display, graphics processing software, graphics processing circuitry, and an interface coupling the display and the graphics processing circuitry. The system starts by receiving a request to measure an amount of distortion of an object in motion. In response to the request, the system measures the amount of distortion of the object in motion. In a variation on this embodiment, measuring the amount of distortion of the object in motion involves placing a ruler on a boundary of the object where the distortion occurs, increasing the width of the ruler until it covers the distortion, and then measuring the width to determine the size of the distortion. | 6 |
BACKGROUND OF THE INVENTION
This invention is related to rust proofing systems for automobiles, and in particular, a system for encouraging air circulation through body parts which frequently accumulate moisture, water, or mud in inaccessible locations.
Automobile manufacturers construct bodies of thin steel of inexpensive alloy and then strengthen the shell by bracing compartment parts. Water condenses and accumulates in the compartments because they are not ventilated and the interior surfaces are uncoated and unpainted. Surface corrosion follows.
One conventional approach to this problem has been to apply internal preservatives in the body compartments. However, this method still leaves certain areas where traped moisture ultimately forms internal corrosion. For example, many vehicles have a bottom area forward of the front door in which moisture tends to rust out the body. Another vulnerable area is forward of the rear fender.
Another conventional solution has been to provide small bottom openings to permit water to drain, however, such openings are often so designed that water remains trapped in the bottommost part of certain vehicle cavities. Such openings often become plugged with foreign matter.
SUMMARY OF THE INVENTION
The broad purpose of the present invention is to provide removable plugs that encourage the passage of air through certain internal automobile body structures to prevent the accumulation of moisture and water. In the preferred embodiment of the invention, which will subsequently be described in greater detail, a plurality of removable plugs are mounted in appropriately located openings in the body structure. The plugs permit the passage of air for removing moisture from the body structure.
The plugs are removable to permit drainage of water trapped in the body because of blocked drain passages. The removable plugs permit the vehicle owner to easily remove the plugs and flush out the internal body compartments to remove any foreign matter trapping water.
Still further objects and advantages of the invention will be readily apparent to those skilled in the art to which the invention pertains upon reference to the folllowing detailed description.
DESCRIPTION OF THE DRAWING
The description refers to the accompanying drawing in which like reference characters refer to like parts throughout the several views, and in which:
FIG. 1 is a view of an automobile having removable plugs mounted in accordance with the preferred embodiment of the invention;
FIG. 2 is a view of a door having the preferred plugs mounted thereon;
FIG. 3 is an enlarged cross-sectional view through a typical plug mounted in a vertical wall opening;
FIG. 4 is a view taken along lines 4--4 of FIG. 3;
FIG. 5 is a view taken along lines 5--5 of FIG. 3;
FIG. 6 is an enlarged cross-sectional view through a bottom plug; and
FIG. 7 is a view taken along lines 7--7 of FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawing, FIG. 1 illustrates an automotive vehicle 10 having body structure 12. Body structure 12 includes door structure 14 and horizontal molding 15. The body structure is formed of a sheet metal which tends to rust out if not adequately protected.
To protect automobile 10 from rust due to moisture and water, a plug 16 is removably mounted forward of the rear wheel fender, and a plug 18 is removably mounted just forward of the door. Many automobiles rust in these locations because of trapped moisture. The rust action begins on the inside of the sheet metal body structure and progresses outwardly.
Referring to FIG. 2, door 14 has plugs 20 and 22, and a bottom plug 24. Each of the plugs 16, 18, 20, 22, and 24 are removable from their respective locations to permit the user to flush out any foreign deposits that may be internally contained within a body compartment.
Two types of plugs are employed. One is illustrated in FIGS. 3-5 and the other in FIGS. 6-7. Each plug is removable because it can be reduced to a diameter less than the opening in which the plug is mounted.
Plugs 16, 18, 20, and 22 are identical and illustrated in FIGS. 3-5. Referring to FIG. 3, typical plug 22 includes a circular external portion 23 mounted on molding 15 adjacent opening means 28. The diameter of plug portion 23 is greater than the diameter of opening means 28. Portion 23 is formed of a resilient material with a plurality of louvers 30 formed to open in response to air pressure being greater on one side of the louvers than on their opposite side. The louvers close when the pressure on both sides of the wall is balanced.
Plug 22 has an internal portion 32 adjacent opening means 28. Portion 32 is formed such that its diameter is reduced by either pushing into the opening, or removing it from the body. Portion 32 has three slits 34.
The louvers are formed such that when mounted in an external location on the vehicle, the user can rotate the plugs so that the louvers receive air which is then forced through the slits into the internal body portion and create a positive air flow. For example, in FIG. 1, the louvers are directed toward the forward part of the vehicle so that as the vehicle is moving in its forward direction, air is received between the louvers to create a positive air flow.
Similarly, by mounting a pair of plugs on a body structure, such as at 20 and 22, in FIG. 2, the creation of a positive flow of air from one side edge of door 14 toward the opposite side edge tends to remove any accumulation of moist air and thus reduces the tendency of such moisture to condense and form water.
Referring to FIGS. 6 and 7, bottom plug 24 is located in the bottom of the door to drain water received into the door structure. Bottom plug 24 is seated in opening 36 in bottom wall 38. Plug 24 includes an internal body portion 40 having a diameter greater than the diameter of opening 36, and engaging wall 38 closely adjacent opening 36. Plug 24 has an external body portion 42 connected to portion 40, adjacent opening 36. Plug 24 is formed of a resilient material that allows the user to remove the plug from the opening. External portion 42 also has a small opening 44 aligned with an opening 46 in internal body portion 40.
Referring to FIG. 7, portion 40 also has a pair of slots 48 and 50. Slots 48 and 50 each extend from the perimeter of body portion 40 inwardly along the diameter of the body to opening 46. They provide means for water to drain along the internal surface of wall 38 and thereby prevent any water from being trapped in the bottom of the door structure.
Plug 24 can be easily removed from the bottom opening and the interior of the door structure flushed out after extremely wet weather to remove any corrosive materials, such as salt and the like, that may have accumulated in the body. Plug 24 also permits air to pass into the door structure and thereby promote air circulation to prevent any moisture from accumulating in the body and contributing to rust.
The louvers in plugs 20 and 22 permit the user to flush water through the plugs without removing the plugs. The plugs are made in different sizes to accomodate the thickness of the structure in which they are mounted. For example, some plugs are mounted in only a sheet metal opening while others are mounted in a position where the opening is through both the body sheet metal and a molding member. | A system for preventing rust in an automobile body comprising a system of removable plugs which permit the passage of air through certain body structure to prevent the accumulation of moisture or water. | 1 |
This is a continuation of application Ser. No. 07/983,916, Dec. 1, 1992, now abandoned.
FIELD OF THE INVENTION
The present invention relates to a new medical use of, and method of treatment using, the hydroxycarbazole compounds of Formula I, as oxygen radical scavengers, or antioxidants, for protection of vital organs, particularly the cardiovascular system including the heart, from oxidative damage. In particular, the present invention provides a new use for such hydroxycarbazole compounds for making pharmaceutical compositions useful in prevention of organ reperfusion injury including related acute inflammation, particularly cardioprotection, that is, protection of the cardiovascular system from traumatic and post-traumatic injury associated with myocardial infarction. ##STR1## wherein: R 7 -R 13 are independently --H or --OH; and
A=is independently H, --OH, or a moiety of Formula II: ##STR2## wherein: R 1 is hydrogen, lower alkanoyl of up to 6 carbon atoms or aroyl selected from benzoyl and naphthoyl;
R 2 is hydrogen, lower alkyl of up to 6 carbon atoms or arylalkyl selected from benzyl, phenylethyl and phenylpropyl;
R 3 is hydrogen or lower alkyl of up to 6 carbon atoms;
R 4 is hydrogen or lower alkyI of up to 6 carbon atoms, or when X is oxygen, R 4 together with R 5 can represent --CH 2 --O--;
X is a valency bond, --CH 2 , oxygen or sulfur;
Ar is selected from phenyl, naphthyl, indanyl and tetrahydronaphthyl;
R 5 and R 6 are individually selected from hydrogen, fluorine, chlorine, bromine, hydroxyl, lower alkyl of up to 6 carbon atoms, a --CONH 2 -- group, lower alkoxy of up to 6 carbon atoms, benzyloxy, lower alkylthio of up to 6 carbon atoms, lower alkysulphinyl of up to 6 carbon atoms and lower alkylsulphonyl of up to 6 carbon atoms; or
R 5 and R 6 together represent methylenedioxy;
and pharmaceutically acceptable salts thereof.
BACKGROUND OF THE INVENTION
Morbidity and mortality associated with disease-induced ischemic trauma of the vital organs, for instance as seen in acute myocardial infarction, represent major health problems in the developed world.
Considerable biochemical, physiological and pharmacological evidence supports the occurrence and importance of oxygen free radical-induced lipid peroxidation (LPO) in cardiac ischemia/reperfusion injury (Meerson, F. Z. et al., Basic Res. Cardiol. (1982) 77, 465-485; Downey, J. M., Ann. Rev. Physiol. (1990) 52, 487-504). It has been proposed that reoxygenation of ischaemic myocardium leads to generation of O 2 and H 2 O 2 within the tissue which can, in the presence of transition metal ions, become converted into highly-reactive hydroxyl radicals (OH) which initiate LPO, a radical chain reaction, leading to changes in cell membrane integrity and tissue injury (McCord, J. M., N. Engl. J. Med. (1985), 312, 159-163; McCord, J. M., Fed. Proc., (1987) 46, 2402; Kagan, V. E., Lipid Peroxidation in Biomembranes, (1988) CRC Press, Boca Raton Fla.). Marked activation of LPO in experimental myocardial infarction, as well as reoxygenation following transitory ischemia, have been demonstrated (Meerson et al., 1982; Rao et al., Adv. Exp. Med. Biol., (1983) 161,347-363). Exposure of myocytes or whole heart to oxidant-generating systems produced severe injury, including inactivation of the ATP-dependent Ca ++ sequestering system of cardiac sarcoplasmic reticulum (Halliwell, B. and Gutteridge, J. M. C. Free Radicals in Biology and Medicine, 2d ed., (1989) Clarendon Press, Oxford, England, 442-444). A significant increase in plasma LPO levels has also been reported recently in patients with myocardial infarction, especially during the initial 48 hrs after an attack (Loeper et al., Clinica Chimica Acta, (1991) 196, 119-126). The importance of LPO and oxygen radicals in tissue damage associated with ischemia is further supported by the protective effect of natural and synthetic antioxidants such as vitamin E and the lazaroid U-74500A (Levitt, M. A., Clin. Res. (1991) 39, 265A) or antioxidant enzymes such as superoxide dismutase (SOD) and catalase in diverse ischemic models (for review see Halliwell and Gutteridge, 1989).
Given the high incidence of disease-induced ischemic trauma of the vital organs, in particular, of the cardiovascular system including the heart, e.g., together with the high survival rate of patients suffering these traumas in the developed world, there is a great need for pharmaceutical agents which prevent the occurence of such traumas as well as which protect the vital organs of patients in post-traumatic recovery from organ ischemic reperfusion injury.
SUMMARY OF THE INVENTION
In a first aspect, the present invention provides a new medical use for the hydroxycarbazole compounds of Formula I as oxygen radical scavengers or antioxidants for protection of vital organs from oxidative damage. In particular, the present invention provides a new use for compounds preferably selected from the group consisting essentially of the compounds of Formula I wherein A is the moiety of Formula II wherein R1 is --H, R2 is --H, R3 is OH, R4 is --H, X is O, Ar is phenyl, R5 is ortho --OH, and R6 is --H, and one of R 7 , R 9 , or R 10 is --OH, most preferably the compound of Formula I wherein A is the moiety of Formula II wherein R1 is --H, R2 is --H, R3 is --H, R4 is --H, X is O, Ar is phenyl, R5 is ortho --OH, and R6 is --H, and R 7 is --OH, or a pharmaceutically acceptable salt thereof, said compounds being used to make pharmaceutical compositions useful in the prevention of organ reperfusion injury, including related acute inflammation generally, and particularly useful in cardioprotection, that is, protection of the cardiovascular system from traumatic and post-traumatic injury associated with myocardial infarction, in particular, prevention of extensive myocardial infarction and reduction of the area of infarcted myocardial tissue following coronary thrombosis.
In a second aspect, the present invention also provides a method of treatment for prevention of oxidative tissue damage to organs afflicted with disease-induced ischemic trauma, particularly cardioprotection, that is, prevention of stroke and reduction of morbidity resulting from myocardial infarction, in mammals comprising internally administering to a mammal, preferably a human, in need thereof an effective amount of a compound selected from the group consisting essentially of the compounds of Formula I, preferably selected from the group consisting essentially of the compounds of Formula I wherein A is the moiety of Formula II wherein R1 is --H, R2 is OH, R3 is --H, R4 is --H, X is O, Ar is phenyl, R5 is ortho --OH, and R6 is --H, and one of R 7 , R 9 , or R 10 is --OH, most preferably the compound of Formula I wherein A is the moiety of Formula II wherein R1 is --H, R2 is --H, R3 is --H, R4 is --H, X is O, Ar is phenyl, R5 is ortho --OH, and R6 is --H, and R 7 is --OH, or a pharmaceutically acceptable salt thereof.
DETAILED DESCRIPTION OF THE INVENTION
U.S. Pat. No. 4,503,067 discloses carbazolyl-(4)-oxypropanolamine compounds of Formula III: ##STR3## wherein: R 1 is hydrogen, lower alkanoyl of up to 6 carbon atoms or aroyl selected from benzoyl and naphthoyl;
R 2 is hydrogen, lower alkyl of up to 6 carbon atoms or arylalkyl selected from benzyl, phenylethyl and phenylpropyl;
R 3 is hydrogen or lower alkyl of up to 6 carbon atoms;
R 4 is hydrogen or lower alkyl of up to 6 carbon atoms, or when X is oxygen, R 4 together with R 5 can represent --CH 2 --O--;
X is a valency bond, --CH 2 , oxygen or sulfur;
Ar is selected from phenyl, naphthyl, indanyl and tetrahydronaphthyl;
R 5 and R 6 are individually selected from hydrogen, fluorine, chlorine, bromine, hydroxyl, lower alkyl of up to 6 carbon atoms, a --CONH 2 -- group, lower alkoxy of up to 6 carbon atoms, benzyloxy, lower alkylthio of up to 6 carbon atoms, lower alkysulphinyl of up to 6 carbon atoms and lower alkylsulphonyl of up to 6 carbon atoms; or
R 5 and R 6 together represent methylenedioxy;
and pharmaceutically acceptable salts thereof.
This patent further discloses a compound of Formula III, better known as carvedilol (1-(carbazol-4-yloxy-3-[[2-(o-methoxyphenoxy)ethyl]amino]-2-propanol), having the structure shown in Formula IV: ##STR4## These compounds, of which carvedilol is exemplary, are novel multiple action drugs useful in the treatment of mild to moderate hypertension and having utility in angina and congestive heart failure (CHF). Carvedilol is known to be both a competitive β-adrenoceptor antagonist and a vasodilator, and is also a calcium channel antagonist at higher concentrations. The vasodilatory actions of carvedilol result primarily from α 1 -adrenoceptor blockade, whereas the β-adrenoceptor blocking activity of the drug prevents reflex tachycardia when used in the treatment of hypertension. These multiple actions of carvedilol are responsible for the antihypertensive efficacy of the drug in animals, particularly in humans, as well as for utility in the treatment of angina and CHF.
During ischemic organ trauma, as in acute myocardial infarction, a high proportion of ischemic organ cells become irreversibly damaged and necrotic, the extent of injury being dependent upon the length of time that the trauma, e.g. the arterial occlusion, persists. The protection of myocardial cells from such damage and necrosis during occlusion occurring during myocardial infarction and post-infarction reperfusion is essential to achieving the therapeutic goal of restoration of cardiac function; here and throughout this application this property is referred to by the term "cardioprotection" and its synonyms.
While traditional β-adrenoceptor antagonists, for instance propranolol, have a significant cardioprotective effect, they also often have undesireable side effects such as bradycardia, elevated disatolic blood pressure and total peripheral resistance cardiodepression. However, carbazolyl-(4)-oxypropanolamine compounds of Formula III, particularly carvedilol, are effective cardioprotective agents at antihypertensive doses which unexpectedly minimize these consequences. At antihypertensive doses the combination of β-adrenoceptor blocking and vasodilatory properties of carvedilol provides cardioprotection during and after acute myocardial infarction. It is believed that the cardioprotective effects of β-adrenoceptor antagonists at such dosages result from an improvement in the balance between myocardial oxygen supply and demand by reducing myocardial work, which occurs secondary to reductions in both heart rate and contractility.
Some of the compounds of Formula I are known to be metabolites of carvedilol in human and other mammalian (e.g. gerbil) systems. The preferred compounds of the present invention, that is, the compounds of Formula I wherein A is the moiety of Formula II wherein R1 is --H, R2 is --H, R3 is --H, R4 is --H, X is O, Ar is phenyl, R5 is ortho --OH, and R6 is --H, and one of R 7 , R 9 , or R 10 is --OH are known to be metabolites of carvedilol.
We have recently discovered, by use of electron paramagnetic resonance (EPR) studies, that the hydroxycarbazole compounds of Formula I are oxygen radical scavengers. We have also discovered that, as oxygen scavengers, the above-described compounds act to inhibit LPO, and further that the hydroxycarbazole compounds of Formula I are surprisingly effective protective agents in generally preventing a wide variety of disease states associated with oxidative tissue damage to the organs due to LPO following ischemic traumas. In particular, the compounds of the present invention are especially useful in cardioprotection, that is, prevention of acute myocardial infarction, and reduction of morbidity resulting from the sequelae of myocardial infarction and reperfusion.
As is further illustrated below, the compounds of Formula I, preferably selected from the group consisting essentially of the compounds of Formula I wherein A is the moiety of Formula II wherein R1 is --H, R2 is --H, R3 is --H, R4 is --H, X is O, Ar is phenyl, R5 is ortho --OH, and R6 is --H, and one of R 7 , R 9 , or R 10 is --OH, most preferably the compound of Formula I wherein A is the moiety of Formula II wherein R1 is --H, R2 is --H, R3 is --H, R4 is --H, X is O, Ar is phenyl, R5 is ortho --OH, and R6 is --H, and R 7 is --OH, exhibit cardioprotection, and are especially useful for providing a beneficial cardioprotective effect by prevention of oxidative tissue damage in ischemic human myocardium; thus these compounds have utility as adjunctive therapy following myocardial infarction. Chronic administration of these compounds can both reduce the risk of acute myocardial infarction in individuals at risk thereof as well as provide adjunctive therapy by reducing the magnitude of oxidative tissue damage following an ischemic cardiac event. Because hypertensive individuals are at increased risk of stroke, the cardioprotective use of the present compounds at appropriate dosing regimens in combination with antihypertensive therapy significantly reduces the risk of acute myocardial infarction, reinfarction, the area of infarcted tissue should reinfarction occur, and sudden cardiac death in such patients.
The compounds of Formula I, preferably those selected from the group consisting essentially of the compounds of Formula I wherein A is the moiety of Formula II wherein R1 is --H, R2 is --H, R3 is --H, R4 is --H, X is O, Ar is phenyl, R5 is ortho --OH, and R6 is --H, and one of R 7 , R 9 , or R 10 is --OH, most preferably the compound of Formula I wherein A is the moiety of Formula II wherein R1 is --H, R2 is --H, R3 is OH, R4 is --H, X is O, Ar is phenyl, R5 is ortho --OH, and R6 is --H, and R 7 is --OH, are useful for cardioprotection in humans according to the present invention at dosages ranging from about 1-3 mg/kg i.v.b.i.d. and 3-30 .mg/kg p.o. b.i.d.
The present invention also provides a method of treatment for prevention of oxidative tissue damage to organs afflicted with disease-induced ischemic trauma in mammals comprising internally administering to a mammal, preferably a human, in need thereof an effective amount of a compound selected from the group consisting essentially of the compounds of Formula I, preferably those selected from the group consisting essentially of the compounds of Formula I wherein A is the moiety of Formula II, and one of R 7 , R 9 , or R 10 is --OH, most preferably the compound of Formula I wherein A is the the moiety of Formula II, and R 7 is --OH, or a pharmaceutically acceptable salt thereof.
Compounds of Formula I may be conveniently prepared as described by way of example in Example 1.
Pharmaceutical compositions of the compounds of Formulae I for cardioprotective use according to the present invention, may be formulated as solutions or lyophilized powders for parenteral administration. Powders may be reconstituted by addition of a suitable diluent or other pharmaceutically acceptable carder prior to use. The liquid formulation is generally a buffered, isotonic, aqueous solution. Examples of suitable diluents are normal isotonic saline solution, standard 5% dextrose in water or buffered sodium or ammonium acetate solution. Such formulation is especially suitable for parenteral administration, but may also be used for oral administration or contained in a metered dose inhaler or nebulizer for insufflation. It may be desirable to add excipients such as ethanol, polyvinylpyrrolidone, gelatin, hydroxy cellulose, acacia, polyethylene glycol, mannitol, sodium chloride or sodium citrate.
Alternatively, these compounds may be encapsulated, tableted or prepared in a emulsion or syrup for oral administration. Pharmaceutically acceptable solid or liquid carders may be added to enhance or stabilize the composition, or to facilitate preparation of the composition. Liquid carders include syrup, peanut oil, olive oil, glycerin, saline, ethanol, and water. Solid carriers include starch, lactose, calcium sulfate dihydrate, terra alba, magnesium stearate or stearic acid, talc, pectin, acacia, agar or gelatin. The carrier may also include a sustained release material such as glyceryl monostearate or glyceryl distearate, alone or with a wax. The amount of solid carder varies but, preferably, will be between about 20 mg to about 1 g per dosage unit. The pharmaceutical preparations are made following the conventional techniques of pharmacy involving milling, mixing, granulating, and compressing, when necessary, for tablet forms; or milling, mixing and filling for hard gelatin capsule forms. When a liquid carder is used, the preparation will be in the form of a syrup, elixir, emulsion or an aqueous or non-aqueous suspension. Such a liquid formulation may be administered directly p.o. or filled into a soft gelatin capsule.
The following Example is purely illustrative and is provided to teach how to make the compounds of the present invention, but is not intended to limit the scope of the present invention in any manner.
In the Example, all temperatures are in degrees Centigrade (°C.).
EXAMPLES
EXAMPLE 1
The compound of Formula I wherein R7 is --OH, and R8-R13 are all --H, and A is the moiety of Formula II wherein R1 is --H, R2 is --H, R3 is --H, R4 is --H, X is I, Ar is phenyl, R5 is ortho --OH, and R6 is --H was synthesized as follows and is exemplary of the synthetic mute to the compounds of Formula I.
3-Benzyloxy-4-hydroxycarbazole
Benzoyl peroxide (881 mg, 2.73 mmol) was added in one portion to a suspension of 4-hydroxycarbazole (500 mg, 2.73 mmol) in 20 mL ChCl 3 at 25 C. The mixture was stirred for 2 h, then washed with water. The organic layer was dried over sodium sulfate and concentrated. Flash chromatography of the residue (silica, methylene chloride) provided 15 mg of 3-benzyloxy-4-hydroxycarbazole. MS (DCI/NH 3 ): 304.2 (M+H) + .
Subsequent steps to yield the product are well-known: reaction with epichlorohydrin, then 2-methoxyphenethylamine, and finally saponification of the benzoyl ester.
The above description fully discloses how to make and use the present invention. However, the present invention is not limited to the particular embodiment described hereinabove, but includes all modifications thereof within the scope of the following claims. | This invention relates to a new antioxidant use of, and method of treatment using certain hydroxycarbazole compounds or a pharmaceutically acceptable salt thereof. More specifically, the compounds are useful for the prevention of oxidative tissue damage to organs, particularly the central nervous system including the brain, in mammals afflicted with disease-induced ischemic trauma, particularly stroke. | 0 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a Continuation of U.S. patent application Ser. No. 11/608,107 filed Dec. 7, 2006, and claims the benefit under 35 USC 119 of U.S. provisional patent application No. 60/754,272 filed Dec. 29, 2005, both incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
This invention relates generally to shear panels that are applied to framing in residential and other types of light construction. More particularly, the invention relates to panels that are able to resist lateral forces imposed by high wind and earthquake loads in regions where they are required by building codes. Such panels, commonly known as shear walls or diaphragms, must demonstrate shear resistance as shown in recognized tests, such as ASTM E72. These panels may also be used for flooring or roofing or other locations where shear panels are used in residential or commercial construction. The shear panels include one or more reinforcement members bonded to a structural cementitious panel (SCP) to provide a completed panel that can breathe and has weather resistant characteristics to be capable of sustaining exposure to the elements during construction, without damage. The SCP material (continuous phase) of the SCP panel is made from a mixture of inorganic binder and lightweight fillers.
BACKGROUND OF THE INVENTION
Interior residential and light commercial wall and flooring systems commonly include plywood or oriented strand board (OSB) nailed to a wooden frame or mechanically fastened to a metal frame. OSB consists of pieces of wood glued together. Regardless of whether the frame of a building is constructed from wood and/or steel, such frame structures are commonly subjected to a variety of forces. Among the most significant of such forces are gravity, wind, and seismic forces. Gravity is a vertically acting force while wind and seismic forces are primarily laterally acting. Not all sheathing panels are capable of resisting such forces, nor are they very resilient, and some will fail, particularly at points where the panel is fastened to the framing. Where it is necessary to demonstrate shear resistance, the sheathing panels are measured to determine the load which the panel can resist within the allowed deflection without failure.
The shear rating is generally based on testing of three identical 8×8 feet (2.44×2.44 m) assemblies, i.e., panels fastened to framing. One edge is fixed in place while a lateral force is applied to a free end of the assembly until the load is no longer carried and the assembly fails. The measured shear strength will vary, depending upon the thickness of the panel and the size and spacing of the nails or mechanical fasteners used in the assembly. The measured strength will vary as the nail or mechanical fastener size and spacing is changed, as the ASTM E72 test provides. This ultimate strength will be reduced by a safety factor, e.g., typically a factor of two to three, to set the design shear strength for the panel.
As the thickness of the board affects its physical and mechanical properties, e.g., weight, load carrying capacity, racking strength and the like, the desired properties vary according to the thickness of the board.
U.S. Pat. No. 6,620,487 to Tonyan et al., incorporated herein by reference in its entirety, discloses a reinforced, lightweight, dimensionally stable structural cement panel (SCP) capable of resisting shear loads when fastened to framing equal to or exceeding shear loads provided by plywood or oriented strand board panels. The panels employ a core of a continuous phase resulting from the curing of an aqueous mixture of calcium sulfate alpha hemihydrate, hydraulic cement, an active pozzolan and lime, the continuous phase being reinforced with alkali-resistant glass fibers and containing ceramic microspheres, or a blend of ceramic and polymer microspheres, or being formed from an aqueous mixture having a weight ratio of water-to-reactive powder of 0.6/1 to 0.7/1 or a combination thereof. At least one outer surface of the panels may include a cured continuous phase reinforced with glass fibers and containing sufficient polymer spheres to improve nailability or made with a water-to-reactive powders ratio to provide an effect similar to polymer spheres, or a combination thereof.
U.S. Pat. No. 6,241,815 to Bonen, incorporated herein by reference in its entirety, also discloses formulations useful for SCP panels.
One form of wallboard structure purportedly for metal construction applications is disclosed in U.S. Pat. No. 5,768,841 to Swartz et al. That wallboard structure has a metal sheet attached to an entire side of a gypsum panel with an adhesive. Another wallboard panel is disclosed in U.S. Pat. No. 6,412,247 to Menchetti et al. The International Building Code in its “Steel” section also references the use of shear walls utilizing panel type members, i.e., drywall, steel plates and plywood, etc.
US patent application publication no. 2005/0086905 A1 to Ralph et al. discloses shear wall panels and methods of manufacturing shear wall panels. Various embodiments comprise wallboard material employed with a sheet stiffener in the form of a plate to form a wall panel that may be used in applications wherein shear panels are desired.
SUMMARY OF THE INVENTION
The present invention relates to one or more reinforcement members bonded to an SCP panel to provide a completed panel that can breathe and has weather resistant characteristics to be capable of sustaining exposure to the elements during construction, without damage. The SCP material (continuous phase) of the SCP panel is made from a mixture of inorganic binder and lightweight fillers.
In particular, the present invention relates to a panel for resisting shear loads when fastened to framing, comprising: a panel of a continuous phase resulting from the curing of an aqueous mixture comprising, on a dry basis, 35 to 70 weight % reactive powder, 20 to 50 weight % lightweight filler, and 5 to 20 weight % glass fibers, the continuous phase being reinforced with glass fibers and containing the lightweight filler particles, the lightweight filler particles having a particle specific gravity of from 0.02 to 1.00 and an average particle size of about 10 to 500 microns (micrometers); and at least one reinforcing member selected from the group consisting of plate and a mesh sheet attached to a first surface of the continuous phase panel, wherein the at least one reinforcing member covers 5 to 90%, typically 10 to 80%, of the first surface of the continuous phase panel.
Typically, a high strength adhesive such as an epoxy or urethane is applied to a reinforcement member or to indentations on the embossed side of a weather durable SCP panel such sheet of mesh or metal. The reinforcement member is then placed into the indentations on the embossed side of a weather durable SCP panel and then held in a press until the adhesive has cured sufficiently to permit handling the panel without debonding. The finished panel can then be placed on steel or wood framing and attached with either screws or nails. Shear capacity will be determined by the gage of the laminated sheet, size spacing of the fasteners, and the gage and size of the framing members. Typically about 5 to 90%, typically about 10 to 80%, or about 20 to 50% of the embossed side is covered with one or more reinforcement members. If desired the embossing can be omitted such that the reinforcement members protrude from the surface of the SCP panel.
In a first embodiment, a fiber reinforced SCP panel is reinforced with horizontal metal strips 8-12 inches wide laminated along the length of the panel at the edges and mid point of the panel. This reduces the weight of the panel compared to a panel covered with a full sheet of metal. At 12 inches wide the panel typically has about half the steel of a fully laminated panel. The strips allow the panel to breathe and the spacing allows the panel to be adequately supported between the strips. The shear capacity is a function of the gage of metal and width of the strips.
In a second embodiment, the edges of the SCP panel are stiffened by placing metal along the SCP panel edges and bending the metal, e.g., ⅜ inch of metal edge, approximately 90 degrees to form a shallow tray to protect the edges of the SCP panel and add to the lateral fastener pullout strength to resist tear out along edges when the panel is loaded in shear. The term “tear out” means where the fastener tears out a portion of the SCP panel as the panel is racked.
In another embodiment, a reinforced SCP panel is reinforced with diagonal metal plates at the corners to carry the shear and rectangular plates in the field to laterally support the panel against bending out of plane when attached to framing. This embodiment also allows the panel to breathe and reduces the weight of the steel. This embodiment typically has about ⅓ the amount of steel as a fully laminated sheet.
The reinforcement members are typically metal, polymer or mesh. Typical metal sheets are about 0.02 to about 0.07 inches (about 0.05 to about 0.2 cm) thick. The metal is typically steel or aluminum. For example, steel sheets about 25 to 14 gauge, e.g., 22 gauge. The metal can be replaced by one or more about 1/32 to ¼ inch (about 0.08 to about 0.6 cm) thick sheets of polymer, e.g., thermoplastic polymer or thermosetting polymer, or mesh, e.g. fiber glass mesh or carbon fiber mesh.
The present invention also relates to floor or wall systems for residential and light commercial construction including a wooden or metal frame and the reinforced SCP shear panels. Employing a metal frame provides a fully non-combustible system in which all elements pass ASTM E-136. For example, the system may include the reinforced SCP panels employed with a metal framing system employing any standard light-gauge steel C-channels, U-channels, I-beams, square tubing, corrugated metal sheet, and light-gauge prefabricated building sections, such as floor trusses or open web bar joists. The composite SCP panel may be fastened to framing members with either pneumatically driven nails or conventional self-drilling screws.
A wall of reinforced SCP shear panel may have a higher specific racking strength in a shear wall compared to a reinforced concrete masonry shear wall. Specific racking strength is the ultimate racking strength (in pounds per lineal foot) divided by the weight of the wall assembly (in pounds per lineal foot) for a constant wall height. For a given racking strength the present inventive wall is lighter within a practical range of racking strengths than the respective masonry wall of the same racking strength.
The present system having a shear diaphragm on light gauge cold rolled metal frame also is typically water durable. Preferably when testing the system with the SCP panels laid oriented horizontally, the horizontal shear diaphragm load carrying capacity of a system of the present invention will not be lessened by more than 25% (more preferably will not be lessened by more than 20%) when exposed to water in a test wherein a 2 inch head of water is maintained over ¾ inch thick reinforced SCP panels fastened on a 10 foot by 20 foot metal frame for a period of 24 hours. In this test, the 2 inch head is maintained by checking, and replenishing water, at 15 minute intervals.
Preferably the system of the present invention will not absorb more than 0.7 pounds per square foot of water when exposed to water in a test wherein a 2 inch head of water is maintained over ¾ inch thick reinforced SCP panels fastened on a 10 foot by 20 foot metal frame for a period of 24 hours. In this test, the 2 inch head is maintained by checking, and replenishing water, at 15 minute intervals.
Also, the system of the present invention resists swelling due to moisture. Preferably, in the system of the present invention a system of a oriented horizontally 10 foot wide by 20 foot long by ¾ inch thick diaphragm of the reinforced SCP panels attached to a 10 foot by 20 foot metal frame will not swell more than 5% when exposed to a 2 inch head of water maintained over the SCP panels fastened on the metal frame for a period of 24 hours. In this test, the 2 inch head is maintained by checking, and replenishing water, at 15 minute intervals.
Also, the system of the present invention leads to a mold and mildew resistant floor, wall or roof system. Preferably every component of the system of the present invention meets ASTM G-21 in which the system achieves approximately a rating of 1 and meets ASTM D-3273 in which the system achieves approximately a rating of 10. Preferably the system of the present invention supports substantially zero bacteria growth when clean.
A potential advantage of the present system is that, due to its high strength it is better able to provide an earthquake resistant structure.
As the thickness of the board affects its physical and mechanical properties, e.g., weight, load carrying capacity, racking strength and the like, the desired properties vary according to the thickness of the board. Thus, for example, the desired properties which a shear rated panel with a nominal thickness of 0.75 inches (19.1 mm) should meet include the following.
A 4×8 ft, ¾ inch thick panel (1.22×2.44 m, 19.1 mm thick) typically weighs no more than 156 lbs (71 kg) and preferably no more than 144 lbs (65.5 kg). Thinner panels are proportionally lighter.
The present invention provides a method of making the reinforced SCP panel. The present invention provides a method of making systems comprising placing the reinforced SCP panel on one or both sides of metal framing members. The reinforced SCP panels may float on the framing members, for example, joists, or be connected to the framing members mechanically or by adhesive. Connecting the reinforced SCP panels directly or indirectly to the metal framing members may achieve a composite action such that the metal framing and panels work together to carry greater loads.
The present invention also encompasses a non-combustible building system, such as a floor, wall or roof system, including a reinforced SCP panel of the present invention attached to one or both sides of a metal frame to increase the shear capacity of the framed wall.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of a first embodiment of a reinforced structural cementitious panel (SCP) panel of the present invention employing strips of reinforcing sheets inserted in indentations on the SCP material of the panel.
FIG. 2 is a cross-sectional view along view II-II of the panel of FIG. 1 .
FIG. 3 is a top view of a second embodiment of a reinforced SCP panel of the present invention employing strips of reinforcing sheets, including strips which wrap around opposed edges of the panel.
FIG. 4 is a cross-sectional view along view IV-IV of the panel of FIG. 3 .
FIG. 5 is a top view of a third embodiment of a reinforced SCP panel of the present invention wherein the reinforcement strips protrude from a surface of the panel.
FIG. 6 is a cross-sectional view along view VI-VI of the panel of FIG. 5 .
FIG. 7 is a top view of a fourth embodiment of a reinforced SCP panel of the present invention including reinforcing strips which wrap around opposed sidewalls of the panel.
FIG. 8 is a cross-sectional view along view VIII-VIII of the panel of FIG. 7 .
FIG. 9 is a perspective view of a fifth embodiment of a reinforced SCP panel of the present invention including reinforcing mesh which wrap around opposed walls of the panel.
FIG. 10 is a top view of a sixth embodiment of a reinforced SCP panel of the present invention including reinforcing corner pieces and separate optional reinforcing strips.
FIG. 11 is a cross-sectional view along view XI-XI of the panel of FIG. 10 .
FIG. 12 is a cross-sectional view along view XII-XII of the panel of FIG. 10 .
FIG. 13 is a top view of a seventh embodiment of a reinforced SCP panel of the present invention including reinforcing strips and separate reinforcing corner pieces. Optionally, two of the reinforcing strips contact the corner pieces.
FIG. 14 is a cross-sectional view along view XIV-XIV of the panel of FIG. 13 .
FIG. 15 is a cross-sectional view along view XV-XV of the panel of FIG. 13 .
FIG. 16 is a top view of an eighth embodiment of a reinforced SCP panel of the present invention employing a one piece reinforced border on one of its surfaces.
FIG. 17 is a cross-sectional view along view XVII-XVII of the panel of FIG. 16 .
FIG. 18 is a top view of a ninth embodiment of a reinforced SCP panel of the present invention employing a multi-piece reinforced border on one of its surfaces.
FIG. 19 is a top view of a tenth embodiment of a reinforced SCP panel of the present invention employing a perforated panel.
FIG. 20 is a cross-sectional view along view XX-XX of the panel of FIG. 19 .
FIG. 21 is a perspective view of the panel of FIG. 19 .
FIG. 22 is a perspective view of a portion of an eleventh embodiment of a reinforced SCP panel of the present invention employing a panel with small perforations.
FIG. 23 is a top view of a portion of a twelfth embodiment of a reinforced SCP panel of the present invention employing a panel with small perforations.
FIG. 24 is a cross-sectional view along view XXIV-XXIV of the panel of FIG. 23 .
FIG. 25 is a top view of a portion of a thirteenth embodiment of a reinforced SCP panel of the present invention.
FIG. 26 is a cross-sectional view along view XXVI-XXVI of the panel of FIG. 25 .
FIG. 27 is a top view of a portion of a fourteenth embodiment of a reinforced SCP panel of the present invention.
FIG. 28 is a cross-sectional view along view XXVIII-XXVIII of the panel of FIG. 27 .
FIG. 29 is a side view of a multi-layer SCP panel of the present invention with the reinforcement omitted for clarity.
FIG. 30 is a schematic side view of a metal frame wall suitable for employing with a reinforced structural cementitious panel (SCP) panel of the present invention.
FIG. 31 is an elevation view of an apparatus which is suitable for making the SCP panel of the present invention, except for a downstream embossing station and reinforcement attaching station.
FIG. 32 is a perspective view of a slurry feed station of the type used in the present process.
FIG. 33 is a fragmentary overhead plan view of an embedment device suitable for use with the present process to embed lightweight filler.
FIG. 34 shows ASTM E72 Racking data of five 8 foot×8 foot (2.16×2.16 mm) samples with SCP installed horizontally on 16 gauge 3.624 steel studs at 16 inches on center with fastener layout of 6″ (15.2 cm) on center on the perimeter and 12″ (30.4 cm) in the field.
FIG. 35 is a perspective view of a typical metal floor frame 160 suitable for use with the reinforced SCP panels of the present invention.
FIG. 36 is a fragmentary schematic vertical section of a single-layer SCP panel 162 supported on metal frame of FIG. 35 in a system of the present invention.
FIG. 37 is a perspective view of SCP panels of FIG. 36 supported on a corrugated sheet in the non-combustible flooring system of the present invention.
FIG. 38 shows a perspective view of a portion of the embodiment of FIG. 37 wherein SCP panel is attached to corrugated sheet with metal screws.
FIG. 39 shows an embodiment of a roofing system using the reinforced SCP panels of the present invention.
FIG. 40 shows another embodiment of a roofing system using the reinforced SCP panels of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention may employ single layer or multi-layer SCP panels reinforced with reinforcement members such as sheets of metal, polymer or mesh placed on the panel surface. The reinforcement members are typically metal, polymer or mesh, e.g. fiber glass mesh or carbon fiber mesh.
Typical SCP panel material (discussed in more detail elsewhere in this specification) is made from a mixture of water and inorganic binder (examples—gypsum-cement, Portland cement or other hydraulic cements) with the selected lightweight fillers (examples glass fibers, hollow glass microspheres, hollow ceramic microspheres and/or perlite uniformly), and superplasticizer/high-range water reducing admixtures (examples—polynapthalene sulfonates, poly acrylates, etc.) distributed throughout the mixture. Other additives such as accelerating and retarding admixtures, viscosity control additives may optionally be added to the mixture to meet the demands of the manufacturing process involved. The glass fibers can be used alone or in combination with other types of non-combustible fibers such as steel fibers. This results in panels of the present invention which comprise inorganic binder having the selected lightweight fillers distributed throughout the full thickness of the panel.
In the multi-layer SCP panel the layers may be the same or different. For example, the SCP panel may have an inner layer of a continuous phase and at least one outer layer of a continuous phase on each opposed side of the inner layer, wherein at least one outer layer on each opposed side of the inner layer has a higher percentage of glass fibers than the inner layer. This has the ability to stiffen, strengthen and toughen the panel. In another embodiment, a multi-layer panel structure may be created to contain at least one outer layer having improved nailability and cutability by using a higher water-to-reactive powder (defined below) ratio in making the outer layer(s) relative to the core of the panel. A small thickness of the skin coupled with a small dosage of polymer content may improve the nailability without necessarily failing the non-combustibility test. Of course, high dosages of polymer content would lead to failure of the product in the non-combustibility test.
Calcium Sulfate Hemihydrate
Calcium sulfate hemihydrate, which may be used in panels of the invention, is made from gypsum ore, a naturally occurring mineral, (calcium sulfate dihydrate CaSO 4 .2H 2 O). Unless otherwise indicated, “gypsum” will refer to the dihydrate form of calcium sulfate. After being mined, the raw gypsum is thermally processed to form a settable calcium sulfate, which may be anhydrous, but more typically is the hemihydrate, CaSO 4 .½H 2 O. For the familiar end uses, the settable calcium sulfate reacts with water to solidify by forming the dihydrate (gypsum). The hemihydrate has two recognized morphologies, termed alpha hemihydrate and beta hemihydrate. These are selected for various applications based on their physical properties and cost. Both forms react with water to form the dihydrate of calcium sulfate. Upon hydration, alpha hemihydrate is characterized by giving rise to rectangular-sided crystals of gypsum, while beta hemihydrate is characterized by hydrating to produce needle-shaped crystals of gypsum, typically with large aspect ratio. In the present invention either or both of the alpha or beta forms may be used depending on the mechanical performance desired. The beta hemihydrate forms less dense microstructures and is preferred for low density products. The alpha hemihydrate forms more dense microstructures having higher strength and density than those formed by the beta hemihydrate. Thus, the alpha hemihydrate could be substituted for beta hemihydrate to increase strength and density or they could be combined to adjust the properties.
A typical embodiment for the inorganic binder used to make panels of the present invention comprises hydraulic cement such as Portland cement, high alumina cement, pozzolan-blended Portland cement, or mixtures thereof.
Another typical embodiment for the inorganic binder used to make panels of the present invention comprises a blend containing calcium sulfate alpha hemihydrate, hydraulic cement, pozzolan, and lime.
Hydraulic Cement
ASTM defines “hydraulic cement” as follows: a cement that sets and hardens by chemical interaction with water and is capable of doing so under water. There are several types of hydraulic cements that are used in the construction and building industries. Examples of hydraulic cements include Portland cement, slag cements such as blast-furnace slag cement and super-sulfated cements, calcium sulfoaluminate cement, high-alumina cement, expansive cements, white cement, and rapid setting and hardening cements. While calcium sulfate hemihydrate does set and harden by chemical interaction with water, it is not included within the broad definition of hydraulic cements in the context of this invention. All of the aforementioned hydraulic cements can be used to make the panels of the invention.
The most popular and widely used family of closely related hydraulic cements is known as Portland cement. ASTM defines “Portland cement” as a hydraulic cement produced by pulverizing clinker consisting essentially of hydraulic calcium silicates, usually containing one or more of the forms of calcium sulfate as an interground addition. To manufacture Portland cement, an intimate mixture of limestone, argillaceous rocks and clay is ignited in a kiln to produce the clinker, which is then further processed. As a result, the following four main phases of Portland cement are produced: tricalcium silicate (3CaO.SiO 2 , also referred to as C 3 S), dicalcium silicate (2CaO.SiO 2 , called C 2 S), tricalcium aluminate (3CaO.Al 2 O 3 or C 3 A), and tetracalcium aluminoferrite (4CaO.Al 2 O 3 .Fe 2 O 3 or C 4 AF). Other compounds present in minor amounts in Portland cement include calcium sulfate and other double salts of alkaline sulfates, calcium oxide, and magnesium oxide. Of the various recognized classes of Portland cement, Type III Portland cement (ASTM classification) is preferred for making the panels of the invention, because of its fineness it has been found to provide greater strength. The other recognized classes of hydraulic cements including slag cements such as blast-furnace slag cement and super-sulfated cements, calcium sulfoaluminate cement, high-alumina cement, expansive cements, white cement, rapidly setting and hardening cements such as regulated set cement and VHE cement, and the other Portland cement types can also be successfully used to make the panels of the present invention. The slag cements and the calcium sulfoaluminate cement have low alkalinity and are also suitable to make the panels of the present invention.
Fibers
Glass fibers are commonly used as insulating material, but they have also been used as reinforcing materials with various matrices. The fibers themselves provide tensile strength to materials that may otherwise be subject to brittle failure. The fibers may break when loaded, but the usual mode of failure of composites containing glass fibers occurs from degradation and failure of the bond between the fibers and the continuous phase material. Thus, such bonds are important if the reinforcing fibers are to retain the ability to increase ductility and strengthen the composite over time. It has been found that glass fiber reinforced cements do lose strength as time passes, which has been attributed to attack on the glass by the lime which is produced when cement is cured. One possible way to overcome such attack is to cover the glass fibers with a protective layer, such as a polymer layer. In general, such protective layers may resist attack by lime, but it has been found that the strength is reduced in panels of the invention and, thus, protective layers are not preferred. A more expensive way to limit lime attack is to use special alkali-resistant glass fibers (AR glass fibers), such as Nippon Electric Glass (NEG) 350Y. Such fibers have been found to provide superior bonding strength to the matrix and are, thus, preferred for panels of the invention. The glass fibers are monofilaments that have a diameter from about 5 to 25 microns (micrometers) and typically about 10 to 15 microns (micrometers). The filaments generally are combined into 100 filament strands, which may be bundled into rovings containing about 50 strands. The strands or rovings will generally be chopped into suitable filaments and bundles of filaments, for example, about 0.25 to 3 inches (6.3 to 76 mm) long, typically 1 to 2 inches (25 to 50 mm).
It is also possible to include other non-combustible fibers in the panels of the invention, for example, steel fibers are also potential additives.
Pozzolanic Materials
As has been mentioned, most Portland and other hydraulic cements produce lime during hydration (curing). It is desirable to react the lime to reduce attack on glass fibers. It is also known that when calcium sulfate hemihydrate is present, it reacts with tricalcium aluminate in the cement to form ettringite, which can result in undesirable cracking of the cured product. This is often referred to in the art as “sulfate attack.” Such reactions may be prevented by adding “pozzolanic” materials, which are defined in ASTM C618-97 as “ . . . siliceous or siliceous and aluminous materials which in themselves possess little or no cementitious value, but will, in finely divided form and in the presence of moisture, chemically react with calcium hydroxide at ordinary temperatures to form compounds possessing cementitious properties.” One often used pozzolanic material is silica fume, a finely divided amorphous silica which is the product of silicon metal and ferro-silicon alloy manufacture. Characteristically, it has a high silica content and a low alumina content. Various natural and man-made materials have been referred to as having pozzolanic properties, including pumice, perlite, diatomaceous earth, tuff, trass, metakaolin, microsilica, ground granulated blast furnace slag, and fly ash. While silica fume is a particularly convenient pozzolan for use in the panels of the invention, other pozzolanic materials may be used. In contrast to silica fume, metakaolin, ground granulated blast furnace slag, and pulverized fly ash have a much lower silica content and large amounts of alumina, but can be effective pozzolanic materials. When silica fume is used, it will constitute about 5 to 20 wt. %, preferably 10 to 15 wt. %, of the reactive powders (i.e., hydraulic cement, calcium sulfate alpha hemihydrate, silica fume, and lime). If other pozzolans are substituted, the amounts used will be chosen to provide chemical performance similar to silica fume.
Lightweight Fillers/Microspheres
The lightweight panels employed in systems of the present invention typically have a density of 65 to 90 pounds per cubic foot, preferably 65 to 85 pounds per cubic foot, more preferably 72 to 80 pounds per cubic foot. In contrast, typical Portland cement based panels without wood fiber will have densities in the 95 to 110 pcf range, while the Portland Cement based panels with wood fibers will be about the same as SCP (about 65 to 85 pcf).
To assist in achieving these low densities the panels are provided with lightweight filler particles. Such particles typically have an average diameter (average particle size) of about 10 to 500 microns (micrometers). More typically they have a mean particle diameter (mean particle size) from 50 to 250 microns (micrometers) and/or fall within a particle diameter (size) range of 10 to 500 microns. They also typically have a particle density (specific gravity) in the range from 0.02 to 1.00. Microspheres or other lightweight filler particles serve an important purpose in the panels of the invention, which would otherwise be heavier than is desirable for building panels. Used as lightweight fillers, the microspheres help to lower the average density of the product. When the microspheres are hollow, they are sometimes referred to as microballoons.
When the microspheres are hollow, they are sometimes referred to as microballoons.
The microspheres are either non-combustible themselves or, if combustible, added in sufficiently small amounts to not make the SCP panel combustible. Typical lightweight fillers for including in mixtures employed to make panels of the present invention are selected from the group consisting of ceramic microspheres, polymer microspheres, perlite, glass microspheres, and/or fly ash cenospheres.
Ceramic microspheres can be manufactured from a variety of materials and using different manufacturing processes. Although a variety of ceramic microspheres can be utilized as a filler component in the panels of the invention, the preferred ceramic microspheres of the invention are produced as a coal combustion by-product and are a component of the fly ash found at coal fired utilities, for example, EXTENDOSPHERES-SG made by Kish Company Inc., Mentor, Ohio or FILLITE® Brand ceramic microspheres made by Trelleborg Fillite Inc., Norcross, Ga. USA. The chemistry of the preferred ceramic microspheres of the invention is predominantly silica (SiO 2 ) in the range of about 50 to 75 wt. % and alumina (Al 2 O 3 ) in the range of about 15 to 40 wt. %, with up to 35 wt. % of other materials. The preferred ceramic microspheres of the invention are hollow spherical particles with diameters in the range of 10 to 500 microns (micrometers), a shell thickness typically about 10% of the sphere diameter, and a particle density preferably about 0.50 to 0.80 g/mL. The crushing strength of the preferred ceramic microspheres of the invention is greater than 1500 psi (10.3 MPa) and is preferably greater than 2500 psi (17.2 MPa).
Preference for ceramic microspheres in the panels of the invention primarily stems from the fact that they are about three to ten times stronger than most synthetic glass microspheres. In addition, the preferred ceramic microspheres of invention are thermally stable and provide enhanced dimensional stability to the panel of invention. Ceramic microspheres find use in an array of other applications such as adhesives, sealants, caulks, roofing compounds, PVC flooring, paints, industrial coatings, and high temperature-resistant plastic composites. Although they are preferred, it should be understood that it is not essential that the microspheres be hollow and spherical, since it is the particle density and compressive strength which provide the panel of the invention with its low weight and important physical properties. Alternatively, porous irregular particles may be substituted, provided that the resulting panels meet the desired performance.
The polymer microspheres, if present, are typically hollow spheres with a shell made of polymeric materials such as polyacrylonitrile, polymethacrylonitrile, polyvinyl chloride or polyvinylidine chloride, or mixtures thereof. The shell may enclose a gas used to expand the polymeric shell during manufacture. The outer surface of the polymer microspheres may have some type of an inert coating such as calcium carbonate, titanium oxides, mica, silica, and talc. The polymer microspheres have a particle density preferably about 0.02 to 0.15 g/mL and have diameters in the range 10 to 350 microns (micrometers). The presence of polymer microspheres may facilitate simultaneous attainment of low panel density and enhanced cutability and nailability.
Other lightweight fillers, for example glass microspheres, perlite or hollow alumino-silicate cenospheres or microspheres derived from fly ash, are also suitable for including in mixtures in combination with or in place of ceramic microspheres employed to make panels of the present invention.
The glass microspheres typically are made of alkali resistant glass materials and may be hollow. Typical glass microspheres are available from GYPTEK INC., Suite 135, 16 Midlake Blvd SE, Calgary, AB, T2X 2X7, CANADA.
In a first embodiment of the invention, only ceramic microspheres are used throughout the full thickness of the panel. The panel typically contains about 35 to 42 weight % of ceramic microspheres uniformly distributed throughout the thickness of the panel.
In a second embodiment of the invention, a blend of lightweight ceramic and glass microspheres is used throughout the full thickness of the panel. The volume fraction of the glass microspheres in the panel of the second embodiment of the invention will typically be in the range of 0 to 15% of the total volume of the dry ingredients, where the dry ingredients of the composition are the reactive powders (examples of reactive powders: hydraulic cement only; blend of hydraulic cement and pozzolan; or blend of hydraulic cement, calcium sulfate alpha hemihydrate, pozzolan, and lime), ceramic microspheres, polymer microspheres, and alkali-resistant glass fibers. A typical aqueous mixture has a ratio of water-to-reactive powders from greater than 0.3/1 to 0.7/1.
As mentioned above, if desired the panel may have a single layer or multiple layers of SCP material. Typically, the panel is made by a process which applies multiple layers which, depending upon how the layers are applied and cured as well as whether the layers have the same or different compositions, may or may not in the final panel product retain distinct layers. FIG. 29 shows a multi-layer structure of a panel 101 having layers 102 , 104 , 106 and 108 . In the multi-layer structure the composition of the layers may be the same or different. The typical thickness of the layer(s) ranges between about 1/32 to 1.0 inches (about 0.75 to 25.4 mm). Where only one outer layer is used, it typically will be less than ⅜ of the total panel thickness.
Typical Configurations of Reinforced SCP Panels of the Present Invention
FIG. 1 is a top view of a first embodiment of a metal reinforced structural cementitious panel (SCP) panel 10 of the present invention employing strips 14 of reinforcing sheets attached to the SCP material 12 of the panel 10 . The strips 14 are implanted in cavities on the surface of the panel such that the upper surface of the strips 14 is flush with the uppermost surface of the SCP material 12 . The reinforcing strips 14 are typically metal, polymer or mesh having a thickness “A”. Typical metal reinforcing strips 14 have a thickness “A” of about 0.02 to about 0.07 inches (about 0.05 to about 0.2 cm) thick. The metal is typically steel or aluminum. For example, steel sheets about 25 to 14 gauge, e.g., 22 gauge. The metal can be replaced by one or more sheets of polymer, e.g., thermoplastic polymer or thermosetting polymer, or mesh, e.g. fiber glass mesh or carbon fiber mesh having a thickness “A” of about 1/32 to ¼ inch (about 0.08 to about 0.6 cm).
FIG. 2 is a cross-sectional view along view II-II of the panel 10 of FIG. 1 .
FIG. 3 is a top view of a second embodiment of a metal reinforced SCP panel 11 of the present invention employing strips 15 , 17 of reinforcing sheets embedded in the SCP material 13 of the panel 10 . The strips include strips 15 which wrap around opposed edges of the panel. In a second embodiment, the edges of the SCP panel are stiffened by placing metal along the SCP panel edges and bending the metal, e.g., ⅜ inch of metal edge, approximately 90 degrees to form a shallow tray to protect the edges of the SCP panel and add to the lateral fastener tear out along edges when the panel is loaded in shear.
FIG. 4 is a cross-sectional view along view IV-IV of the panel 11 of FIG. 3 .
FIG. 5 is a top view of a third embodiment of a reinforced SCP panel 20 of the present invention having reinforcement strips 24 which protrude from a surface of the SCP material 22 of the panel 20 .
FIG. 6 is a cross-sectional view along view VI-VI of the panel 20 of FIG. 5 .
FIG. 7 is a top view of a fourth embodiment of a reinforced SCP panel 30 of the present invention including reinforcing strips 34 which wrap around opposed sidewalls of the SCP material 32 of the panel 30 . Optionally, a reinforcing strip 36 is also attached to the SCP material 32 .
FIG. 8 is a cross-sectional view along view VIII-VIII of the panel 30 of FIG. 7 .
FIG. 9 is a perspective view of a fifth embodiment of a reinforced SCP panel 40 of the present invention including reinforcing mesh 44 which wraps around opposed walls of the SCP material 46 of the panel 40 .
FIG. 10 is a top view of a sixth embodiment of a reinforced SCP panel 50 of the present invention including separate reinforcing corner pieces 54 and optional reinforcing strips 56 attached to the SCP material 52 of the panel 50 .
FIG. 11 is a cross-sectional view along view XI-XI of the panel 50 of FIG. 10 .
FIG. 12 is a cross-sectional view along view XII-XII of the panel 50 of FIG. 10 .
FIG. 13 is a top view of a seventh embodiment of a reinforced SCP panel 60 of the present invention including a central reinforcing strip 68 and separate reinforcing corner pieces 64 . Optionally, the panel 60 is further provided with two reinforcing strips 66 which contact the corner pieces 64 .
FIG. 14 is a cross-sectional view along view XIV-XIV of the panel 60 of FIG. 13 .
FIG. 15 is a cross-sectional view along view XV-XV of the panel 60 of FIG. 13 .
FIG. 16 is a top view of a eighth embodiment of a reinforced SCP panel 70 of the present invention employing an one piece reinforced border 74 placed into a notched area along the perimeter of one of the surfaces of the SCP material 72 . The outer perimeter of the border 74 overlaps the outer perimeter of the surface of the SCP material 72 to which the border 74 is attached.
FIG. 17 is a cross-sectional view along view XVII-XVII of the panel 70 of FIG. 16 .
FIG. 18 is a top view of a ninth embodiment of a reinforced SCP panel 80 of the present invention which is the same as the embodiment of FIG. 16 , but for employing a multi-piece reinforced border on one of the surfaces of the SCP material 82 . The border including corner pieces 84 , longitudinal side pieces 86 and transverse side pieces 88 .
FIG. 19 is a top view of a tenth embodiment of a reinforced SCP panel 90 of the present invention employing a panel 94 , having perforations 96 , attached to SCP material 92 .
FIG. 20 is a cross-sectional view along view XX-XX of the panel 90 of FIG. 19 .
FIG. 21 is a perspective view of the panel 90 of FIG. 19 . FIG. 21 shows the panel 90 has a tongue 91 and a groove 93 . The other embodiments of the present invention also optionally have a tongue and groove on opposed sidewalls.
FIG. 22 is a perspective view of a portion of an eleventh embodiment of a reinforced SCP panel 95 of the present invention employing a panel 99 , with small perforations, attached to the SCP material 97 . Typical ranges for holes/perforations of FIGS. 19 and 22 are as follows:
Range of hole size: 1/32″ diameter to 12″ diameter
Range of Hole density per square foot: 0.5 to 20,000
Surface area of reinforcement coverage range: 5% to 90% (this is different than the 10-80% reinforcement coverage range for the other reinforcement members).
FIG. 23 is a top view of a portion of a twelfth embodiment of a reinforced SCP panel 130 of the present invention employing a crossed pair of reinforcing members 134 , 136 , attached to SCP material 132 . The crossed pair of reinforcing members 134 , 136 overlap where they cross.
FIG. 24 is a cross-sectional view along view XXIV-XXIV of the reinforced SCP panel 130 of FIG. 23 .
FIG. 25 is a top view of a portion of a thirteenth embodiment of a reinforced SCP panel 140 of the present invention employing three reinforcing members 144 , 146 , 148 attached to SCP material 142 to form a cross-shaped pattern.
FIG. 26 is a cross-sectional view along view XXVI-XXVI of the panel 140 of FIG. 25 .
FIG. 27 is a top view of a portion of a fourteenth embodiment of a reinforced SCP panel of the present invention a crossed pair of reinforcing members 154 , 155 attached to SCP material 152 to form a cross-shaped pattern and framed by a multi-piece reinforced border on one of the surfaces of the SCP material 152 . The border including corner pieces 153 , longitudinal side pieces 156 and transverse side pieces 151 .
FIG. 28 is a cross-sectional view along view XXVIII-XXVIII of the panel 150 of FIG. 27 .
FIG. 29 is a side view of a multi-layer SCP panel 101 of the present invention having layers 102 , 104 , 106 , 108 , with the reinforcement omitted for clarity.
Use of the Panels on Framing
FIG. 30 is a perspective view of a typical metal wall frame suitable for use with the reinforced SCP panels of the present invention. As shown in FIG. 30 , a frame 110 for supporting the walls of the foundation 2 includes a lower track 112 , a plurality of metal studs 120 , and an optional spacer member 140 . SCP panels 101 ( FIG. 29 ) may be secured in any known manner to the outer side, and if desired the inner side, of the metal wall frame 110 to close the wall and form the exterior surface or surfaces of the wall. U.S. Pat. No. 6,694,695 to Collins et al., incorporated herein by reference, more fully describes the arrangement of this metal wall frame.
The studs 120 are generally C-shaped. More particularly, the studs 120 have a web 122 and a pair of L-shaped flanges 124 perpendicular to the web 122 . There are also one or more openings 126 in the web 122 . The openings 126 permit electrical conduit and plumbing to be run within the stud wall. The metal studs 120 are secured at one end 121 to lower track 112 by conventional fasteners 123 such as, for example, screws, rivets, etc. The lower track 112 is also C-shaped with a central web portion 114 and two legs 116 protruding from web 114 . In the present foundation system, the web 114 of the bottom track 112 is typically affixed to a floor (not shown) with conventional fasteners such as screws, bolts, rivets, etc.
An optional V-shaped stud spacer member 140 having a crease 149 is inserted through the aligned openings 126 provided through the webs 122 of the respective studs 120 such that notches 142 in the stud spacer member 140 engage the stud openings 126 of the web 122 of respective studs 120 .
FIG. 35 is a perspective view of a typical metal floor frame 460 suitable for use with the reinforced SCP panels of the present invention. The metal frame 460 has C-joist framing 450 supported on a header or longitudinal rim track 452 . In practice, the reinforced SCP panels may be mechanically or adhesively attached to the C-joists 450 or be not attached to the C-joists (i.e., be floating).
The joists were attached to the rim track 452 using screws into the side of the joist through a pre-bent tab and screws through the top of rim track into the joist 450 , at each end. Steel angles 451 were also fastened with screws to the respective joist 450 and to the rim track 452 . KATZ blocking 458 was fastened to the bottom of the joists 450 across the center line of the floor. The blocking 458 was attached using a screw through the end of each Katz blocking member 458 . In particular, the Katz blocking 458 is located between transverse joints 450 by being positioned staggered on either side of the midpoint and attached by screws. Additional horizontal blocking may be added to the rim track 452 on the load side to strengthen the rim track 452 for point loading purposes. Namely, blocking 457 for load support is provided along the longitudinal rim track between a number of transverse joists 450 . 20 inch long blocking 459 is fixed between each transverse end joist and the respective penultimate transverse end 452 joist generally along the longitudinal axis of the frame with screws. Typically a reinforced SCP panel could be attached to the frame by screws or adhesive. Afterwards, at the butt-joints and tongue and groove locations of the panels, an adhesive, for example ENERFOAM SF polyurethane foam adhesive manufactured by Flexible Products Company of Canada, Inc., could be applied in the joint.
U.S. Pat. No. 6,691,478 B2 to Daudet et al. discloses another example of a suitable metal flooring system.
FIG. 36 is a fragmentary schematic vertical section of a single-layer SCP panel 462 supported on metal frame 460 of FIG. 35 in a system of the present invention. If desired a fastener (not shown) may attach the SCP panel to a C-joist of the metal frame 460 . In practice the floor may be mechanically or adhesively attached to the C-joist or be not attached to the C-joist (i.e., be floating).
The frames may be wood or any metal, e.g., steel or galvanized steel, framing systems suitable for supporting flooring. Typical metal frames include C-joists having openings therein for passing plumbing and electrical lines there through and headers for supporting the C-joists about the floor perimeter. Preferably the frames are metal to result in a non-combustible system.
FIG. 37 is a perspective view of SCP panels 416 of FIG. 36 supported on a corrugated sheet 403 in the non-combustible flooring system of the present invention.
In FIG. 38 the numeral 401 generally designates a composite flooring deck assembly comprising a corrugated sheet 403 supported from below by a joist (not shown, but which could for example be a C-joist or I-beam beam or any other suitable joist) and secured from above by mechanical fasteners 405 to a diaphragm 407 of SCP panels 416 .
Corrugated sheet 403 typically has flat portions 408 and 410 of substantially equal length joined by connector portions 412 providing straight, parallel, regular, and equally curved ridges and hollows. This configuration has a substantially equal distribution of surface area of the corrugated sheet above and below a neutral axis 414 (as seen in FIG. 38 ). Optionally the panels 416 have a tongue 418 and groove 420 formed on opposite edges thereof to provide for continuous interlocking of flooring substrate panels 416 to minimize joint movement under moving and concentrated loads.
The embodiment of FIG. 37 involves a design using a system of corrugated steel decking, designed using steel properties provided by the Steel Deck Institute (SDI) applied over steel joists and girders. A ceiling (not shown), such as gypsum drywall mounted on DIETRICH RC DELUXE channels may be attached to the bottoms of the joists or ceiling tiles and grid may be hung from the joists. An alternate is for the bottom surfaces of the steel to be covered with spray fiber or fireproofing materials. The steel joists which support the steel decking are any which can support the system. Typical steel joists may include those outlined by the SSMA (Steel Stud Manufacturer's Association) for use in corrugated steel deck systems, or proprietary systems, such as those sold by Dietrich as TRADE READY Brand joists. Joist spacing of 24 inches (61 cm) is common. However, spans between joists may be greater or less than this. C-joists and open web joists are typical.
In the particular embodiment of the invention illustrated in FIG. 37 , SCP panels 416 have sufficient strength to create a structural bridge over the wide rib openings 422 . FIG. 38 shows the SCP panels 416 attached to the corrugated sheet 403 by screws 405 .
As illustrated in FIG. 39 , for a roof deck, spaced screws 405 , having screw heads 442 are oriented to form a series of generally triangular shaped horizontally disposed trusses (for example, truss T h shown as the horizontal line between two of the screws 405 ) and a series of vertically disposed trusses T v throughout the length and width of spans between spaced joists P (such as that shown in the embodiment of FIG. 40 ) to increase the resistance to horizontal and vertical planar deflection of the roof deck. SCP panel 416 is described in more detail below. In the form of the invention illustrated in FIG. 39 the diaphragm 407 comprises an SCP panel 416 positioned over a sheet of insulation material 430 .
FIG. 40 is a cross-sectional view of the SCP panel of FIG. 36 supported on a corrugated sheet of a roofing system wherein the SCP panel 416 is secured over a sheet of insulation material 430 in the non-combustible building system of the present invention. In the form of the invention of FIG. 40 the diaphragm 407 is secured to upper ridge portions 208 of the corrugated sheet 403 by threaded screws 405 having enlarged heads 442 .
The form of the system illustrated in FIG. 40 is similar to that of FIG. 39 except that a layer or sheet 430 of thermal insulation material is positioned over the SCP panels 416 to form the diaphragm 407 . Sheet 430 of insulation material typically comprises incombustible foamed polystyrene or other suitable insulation material. For example, other insulation material such as polyurethane, fiberglass, cork and the like may be employed in combination with or in lieu of the polystyrene.
Formulation of SCP Panels
The components used to make the shear resistant panels of the invention include hydraulic cement, calcium sulfate alpha hemihydrate, an active pozzolan such as silica fume, lime, ceramic microspheres, alkali-resistant glass fibers, superplasticizer (e.g., sodium salt of polynapthalene sulfonate), and water. Typically, both hydraulic cement and calcium sulfate alpha hemihydrate are present. Long term durability of the composite is compromised if calcium sulfate alpha hemihydrate is not present along with silica fume. Water/moisture durability is compromised when Portland cement is not present. Small amounts of accelerators and/or retarders may be added to the composition to control the setting characteristics of the green (i.e., uncured) material. Typical non-limiting additives include accelerators for hydraulic cement such as calcium chloride, accelerators for calcium sulfate alpha hemihydrate such as gypsum, retarders such as DTPA (diethylene triamine pentacetic acid), tartaric acid or an alkali salt of tartaric acid (e.g., potassium tartrate), shrinkage reducing agents such as glycols, and entrained air.
Panels of the invention will include a continuous phase in which alkali-resistant glass fibers and light weight filler, e.g., microspheres, are uniformly distributed. The continuous phase results from the curing of an aqueous mixture of the reactive powders, i.e., blend of hydraulic cement, calcium sulfate alpha hemihydrate, pozzolan, and lime), preferably including superplasticizer and/or other additives.
Typical weight proportions of embodiments of the reactive powders (inorganic binder), e.g., hydraulic cement, calcium sulfate alpha hemihydrate, pozzolan and lime, in the invention, based on dry weight of the reactive powders, are shown in TABLE 1. TABLE 1A lists typical ranges of reactive powders, lightweight filler, and glass fibers in compositions of the present invention.
TABLE 1
Weight Percent
Typical Weight
Reactive Powder
(%)
Percent (%)
Hydraulic Cement
20-55
25-40
Calcium Sulfate Alpha Hemihydrate
35-75
45-65
Pozzolan
5-25
10-15
Lime
up to 3.5 or
0.75-1.25
from 0.2 to 3.5
TABLE 1A
Typical Weight
SCP Composition (dry basis)
Weight Percent (%)
Percent (%)
Reactive Powder
35-70
35-68
Lightweight Filler
20-50
23-49
Glass Fibers
5-20
5-17
Lime is not required in all formulations of the invention, but it has been found that adding lime provides superior panels and it usually will be added in amounts greater than about 0.2 wt. %. Thus, in most cases, the amount of lime in the reactive powders will be about 0.2 to 3.5 wt. %.
In the first embodiment of an SCP material for use in the invention, the dry ingredients of the composition will be the reactive powders (i.e., blend of hydraulic cement, calcium sulfate alpha hemihydrate, pozzolan, and lime), ceramic microspheres and alkali-resistant glass fibers, and the wet ingredients of the composition will be water and superplasticizer. The dry ingredients and the wet ingredients are combined to produce the panel of the invention. The ceramic microspheres are uniformly distributed in the matrix throughout the full thickness of the panel. Of the total weight of dry ingredients, the panel of the invention is formed from about 49 to 56 wt. % reactive powders, 35 to 42 wt. % ceramic microspheres and 7 to 12 wt. % alkali-resistant glass fibers. In a broad range, the panel of the invention is formed from 35 to 58 wt. % reactive powders, 34 to 49 wt. % lightweight filler, e.g., ceramic microspheres, and 6 to 17 wt. % alkali-resistant glass fibers of the total dry ingredients. The amounts of water and superplasticizer added to the dry ingredients will be sufficient to provide the desired slurry fluidity needed to satisfy processing considerations for any particular manufacturing process. The typical addition rates for water range between 35 to 60% of the weight of reactive powders and those for superplasticizer range between 1 to 8% of the weight of reactive powders.
The glass fibers are monofilaments having a diameter of about 5 to 25 microns (micrometers), preferably about 10 to 15 microns (micrometers). The monofilaments typically are combined in 100 filament strands, which may be bundled into rovings of about 50 strands. The length of the glass fibers will typically be about 0.25 to 1 or 2 inches (6.3 to 25 or 50 mm) or about 1 to 2 inches (25 to 50 mm) and broadly about 0.25 to 3 inches (6.3 to 76 mm). The fibers have random orientation, providing isotropic mechanical behavior in the plane of the panel.
A second embodiment of an SCP material suitable for use in the invention contains a blend of ceramic and glass microspheres uniformly distributed throughout the full thickness of the panel. Accordingly, the dry ingredients of the composition will be the reactive powders (hydraulic cement, calcium sulfate alpha hemihydrate, pozzolan, and lime), ceramic microspheres, glass microspheres, and alkali-resistant glass fibers, and the wet ingredients of the composition will be water and superplasticizer. The dry ingredients and the wet ingredients will be combined to produce the panel of the invention. The volume fraction of the glass microspheres in the panel will typically be in the range of 7 to 15% of the total volume of dry ingredients. Of the total weight of dry ingredients, the panel of the invention is formed from about 54 to 65 wt. % reactive powders, 25 to 35 wt. % ceramic microspheres, 0.5 to 0.8 wt. % glass microspheres, and 6 to 10 wt. % alkali-resistant glass fibers. In the broad range, the panel of the invention is formed from 42 to 68 wt. % reactive powders, 23 to 43 wt. % lightweight fillers, e.g., ceramic microspheres, 0.2 to 1.0 wt. % glass microspheres, and 5 to 15 wt. % alkali-resistant glass fibers, based on the total dry ingredients. The amounts of water and superplasticizer added to the dry ingredients will be adjusted to provide the desired slurry fluidity needed to satisfy the processing considerations for any particular manufacturing process. The typical addition rates for water range between 35 to 70% of the weight of reactive powders, but could be greater than 60% up to 70% (weight ratio of water to reactive powder of 0.6/1 to 0.7/1), preferably 65% to 75%, when it is desired to use the ratio of water-to-reactive powder to reduce panel density and improve cutability. The amount of superplasticizer will range between 1 to 8% of the weight of reactive powders. The glass fibers are monofilaments having a diameter of about 5 to 25 microns (micrometers), preferably about 10 to 15 microns (micrometers). They typically are bundled into strands and rovings as discussed above. The length of the glass fibers typically is about 1 to 2 inches (25 to 50 mm) and broadly about 0.25 to 3 inches (6.3 to 76 mm). The fibers will have random orientation providing isotropic mechanical behavior in the plane of the panel.
A third embodiment of SCP material suitable for use in the invention, contains a multi-layer structure in the panel created where the outer layer(s) have improved nailability (fastening ability)/cutability. This is achieved by increasing the water-to-cement ratio in the outer layer(s), and/or changing the amount of filler, and/or adding an amount of polymer microspheres sufficiently small such that the panel remains noncombustible. The core of the panel will typically contain ceramic microspheres uniformly distributed throughout the layer thickness or alternatively, a blend of one or more of ceramic microspheres, glass microspheres and fly ash cenospheres.
The dry ingredients of the core layer of this third embodiment are the reactive powders (typically hydraulic cement, calcium sulfate alpha hemihydrate, pozzolan, and lime), lightweight filler particles (typically microspheres such as ceramic microspheres alone or one or more of ceramic microspheres, glass microspheres and fly ash cenospheres), and alkali-resistant glass fibers, and the wet ingredients of the core layer are water and superplasticizer. The dry ingredients and the wet ingredients will be combined to produce the core layer of the panel of the invention. Of the total weight of dry ingredients, the core of the panel of the invention preferably is formed from about 49 to 56 wt. % reactive powders, 35 to 42 wt. % hollow ceramic microspheres and 7 to 12 wt. % alkali-resistant glass fibers, or alternatively, about 54 to 65 wt. % reactive powders, 25 to 35 wt. % ceramic microspheres, 0.5 to 0.8 wt. % glass microspheres or fly ash cenospheres, and 6 to 10 wt. % alkali-resistant glass fibers. In the broad range, the core layer of the panel of this embodiment of the present invention is typically formed by about 35 to 58 wt. % reactive powders, 34 to 49 wt. % lightweight fillers, e.g., ceramic microspheres, and 6 to 17 wt. % alkali-resistant glass fibers, based on the total dry ingredients, or alternatively, about 42 to 68 wt. % of reactive powders, 23 to 43 wt. % ceramic microspheres, up to 1.0 wt. %, preferably 0.2 to 1.0 wt. %, other lightweight filler, e.g., glass microspheres or fly ash cenospheres, and 5 to 15 wt. % alkali-resistant glass fibers. The amounts of water and superplasticizer added to the dry ingredients will be adjusted to provide the desired slurry fluidity needed to satisfy the processing considerations for any particular manufacturing process. The typical addition rates for water will range between 35 to 70% of the weight of reactive powders but will be greater than 60% up to 70% when it is desired to use the ratio of water-to-reactive powders to reduce panel density and improve nailability and those for superplasticizer will range between 1 to 8% of the weight of reactive powders. When the ratio of water-to-reactive powder is adjusted, the slurry composition will be adjusted to provide the panel of the invention with the desired properties.
There is generally an absence of polymer microspheres and an absence of polymer fibers that would cause the SCP panel to become combustible.
The dry ingredients of the outer layer(s) of this third embodiment will be the reactive powders (typically hydraulic cement, calcium sulfate alpha hemihydrate, pozzolan, and lime), lightweight filler particles (typically microspheres such as ceramic microspheres alone or one or more of ceramic microspheres, glass microspheres and fly ash cenospheres), and alkali-resistant glass fibers, and the wet ingredients of the outer layer(s) will be water and superplasticizer. The dry ingredients and the wet ingredients are combined to produce the outer layers of the panel of the invention. In the outer layer(s) of the panel of this embodiment of the present invention, the amount of water is selected to furnish good fastening and cutting ability to the panel. Of the total weight of dry ingredients, the outer layer(s) of the panel of the invention preferably are formed from about 54 to 65 wt. % reactive powders, 25 to 35 wt. % ceramic microspheres, 0 to 0.8 wt. % glass microspheres, and 6 to 10 wt. % alkali-resistant glass fibers. In the broad range, the outer layers of the panel of the invention are formed from about 42 to 68 wt. % reactive powders, 23 to 43 wt. % ceramic microspheres, up to 1.0 wt. % glass microspheres (and/or fly ash cenospheres), and 5 to 15 wt. % alkali-resistant glass fibers, based on the total dry ingredients. The amounts of water and superplasticizer added to the dry ingredients are adjusted to provide the desired slurry fluidity needed to satisfy the processing considerations for any particular manufacturing process. The typical addition rates for water range between 35 to 70% of the weight of reactive powders and particularly greater than 60% up to 70% when the ratio of water-to-reactive powders is adjusted to reduce panel density and improve nailability, and typical addition rates for superplasticizer will range between 1 to 8% of the weight of reactive powders. The preferable thickness of the outer layer(s) ranges between 1/32 to 4/32 inches (0.8 to 3.2 mm) and the thickness of the outer layer when only one is used will be less than ⅜ of the total thickness of the panel.
In both the core and outer layer(s) of this embodiment of the present invention, the glass fibers are monofilaments having a diameter of about 5 to 25 microns (micrometers), preferably 10 to 15 microns (micrometers). The monofilaments typically are bundled into strands and rovings as discussed above. The length typically is about 1 to 2 inches (25 to 50 mm) and broadly about 0.25 to 3 inches (6.3 to 76 mm). The fiber orientation will be random, providing isotropic mechanical behavior in the plane of the panel.
A fourth embodiment of SCP material for use in the present invention provides a multi-layer panel having a density of 65 to 90 pounds per cubic foot and capable of resisting shear loads when fastened to framing and comprising a core layer of a continuous phase resulting from the curing of an aqueous mixture, a continuous phase resulting from the curing of an aqueous mixture comprising, on a dry basis, 35 to 70 weight % reactive powder, 20 to 50 weight percent lightweight filler, and 5 to 20 weight % glass fibers, the continuous phase being reinforced with glass fibers and containing the lightweight filler particles, the lightweight filler particles having a particle specific gravity of from 0.02 to 1.00 and an average particle size of about 10 to 500 microns (micrometers); and at least one outer layer of respectively another continuous phase resulting from the curing of an aqueous mixture comprising, on a dry basis, 35 to 70 weight % reactive powder, 20 to 50 weight percent lightweight filler, and 5 to 20 weight % glass fibers, the continuous phase being reinforced with glass fibers and containing the lightweight filler particles, the lightweight filler particles having a particle specific gravity of from 0.02 to 1.00 and an average particle size of about 10 to 500 microns (micrometers) on each opposed side of the inner layer, wherein the at least one outer layer has a higher percentage of glass fibers than the inner layer.
Making a Panel of the Invention
The reactive powders, e.g., blend of hydraulic cement, calcium sulfate alpha hemihydrate, pozzolan, and lime), and lightweight filler, e.g., microspheres, are blended in the dry state in a suitable mixer.
Then, water, a superplasticizer (e.g., the sodium salt of polynapthalene sulfonate), and the pozzolan (e.g., silica fume or metakaolin) are mixed in another mixer for 1 to 5 minutes. If desired, a retarder (e.g., potassium tartrate) is added at this stage to control the setting characteristics of the slurry. The dry ingredients are added to the mixer containing the wet ingredients and mixed for 2 to 10 minutes to form smooth homogeneous slurry.
The slurry is then combined with glass fibers, in any of several ways, with the objective of obtaining a uniform slurry mixture. The cementitious panels are then formed by pouring the slurry containing fibers into an appropriate mold of desired shape and size. If necessary, vibration is provided to the mold to obtain good compaction of material in the mold. The panel is given required surface finishing characteristics using an appropriate screed bar or trowel. The panel may then be embossed to provide indentations and the reinforcement members are inserted into the indentations and attached to the panel. If desired, rather than placing the reinforcement members into indentations, they may be placed on the non-indented surface to protrude from the panel.
One of a number of methods to make multi-layer SCP panels is as follows. The reactive powders, e.g., blend of hydraulic cement, calcium sulfate alpha hemihydrate, pozzolan, and lime), and lightweight filler, e.g., microspheres, are blended in the dry state in a suitable mixer. Then, water, a superplasticizer (e.g., the sodium salt of polynapthalene sulfonate), and the pozzolan (e.g., silica fume or metakaolin) are mixed in another mixer for 1 to 5 minutes. If desired, a retarder (e.g., potassium tartrate) is added at this stage to control the setting characteristics of the slurry. The dry ingredients are added to the mixer containing the wet ingredients and mixed for 2 to 10 minutes to form a smooth homogeneous slurry.
The slurry may be combined with the glass fibers in several ways, with the objective of obtaining a uniform mixture. The glass fibers typically will be in the form of rovings that are chopped into short lengths. In a preferred embodiment, the slurry and the chopped glass fibers are concurrently sprayed into a panel mold. Preferably, spraying is done in a number of passes to produce thin layers, preferably up to about 0.25 inches (6.3 mm) thick, which are built up into a uniform panel having no particular pattern and with a thickness of ¼ to 1 inch (6.3 to 25.4 mm). For example, in one application, a 3×5 ft (0.91×1.52 m) panel was made with six passes of the spray in the length and width directions. As each layer is deposited, a roller may be used to assure that the slurry and the glass fibers achieve intimate contact. The layers may be leveled with a screed bar or other suitable means after the rolling step. Typically, compressed air will be used to atomize the slurry. As it emerges from the spray nozzle, the slurry mixes with glass fibers that have been cut from a roving by a chopper mechanism mounted on the spray gun. The uniform mixture of slurry and glass fibers is deposited in the panel mold as described above.
If desired the outer surface layers of the panel may contain polymer spheres, or be otherwise constituted, in order that the fasteners used to attach the panel to framing can be driven easily. The preferable thickness of such layers will be about 1/32 inches to 4/32 inches (0.8 to 3.2 mm). The same procedure described above by which the core of the panel is made may be used to apply the outer layers of the panel.
Other methods of depositing a mixture of the slurry and glass fibers will occur to those familiar with the panel-making art. For example, rather than using a batch process to make each panel, a continuous sheet may be prepared in a similar manner, which after the material has sufficiently set, can be cut into panels of the desired size. The percentage of fibers relative to the volume of slurry typically constitutes approximately in the range of 0.5% to 3%, for example 1.5%. Typical panels have a thickness of about ¼ to 1½ inches (6.3 to 38.1 mm).
The SCP panels are typically embossed with a pattern sufficiently deep such that the reinforcement when inserted into the pattern has an outer surface flush with the outer surface of the panel. Although, if desired, the embossing may be omitted such that the reinforcement upper surface will protrude from the surface of the SCP panel.
The reinforcement members are preferably at least temporarily affixed to the SCP panel by an adhesive applied to one of the mating major surfaces. Other attachment means of affixing reinforcement members to SCP panel, such as double sided tape, may be employed also. The adhesive may be epoxy or glue, and may be applied by various means such as brushing or spraying, for example. Further, the adhesive may be applied to a portion or portions of one or both of the major surfaces. However, adhesive is preferably spread over the extent of one of the major surfaces of one of either wallboard panel or reinforcement piece and is a water soluble latex based glue. The amount of adhesive applied to adhere the SCP panel and reinforcement piece together is an amount at least sufficient to hold these two members together such that the composite wallboard structure can be handled and constructed into a building wall structure. Thus, the adhesive applied between the SCP panel and reinforcement piece is of sufficient quantity to hold these two members together while the composite structure is being handled, shipped and attached to building wall framing studs or floor framing joists, in typical building construction processes.
The reinforced SCP panel could be made by automated processes. For example, an SCP panel could be manufactured and provided by automated machinery well known in the industry. The SCP panel could continue its processing by spraying one of its surfaces with an adhesive utilizing a spraying device stationed over SCP panel. A reinforcement piece such as a metal strip can thereafter be laid on the adhesive by a robotics mechanism.
Another method of making panels of the present invention is by using the process steps disclosed in U.S. patent application Ser. No. 10/666,294 incorporated herein by reference. U.S. patent application Ser. No. 10/666,294, incorporated herein by reference, discloses after one of an initial deposition of loosely distributed, chopped fibers or a layer of slurry upon a moving web, fibers are deposited upon the slurry layer. An embedment device compacts the recently deposited fibers into the slurry, after which additional layers of slurry, then chopped fibers are added, followed by more embedment. The process is repeated for each layer of the board, as desired. Then the board is typically embossed to have a pattern of indentations and the reinforcement members are inserted into the indentations and attached to the board.
More specifically, U.S. patent application Ser. No. 10/666,294 discloses a multi-layer process for producing structural cementitious panels, including: (a.) providing a moving web; (b.) one of depositing a first layer of loose fibers and (c.) depositing a layer of settable slurry upon the web; (d.) depositing a second layer of loose fibers upon the slurry; (e.) embedding the second layer of fibers into the slurry; and (f.) repeating the slurry deposition of step (c.) through step (d.) until the desired number of layers of settable fiber-enhanced slurry in the panel is obtained.
FIG. 31 is a diagrammatic elevational view of an apparatus which is suitable for performing the process of U.S. patent application Ser. No. 10/666,294, but for adding embossing capability to the forming device 394 and adding a reinforcement member attaching station 400 .
Referring now to FIG. 31 , a structural panel production line is diagrammatically shown and is generally designated 310 . The production line 310 includes a support frame or forming table 312 having a plurality of legs 313 or other supports. Included on the support frame 312 is a moving carrier 314 , such as an endless rubber-like conveyor belt with a smooth, water-impervious surface, however porous surfaces are contemplated. As is well known in the art, the support frame 312 may be made of at least one table-like segment, which may include designated legs 313 . The support frame 312 also includes a main drive roll 316 at a distal end 318 of the frame, and an idler roll 320 at a proximal end 322 of the frame. Also, at least one belt tracking and/or tensioning device 324 is preferably provided for maintaining a desired tension and positioning of the carrier 314 upon the rolls 316 , 320 .
Also, in the preferred embodiment, a web 326 of Kraft paper, release paper, and/or other webs of support material designed for supporting slurry prior to setting, as is well known in the art, may be provided and laid upon the carrier 314 to protect it and/or keep it clean. However, it is also contemplated that the panels produced by the present line 310 are formed directly upon the carrier 314 . In the latter situation, at least one belt washing unit 328 is provided. The carrier 314 is moved along the support frame 312 by a combination of motors, pulleys, belts or chains which drive the main drive roll 316 as is known in the art. It is contemplated that the speed of the carrier 314 may vary to suit the application.
In the apparatus of FIG. 31 , structural cementitious panel production is initiated by one of depositing a layer of loose, chopped fibers 330 or a layer of slurry upon the web 326 . An advantage of depositing the fibers 330 before the first deposition of slurry is that fibers will be embedded near the outer surface of the resulting panel. A variety of fiber depositing and chopping devices are contemplated by the present line 310 , however the preferred system employs at least one rack 331 holding several spools 332 of fiberglass cord, from each of which a cord 334 of fiber is fed to a chopping station or apparatus, also referred to as a chopper 336 .
The chopper 336 includes a rotating bladed roll 338 from which project radially extending blades 340 extending transversely across the width of the carrier 314 , and which is disposed in close, contacting, rotating relationship with an anvil roll 342 . In the preferred embodiment, the bladed roll 338 and the anvil roll 342 are disposed in relatively close relationship such that the rotation of the bladed roll 338 also rotates the anvil roll 342 , however the reverse is also contemplated. Also, the anvil roll 342 is preferably covered with a resilient support material against which the blades 340 chop the cords 334 into segments. The spacing of the blades 340 on the roll 338 determines the length of the chopped fibers. As is seen in FIG. 31 , the chopper 336 is disposed above the carrier 314 near the proximal end 322 to maximize the productive use of the length of the production line 310 . As the fiber cords 334 are chopped, the fibers 330 fall loosely upon the carrier web 326 .
Next, a slurry feed station, or a slurry feeder 344 receives a supply of slurry 346 from a remote mixing location 347 such as a hopper, bin or the like. It is also contemplated that the process may begin with the initial deposition of slurry upon the carrier 314 . The slurry is preferably comprised of varying amounts of Portland cement, gypsum, aggregate, water, accelerators, plasticizers, foaming agents, fillers and/or other ingredients, and described above and in the patents listed above which have been incorporated by reference for producing SCP panels. The relative amounts of these ingredients, including the elimination of some of the above or the addition of others, may vary to suit the use.
While various configurations of slurry feeders 344 are contemplated which evenly deposit a thin layer of slurry 346 upon the moving carrier 314 , the preferred slurry feeder 344 includes a main metering roll 348 disposed transversely to the direction of travel of the carrier 314 . A companion or back up roll 350 is disposed in close parallel, rotational relationship to the metering roll 348 to form a nip 352 there between. A pair of sidewalls 354 , preferably of non-stick material such as Teflon® brand material or the like, prevents slurry 346 poured into the nip 352 from escaping out the sides of the feeder 344 .
The feeder 344 deposits an even, relatively thin layer of the slurry 346 upon the moving carrier 314 or the carrier web 326 . Suitable layer thicknesses range from about 0.05 inch to 0.20 inch. However, with four layers preferred in the preferred structural panel produced by the present process, and a suitable building panel being approximately 0.5 inch, an especially preferred slurry layer thickness is approximately 0.125 inch.
Referring now to FIGS. 31 and 32 , to achieve a slurry layer thickness as described above, several features are provided to the slurry feeder 344 . First, to ensure a uniform disposition of the slurry 346 across the entire web 326 , the slurry is delivered to the feeder 344 through a hose 356 located in a laterally reciprocating, cable driven, fluid powered dispenser 358 of the type well known in the art. Slurry flowing from the hose 356 is thus poured into the feeder 344 in a laterally reciprocating motion to fill a reservoir 359 defined by the rolls 348 , 350 and the sidewalls 354 . Rotation of the metering roll 348 thus draws a layer of the slurry 346 from the reservoir.
Next, a thickness monitoring or thickness control roll 360 is disposed slightly above and/or slightly downstream of a vertical centerline of the main metering roll 348 to regulate the thickness of the slurry 346 drawn from the feeder reservoir 357 upon an outer surface 362 of the main metering roll 348 . Also, the thickness control roll 360 allows handling of slurries with different and constantly changing viscosities. The main metering roll 348 is driven in the same direction of travel “T” as the direction of movement of the carrier 314 and the carrier web 326 , and the main metering roll 348 , the backup roll 350 and the thickness monitoring roll 360 are all rotatably driven in the same direction, which minimizes the opportunities for premature setting of slurry on the respective moving outer surfaces. As the slurry 346 on the outer surface 362 moves toward the carrier web 326 , a transverse stripping wire 364 located between the main metering roll 348 and the carrier web 326 ensures that the slurry 346 is completely deposited upon the carrier web and does not proceed back up toward the nip 352 and the feeder reservoir 359 . The stripping wire 364 also helps keep the main metering roll 348 free of prematurely setting slurry and maintains a relatively uniform curtain of slurry.
A second chopper station or apparatus 366 , preferably identical to the chopper 336 , is disposed downstream of the feeder 344 to deposit a second layer of fibers 368 upon the slurry 346 . In the preferred embodiment, the chopper apparatus 366 is fed cords 334 from the same rack 331 that feeds the chopper 336 . However, it is contemplated that separate racks 331 could be supplied to each individual chopper, depending on the application.
Referring now to FIGS. 31 and 33 , next, an embedment device, generally designated 370 is disposed in operational relationship to the slurry 346 and the moving carrier 314 of the production line 310 to embed the fibers 368 into the slurry 346 . While a variety of embedment devices are contemplated, including, but not limited to vibrators, sheep's foot rollers and the like, in the preferred embodiment, the embedment device 370 includes at least a pair of generally parallel shafts 372 mounted transversely to the direction of travel “T” of the carrier web 326 on the frame 312 . Each shaft 372 is provided with a plurality of relatively large diameter disks 374 which are axially separated from each other on the shaft by small diameter disks 376 .
During SCP panel production, the shafts 372 and the disks 374 , 376 rotate together about the longitudinal axis of the shaft. As is well known in the art, either one or both of the shafts 372 may be powered, and if only one is powered, the other may be driven by belts, chains, gear drives or other known power transmission technologies to maintain a corresponding direction and speed to the driving roll. The respective disks 374 , 376 of the adjacent, preferably parallel shafts 372 are intermeshed with each other for creating a “kneading” or “massaging” action in the slurry, which embeds the fibers 368 previously deposited thereon. In addition, the close, intermeshed and rotating relationship of the disks 372 , 374 prevents the buildup of slurry 346 on the disks, and in effect creates a “self-cleaning” action which significantly reduces production line downtime due to premature setting of clumps of slurry.
The intermeshed relationship of the disks 374 , 376 on the shafts 372 includes a closely adjacent disposition of opposing peripheries of the small diameter spacer disks 376 and the relatively large diameter main disks 374 , which also facilitates the self-cleaning action. As the disks 374 , 376 rotate relative to each other in close proximity (but preferably in the same direction), it is difficult for particles of slurry to become caught in the apparatus and prematurely set. By providing two sets of disks 374 which are laterally offset relative to each other, the slurry 346 is subjected to multiple acts of disruption, creating a “kneading” action which further embeds the fibers 368 in the slurry 346 .
Once the fibers 368 have been embedded, or in other words, as the moving carrier web 326 passes the embedment device 370 , a first layer 377 of the SCP panel is complete. In the preferred embodiment, the height or thickness of the first layer 377 is in the approximate range of 0.05-0.20 inches. This range has been found to provide the desired strength and rigidity when combined with like layers in a SCP panel. However, other thicknesses are contemplated depending on the application.
To build a structural cementitious panel of desired thickness, additional layers are needed. To that end, a second slurry feeder 378 , which is substantially identical to the feeder 344 , is provided in operational relationship to the moving carrier 314 , and is disposed for deposition of an additional layer 380 of the slurry 346 upon the existing layer 377 .
Next, an additional chopper 382 , substantially identical to the choppers 336 and 366 , is provided in operational relationship to the frame 312 to deposit a third layer of fibers 384 provided from a rack (not shown) constructed and disposed relative to the frame 312 in similar fashion to the rack 331 . The fibers 384 are deposited upon the slurry layer 380 and are embedded using a second embedment device 386 . Similar in construction and arrangement to the embedment device 370 , the second embedment device 386 is mounted slightly higher relative to the moving carrier web 314 so that the first layer 377 is not disturbed. In this manner, the second layer 380 of slurry and embedded fibers is created.
Referring now to FIG. 31 , with each successive layer of settable slurry and fibers, an additional slurry feeder station 344 , 378 , 402 followed by a fiber chopper 336 , 366 , 382 , 404 and an embedment device 370 , 386 , 406 is provided on the production line 310 . In the preferred embodiment, four total layers (see for example, the panel 101 of FIG. 29 ) are provided to form the SCP panel. Upon the disposition of the four layers of fiber-embedded settable slurry as described above, a forming device 394 is preferably provided to the frame 312 to shape an upper surface 396 of the panel. Such forming devices 394 are known in the settable slurry/board production art, and typically are spring-loaded or vibrating plates which conform the height and shape of the multi-layered panel to suit the desired dimensional characteristics.
The panel which is made has multiple layers (see for example layers 22 , 24 , 26 , 28 of panel 101 of FIG. 29 ) which upon setting form an integral, fiber-reinforced mass. Provided that the presence and placement of fibers in each layer are controlled by and maintained within certain desired parameters as is disclosed and described below, it will be virtually impossible to delaminate the panel.
At this point, the layers of slurry have begun to set, and the respective panels are separated from each other by a cutting device 398 , which in the preferred embodiment is a water jet cutter. Other cutting devices, including moving blades, are considered suitable for this operation, provided that they can create suitably sharp edges in the present panel composition. The cutting device 398 is disposed relative to the line 310 and the frame 312 so that panels are produced having a desired length, which may be different from the representation shown in FIG. 31 . Since the speed of the carrier web 314 is relatively slow, the cutting device 398 may be mounted to cut perpendicularly to the direction of travel of the web 314 . With faster production speeds, such cutting devices are known to be mounted to the production line 310 on an angle to the direction of web travel. Upon cutting, the separated panels 321 are stacked for further handling, packaging, storage and/or shipment as is well known in the art.
Then the reinforcement members are inserted into the pattern downstream of the forming device 394 and adhered with glue or other means to the SCP panel in an insertion and attaching station 400 . If desired, the forming device 394 embosses the SCP panel to make indentations in the SCP panels and the reinforcement members are placed into the indentations in the insertion and attaching station 400 .
In quantitative terms, the influence of the number of fiber and slurry layers, the volume fraction of fibers in the panel, and the thickness of each slurry layer, and fiber strand diameter on fiber embedment efficiency has been investigated. In the analysis, the following parameters were identified:
v T =Total composite volume
v s =Total panel slurry volume
v f =Total panel fiber volume
v f,l =Total fiber volume/layer
v T,l =Total composite volume/layer
v s,l =Total slurry volume/layer
N l =Total number of slurry layers; Total number of fiber layers
V f =Total panel fiber volume fraction
d f =Equivalent diameter of individual fiber strand
l f =Length of individual fiber strand
t=Panel thickness
t l =Total thickness of individual layer including slurry and fibers
t s,l =Thickness of individual slurry layer
n f,l , n f1,l , n f2,l =Total number of fibers in a fiber layer
s f,l P , s f,l P , s f2,l P =Total projected surface area of fibers contained in a fiber layer
S f,l P , S f1,l P , S f2,l P =Projected fiber surface area fraction for a fiber layer.
Projected Fiber Surface Area Fraction, S f,l P
Assume a panel composed of equal number of slurry and fiber layers. Let the number of these layers be equal to N l and the fiber volume fraction in the panel be equal to V f .
In summary, the projected fiber surface area fraction, S f,l P of a layer of fiber network being deposited over a distinct slurry layer is given by the following mathematical relationship:
S
f
,
l
P
=
4
V
f
t
π
N
l
d
f
=
4
V
f
*
t
s
,
l
π
d
f
(
1
-
V
f
)
where, V f is the total panel fiber volume fraction, t is the total panel thickness, d f is the diameter of the fiber strand, N l is the total number of fiber layers and t s,l is the thickness of the distinct slurry layer being used.
Accordingly, to achieve good fiber embedment efficiency, the objective function becomes keeping the fiber surface area fraction below a certain critical value. It is noteworthy that by varying one or more variables appearing in the Equations 8 and 10, the projected fiber surface area fraction can be tailored to achieve good fiber embedment efficiency.
Different variables that affect the magnitude of projected fiber surface area fraction are identified and approaches have been suggested to tailor the magnitude of “projected fiber surface area fraction” to achieve good fiber embedment efficiency. These approaches involve varying one or more of the following variables to keep projected fiber surface area fraction below a critical threshold value: number of distinct fiber and slurry layers, thickness of distinct slurry layers and diameter of fiber strand.
Based on this fundamental work, the typical magnitudes of the projected fiber surface area fraction, S f,l P have been discovered to be as follows:
Typical projected fiber surface area fraction, S f,l P <0.65
Another range of typical projected fiber surface area fraction, S f,l P <0.45
For a design panel fiber volume fraction, V f , achievement of the aforementioned preferred magnitudes of projected fiber surface area fraction can be made possible by tailoring one or more of the following variables—total number of distinct fiber layers, thickness of distinct slurry layers and fiber strand diameter. In particular, the desirable ranges for these variables that lead to the typical magnitudes of projected fiber surface area fraction are as follows:
Thickness of Distinct Slurry Layers in Multiple Layer SCP Panels, t s,l
Preferred thickness of distinct slurry layers, t s,l ≦0.20 inches
More Preferred thickness of distinct slurry layers, t s,l ≦0.12 inches
Most preferred thickness of distinct slurry layers, t s,l ≦0.08 inches
Number of Distinct Fiber Layers in Multiple Layer SCP Panels, N l
Preferred number of distinct fiber layers, N l ≧4
Most preferred number of distinct fiber layers, N l ≧6
Fiber Strand Diameter, d f
Preferred fiber strand diameter, d f ≧30 tex
Most preferred fiber strand diameter, d f ≧70 tex
In using the panels as structural subflooring or flooring underlayment, they preferably will be made with a tongue and groove construction, which may be made by shaping the edges of the panel during casting or before use by cutting the tongue and groove with a router. Preferably, the tongue and groove will be tapered, as shown in FIGS. 3 and 4 A-C, the taper providing easy installation of the panels of the invention.
Additional details of variations on the process and the amounts of fibers embedded in typical SCP panels for use in the present invention are provided by the following patents and patent applications:
U.S. Pat. No. 6,986,812, to Dubey et al. entitled SLURRY FEED APPARATUS FOR FIBER-REINFORCED STRUCTURAL CEMENTITIOUS PANEL PRODUCTION, herein incorporated by reference in its entirety; and
the following co-pending, commonly assigned, United States patent applications, all herein incorporated by reference in their entirety:
United States Patent Application Publication No. 2005/0064164 A1 to Dubey et al., application Ser. No. 10/666,294, entitled, MULTI-LAYER PROCESS AND APPARATUS FOR PRODUCING HIGH STRENGTH FIBER-REINFORCED STRUCTURAL CEMENTITIOUS PANELS;
United States Patent Application Publication No. 2005/0064055 A1 to Porter, application Ser. No. 10/665,541, entitled EMBEDMENT DEVICE FOR FIBER-ENHANCED SLURRY;
U.S. patent application Ser. No. 11/555,647, entitled PROCESS AND APPARATUS FOR FEEDING CEMENTITIOUS SLURRY FOR FIBER-REINFORCED STRUCTURAL CEMENT PANELS, filed Nov. 1, 2006;
U.S. patent application Ser. No. 11/555,655, entitled METHOD FOR WET MIXING CEMENTITIOUS SLURRY FOR FIBER-REINFORCED STRUCTURAL CEMENT PANELS, filed Nov. 1, 2006;
U.S. patent application Ser. No. 11/555,658, entitled APPARATUS AND METHOD FOR WET MIXING CEMENTITIOUS SLURRY FOR FIBER-REINFORCED STRUCTURAL CEMENT PANELS, filed Nov. 1, 2006;
U.S. patent application Ser. No. 11/555,661, entitled PANEL SMOOTHING PROCESS AND APPARATUS FOR FORMING A SMOOTH CONTINUOUS SURFACE ON FIBER-REINFORCED STRUCTURAL CEMENT PANELS, filed Nov. 1, 2006;
U.S. patent application Ser. No. 11/555,665, entitled WET SLURRY THICKNESS GAUGE AND METHOD FOR USE OF SAME, filed Nov. 1, 2006;
U.S. patent application Ser. No. 11/591,793, entitled MULTI-LAYER PROCESS AND APPARATUS FOR PRODUCING HIGH STRENGTH FIBER-REINFORCED STRUCTURAL CEMENTITIOUS PANELS WITH ENHANCED FIBER CONTENT, filed Nov. 1, 2006;
U.S. patent application Ser. No. 11/591,957, entitled EMBEDMENT ROLL DEVICE, filed Nov. 1, 2006.
Properties
The SCP panel and frame systems employing such SCP panels (prior to including reinforcement) preferably have one or more of the properties listed in TABLES 2A-2D. A number of these properties will be improved by reinforcement while others, for example, mold and bacterial resistance are expected to remain substantially the same.
TABLE 2A
ASTM
Preferred
Physical
Test
Target
Characteristics
Method
Unit
Value
Typical Range
Notes
Non-Combustibility
E-136
Weight
≦50%
≦50%
From Sec. 8, E-136
Loss
Temp
≦54° F.
≦54°
From Sec. 8, E-136
Rise
30
No
No
From Sec. 8, E-136
seconds
flaming
flaming
Water Durability
Flex. Strength of
Sheathing
Dry
C-947
psi
≧1800
1400-3500
Wet
C-947
psi
≧1650
1300-3000
AMOE of Sheathing
Dry
ksi
≧700
600-1000
Wet
ksi
≧600
550-950
Screw Withdrawal
(screw size: #8 wire 1⅝
inch screw with 0.25 inch
diameter head
minimum)
½″ Panel-Dry
D-1761
pounds
352
250-450
Equiv. to American
Plywood Assoc. (APA)
S-4
½″ Panel-Wet
D-1761
pounds
293
200-400
% of force for SCP
relative to OSB 82%; %
of force for SCP relative
to Plywood 80%
¾″ Panel-Dry
D-1761
pounds
522
450-600
Equiv. to American
Plywood Assoc. (APA)
S-4
¾″ Panel-Wet
D-1761
pounds
478
450-550
% of force for SCP
relative to OSB 82%; %
of force for SCP relative
to Plywood 80%
TABLE 2B
ASTM
Preferred
Physical
Test
Target
Characteristics
Method
Unit
Value
Typical Range
Notes
Lateral Screw
Screw size: #8 wire 1⅝
Resistance
inch screw with 0.25 inch
diameter head minimum
½″ Panel-Dry
D-1761
pounds
445
350-550
Equiv. to APA S-4
½″ Panel-Wet
D-1761
pounds
558
400-650
% of force for SCP
relative to OSB 73; % of
force for SCP relative to
Plywood 82%
¾″ Panel-Dry
D-1761
pounds
414
400-500
Equiv. to APA S-4
¾″ Panel-Wet
D-1761
pounds
481
400-500
% of force for SCP
relative to OSB 73; % of
force for SCP relative to
Plywood 82%
Static & Impact Test
(¾ inch thick SCP)
Ultimate
Static
E-661
pounds
1286
1000-1500
APA S-1; 16 inch o.c.
Span Rating ≧ 550 lbs.
Following
E-661
pounds
2206
1500-3000
APA S-1; 16 inch o.c.
Impact
Span Rating ≧ 400 lbs
Deflection under 200
lb. Load
Static
E-661
inches
0.014
0.010-0.060
APA S-1; 16 inch o.c.
Span Rating ≦ 0.078″
Following
E-661
inches
0.038
0.020-0.070
APA S-1; 16 inch o.c.
Impact
Span Rating ≦ 0.078″
Uniform Load
¾″ Panel-Dry
psf
330
300-450
16 inch o.c.
Span Rating ≧ 330 psf
Linear Expansion
½″ to ¾″
APA P-1
%
≦0.1
≦0.1
APA P-1 requires ≦ 0.5%
Panel
TABLE 2C
ASTM
Preferred
Physical
Test
Target
Characteristics
Method
Unit
Value
Typical Range
Notes
Water Absorption
½″ Panel
APA
%
11.8
7 to 15
% water absorption of
PRP-108
SCP relative to ½ inch
thick OSB: 51.5%,
% water absorption of
SCP relative to ½ inch
thick Plywood: 46.2%
¾″ Panel
APA
%
10.8
7 to 15
% water absorption of
PRP-108
SCP relative to
OSB: 51.3%,
% water absorption of
SCP relative to
Plywood: 48.1%
Thickness Swell
½″ Panel
APA
%
2.3
1 to 5
% water absorption of
PRP-108
SCP relative to ½ inch
thick OSB: 22.2%,
% water absorption of SCP
relative to ½ inch
thick Plywood: 7.8%
¾″ Panel
APA
%
2.4
1 to 5
% water absorption of
PRP-108
SCP relative to
OSB: 22.2%,
% water absorption of
SCP relative to
Plywood: 7.8%
Mold & Bacteria
Resistance
½ to ¾″ Panel
G-21
1
0 to 1
OSB & Plywood have
food source
½ to ¾″ Panel
D-3273
10
10
OSB & Plywood have
food source
Termite Resistance
½ to ¾″ Panel
No food
No food
source
source
TABLE 2D
ASTM
Preferred
Physical
Test
Target
Characteristics
Method
Unit
Value
Typical Range
Notes
Horizontal Design
Shear Capacity of
the Floor Diaphragm
¾″ Panel-
E-455
pounds
487.2
300-1000
Performance relates to
10′ × 20′
per
Typically 400-800
panel properties,
Assembly
linear
joist depth & spacing and
foot
fastener type and spacing
System Fire
Resistance
⅝ to ¾″ SCP
E-119
Time
1 hr and
1 to 1.5 hr.
Nominal 4″ deep stud,
Panel on one side of
10 min.
24″ O.C.,
metal frame
batt insulation, 1 layer
⅝″ FIRECODE
Gypsum Board available
from USG.
¾″ Panel SCP on
E-119
Time
1.5 hr to 2 hr -
1 to 2.5 hr
Nominal 10″ deep joist,
one side of metal
9 min
or
24″ O.C.,
frame
1 to 2.25 hr
batt insulation, 1 layer
⅝″ FIRECODE
Gypsum Board available
from USG
¾″ Panel SCP on
E-119
Time
1.5 hr to 2 hr -
1.5 to 2.5 hr
Nominal 10″ deep joist,
one side of metal
9 min
or
24″ O.C.,
frame
1.5 to 2.25 hr
batt insulation, 2 layers
⅝″ FIRECODE
Gypsum Board available
from USG
Horizontal Design Shear Capacity in Table 2D provides for a safety factor of 3.
A typical ¾ inch (19 mm) thick panel when tested according to ASTM 661 and APA S-1 test methods over a span of 16 inches (406.4 mm) on centers, has an ultimate load capacity greater than 550 lb (250 kg), under static loading, an ultimate load capacity greater than 400 lb (182 kg) under impact loading, and a deflection of less than 0.078 inches (1.98 mm) under both static and impact loading with a 200 lb (90.9 kg) load.
Typically, the flexural strength of a panel having a dry density of 65 lb/ft 3 (1040 kg/m 3 ) to 90 lb/ft 3 (1440 kg/m 3 ) or 65 lb/ft 3 (1040 kg/m 3 ) to 95 lb/ft 3 (1522 kg/m 3 ) after being soaked in water for 48 hours is at least 1000 psi (7 MPa), e.g. 1300 psi (9 MPa), preferably at least 1650 psi (11.4 MPa) more preferably at least 1700 psi (11.7 MPa) as measured by the ASTM C 947 test.
Typically the horizontal shear diaphragm load carrying capacity of the system will not be lessened by more than 25%, preferably not be lessened by more than 20%, when exposed to water in a test wherein a 2 (5.1 cm) inch head of water is maintained over ¾ inch (1.9 cm) thick SCP panels fastened on a 10 foot by 20 foot (305×610 cm) metal frame for a period of 24 hours.
Typically the system will not absorb more than 0.7 pounds per square foot of water when exposed to water in a test wherein a 2 inch head of water is maintained over ¾ inch thick SCP panels fastened on a 10 foot by 20 foot (305×610 cm) metal frame for a period of 24 hours.
Typically an embodiment of the present system having a 10 foot wide by 20 foot (305×610 cm) long by ¾ inch thick diaphragm of the SCP panels attached to a 10 foot by 20 foot (305×610 cm) metal frame will not swell more than 5% when exposed to a 2 inch (5.1 cm) head of water maintained over the SCP panels fastened on the metal frame for a period of 24 hours.
Typically, the present reinforced SCP panel meets ASTM G-21 in which the panel achieves approximately a 1 and meets ASTM D-3273 in which the system achieves approximately a 10. Also, typically the present system supports substantially zero bacteria growth when clean. Also, typically the present system is inedible to termites.
Typically a non-combustible system for construction comprising: a shear diaphragm supported on metal frame, the shear diaphragm comprising the panel of the present invention and the frame comprising metal framing members, wherein the panel has a thickness of ¾ inch and has a racking strength ultimate load measured according to ASTM E72 racking from about 4400 to 7400 lbs. (1996 to 3357 kgs.) for an 8 foot by 8 foot wall assembly. This translates to a nominal wall racking shear strength of about 550 lbs per linear foot to 925 pounds per linear foot. For example, the racking strength ultimate load may be in the range of from about 4600 to about 6000 lbs. (2086 to 2721 kgs.) for an 8 foot by 8 foot wall assembly. This translates to a nominal wall racking shear strength of about 575 lbs per linear foot to 750 pounds per linear foot. The assembly for this ASTM E72 racking measurement is single sided and has 16 gage 3⅝ inch studs, 16 inches on center with fasteners 6 inches on center in the perimeter and 12 inches on center in the field. The panels for this ASTM E72 racking measurement are installed horizontally with no blocking in the cavities. The fasteners were #8-18×1⅝ inch long winged DRILLER BUGEL HEAD screws.
Values for wall racking strength can vary for different gauge studs, different stud spacing or different fastener spacing. Thus, a typical range for wall racking strength ranges from 500-7000 plf, nominal racking shear strength.
Wall Racking Strength is expressed in pounds per lineal foot, the ultimate load for a test specimen can be expressed as the max load on the test specimen as an entire unit, or in an ultimate load expressed in pounds per lineal foot, e.g., the width of the specimen.
Typically, the panel when fastened to wall framing has racking shear strength between 1.1 and 3.0 times the racking shear strength of a similar dimensioned (sized) SCP panel without reinforcing fastened to the same wall framing with the same fasteners.
EXAMPLES
Test Specimen Diaphragm Materials
Prototype ¾″ SCP—Structural Cement Panel of the present invention reinforced with fiberglass strands. A “V”-groove and tongue is located along the 8′ dimension of the 4′×8′ (122×244 cm) sheets. The formulation used in the SCP panel examples of this floor diaphragm test is listed in TABLE 3.
TABLE 3
Ingredient
Weight Percent (%)
Reactive Powder Blend
Portland Cement
29
Calcium Sulfate Alpha Hemihydrate
58
Silica Fume
12
Lime
1
SCP Cementitious Composition
Portland Cement
12.2
Calcium Sulfate Alpha Hemihydrate
24.4
Silica Fume
5.1
Lime
0.4
Ceramic Microspheres
27.4
Superplasticizer
1.9
Water
24.2
Alkali-Resistant Glass Fibers 1
4.4
1 Weight proportion corresponds to 1.8% volume fraction of Alkali Resistant Glass Fibers in the composite.
Length of glass fibers used in the floor diaphragm test - 36 mm.
A total of 5 panels were tested. Each panel consisted of the same framing detail (16 ga 3⅝″ (9.2 cm) studs manufactured by Dietrich located 16″ (40.6 cm) on center), fastener layout (6″ (15.2 cm) on center on the perimeter, 12″ (30.5 in the field) and ¾″ SCP panels were all installed horizontally with no blocking in the cavities. All of the assemblies were single sided.
Panel 1 is the base case with no additional metal reinforcement added.
Panel 2 had a full sheet (4′×8′) (122×244 cm) piece of 22 gauge steel bonded to the back side.
Panel 3 had 8″ (20.3 cm) wide strips of 22 gauge steel bonded along the 8′ dimension of the panel (similar to the embodiment of FIG. 5 ). The reinforcements of Panels 3 - 5 are glued to the surface of the panel to protrude from the panel surface.
Panel 4 had 18″×18″ (46×46 cm) gussets bonded to all four corners of each SCP panel (similar to the embodiment of FIG. 10 , but the reinforcements protrude and there are no reinforcing members 56 ).
Panel 5 had 18″×18″ (46×46 cm) gussets with folded over edges bonded to all 4 corners of each SCP panel (similar to Panel 4 but the gussets having folded over edges).
The ultimate loads measured according to ASTM E72 racking were as follows (number in square brackets are the correlating indices):
Panel 1 —4147 lb (1881 kg) [1]
Panel 2 —7651 lb (3470 kg) [1.845]
Panel 3 —5641 lb (2558 kg) [1.360]
Panel 4 —4712 lb (2137 kg) [1.136]
Panel 5 —3828 lb (1736 kg) [0.923]
The failure modes for each panel were as follows:
Panel 1 —fastener pull through around the perimeter
Panel 2 —fastener pull through/shear around the perimeter. Metal unbonded and buckled on backside.
Panel 3 —fastener pull through/shear around the perimeter. Metal unbonded and buckled on backside.
Panel 4 —fastener pull through/shear around the perimeter. Metal unbonded and buckled on backside. Adhesive appeared not to be fully cured and still wet to the touch after test.
Panel 5 —fastener shear around the perimeter initially then bending pull out of fasteners. Metal unbonded and buckled on backside. It should be noted here that due to the bent portion of the gusset that a 3/16″ space was present along the horizontal joint of the assembly. This will adversely affect the performance.
FIG. 34 shows ASTM E72 Racking of these five 8 foot×8 foot samples with SCP installed horizontally on 16 gauge 3.624 steel studs at 16 inches on center with fastener layout of 6″ (15.2 cm) on center on the perimeter and 12″ (30.5 cm) in the field.
While a particular embodiment of the system employing a horizontal diaphragm of fiber-reinforced structural cement panels on a metal frame has been shown and described, it will be appreciated by those skilled in the art that changes and modifications may be made thereto without departing from the invention in its broader aspects and as set forth in the following claims. | This invention relates to a structural cementitious panel (SCP) panel able to resist lateral forces imposed by high wind and earthquake loads in regions where they are required by building codes. These panels may be used for shear walls, flooring or roofing or other locations where shear panels are used in residential or commercial construction. The panels employ one or more layers of a continuous phase resulting from the curing of an aqueous mixture of inorganic binder reinforced with glass fibers and containing lightweight filler particles. One or more reinforcement members, such as mesh or plate sheets, are bonded to at least one surface of the panel to provide a completed panel that can breathe and has weather resistant characteristics to be capable of sustaining exposure to the elements during construction, without damage. | 8 |
FIELD OF THE INVENTION
This invention relates to typewriter and printer paper feeds and particularly to the pressure feed roll/rotary platen type of paper feeds.
BACKGROUND OF THE INVENTION
The simplification of paper feeds is a goal in the design of any typewriter or printer, so long as they may be simplified without reducing reliability in feeding the paper. In an effort to simplify paper feed, a self-aligning and non-adjustable paper feed mechanism is of primary interest. The self-alignment eliminates the need for precise positioning of the paper feed assembly while non-adjustable paper feeds eliminate the expense of manufacturing the adjustment capacity into the paper feed and the expense of performing the adjustments. Simple release controls eliminate assembly problems and thereby tend to reduce manufacturing and assembly costs. The need for a simpler mechanism is dictated by costs and reliability together with the need to automate the assembly of apparatus such as typewriters and printers to be cost effective in the marketplace.
A self-aligning paper feed for a typewriter is disclosed in U.S. Pat. No. 4,364,683 to I. D. Shakib et al. The release of the paper feed disclosed in the Shakib et al patent depends upon the release bail engaging a release surface and pulling the feed roll assembly away from the platen to allow insertion of the paper or movement of the paper with respect to the platen.
The paper feed of the Epson MX80F/T printer is one where a bail has coaxially mounted thereon a pair of feed rolls spaced apart slightly and positioned roughly at the mid point of the bail. The bail is pulled by a spring into a slot in the frame and maintained in that position by a spring. The end of the slot acts as a fulcrum for the bail while the opposite end of the bail is engaged by a control lever and can be forced generally radially outward from the platen axis. With the movement outward, the feed rolls, being mounted at approximately the midpoint of the bail, will then move outward, also in a generally radial direction from the axis of the platen by approximately half the distance the free end of the bail is translated. One disadvantage of this type paper feed is that the feed rolls will have a tendency to exert an uneven force on the platen depending upon the thickness of the paper being fed and particularly when multiple-part forms are being fed. A further disadvantage of this system is that there is no self-aligning capability.
SUMMARY OF THE INVENTION
A self-aligning feed roll assembly is supported on a feed roll bar such that the feed roll bar may be lowered at one end to relieve the engagement between the feed rolls, on the feed roll assembly, and the periphery of the platen and thereby release paper from the printer.
The movement of the paper feed bar is accomplished by a camming member with the cam surface engaging the platen shaft thereby moving the cam generally downward in response to the camming member being pulled forward by the operator. The downward movement of the cam pushes the paper feed bar down and away from the platen, thus relieving the feed roll assembly from the surface of the platen by lowering it.
DRAWING
FIG. 1 is a partially cutaway perspective view of the paper feed assembly.
FIG. 2 is a front view of the paper feed assembly showing the paper feed rolls, the paper feed roll assembly, the paper feed bar, and the engaged and the withdrawn positions.
FIG. 3 is an end view of the paper feed assembly in the engaged position.
FIG. 4 is an end view of the paper feed assembly with the paper feed roll assembly in its withdrawn position.
FIG. 5 is an enlarged perspective view of the portion of the paper feed bar which engages the paper feed roll assembly.
DESCRIPTION OF THE INVENTION
Referring to FIG. 1, which is a partial cutaway view of the paper feed mechanism, a platen 10 is positioned such that platen shaft 12 is supported by frame 14. Frame 14 provides the rigid support necessary to precisely position platen 10 relative to the remainder of the typewriter or printer.
In order to provide the forces necessary to increment the paper about the platen, feed rolls 16, 18 are biasingly engaged with the periphery of the platen 10 on the lower portion of the platen's periphery. Rear feed rolls 16 and front feed rolls 18 are rotatably supported and affixed to shaft 20 and 22, respectively.
To maintain the feed roll shafts 20 and 22 in parallelism, feed roll plates 24 are provided, one of which engages each end of feed roll shafts 20 and 22. Feed roll plates 24 act as supports for the feed roll shafts 20, 22 and at the same time transmit forces to the feed roll shafts 20, 22 to cause the engagement of feed rolls 16, 18 with the periphery of the platen 10. Feed roll plates 24 are maintained at the appropriate spaced apart distance and orientation by paper feed bar 26. Paper feed bar 26 extends entirely across the typewriter or printer and through the frame members 14. Near one end of the paper feed bar 26, a notch 28 (best seen in FIG. 2) is formed on the upper surface thereof for engaging the frame member 14. The notch 28 insures that bar 26 will be laterally positioned appropriately with respect to the frame 14. The bar 26 extends through the frame opening 30 sufficiently to engage notch 28 with frame 14. The opposite end of the paper feed bar 26 extends through a similar but longer dimensioned frame opening 32. The need for the longer dimension is to accommodate downward movement of the paper feed bar 26.
To retain the feed roll plates 24 in the proper lateral position to retain and support the feed roll shafts 20, 22, the paper feed bar 26 is notched at 34 and 36 (FIG. 1). The notches 34 and 36 fit down over mating notches 38 on the feed roll plate 24. The mating of the notches 34, 36 on the paper feed bar 26, with the notches 38 on the feed roll plates, acts to restrain the feed roll plates 24 from lateral movement in any direction along bar 26, thus keeping the feed roll shafts 20 and 22 properly engaged with the platen 10 and keeping the paper feed roll assembly positioned with respect to the platen 10. It should be noted that the notch 36 formed into the paper feed bar 26 is substantially longer than the notch 34. This differenoe in the dimension is to allow some downward movement of paper feed bar 26 prior to the interferring engagement with feed roll plate 24. The dimension of notch 36 may be configured such that engagement with the feed roll plate 24 occurs at substantially the same time as or after engagement of notch 34 with paper feed roll plate 24, thereby causing a release of the engagement between the feed rolls 16 and 18 from the periphery of the platen 10 at approximately the same time.
Feed roll plates 24 have a bifurcated lower end thus forming a pair of fingers 23 and 25 (FIG. 3 and FIG. 4). These fingers 23, 25 extend down over a plate 40 which extends between and is supported by frame members 14. Plate 40 provides the structure against which force may be exerted to cause the biasing of the feed roll plates 24 to raise plates 24 toward platen 10.
To provide this raising force, which positions the feed roll plates 24 adjacent the periphery of platen 10, a centrally bent leaf spring 42 is provided. Spring 42 is configured with two holes 44 near the ends thereof. The ends of spring 42 are inserted through apertures or holes 46 in feed roll plates 24 and will tend, due to the bend 48, to flex the ends upward engaging the upper surface of hole 46. Thus, the spring 42 will act to push the feed roll plates 24 upward, transmitting that bias to the feed rolls 16 and 18 until they engage the periphery of platen 10.
Since there are no permanent fasteners involved in the assembly, it is necessary to be able to assemble the feed roll assembly and the paper feed bar 26 in such a way it will remain assembled during handling so that the total subassembly may be positioned in the machine either manually or by automated mechanical assembly means. In order to retain the assembly in its assembled condition, paper feed bar 26 is formed with outward dog leg or L-shaped extensions 50 depending from paper feed bar 26 near the ends of the bar 26 and spaced approximately the same distance as are the holes 44 in spring 42. Thus, after spring 42 has been inserted through the holes 46 in the feed roll plate 24, the paper feed bar 26 may be positioned onto the feed roll plates 24, engaging the notches 38, and the spring 42 flexed to insert the L-shaped appendages 50 through the holes 44. With the spring 42 relaxed, the holes 44 will be retracted until the holes 44 are incapable of slipping over the L-shaped appendage 50 and thus will retain the paper feed bar 26, the feed roll plates 24 and the feed roll shafts 20 and 22 in assembly.
To assemble the paper feed assembly into the typewriter frame 14, the rightmost end as viewed in FIG. 1 of paper feed bar 26 is inserted into the hole 32 in frame 14 to a sufficient distance to permit the leftmost end of bar 26 to be located within frame 14 and to be aligned with hole 30. When the leftmost end of bar 26 is aligned with hole 30, it is then inserted into hole 30 until notch 28 engages frame 14 at the leftmost end of bar 26. In so doing, fingers 23, 25 of the feed roll plates 24 are positioned astradle plate 40. As the assembly is lowered over plate 40, spring 42 will engage plate 40 in the region of the bend 48 thus flexing the spring 42 upward. After paper feed bar 26 is positioned in its previously described position, the platen 10 may be inserted into frame 14.
In order to retract paper feed bar 26 from platen 10, a simplified paper feed release lever 54 is provided to act in conjunction with the platen shaft 12. Release lever 54 is formed to include not only a handle or other manual control element but also a camming surface 56 formed interiorly thereof. Camming surface 56 is oriented such that a forward pull of the lever 54 against platen shaft 12 will overcome spring 42 and cause a relatively downward movement of lever 54 with respect to shaft 12 (FIG. 4). After the lever 54 has moved downward sufficiently, detent shaft 12 will clear cam 56 at point 57 and shaft 12 will then be positioned in the detenting depression 58. The vertical component of movement of lever 54 is transmitted to paper feed bar 26 by the engagement between notch 60 at the bottom of lever 54 and paper feed bar 26.
Notch 60 insures that the paper feed release lever 54 remains in engagement with paper feed bar 26.
The release of the paper feed assembly by withdrawing the paper feed rolls 16, 18 from engagement with the platen 10 may be continued on an indefinite basis by leaving the paper feed lever 54 in its detented forward position with shaft 12 engaged in the detenting depression 58. This insures that the distance between the top of the paper feed bar 26 and the platen shaft 12 is at its maximum stable distance.
The release of the paper feed assembly may be accomplished by the pushing backward of the paper feed release lever 54 to restore it to an undetented position relative to shaft 12 and allow the spring 42 to urge the paper feed plates 24 upward in response to the flexing of spring 42.
A further improvement for the engagement of spring 42 with the upper surface forming the hole 46 in feed roll plate 24 is the formation of a rounded area depending from holes 46 to form a localized or point bearing surface 70. The bearing surface 70 engaging the spring 42 permits a more even distribution of force between feed rolls 16, 18 and the platen 10, together with an improved self-alignment of the feed roll assembly.
The operation of the entire paper feed release mechanism described above may be best seen in FIG. 2. When paper feed release lever 54 is moved forward (toward the operator), the camming surface 56 causes a downward movement of lever 54 with respect to shaft 12. This downward movement forces the paper feed bar 26 to a displaced position 26' shown in dashed lines. As the paper feed bar 26 rotates downward, its engagement with feed roll plates 24 as has been described above, will cause the paper feed roll plates 24 to likewise move downward. As they are moved downward, they will pull the feed roll shafts 22 and feed rolls 18 downward away from the periphery of platen 10. Likewise, the feed roll shaft 20 and feed rolls 16, not visible in FIG. 2, will be pulled downward and out of engagement with the periphery of platen 10. Flexure of spring 42 due to the downward movement of feed roll plates 24 will store energy in spring 42 sufficient to restore feed roll plates 24, feed roll shaft 20 and 22 and feed rolls 16 and 18 to their raised position upon the return of paper feed release lever 54 to its rearward position. Notch 28 serves as a pivot in conjunction with frame 14.
Operation of paper feed release lever 54 forward positively retracts the feed rolls 16, 18 from the platen 10 and the release of paper feed release lever 54 to its rearward position allows the spring 42 to bias the entire assembly upward until the feed rolls 16, 18 engage platen 10. The paper feed roll assembly may be subassembled and then inserted in one operation into the frame 14 of the typewriter. Removal of the platen 10 from the typewriter will only allow such upward movement of the assembly as is permitted by the holes 30 and 32 inside frame 14. Thus, the assembly may not unintentionally become disengaged from the frame 14 upon the removal of the platen. This assembly will minimize parts and simplify assembly of the typewriter or printer, thereby reducing the cost and making the apparatus more reliable. | A paper feed release system is disclosed wherein a camming member is mounted on and acts with respect to the platen shaft to depress a paper feed release bar extending entirely across the paper feed mechanism such that only one end of said bar is depressed while the second end provides a pivot with respect to the frame supporting the paper feed mechanism. The paper feed rolls and shafts are supported on support plates which are engaged by the paper feed release bar and are caused to be depressed by the pivoting movement of the paper feed release bar with respect to the frame member, under the influence of the camming release member. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of priority of Korean Patent application No. 10-2011-0037607 filed on Apr. 22, 2011, which is incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to wireless communications, and more particularly, to a method and an apparatus of detecting a signal based on a minimum mean square error (MMSE) in a multiple-input multiple-output (MIMO) system.
2. Related Art
A multiple-input multiple-output (MIMO) technology may be applied to a wireless communication system so as to satisfy fast data transmission that is a requirement of a next-generation mobile communication system. The MIMO technology increases channel capacity by using a multiple transmit antenna and a multiple receive antenna without using an additional frequency or transmission power. Further, the MIMO technology can be easily coupled with an orthogonal frequency division multiplexing (OFDM) technology strong against multi path fading. An example of technologies for implementing diversity in the MIMO system may include space frequency block code (SFBC), space time block code (STBC), cyclic delay diversity (CDD), frequency switched transmit diversity (FSTD), time switched transmit diversity (TSTD), precoding vector switching (PVS), spatial multiplexing (SM), or the like. A MIMO channel matrix according to the number of receive antennas and the number of transmit antennas may be decomposed into a plurality of independent channels. Each independent channel may be referred to as a layer or a stream. The number of layers is referred to as a rank.
The MIMO system can improve the channel capacity and the transmitting and receiving efficiency but has a problem of having a plurality of antennas mounted therein. The plurality of antennas may be easily mounted in a base station that can implement relatively complex hardware, but it is not easy to implement a plurality of radio frequency chains in a small user equipment in connection with a size and a cost. Therefore, most of the wireless communication systems to which the MIMO system is applied have two spatial streams.
A receive signal may be detected by calculating a minimum mean square error (MMSE) based log likelihood ratio in the MIMO system having the two spatial streams. A method of calculating MMSE based LLR according to the related art has a small amount of calculations, but when transmit probabilities of all the transmit symbols are the same, has performance lower than a method of calculating optimal LLR capable of achieving the optimal performance.
Therefore, a need exists for a method of calculating LLR based on new MMSE so as to improve reliability of MMSE based LLR calculation.
SUMMARY OF THE INVENTION
The present invention provides a method and an apparatus of detecting a signal based on a minimum mean square error (MMSE) in a multiple-input multiple-output (MIMO) system.
In an aspect, a receiver in a multiple-input multiple-output (MIMO) system is provided. The receiver includes a channel estimator configured for estimating a channel based on a receive signal, a minimum mean square error (MMSE) based reciprocal log likelihood ratio (R-LLR) calculator, coupled to the channel estimator, and configured for calculating an R-LLR based on the receive signal and the estimated channel; and a channel decoder, coupled to the MMSE based R-LLR calculator, and configured for decoding the channel and the receive signal based on the calculated R-LLR, wherein the R-LLR is calculated based on the reciprocity.
In another aspect, a method of detecting a signal in a multi-input multiple-output (MIMO) system is provided. The method includes estimating a channel based on a receive signal, calculating a reciprocal log likelihood ratio (R-LLR) based on the receive signal and the estimated channel, and decoding the channel and the receive signal based the calculated R-LLR, wherein the R-LLR is calculated based on reciprocity.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a receiver to which the present invention is applied.
FIGS. 2 and 3 are diagrams showing that an LLR for each bit is generated through constellation points when a 16 QAM modulation scheme is used.
FIG. 4 shows experimental results showing transmit probabilities of transmit symbols according to whether reciprocity of MMSE solution is established.
FIG. 5 shows an example of a block diagram showing a process of calculating R-LLR by an MMSE based R-LLR calculator.
FIG. 6 shows another example of a block diagram showing a process of calculating R-LLR by an MMSE based R-LLR calculator.
FIG. 7 shows results obtained by calculating priori terms through a simulation experiment according to the method of calculating R-LLR proposed.
FIGS. 8 and 9 are diagrams showing a simple LLR calculation of a first bit and a third bit at the time of calculating the LLR in the simulation experiment.
FIG. 10 is a graph showing performance of the method of calculating R-LLR proposed.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily practice the present invention. However, the present invention may be modified in various different ways and is not limited to the exemplary embodiments provided in the present description. In the accompanying drawings, portions unrelated to the description will be omitted in order to obviously describe the present invention, and similar reference numerals will be used to describe similar portions throughout the present specification. Further, when a detailed description is omitted, only a detailed description of portions that may be easily understood by those skilled in the art will be omitted.
Through the present specification and claims, unless explicitly described otherwise, “comprising” any components will be understood to imply the inclusion of other components rather than the exclusion of any other components.
FIG. 1 is a block diagram of a receiver to which the present invention is applied.
Referring to FIG. 1 , a receiver includes a channel estimator 100 , a minimum mean square error (MMSE) based reciprocal-log likelihood ration (R-LLR) calculator 200 , and a channel decoder 300 . The channel estimator 100 estimates a channel based on a receive signal y. The MMSE based R-LLR calculator calculates an R-LLR based on the receive signal and the estimated channel. The channel decoder 300 decodes the channel and the receive signal based on the calculated R-LLR.
Hereinafter, an operation of the MMSE based R-LLR calculator of FIG. 1 will be described in detail.
In the following description, a thick alphabet small letter represents a vector and a thick alphabet capital represents a matrix. Elements of a vector or a matrix are represented by an italic small letter and a position of each element is represented using a subscript. CN(0, σ2) represents a circular symmetric Gaussian distribution in which a mean is 0 and dispersion is σ2. [•] T represents a transpose of a vector or a matrix and [•] H represents a conjugated transpose of a vector or a matrix. For vector y=[y 1 y 2 . . . y n ], //y// represents l 2 norm and |•| represents an absolute value of a complex point. For two sets, {•}/{•} represent a subtraction operation of a set. For example, {a,b,c}/{a}={b,c}. Ω represents a set of complex constellation points and |Ω| represents the number of constellation points.
The exemplary embodiment of the present invention considers a wireless communication channel configured to include two transmit antennas and n R receive antennas. Equation 1 represents a relationship between the transmit signal and the receive signal.
y
=
Hx
+
z
y
=
[
y
1
y
2
⋯
y
n
R
]
T
x
=
[
x
1
x
2
]
T
z
=
[
z
1
z
2
⋯
z
n
R
]
T
H
=
[
h
11
h
12
h
21
h
22
⋮
⋮
h
n
R
1
h
n
R
2
]
[
Equation
1
]
In Equation 1, y is a receive signal vector, x is a transmit signal vector, z represents a noise vector, and H is a channel gain matrix. x i (i=1,2) represent a signal transmitted from i-th transmit antenna and y j (j=1, 2, . . . , n R ) represents a signal received to a j-th receive antenna. h ji (j=1, 2, . . . , n R , i=1,2) represents a channel gain between an i-th transmit antenna and a j-th receive antenna. Noise z j ˜CN(0,σ z 2) (j=1, 2, . . . , n R ) is assumed to be circular symmetric white Gaussian noise. Further, the transmit signal x i (i=1, 2) is assumed to be symbols modulated by a |Ω|-quadrature amplitude modulation (|Ω|-QAM) scheme.
In order to calculate the MMSE based R-LLR, the MMSE based LLR is first calculated.
Equation 1 may be modified like Equation 2.
y=h 1 x 1 +h 2 x 2 +z [Equation 2]
Where h i =[h 1i h 2i . . . h n R i ] T (i=1,2) represents the i-th column of the channel gain matrix H.
The MMSE solution {tilde over (x)} 1,MMSE for a first stream based on Equation 2 may be represented by the following Equation 3.
x
~
1
,
MMSE
=
w
1
y
=
w
1
h
1
x
1
+
w
1
h
2
x
2
+
w
1
z
=
ρ
x
1
+
I
1
+
z
1
′
≈
x
1
+
z
1
″
[
Equation
3
]
In Equation 3, w 1 =[w 11 w 12 . . . w 1n R ] represents a first row vector of a MMSE filter. If it is assumed that z 1 ″ represented by a sum of interference component I 1 and noise z 1 ′ for the first stream is the circular symmetric white Gaussian noise and the {tilde over (x)} 1,MMSE and {tilde over (x)} 2,MMSE that are the MMSE solution for each stream are independent from each other, a probability density function of a conditional probability where {tilde over (x)} 1,MMSE will be detected may be represented by Equation 4 when transmitting x1.
P
(
x
~
1
,
MMSE
|
x
1
)
=
1
2
πσ
1
2
exp
(
-
|
x
~
1
,
MMSE
-
x
1
|
2
2
σ
1
2
)
[
Equation
4
]
The LLR function for a k-th bit of the first stream may be represented by Equation 5 under the assumption that the transmit probability of all the transmit symbols are the same based on Equation 4.
LLR
(
b
k
,
1
)
=
ln
∑
x
i
∈
S
k
+
p
(
x
i
|
x
~
1
,
MMSE
)
∑
x
j
∈
S
k
-
p
(
x
j
|
x
~
1
,
MMSE
)
=
ln
∑
x
i
∈
S
k
+
p
(
x
~
1
,
MMSE
|
x
i
)
p
(
x
i
)
∑
x
j
∈
S
k
-
p
(
x
~
1
,
MMSE
|
x
j
)
p
(
x
j
)
=
ln
∑
x
i
∈
S
k
+
p
(
x
~
1
,
MMSE
|
x
i
)
∑
x
j
∈
S
k
-
p
(
x
~
1
,
MMSE
|
x
j
)
[
Equation
5
]
Where b k, 1 represents the k-th bit of the first stream, S k + represents the symbol set of which the k-th bit is 1, and S k − represents the symbol set of which the k-th bit is 0.
Equation 6 may be obtained by performing Max-log approximation for Equation 5.
LLR
(
b
k
,
1
)
≈
ln
max
x
i
∈
S
k
+
p
(
x
~
1
,
MMSE
|
x
i
)
max
x
j
∈
S
k
-
p
(
x
~
1
,
MMSE
|
x
j
)
=
1
2
σ
1
2
(
|
x
~
1
,
MMSE
-
x
1
,
k
,
-
opt
|
2
-
|
x
~
1
,
MMSE
-
x
1
,
k
,
+
opt
|
2
)
[
Equation
6
]
In Equation 6,
x
1
,
k
,
+
opt
=
arg
min
x
∈
S
k
+
|
x
~
1
,
MMSE
-
x
|
2
,
x
1
,
k
,
-
opt
=
arg
min
x
∈
S
k
-
|
x
~
1
,
MMSE
-
x
|
2
,
and
σ
1
2
=
E
[
|
I
1
+
z
1
′
|
2
]
≈
E
[
|
I
1
|
2
]
+
E
[
|
z
1
′
|
2
]
=
E
x
|
w
1
h
1
|
2
+
σ
z
2
||
w
1
||
2
.
Equation 6 is the LLR function in the case in which a signal-to-interference noise ratio (SINR) of each stream is different. When the noise power of each stream is the same, the channel decoder outputs the same results by multiplying the same weight by each stream and therefore, may be modified like Equation 6 and Equation 7.
LLR( b k,i )=| {tilde over (x)} i,MMSE −x i,k,− opt | 2 −|{tilde over (x)} i,MMSE −x i,k,+ opt | 2 [Equation 7]
That is, in Equation 7, the LLR may be calculate by a difference in a square of an Euclidean distance between x 1,1,− opt and x 1,1,+ opt for the estimated transmit symbol {tilde over (x)} 1,MMSE ={tilde over (x)} R +j{tilde over (x)} I .
FIGS. 2 and 3 are diagrams showing that an LLR for each bit is generated through constellation points when a 16 QAM modulation scheme is used. FIG. 2 shows that the LLR for the first and second bits are generated and FIG. 3 shows that the LLR for the third and fourth bits are generated.
When using the constellation points in the form as shown in FIGS. 2 and 3 , the LLR for each bit may be calculated by Equations 8 to 11. Equation 8 is an equation of calculating the LLR for the first bit, Equation 9 is an equation for the LLR for the second bit, Equation 10 is an equation of calculating the LLR for the third bit, and Equation 11 is an equation of calculating the LLR for the fourth bit.
LLR
(
b
1
)
=
{
(
x
~
I
-
(
3
)
)
2
-
(
x
~
I
-
(
-
1
)
)
2
=
-
8
x
~
I
+
8
,
x
~
I
>
2
(
x
~
I
-
(
1
)
)
2
-
(
x
~
I
-
(
-
1
)
)
2
=
-
4
x
~
I
,
2
>
x
~
I
>
0
(
x
~
I
-
1
)
2
-
(
x
~
I
-
(
-
1
)
)
2
=
-
4
x
~
I
,
0
>
x
~
I
>
-
2
(
x
~
I
-
1
)
2
-
(
x
~
I
-
(
-
3
)
)
2
=
-
8
x
~
I
-
8
,
-
2
>
x
~
I
[
Equation
8
]
LLR
(
b
2
)
=
{
(
x
~
I
-
3
)
2
-
(
x
~
I
-
1
)
2
=
-
4
x
~
I
+
8
,
x
~
I
>
2
(
x
~
I
-
3
)
2
-
(
x
~
I
-
1
)
2
=
-
4
x
~
I
+
8
,
2
>
x
~
I
>
0
(
x
~
I
-
(
-
3
)
)
2
-
(
x
~
I
-
(
-
1
)
)
2
=
4
x
~
I
+
8
,
0
>
x
~
I
>
-
2
(
x
~
I
-
(
-
3
)
)
2
-
(
x
~
I
-
(
-
1
)
)
2
=
4
x
~
I
+
8
,
-
2
>
x
~
I
[
Equation
9
]
LLR
(
b
3
)
=
{
(
x
~
R
-
(
-
1
)
)
2
-
(
x
~
R
-
(
3
)
)
2
=
8
x
~
R
-
8
,
x
~
R
>
2
(
x
~
R
-
(
-
1
)
)
2
-
(
x
~
R
-
(
1
)
)
2
=
4
x
~
R
,
2
>
x
~
R
>
0
(
x
~
R
-
(
-
1
)
)
2
-
(
x
~
R
-
1
)
2
=
4
x
~
R
,
0
>
x
~
R
>
-
2
(
x
~
R
-
(
-
3
)
)
2
-
(
x
~
R
-
1
)
2
=
8
x
~
R
+
8
-
2
>
x
~
R
[
Equation
10
]
LLR
(
b
4
)
=
{
(
x
~
R
-
3
)
2
-
(
x
~
R
-
1
)
2
=
-
4
x
~
R
+
8
,
x
~
R
>
2
(
x
~
R
-
3
)
2
-
(
x
~
R
-
1
)
2
=
-
4
x
~
R
+
8
,
2
>
x
~
R
>
0
(
x
~
R
-
(
-
3
)
)
2
-
(
x
~
R
-
(
-
1
)
)
2
=
4
x
~
R
+
8
,
0
>
x
~
R
>
-
2
(
x
~
R
-
(
-
3
)
)
2
-
(
x
~
R
-
(
-
1
)
)
2
=
4
x
~
R
+
8
,
-
2
>
x
~
R
[
Equation
11
]
Hereinafter, a method of calculating an MMSE based R-LLR according to the exemplary embodiment of the present invention has been proposed. The calculation of the MMSE based R-LLR proposed in the exemplary embodiment of the present invention defines the reciprocity of the MMSE solution for each stream and uses the fact that only the few transmit candidate vectors including a maximum likelihood (ML) solution achieving the optimal performance is reciprocal when the transmit probabilities of all the transmit symbols are the same. Therefore, the reliability of the MMSE based LLR calculation can be improved. The method of calculating R-LLR proposed by the exemplary embodiment of the present invention determines the LLR of the symbols of the MMSE solution not satisfying the reciprocity as 0 by using the reciprocity information when the SINR information for each stream is not available or the SINRs for each stream are the same. Therefore, it is possible to prevent the LLR having the high erroneous probability from being used for the channel decoding and to improve the reliability of the LLR calculation. Further, when the SINR information for each stream is available or the SINRs for each stream are different, a priori term removed under the assumption that the transmit probabilities of all the transmit symbols are the same is calculated using the reciprocal information. Therefore, the reliability of the LLR calculation can be increased.
First, the reciprocity is defined. When the channel H and the receive signal vector y are given, if the two-dimensional complex vector xεΩ2 satisfies Equation 12, the vector x may be defined as having the reciprocity.
[
x
1
x
2
]
=
[
Q
(
h
1
H
||
h
1
||
2
(
y
-
h
2
x
2
)
)
Q
(
h
2
H
||
h
2
||
2
(
y
-
h
1
x
1
)
)
]
[
Equation
12
]
Function Q(•) represents a slicing function defined by Equation 13.
Q
(
x
^
)
=
arg
min
x
∈
Ω
|
x
-
x
^
|
[
Equation
13
]
FIG. 4 shows experimental results showing transmit probabilities of transmit symbols according to whether reciprocity of MMSE solution is established or not. The simulation experiment environment is shown in Table 1.
TABLE 1
System Model
2x2 MIMO System (Spatial Multiplexing)
Channel Model
IID(Independent and Identically Distributed)
Rayleigh fading channel
(8 independent 2x2 channels in a codeword)
Channel Estimation
Ideal CSI at Rx
Modulation Scheme
16 QAM
Referring to FIG. 4 , if the {circumflex over (x)} MMSE that is the sliced MMSE solution has reciprocity, when the SNR is 0 dB, the transmit probabilities of all the transmit symbols are the same as 1/16. However, it can be appreciated that as the SNR is increased, the transmit probability can be exponentially increased. When the SNR is 20 dB or more, the transmit probability exceeds 0.95, and the transmit probability is approximately converged to 1. On the other hand, if the {circumflex over (x)} MMSE has no reciprocity, when the SNR is 0 dB, the transmit probability of the transmit symbol is lower than 1/16 and the transmit probability is not greatly increased even when the SNR is increased. As a result, it can be appreciated that the transmit probability is approximately converged to 0. That is, when the reciprocity of the MMSE solution is established, it can be appreciated that the LLR has the high reliability.
When the SINR information for each stream cannot be used or the SINRs for each stream are the same, the method of calculating R-LLR will be described. The method of calculating R-LLR proposed determines that the estimated transmit symbol statistically has the high reliability when the reciprocity is established based on the fact that only the few solutions including the ML solution are established to calculate the LLR, thereby detecting the transmit signal and determines that the estimated transmit symbol statistically has low reliability when the reciprocity is not established, thereby determining the LLR as 0.
FIG. 5 shows an example of a block diagram showing a process of calculating R-LLR by an MMSE based R-LLR calculator.
At S 201 , the MMSE based R-LLR calculator estimates the transmit symbols by calculating the MMSE solution based on the receive signal vector and the estimated channel gain matrix. At S 202 , the MMSE based R-LLR calculator performs the slicing on the estimated transmit symbol. At S 203 , the MMSE based R-LLR calculator tests the reciprocity of the sliced transmit symbol. At S 204 , the MMSE-based R-LLR calculator calculates the LLR based on the estimated transmit symbol, the sliced transmit symbol, and the establishment or not of the reciprocity. In this case, the LLR of the symbols of the MMSE solution not satisfying the reciprocity is determined as 0 and the LLR of the symbols of the MMSE solution satisfying the reciprocity is calculated by the above-mentioned method.
Representatively, the ML solution satisfies the reciprocity. The ML solution may be defined by the solution satisfying Equation 14.
min
x
∈
C
2
||
y
-
Hx
||
=
min
x
j
∈
C
||
y
-
h
i
x
i
,
ML
-
h
j
x
j
||
[
Equation
14
]
In addition, the unit vector may be defined as the following Equation 15.
ξ
j
=
h
j
||
h
j
||
[
Equation
15
]
Equation 16 may be represented by the above Equation 15.
y−h i x i,ML =αξ j +βξ j ⊥ [Equation 16]
In Equation 16, α=ξ j H (y−h i x i,ML ).
β
=
||
y
-
h
i
x
i
-
αξ
j
||
,
ξ
j
⊥
=
y
-
h
i
x
i
-
αξ
j
β
.
When Equation 15 and Equation 16 are substituted into Equation 14, an object function of the right of Equation 14 may be represented by Equation 17.
||
y
-
h
i
x
i
,
ML
-
h
j
x
j
||
2
=
||
α
ξ
j
+
β
ξ
j
⊥
-
||
h
j
||
x
j
ξ
j
||
2
=
||
(
α
-
x
j
||
h
j
||
)
ξ
j
+
βξ
j
⊥
||
2
=
|
α
-
x
j
||
h
j
||
|
2
+
|
β
|
2
[
Equation
17
]
In Equation 17, it can be appreciated that |β| is a constant for the given regardless of x j . Therefore, instead of the object function of the right of Equation 14, the solution satisfying |α−x j ∥h j ∥| becomes the ML solution.
Meanwhile, |α−x j ∥h j ∥| may be represented by Equation 18.
|
α
-
x
j
||
h
j
||
|
=
|
h
j
H
||
h
j
||
2
(
y
-
h
i
x
i
,
ML
)
-
x
j
|
[
Equation
18
]
Equation 19 may be obtained according to the definition of Equation 18 and the slicing function.
x
j
,
ML
=
Q
(
h
j
H
||
h
j
||
2
(
y
-
h
i
x
i
,
ML
)
)
[
Equation
19
]
In Equation 19, h i =[h 1i h 2i . . . h n R i ] T (iεI) represents the i-th column of the channel gain matrix H and Q(•) is the slicing function. Referring to Equation 19, it can be appreciated that the ML solution of Equation 19 satisfies the form defined in Equation 12. That is, it can be appreciated that the ML solution satisfies the reciprocity like Equation 20.
x
ML
=
[
x
1
,
ML
x
2
,
ML
]
=
[
Q
(
h
1
H
||
h
1
||
2
(
y
-
h
2
x
2
,
ML
)
)
Q
(
h
2
H
||
h
2
||
2
(
y
-
h
1
x
1
,
ML
)
)
]
[
Equation
20
]
Table 2 shows an example of a pseudo code representing the process of calculating R-LLR of FIG. 5 .
TABLE 2 {circumflex over (x)} MMSE = Q({tilde over (x)} MMSE ) if [ x ^ 1 , MMSE x ^ 2 , MMSE ] == [ Q ( h 1 H h 1 2 ( y - h 2 x ^ 2 , MMSE ) ) Q ( h 2 H h 2 2 ( y - h 1 x ^ 1 , MMSE ) ) ] , conventional LLR w / o SINR using x ~ MMSE else LLR = 00000000
When the SINR information for each stream can be used or the SINRs for each stream are not the same, the method of calculating R-LLR will be described below. The method of calculating R-LLR proposed calculates the priori terms omitted under the assumption that the transmit probabilities of all the transmit symbols are the same by the results obtained through the simulation experiment and uses the calculated results. The method of calculating R-LLR proposed is effective in the method of calculating LLR considering the SINR represented by Equation 6.
FIG. 6 shows another example of a block diagram showing a process of calculating R-LLR by an MMSE based R-LLR calculator.
At 5205 , the MMSE based R-LLR calculator estimates the transmit symbols by calculating the MMSE solution based on the receive signal vector and the estimated channel gain matrix. At S 206 , the MMSE based R-LLR calculator performs the slicing on the estimated transmit symbol. At S 207 , the MMSE based R-LLR calculator tests the reciprocity of the sliced transmit symbol. At S 208 , the MMSE-based R-LLR calculator calculates the LLR based on the estimated transmit symbol and the sliced transmit symbol. At S 209 , the MMSE based R-LLR calculator calculates the R-LLR in which the priori term is added to the LLR based on the calculated LLR and whether the reciprocity is established. In this case, the LLR of the symbols of the MMSE solution satisfying the reciprocity becomes a value obtained by adding the priori term to the LLR calculated by the above-mentioned method.
The R-LLR in which the LLR is added to the priori term may be represented by Equation 21.
LLR
(
b
k
,
1
)
≈
ln
max
x
i
∈
S
k
+
p
(
x
~
1
,
MMSE
|
x
i
)
p
(
x
i
)
max
x
j
∈
S
k
-
p
(
x
~
1
,
MMSE
|
x
j
)
p
(
x
j
)
=
1
2
σ
1
2
(
|
x
~
1
,
MMSE
-
x
1
,
k
,
-
opt
|
2
-
|
x
~
1
,
MMSE
-
x
1
,
k
,
+
opt
|
2
)
+
ln
p
(
x
1
,
k
,
+
opt
)
p
(
x
1
,
k
,
-
opt
)
[
Equation
21
]
In Equation 21, the priori term may be represented by Equation 22.
ln
p
(
x
1
,
k
,
+
opt
)
p
(
x
1
,
k
,
-
opt
)
=
{
ln
p
(
x
1
,
k
,
+
opt
|
x
^
MMSE
rcp
)
-
ln
1
-
p
(
x
i
,
k
,
+
opt
|
x
^
MMSE
rcp
)
|
Ω
|
-
1
,
if
x
^
MMSE
is
reciprocal
0
,
else
[
Equation
22
]
FIG. 7 shows results obtained by calculating priori terms through a simulation experiment according to the method of calculating R-LLR proposed. The graph of FIG. 7 may be considered as a straight line having a slope of about ¼. That is, Equation 22 may approximate like Equation 23.
ln
p
(
x
i
,
k
,
+
opt
)
p
(
x
i
,
k
,
-
opt
)
≈
{
1
4
SNR
dB
,
if
reciprocal
0
,
else
[
Equation
23
]
Table 3 shows an example of a pseudo code representing the process of calculating R-LLR of FIG. 6 .
TABLE 3
{circumflex over (x)} MMSE = Q({tilde over (x)} MMSE )
if
[
x
^
1
,
MMSE
x
^
2
,
MMSE
]
==
[
Q
(
h
1
H
h
1
2
(
y
-
h
2
x
^
2
,
MMSE
)
)
Q
(
h
2
H
h
2
2
(
y
-
h
1
x
^
1
,
MMSE
)
)
]
,
LLR
(
b
k
)
=
1
2
σ
1
2
(
x
~
1
,
MMSE
-
x
1
,
k
,
-
opt
2
-
x
~
1
,
MMSE
-
x
1
,
k
,
+
opt
2
)
+
ln
p
(
x
1
,
k
,
+
opt
)
p
(
x
1
,
k
,
-
opt
)
else
LLR
(
b
k
)
=
1
2
σ
1
2
(
x
~
1
,
MMSE
-
x
1
,
k
,
-
opt
2
-
x
~
1
,
MMSE
-
x
1
,
k
,
+
opt
2
)
However, the performance of the method of calculating R-LLR proposed through the simulation experiment compares with the performance of the method of calculating LLR according to the related art. The simulation experiment environment is shown in Table 4.
TABLE 4
System Model
2x2 MIMO System (Spatial multiplexing)
Channel Model
IID(Independent and Identically Distributed)
Rayleigh fading channel
(8 independent 2x2 channels in a codeword)
Channel Estimation
Ideal CSI at Rx
Modulation Sheme
16 QAM
Frame Size
2568 bits
(648 symbol time * 2 streams * 4 bits *
½ coding rate - 6 CC tail)
Error Correction Encoder
Convolutional Coding (K = 7, rate = ½)
Interleaving
Bit interleaved coded modulation (BICM)
FIGS. 8 and 9 are diagrams showing a simple LLR calculation of a first bit and a third bit at the time of calculating the LLR in the simulation experiment. FIG. 8A shows general LLR calculation for the first bit, FIG. 8B shows a simplified LLR calculation for the first bit, FIG. 9A shows general LLR calculation for the third bit, and FIG. 9B shows a simplified LLR calculation for the third bit.
FIG. 10 is a graph showing performance of the method of calculating R-LLR proposed. Referring to FIG. 10 , when the SINR information for each stream cannot be used or the SINRs for each stream are the same, it can be appreciated that the method for calculating R-LLR proposed has a performance gain of about 5.5 dB as compared with the method of calculating LLR according to the related art, when the forward error rate (PER) is 10-2. Due to the diversity order, the higher the SNR, the higher the performance gain can be obtained. In addition, when the SINR information for each stream can be used or the SINRs for each stream are not the same, it can be appreciated that the method of calculating R-LLR proposed has the performance gain of about 1 dB at the FER as compared with the method of calculating LLR according to the related art. Due to the diversity order, it is predicted that the higher the SNR, the higher the performance gain can be obtained.
The exemplary embodiments of the present invention may be implemented by hardware, software, or a combination thereof. The hardware may be implemented by an application specific integrated circuit (ASIC), digital signal processing (DSP), a programmable logic device (PLD), a field programmable gate array (FPGA), a processor, a controller, a microprocessor, other electronic units, or a combination thereof, all of which are designed so as to perform the above-mentioned functions. The software may be implemented by a module performing the above-mentioned functions. The software may be stored in a memory unit and may be executed by a processor. The memory unit or a processor may adopt various units well-known to those skilled in the art.
The exemplary embodiments of the present invention can improve the performance of the receiver in the MIMO system by calculating the MMSE based reciprocal log likelihood ration (R-LLR) based on the reciprocity.
In the above-mentioned exemplary system, although the methods have described based on a flow chart as a series of steps or blocks, the present invention is not limited to a sequence of steps but any step may be generated in a different sequence or simultaneously from or with other steps as described above. Further, it may be appreciated by those skilled in the art that steps shown in a flow chart is non-exclusive and therefore, include other steps or deletes one or more steps of a flow chart without having an effect on the scope of the present invention.
The above-mentioned embodiments include examples of various aspects. Although all possible combinations showing various aspects are not described, it may be appreciated by those skilled in the art that other combinations may be made. Therefore, the present invention should be construed as including all other substitutions, alterations and modifications belong to the following claims. | A receiver in a multiple-input multiple-output (MIMO) system is provided. The receiver includes a channel estimator estimating a channel based on a receiving signal, a minimum mean square error (MMSE) based reciprocal log likelihood ratio (R-LLR) calculator connected with the channel estimator and calculating an R-LLR based on the receiving signal and the estimated channel, and a channel decoder connected with the MMSE based R-LLR calculator and decoding the channel and the receiving signal based on the calculated R-LLR, wherein the R-LLR is calculated based on the reciprocity. | 7 |
RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 10/762,652 filed Jan. 22, 2004, which claims priority of U.S. Provisional Patent Application Ser. No. 60/442,114 filed Jan. 23, 2003, which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates generally to stabilized steroid compositions. More specifically, the invention relates to compositions and methods for stabilizing hydrocortisone compounds. Still more specifically, the invention relates to methods for stabilizing 17-substituted hydrocortisone compounds. Most specifically, the invention relates to methods and compositions for stabilizing hydrocortisone 17-butyrate.
BACKGROUND OF THE INVENTION
[0003] Hydrocortisone compounds have a very strong anti-inflammatory effect on many tissues. Consequently, these materials are often employed as topical agents for the relief of various inflammations. Hydrocortisone esters are one preferred class of steroidal anti-inflammatory agents, and hydrocortisone 17-butyrate (HC17-B) is one particularly preferred hydrocortisone material which is in widespread use as a therapeutic agent.
[0004] In this description, conventional IUPAC numbering will be followed for steroid molecules. Shown below is the molecular structure of HC17-B. As can be seen, the butyrate moiety is joined to the molecule at the 17 position.
[0005] One problem which has been encountered in connection with HC17-B formulations is that the molecule is prone to rearrange so as to form an isomer in which the butyrate group is attached to the remainder of the molecule through the 21 position. This isomer is generally referred to as HC21-B. Similar rearrangements occur in other hydrocortisone 17-esters.
[0006] This isomerization reaction is generally enhanced when materials such as HC17-B are in a solution or dispersion, as they usually are in a pharmaceutical formulation such as a topical lotion or cream. Isomerization is of particular concern to pharmaceutical formulators since the isomerization reaction raises therapeutic and regulatory issues regarding the efficacy and composition of isomerized compositions. Therefore, the pharmaceutical industry has sought methods and materials whereby steroid compositions such as HC17-B can be stabilized against isomerization or other degradation. However, any such methods or materials should be compatible with the intended therapeutic utility of the hydrocortisone composition; and in this regard, resultant compositions should be effective and nontoxic. Ideally, any such method should employ materials which have previously been demonstrated to be safe.
[0007] As will be explained hereinbelow, the present invention provides materials and methods for inhibiting the degradation of HC17-B and the like. The materials and methods of the present invention are easy to implement, low in cost, safe, and are compatible with pharmaceutical compositions and methods of the type generally employed in connection with hydrocortisone containing agents.
SUMMARY OF THE INVENTION
[0008] Disclosed and claimed herein is a method of stabilizing 17-substituted hydrocortisone compounds, as well as the stabilized 17-substituted hydrocortisone compounds themselves. The method comprises the step of adding a quantity of an omega-6 acid, either in free form or as a compound such as an ester, to a 17-substituted hydrocortisone composition.
[0009] In a particularly preferred embodiment of the method of the present invention, the omega-6 acid comprises linoleic acid. Since safflower oil is a triglyceride which includes an ester of linoleic acid, the omega-6 acid component may be added to the 17-substituted hydrocortisone composition in the form of safflower oil. Safflower oil is, itself, an effective emollient and enhances the skin treatment properties of the stabilized composition. In a particularly preferred embodiment, the safflower oil is added to the hydrocortisone composition in an amount such that the linoleic acid component is present in an at least equimolar proportion to the hydrocortisone. It has been found that it is highly desirable to add the safflower oil to the composition at a weight percent which is in considerable excess to the weight percent of the hydrocortisone, such as ten, twenty, thirty or more times as much.
[0010] Practicing the method of the present invention, the 17-substituted hydrocortisone may comprise hydrocortisone 17-butyrate.
[0011] In addition to the 17-substituted hydrocortisone and omega-6 acid, the composition of the present invention may further comprise a number of other compounds typically found in pharmacological hydrocortisone creams and lotions, such as various alcohols, mineral oil, white petroleum, preservative such as BHT, propylparaben and/or butylparaben, citric or other mild acids, sodium citrate, glycerin, fragrances, coloring agents, etc. Generally speaking, the majority of the composition of the present invention will constitute purified water.
DETAILED DESCRIPTION OF THE INVENTION
[0012] In accord with the present invention, it has been unexpectedly found that the presence of an omega-6 acid component, comprising either the free acid or a derivative thereof such as an ester or the like (“omega-6 acid component”), will inhibit the isomerization of 17-substituted hydrocortisones and other steroid materials. The present invention has particular utility in the stabilization of hydrocortisones having an ester moiety at the 17 position, and is particularly useful in stabilizing HC17-B, and will be described with particular reference to the stabilization of HC17-B.
[0013] There are a variety of omega-6 acids which function to stabilize the substituted hydrocortisones. “Omega-6” signifies that the first double bond in the acid, counting from the end opposite the acid group, occurs in the sixth carbon-carbon bond. There is some confusion due to the fact that there are various nomenclature and numbering systems used for fatty acids. Hence materials of the present invention have been referred to as “omega-3” acids, as well as by other names. In any event, within the context of this disclosure, the foregoing definition of omega-6 acids is utilized. Linoleic acid, also known as 9,12-octadecadienoic acid, is one omega-6 acid having utility in the present invention. Linoleic acid is generally a very safe material, and is readily available. Safflower oil is a triglyceride, comprising a fatty acid ester of glycerol, and it contains large amounts of linoleic acid in esterified form, and in particular embodiments of the present invention, safflower oil is used as a stabilizing agent for HC17-B and similar materials. Safflower oil is particularly advantageous for use in pharmaceutical compositions, since it is generally nontoxic, and has been approved for both topical and internal formulations. Additionally, safflower oil, as well as other omega-6 acid materials, have additional beneficial effects in topical formulations since they can enhance skin penetration and restore lipid content to the skin.
[0014] Other omega-6 acids include arachidonic acid. Yet other polyunsaturated omega-6 acids are known in the art. Such omega-6 acids, as well as their esters and like compounds, may also be used in the present invention.
[0015] In general, the omega-6 acid component will be present in an amount which is at least equimolar with the steroid compound which is to be stabilized. In most practical formulations, the omega-6 acid component is present in a relatively large excess, since it further functions as a skin conditioning agent. For example, it may be present in a weight percentage ten, twenty, thirty or even more times the weight percentage of the steroid compound.
EXAMPLE
[0016] Two experimental hydrocortisone 17-butyrate formulations were prepared. One (formulation R6546) contained a substantial weight percentage (3.0% w/w) of refined safflower oil. The other formulation (R6539) was similar in composition to the first formulation, but lacked any safflower oil. In both formulations, the HC17-B was present in a weight percentage of 0.1. Table 1 shows, respectively, the recipes for the two formulations, showing the various components respectively thereof as weight percentages.
TABLE 1 R6546 R6539 %, %, Ingredient w/w Ingredient w/w Ceteth-20 2.0 Ceteth-20 2.0 Cetostearyl alcohol 4.0 Cetostearyl alcohol 4.0 White petrolatum 2.5 White petrolatum 2.5 Light mineral oil 5.5 Light mineral oil 7.5 Safflower oil 3.0 Propylparaben 0.1 BHT 0.02 Butylparaben 0.05 Propylparaben 0.1 Hydrocortisone 17-butyrate 0.1 Butylparaben 0.05 Citric acid 0.42 Hydrocortisone 17-butyrate 0.1 Sodium citrate (dehydrate) 0.32 Citric acid 0.42 Purified water 83.01 Sodium citrate (dehydrate) 0.32 Purified water 81.99
[0017] Table 2 shows the analytic results of samples of the resultant respective compositions, showing the exact percentages of the HC17-B (as well as propylparaben and butylparaben) found in the two formulations expressed as weight percentages.
TABLE 2 HCB Propylparaben Butylparaben (%, w/w) (%, w/w) (%, w/w) R6539 Sample #1 0.104 0.104 0.052 Sample #2 0.103 0.103 0.051 Average 0.104 0.104 0.052 R6546 Sample #1 0.100 0.102 0.051 Sample #2 0.101 0.102 0.050 Average 0.101 0.102 0.051
From Table 2, it can be ascertained that the formulation containing the safflower oil had an average weight percentage of 0.101 HC17-B, whereas the sample which did not contain the safflower oil had an average weight percentage of HC17-B of 0.104, a slightly greater weight percentage.
[0018] The stability of the respective formulations was tested by analyzing the two formulations over a six-month period, at various intervals. The stability study was performed at a temperature of 40° Centigrade, considerably greater than normal room temperature.
TABLE 3 HCB Propylparaben Butylparaben HC21-B Other impurities (%, w/w) (%, w/w) (%, w/w) (%) (%) R6539 1-month 0.102 0.103 0.052 0 0 2-month 0.100 0.101 0.051 0 0 3-month 0.095 0.100 0.050 — — 6-month 0.086 0.100 0.050 6.36 2.81 R6546 1-month 0.103 0.103 0.051 0 0 2-month 0.101 0.102 0.052 0 0 3-month 0.099 0.103 0.051 2.51 0.45 6-month 0.095 0.102 0.052 5.00 0.56
[0019] As can be readily ascertained by comparing the six-month results for the two compositions, the composition containing the safflower oil (R6546) did lose some HC17-B. The weight percentage went from 0.101 at the start of the study (from Table 2) to 0.095 after six months. Furthermore, the isomer HC21-B began to make its appearance at the three-month interval, and was found at the six-month endpoint of the study in a concentration of 5.00 weight percent of the HC17-B content. Furthermore, there were various other impurities found at the six-month endpoint in a percentage of 0.56 weight percent.
[0020] In contrast, the formulation which did not contain the safflower oil (R6539), although starting out containing slightly more HC17-B, it lost this component more rapidly and wound up with a considerably lower weight percentage of 0.86 at the six-month endpoint of the study. As would be expected, the formulation without the safflower oil and its constituent linoleic acid contained an even larger percentage of the isomer HC21-B, namely, 6.36%. Furthermore, other impurities were found in this formulation after six months in a much larger percentage as well, namely, 2.81 weight percent as compared to only 0.56 weight percent.
[0021] As can be seen from this data, adding the omega-6 acid component in the form of the linoleic acid-containing safflower oil considerably increased the stability of the valuable hydrocortisone 17-butyrate compound. In fact, the formulation which did not contain the safflower oil lost approximately 18% of its original HC17-B, whereas the formulation containing the safflower oil lost only approximately 6%. In other words, the improvement in stability was practically threefold. Furthermore, the level of the HC21-B isomer and the other impurities was about 60% less in the formulation containing the safflower oil than in the formulation where the safflower oil was absent.
[0022] Thus, adding an omega-6 acid component in the form of safflower oil has been shown to be an effective way of stabilizing 17-substituted hydrocortisone compounds. While the methods and compositions of the present invention have been described with reference to certain exemplifications and embodiments thereof, the invention is by no means limited to the specifically depicted examples and embodiments. For example, other 17-substituted hydrocortisone compounds could also be stabilized through the use of the present invention. The omega-6 acid component could be provided in other forms than as linoleic acid generally, or as safflower oil specifically. It is only necessary that the omega-6 acid component be provided in a form which is pharmacologically compatible with topical hydrocortisone creams and lotions. Doubtless, one of skill in the art could, after routine experimentation, employ other pharmacologically compatible omega-6 components with similar efficacy without departing from the scope of the present invention. It is the claims appended hereto, rather than the exact exemplifications and embodiments, which define the scope of the present invention. | Stabilized, 17-substituted hydrocortisone containing compositions and methods of manufacture are disclosed. Isomerization of the hydrocortisone component of topical steroid compositions is markedly reduced by including an omega-6 acid component in the form of a free acid or as a compound such as an ester. Specifically disclosed are methods for preventing the isomerization of hydrocortisone 17-butyrate into hydrocortisone 21-butyrate through the use of safflower oil. | 0 |
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. Provisional Patent Application No. 61/958,040 filed on Jul. 18, 2013 and is a Continuation in Part of U.S. application Ser. No. 13/985,441 filed on May 2, 2013, both of which are incorporated by reference herein in their entirety.
TECHNICAL FIELD
[0002] The present invention relates to the field of filters used to eliminate contaminants from liquids.
BACKGROUND OF THE INVENTION
[0003] Systems which involve liquid flow are frequently are plagued with blockages and restrictions caused by foreign contaminants. Because liquid systems cannot remain contaminant free, a liquid filtering system is always required. Contaminants within a fluid/liquid system exist due to many factors. The simple process of assembling and handling the fluid system parts and components often introduces undesirable contaminants. The act of turning a threaded pipe or fitting into a mating component often shears off thread burrs, allowing the burrs to flow through the liquid system. Small pieces of weld slag, grains from the foundry or cast core sand may be involved. Foreign matter may be deposited during storage of replacement piping and then released during assembly. Component wear and tear will introduce contaminants into the system. Contaminants may be introduced along with the desired fluids when fluid is added to the system. For these and many more reasons, a liquid system requires that a filtering system be in place and maintained.
[0004] The ideal liquid filtering system will remove all foreign contaminants from the liquid without impeding fluid flow through the system as demanded by the pump. Other desirable characteristics include: low cost, high capacity, small size and easy maintainability. There are three main types of filtration systems: mechanical, adsorbent, and absorbent. Typical liquid processing systems include some combination of these three types of filter.
[0005] Mechanical filters are probably the most common in industrial liquid systems. The liquid is forced by pressure through the filter element. The filter is composed of micro-openings, pores or tortuous passages that block and capture larger sizes particles. This type of filter, commonly referred to as a surface type filter, is normally composed of woven fabric, metallic or synthetic screens and/or absorbent paper or paper like materials. The constituent parts of such filters must be compatible with the process liquid and with the expected contaminants. Fire resistance (as applicable), resistance to collapse (due to pressure differential), and compatibility with system temperature are other important issues to consider in choosing a filter. Filters may be constructed of pleated stainless steel, Monel wire and synthetic woven materials.
[0006] Adsorbent filters are typically include porous materials such as cotton, paper, wood, cloth, asbestos, etc. Adsorption is a process wherein contaminants adhere to the surface or surfaces of a filter member rather that being trapped within a filter member. In general this type filter is used to filter fine soluble's and may be designed to allow selected dirty liquid through relatively thick layers with an increase in compactness of the filter material in the direction of flow.
[0007] Absorbent filters function by absorbing and trapping contaminants within a filter member. Examples of absorbent filter material include fuller's earth, boneback, ceramic, graphite, grapheme, charcoal, activated carbon, activated clay, copper, silver, platinum, gold, or other metals or metal compounds, chelating agents, or chemically treated organic mediums applicable to the filtration of oil, fuel, syngas, natural gas or other petroleum or alcohol based products. This type of liquid filtering system may be in the form of gravity feed bed or even a cartridge type installation. This system presents a large surface area through which the liquid flows. The insoluble oxidation products and solid contaminants are removed by size filtration and absorption.
SUMMARY OF THE INVENTION
[0008] In accordance with the present invention, there is provided a multistage filter capable of filtering contaminants from a liquid flowing under pressure into said multistage filter, said multistage filter comprising, consisting of , or consisting essentially of an outer cylindrical shell having a first end sealed, a second end containing a central outlet port and at least one inlet port near a peripheral edge thereof. The cylindrical shell contains at least two concentric cylindrical filter media. The ends of the two cylindrically shaped media are fluidly sealed against the inner surfaces of the first sealed end and the second end of the cylindrical shell. The at least one inlet port is in fluid communication with the outer surface of the first outer cylindrical stage. The central outlet port is in fluid communication with the inner surface of the innermost one of the at least two concentric cylindrically shaped filter media. The innermost one of said at least two concentric cylindrically shaped filter media comprising ceramic and including a filter coating on an inner surface thereof.
[0009] It is an object of this invention to provide a multistage canister filter which includes a plurality of stages or layers of filtering material of differing porosities.
[0010] It is an object of this invention to provide a multistage canister filter wherein all of the incoming liquid is forced through the first and then subsequent stages so that no amount of the incoming liquid is allowed to bypass any one stage of the multistage filter.
[0011] It is an object of this invention to provide a multistage canister filter wherein the first stage blocks contaminants of the largest size and allows the liquid and the smaller contaminants to pass to the next stage, the next stage traps the next largest size contaminants and so on and so on until the liquid is acceptably free of all undesirable contaminants.
[0012] It is an object of this invention to provide a multistage canister filter wherein all of the filter stages include one or more of the following elements: metallic or synthetic mesh type screen, stranded meshes, fibrous tissues, paper and/or paper-like materials, metallic screens, ceramic discs and ceramic tubes.
[0013] It is an object of this invention to provide a multistage canister filter wherein the final stage includes a cylindrical ceramic filter media where the inner surface of the ceramic includes a coating which further catches selected contaminants which are able to pass through the ceramic filter media.
[0014] It is an object of the present invention to provide filters or coatings on filters which function as chelating agents which chemically react with selected compounds.
[0015] It is another object of the present invention to provide filter material or filter coated material which adsorbs selected molecules of a particular compound due to ionic attraction or molecular size.
[0016] It is another object of the present invention to provide filter material which can adsorbed by activated charcoal or coat a charcoal or ceramic material which is reacts with and combines to hold selected chemical compounds.
[0017] Other objects, features, and advantages of the invention will be apparent with the following detailed description taken in conjunction with the accompanying drawings showing a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] A better understanding of the present invention will be had upon reference to the following description in conjunction with the accompanying drawings in which like numerals refer to like parts throughout the views wherein:
[0019] FIG. 1 is a cross-sectional view of a multistage canister filter showing the various filter elements.
[0020] FIG. 2 is an end view of a multistage canister filter showing the central outlet port and the plurality of outer inlet ports.
[0021] FIG. 3 is a perspective end view of the multistage canister filter.
[0022] FIG. 4 is perspective view of a liquid handling system including a pump.
[0023] FIG. 5 is perspective view of a cylindrical screen filter medium.
[0024] FIG. 6 is perspective view of a cylindrical ceramic filter medium with a Zeolite inner coating.
[0025] FIG. 7 is perspective view of a disc shaped ceramic filter medium with a Zeolite inner coating.
[0026] FIG. 8 is a front view of an example of woven material such as a screen filter.
[0027] FIG. 9 is a front view of an example of material woven by ‘Dutch weave’.
[0028] FIG. 10 is front view of an example of material woven by ‘double Dutch weave’.
[0029] FIG. 11 is a cross-sectional view of another embodiment of the multistage filter.
[0030] FIG. 12 is a top view of a linear multistage cylindrical filter.
[0031] FIG. 13 is a top view of selected inner components linear multistage cylindrical filter.
[0032] FIG. 14 is a top view of other selected inner components linear multistage cylindrical filter.
[0033] FIG. 15 is a top view of other selected inner components linear multistage cylindrical filter.
[0034] FIG. 16 is a bottom view of the linear multistage cylindrical filter.
[0035] FIG. 17 is a front view of a screw on filter housing and a filter element.
[0036] FIG. 18 is a front view of a filter housing installed.
[0037] FIG. 19 is a front view of a base for receiving and holding a filter element and a screw on filter housing.
[0038] FIG. 20 is a cylindrical filter with an inlet port at one end and an outlet port at the other.
[0039] FIG. 21 is a group of disc shaped filter media portions aligned as if in a cylindrical housing.
[0040] FIG. 22 is a group of cylindrical, spherical, or disc shaped activated charcoal pellets coated with a selected oxide.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0041] In accordance with the present invention, there is provided a multistage filter for removing contaminants from selected liquids such as fuels and oils. The multistage filter 10 shown in FIG. 3 is cylindrical with a sealed end 9 and a ported end 8 including multiple inlet ports 30 near the outer edges and one outlet port 32 in the center of ported end 8 . The ported end 8 includes an outer O-ring or flat ring 34 and an inner O-ring or flat ring 36 . The ported end 8 of the multistage filter 10 is held firmly against the flat mating surface 56 of a liquid handling unit 50 which includes a pump. The liquid handling unit 50 includes and at least one outlet port 54 and a central inlet port 52 . The O-rings 34 and 36 are thus held tightly against the flat mating surface 56 and form a sealed connection between the filter 10 and the liquid handling unit 50 . The filter 10 is situated against the mating surface so that the outlet port or ports 54 of the liquid handling unit 50 are fluidly connected between O-ring 34 and O-ring 36 and therefore, liquid pumped out of outlet ports 52 would be forced through the inlet ports 30 of filter 10 . It follows then that the inlet port 52 of liquid handling unit 50 receives liquid from the outlet port 32 of filter 10 .
[0042] FIG. 1 shows a cross-sectional view of filter 10 which includes several concentric cylindrical stages. The area 13 between the outer shell 12 and the first stage 14 of filter 10 is the area into which the inlet ports 30 feed liquid under pressure from the pump in liquid handling unit 50 .
[0043] It is understood that the filter 10 is cylindrical and contains concentric cylindrical filter stages of various selected filtering capabilities. It is further understood that all of the concentric cylindrical stages are tightly held against or are firmly and sealingly connected to the ported end 8 and the sealed end 9 of the filter 10 so that no amount of fluid may leak past any one stage of the filter. The first stage includes a screen 14 which catches contaminants of a selected size and passes everything which is smaller. The second stage is a cylindrical filter material 16 which catches contaminants of a next smaller selected size and passes everything which is yet smaller. The third stage 18 is a second cylindrical filter material which will catch contaminants of a next smaller selected size which are small enough to get through the first stage 14 and the second stage 16 but will pass contaminants which are yet smaller in size. The fourth stage 20 is a third cylindrical filter material which will catch contaminants of yet a next smaller selected size which are small enough to get through the first stage 14 , the second stage 16 and the third stage 18 , but will pass contaminants which are yet smaller in size. The final stage 22 is a cylindrical ceramic finer sized to catch contaminants of yet a next smaller selected size which are small enough to get through the first stage 14 , the second stage 16 , the third stage 18 , and the fourth stage 20 , but will pass contaminants which are yet smaller in size.
[0044] It is therefore understood that filter 10 contains multiple stages of varying filtering capabilities and that the first stage catches large sized contaminants and each subsequent stage catches contaminants of a next smaller size. This configuration is the most efficient configuration of filter elements. If the order of the elements was reversed with the first element catching everything including the smallest sized contaminants, no contaminants would ever proceed to the next stages and more importantly, the first stage would become clogged quickly.
[0045] The following is a list of various filter materials with varying filtering capabilities described in terms of the size of particles which will be trapped by the material given in microns or millions of a meter:
List of Filter Media
[0000]
1 Envirostran poly flow material 40 to 60 micron used—beginning FST-26, 63, RF-6, 4, & 8
2 Envirostran poly flow material 15 to 25 micron used—middle RF-8
3 Envirostran poly flow material 5 to 10 micron used before ceramics FST-26, 63, RF-6, 4, & 8
4 Poly flow material 8 micron
5 Poly flow material 5 micron
6 Matt finish combination poly flow material with weave design 8 to 10 micron
7 Matt finish weave combination poly flow material with weave design 2 to 5 micron
8 SS, copper, aluminum, or iron pads used to remove particulate, sulfur, and other unwanted chemicals
9 SS wire cloth 30 micron single weave, or can be double dutch weave
10 SS wire cloth 10 micron single weave, or can be double dutch weave
11 Double weave, matt finish poly flow material 8 micron
12 Ceramics from 2 to 15 microns
13 Metallic screens 40 to 100 microns
14 Zeolite coating 1 micron (captures water)
15 Film membranes filtering to the molecular level
[0061] Filtering coatings other than Zeolite include cationic coatings but do not include catalytic coatings. Film membranes are used as filter media. Ultrafiltration is a variety of membrane filtration in which hydrostatic pressure forces a liquid against a semipermeable membrane. Suspended solids and solutes of high molecular weight are retained, while water and low molecular weight solutes pass through the membrane. This separation process is used in industry and research for purifying and concentrating macromolecular (10 3 -10 6 Daltons or unified atomic mass units) solutions, especially protein solutions. Ultrafiltration is not fundamentally different from microfiltration except in terms of the size of the molecules it retains. Microfiltration is a membrane technical filtration process which removes contaminants from a fluid (liquid & gas) by passage through a microporous membrane. A typical microfiltration membrane pore size range is 0.1 to 10 micrometres (μm). Microfiltration is fundamentally different from reverse osmosis and nanofiltration because those systems use pressure as a means of forcing water to go from low pressure to high pressure. Microfiltration can use a pressurized system but it does not need to include pressure.
[0062] Numbers 9 and 10 in the above list refer to a ‘double dutch’ weave. A dutch weave, shown in FIG. 9 , is a wire mesh or filter cloth with warp wires larger than the weft wires. (Warp refers to the vertical wires 42 and weft refers to the horizontal wires 44 in the mesh as shown in FIG. 8 which is a plain weave.) As shown in FIG. 9 , warp wires remain straight while adjacent weft wires slightly overlap, resulting in a dense, strong material with small irregular, twisting passages that appear triangular in shape when viewing the material diagonally. Double dutch weave, shown in FIG. 10 , is a dutch weave where the weft wires alternately weave through alternate pairs of warp wires. Dutch weaves have much lower flow rates and much higher particle retention than plain square weaves.
[0063] Preferred embodiments of the present invention include a final stage which is a ceramic element. Certain preferred embodiments include a ceramic filter 40 , as shown in FIG. 6 , which has an inner coating 42 of a material such as Zeolite, which filters even smaller contaminants than the ceramic medium 40 . A Zeolite coating is capable of blocking contaminants, such as droplets of water, down to 1 micron in size. Zeolite in powder form (either man made or natural) it can be coated to the inside or outside of any of the filtration media. This is excellent for removing water droplets at the 1 micron level. One downside is the filter cartridge has to be vacuum sealed until it is installed due to the moisture in the air.
[0064] Preferred embodiments of the multistage filter of the present invention therefore include from two to ten filtering stages or more wherein the filtering stages are concentric cylindrical elements where the outer stages contain filter material which catch larger particles than the next inner stages. An example of such a preferred embodiment includes:
a first stage which is a metallic screen which passes 75 micron contaminants; a second stage which is Envirostran poly flow material which passes 50 micron contaminants; a third stage which is Envirostran poly flow material which passes 10 micron contaminants; a fourth stage which is a matt finish weave combination poly flow material which passes 5 micron contaminants; and a ceramic element which passes 3 micron contaminants.
[0069] Another embodiment of the present invention is a linear filter 70 , shown in FIGS. 11-16 . The shell 72 of the filter body in the figures is cylindrical but may be cubic, rectangular, or ovoid. The stages of the filter 70 are stacked linearly, one above the other rather than concentric cylinders. The flow is in at the top 61 and out the bottom 69 . The first stage is a plastic screen 74 with nine apertures 75 . The second stage is a metallic screen 76 of 100 micron mesh. The third stage is a Envirostran poly flow material 78 with 60 micron filtering. The fourth stage is a Envirostran poly flow material 80 with 30 micron filtering. The fifth stage is a ceramic disc 82 with 10 micron filtering. An O-ring 84 of Buna N rubber separates the ceramic disc 82 from the sixth stage which is a metallic screen 86 and a bottom cover 88 including an output aperture 90 .
[0070] Typically filters of the present invention include a cylindrical housing with filter elements inside arranged in stages or layers and wherein the fluid or gas to be filtered enters through an input port and exits through an output port. The layers are arranged in order so that the larger sized contaminants are blocked in the first encountered layers and progressively smaller contaminants are filtered in subsequent layers as the fluid or gas moves toward the output port. Input and output ports are located either on the filter housing ends as in FIG. 20 or on the filter housing side as in FIGS. 18 and 19 . For example, the filter housing 62 in FIGS. 17-19 includes a filter element 63 , a screw-on lid 64 , an input port 65 and an output port 66 . Another example shown in FIG. 20 has input 112 on one end and output 114 at the opposite end of the housing 110 .
[0071] The layers or stages of filter elements are shaped and arranged in two different ways. The first arrangement has filter media layers which are cylindrical in shape as seen in FIGS. 1 , 5 , and 6 and are therefore arranged concentrically as shown if FIG. 1 so that the flow of fluid or gas is preferably from the outer cylindrical layer 12 through consecutive cylindrical layers 14 - 22 to the output port 32 . The other preferred arrangement and shape of filter layers as shown in FIGS. 20 and 21 contains disc shaped filter layers 90 - 100 , for example. The number of layers in either arrangement is only limited by the relative sizes and thicknesses of the layers and the size of the filter housing.
[0072] Filter 110 in FIG. 20 contains the layers 90 - 100 in FIG. 21 contain media selected from the list of filter media above or other media. Other examples of filter media are shown in FIGS. 22 and 23 . Cylindrical or pill shaped pellets 120 or spherical pellets 122 include an activated charcoal substrate coated or impregnated with aluminum oxide or copper oxide. These pellets are from one to ten millimeters in length or smaller. Aluminum oxide or copper oxide coated pellets are ideal for trapping sulfur impurities in natural gas or LPG. One embodiment of the present invention is a filter 110 with disc shaped elements 90 through 100 wherein element 90 is filled with aluminum oxide coated pellets 120 or with copper oxide coated pellets 122 .
[0073] The foregoing detailed description is given primarily for clearness of understanding and no unnecessary limitations are to be understood therefrom, for modification will become obvious to those skilled in the art upon reading this disclosure and may be made upon departing from the spirit of the invention and scope of the appended claims. Accordingly, this invention is not intended to be limited by the specific exemplification presented herein above. Rather, what is intended to be covered is within the spirit and scope of the appended claims. | A filter for separating contaminants from fluids. The filter includes stages of differing materials arranged one after another wherein the first stage blocks and captures contaminants of a selected size and passes everything smaller than this selected size. The next stage captures contaminants of a selected size which is smaller than those blocked by the first stage. The subsequent stages capture smaller and smaller contaminants. The layers comprise various materials including stranded meshes, fibrous tissues, metallic screens and ceramic discs and tubes. Some of the ceramic discs and tubes include a downstream coating to capture further contaminants such as water droplets. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to furniture and millwork; and more particularly to a frame and panel or panels assembly which can be easily assembled or disassembled.
2. Description of the Prior Art
It is well known that one segment of the furniture and woodworking industry is concerned with what is generically known as "knock-down"--hereinafter "KD"--products, which is furniture and other woodwork items which can be easily assembled and disassembled so that the work can be shipped in a knock-down or disassembled condition and can be easily assembled by a lay person with limited mechanical ability. KD products for retail sale are usually referred to as "Ready to Assemble"--hereinafter RTA.
RTA furniture uses a wide variety of mechanically based fasteners. These vary in their machining, strength, construction and suitability for a given project. Some are fully exposed to view, some partially.
There are several basic categories of mechanical fasteners for joints needed to make a frame or other type of wood product requiring the joining of two pieces. Five types of fasteners are: a screw, a bolt, a cam, a wedge, and a nail or staple.
Bracket based corner joints have also been used, but these are ordinarily exposed to view and have limited application.
Most KD/RTA hardware after installation and project assembly would be exposed in a greater or lesser degree to view, unsightly and therefore unacceptable for this invention.
Some KD/RTA hardware cannot be disassembled.
In addition to the hardware previously discussed, there is a vast array of KD hardware available to the woodworking industry. Additional types of hardware which might be considered for assembly for this invention are as follows:
1. Hafele/bed fitting cat #271.53.000 single "keyhole" or #273.56.010 double "keyhole"--This product requires that a pocket be machined behind it to accommodate the head of a screw. This screw is the locking member for the horizontal part of the frame which butts to the vertical part of the frame holding the bed fitting. The screw used with the bed fitting does not have a positive stop for depth as does the collard screw used with the "Modular Connecting Fitting". Selby (#1093 & #1094) and Lamp/Sugatsune (S & W) make similar fittings.
2. Selby/bed rail fastener cat #74. Conceptually this product can work; however, as an off the shelf item, it is too long and would therefore not work for narrow rails (horizontal frame member) as the hardware would protrude beyond the width of the rail itself. For larger scale products it would be suitable. Also for high production runs this product could economically be scaled down. The hardware consists of a rectangular plate with two knockouts which receive the hooks mounted at right angles to a second plate. Pockets would have to be cut behind the plate with the knockouts to receive the hooks. A positive stop is integral to the design of the hardware. Lamp/Sugatsune makes a piece of hardware that is conceptually the same (BF-842-S & BF-842-W)
3. Hafele/nylon KD fitting ("dowel fastening") cat#039.40.707--Product consists of a male and female element; both made of nylon. Each section is inserted into a hole drilled into the section of the frame receiving it. It is possible with this hardware to use as many pairs as are needed to join a particular section. Because of the diameter of the hole to be drilled it would be necessary to use this on larger scaled frames making it impractical for a more standard thickness frame of 11/4" or less (for 11/4" thick frame the groove would be 1/2" as would be the tongue; thereby leaving no material for the hardware to be threaded into on the tongue). Selby (#630, 631, 632) and Lamp/Sugatsune (#CF-235) make similar products. This is one of the least desirable options.
4. Hafele/Haas fastener cat #262.48.000 --Comprised of two identical aluminum press-fit components with harpoon-type barbs. Each piece must be glued into position in addition to being press fitted. The hardware has a positive stop.
Joint strength with KD hardware fasteners appears to be somewhat higher than glued joints over time and the members are easily assembled and disassembled.
Prior art frames and panels have also been glued together with the disadvantage that as time passes the glue joint fails and becomes loose.
Prior art, such as that disclosed in U.S. Pat. No. 3,788,378 discloses a modular divider system which utilizes metal frame members which are joined together by top and bottom horizontal frames with interconnecting members mounted on an end surface of each vertical member so that a series of frames forming flush panels can be joined together to form a modular room divider for a modular office system. While this patent does disclose the addition of a fabric by removable means of a complimentary pin and slot device on the faces of the vertical members the fabric is applied as a sleeve to the exterior of the vertical support members. This type of assembly would be completely unsuitable for use in a decorative screen or for any frame assembly requiring the encapsulation of a panel by a surrounding frame. This prior art does not accomplish the goal of having an aesthetically pleasing product consisting of a panel surrounded by a decorative frame. Not only is the frame of this prior art industrial, unfinished metal; most importantly it was meant to be hidden from view and therefore not intended to embody any generally accepted or traditional aesthetic qualities.
When using frame and panel construction there have been two methods of proceeding. One is to glue, clean up and apply a finish to the frame separately and then secure the panel at the back with applied molding which is usually nailed in place. The second method is to completely assemble i.e. glue up, sand and apply a finish to the frame and panel as assembled. In this method the molding is integral on both sides and therefore retains the panel after the frame is glued up.
The use of molding or trim both for decorative purposes and for the utilitarian purpose of retaining panels is commonly used in frame and panel work. The machining and installation of these moldings can become quite problematic, most especially when there are deviations from the straight line. It is well known that frames may have design variations from a rectangular format. For these frames, for example the top rail may have a concave arc formation on the interior of the frame (or other e.g. curved pattern variation, which may be an interior and exterior arc). Ordinarily rabbets would be machined on the back of the frame and would receive the panels after frame assembly and finishing. This method is especially needed when one is using a panel insert which is other than wood (e.g. glass or fabric) and therefore needs to be installed after the frame is finished to keep it from being damaged.
The second method is usually used in higher production work. The frames, having integral molding, and the panels are assembled and joined prior to finishing. The frame with its integral panel is then finished as one piece. This makes things very difficult when using non-wood materials for panels.
There are other considerations. Some problems in manufacturing procedures can arise. One being that the groove or rabbet plowed to receive the panel would usually be machined parallel to i.e. in conformance with, the edge of the curvilinear shape. It would require that the panel insert also be machined to mirror that shape; creating additional machining as opposed to simply cutting a square or rectangular panel shape. To avoid this problem and decrease labor costs the groove plowed for such design configurations could be plowed straight across and therefore would run perpendicular to the other panel receiving element e.g. groove, situated in the stiles. This would only be possible on designs which had top rails wide enough to allow this deep cut. Top rails which were curvilinear on both the outside and inside edges would have to have a panel receiving element e.g. groove, plowed parallel to the inside curve and the panel receiving element e.g. groove would maintain the same depth end for end; therefore the panel receiving element e.g. groove, would be curvilinear instead of straight across. The choice in machining of this top rail groove is a cost and machining set-up consideration.
SUMMARY OF THE INVENTION
It is an object of this invention to produce a completely finished, high quality product of frame and panel construction allowing for separate finishing of the frame and panel; further to have integral molding on both faces of frame regardless of frame design and for both faces of frame to be of equal design and quality and to allow for finishing of frame with no damage to especially non-wood panels such as fabric.
It is further the object of this invention to allow for the possibility for especially small custom shops to economically yaw the size of the frame based on the dimensions of the panel insert to be inserted and to quickly assemble and ship varying size orders without the currently extremely labor intensive and therefore prohibitive methods available to such shops.
A still further object of this invention to provide for an assembly for use in joining two adjacent members which can be easily assembled and disassembled.
Another object of the invention is to provide for an assembly for use in connection with KD/RTA furniture and general woodwork.
Another object of this invention is the provision of an assembly for use in joining two adjacent members so that the two adjacent members will be free of any exposure of hardware whereby no distinction is drawn between an obverse and a reverse side.
Yet another object of the invention is to provide for a method and system for KD/RTA furniture, readily usable in connection with few tools, if any and to provide for furniture which can be readily assembled and disassembled.
In its broadened aspect, the invention is concerned with a fully machined frame--decorative or functional--which can be assembled without the necessity of tools. More specifically, the frame according to the invention can be readily assembled and does not require the addition of separately applied molding strips to retain a panel insert as might be required for a traditionally conceived and machined piece. This alone eliminates assembly and machining procedures which are costly and time consuming.
The most important aspects of the invention are the use of KD hardware along with the use of fully machined, and in most uses, pre-finished frame parts. This permits convenient shipping of frames which heretofore would have required full assembly and therefore the shipment of a much larger article to the end user. This is an issue that greatly impacts shipping costs. It also permits the convenient use of a frame or folding screen in commercial displays so that the screen can be readily assembled without the use of tools at a display site. It permits the convenient changing of panel inserts as display materials change or need to be upgraded. Beyond the convenience offered in shipping and assembly; and alteration potential offered by this invention, it has the added benefit of permitting a frame member to be assembled with all of its decorative molding as integral to the rails and stiles; and not applied after joining of frame parts as is traditionally done. This is most especially useful for curved members. It eliminates the necessity of making separate curved small molded parts which are labor intensive and costly and difficult to produce. It further eliminates the necessity of the use of brads, air nails or screws to secure separate molding and the need to putty same for a fine finish. This feature of integral molding, as opposed to applied, most especially makes this invention useful to the RTA market.
Another feature of the invention is to overcome the problems inherent in some design configurations of frames, which have the concave arc formation i.e. the problems of design, cost and machining associated with this formation.
Another feature of the invention is to overcome the problems inherent in having, especially, a non-wood panel insert e.g. fabric which can be inserted after all wood parts have had their finish applied.
The KD (knock down) hardware used heretofore, to join the frame is a product as shown in the "Hafele" cabinet catalogue (cat #262.47.049 Standard Modular, or 262.47.058 Semi-Permanent Modular, or 262.47.012 Permanent Modular i.e. cannot be disassembled). It is called "modular connecting fitting" and is used in conjunction with a Hospa collared screw. The KD hardware is secured with screws (factory mounted) to the bottom of the panel receiving element e.g. groove machined on the inside edges of the frame. This hardware is placed at the point of the joint i.e. where the horizontal member butts the vertical member of the frame. On the stiles (verticals) are mounted a female portion of the hardware; consisting of a formed strip of metal with a keyhole slot to receive the head of the collared screw. On the ends of the rails (horizontals) are mounted a male KD hardware piece consisting of a screw with a protruding head and integral flange (collared screw).
With the installation of the KD hardware, according to the invention, on the stiles and rails the frame can be assembled by the end user without the use of glue, nails, screws, clamps, screwdrivers, wrenches or pliers. The assembled product appears to the viewer as a traditionally joined decorative frame, and what is important is that the frame presents a finished appearance regardless of whether it is viewed from the obverse or the reverse.
It is therefore another object of the invention to provide a furniture assembly consisting of a frame and panel which can be easily assembled and disassembled without the use of glue.
The invention in its broadest aspects, comprises at least two (side) vertical (stile) frame members and at least two (top and bottom) horizontal (rail) members. Along all interior edges, a panel receiving element e.g. groove is plowed to receive both the connecting hardware and the panel insert; therefore, the exterior rails and stiles forming the perimeter of the frame would have a groove plowed on one side only (the one facing the interior of the frame). The center vertical and horizontal members would have a groove plowed on both edges (since both edges face the interior of the frame).
The frame and panel assembly in accordance with this invention is easily assembled and/or disassembled and can be readily used with fabric, art work, or numerous types of other materials for assemblies of frames and panels. To form a set of two or more frames; with pictures, designs or carvings, for example as panel inserts, the frames are often hinged--but not necessarily so. This configuration is most often used as folding room screens for decorative use. In some instances disassembly may be more difficult depending on the configuration of the assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention may be more clearly understood and readily carried into effect, the same will now be described and explained in connection with the accompanying drawings, in which:
FIG. 1 is a front perspective view of an assembled individual frame having rails and stiles adapted to receive an insert prior to assembly and easily disassembled to change or remove inserts held by the rails and stiles and illustrating one center rail connected between the two vertical stiles.
FIG. 2 is a longitudinal sectional view taken along line 2--2 of FIG. 1 or line 2--2 of FIG. 5 illustrating the rails in section spaced from each and appropriately spaced to hold inserts shown in dot-dashed outline;
FIG. 3 is a transverse sectional view taken along line 3--3 of FIG. 1 showing a pair of spaced stiles with the inserts shown in dot-dashed outline;
FIG. 4 is a view showing the frame of FIG. 1 disassembled with the horizontal rails and the vertical stiles spaced from each other and illustrating the connectors on the parts to be joined;
FIG. 5 is another frame embodiment according to the invention which is a modification to the frame of FIG. 1 and includes a pair of rails--top and bottom, and center mullions (interior members of a frame separating the panels from each other) both vertical and horizontal. A variation of FIG. 5 would be to have both top and bottom rails run through or to have the center mullion run through;
FIG. 6 is a transverse section taken along line 6--6 of FIG. 5 and illustrating the common center mullion spaced between the two outer stiles with inserts shown in dot-dashed outline;
FIG. 7 is a sectional view taken along line 7--7 of FIG. 4 and showing a stile and rail spaced from each other which are to be connected together.
FIG. 8 is a vertical sectional view taken along line 8--8 of FIG. 7 of a center rail (mullion) and a stile separated from each other and illustrating the connecting elements in their disconnected condition;
FIG. 9 is a vertical sectional view similar to that of FIG. 8 showing a stile and a center rail (mullion) connected to each other and taken along line 9--9 of FIG. 10;
FIG. 10 is a sectional view taken along line 10--10 of FIG. 9 or a sectional view taken along line 10--10 of FIG. 1,5,12 or 13 illustrating another view of the stile and rail as connected to each other;
FIG. 11 is a perspective view of the prior art connecting elements in their spaced disassembled condition;
FIG. 12 is a front view of another embodiment of the frame which includes two outer vertical stiles and a center mullion with a bottom rail extending across and below the center mullion and joined to the two outer stiles at their inside edges, the center mullion being joined to the bottom rail, and two upper curved rails joined to the two outer stiles at their inside edges and connected with the center mullion. A variation of FIG. 12 would be for the top curved rail to run through end for end and for the center mullion to butt to it underneath and;
FIG. 13 is another modification of a frame in which there is a single curved upper rail, two outer stiles and a center mullion spaced between the two outer stiles.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now more particularly to the drawings, and in particular to FIGS. 1 to 4 of the accompanying drawings; frame assembly 10 generally includes a pair of oppositely disposed vertical side stiles 12, 14 and two horizontal rails 16, 18 and a center divider or mullion 20.
Each of the rails and stiles is provided with a panel receiving portion e.g. groove 22 to receive a panel 24 shown in dashed outline. The outer portions of each panel receiving portion e.g. groove is provided with arcuate surface (this design varies) portions 26, 28 and form corners 30 which are coped and therefore provide a uniformly merging overlap and an outer flush surface 32, excepting the chamfer recess at the joinder of the rails and stiles along the faces 34, 36.
In the FIGS. 1-4 embodiments, one starts with two stiles 12 and 14 and the three horizontal rails although only two horizontal rails are required, but for purposes of discussion, horizontal rails 16, 18 and 20 will be discussed. Each of the stiles and rails include a panel receiving element, e.g. a groove 22, and the central rail (mullion) includes two panel receiving elements, e.g. grooves 22 in order to receive an insert or panel 24 on each side thereof. Reference is now made to FIGS. 7-11 in order to explain the connector. As shown in FIGS. 7-10, each connector assembly 40 as shown in FIG. 11 includes a first element 42 and a second element 44. Element 42 is receivable within panel receiving portion, e.g. groove 22 and includes a pair of tabs 46, 48 having screw openings 50 for connection to the bottom or flat surface 22B of panel receiving portion e.g. groove, 22 and each of the tabs 46, and 48 includes a flat surface 46F and 48F which is placed against flat surface 22B and screwed into the stile by means of screws 52 which pass through the openings 50 and provide a tight connection with the surface material beneath the base of 22B. Connection element 44 includes a threaded screw member 54 having a screw head 56 and a collar 58 which rests against the base member 22TB of the rail.
Connector element 40 in addition to the tabs 46 and 48 includes a substantially U-shaped member 60 having a base portion 62 and arms 64 and 66 joined and formed continuously with tabs 46, and 48. Tab 46 of base member 62, includes an opening 460 which has an opening wide enough to receive screw head 56 but insufficiently wide to receive collar 58.
Tab 64 has the opening 640 which is connected with opening 460 and extends along U-shaped arm 64 and connects with opening 620 in the base 62 of U-shaped member 60. Opening 620 has a diameter which is wide enough to receive screw head 56 with shaft 70 between screw head 56 and collar 58 slidable within opening 620. Collar 58 acts as a stop so that when screw 44 is secured into its position in the rail it allows the dimension between the underside of collar 58 and the underside of screw head 56 to remain constant. This allows the manufacturer to calibrate and set other dimensions so as to establish and set up an appropriate tension to hold the rail and stile in a given position against one another. In addition, the thickness surrounding the opening of 620 increases from the portion near entry point 62A to the bottom i.e. far end 62B so that by the time shaft 70 moves down to the base at 62C, there is a tight fit between base 62 and screw head 56 caused by a wedging action. It is the tension between the back of screw head 56 and the underside of 64, in conjunction with correct machining of frame members that holds the pieces of the frame in position one against the other. The connection can be made either by the use of hand force or a rubber mallet to tap one member into the other member.
As best seen in FIG. 10, an example of connector assembly 40 is shown with second connector element 44 joined with rail 20 and first connector element 42 joined with stile 12. As best seen in FIG. 7, stile 12 and rail 20 are disconnected from each other.
Referring now to FIGS. 7-9, connector assembly 40 is secured within the panel receiving element e.g. groove 22, and panel receiving element e.g. groove 22 includes upstanding sides or legs 22L each having a leading end 22LB. Rail 20 which is machined (i.e. coped) to compliment the machining (i.e. molding pattern) of stile 12 will fit with and onto the outer section of legs 22L. The end of rail 20 includes a trapezoidal configuration formed by the slope of the inner sides of legs 22TS. The substantial U-shaped inner trapezoidal configuration receives the legs 22L of 22 with the leading end 22LB of the legs 22L being held against the base 22TB when connectors 42 and 44 are connected together. The spacing between screw head 56 and collar 58 is longer than the thickness 62B. The locking engagement is maintained by the molding pattern of 22L being firmly held against the opposite, but complimentary molding pattern of 22TS, when the connectors 42 and 44 are engaged and by the tension created by the wedging action created by the back of screw head 58 pulling behind surface 62 of connector element 40. The surface portion of trapezoidal sides 22TS and the outer surface portion of 22L are always complementary to each other and could be any pattern chosen.
While in the present discussion of an explanation of various embodiments, the stiles have been shown with first connector element or locking element 42 and the rails with second connector or locking element 44, it will be evident from the further explanation of other embodiments that these connectors can be interchanged between placement on rail and stile.
Reference is now made to FIGS. 5 and 6 which show another embodiment of a frame according to the invention and this frame includes four panels 24 with stiles 12 and 14, rails 16 and 118. A center mullion 112 (a mullion is a linear member separating the panels and within the perimeter created by the rails and stiles) is provided which includes two panel receiving portions, e.g. grooves (one per edge) and two short rails (or mullions) 20 which overlies two additional panels 24. It will be evident that the frame can be increased by increasing any set of given members.
Stile 12 is connected to rail 16 at connection junction 12-16 by means of connector assembly 40 as discussed in FIGS. 7-11. In a similar manner, connector assembly 40 joins rail 16 to mullion 112 at both connections on both sides on mullion 112. The connection at the other end between rail 16 and stile 14 is the same type of connection. With respect to rails 20 and the joinder to mullion 112, the connection at connectors 112-20 are the same as that shown in FIGS. 7-11 and, the connection at rail 16 and rail 20 is also of the same type. The center mullion 112 is held in place by means of rails 16 and 20 which in turn are held in place by outer stiles 12 and 14. The upper rail 118 joins mullion 112 by 112 sliding into position by means of hardware connector assembly 40. The connection between stile 12 and top rail 118 and stile 14 and top rail 118 is also the same as that shown in FIGS. 7-11. The order of assembly is thus: 112 is joined to top rail 118, 12 and 14 are joined to 118, two panels 24 are slid into position, rails 20 are slid into position, two more panels 24 are positioned and finally rails 16 are slid into position locking all members into position. This completes the frame with four panels divided by mullions at the interior.
Reference is now made to FIGS. 12-13 which show two different types of embodiments for arranging rails and stiles. These figures clearly demonstrate that vertical stiles and horizontal rails can have curvature imparted thereto or can be non-linear depending on the configuration desired, and while the stiles are shown as straight in these figures, it is possible to have curved rails and curved stiles, with the proviso that the panels must be insertable into the rails and stiles so that an appropriate and ultimately locking outer frame is achieved.
In FIG. 12, stiles 12, 14 and mullion 112a are shown as straight. The upper rails 118a are shown curved. In the FIG. 12 embodiment, the lower rail 16a is first connected with the stiles 12, 14 and mullion 112a. Then the panel inserts are placed into the individual areas and upper rails 118a are connected at the side with stiles 12 and 14 and mullion 112a.
Referring now to FIG. 13 which shows another modification and shows upper rail 118b as a single curved rail connected with stiles 12 and 14. This configuration uses a center mullion 112b which is connected to the top rail 118b with a dowel only. The bottom rail 16b is connected by its ends to stiles 12 and 14 and is joined to the mullion 112b with hardware connector assembly 40. The order of assembly is thus, bottom rail 16b is connected to side stiles 12 and 14, slide mullion 112b into place, slip panels 24 into openings created for them by frame, slide top rail 118b into place on stiles 12 and 14 with hardware connector assembly 40 at each end while positioning hole in top rail 118b onto dowel positioned in top of mullion 112b. This dowel holds the mullion in place and prevents lateral movement when top rail 118b is moved into position it locks entire assembly together.
DESCRIPTION OF OPERATION AND UTILITY
Strips of wood or other materials which are to be utilized to form an individual frame or any configuration thereof, be it single or multiple in formation can be used to carry out the invention. A typical use would be in the configuration of a folding room screen, finished on both sides as assembled, a picture frame ready for hanging, a trade show display which is similar to a folding room screen, a frame and panel assembly for case goods sides, etc., and a frame and panel wainscot or full room paneling. These uses are especially useful in RTA marketing where amateurs and home users do not have the professional equipment or expertise to join and clamp such configurations. Each section, or independent unit is formed by the joining of members, rails (horizontal members), and stiles (vertical members) usually at ninety degrees to one another to form a square or rectangle. Upon assembly, be the style traditional or contemporary, no means of assembly are visible. The method of assembly is by sliding one male hardware member into an opposite female hardware member by pressure only. No tools, such as screw drivers or wrenches, are required. (This is assuming factory mounting of the hardware.) A hammer or mallet may be required to tap the joints flush if the members are machined to very tight tolerances. In high production it would be possible to machine to careful tolerances which would probably make the use of a mallet unnecessary. The vertical side members or stiles which are the same size, most often run the length of the frame (as opposed to stopping atop the bottom rail or under the top rail). The top, bottom and center cross-pieces or rails are of the same length; but may vary in height (i.e. the short dimension); and as is traditional in most layouts, butt to the stiles at their inside edge. All inside edges of both rails and stiles are plowed with a panel receiving portion e.g. groove, running the length of the member. It is inside this panel receiving portion e.g. groove that the hardware is secured for assembly of the frame. Again, as is traditional, the inside edges of both faces are molded with a sticking pattern. The rails are coped (machined so as to configure the abutting molding profile) to the stiles on both faces i.e. front and back. A panel of any material, such as wood, fabric or glass is inserted into the plowed groove as the frame is being assembled, and the insert is locked in place when the fourth or last member forming the square or rectangular opening for the insert is pressed into position. The integral molding on both sides of the frame is what retains the panel. Depending upon the joining hardware chosen, it is possible to disassemble the frame so as to change the panel insert. This is possible when particular KD hardware used for assembly also allows disassembly of the joint. Some KD hardware as noted heretofore, cannot be disassembled, and it is a feature of the invention to provide for ease of assembly as well as disassembly.
In addition to those technical issues already discussed there is another which needs to be considered. This involves the natural shrinkage and expansion of wood. When one joins two pieces of wood together by gluing them, this natural movement is minimized as they relate to each other; however, it is not the intention of this invention to use glue. Therefore the natural and probably uneven movement of wood pieces placed one next to the other could create troublesome and aesthetically unacceptable problems for a finished product. To alleviate this issue a chamfer would be machined on the ends of the faces of the rails where they join the stiles. The use of the chamfer would eliminate this problem and become integral to the design.
Further a length of wood being joined at each end by the same connector assembly 40 can be secured to the bottom of the frame to act as a foot or glide for the frame assembly.
While there has been shown what is considered to be the preferred embodiments of the invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the scope of the invention. | A frame assembly of the knock-down type in which the component parts can be shipped or transported in a knock-down condition and readily constructed with a minimum of tools or no tools, and disassembled when desired. The frame assembly includes at least one pair of spaced vertical stiles and at least one pair of horizontal rails substantially orthogonal thereto, and associated connecting elements for connecting the stiles and rails, one of the connecting elements being joined with a stile at a corner connection thereof and another of the connecting elements being joined with a rail at a corner connection thereof so that a pair of the associated connecting elements joins one of the stiles to one of the rails, and all of the stiles and rails as appropriate are joined to each other. | 4 |
This application claims the benefit under 35 USC §119 to U.S. provisional patent application 61/153,660 filed 19 Feb. 2009.
FIELD OF THE INVENTION
The present invention relates to an improved purification process for the purification of daptomycin represented by the chemical name N-decanoyl-L-tryptophyl-D-asparaginyl-L-aspartyl-L-threonylglycyl-L-ornithyl-L-aspartyl-D-alanyl-L-aspartylglycyl-D-seryl-threo-3-methyl-L-glutamyl-3-anthraniloyl-L-alanine ε1-lactone. Daptomycin can be presented by the formula I:
BACKGROUND
Daptomycin is a lipopeptide antibiotic with activity against gram-positive organisms. Daptomycin is produced by fermentation of Strepromyces roseosporus and then purification of the fermentation broth. The mechanism of action for daptomycin is that it binds to bacterial membranes and causes a rapid depolarization of the membrane potential. This loss of membrane potential causes inhibition of protein, DNA and RNA synthesis, resulting in bacterial cell death. Daptomycin is approved for complicated skin and skin structure infections (cSSSI) and Staphylococcus aureus bloodstream infections (bacteraemia). Daptomycin is marketed by Cubist Pharmaceuticals under the trademark CUBICIN®.
Daptomycin was first described in the mid 1980's in several patents and journals; U.S. Pat. No. 4,537,717 and Debono M. et al, Journal of Antibiotics, 1986, Vol. XL, No 6, 761-777. Since then there have been several publications regarding improved fermentation processes and purification processes.
In U.S. Pat. No. 4,885,243 an improved fermentation process for making daptomycin is described. This method describes the feeding of decanoic fatty acid or ester or salts thereof to a fermentation broth of Strepromyces roseosporus . During fermentation, the decanoic fatty acid will be inserted to the molecule to form the decanoic side chain of daptomycin.
In the prior art, several purification processes for purifying daptomycin has been described. U.S. Pat. No. 4,874,843 describes a method for purifying daptomycin in which the fermentation broth was filtered and added to a chromatographic column containing Diaion® HP-20 styrene-divinylbenzene resin for hydrophobic compounds. After elution, the semipurified daptomycin was passed through a column containing Diaion® HP-20ss resin and then added to another column containing Diaion® HP-20 resin, a directly polymerized small particle size version of HP-20. In addition to these steps, attempts to increase the purity with several additional chromatographic steps without any success are described. The '843 patent further teach that by using a non-functional resin and an aqueous solution and including a step where water are physically removed and then rewet the resin with a polar organic solvent, the purity of the product is increased from 80% to 93%. This process is time consuming and not very well suitable for industrial production.
The U.S. RE 39,071 patent describes the two major impurities found in the production of daptomycin, the anhydro-daptomycin and the beta-isomer of daptomycin. The U.S. RE 39,071 further states that by using the method described in example 1-3 you will have a daptomycin product comprising less than 6% of the two mentioned impurities. Example 3 describes a method where intermediate quality of daptomycin is further purified in a method comprising four chromatographic steps and additional desalting, concentration and freeze drying steps. In the chromatographic steps acetonitrile is used for washing and elution and in addition you have to perform the method with chilled solutions and in a chilled room.
U.S. Pat. No. 6,696,412 patent disclose a method for purifying daptomycin by utilizing an anion exchange chromatography step where a modified buffer is used for elution and by utilizing a microfiltration step where daptomycin forms micelles. There are several methods described in this patent that is a combination of the two steps mentioned above in combination with other purification steps familiar to the person skilled in the art. The highly purified daptomycin product is defined in the patent to be daptomycin with a purity level of 95-97%.
SUMMARY OF THE INVENTION
The present invention provides for an improved purification method for purifying daptomycin that result in a product with a purity of at least 95%. The described method is simpler than those methods described in the prior art and as described below it renders superfluous the use of modified buffers and avoids the use of acetonitrile which is a benefit to the environment.
The method according to the invention utilizes the steps of anion exchange chromatography and reverse phase chromatography. In addition, normal filtration steps and lyophilisation of the final product may be performed.
According to one embodiment, the monovalent salt solution used as elution buffer in the anion exchange chromatographic steps is a solution of sodium chloride in water.
The elution buffer of the reverse phase chromatographic step b) of the present invention is aqueous alcohol. Preferably, the aqueous alcohol is aqueous ethanol. According to one embodiment of the present invention, daptomycin is eluted from the reverse phase chromatographic step using an elution buffer comprising 40-70% ethanol in water.
The present invention can be illustrated by the steps given in the reaction scheme 1.
The present invention results in a daptomycin product with a total purity of 95% or more. The amount of the anhydro-daptomycin varies between 0.5-1.5% and the amount of the beta-isomer is less than 0.5%.
The method according to this invention provides a purification method that is simpler than methods known in the art with respect to the buffers and steps used, it avoids the use of solvents that are toxic to the environment. In addition, it results in a very good separation and low levels of the two most important impurities; anhydro-daptomycin and the beta-isomer of daptomycin. The method according to the invention gives a simple purification process while providing a product that is at least as pure as products described in the prior art.
DETAILED DESCRIPTION OF THE INVENTION
The starting material of the process according to the present invention can be made by the method described in U.S. Pat. No. 4,885,243 where the fatty acid to be fed is decanoic acid.
According to the present invention, daptomycin is purified by the use of a first anion chromatography step, and a following second reverse phase chromatography step.
The fermentation broth used as a starting material of the present invention may be pre-treated before said chromatography steps to remove large particles and biomass. As a pre-treatment method, the fermentation broth used as a starting material of the present invention may be passed through one or more clarification steps. Various useful clarification steps are known to the person skill in the art. Non-limiting examples of clarification steps useful to pre-treat the fermentation broth according to the present invention is reverse osmosis, centrifugation, ultrafiltration, microfiltration, nanofiltration, and diafiltration. Even an anion exchange step with a highly porous resin is possible to utilize for clarification.
It is to be understood that various combination of clarification methods well known to the skilled person may be used according to the present invention to pre-treat the fermentation broth before further purification of daptomycin by anion change chromatography and reverse phase chromatography.
The clarified fermentation broth is added to an anion exchange column. Both strong anion exchanger resins such as Capto Q (high-flow agrose strong anion exchange resin produced by GE Healthcare), Q Sepharose™ XL (highly cross-linked agarose ion exchange resin produced by GE Healthcare), Q Sepharose™ FF (highly cross-linked agarose fast flow ion exchange resin produced by GE Healthcare), Source™ 15 Q (polystyrene/divinylbenzene anion exchange resin produced by GE Healthcare), Source™ 30 Q Q (polystyrene/divinylbenzene anion exchange resin produced by GE Healthcare)or Macroprep® High Q (rigid methacrylate strong anion exchange resin produced by Bio-Rad), or equivalents and also weak anion exchanger resins, such as the commercial available resins DEAE Sepharose™ FF (cross-linked agarose ion exchange resin produced by GE Healthcare), ANX Sepharose™ FF (crosslinked agarose ion exchange resin produced by GE Healthcare), Source™ 15 Q may be used according to the present invention. The preferred resin is a highly cross-linked agarose resin with dextran surface extender, like the commercial available resin Capto Q. After loading of the clarified solution, the column is washed with water.
The elution buffer of the anion exchange chromatography step a) of the present method is a monovalent salt solution. Said monovalent salt may e.g. be a chloride salt such as NaCl or KCl. Other monovalent salts may also be used such as monovalent salts of acetate, such as sodium acetate.
According to one embodiment, daptomycin may be eluted from the column with a NaCl gradient in water with the gradient going from 0.1 M NaCl to 1.5M NaCl, preferably going from 0.2M NaCl to 1.0M NaCl.
The semi-purified daptomycin is then added to a reversed phase column. The preferred reverse phase resin is a monosized, porous resin made of polystyrene and divinyl benzene, like the commercial available resin Source™ RPC 30 (polystyrene/divinyl benzene resin produced by GE Healthcare, Sepabeads® SP20ss (small particle size styrenic resin), Diaion® HP20ss or equivalent polystyrene based resin types. After the daptomycin solution has been applied the column, the column is washed with water containing 15% of alcohol, such as 15% ethanol.
The daptomycin may be eluted with an aqueous alcohol, e.g. a C1-C3 alkyl alcohol, such as methanol, ethanol or isopropanol. According to one embodiment of the present invention, daptomycin is eluted from a reversed phase column using ethanol as the eluting solvent.
Daptomycin is according to one embodiment eluted from the reverse phase column by a gradient of ethanol in water. The gradient is from 5-80% ethanol and preferably from 40% -70% of ethanol.
In one preferred embodiment of the invention there is an additional step of reverse phase chromatography. A preferred embodiment of the invention is to run the two reverse phase columns on different pH to improve the purity of the product. In one preferred embodiment the first column is run at neutral pH and the second column is run at acidic pH. It is not essential which order the two reverse phase chromatography steps are run in respect of pH. The first column may be run at acidic pH and the second at neutral pH or vice versa.
According to one embodiment of the invention, the first reverse phase chromatography column is eluted at pH 6.5-8.5, preferably at pH 7.5-8.0. According to another embodiment of the invention, the second reverse phase chromatography column is eluted at pH 2.5-3.5, preferable at pH 3.0-3.1.
The column to be used in the reverse phase chromatography step in the method according to the present invention may be a styrene based resin such as the commercial available resin Source™ 30RPC. Other equivalent reverse phase chromatography resins, such as Sepabeads® SP20ss, Diaion® HP20ss or equivalent polystyrene based resin types known to the skilled person may also be used.
The purified daptomycin is then filtered and lyophilized under standard conditions. The final purified daptomycin has a purity of at least 95%.
EXPERIMENTAL
Example 1
After clarification the partly purified daptomycin solution was loaded on an anion exchange column. The starting material was clarified by diafiltration.
Purification on Ion Exchange Chromatography:
Diafiltrated daptomycin was loaded onto an anion exchanger column, Capto Q resin.
Buffers were prepared in separate tanks with the following composition:
Buffer 1: DI-water Buffer 2: 0.2 M NaCl Buffer 3: 0.4 M NaCl Buffer 4: 1.0 M NaCl
The starting solution was adjusted to pH 6-8 with a diluted NaOH prior to loading. The daptomycin was bound to the resin at a maximum capacity of 20 g/L resin. After binding to the resin, fermentation related impurities were washed out initially with buffer 1 then followed by buffer 2.
Elution and recovery of daptomycin was conducted isocratic with buffer 3. After elution the column was stripped with buffer 4 to remove any remaining daptomycin or strong binding impurities.
The daptomycin was collected based on a volume app. 5-10 BV
Reverse Phase Chromatography I (RPC I):
The daptomycin was purified by HPLC using a styrene based Source™ 30RPC resin
Buffers for the step were prepared in separate tanks:
Buffer 1: DI-water Buffer 2: 12-16% ethanol Buffer 3: 55-65% ethanol
Daptomycin was purified at neutral pH (pH 7.5-8.0). Initially the column was equilibrated with buffer 1. The daptomycin was loaded onto the column (maximum loading degree <30 g/L resin) before less hydrophobic impurities were washed out (mainly degradation products) using buffer 2.
Daptomycin was then recovered by gradient elution 15 to 60% ethanol (gradient mixing of buffer 1 to 2) over 12-16 BV. The daptomycin was collected based on UV signal.
Reverse Phase Chromatography II:
Based on purity, fractions were collected and pooled from the first reverse phase chromatography step (RPC I) and pH was adjusted to pH 3.0-3.1 with acetic acid under fast stirring in order to prevent precipitation of the daptomycin in the tank.
Buffers for this step were prepared in separate tanks:
Buffer 1: DI-water, pH 3.0-3.1 was adjusted with acetic acid Buffer 2: 30-35% ethanol, pH 3.0-3.1 was adjusted with acetic acid Buffer 3: 65-75% ethanol, pH 3.0-3.1 was adjusted with acetic acid
pH adjusted daptomycin solution was loaded onto the column (maximum loading degree <30 g/L resin) and less hydrophobic impurities were washed out with buffer 1. Elution and recovery of the daptomycin was conducted by running an ethanol gradient from 35% to 70% mixing buffer 2 and 3 over 8-12 BV.
The daptomycin was collected based on UV-signal.
Example 2
To clarify the fermentation broth, several clarification methods was used. Firstly, the fermentation broth was centrifuged in order to remove large particles and biomass. The pH in the fermentation broth was 6.4 and the dry material (DM) was about 6-7%. After centrifugation the supernatant contained only 3% DM. The supernatant was then further pre-filtrated through a 25-100 μm filter in order to remove particles larger than 25-100 μm.
The centrifuged and pre-filtered solution was then ultrafiltrated through a Pellicon® 2, 500 kD (Millipore) filter to remove large molecules. After ultrafiltration the solution was up-concentrated by nanofiltration. The filter used was DL-series, 350D (GE Osmonics). The retentate contained 5 g/l of daptomycin and had a pH of 6.
The retentate was further purified by an anion exchange chromatography column according to the present invention. The resin used was Capto Q (90 μm) from GE Healthcare. The pH in the retentate was adjusted to pH 6 with NaOH if needed before it was loaded on to the column. After the retentate was loaded on to the column, the column was washed with water and the daptomycin was eluted with a NaCl step gradient. The elution solutions contained 0.2M, 0.4M and 1.0M NaCl in water. The pooled fractions from the anion exchange column contained about 2.5 g/l of daptomycin.
The pooled fractions from the anion exchange column was then loaded into the first reverse phase chromatography (RPC I). The resin used was Source™ 30RPC (30 μm) from GE Healthcare. After loading the column was washed with water and eluted with a gradient of 20-50% ethanol at pH 7-8. The fractionation pool from this step contained about 6 g/l of daptomycin.
This fractionation pool was further loaded into a second reverse phase column with the same resin. After loading the daptomycin solution from the previous reversed phase column, the column was washed with water and daptomycin was eluted with a gradient of 20-50% ethanol at pH 3.0. The fractionation pool from this step contains about 8 g/l of daptomycin.
The daptomycin solution was then processed through a nanofiltration step with a DL-series, 350D membrane from GE Osmonics.
After nanofiltration the daptomycin solution was lyophilized using standard conditions.
The purity of the final product is in the range of 95-97%. | The present invention relates to a process for purifying lipopeptides. More particular, the invention provides an improved method for purifying daptomycin. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a division of, and claims priority to, commonly-owned, co-pending U.S. application Ser. No. 12/189,639, filed on Aug. 11, 2008, which application is incorporated by reference herein as if set forth in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED-RESEARCH OR DEVELOPMENT
[0002] None.
INCORPORATION BY REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC
[0003] None.
FIELD OF THE INVENTION
[0004] The invention disclosed broadly relates to the field of integrated circuits, and more particularly relates to a Self-aligned SOI Schottky Body Tie Employing Sidewall Silicidation.
BACKGROUND OF THE INVENTION
[0005] In silicon-on-insulator (SOI) technologies, there are many cases where electrical contact to the normally floating body region is highly desirable. Among these cases include the mitigation of history effects in SOI and the enablement of low leakage SOI devices and/or high voltage SOI devices. There are many known solutions in the known art. Almost all of these solutions typically have substantial density and parasitic penalties and many are not self-aligned. Many of the solutions also consume a portion of the device's electrical width.
[0006] The formation of a dual-sided Schottky body tie was first described by Sleight & Misty (IEEE International Electron Devices Meeting 1997). In Sleight & Mistry's work, the dual-sided Schottky body tie was formed by intentionally omitting dopant from a portion of the diffusion region. While effective, this approach results in a loss of device electrical width as well as poor gate control from low gate doping in the regions.
[0007] J. Cai et al. (IEEE International Electron Devices Meeting 2007) describe using a Schottky body contact where the diffusion implants are angled in a manner to expose the source silicide to the body. This approach has drawbacks with the masking required and groundrule considerations on the angle that may be employed.
[0008] Therefore, a need exists for an improved SOI technology to address the foregoing shortcomings.
SUMMARY OF THE INVENTION
[0009] Briefly, according to an embodiment of the invention, a structure is used to form a dual sided Schottky body tied SOI transistor device. The structure is self- aligned, has no detrimental parasitics that can occur from the terminals, does not consume any of the device's electrical width, and does not require masking or special implants. The transistor includes the following: a source region with a silicide layer disposed on its top surface; a drain region with a silicide layer disposed on its top surface; a channel with a diffusion region formed between the source and drain regions, and a silicide layer extending into the diffusion region; a gate region disposed above the diffusion region; a metal deposition region that covers the sidewalls and top of the diffusion region; and a gate oxide layer disposed between the gate region and the diffusion region. The silicide layer extends beyond a depletion region of the transistor edge, forming a Schottky diode junction. If necessary, the position of the diffusion region relative to the silicide is reinforced through thermal activation. This can be accomplished by laser or a flash anneal process.
[0010] According to another embodiment of the present invention, a method for forming a silicon-on-insulator transistor device includes the steps or acts of: exposing the sidewalls of a diffusion region of the transistor using an intentional pull-down of its shall trench isolation dielectric; depositing metal on the device such that the sidewalls and top of the diffusion region are covered in metal; and performing silicidation on the diffusion region to form a metal-silicon alloy to act as a contact, such that the silicide layer extends into and directly touches the transistor channel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] To describe the foregoing and other exemplary purposes, aspects, and advantages, we use the following detailed description of an exemplary embodiment of the invention with reference to the drawings, in which:
[0012] FIG. 1 shows a schematic diagram of a dual-sided Schottky device, according to an embodiment of the present invention;
[0013] FIG. 2 shows a top view of the physical structure of a structure, according to an embodiment of the present invention;
[0014] FIG. 3 a is a front view of the structure of the embodiment of FIG. 2 , according to the known art;
[0015] FIG. 3 b is a front view of a dual-sided Schottky body tied SOI device, according to an embodiment of the present invention;
[0016] FIG. 4 is a flow chart of a method of producing the structure of the above embodiment.
[0017] While the invention as claimed can be modified into alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the scope of the present invention.
DETAILED DESCRIPTION
[0018] We discuss a new structure used to form a dual-sided Schottky body tied SOI device. The structure is self-aligned, has no detrimental parasitics, does not consume any of the device's electrical width, and does not require masking or special implants. The key aspect of the new Schottky device is an intentional recess formed in the shallow trench isolation (STI) oxide portion of the device that extends past the silicide layer.
[0019] During the source/drain silicidation step, the silicide on the edge of the device will extend further, since there is a metal source both from the top and side. The diffusion junction is then placed so that it is extends past the silicide in the center of the device (normal diffusion to body junction), whereas the silicide extends past the junction of the device edges (Schottky junction). The required STI recess in unmasked (blanket wafer) and no transistor electrical width is consumed as there is no alteration of the gate or deep diffusion implant.
[0020] Referring now in specific detail to the drawings, and particularly FIG. 1 , there is illustrated a schematic diagram of the dual-sided Schottky device 100 , according to an embodiment of the present invention. The device comprises first 102 and second 104 Schottky devices coupled at their anodes 106 and having their respective cathodes coupled to the source 112 and drain 114 of a field effect transistor (FET) 108 . A FET 110 has a drain coupled to Vdd (Voltage drain drain—positive operating voltage of a field effect semiconductor device) and a gate coupled to the drain 114 of FET transistor 108 . In this embodiment the gate of FET transistor 108 represents the word line and its source 112 represents the bit line.
[0021] Referring to FIG. 2 there is shown a top view of the physical structure of device 200 . The central region 206 operates as a poly Silicon gate 206 . The drain 202 is shown on the left and the source 204 on the right. The arrows indicate the flow of current. The center arrow depicts the current flow from drain 202 to source 204 in an Nfet (negative channel field effect transistor), assuming positive voltage drops (Vds). Active region 208 is shown to the right. Since there is no doping alteration, there is no current loss.
[0022] FIG. 3 a shows a front view of the structure of the embodiment of FIG. 2 . The structure comprises the drain 202 , the source 204 and a gate 206 . In addition, a first layer 209 of silicide is deposited over the drain 202 and a second layer 211 of silicide is deposited over the source 204 . A layer 207 of gate oxide is located between the gate 206 and the drain to source channel. FIG. 3 a shows a standard FET region in the middle of the FET. FIG. 3 b shows the same structure, but with the silicide layers 209 211 encroaching past the diffusion junction 250 , directly touching the SOI body 201 . The Silicide 209 211 at the transistor edge extends beyond the depletion region, creating a Schottky diode junction.
[0023] Referring to FIG. 4 there is shown a flow chart 400 of a method of producing the structure of the above embodiment. In particular, FIG. 4 is a flow chart illustrating a method for producing a Self-aligned SOI Schottky Body Tie Employing Sidewall Silicidation according to an embodiment of the invention. The input to the method is an SOI device such as the one shown in FIG. 1 .
[0024] Receiving the device of FIG. 1 as input, the method proceeds at step 402 by exposing the sidewalls 285 in the trench of the SOI device using an intentional pull-down of the shallow trench isolation (STI) dielectric 280 . The sidewalls 285 are exposed to a free surface (such as air) until there is no material, such as oxide, in contact with the sidewalls 285 .
[0025] Following this, in step 404 a metal is deposited such that both the sidewalls 255 and top 258 of the device diffusion region 250 is covered in metal. The metal can be, but is not limited to, any one of the following: Nickel, Cobalt, Nickel and Platinum, and Erbium, Ytterbium. Next in step 406 the silicidation step is performed. Silicidation is an annealing process that results in the formation of a metal-Si alloy (silicide) to act as a contact. A silicide is an alloy of silicon and metals. During the silicidation step, the device diffusion region encroaches closer to the channel (depletion region).
[0026] Lastly, in step 408 thermal activation techniques (such as laser and flash anneal) may be performed if necessary to reinforce the position of the diffusion region relative to the silicide so that at the end of the process, the silicide layer extends past the junction of the device edges.
[0027] Therefore, while there has been described what is presently considered to be the preferred embodiment, it will understood by those skilled in the art that other modifications can be made within the spirit of the invention. The above description of an embodiment is not intended to be exhaustive or limiting in scope. The embodiment, as described, was chosen in order to explain the principles of the invention, show its practical application, and enable those with ordinary skill in the art to understand how to make and use the invention. It should be understood that the invention is not limited to the embodiment described above, but rather should be interpreted within the full meaning and scope of the appended claims. | A self-aligned transistor device includes: a source region and drain regions disposed on an oxide layer; a channel with a diffusion region formed between the drain and source regions; a silicide layer over a top surface of the source and drain regions, extending into the diffusion region; and a recess formed on each end of the device to expose sidewalls of the device to a free surface by performing shallow trench isolation on the oxide layer of the device that extends past the silicide layer. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to the field of small watercraft and, more particularly, to an improved air-intake system for use on a small watercraft.
[0003] 2. Description of Related Art
[0004] Personal watercraft have become increasingly popular in recent years. This type of watercraft is sporting in nature; it turns swiftly, is easily maneuverable, and accelerates quickly. A personal watercraft today commonly carries one rider and possibly one or two passengers.
[0005] A relatively small hull of the personal watercraft, comprising an upper deck and a lower hull, commonly defines a riders' area above an engine compartment. An internal combustion engine frequently powers a jet propulsion unit which is positioned in a tunnel formed on the underside of the watercraft hull. The propulsion unit propels the watercraft. The engine lies within the engine compartment, below the riders' area. An exhaust system extends between the engine and a discharge opening to expel exhaust gases either to the atmosphere or to the water. The exhaust system usually includes a water trap device that inhibits a reverse flow of water through the exhaust system from the discharge opening toward the engine.
[0006] It has become commonplace for small watercraft, such as for example, personal watercraft, to be operated in virtually any water condition, including ocean surf. Due to the design of the engine-air path, it is often possible for such small watercraft to operate for short periods of time submerged or in a substantially non-vertically oriented position. By drawing its air supply from the internal engine compartment of the small watercraft, these small watercraft engines are generally able to avoid periodic interruptions in the engine-air supply occasioned by waves or other rough weather conditions submerging the external air intakes.
SUMMARY OF THE INVENTION
[0007] The present invention includes the recognition that prior layout of the engine and exhaust components in the watercraft's engine compartment can lead to reduced engine performance under some operating conditions. One such instance is when a significant amount of water fills the engine compartment. Where the small watercraft experiences extremely rough water conditions such as ocean surf, or is being maneuvered sharply at high speeds, a significant amount of water can quickly flow through the air ducts into the engine compartment of the watercraft. This influx of water, combined with the water already present inside the engine compartment of the watercraft, can possibly submerge or splash into the air-intake(s) of the watercraft engine. Furthermore, this trapped water will often contact various moving parts of the engine, such as a coupling between the engine's crankshaft and the impeller shaft, which will cause further splashing of water in the engine compartment. Where water enters the air-intake(s), this water will become entrained in the fuel/air change delivered to the engine's cylinders, which can cause the engine to lose power, sputter, stall, or, in extreme conditions, possibly damage the engine components.
[0008] While it is possible to reduce the amount of water present in the engine compartment through the use of additional bilge pumps or special hull designs, such solutions increase the number and weight of components in the small watercraft and/or may minimize the cooling-air flow through the engine compartment. In addition, it is extremely difficult to remove all water from the engine compartment. A need therefor exists for a device that reduces the possibility of a small watercraft engine intaking water in the engine compartment during rough water conditions and/or high speed maneuvers.
[0009] In addition, the exhaust system of the engine can become quite hot after extended periods of watercraft operation. The heat from the exhaust system, and in particular, from the water trap, which usually functions also as an expansion chamber or muffler, heats the surrounding air in the engine compartment. When the engine intakes the heated air, a fuel/air ratio of the produced fuel/air charge does not correspond to a desired fuel/air ratio because the heated intake air has less oxygen per given volume than normal. Engine performance consequently suffers. Accordingly, a need exists for inhibiting a flow of air within the engine compartment from the space surrounding the water trap to the engine's induction system.
[0010] In accordance with one aspect of the present invention there is provided an improved intake system for use with a small watercraft engine located within the engine compartment of a small watercraft. The intake system comprises an air-intake box connected to the air-intake pipes of an engine located within the engine compartment of a small watercraft. The air intake box incorporates valves which serve to isolate the air intake box from splashing water in the engine compartment, thereby preventing the small watercraft from intaking a substantial amount of water. This air-intake box also permits the engine to briefly operate while the entire air-intake box is submerged.
[0011] Another aspect of the present invention involves extending a portion of the flywheel case over the flywheel and crankshaft coupling. This extension will redirect any water spray caused by the moving crankshaft coupling, thereby preventing such spray from entering the air-intake and being ingested by the engine. The extension also acts as a heat insulator, reducing the ambient heat level in the engine compartment near the air-intake system and inhibiting air flow from about this heated exhaust system with trap to the air-intake system.
[0012] Another aspect of the present invention involves the positioning of the engine in the engine compartment of the small watercraft. In one embodiment, the engine is tilted approximately 10 degrees towards the engine exhaust side of the engine, thereby raising the air-intakes of the engine above the air-exhausts. This orientation allows an air-intake box of the present invention to be attached to a standard small watercraft engine without substantially changing the air-intake/exhaust components and/or hull design.
[0013] In another aspect of the present invention is provided an improved valve design for use on the external hull of the watercraft, which prevents water from entering the engine and/or propulsion chamber through the intake-air ducts when the watercraft is inverted or in a substantially non-vertical orientation. This is accomplished by providing buoyant closures in air duct valves which are normally open but, when submerged, operate to close the air ducts and prevent water from traveling through the duct. Once the watercraft is returned to its substantially upright position, the buoyant closures reopen the air duct, returning air flow to the engine.
[0014] Further aspects, features and advantages of the present invention will become apparent from the detailed description of the preferred embodiment which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The above-mentioned and other features of the invention will now be described with reference to the drawings of a preferred embodiment of the present watercraft. The illustrated embodiments are intended to illustrate, but not to limit the invention. The drawings contain the following figures:
[0016] [0016]FIG. 1 is a longitudinal cross-sectional side view of a small watercraft in accordance with preferred embodiment of the present invention;
[0017] [0017]FIG. 2 is a sectional, top plan view of the small watercraft of FIG. 1 with portions of the components as an upper deck shown in phantom;
[0018] [0018]FIG. 3 is a lateral cross-sectional view of the small watercraft of FIG. 1;
[0019] [0019]FIG. 4 is a side view of a rubber valve member construed in accordance with a preferred embodiment of the present invention;
[0020] [0020]FIG. 5 is a cross-sectional side view of the rubber valve member of FIG. 3 with the valve illustrated in an open position and phantom lines illustrating a closed position;
[0021] [0021]FIG. 6 is a cross-sectional side view of another embodiment of a rubber valve member constructed in accordance with the present invention;
[0022] [0022]FIG. 7 is a cross-sectional rear view of a small watercraft incorporating another embodiment of the present invention;
[0023] [0023]FIG. 8 is a side, perspective view of an intake merging box constructed in accordance with the present invention;
[0024] [0024]FIG. 9 is a sectional side elevational view of a small watercraft incorporating an additional embodiment of the present invention;
[0025] [0025]FIG. 10 is a sectional top plan view of the small watercraft of FIG. 8 and illustrates several components on the upper deck in phantom;
[0026] [0026]FIG. 11 is a cross-sectional rear view of the small watercraft of FIG. 8;
[0027] [0027]FIG. 12 is a partial sectional side view of a small watercraft incorporating another embodiment of the present invention;
[0028] [0028]FIG. 13 is a partial sectional top plan view of the small watercraft of FIG. 11;
[0029] [0029]FIG. 14 is a cross-sectional rear view of the small watercraft of FIG. 11;
[0030] [0030]FIG. 15 is a cross-sectional rear view of a small watercraft incorporating an additional embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0031] [0031]FIGS. 1 through 3 illustrate different views of a small watercraft incorporating an air intake box and engine arrangement configured in accordance with a preferred embodiment of the present invention. While the present invention has particular utility with a small watercraft having an engine located within the engine compartment of the small watercraft, some aspects of the present equal utility with watercraft utilizing external-hull air intakes or externally mounted engines. As such, the invention will be described with the small watercraft design in this context; however, it is understood that the present invention may also be employed on other types of watercraft.
[0032] The following description describes several embodiments of the present invention which include unique induction system construction and orientation within the engine compartment. Where appropriate, the same reference numerals have been used between the various embodiments to indicate like components. In addition, various aspects of the different embodiments can be incorporated into the other embodiments, as will be readily apparent to those skilled in the art.
[0033] With initial reference to FIGS. 1 through 3, a small watercraft, indicated generally by reference numeral 1 , includes a hull 3 formed by a lower hull section 2 a and upper deck section 4 . These hull sections 2 a , 4 are formed from a suitable material such as, for example, a molded fiberglass reinforced resin. For instance, the deck 4 and the hull 2 a can be formed using a sheet molding compound (SMC), i.e. a mixed mass of reinforced fiber and thermal setting resin, that is processed in a pressurized, closed mold. The molding process desirably is temperature controlled such that the mold is heated and cooled during the molding process. For this purpose, male and female portions of the mold can include fluid jackets through which steam and cooling water can be run to heat and cool the mold during the manufacturing process. The lower hull section 2 a and the upper deck section 4 are fixed to each other around the peripheral edges in any suitable manner commonly known to those skilled in the art.
[0034] As viewed in a direction from the bow to the stern of the watercraft, the upper deck section 4 includes a bow portion 2 , a control mast 7 , a front seat 5 and a rear seat 6 . The bow portion 2 slopes upwardly toward the control mast 7 and includes at least one air duct through which air can enter the hull 3 .
[0035] The control mast 7 extends upward from the bow portion 2 and supports a handlebar assembly 150 . The handlebar assembly 150 controls the steering of the watercraft in a conventional manner well known to those skilled in the art. The handlebar assembly also carries a variety of the controls of the watercraft such as, for example, a throttle control, a start switch and a lanyard switch. The handlebar assembly 150 is enclosed by a handle cover 155 and is pivotally provided in front of the front seat 5 .
[0036] A hatch cover 9 is provided in front of the steering handle 7 . The hatch cover 9 is secured to the upper deck 4 by a hinge 9 a , and is able to open and close freely, thereby exposing the forward section of the interior of the hull 3 . A latch (not shown) is provided to secure the hatch cover 9 in its closed position during operation of the watercraft 1 . A storage box 8 is removably provided in the deck below the hatch cover 85 . This storage box 8 is covered by the hatch cover in a water sealing manner.
[0037] A forward air opening 160 , located adjacent to the front seat 5 , desirably allows ambient air traveling over the upper deck 4 to travel below the front bottom plate 5 a of the front seat 5 . This airflow then travels into an air inlet port 25 a , located below the front seat 5 , and into the air duct 25 . A rearward air opening 175 , located behind the rear seat 6 , desirably allows ambient air to travel through cover 27 , through air inlet port 26 a , and into the rear-air duct 26 .
[0038] The front and rear seats 5 , 6 , are desirably straddle-type seats having an elongated shape that extends along the longitudinal axis of the watercraft. These seats are centrally located between the sides of the hull and are mounted on front bottom plate 5 a and rear bottom plate 6 a , respectively. In the illustrated embodiment, the rear seat 6 is positioned at an elevated level relative to the front seat 5 . This advantageously positions the riders at different levels.
[0039] A fuel tank 12 is located within the hull 1 . A fuel supply pipe 12 a extends from the surface of deck 4 to the fuel tank 12 . Conventional means such as straps (not shown) secure the fuel tank to the lower hull 2 a . In the illustrated embodiment, a filler cap assembly 165 is secured to the bow portion 2 of the hull upper deck 4 . In this manner, the fuel tank 12 may be filled from outside the hull 1 with the fuel passing through the fuel supply pipe 12 a into the tank 12 .
[0040] A bulkhead 15 desirably is vertically provided behind the engine 10 and divides the hull 3 into an engine chamber or compartment 13 and a propulsion chamber 14 . Air ducts 25 , 26 , for guiding air into the engine chamber 13 , are provided in the forward/rear parts of the engine chamber. Air inlet ports 25 a , 26 a of each air duct 25 , 26 are located in openings formed in the upper deck 4 . Air-outlet ports 25 b , 26 b of each air duct are respectively opened to the forward and rear sides of the engine 10 . These air outlet ports 25 b , 26 b are positioned lower than the engine intake-air system (to be described later) so as to prevent water flowing through the air ducts 25 , 26 from traveling directly into the engine intake-air system. Although air is supplied to the engine compartment 13 though both ducts, a flow of air from the front duct to the rear duct also occurs to air cool the engine and the other components of the watercraft located in the engine compartment 13 .
[0041] A jet propulsion unit, indicated generally by reference numeral 16 , is provided in the pump chamber 21 . This jet propulsion unit 16 includes an impeller shaft 19 to which an impeller 18 is fixed. The impeller shaft 19 is positioned in the longitudinal directions and extends through a propulsion duct 17 that has a water inlet port 17 a positioned on the keel of the lower hull section 2 a . The lower hull section 2 a includes an opening at the stem 2 b of the watercraft 1 in which a jet outlet port 17 b of the propulsion unit 16 is positioned. A front end of the impeller shaft 18 and an output shaft 40 (e.g.-a crankshaft) of the engine are coupled through a conventional shock-absorbing coupling 41 to transfer power from the crankshaft to the impeller shaft. The propulsion unit 16 generates the propulsive force by applying pressure to water drawn up from the water inlet port 17 a by means of the rotation of the impeller shaft 18 , and forcing the pressurized water through the jet outlet port 17 b in a manner well known to those skilled in the art.
[0042] A nozzle deflector or steering nozzle 20 is connected to the jet outlet port 17 b of the propulsion unit 16 . The nozzle deflector 20 desirably moves in the left/right and vertical directions via a known gimbal mechanism. The nozzle deflector 20 is connected to the handlebar assembly 150 through a steering mechanism and trim mechanism (not shown), whereby the steering and trim angles may be changed by the operation of the handlebar assembly 150 and associated trim controls.
[0043] The upper deck 4 of the watercraft includes a longitudinally extending pedestal 170 , preferably formed as part of the upper deck. The pedestal 170 supports the front and rear seats 5 , 6 . Foot areas 4 b are formed along side this pedestal 170 , between the pedestal 170 and a pair of raised side gunnels or bulwarks 4 a that extend along the outer sides of the watercraft. These foot areas 4 b are sized to accommodate the lower legs and feet of the riders who straddle the front and rear seats 5 , 6 when seated. In the illustrated embodiment, a deck 4 b ′, formed at the rear of the watercraft behind the pedestal, extend above the propulsion unit 16 and allow eased entry into the watercraft 1 , as is well known in the art.
[0044] A maintenance opening 4 c is formed on the top surface of the seat pedestal 170 and is desirably positioned below the rear seat 6 . This maintenance opening 4 c is covered by the rear bottom plate 6 a in a water-sealing manner. The engine chamber 13 can be accessed through this maintenance opening 4 c by removing the rear seat 6 .
[0045] An in-line, three-cylinder, four-cycle engine 10 is mounted in the center of the main body of the watercraft; however, other types of engines also can be used to power the watercraft. For instance, engines with other numbers of cylinders, with other cylinder arrangements and which operate on other operating principles (e.g., two-stroke) can be used for this purpose.
[0046] The general construction of the four-stroke 10 is well known to those of ordinary skill in the art. As depicted in FIGS. 1 and 2, the engine 10 comprises cylinder block 10 b , a cylinder head 10 c , head covers 10 d , and a crank case 10 a . Intake valves 43 are disposed in the cylinder head 10 c for controlling the delivery of a fuel/air mixture to the cylinders of the engine 10 . Exhaust valves 44 are similarly disposed in the cylinder head 10 c for controlling the expulsion of exhaust gases. Opening and closing of the intake and exhaust valves is regulated by the operation of the camshafts 45 , the sprockets 46 , 47 , and the timing chain 48 . The timing chain 48 is connected to the drive sprocket 47 , and is enclosed by a cover 49 which protects the timing chain 48 and prevents accidental contact between a rider and the chain during maintenance of the engine 10 .
[0047] Power from the crankshaft 40 is transferred to the impeller shaft 19 through the coupling 41 . The crankshaft 40 also carries a flywheel 77 on the rear side of the engine 10 . A starter motor 78 rotates the crankshaft 40 through a ring gear 77 a formed on the periphery of the flywheel 77 , and operates to start the engine in a manner well known to those of ordinary skill in the art. An alternator 50 is connected to the crankshaft 40 , and coverts rotation of the crankshaft 40 into electrical power for the engine 10 and associated systems in a manner well known to those of ordinary skill in the art. For this purpose a drive pulley 51 located on the front side of the engine 10 is attached to the crankshaft 40 . A belt interconnects the drive pulley 51 to a pulley on the alternator 50 to drive the alternator in a known manner.
[0048] The flywheel 77 , located within the flywheel case 79 , is coupled to the crankshaft 40 to ensure smooth and even rotation of the crankshaft during operation of the engine 10 . The flywheel case 79 extends rearwardly, substantially surrounding the flywheel. In addition, this extension of the flywheel case will prevent water in contact with rotating coupling 41 from spraying into the engine intake-air system (to be described later). Furthermore, the flywheel case 79 acts as an insulator between the air in the engine compartment forward of the flywheel case 79 and the air in the engine compartment behind the flywheel case 79 . The case 78 also inhibits the airflow in the engine compartment in the forward direction, thereby limiting heating of the engine intake-air system and the intake air.
[0049] On top of the engine 10 is a lubricating oil supply port 56 , through which oil may be added to the engine 10 . An oil cap 57 closes and seals this supply port 56 , thereby preventing a loss of oil from the engine and ensuring that water does not contaminate the oil supply. An oil pan 10 e is provided in the bottom of the engine 10 . An oil filter 55 , located adjacent to the oil pan 10 e , is provided to continuously clean the engine oil. A drain plug 42 is provided in the oil pan 10 e to facilitate removal of engine oil for maintenance.
[0050] On one side of the engine 10 an exhaust system is provided. In this exhaust system, exhaust runners 60 extend from the side of the engine and downward into an exhaust-air merging box 61 . An exhaust-air merge pipe 61 a , extending rearwardly from the exhaust-air merging box 61 , connects to a front end of a water lock or trap 63 . The water lock 63 inhibits a reverse flow of water toward the engine. In the rear end of the water lock 63 , a through-hull exhaust pipe 64 is connected. This exhaust pipe 64 extends upwardly and across the hull and over the pump chamber, and is connected to a pump chamber of the watercraft to exhaust at this location. The outlet of the exhaust pipe 64 can also be located on the lower surface of the hull, on the transom of the hull or on the side of the hull.
[0051] The engine 10 desirably is oriented within the hull 3 to locate a crankshaft 40 of the engine 10 along a longitudinal axis of the main body. The engine 10 is mounted above the lower hull section 2 a of the watercraft through a damper member or mount 11 . As best depicted in FIG. 3, in one embodiment of the present invention the engine 10 is mounted such that the cylinder block 10 b is skewed from vertical such that the axes of its cylinders are about by approximately 10 degrees off vertical. This engine orientation places the engine-air intake approximately 2 to 3 inches above the engine-air exhaust. This rotation permits an intake-air merging box 73 (to be described later) to be positioned in the intake air system without requiring substantial redesign of the intake system components, engine design and/or an increase in the cross-sectional width of the seat pedestal. Furthermore, the increased height of the engine-air intake allows the intake-air merging box to be generally equally distanced from the upper deck and the lower deck of the small watercraft, a location that is least subject to water invasion during operation of the small watercraft.
[0052] The intake air system comprises fuel/air-intake pipes 70 connected to intake passage of the engine 10 which communicate with the engine's cylinders through the valve 43 . The fuel/air intake pipes 70 also communicate with at least one charge former. In the illustrated embodiment, the opposite end of each intake pipe 70 is connected to carburetors 71 . The carburetors 71 vaporize and mix fuel with the intake-air, and regulate this fuel/air mixture using butterfly-type throttle valves 72 , in a manner well known to those skilled in the art.
[0053] As can best be seen in FIGS. 1 and 3, the carburetors 71 are also connected to air intake pipes 175 , which are in turn connected to an intake-air silencer 73 . The intake-air silencer is connected to an air filter 74 , which is in turn connected to the intake box 75 . A trumpet-shaped air-inlet port 75 a is disposed on the bottom surface of the intake box 75 , which allows air to be drawn into the intake box 75 at a low velocity while inhibiting entrance of water. The intake box 75 is located on the front side of the engine with its opening facing down. Water entrained in the air flow desirably is separated in the intake box 75 and is drained through the downward opening 75 a.
[0054] As best seen in FIG. 2, the case 79 of the flywheel 77 lies between the intake silencer 73 , as well as the balance of the components of the induction system, and the watertrap 63 and the exhaust pipe 64 . At this location, the casing 79 generally insulates, at least to some degree, the induction system from the heat radiated by the exhaust system, principally by the water trap 63 and the exhaust pipe 64 . The casing also inhibits air from the rear of the engine compartment toward the intake opening 75 a . The casing 79 , as mentioned above, also generally shields the intake port 75 a from water which may be splattered by the rotating coupling 41 and the associated shafts. As a result, the air entering into the intake box 75 generally contains less water vapor and is cooler than the air circulating about the rear end of the engine compartment.
[0055] [0055]FIG. 4 shows a rubber valve member 30 constructed in accordance with one embodiment of the present invention. This type of valve 30 is desirably disposed at the upper end of each axis inlet port 25 a , 26 a of the front and rear air ducts 25 , 26 .
[0056] Rubber valve member 30 is comprised of peripheral walls 30 a and disc 30 c . Air windows 30 b are formed in the walls 30 a . The lower section of the peripheral walls 30 a encircles and is secured to an external projection of each air inlet port 25 a , 26 a . A flange 180 , formed integral with and perpendicular to the air inlet port 25 a , 26 a , secures the air inlet port to the upper deck 4 of the watercraft 1 . In the preferred embodiment, the peripheral walls 30 a and disc 30 c are formed of a buoyant, flexible material such as a low density foam rubber.
[0057] As shown in FIG. 5, during normal operation, the disc 30 c of the rubber valve member 30 is supported by the peripheral walls 30 a , thereby allowing air to travel through the air windows and into the air ducts 25 , 26 . However, when the watercraft is inverted and the rubber valve member is submerged, the natural buoyant forces acting on the disc overcome the strength of the column-like wall 70 a exerted by the peripheral walls 30 a , thereby buckling the peripheral walls 30 a and allowing the disc 30 c to assume new position 30 c ′, effectively sealing the air ducts 25 , 26 and preventing further water from entering the watercraft. When the watercraft resumes its normal orientation, this buoyant force on the disc is removed, thereby allowing the spring force exerted by the peripheral walls 30 a to lift the disc 30 c into its normal operating position and resuming the flow of air into the air ducts 25 , 26 .
[0058] [0058]FIG. 6 shows an alternate embodiment of a valve member constructed in accordance with the present invention. Spring valve 185 is comprised of buoyant block 31 , spring valve shaft 190 , spring 32 , shaft support 33 , and stopper pin 34 . A flange 180 , formed integral with and perpendicular to the air inlet port 25 a , 26 a , secures the air inlet port to the upper deck 4 of the watercraft 1 . The shaft support is disposed within the respective air inlet port 25 a , 26 a.
[0059] During normal operation of the spring valve 185 , the lower surface of the buoyant block 31 is held above the upper surface of the air inlet ports 25 a , 26 a by a force exerted by the spring 32 , thus allowing air to travel into the corresponding air duct 25 , 26 . Vertical motion of the buoyant block is limited by the interaction of stopper pin 34 with the lower surface of the shaft support 33 . When the watercraft is inverted and the spring valve 185 is submerged, however, buoyant forces acting on the buoyant block are greater than the force exerted by the spring, thereby allowing the buoyant block to travel towards and abut the air inlet ports 25 a , 26 a . This substantially seals the air inlet ports and prevents water from entering the engine compartment of the watercraft. When the watercraft resumes its normal orientation, the buoyant force on the buoyant block is removed, thereby allowing the force exerted by the spring to lift the buoyant block off of the air inlet port 25 a , 26 a , and resuming the flow of air into the corresponding air duct 25 , 26 .
[0060] With reference now to FIGS. 7 and 8, depicted is a small watercraft incorporating another embodiment of an intake-air merging box constructed in accordance with the present invention. The intake-air merging box 73 is comprised of a ceiling wall 73 b , an inner wall 73 c , a bottom wall 73 d , an outer wall 73 e and two cap walls 73 f and 73 g , bonded together to form a watertight box. Disposed in the inner wall are trumpet-shaped intake ports 80 , which allow air to be drawn into the merging box 73 at a low velocity while inhibiting entrance of water. Disposed in the ceiling and bottom walls 73 b , 73 d are drain holes 81 a , 81 b , which permit water trapped within the merging box 73 to drain into the engine compartment 13 . While this embodiment of an intake-air merging box 73 is a square or rectangular box, it should be noted that various other shaped boxes may be used with equally utility.
[0061] As can best be seen from FIG. 7, air-intake pipes 175 connect the carburetors to the intake-air merging box 73 . These air-intake pipes are comprised of upstream parts 70 a , located adjacent to the carburetors, and expanding parts 70 b , located within the intake air merging box 73 . The trumpet-shaped design of the expanding parts 70 b allows air to be drawn into the air-intake pipes at low velocity while inhibiting water from being drawn into the air-intake pipes.
[0062] [0062]FIGS. 9 through 11 depict a small watercraft 100 incorporating an additional embodiment of an air intake system constructed in accordance with the present invention. In this embodiment, the engine 10 utilizes a charge forming device such as a fuel injector 101 (see FIG. 11) for forming the fuel/air mixture utilized in the engine 10 . Air is supplied to the engine through a number of intake pipes 102 connected to the engine 10 . The opposite ends of the intake pipes 102 are connected to an intake-air merging pipe 103 , which is in turn connected to a throttle body 104 . The throttle body is connected to the intake box 106 , and an air filter 105 is disposed within the intake box 106 to clean and filter air passing into the engine 10 . An intake opening 106 a is located on the bottom surface of the intake box 106 .
[0063] In operation, the air intake system of the small watercraft of FIGS. 9 through 11 will draw air into the intake opening 106 a , through the filter 105 , through the throttle body 104 , and into the air merging pipe 103 . Air in the air merging pipe will subsequently be drawn into and through the intake pipes 102 and into the engine 10 where it will be mixed with fuel sprayed from one or more fuel injectors 101 .
[0064] As seen from FIGS. 9 and 10, the intake box 105 is positioned behind the flywheel casing 79 and to one side of the longitudinal axis opposite the side on which the water trap 63 is located. At this location, the inlet 106 a of the intake box 106 is located next to the lower end of the rear intake duct 26 . At this location, fresh air can enter the intake box while experiencing minimal heating. In addition, the flywheel casing 79 generally insulates the intake box from the engine so as to reduce the heating effect of the intake air from the intake duct 26 into the intake box 106 , as well as to inhibit air flow from the front intake duct 25 across the engine 10 to the intake duct 106 . Consequently, the induction system intakes less air heated by the engine and more fresh air flowing through the rear intake duct 26 .
[0065] In addition, the coupling between the impeller shaft 19 and the output shaft of the engine 10 is enclosed within the casing 79 . As a result, the rotating components within the engine compartment tend to splatter less water about the engine compartment.
[0066] Turning now to FIGS. 12 through 14, there is depicted a small watercraft or jet boat 110 , incorporating another embodiment of an air intake system constructed in accordance with the present invention. As viewed from the bow to the stern, the hull 112 of the jet boat 110 includes floor 113 a and a bench-type seat 114 located forward of an aft end 111 of the watercraft. A steering handle is positioned forward of the bench-type seat, and controls the steering of the watercraft in a conventional manner well known to those skilled in the art. A deck section 113 is fixed to the hull 112 around the peripheral edges in a manner well known to those skilled in the art. As can best be seen from FIG. 14, the engines 10 are skewed by approximately 10 degrees from vertical.
[0067] A maintenance opening 113 b is provided in the deck section 113 to provide access to the engine chamber 13 . An engine hatch 120 , attached to the deck by a rear hinge 120 a , closes the maintenance opening 113 b in a watertight manner. Two storage boxes 121 , 122 are positioned in the engine chamber.
[0068] A storage chamber 119 , located underneath the bench-type seat 114 , is formed between front dividing wall 117 and rear dividing wall 118 , and contains a fuel tank 116 . Two storage boxes 121 , 122 , are located within the engine chamber 13 and are disposed alongside the outer side of each engine 10 . A battery 123 is positioned within one of the storage boxes 121 . Electrical engine control components 124 well known to those skilled in the art, such as computer control circuits, are located in the opposite storage box 122 .
[0069] On one side of each engine 10 an exhaust system is provided. In this exhaust system, exhaust pipes 130 extend from the side of the engines and downward into an exhaust-air merging pipe 131 . The exhaust-air merging pipe extends rearwardly and connects to a front end of a water lock or trap 63 . The water lock 63 inhibits a reverse flow of water toward the engine. In the rear end of the water lock 63 , a through-hull exhaust pipe 64 is connected. This exhaust pipe 64 extends upwardly and across the hull and over the pump chamber, and is connected to a pump chamber of the watercraft to exhaust at this location.
[0070] In the embodiment depicted in FIGS. 12 through 14, the engines 10 are cooled by a liquid cooling system comprising water jackets 133 , coolant inlet ports 134 , water ports 135 , coolant hoses 136 , and coolant drain ports 137 . In operation, cooling water is pumped into the water ports 135 and travels through the cooling hoses into coolant inlet ports 134 . This flow of cooling water travels into the water jackets 133 , and comes in contact with the cylinder block 10 b , the cylinder heads 10 c , and the engine exhaust pipe 130 . The cooling water than travels into the exhaust pipe, travels through the water lock 63 , and is discharged out of the jet boat through the through-hull exhaust pipe 64 .
[0071] The intake air system comprises intake pipes 140 connected to air inlets of the engines 10 . The opposite ends of these intake pipes 140 are connected to an intake air merging pipe 141 . The intake air merging pipe extends rearwardly and through the bulkhead 15 , and connects to an intake air port 141 a which is open to the propulsion chamber 14 . An air inlet port 142 is provided in the upper deck 113 which allows outside air to travel into the propulsion chamber 14 . A cover 143 , located over the air inlet port 142 , prevents water from entering the propulsion chamber.
[0072] [0072]FIG. 15 depicts the jet boat of FIG. 12 through 14 , incorporating an additional embodiment of the present invention. In this embodiment, the engines 10 are positioned such that the cylinders of the engines 10 are skewed by approximately 10 degrees left and right, respectively, from vertical, thus forming a V-shape. This embodiment provides for increased separation between the engines, facilitating maintenance and removal of the engines, if required. The increased spacing between the exhaust system of one engine and the induction system of the other engine will further reduce the temperature of the air used to form the fuel/air charge.
[0073] Accordingly, although this invention has been described in terms of certain preferred embodiments, other embodiments apparent to those of ordinary skill in the art are also within the scope of this invention. Of course, a watercraft need not include all of these features to appreciate some of the aforementioned advantages associated with the present watercraft. Accordingly, the scope of the invention is intended to be defined only by the claims that follow. | An improved air-intake system and engine layout for use on a small watercraft provides for a lower temperature, vapor fuel/air charge with less water vapor content. The watercraft includes an engine-air intake system incorporating an air-intake box which inhibits the engine from intaking water present in the engine compartment, especially during high speed maneuvering. An extended flywheel case is also provided that prevents water located in the engine compartment from being sprayed by moving parts directly into the air-intake box. Furthermore, the improved air-intake system of the present invention incorporates external air-intake valves that prevent water from entering the engine and propulsion compartments through the air intakes while the watercraft is in an inverted. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to locks and, more particularly, to an improved lock for bicycles, motorcycles, scooters, mopeds and the like.
2. The Prior Art
The numbers of bicycles, motorcycles scooters, mopeds and the like in daily use have increased dramatically lately. Some of these items are now quite expensive. Thefts of these items also have increased dramatically. These items, once stolen, represent not only considerable loss to their owners, but also are difficult to trace and to recover. Professional and some not so professional thieves nowadays frequently employ a bolt cutter, a long lever or the like to sever or break quickly and quietly cables, chains or other devices used to secure bicycles and the like to posts or other fixed objects. To guard thereagainst, large heavy locks have been developed comprising rigid U-shaped shackles and cross bars designed to attach to the ends of the shackles. See U.S. Pat. Nos. 3,924,426; 3,967,475 and 4,155,231. These devices offer good resistance to bolt cutters, hack saws and the like.
More recently, a bicycle lock featuring a replaceable lock cylinder which may be identical to one used in the home or office and operable by the same key, has been developed. See the U.S. Pat. No. 4,545,224.
The present invention is an improvement over the Bicycle Lock and Bracket disclosed and claimed in U.S. Letters Pat. No. 4,155,231, granted May 22, 1979, and over the Bicycle Lock disclosed and claimed in U.S. Letters Pat. No. 4,545,224, granted Oct. 8, 1985, both assigned to a common assignee, KBL Corporation of Boston Massachusetts. See also U.S. Pat. No. 4,730,470, Zane et al, "Security Lock," granted Mar. 15, 1988.
The known art of locks in general goes back centuries. Locks specifically designed for bicycle security were introduced more recently. For various relevant locks, see the U.S. Pat. No. 187,362, entitled "Shackles," that was granted to H. W. Dilg on Feb. 13, 1877. It discloses a device whereby prisoner's ankles may be shackled. German Patent No. 105,187 issued in 1898 and discloses a bicycle lock in which the legs of a U-shaped shackle must be squeezed together before they are insertable into a cross piece. German Patent No. 111,976 is an addition thereto featuring an improvement in locking the same with the aid of a Chubb lock. U.S. Pat. No. 1,036,992, granted to G. S. Franki on Aug. 27, 1912, discloses a padlock featuring a cylindrical body with a cylindrical bore. A shackle extends through slots and into the base and is secured therein by a pin on the one hand and by another pin of a locking member. German Patent No. 824,896, issued in 1951, discloses a U-shaped bicycle lock in which a spring and tumbler device engages one leg of a shackle, securing thereby the shackle to a cross piece. And U.S. Pat. Des. Nos. 238,548 granted to R. N. Seaken on Jan. 27, 1976 and No. 4,085,600 granted to A. E. Bindari on Apr. 25, 1978 both disclose bicycle locks featuring a locking mechanism in the end of the cross piece.
A combined carrying and locking device for a cycle is disclosed in U.S. Pat. No. 4,256,322; while an antitheft device for a bicycle is shown in U.S. Pat. No. 4,271,690. U.S. Pat. No. 4,324,119 teaches a passive wheel lock for bicycles; U.S. Pat. No. 4,426,861 features a brake lock for motorcycles; and U.S. Pat. No. 4,524,591 shows a lock device for chain driven vehicles. A pick-proof locking system is shown in U.S. Pat. No. 4,584,855; while a combined vehicle and assembly locking and wrenching apparatus is disclosed in U.S. Pat. No. 4,674,306. U.S. Pat. Nos. 4,823,566 and 4,823,567 disclose padlock and locking mechanisms. A self-retracting security system for bicycles is illustrated in U.S. Pat. No. 4,870,843; while a shackle lock is disclosed in U.S. Pat. No. 4,881,387. The art is thus crowded yet remains open for improvements.
SUMMARY OF THE INVENTION
It is a principal object of the present invention to overcome some of the shortcomings of prior art devices by providing an improved bicycle lock which is both easier and more convenient to manipulate, as well as being of sturdier and of more compact construction.
More specifically, it is an object of the present invention to provide a locking device for bicycles and the like of the kind including a U-shaped shackle, formed with a pair of legs, a cooperating cross bar adapted to lock across the ends of the shackle, and means for securing the one to the other and featuring a lock mounted in the side of the cross bar and in between the legs of the shackle when the lock is assembled. The means for securing one leg of the shackle to the cross bar also functions as a fulcrum, permitting a tilting movement between the two parts, required in assembling and disassembling them. Preferably, the cross bar extends beyond the parallel outer profiles of the shackle's legs less than twice the diameter of one of those legs, resulting in a compact and sturdy design. Preferably, the means for securing one leg of the shackle to the cross bar comprises a bent foot sloping at an obtuse angle.
The lock preferably is removably mounted flush with and in the side of the cross bar and includes a member designed for limited axial displacement between a locking and a non-locking position relative to one end of the U-shaped shackle. The lock is securely held in place within the cross bar by either a ring or by a second member complementary to the first member, and encasing the lock. The lock preferably is a dead bolt lock. Preferably the cross bar and the first and second members define a cross section of one of a group comprising circular, rectangular, oval, pentagonal, hexagonal and octogonal.
A plastic cover preferably encloses at least the cross bar and is preferably formed of two parts slidably fitted over the cross bar over its respective ends. Centrally, the two parts can be secured to each other, inter alia, by welding or gluing the abutting or superimposed edges thereof. Preferably, means is provided on the lock to keep it free from dirt and dust, and the like.
Other objects of the present invention will in part be obvious and will in part appear hereinafter.
The invention accordingly comprises the locking device of the present disclosure, its components, parts and their interrelationships, the scope of which will be indicated in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the nature and objects of the present invention, reference is to be made to the following detailed description, which is to be taken in connection with the accompanying drawings, wherein:
FIG. 1 is a view in elevation and partly in section of a locking device for bicycles and the like constructed in accordance with the present invention;
FIG. 1A is a perspective view of the cover for one part of the locking device of FIG. 1;
FIG. 1B-1E are perspective views of various other covers for the one part of the locking device of FIG. 1;
FIG. 2 is a fragmentary view of a modification of the locking device shown in FIG. 1;
FIG. 3 is a section of the device of FIG. 1 along the lines 3--3 thereof;
FIG. 4 is an exploded perspective view of the locking mechanism of the device shown in FIG. 1 but on an enlarged scale;
FIG. 5 is an exploded perspective of parts of another embodiment of a locking mechanism according to the invention;
FIG. 6 is a perspective view of the parts shown in FIG. 5 but now in assembled condition;
FIG. 7 is a view similar to FIG. 5 but showing a further embodiment of a locking mechanism according to the invention;
FIG. 8 is sectional view illustrating the embodiment of the locking mechanism of FIG. 7 in a locked position;
FIGS. 9-11 are fragmentary perspective views of locking devices of different shapes according to the invention; and
FIGS. 12-13 are illustrative of further shapes, in cross section, of a part of locking devices according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Generally, the illustrated embodiment of an improved locking device 10 for securing bicycles and the like to a fixed object, such as a post, not shown, comprises a cross bar 12 shown in section in FIG. 1 and a U-shaped shackle 14 shown in fragmentary elevation, both in solid lines and in phantom.
Both the cross bar 12 and the shackle 14 preferably are made from a heat treated high grade hardened steel, and both are sufficiently sturdy and thick to present effective resistance to the action of a bolt cutter or a hack saw or a lever. The cross bar 12 preferably is of hollow tubular construction while the shackle 14 preferably is made from solid cylindrical rod stock. A covering skin 16 and 16a is shown provided on the outer surfaces of both the cross bar 12, and the shackle 14, respectively. Alternatively, the cross bar 12 also can be formed of hollow tubular internal construction but with different outer peripheries, such as rectangular, oval, pentagonal, hexagonal andoctogonal, as respectively illustrated in FIGS. 9-13. If desired, the shape of the internal construction of the cross bar 12 can follow its respective outer periphery.
The covering skin 16 and 16a preferably is provided to protect the finished surfaces of the bicycle against scratching when the locking device is applied. The covering skin 16 and 16a may be clear or colored and preferably is made of plastic or rubber, with the skin 16a being applied to the shackle 14 in any known manner as by dipping or by fitting a flexible sleeve over the shackle 14, as desired.
Applying the skin 16 to the cross bar 12 also can take several forms. As illustrated in FIGS. 1 and 1A, the skin 16 comprises two parts 116 and 118 which are slipped over the respective ends of the cross bar 12 and secured to one another by an interlocking hook 117 and eye 119 arrangement, respectively provided on the parts 116 and 118. A slidable lock cover 106 preferably is provided to cover the hole 34a that fits over the locking mechanism 34 and, when in place, provides dirt and dust protection therefor. Preferably, the lock cover 106 is formed with internal ribs 107 designed to project into and slide within cooperating tracks 109 provided on the part 118. The lock cover 106, being formed of a deformable plastic or rubber, is snapped in place, as shown in FIGS. 1 and 1B through 1E.
The two parts of the skin 16 covering the cross bar 12 also can take the shape and construction as illustrated in FIGS. 1B through 1D, as well as illustrated in FIG. 1E. The parts 116B and 118B illustrated in FIG. 1B differ from those described above in that their method of joining to one another is effected by the provision of a pair of projections 119B provided with hooked edges and fitting over appropriately shaped cooperative parts 117B, as by being snapped or twisted thereover. The parts 116C and 118C illustrated in FIG. 1C are similar to those shown in FIG. 1B and differ therefrom only in further providing an annular depression 111 in one part 118C and a thereinto projecting annular projection 113 provided in part 116C. The parts 116D and 118D illustrated in FIG. 1D are joined together as by being screwed to one another by the provision of a helical ridge 115 formed on part 116D being screwed into a corresponding helical groove 117 formed in the other part 118D. In either of the above embodiments, a suitable cement also can be employed, if desired.
In the embodiment illustrated in FIG. 1E, the two halves 101 and 103 are cut along their axial lengths and are provided with cooperating pairs of edges 91 and 93. With the application of either cement or sonic welding to these pairs of superimposed edges 91 and 93, the two halves 101 and 103 can be effectively joined to each other.
The shackle 14 is generally U-shaped and formed with a pair of legs 18 and 20 of substantially the same length. The legs 18 and 20 can be cylindrical or oval, depending on the end use. The leg 18 terminates in a bent end or foot 22. The foot 22 preferably is sloping outwardly at an obtuse angle from the longitudinal axis of the leg 18, substantially as shown. The leg 20, on the other hand, is straight and is provided with a transverse cut 24 facing toward the bent foot 22 of the leg 18.
The cross bar 12 is formed with a pair of aligned openings 26 and 28 in the upper side thereof. The openings 26 and 28 are spaced apart from one another by a distance corresponding to the distance between the legs 18 and 20 of the U-shaped shackle 14. The opening 26 is located near one end 30 of the tubular cross bar 12 and is somewhat oblong while the opening 28 is circular in cross section and located near the other end 32.
The Embodiment of FIGS. 1-4
A first preferred embodiment of an improved locking device according to the invention is illustrated in FIGS. 1-4. In this embodiment as well as in the other preferred embodiments hereinafter illustrated and described, a locking mechanism 34 is mounted in a side of the tubular cross bar 12 adjacent its end 32. It should be noted that the locking mechanism 34 is entirely disposed in the cross bar 12 in between the pair of legs 18 and 20, i.e., in between the pair of aligned openings 26 and 28. This mounting of the lock 34 in the side of the cross bar 10 is utterly unlike that taught by the prior art (note, inter alia, the U.S. Pat. No. 4,545,224), where the lock is mounted in the end of the cross bar. The locking mechanism 34 is mounted through a hole 36 formed in the side of the tubular cross bar 12 and diametrically but offsettingly opposed to the locations of the pair of openings 26 and 28, observe FIG. 1. As is evident from FIG. 1, the hole's 36 axis is parallel to, but is offset from, the axis of the opening 28. Consequently, a cylinder 38 of the locking mechanism 34 will enter into the interior of the tubular cross bar 12 in a space adjacent but not conflicting with that occupied by the leg 20 of the U-shaped shackle 14. The locking mechanism 34 preferably is so constructed that it does not protrude from the outer surface of the cross bar 12 so as to present a smooth outward appearance.
The locking mechanism 34, as best observed in FIG. 4, comprises the lock cylinder 38, a horseshoe-shaped yoke 40 designed to secure the lock cylinder 38 within the tubular cross bar 12, an elongated dead bolt, 42 that is cresent-shaped in cross section and is designed for limited positive axial displacement, as indicated by an arrow 44, and a cam 46 operatively coupling the lock cylinder 38 to a crescent-shaped seat 62 in dead bolt 42 so as to impart thereto the limited positive axial displacement between two operative positions: a first operative position, shown in solid lines in FIG. 1, in which the dead bolt 42 extends into the transverse cut 24 of the leg 20 of the U-shaped shackle 14, and a second position, shown in phantom in FIG. 1, in which the dead bolt 42 is withdrawn from the transverse cut 24, enabling thereby the removal of the leg 20 of the shackle 14 from within the opening 28 of the cross bar 12.
The lock cylinder 38 is formed with a pair of spaced parallel channels 48 and 50 about its periphery to accommodate the horseshoe-shaped yoke 40. The yoke 40, when in place about the lock cylinder 38, abuts on both sides against the inside surface of the tubular cross bar 12 as can be best observed in FIG. 3, and holds thereby the lock cylinder 38 securely within the cross bar 12. The lock cylinder 38 further is provided with a compression spring 52, the force of which needs to be overcome by a key 54 when the same is inserted into the cylinder 38 in order to operate the locking mechanism 34. Key 54 only can be inserted into and removed from the lock cylinder 34 when the locking mechanism 34 is in its locked position, illustrated in solid lines in FIG. 1. The key 54 remains firmly anchored in the lock cylinder 38 when the locking mechanism 34 is in its unlocked position. Lock cylinder 38 further is provided with a centrally located protruding shaped part 56 which rotates, together with a cylindrical member 57, when the key 54, properly inserted therein, is rotated about a ninety-degree arc, as illustrated by an arrow 58. Operative part 56 is contoured to fit within a cutout 60 formed in the cam 46. The cam 46 is, in turn, shaped to be accommodated within the cresent-shaped seat 62 formed in the underside flat surface 64 of the dead bolt 42. Due to the off-center location of the cutout 60 in the cam 46, the same imparts the limited positive axial displacement to the dead bolt 42 when the cam 46 is rotated within the seat 62.
With the outer surface of the dead bolt 42 contoured, as at 66, so as to approximate the inside surface of the tubular cross bar 12, bolt 42 frictionally engages and rides against such inside surface of the cross bar 12. In doing so, bolt 42 not only strengthens the cross bar 12 adjacent its end 32 but, more importantly, it also serves as a solid dead-bolt, when in place as shown in FIG. 1, in firmly retaining the leg 20 of the U-shaped shackle 14 therein. An appropriately shaped end plug 68 preferably is employed, both to seal the end 32 of the cross bar 12 and also to serve as a guide for the entry and withdrawal of the leg 20 via the opening 28 into the interior of the cross bar 12, as shown. Preferably, the end plug 90 is formed of metal or a hard plastic material and is secured in place, as for example by a suitable adhesive, not shown. Preferably, the end of the skin 16 is reduced somewhat in diameter near the end 32 so as to present a neat appearance and further to retain the plug 68 in place.
The bicycle lock 10 of the invention also features short stub ends at the respective ends 30 and 32 of the cross bar 12, resulting in a compact and sturdy design. The stub ends refer to that part of the cross bar 12, observe FIG. 1, which extend outwardly from the respective outer periphery of the pair of openings 26 and 28 to the respective ends 30 and 32 of the cross bar 12. The stub near the end 30 is about the size of the diameter of the leg 18, while the stub near the other end 32 is somewhat shorter, i.e., about one-half of the diameter of the leg 20. The end of the bent foot 22 is shown as extending somewhat beyond the end 30 of the cross bar 12. The skin 16 effectively covers the slight protrusion of the foot 22 beyond the end 30.
In FIG. 2, there is illustrated, in fragmentary section, a modification in the bicycle lock according to the invention and pertaining to the size of the stub ends, above discussed with reference to FIG. 1. A cross bar 110 is shown provided with an opening 112 near its end 114 designed to accommodate the bent foot 22 of the leg 18 of the shackle 14, all as previously described. The within illustrated stub end, i.e., the distance of the cross bar 110 extending outwardly from the outermost profile of the opening 112 to the end 114, is greater than the diameter of the leg 18 but is less than twice the diameter thereof. Consequently, in this embodiment, the end of the bent foot 22 does not even reach the end 114 of the cross bar 110, much less protruding therefrom.
The Embodiment of FIGS. 5-6
A second preferred embodiment of an improved locking device according to the invention is illustrated in FIGS. 5-6. Also in this embodiment, a locking mechanism 70 is mounted in a side of the tubular cross bar 12 and within the hole 36 formed therein near its end 32. The design of the lock 70 is similar to that of the lock 34 shown in and described with reference to FIGS. 1-4. The lock 70 has, however, been strengthened even further against the forceful removal of the shackle 14 from the tubular cross bar 12.
Locking mechanism 70 essentially comprises a lock cylinder 72 provided with a rib 74 designed to secure the lock cylinder 72 within the tubular cross bar 12, a first dead bolt member 76, that is cresent shaped in cross section and designed for limited positive axial displacement, which member 76 is similar to the deadbolt 42 of FIGS. 1-4, a second elongated guide member 78, complementary to the first dead bolt member 76 and provided with a bore 80 to receive the lock cylinder 72, and a cam 82, which is identical to the cam 46, operatively coupling the lock cylinder 72 to the dead bolt member 76 so as to impart thereto the same limited positive axial displacement between its two operative positions as described above with reference to FIGS. 1-4.
The cam 82 also is formed with a cutout 84 designed to receive a protruding operative part 86 of a cylindrical member 88. Member 88 also incorporates a spring 90 which functions just like the spring 52.
The elongated guide member 78 is provided with a pair of guide edges 92, 94 to facilitate the limited positive axial displacement of the first dead bolt member 76 relative thereto. A bottom flat surface 96 of the first dead bolt member 76 is designed frictionally to slide over a flat bed 98 formed in the second elongated guide member 78 in between its guide edges 92 and 94. It will be appreciated, especially when viewing FIG. 6, that the outer peripheries 100 and 102 respectively, of the first and second members 76 and 78 are both contoured so as to approximate the inner surface of the tubular cross bar 12 and, that the cross section of the combined members 76 and 78 substantially fills up the hollow space inside the tubular cross bar 12.
In the wall of the bore 80 formed in the second elongated guide member 78, there is provided a channel 104 which is designed to accommodate therein the rib 74 of the lock cylinder 72, securing thereby the lock cylinder 72 in and to the surrounding second guide member 78. Due to the combined effects of the rib 74 extending into the channel 104 of the member 78, both the lock cylinder 72 and the elongated guide member 78 are secured to one another as well as within the cross bar 12 against displacement therein. By inserting and turning a key, not shown, into the lock cylinder 72, in a way identical to that shown in and described with reference to FIGS. 1-4, the first dead bolt member 76 is caused to be displaced axially between its first operative position illustrated in FIG. 6, extending into the transverse cut 24 of the leg 20 of the U-shaped shackle 14, as shown in FIG. 1, and a second operative position, not shown in FIG. 6, in which it is withdrawn from the transverse cut 24.
The Embodiment of FIGS. 7-8
A third preferred embodiment of an improved locking device according to the invention is illustrated in FIGS. 7-8. Also in this embodiment, a locking mechanism 120 is mounted in the side of the cross bar 12 and within the hole 36 formed therein near its end 32. The design of the lock 120 is similar to that of the lock 70 shown in and described with reference to FIGS. 5-6.
The locking mechanism comprises a lock cylinder 122, a cylindrical member 124 formed with a cresent-shaped protruding part 126, and a cam 128 formed with a cresent-shaped cutout 130 designed to accommodate the operative part 126. Member 124 also incorporates a compression spring 132 and a circular depression 134 formed about midway in its periphery, substantially as shown. Cam 128 is designed to ride within a transverse cut 136 formed in the underside of dead bolt member 138 and axially displace the same within the channel of a second member 140, substantially as described with reference to the embodiment illustrated in FIGS. 5-6. Member 140 also is provided with a bore 142 designed to receive the lock cylinder 122 therein. The securing of the various parts of the locking mechanism 120 to each other and within the cross bar 12 is herein effected with the aid of a screw 144 designed to pass through a first bore 146 formed in member 140, and a second bore 148 formed in the lock cylinder 122, with the pointed end 150 of the screw 144 coming to rest in the depression 134 of the cylindrical member 124. An end plug 152 is provided to close off the end 32 of the cross bar 12. Plug 152 differs from the end plug 68 in that it does not also serve as a guide for the entry of the leg 20, which function is now assumed by the member 140.
FIGS. 9-11 illustrate bicycle locks in fragmentary perspective and according to the invention in which the cross bars thereof are formed with different shapes and are shown without any skin covers. For example, in FIG. 9 a cross bar 54 of rectangular shape is illustrated, while FIG. 10 illustrates a cross bar 156 of oval shape, and FIG. 11 a cross bar 158 of octogonal shape. FIGS. 12-13 illustrate, in cross section, still further shapes for a cross bar, namely a pentagonal and a hexagonal shape, respectively. In each instance, the internal shape of the respective cross bar can be tubular or, if desired, it can match its respective outer shape. If the latter, then of course the locking mechanism mounted therein also need be reshaped to be properly accommodated therein.
Thus, it has been shown and described an improved locking device for securing a bicycle or the like to a fixture, which device satisfies the objects and advantages set forth above.
Since certain changes may be made in the present disclosure without departing from the scope of the present invention, it is intended that all matter described in the foregoing specification or shown in the accompanying drawings, be interpreted in an illustrative and not in a limiting sense. | An improved bicycle lock, featuring a U-shaped shackle, a cross bar and means for securing one to the other, is disclosed. The means for securing the shackle to the cross bar also functions as a fulcrum, permitting a tilting movement between the two parts, required in assembling and dissassembling them. The means further includes a locking mechanism removably mounted in the cross bar in between the shackle's legs, and features a dead bolt. The cross bar extends beyond the shackle's legs less than twice the diameter of one of those legs, resulting in a compact and sturdy design. A plastic cover encloses at least the cross bar and is preferably formed of two parts slidably fitted over the cross bar, with means for securing the two parts to one another. Preferably, an environmental protection means is provided for the locking mechanism. | 8 |
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