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CROSS REFERENCE TO RELATED APPLICATION
The present application is related to U.S. patent application Ser. No. 891,043 of KLAUS SOMMER and HERMANN WEBER, filed Mar. 28, 1978 and entitled "N-SULFO ALKANE AMINO ALKANE PHOSPHONIC ACIDS AND THEIR ALKALI METAL SALTS AND A PROCESS OF PRODUCING SAME" and to Application Ser. No. 891,143 of KLAUS SOMMER, HERMANN WEBER, AND WILHELM SPATZ filed Mar. 28, 1978 and entitled "PROCESS OF PRODUCING N-SULFO ALKANE AMINO ALKANE PHOSPHONIC ACIDS AND THEIR ALKALI METAL SALTS" now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a novel, advantageous, and economic process of producing N-sulfo alkane amino alkane phosphonic acids and their water-soluble salts, to novel compounds obtained by said process, to compositions containing same, and to methods of using such compositions.
2. Description of the Prior Art
U.S. patent application Ser. No. 891,043 of KLAUS SOMMER and HERMANN WEBER discloses novel and highly advantageous N-sulfo alkane amino alkane phosphonic acids and their water-soluble salts. According to said application, such compounds are prepared by reacting an alkali metal salt of an amino alkane phosphonic acid in an alkaline solution with an alkali metal salt of a halogen or hydroxy substituted alkane sulfonic acid in a molar proportion between about 1:1 and about 1:2 of phosphonic acid reactant to sulfonic acid reactant, while heating. To carry out this process it is usually necessary to heat the reaction mixture to boiling under pressure at a temperature between about 180° C. and about 240° C.
SUMMARY OF THE INVENTION
It is one object of the present invention to provide a simple, effective, and economic process of producing N-sulfo alkane amino alkane phosphonic acids and their water-soluble salts which process does not require heating to temperatures of 100° C. and even higher.
Another object of the present invention is to provide novel and highly advantageous N-sulfo alkane amino alkane phosphonic acids and their water-soluble salts.
A further object of the present invention is to provide compositions containing novel N-sulfo alkane amino alkane phosphonic acids and their water-soluble salts.
Still another object of the present invention is to provide a method of using novel N-sulfo alkane amino alkane phosphonic acids and their water-soluble salts as sequestering agents which form complex compounds with bivalent and polyvalent metal ions so that they are useful in all instances in which effective complex-forming ability is required.
In principle, the novel and advantageous process according to the present invention comprises the step of reacting alkali metal salts of amino alkane phosphonic acids of the following formula ##STR1## in which
R 1 indicates hydrogen, alkyl with 1 to 11 carbon atoms, especially methyl or ethyl, aryl, especially phenyl, tolyl, or chloro phenyl, aralkyl, especially benzyl, cycloalkyl, especially cyclohexyl, amino alkylene with 2 to 5 carbon atoms, especially amino methylene CH 2 NH 2 , hydroxy alkylene, especially hydroxy methylene CH 2 OH or hydroxy ethylene C 2 H 4 OH, carboxy alkylene, especially carboxy methylene CH 2 .COOH, or a lower alkylene phosphonic acid group, especially the ethylene phosphonic acid group C 2 H 4 .PO 3 H 2 ;
R 2 indicates hydrogen or the phosphonic acid group PO 3 H 2 ; and
R 3 indicates hydrogen methyl, or a lower alkylene phosphonic acid group, especially the methylene phosphonic acid group CH 2 .PO 3 H 2
in an alkaline medium with an inner ester of a hydroxy alkane sulfonic acid, i.e. a sultone of the formula ##STR2## in which
R indicates alkyl with 3 to 20 carbon atoms.
Preferred sultones of this type are the following:
1,3-Propane sultone,
1,3-butane sultone,
1,4-butane sultone,
1,3-hexane sultone,
1,3-dodecane sultone,
1,3-heptadecane sultone,
1,4-tetradecane sultone,
3-methyl-2,4-heptane sultone,
2,2-dimethyl-1,3-hexane sultone,
2,5-hexane sultone
and the like sultones.
In general, any amino alkane phosphonic acids which contain at the amino group at least one hydrogen atom capable of being substituted by a sulfo alkane group and which correspond to the above given formula have proved to be suitable phosphonic acid reactants. Preferred reactants are, for instance, the sodium or potassium salts of the following amino alkane phosphonic acids:
Amino methane phosphonic acid,
amino methane diphosphonic acid,
N-methyl amino methane diphosphonic acid,
imino-bis-(methane phosphonic acid),
1-amino ethane-1,1-diphosphonic acid,
1-amino propane-1,1-diphosphonic acid,
phenyl amino methane diphosphonic acid,
2-carboxy-1-amino ethane-1,1-diphosphonic acid,
1-amino propane-1,1,3-triphosphonic acid,
1,2-di-amino ethane-1,1-diphosphonic acid,
3-hydroxy-1-amino propane-1,1-diphosphonic acid,
1-hydroxy-3-amino propane-1,1-diphosphonic acid,
and the like phosphonic acids.
The process according to the present invention has the advantage over the processes disclosed in Patent Application Serial No. 891,043 that the sultones react quite readily with the amino phosphonic acids according to the following reaction equations whereby the sultone ring is split up: ##STR3##
Of course, in place of the amino methane mono- and diphosphonic acids and the amino bis(methane phosphonic acid) and of the 1,3-propane sultone, there can be used other amino alkane phosphonic acids and alkane sultones.
The reaction is preferably carried out by dissolving the amino alkane phosphonic acid in an alkaline medium, the pH-value of which is at least 9.0 and preferably between 10.0 and 12.0, and adding drop by drop thereto the respective alkane sultone. Thereafter, the reaction mixture is heated at a temperature which is below 100° C., preferably at a temperature between about 60° C. and about 90° C. for about one hour to two hours so as to achieve complete reaction.
The novel phosphonic acid compounds according to the present invention are excellent complexing or sequestering agents with respect to bivalent or polyvalent metal ions. Thus they can be employed with advantage in all those instances where a complexing or sequestering power is required. More particularly, the novel compounds excel by their high resistance to hydrolysis even at a high temperature. Due thereto they can be employed in all aqueous media in which temperatures exceeding 100° C. are encountered and in which the hardness causing agents present therein cause trouble or in which the effect of polyvalent metal ions is to be excluded. More particularly they have proved to be useful, as stated above, for softening hard water, as additives to textile treatment baths, in paper manufacture, in tanning baths, and for other purposes.
The novel phosphonic acid compounds are also useful for stabilizing the hardness of water when added in substoichiometric amounts, i.e. for carrying out the so-called "threshold processes."
The novel phosphonic acid compounds according to the present invention combine the properties of compounds which contain sulfonic acid groups with the properties of compounds containing amino groups. Especially advantageous is the exceedingly high solubility of the free acids in aqueous media, a property which most of the heretofore known amino phosphonic acids do not possess. Thus at least amounts of 100 g. of the compounds described hereinafter in the examples are soluble in 100 cc. of aqueous medium.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following examples serve to illustrate the present invention without, however, being limited thereto.
EXAMPLE 1
47.8 g. of amino methane diphosphonic acid are dissolved with 70 g. of potassium hydroxide in 200 cc. of water while stirring vigorously. 32 g. of 1,3-propane sultone, dissolved in 75 cc. of ethanol or isopropanol, are added drop by drop thereto at a temperature between 40° C. and 50° C. while continuing vigorous stirring. Thereupon, the reaction mixture is heated at 80° C. to 90° C. for one hour. After cooling, the reaction solution is adjusted to slightly acid reaction by the addition of hydrochloric acid. Any precipitated unreacted amino methane diphosphonic acid is removed by filtration. The filtered solution is treated with a cation exchange agent. After evaporating the treated solution to dryness and washing the residue with ethanol, the N-(sulfo propane) amino methane diphosphonic acid is obtained. Said acid is contaminated by a small amount of N-bis-(sulfo propane) amino methane diphosphonic acid. The yield is 89.5% of the theoretical yield. The acid exhibits a lime-binding power of 25 g. of Ca for 100 g. of acid.
Analysis:
Found: C: 15.6%, N: 4.1%, P: 19.1%, S: 10.9% Calculated: C: 15.34%, N: 4.47%, P: 19.78%, S: 10.24%.
EXAMPLE 2
47.8 g. of amino methane diphosphonic acid, 84 g. of potassium hydroxide, and 64 g. of 1,3-propane sultone are reacted in 100 cc. of ethanol as described hereinabove in Example 1. Thereby, 112 g. of N,N-bis-(sulfo propane) amino methane diphosphonic acid are obtained. The acid has a lime-binding power of 18.5 g. Ca for 100 g. of acid. Yield: 93.5% of the theoretical yield.
Analysis:
Found: N: 3.5%, P: 14.6%, S: 14.8%. Calculated: N, 3.22%, P: 14.23%, S: 14.73%.
EXAMPLE 3
47.8 g. of amino methane diphosphonic acid are suspended in 150 cc. of water. 140 g. of a 50% potassium hydroxide solution are added drop by drop thereto. Thereafter, a solution of 36 g. of 1,3-butane sultone in 75 cc. of ethanol are added drop by drop thereto while stirring vigorously. The reaction mixture is worked up as described in Example 1 and yields N-(sulfo butane) amino methane diphosphonic acid.
Yield: 91.5%.
Analysis:
Found: N: 4.0%, P: 18.1%, S: 10.5%. Calculated: N: 4.28%, P: 18.93%, S: 9.79%.
EXAMPLE 4
The procedure is the same as described in Example 3 whereby, however, 36 g. of 1,4-butane sultone are used as sultone reactant. N-(sulfo butane) amino methane diphosphonic acid is obtained in a yield of 86.3% of the theoretical yield.
EXAMPLE 5
51. g. of 1-amino ethane-1,1-diphosphonic acid are dissolved together with 50 g. of sodium hydroxide in 40 cc. of water. 45 g. of 1.3-hexane sultone dissolved in 80 cc. of ethanol or isopropanol are added drop by drop to said phosphonic acid solution at a temperature between 40° C. to 60° C. while stirring vigorously. Thereafter, the reaction mixture is kept at the boiling temperature for about one hour. After acidifying the reaction solution, treating it with a cation exchange agent, and concentrating by evaporation the reaction solution, the N-(1-sulfo hexane)-1-amino ethane-1,1-diphosphonic acid is obtained.
Yield: 89.2% of the theoretical yield.
Analysis:
Found: N: 3,9%, P: 16.3%, S: 8.9%. Calculated: N: 3.79%, P: 16.78%, S: 8,68%.
EXAMPLE 6
The procedure is the same as described in Example 5, whereby, however, 68 g. of 1,3-dodecane sultone are used in place of 1,3-hexane sultone. Yield of the resulting N-(1-sulfo dodecane)-1-amino ethane-1,1-diphosphonic acid: 87.3% of the theoretical yield.
Analysis:
Found: N: 3,4%, P: 13.2%, S: 7.6%. Calculated: N: 3.09%, P: 13.66%, S: 7.07%.
EXAMPLE 7
47.8 g. of amino methane diphosphonic acid are suspended in 100 cc. of water and 112 g. of a 50% potassium hydroxide solution are added thereto. 65 g. of 1,4-undecane sultone, dissolved in 80 cc. of methanol, are added drop by drop thereto while stirring vigorously. Thereby, the temperature slowly increases to 80° C. The reaction mixture is kept at said temperature for 30 minutes. The pH of the resulting solution is adjusted to a pH of 3.0 to 4.0. Any precipitated unreacted amino methane disphosphonic acid is filtered off and the filtrate is treated with a cation exchange agent. After evaporating the resulting solution to dryness in a water-jet vacuum, 78 g. of N-(1-sulfo undecane) amino methane diphosphonic acid are obtained.
Analysis:
Found: N: 3.1%, P: 14.1%, S: 7.7%. Calculated: N: 3,29%, P: 14.56%, S: 7.54%.
EXAMPLE 8
The procedure is the same as described in Example 7 whereby, however, 75 g. of 1,4-tetradecane sultone are added as sultone reactant in place of 65 g. of 1,4-undecane sultone. 83 g. of N-(1-sulfo tetradecane) amino methane diphosphonic acid are obtained.
Analysis:
Found: N: 3.2%, P: 12.9%, S: 7.1%. Calculated: N: 3.00%, P: 13.25%, S: 6.86%.
EXAMPLE 9
66.8 g. of phenyl amino methane diphosphonic acid and 50 g. of sodium hydroxide are dissolved in 300 cc. of water. 32 g. of 1,3-propane sultone dissolved in 75 cc. of ethanol or isopropanol, are added drop by drop thereto and the mixture is heated as described hereinabove in the preceding examples. Any unreacted phenyl amino methane diphosphonic acid is precipitated by acidifying with dilute hydrochloric acid. After filtration, a solution of the sodium salt of the corresponding N-(sulfo propane) phenyl amino methane diphosphonic acid is obtained. A sample of said solution is treated with a cation exchange agent and yields, on evaporation to dryness, the N-(sulfo propane) phenyl amino methane diphosphonic acid.
Analysis:
Found: C: 31.4%, N: 3.4%, P: 15.4%, S: 8.7%. Calculated: C: 30.85%, N: 3.60%, P: 15.91%, S: 8.24%.
EXAMPLE 10
The procedure is the same as described in the preceding example whereby, however, 36 g. of butane sultone are added as the sultone reactant in place of 1,3-propane sultone. A solution of the sodium salt of the corresponding N-(sulfo butane) phenyl amino methane diphosphonic acid is obtained.
EXAMPLE 11
On reacting a solution of 51 g. of 1-amino ethane-1,1-diphosphonic acid and 70 g. of potassium hydroxide in 300 cc. of water with a solution of 33 g. of 1,3-propane sultone in 50 cc. of methanol, a solution of the potassium salt of N-(3-sulfo propane)-1-amino ethane-1,1-diphosphonic acid is obtained. After treating said solution with a cation exchange agent, evaporating the treated solution to dryness, and washing the residue with mthanol, the corresponding N-(3-sulfo propane)-1-amino ethane 1,1-diphosphonic acid is obtained.
Yield: 90.3% of the theoretical yield. Analysis:
Found: C: 18.9%, N: 4.4%, P: 18.4%, S: 10.3%. Calculated: C: 18.35%, N: 4.28%, P: 18.93%, S: 9.80%.
The following Table illustrates the preparation of other N-(sulfo alkane) amino alkane phosphonic acids which can be produced according to the preceding example. In said Table there are mentioned the phosphonate and sulfonate reactants and the resulting reaction products and the method and example according to which the reaction products are obtained.
__________________________________________________________________________ PreparedPhosphonate Sultone Reaction According toExampleReactant Reactant Product Example No.__________________________________________________________________________12 Amino methane 1,3-Heptadecane sultone N-(sulfo heptadecane) amino 1diphosphonate methane diphosphonic acid13 Amino methane 3-methyl-2,4-heptane N-(sulfo-3-methyl heptane) 3diphosphonate sultone amino methane diphosphonic acid14 Amino methane 2,2-dimethyl-1,3- N-(sulfo-2,2-dimethyl hexane) 3diphosphonate hexane sultone amino methane diphosphonic acid15 N-methyl amino methane 1,3-propane sultone N-methyl-N-(sulfo propane) 1diphosphonate amino methane diphosphonic acid16 Imino bis-(methane 1,3-butane sultone N-(sulfo butane) imino bis- 3phosphonate) (methane phosphonic acid)17 1-Amino propane-1,1-diphosphonate 1,3-propane sultone N-(sulfo propane)-1-amino 1 propane-1,1-diphosphonic acid18 2-Carboxy-1-amino ethane- N-(sulfo butane)-2-carboxy-1- 41,1-disphosphonate 1,3-butane sultone amino ethane-1,1-diphosphonic acid19 1-Amino propane-1,1,3- 1,4-butane sultone N-(sulfo butane)-1-amino propane- 3triphosphonate 1,1,3-triphosphonic acid__________________________________________________________________________
Compounds in which the substituent R 1 together with the substituent R 3 is alkylene with 3 to 5 carbon atoms and thus forms an azacycloalkane ring with the group ##STR4## are also obtained according to the processes described hereinabove and in the examples. Thus, for instance, azacycloheptane-2,2-diphosphonic acid yields by reaction, for instance, with 1,3-propane sultone, as described hereinabove, the corresponding N-(sulfo propane) azacycloheptane diphosphonic acid. Other N-(sulfo alkane) azacycloalkane phosphonic acids are produced in a corresponding manner.
Of course, many changes and variations in the reactants used and the reaction conditions, duration, temperature, and pressure, in the manner in which the reaction solution is worked up, purified, and converted to the N-sulfo alkane amino alkane phosphonic acid or its alkali metal salts and the like may be made by those skilled in the art in accordance with the principles set forth herein and in the claims annexed thereto.
Preferably strongly acid cation exchange agents such as, for instance, sulfonated polymerization products of styrene, divinylbenzene, and the like, are used for producing the free sulfo alkane amino alkane phosphonic acids of the present invention, for instance, sulfonated polymers of styrene or divinylbenzene as they are known under the trademark "Duolite C25" of the firm Diamond Alkali Co., "Amberlite IR 112 and IR 120" of the firm Rohm & Haas Co., "Dowex 50" of the firm Dow Chemical Co., "Levatit S100" of the firm Bayer A. G., and others.
The novel N-(sulfo alkane) amino alkane phosphonic acids and their alkali metal salts as well as their reaction solutions or the mother liquors obtained after separating the unreacted crystalline phosphonic acids are used, as stated above, as additives to aqueous media to eliminate or suppress the disturbing and obnoxious effects of hardness-forming agents present therein or to exclude the action of polyvalent metal ions in said media. On account of their high sequestering power they can advantageously be used for preventing scale and deposit formation in aqueous systems and thus are advantageously employed, for instance, in textile bleaching baths, in water used for sterilizing cans, for preventing formation of resinous deposits in the manufacture of paper, and the like.
The phosphonic acids according to the present invention can also be used as sequestering, complexing, and/or chelating agents for other purposes, for instance, as described in U.S. Pat. No. 3,860,391 in peroxide bleaching baths, and in U.S. Pat. Nos. 3,833,517 and 3,954,401 in baths for the treatment of cellulose fiber materials and for other uses for which phosphonic acids have been used heretofore. If desired, the alkali metal or ammonium salts or the salts with organic amines or solutions thereof can also be used in place of the free acids. The salts can be prepared, for instance, by neutralizing the acids with the calculated amounts of alkali metal hydroxides, ammonia, or organic amines.
The following examples illustrate the manner in which the sulfo alkane amino alkane phosphonic acids according to the present invention can be employed without, however, limiting their usefulness to these examples.
EXAMPLE 20
The following test was carried out in an upright autoclave of a capacity of 10 liters of water. The autoclave was operated at about 4 atmospheres gauge and at a temperature of 140° C. The autoclave was charged with conventional tin plated cans.
Tap water of the following composition was used for sterilization:
______________________________________Total degree of hardness 25° German hardnessHardness due to carbonates 17° German hardnessChlorides 53 mg./l.Sulfates 85 mg./l.Free carbon dioxide 40 mg./l.Bound carbon dioxide 125 mg./l.pH-value 7.2______________________________________
Before sterilization of the cans 5 cc. of a 30% solution of N-(sulfo propane)-1-amino ethane-1,1- diphosphonic acid were added to the water. Addition of said phosphonic acid resulted in keeping not only the sterilized cans but also the autoclave free of incrustations. The cans had a glossy and shiny appearance.
EXAMPLE 21
250 g. of bleached sulfite pulp known for its property of causing continuously difficulty on the paper machine due to resin deposition were beaten to a 3% suspension in water. The resulting shock suspension was ground in a Hollander beater to about 78° Schopper-Riegler, i.e. so as to form a well beaten pulp suitable for producing dense sheets of parchment-like paper. The pH-value of the resulting slurry was 6.0. Before starting beating, 0.5 kg. of the tetrasodium salt of N-(sulfo propane)-2-carboxy-1-amino ethane-1,1-diphosphonic acid were added to the slurry in the Hollander beater. After beating and refining, 0.8 kg. of the same phosphonic acid were admixed thereto.
When proceeding in this manner, no resinous deposits were observed on the walls of the Hollander beater and also not on the pipe lines and subsequently on the paper machine.
EXAMPLE 22
Treatment of water used for sterilization of cans.
Tin plated cans are placed into a 10 liter autoclave. Tap water of the following composition is used for sterilization of the cans:
______________________________________Total hardness 25° German hardnessCarbonate hardness 17° German hardnessChlorides 53 mg./1.Sulfates 85 mg./1.Free Carbon dioxide 40 mg./1.Bound carbon dioxide 125 mg./1.pH-value 7.2______________________________________
0,25 g./l. of N-(sulfo propane)-1-amino ethane-1,1-diphosphonic acid are added to the tap water. Sterilization is effected by heating to 140° C. at about 4 atmospheres gauge. Addition of the phosphonic acid compound inhibits scale and deposit formation on the sterilized cans as well as on the walls of the autoclave.
The same or similar results as described in Examples 20 to 22 were observed when using other N-sulfo alkane amino alkane phosphonic acids as obtained, for instance, according to Examples 1 to 19.
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N-(sulfo alkane) amino alkane phosphonic acids or their water-soluble salts are obtained by reacting an alkali metal salt of an amino alkane phosphonic acid with at least one hydrogen atom in the amino group which can be replaced by a sulfo alkane group, in an alkaline medium with an alkane sultone while heating.
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BACKGROUND OF THE INVENTION
This invention relates to a photovoltaic (PV) energy conversion device, specifically a thin film n/p or n/i/p heterojunction with graded carrier concentration, using semiconducting compounds from the I-III-VI 2 , I-III-VI-VII and I-VI 3 -VII series. It relates further to methods of manufacturing the cells, directed to producing a cell, especially an indium-tin-oxide (ITO)/n-CulnSe 2 /i-Culn x Se y I z /p-CulSe 3 cell, with relatively high efficiency, high stability, low cost, and low toxicity.
Photovoltaic cells offer the prospect of a more benign and renewable source of power than either fossil or nuclear systems. The criteria for a successful photovoltaic device are high energy conversion efficiencies, long-term stability and low cost. The high efficiency solar cells are based on monocrystal absorbers, for example, Si, GaAs, InP, and CdTe, which require high energy, labor, and highly purified materials. The less expensive amorphous Si cell is unstable and less efficient. CulnSe 2 meets the criteria of low cost, high efficiency, stability, and environmental safety. It has thus emerged as the most promising material for terrestrial and space applications. It is a direct band gap semiconductor with a low minority carrier diffusion length, a high absorption coefficient, and a steep absorption edge. These attributes permit fabrication of lightweight, low material-usage thin film cells; its radiation hardness ranks CulnSe 2 ahead of Si and GaAs for space use.
In the prior art, p-CulnSe 2 has been used in thin film Mo/p-CulnSe 2 /n-CdS/ZnO cells (p-CIS) by various workers. U.S. patents to Mickelson et al (1980) U.S. Pat. Nos. 4,335,266, 4,465,575; Kapur et al (1986) U.S. Pat. No. 4,581,108, Ermer et al (1989) U.S. Pat. No. 4,798,660 provide background information on the development of the p-CIS cell. Numerous deposition techniques have been employed, including: (a) selenization of Cu/In layers; (b) evaporation (thermal, electron-beam, sputtering or ion plating); (c) electrodeposition; (d) chemical spraying; (e) screen printing; (f) sintering; and (g) laser annealing. The description of these methods and the resulting films along with references are summarized by Zweibel et al (1989), Chopra and Das (1983). The key processes that have yielded high quality p-CIS films are co-evaporation of Cu, In, and Se, and selenization of electron beam deposited Cu and In layers. Although single junction efficiencies in the range of 14% have been recently reported, the sensitivity of cell performance to several processing steps and safety issues associated with some cell components continue to be of serious concern and have hindered its commercialization. For example:
(i) the toxicity of the CdS window component has been the primary deterrent in its terrestrial use (Cd and its compounds present health, safety and environmental hazards, e.g. Moskowitz et al (1990));
(ii) the Mo contacts to p-CuInSe 2 affect the mechanical stability (poor adhesion) and the performance of the cell, possibly due to the formation of a layered compound, MoSe 2 , at the interface. Mo is also toxic to some degree;
(iii) interdiffusion of Cu and Cd at the heterojunction interface can induce conductivity type inversion in thin films of p-CuInSe 2 which could undermine the cell stability, especially in radiative environments;
(iv) lattice mis-match of 1.2% between CuInSe 2 and CdS increases interface state density, leading to efficiency losses due to the associated recombination.
The n-CuInSe 2 material has not been employed in a thin film photovoltaic cell for two reasons: (a) first, the difficulties encountered in preparing non-resistive n-CuInSe 2 films, e.g. Thornton (1987) indicated that the deposition of In-rich films by reactive sputtering in H 2 Se medium led to In rejection; other workers have noted similar In rejection for the co-evaporation and in the e-beam deposition/selenization methods. Noufi et al (1987) reported the formation of highly compensated and resistive n-type films by co-evaporation. Similarly synthesized films were unsatisfactory even after vacuum annealing at high temperatures in the presence of Cd or In, according to Haneman (1990); and (b) the second reason was the lack of a highly conducting and transparent p-type window, as most wide bandgap materials, e.g. oxides, are n-type.
Nevertheless, high efficiency photoelectrochemical cells with n-CuInSe 2 single crystal were reported by Menezes et al (1983, 1984, 1986) and by Cahen (1984). Our U.S. Pat. No. 4,601,960 (1986) describes the first n-CuInSe 2 photoelectrochemical cell that was stabilized from corroding in the electrolyte by inducing the growth of a new semiconducting interphase from the corrosion products. The n-CuInSe 2 single crystal based solar cell with a CuISe 3 interfacial film was 12.2% efficient and stable. An energy difference between the work functions of CuInSe 2 and CuISe 3 suggested the possibility of a buried p/n heterojunction between the two materials. Although our approach at surface stabilization was reproduced by various other workers, no further evidence of a solid state junction was reported. Thus, no solid state cell has been constructed primarily because (c) large single crystal CuInSe 2 substrates are difficult to fabricate and impractical for scale-up and (d) since CuInSe 2 thin films tend to corrode and peel off the substrate during surface conversion in the electrolyte.
The uncertainties regarding the existence of a solid state junction persisted because of the above mentioned difficulties in verifying the concept of a buried p/n junction. These difficulties also prevented the construction of a practical photoelectrochemical cell. In general, the utility of photoelectrochemical cells is limited by several engineering constraints:
(e) Inflexible cell design;
(f) Susceptibility to leaks and corrosion at the various inherent solid/liquid interfaces;
(g) Uncertain long-term stability of the electrolyte/semiconductor interface in hostile environments; and
(h) Need for expensive bulk (thick) single crystal or polycrystalline CuInSe 2 substrates which are not economical in terms of material and energy usage, and unsuitable for large area applications (Single crystal grain size rarely exceeds 2 cm 2 ).
SUMMARY OF THE INVENTION
Accordingly, the object of this invention is to provide a new lightweight, large area thin film solar energy conversion device with compatible, non-hazardous components and potentially lower cost, higher efficiency and stability than prior art. The new device combines the optimum PV properties of CulnSe 2 , the advantages of a thin film cell configuration and the non-toxic cell components synthesized in our previous photoelectrochemical cell and eliminates the disadvantages of the thin film p-CIS and single crystal or polycrystalline n-CIS photoelectrochemical cells. The preferred embodiment consists of ITO, n-CulnSe 2 absorber, Culn x Se y I z transition layer, p-CulSe 3 window, transparent ohmic contact, and antireflection coating. The invention is distinctly different from either the p-CIS thin film cell or n-CIS photoelectrochemical cell and offers several advantages over the prior art.
Distinctions/Advantages over Thin Film p-CulnSe 2 /n-CdS Cell (U.S. Patents to Mickelson et al U.S. Pat. Nos. 4,335,266, 4,465,575; Kapur et al U.S. Pat. No. 4,581,108; Ermer et al U.S. Pat. Nos. 4,798,660, 4,611,091). These include:
(a) n-CulnSe 2 absorber which may be more efficient due to the higher mobility of electrons;
(b) Two new environmentally-acceptable window materials to replace the highly toxic CdS (window) component. Thus the production of hazardous materials and waste is minimized;
(c) Perfect lattice match between CulnSe 2 and Culn 2 ISe 3 layers, which minimizes lattice distortion and interface state density, and contributes to high efficiency;
(d) More stable heterojunction due to similar components (except I) on both sides of the junction;
(e) ITO back contact provides better adhesion to n-CulnSe 2 as compared to that between p-CulnSe 2 and Mo in the prior art;
(f) An innovative approach: a simple, inexpensive, room temperature electrochemical method to form a n/p heterojunction, in which surface layers of n-CulnSe 2 absorber film are electrochemically converted to a p-type window; this approach used for the preferred embodiment minimizes energy usage and material waste, eliminates expensive vacuum deposition equipment, waste disposal, and simplifies large scale manufacturing; and
(g) Tailored heterostructure, n + -n-i-p-p + : the combination of ITO back contact and the electrochemical surface conversion create regions of high carrier density adjacent to ohmic contacts and a region of high resistivity in the space charge region.
Distinctions/Advantages over the photoelectrochemical or solid state n-CIS prior art, U.S. Pat. No. 4,601,960 to Menezes et al. These include:
(a) ITO back contact replaces the toxic Hg-In amalgam;
(b) Intrinsic layer, e.g. Culn x Se y I z , not specified in the prior art;
(c) Transparent conducting oxide front contact to the p-layer since Au forms a barrier with p-CulSe 3 and also reflects a large fraction of the incident light;
(d) Eliminates the etching steps, required to remove damaged layers from the mechanically sliced single crystal or polycrystalline wafers; also reduces material waste;
(e) Thin film (<5 μm thick) substrate is cost effective in terms of CulnSe 2 material and energy usage relative to the thick (>200 μm) single crystal or polycrystalline substrate;
(f) Amenable to large area fabrication (m 2 for thin film as compared to mm 2 for single crystal);
(g) Eliminates leaks and sealing problems inherent in photoelectrochemical cells;
(h) Amenable to flexible thin film technology;
(i) Amenable to lightweight space technology; and
(j) Low cost processing of the thin film photoactive layer relative to single crystal or polycrystalline bulk materials.
Further advantages of this invention will become apparent from consideration of the drawings and ensuing description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a precursor part, comprising a substrate, an ITO film and, an n-type film;
FIG. 2 is a sectional schematic view of a thin cell embodying components of the present invention including the precursor part, a transition layer, a p-type window layer, a transparent conducting oxide, a metal grid contact, and antireflection coating. The dotted lines representing the interfaces between the layers indicate diffuse interfaces due to composition gradients;
FIG. 3 shows the precursor part 1 with edges encapsulated with an inert insulating material, for immersion in an electrolyte;
FIG. 4 shows a laboratory scale electrochemical cell to convert the surface of n-CuInSe 2 surface to i-CuIn X Se Y I Z /p-CuISe 3 ;
FIG. 5 shows typical current-voltage characteristics of the sample in FIG. 1, before and after surface conversion; and
FIG. 6 shows an alternate electrochemical cell for converting a large sample, embodiment of FIG. 1 in the liquid electrolyte.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows the precursor part 11 of the cell, comprising a substrate 12, a back ohmic contact 13, and the n-type photoactive film 14. The substrate 12 serves as a backing to support the electroactive layers of the cell. Depending on the application and the method used for depositing the active layers, the substrate 12 may be a rigid or flexible and/or transparent, lightweight, insulating material, e.g. glass, alumina, plastics. For example, a front-wall illuminated cell will require a transparent glass substrate with an antireflection coating, while a high specific-power cell for space surface power application will use a lightweight, flexible, plastic substrate.
Layer 13 serves as the ohmic contact to the absorber (n-CuInSe 2 ) layer 14. The deposition method used to synthesize the CuInSe 2 layer has a direct bearing on selection of the ohmic contact material. In conjunction with the selenization (of Cu/In alloy) method described by Basol et al (1989), ITO is the preferred back-ohmic contact. ITO coated glass substrates are commercially available. ITO may be deposited by sputtering or other vacuum methods. Another indium compound or an indium alloy or another group III element may be substituted for ITO. Layer 13 is one of the key elements of this invention. Besides providing an ohmic contact layer 14, layer 13 provides better mechanical adhesion between layers 12 and 14 relative to the Mo contact in the prior art; more importantly it induces n-type conductivity and graded doping in the layer 14. Note that another back-contact material, e.g. Mo, can be substituted in conjunction with other deposition techniques, e.g. co-evaporation, where the deposition rate of the elements can be precisely controlled to yield the desired stoichiometry and grading in the CuInSe 2 layer.
Layer 14 is the photoactive component of the cell selected from the I-III-VI 2 series, e.g. CuInSe 2 . This layer is synthesized by selenization of I-III precursor alloy. Basol et al (1989) have described this method in the prior art for synthesis of p-CuInSe 2 films on Mo coated substrates. The modification in this invention includes an ITO coated substrate, a Cu/In ratio of 0.95-1.00 in the film and thickness between 3-5 microns. By maintaining the ratio of depositing source metals, i.e. a Cu/In ratio close to 1, an average ratio of about 0.9 will be obtained in the deposit. The diffusion of In from layer 13 into the CuInSe 2 film during its synthesis alters the film stoichiometry by decreasing the Cu/In ratio, producing n-type conductivity and a composition gradient in the film. The region of layer 14 adjacent to layer 13 will thus have a higher dopant concentration (n + ), enabling a better ohmic contact with layer 13, while the outer layers with low impurity concentration will remain conveniently resistive. It should be pointed out that decreasing the Cu/In ratio alone leads to segregation of the InSe phase leading to inhomogeneous, highly resistive material. The ITO back contact is crucial to the engineering of the film conductivity. Since the i-Culn x Se y I z /p-CuISe 3 layers are grown by electrochemically anodizing a portion of layer 14, this film has to be thicker than prior art p-CIS films.
The inventive device of the present example is schematically represented in FIG. 2. Layer 15 is the transition layer between two semiconductors, i.e. n-CuInSe 2 and p-CuISe 3 with well defined composition and conductivity type. Layer 15 is a quaternary material, I-III-VI-VII, comprising elements from both adjacent layers 14 and 16. In the present example layer 15 is believed to be a high resistivity, nearly intrinsic material, CuIn x Se y I z , with a graded composition, such that, x decreases while y and z increase away from layer 14 relative to the Cu concentration. This layer serves as a low doped material in the depletion region.
Layer 16 is the p-type semiconductor window, selected from the series I-VI 3 -VII, which in the present example is p-CuISe 3 . It contains excess Se which dopes it p + to avoid series resistance near the front contact. Layers 15 and 16 together are less than a micron thick, to increase transmission of the incident light to the absorber, 14. These layers serve as the heterojunction partner for the n-type absorber layer 14 creating a diffusion potential within the heterojunction. The n/i/p heterojunction is annealed for approximately 10 min in air at about 150° C.
A highly conductive transparent electrode 17 is used to facilitate current collection from the p-type layer 16. It may be made up of a transparent conducting oxide such as ZnO or SnO 2 . Since these oxides are n-type, they have to be substantially degenerate or highly doped to eliminate the formation of a rectifying junction with the p-CuISe 3 layer 16. The need for layer 17 depends on the morphology and the conductivity of layer 16, which in turn depends on the deposition process employed. A grid of contact metal, 18 e.g. Cu, Au, or Al may supplement layer 17 or be used directly over layer 16 if this layer 16 is highly conducting. The metal grid 18 may be deposited by evaporation, sputtering, or electroplating. Conducting metal power output wires 19 are conductively bonded to contacts 13 and 17 (or 18). The inventive device can operate in either front-wall (illuminated though layer 13) or backwall (illuminated through layer 16) mode if transparent ohmic contacts are employed. A commercial antireflection coating 20 such as `Corning` glass or oxide of Si, Al, or Ta, deposited on the outermost cell component, 12, 17 or 18, that is exposed to illumination 28, completes the device.
Prior to electrochemical surface conversion the precursor electrode 11 is prepared, as shown in the in the part 21 modification of FIG. 3. The exposed edges of contact 13 and a portion of the connecting wire 19 are encapsulated with a removable insulating lacquer or wax 22, e.g. Turco mask, photoresist, that is chemically inert in the electrolyte.
The insulated precursor electrode 21 is then immersed in the electrochemical cell 23 containing a liquid electrolyte 24, comprising approximately 2M I-, 50 mM I 2 , 50 mM Cul, and 4M HI, so that the surface of layer 14 is in contact with the electrolyte 24 as shown in FIG. 4. The electrolyte composition is similar to the prior art, U.S. Pat. No. 4,601,960 to Menezes (1986), but the procedure and the concentrations are modified. The electrolyte container 25 is preferably a rectangular quartz cell or a conventional cell provided with a quartz window of area that is greater than the exposed surface of layer 14. A counter electrode 26 and a reference electrode 27, made of an inert metal or carbon, are included in the electrochemical cell 23. The reference electrode 27 sets the reference voltage for the electrode 21 at the redox potential (V R ) of the electrolyte. The cell photovoltage, V CELL , is given by the open-circuit voltage, V OC , of electrode 21 with respect to V R , under illumination. The cell is illuminated with solar or simulated white light 28 in order to produce anodic current in the n-type layer 14. The electrolyte 24 is de-aerated by bubbling nitrogen gas 29. The electrodes are connected to a potentiostat 30.
Layer 14 is photoanodized in electrolyte 24 by potentiostatically cycling the electrode between V R and V OC and/or holding it at a fixed potential between these two limits for 10-20 minutes, depending on the current density. A slow rate of film growth using low illumination (<100 W/cm 2 ) and low anodic current (<10 mA/cm 2 ) is preferred to reduce the rate of growth and improve the morphology of layer 15.
The quality and conversion of the layer 14 surface and the quality of the n/i/p junction are monitored in-situ by measuring the current(I)-voltage(V) output shown in FIG. 5. Curve I shows the dark I-V output. Any anodic current if observed in the dark is attributable to pin-holes or shunts in the layer 14. Curve II showing the initial I-V curve of the thin film 14 indicates a relatively poor quality junction between the thin film 14 and the electrolyte 24. Growth of layers 15 and 16 by photoanodization leads to an increase in photocurrent, photovoltage (V OC -V R ) and the fill factor, as shown in curve III. The dark current, curve IV, is also lower since the growth of layers 15 and 16 seals the pores in film 14. The electrode is then removed from the electrolyte, rinsed in distilled water, and dried with nitrogen gas. The encapsulant is removed by peeling off the wax or dissolving the photoresist in a solvent, e.g. acetone.
FIG. 6 shows an alternate electrochemical cell 31 for surface conversion using precursor electrode 21. This method may be scaled up for fabrication of large area cells. The steps of encapsulation and its removal are eliminated in this version. Electrode 21 is mounted on top of the container 25 filled with the electrolyte 24. Contact between the electrode surface and the electrolyte is attained by a capillary action. A soft plastic or rubber gasket 32 is inserted between the electrode and the top of the container 31. An inlet and an outlet to the container 25 are provided to enable electrolyte 24 circulation, deareation, or the elimination of air bubbles at the surface of the electrode 21. Layer 14 is illuminated from the bottom through a metal mesh counter electrode 26. With minor modification of the cell 31, bottom or side mounts for the electrode 21 can be implemented for convenience. For example, the current distribution can be optimized by changing the geometry of electrode 24. Thus the anodization can be performed galvanostatically, thereby eliminating the reference electrode 27.
CONCLUSIONS, RAMIFICATIONS AND SCOPE
It is evident from the above description that the inventive cell will provide highly efficient, reliable, low-cost photovoltaic energy conversion device for space missions or for terrestrial power systems. Alternate thin film deposition methods described in the reference by Chopra and Das (1983) may be used to synthesize the layers 14, 15, and 16. Prior art methods used to synthesize p-CulnSe 2 thin films, particularly those listed in the reference by Zweibel et al (1989), are incorporated in this patent by reference to synthesize layers 14, 15, and 16. The additional criteria in employing the prior art methods (except for co-evaporation) for synthesis of the n-CulnSe 2 layer 14, include replacing the Mo back contact with an ITO (or its analogues) contact 13 and maintaing the ratio of Cu/ln reactants close to one. Each of the prior art deposition processes used to synthesize CulnSe 2 thin films offer specific advantages and disadvantages. Preferences of one over the other will depend on the criteria or requirements of specific application of the device. For example, processing and cost advantages, and amenability to large area fabrication are important considerations for large scale terrestrial PV applications where electrodeposition is more appropriate. Electrodeposition can be used either to deposit the precursor Cu/ln films or the CulnSe 2 compound with appropriate modifications in the deposition parameters to produce an n-CulnSe 2 layer.
For space applications, where reliability, low weight and efficiency precede the cost factor, high quality n-CulnSe 2 thin films may be more effectively synthesized by using the technique of co-evaporation of the constituent elements, Cu, In, and Se, or the constituent compounds Cu 2 Se and In 2 Se 3 . This technique can be further adapted to sequentially synthesize layers 15 and 16 in an integrated evaporation system, comprising Cu, In, I, and Se sources. The vapor pressure of volatile materials like I and Se is lowered by keeping the I and Se sources at low temperatures. The I-source is shut off during synthesis of layer 14. All four sources are used to deposit layer 15. The in-source is shut off during deposition of layer 16. Since almost analogous elements constitute the three layers, the same chamber can be used to synthesize the heterojunctions in-situ thus minimizing fabrication costs, particularly for large area applications. The process parameters can be adjusted as required to produce the desired stoichiometry for each layer.
Similarly, an integrated system may be used to sputter deposit the three layers 14, 15, and 16. Either RF-magnetron or DC-magnetron sputtering can be used with Cu, In, Se, Cu 2 Se, In 2 Se 3 , Cul, CulnSe 2 , CulSe 3 , and Culn 2 Se 3 I targets. A reactive gas such as H 2 Se is introduced as the Se source. Iodine can also be introduced as a reactive vapor or as HI.
CulSe 3 and Culn 2 Se 3 l compounds can be synthesized as polycrystalline bulk materials from stoichiometric melts of Cul and Se, and of Cul and In 2 Se 3 , respectively. The melt technique involves heating the reactant materials in vacuum to above the melting point of the compound and allowing the melt to crystallize during a slow cooling process. Bulk CulSe 3 and Culn 2 Se 3 I materials can serve as targets to sputter deposit thin films or as small area device components.
Many other variations of the above described device are possible such as: (a) Back-wall or front-wall configuration cell; (b) CulnSe 2 homojunction cell; (c) cascade or multijunction cells; or (d) p-CulnSe 2 / Culn x Se y I z /n-type window(e.g. CdS, ITO) cells. The two new semiconductors CulSe 3 and Culn 2 Se 3 I may be used in conjunction with other photovoltaic materials or electronic devices.
The above described configurations and various methods used to deposit the cell components illustrate some of the preferred embodiments, adapted to specific applications. The scope of the invention is to be limited only by the following claims. From the above discussion, many variations will be apparent to one skilled in the art that would yet be encompassed by the spirit and scope of the invention.
REFERENCES CITED
U.S. PATENT DOCUMENTS
U.S. Pat. No. 4,335,266--December, 1980--Mickelson et al
U.S. Pat. No. 4,581,108--April, 1986--Kapur et al
U.S. Pat. No. 4,601,960--July, 1986--Menezes et al
U.S. Pat. No. 4,611,091--September, 1986--Choudary et al
U.S. Pat. No. 4,798,660--January, 1989--Ermer et al
OTHER PUBLICATIONS
Basol B. M. et al, Solar Cells, 27, 299 (1989).
Cahen D. et al, Appl. Phys. Lett., 45, 746 (1984).
Chopra K. L. and Das S. J. `Thin Film Solar Cells`, p. 195-274, Plenum Press (1983).
Hahn H. et al, Z. Anorg. Chem., 303, 107 (1950).
Haneman D., Thin Solid Films, 163, 167 (1990).
Menezes S. et al, Nature, 30, 615 (1983).
Menezes S., Appl. Phys. Lett., 45, 148 (1984).
Menezes S., Solar Cells, 16, 255 (1986).
Moskowitz P. D. et al, SERI/TR-211-3621, (1990).
Noufi R. et al, Solar Cells, 21, 55 (1987).
Thornton J. A. Solar Cells, 21, 41 (1987).
Zweibel K et al, SERI/TR-211-3571, (1989).
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A photovoltaic energy conversion device and methods for forming the same with relatively high efficiency, high stability, low cost, low weight, and low toxicity. The device comprises a thin film n/p or n/i/p type, gradient-doped heterojunction which uses compatible, lattice-matched, non-hazardous semiconducting compounds from the I-III-VI 2 (14), I-III-VI-VII (15) and I-VI 3 -VII (16) series, an ohmic contact (13) to the n-layer comprising a group III metal, a transparent ohmic contact (17) to the p-layer, a grid (18), and an antireflection coating (20).
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CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of application Ser. No. 663,283 filed Sept. 20, 1984 which is a continuation-in-part of application Ser. No. 464,620 filed Feb. 7, 1983, both now abandoned.
FIELD OF THE INVENTION
The present invention relates to an electrically and manually operable door lock. More particularly, this invention concerns a rim lock of the type used on the inside surface of a shop door or the like where individuals are buzzed in and/or out by a shopkeeper or receptionist and where some sort of mechanical actuation of the lock is also possible, at least from outside the door.
BACKGROUND OF THE INVENTION
A remotely actuated door lock can be strike-centered, that is have its actuating mechanism in the strike on the doorjamb or in the lock on the door. Such a strike-centered lock has the disadvantage that it is fairly difficult to retrofit the door with the bulky strike mechanism, and such systems are normally easy to jimmy and otherwise circumvent.
There are many types of door-mounted locks. They may be incorporated in the doorknob assembly, as in U.S. Pat. No. 4,073,527 of Schlage. In another such arrangement as described in U.S. Pat. No. 2,763,888 of Billeter, a pneumatic door-mounted door closer is connected to a pneumatic actuator in a lock mechanism to withdraw the bolt momentarily as the door is just about closed, so that the door bolt does not noisily engage the strike. In U.S. Pat. No. 3,234,766 of O'Brien a small rotary output motor carries a worm on its output shaft that meshes with a gear-sector paul that operates the latch bolt. It is not structured to, or include backset choices, or include the bolt, crosspiece fin, plunger practically one piece assembly, held rigidly together directly in one axis line for greater efficiency and durability. Similarly, U.S. Pat. Nos. 3,576,119 and 3,751,086 of Harris and Geringer, respectively, have a solenoid mounted directly on the door. In U.S. Pat. No. 3,890,608 of Peterson the solenoid is linked to the bolt. A system kinematically identical to that of Peterson is seen in U.S. Pat. No. 4,169,616 also of Peterson which uses a pneumatic actuator.
All such arrangements are fairly bulky, making it impossible to mount them on the inside surface of the thin (narrow) stile of a standard metal-and-glass entrance door of the type used in shops and offices, etc., in such a manner that it can be actuated from outside the door by a standard rim key cylinder. A partial solution to this problem of retrofitting an existing (narrow) thin-stile door is proposed in U.S. Pat. No. 4,099,752 of Geringer. The mechanism of this arrangement is extremely complex, however.
With all these arrangements manual actuation of the lock is frequently impossible, and it is often also impossible to cut out the lock by holding it in a position with its bolt fully retracted. What is more, such locks are normally only set up for one particular type of installation, for instance, an in-swinging door; they cannot be adapted at the site to different setups. the Savarieau et al. and Bright references basically are to latch or fasten the door in a locked position rather than for an alternate to keep a door unlocked, and do not employ the bolt, crosspiece fin, plunger assembly structure. Curtiss et al. and Flodell's strikes do not use one part of the assembly for outswing doors and another means of the assembly for inswing doors, etc., and Rifkin, Hamilton, Cleff, Rau, Spinello, Ewing; Pond and Nikolaus have their relative differences too.
Note, O'Brien's 82 is a threaded member which engages mounting plate 28 and rear housing plate 16 the latter being locked in place by a key 84. It appears that 86 is a shaft on the other side connected to handle 90 and cam 88 and to reiterate O'Brien's invention is mainly a motor driven unit with added solenoid and with mechanical apparatus workings of a different character and different objective than of this present invention of backset choices and bolt, crosspiece fin, and plunger assembly structures, etc.
The other principal disadvantage of such locks is that they must be made in many different models to accommodate different features, depending on security requirements.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an improved manually and electrically operable door rim lock.
Another object of this invention is the provision of such a manually and electrically operable door lock which overcomes the above-given disadvantages, that is, which is of small and simple construction, which can be adapted easily for different installations, and which can be held open manually if desired.
Another object of this invention which is to be mounted in conjunction with an outside standard key cylinder, is to be most easily fixedly mounted on the inside surface of a house, office, store or shopdoor, this door to contain such an outside key cylinder where the door may swing inward or outward when opened. These doors obviously are found to be differently manufactured, some made with less glass and more mounting on the door where door meets frame. Some with more glass and less stile space or mounting area in which to center the standard outside cylinder and for where the mechanical lock mechanism will be joined together with narrow stile doors. This problem can be more intensified in cases of a buck door frame when the door is outswinging and also by different gaps between door and frame.
The object of this invention, while also being electrically actuated and also otherwise mechanically actuated rim, is to face the above problems with this invention being structured to include with, and to accept also as part of itself, interchangeable backset plates or a backset plate with adjustable means. Giving a choice of various backset distance measurement for where the backset of this one lock can be set to, to match up easily with, where a standard mechanical rim key cylinder which may have already been drilled for and installed previously, or may need to be installed in the door to be used in conjunction with this lock invention.
It is also the object of this invention to provide within its already working essential parts. For instance, a shopkeeper may only wish to use the remote feature at certain times of the day, such as after dark, when greater care must be taken, the entrance being left open during the day. Similarly the situation might require an arrangement where people must be buzzed out as well as in, as opposed to a setup where the person leaving can open the lock himself on leaving. In addition it is occasionally necessary to combine the various systems, for example to be able to open the lock manually from the inside at certain times and not at others. The prior-art systems normally do not leave this type of leeway in application, offering only one style of operation per lock.
A rim lock according to this invention has a housing secured to the door stile face usually opposite the hinges of a hinged door and forming a guide extending along a longitudinal axis, a bolt displaceable in the guide along the axis between an inner position generally retracted in the housing and an outer position projecting axially therefrom, a strike on the frame post formed with a recess opening axially toward the door stile and receiving the bolt in the outer position thereof when the stile engages the frame post, and a solenoid mounted in the partition housing and having a coil centered on the axis and a plunger axially reciprocal in the coil and fixed on the bolt sandwiching a crosspiece fin. A spring is operatively braced between the bolt crosspiece fin and housing part and urges the bolt axially outward into the outer position. The solenoid coil can be electrically energized to pull the plunger and bolt, crosspiece fin assembly axially backward against the spring force into the inner position of the bolt. A hold-in latch is operatively engageable between the bolt and the housing for mechanically retaining the bolt in the inner position. A key-operated lock cylinder on the door stile face is coupled to the bolt fin plunger assembly for displacing same axially on key operation of the door cylinder. A manual operating element mounted and pivotal on the housing can be coupled to the bolt assembly for displacing bolt axially on manual pivoting of the element.
Thus with the system of this invention manual actuation from inside and outside in many ways is more easily possible, allowing the door to be opened in the morning from outside or opened from inside by someone leaving through the door. At the same time an in-line solenoid can be energized to retract the bolt both to permit someone to leave as well as to permit them to enter, if desired. In addition the bolt can be held in the retracted position if desired.
According to another feature of this invention is a radially opened recess on the bolt and a hold-open element axially nondisplaceable in the housing and engageable radially in the radial recess. This hold-open element can be a screw or a spring clip. This makes locking out of the remote actuator relatively simple. In one arrangement, the housing is provided with a tubular guide abutment axially aligned with the plunger but on the axially opposite side of the solenoid as the bolt. The plunger and bolt have an axially inwardly projecting extension formed with the radial recess and the latch element is carried on the guide abutment.
It is also within the scope of this invention to provide an inside cylinder mounted on the housing and connected to the element to rotate same. This cylinder can be used only to open the door from the inside, or can be set up to constitute the hold-open position, (unlocked).
According to a further feature of the invention, the housing has an intermediate partition, the bolt carries an abutment axially spaced therefrom, and the spring is a compression spring axially braced between the partition solenoid housing and the fin crosspiece abutment. Such construction is extremely compact and durable.
The knob element of the instant invention can also include a member engageable between the element and the housing for arresting same on the housing in one position permitting axial motion of the bolt assembly but not permitting pivoting of the element and in another position holding the bolt in the inner position and also not permitting pivoting of the element. This member can be a spring pin or a screw threaded in the element, in which case the housing is formed with at least two separate holes in which the screw is engageable in the respective positions. Thus a simple tool can be used to change the style of operation of the lock, something that can be done very easily.
In accordance with another feature of this invention, the multi-strike assembly includes a main block for an outswing door which can in itself be secured to the frame post and formed with a hole constituting the recess and with an angled ramp adjacent the hole. The bolt is engageable with the ramp on closing of the door so that on such closing the ramp cams the bolt into the inner position from which the bolt snaps out again into the recess of the strike when aligned therewith in the fully closed or locked position of the door.
The multi-strike assembly of this invention includes a L and or flat bracket adapted to be secured to the frame post with the main block and the backing block, and screws for securing the bracket to the main block, the bracket to the door frame post, and the main block to the backing block, for inswing dooor installations. This way it is possible to make such a multi-part strike adaptable to any style of installation, on a wood or metal door that swings in or out.
DESCRIPTION OF THE DRAWINGS
The above and other features and advantages will become more readily apparent from the following, it being understood that any feature described with reference to only one embodiment of the invention can be used where possible with any other embodiment. In the accompanying drawing:
FIG. 1 is an exploded perspective front view of a lock according to this invention;
FIG. 2 is a partly schematic exploded perspective rear view of the lock with its multi-feature thumb knob and strike assembly;
FIG. 3 is a partly broken-away perspective view of the assembled lock and an exploded view of its adjustable backset plate in accordance with this invention;
FIG. 4 is a small-scale horizontal section through the lock of the present invention but of the double-cylinder type;
FIG. 5 is a small-scale horizontal section through the lock of FIGS. 1 through 3;
FIG. 6 is a partly broken-away front view vertical section showing a variation on the lock in accordance with this invention;
FIG. 7 is a partly broken-away view of the lock as of FIG. 6;
FIG. 8 is a vertical axial section through as variation of lock according to the invention;
FIG. 9 is a section taken along line XI of FIG. 8; and
FIGS. 10 to 11C show different applications of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As seen in FIGS. 1 to 9, the lock 100 according to the present invention has a parallelepiped metallic housing 20. The housing 20 includes casings 15 and 16 which are made of a durable material. An outer part 16a of the casing 16 contains door mounting holes 32 and a finger level 4. The finger level 4 is rigidly connected to a shaft 5. The shaft 5 is supported by and rotatably bears within a hole 33 in the casing 16. The shaft 5 is fixedly secured to a center 6a of a rotating inner lever 6, by a set screw 6'. The inner level 6 employs two pins 34 which are spaced apart and rigidly perpendicularly connected to a face 6b of the inner rotating lever 6. The two pins 34 are disposed a small and equal distance from an inner circumference 6c of the inner lever 6. The two pins 34 accommodate each of both directions that the finger lever 4 may be turned. In order to actuate a bolt 8 the pins 34 of the inner lever 6 bear against a surface 9a of a crosspiece fin 9 which is fixedly secured to the bolt 8. The crosspiece fin 9, through a hole 36, is clamped between the bolt 8 and a plunger 11 by means of male threads 35 of the bolt 8 and a female threaded hole 37 of the plunger 11. The lock 100 is mechanically engaged in a similar fashion from the rear of the lock 100, as shown in FIGS. 4 and 5, where a rear rotating lever 21 is actuated by a bushing 3 which can accommodate a standard type key cylinder (not shown). The bushing 3 bears in a hole 39 in an interchangeable backset plate 13. The housing 20 is formed from a thick bolt guide end plate 1, an internal partition 2 which is parallel to the bolt guide end plate 1, the interchangeable or an adjustable backset plate 13 and 13a, respectively, which is perpendicular to the bolt guide end plate 1 and seated in a groove 46 of the bolt guide end plate 1, an opposite end reinforcement buffer plate 14, and the two U-section casings 15 and 16. The two casings 15 and 16 are secured together by screws 47 threaded into the edges of the bolt guide end plate 1 and flanges 2a of the partition 2. The housing 20 is secured, as shown in FIGS. 10 and 11a, b, and c, to a rear face 31a of a stile 31, that is the vertical side member of a door, by screws 31b passing through the holes 32 in vertical flanges 22 of the casing 16. If the housing 20 is to extend past the stile 31 of a glazed door, a decorative cover plate can be provided to cover the visible outside face of the plate 13.
The lock 100 is basically centered on an axis A that extends horizontally about 1/2" behind the rear face 31a of the stile 31 it is to be mounted on. The bolt guide end plate 1 is formed centered on the axis A with a cylindrical bore 40 while the partition 2 has a slightly larger bore 41. The bolt 8 made of a strong durable material and the solenoid ore plunger 11 are of a cylindrical shape and extend along the axis A through the bores 40 and 41. The bolt 8 is snugly guided by the bore 40. The bolt 8 has the small-diameter male threaded extension 35 projecting axially inward, that is, to the right in FIG. 1, through the small-diameter hole 36 in the rigid abutment crosspiece fin 9, and is threaded into the female threaded hole 37 at an axially outer end face 11a of the plunger 11.
A solenoid 17 having a dielectric core tube 17a of non-magnetic material such as extruded brass or equivalent in durability is centered on the axis A and has a front end 17d which is received snugly in the hole 41. Also, the solenoid 17 has a front and rear end washers 17b that are axially engaged between a back face 2b of the internal partition 2 and a front face 14a of the end reinforcement plate 14. A rear end 17c of the core tube 17a is engaged over a magnetic attractor abutment 7 of stepped outer diameter. The rear end 17c of the core tube 17a is fitted in an axially centered bore 42 of the end reinforcement buffer plate 14 and an identical hole 43 in the casing 15. The crosspiece fin 9 is therefore fixed between the bolt 8 and plunger 11, which themselves are locked together. A helical compression spring 10 surrounding the plunger 11 is braced axially between a back face 9b of the crosspiece fin 9 and a front face 2c of the partition 2, urging the bolt 8 into the outer position as shown in FIGS. 5 and 9.
This single or two step double, pull and hold solenoid coil 17 is connected via a full-wave bridge rectifier 18 and a capacitor 19 to a series-connected power supply (not shown) formed by a bell-type stepdown transformer (not shown) connected to line, and a switch (not shown), typically a pushbutton switch behind the counter or receptionist's desk of the location employing the lock according to this invention. All wiring except for the transformer can be low voltage so as to be easy to install and very safe. When the switch is closed, the solenoid 17 pulls in the plunger 11, thereby retracting the bolt 8 and the crosspiece fin 9 against the force of the spring 10 so that it moves from the extended or out position shown in FIGS. 5 and 6 to the retracted position shown in FIGS. 4 and 7.
In addition to this electrical actuation of the bolt 8 it is also possible to actuate it manually. From outside the door, having the stile 31 as shown in FIGS. 10 and 11, this is done by having a standard stile-mounted rim lock door cylinder 30 positioned in the same manner as the cylinder for the standard stile-mount flop-type lever lock provided on glazed doors. The cylinder 30 is mounted in place by a standard backing plate that engages the rear face of the stile 31 and screws 26 which extend therefrom into the body of the cylinder 30, to either side of a rearwardly projecting actuating tongue or stem 36'. As is standard, the barrel of the cylinder 30 can be rotated by the appropriately bitted key about the horizontal axis A', which perpendicularly intersects the axis A, to identically rotate the flat stem 36'.
A front face 13' of the interchangeable backset plate 13 of the lock housing 20 is formed centered on the axis A' with the circular hole 39 which may be placed in one of many places on the interchangeable backset plate 13 along a line parallel to the axis line A depending on the relative circumstances of how lock 100 must be mounted on the stile 31 to join with the cylinder 30 mounted on the stile 31. Note is to be taken of the axis line A' and the placement of the lock housing 20 on the stile 31 in FIGS. 10, 11, 11a to 11c, 10a to 10c. Note is also to be taken of the distances on line parallel to axis line A from the bushing 3 on axis line A to the bolt end plate 1 in FIGS. 4, 5, 6 and 8. FIG. 5 shows a larger distance between the bushing 3 and the bolt-end plate 1 than the distance between the bushing 3 and the bolt-end plate 1 shown in FIG. 4. In FIG. 6 the distance is somewhere in between and FIG. 8 shows a distance still greater than that of FIG. 5. The hole 39 in which is journaled a cylindrical rear end 3a of the T-shaped coupling bushing 3 has a cross-slotted front end 3b. The stem 36' engages in one of slots 3c of the bushing 3, depending whether the cylinder 30 is of the vertical-or horizontal-stem type, and is therefore rotationally linked thereto. The bushing 3 in turn is fitted on the other side of the interchangeable backset plate 13 into the rear rotating lever 21 which has an eccentric actuating pin 34' extending parallel to but offset from the Axis A'. The pin 34' lies axially between the crosspiece fin 9 and the bolt-end plate 1 so that, when the bushing 3 and the rear rotating lever 21 rotate, the pin 34' will be able to engage and push back the bolt 8 by engagement with the crosspiece fin 9. A 90° rotation of the key is sufficient to withdraw the bolt 8 completely.
A similar function is accomplished with the adjustable backset plate 13a shown in FIGS. 1 and 3. The adjustable backset plate 13a is composed of a bushing 3a' , which is similar to the bushing 3, and a rectangular backset slide plate 13c which contains a cylindrical bearing hole 39c to receive the bushing 3a' on one side along the center line of the longer length. A small distance from the axis A' in the backset slide plate 13c runs a thin slot 13g. The slot 13g extends almost to the end of the backset slide plate 13c. On the center line of the backset plate 13a running lengthwise to almost one end is a rectangular opening 13d which is slightly smaller than the rectangular slide plate 13c. At the sides of the opening 13d and running parallel to the center line, are 2 tracks 13e which mate with tracks 13h of a square slide 13b for controlling the sliding action thereon. A threaded hole 13f disposed in the adjustable backset plate 13a and parallel with the center line A controls the movement of the rectangular slide 13c along the center line A when joined with a screw 60. The screw 60 is tightened so that it may securely fasten the rectangular slide 13c in the desired position. Similar to the bushing 3, the bushing 3a' engages the stem 36' which is centered on the axis A'. The bushing 3a' in turn enters through the bearing hole 39c of the slide plate 13c, and is journaled there at a T end 3b'. Another end 3c' extends through the rectangular opening 13d of the adjustable backset plate 13a and enters through a bearing hole 39b of the square slide 13b. The bushing 3a' in turn is fitted on the other side of the plates 13c, 13a and 13b into an actuation element cam 21a which has an eccentric actuating pin 34'a extending parallel to but offset from the axis A'. The assembled adjustable backset plate 13a is screwed into the lock 100 using two of the four appropriate symmetrically placed mounting holes 13c with the screws 47 in relative position as shown in FIG. 1. When the slide plate 13c reverses and the bushing 3 is set closer to the bolt 8 and the crosspiece fin 9 end of the lock 100, for the smaller lock backset settings, the pin 34'a similarly as with the pin 34' will be positioned. The slide plate 13c and the bushing 3a are to be set further back and away from the bolt 8 and the crosspiece fin 9 end of the lock 100 for larger backset settings. The backset plate assembly 13a is turned 180° and set in with the screws 47 in a facing position as shown in FIG. 3 for the still larger backset settings. The pin 34'a which runs parallel with the axis A' contains a groove 61 at its outer end 61' to retain a retaining ring 62. Depending upon the desired backset choice, the pin 34'a is passed through one of a selection of holes 63 of a bridge span 64 and the retainer ring 62 is attached to the groove 61 of the pin 34'a. The bridge span 64 is made of a strip of strong sturdy material or metal. The bridge span 64 runs in a direction parallel to the axis line A. Another end 64' of the span 64 which comes close to the crosspiece fin 9 has a fixedly attached pin 34'b running parallel with the axis A' and enjoins with a hole 65 of a snap-on crosspiece 66 which is securely attached to the crosspiece fin 9. The crosspiece 66 is disposed parallel with the crosspiece fin 9 so that with a 90° rotation of the key in the cylinder 30 the action hereto relaid to the crosspiece fin 9 and the bolt 8 is sufficient to withdraw the bolt 8 completely. A choice of backsets for use with this one lock invention can range in distance almost equal to the entire length (parallel to axis A) of this entire lock, however long the lock may be made to be.
From the inside of a room the lock 100 can be opened by means of the finger knob lever 4 with the shaft 5 centered on the axis A' and extending through the hole 33 in the back casing 16 into the inner lever 6 secured in place thereon by the set screw 6'. The rotating inner lever 6 is similar to the rear rotating lever 21 but has the two pins 34 offset angularly relative to each other about the axis A' by about 90°. The two pins 34 are engageable with the axially outer face of the crosspiece fin 9, like the pin 34'. Since there are two pins, 90° rotation of the knob 4 in either direction will retract the bolt 8.
It is also possible as shown in FIG. 4 to replace the lever 4 and the shaft 5 with a mini-cylinder 45 which is carried on a mount 4a on the rear casing 16 and has a stem 3'a, projecting through the casing 16 into the otherwise identical inner lever 6. This gives a double-cylinder operation that can only be opened manually from inside by a person having the key for the cylinder 45, an installation particularly useful around glass. If the key can be made to be withdrawn from the cylinder 45 in 90° positions, this arrangement can also be used to lock the bolt 8 in the inner position.
The lock 100 of the instant invention can also be retained in the open or unlocked condition. This can be done as shown in FIG. 4 by providing a non-magnetic axial extension 44 on an inner end 11b of the plunger 11. The inner end 11b has a frustoconical surface 11c complementary to a seat 7a in the abutment 7, which also acts as a guide for the extension 44. The free end 44a of the extension 44 is formed with a radially outwardly open groove 44b that is aligned in the open lock position with a threaded bore 27 in a free end 7' of the magnetic attractor abutment 7. A thumb screw 38a threaded into the hole 27 can therefore effectively hold the bolt 8 back against the force of the spring 10. Alternately as shown in FIG. 4 a spring clip 38b engaged in grooves 53 of the magnetic attractor abutment 7 can engage into a groove 67 and also lock the bolt 8 in the unlocked position.
Similarly as best seen in FIG. 5 the bolt guide end plate 1 is formed with a bore 49 extending radially from the hole 40 relative to the axis A and has a threaded outer end 49a. The bolt 8 has a radially opened blind hole 48 alignable therewith. A thumb screw 38 can be screwed into the bore 49 to engage in the blind hole 48 and lock the bolt 8 in place.
The strikes according to this invention are shown in FIGS. 2, 10, 10A, B and C and 11, 11 A, B and C. The simplest possible strike 12 which is also 23 is a single plate, normally of a durable material made with a central cylidrical bore 12b slightly larger than the bolt 8 and with a ramp 12c extending from it. The strike 12 and 23 can be secured directly by two screws 13i to an inner face 29' of a standard door post 29 of the outswinging type shown in FIGS. 11, in which case a lip 28 forms the stop which has a portion 28a that is cut away for the strike 12 and 33.
A thicker strike 12a as shown in FIG. 10A is otherwise similar to the strike 12 and can be screwed to the inner face 29' of the door frame 29 for use with an inswinging door.
Virtually any installation can be accommodated by the kit shown in brackets to the right in FIG. 2 and basically comprises a strike plate 23 and 12 identical to the strike plate 12 and 23, another plate 23a, and two brackets 24 and 24a. The plate 23a is secured by two wood or self-tapping screws 54 through either of the brackets 24 or 24a to the door frame 29, and it has a central blind hole 23b. The plate 23 and 12 is secured by two machine screws 56 extending parallel to the axis A to the plate 23a and via two further machine screws 57 to one of the brackets 24 or 24b, which in turn can be secured by screws 58 to the door frame. These parts can be assembled to form a strike 25 for an outswinging wood door or a strike 25a for an outswinging metal door, as shown in FIG. 2. Thus an inexpensive kit of simple parts allows the lock 100 to be adapted to many different installations both inswing and outswing.
FIGS. 2, 6, and 7 show the lock 100 in which the plunger 11 need not be provided with an extension 44. Instead an inside knob 4b is provided with a screw 50 offset from the axis A'. The back casing 16 is formed with a center hole 51 and two side holes 52 around the hole 33. The screw 50 can be screwed down into the hole 51 to lock the knob 4b against rotation, thereby making it necessary to use solenoid action to open the door from the inside. The screw 50 can be screwed down into either of the holes 52 also to hold the bolt 8 in the withdrawn position. A screwdriver 55, allen wrench 55a, or the like can be used to move the screw 50 in or out. Thus it is possible to change the style of operation of the lock 100 in a very simple manner, using simple tools.
A recessed backset plate may be used, as well as a slightly different coupling bushing. Either way the functioning of this arrangement is identical to that of the embodiments described above.
FIGS. 11A and 11B show a lock bolt 8' having a beveled face 8a'. This structure allows the bolt 8' to be pushed back into the housing as the door closes.
In the lock of FIGS. 8 and 9, the bolt 8 actually forms the core of a solenoid 17' and has a long extension 44' that carries the crosspiece fin 9' on which the inside knob 4 and outside key cylinder can act. This structure offers certain advantages in extremely tight mounting locations. In particular this arrangement allows the same coil to be used regardless of the overall lock size. In addition only the core of the bolt 8 is magnetic and the outside is aluminum, so that in an aluminum housing there is no sliding of steel or aluminum with the concomitant wear. The ferrous core of the bolt 8 can also be sheathed in brass, nylon or any other well-wearing non-magnetic material.
In this arrangement, also, the housing 20 is effectively divided into a solenoid part and a manual-actuation part, so that the same solenoid arrangement can be used with different backsets. A relatively deep backset can also be accommodated by this arrangement relatively easily.
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A rim lock which includes a housing, a bolt displaceable in the housing, a strike which receives the bolt, a solenoid which is mounted on the housing and has a coil, a plunger which is axially reciprocal in the coil, a crosspiece fin which is disposed between and which is rigidly affixed to the plunger and the bolt, a front inner lever which has at least one pin and is rotationally mounted in the housing and is in mechanical communication with the crosspiece fin, a spring which is operatively braced between the crosspiece fin and the housing, apparatus which electrically energizes the coil, holding appartus which are operatively engageable between the bolt and the housing and mechanically retains the bolt, a key operated lock cylinder, a rear inner lever which has at least one pin and is rotationally mounted in the housing and is in mechanical communication with the crosspiece fin, and coupling apparatus which includes an interchangeable backset plate which is engaged between the key-operated lock cylinder and the bolt and which displaces the bolt axially upon operation of the key-operated lock cylinder. The interchangeable backset plate is one of a plurality of interchangeable backset plates each being removably mounted to the housing and each having a different backset so that a single rim lock can fit on doors with different size stiles and required backsets.
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This application is a continuation-in-part application of application Ser. No. 08/509,425, filed Jul. 31. 1995, now U.S. Pat. No. 5,925,593.
FIELD OF THE INVENTION
The present invention relates to an improved hot stamping foil, more particularly to a hot stamping foil having a layer which includes a thermochromic compound and an antimicrobial compound.
BACKGROUND OF THE INVENTION
Various systems for transferring ink images onto a substrate, such as a fabric or an article of manufacture, are known. For example, images can be transferred from a heat transfer sheet by the use of heat and pressure. Such sheets (also known as hot-stamp foils) are shown, for example, in U.S. Pat. No. 5,124,309, to Egashira, and U.S. Pat. No. 5,223,476, to Kanto et al.
More complex systems for transferring images are shown, for example, in U.S. Pat. No. 5,244,524, to Yamane. Yamane describes an ink image forming step in which an ink image is formed on a hot melting type adhesive layer of a transfer sheet, followed by an image retransferring step in which the ink image and the hot melting type adhesive layer are transferred onto the substrate by application of heat and pressure.
Various inks and dyes have been employed in known heat transfer sheets or hot-stamp foils. For certain applications, it would be desirable to employ a so-called thermochromic compound, that is, a compound which changes color (typically from colored to colorless or vice versa) at a specified transition temperature. Images so formed can, for example, provide an indication of the temperature of the substrate to which they are applied, or can provide a decorative effect.
Once an image is transferred to a medium, it becomes susceptible to attack by microbes. These microbes feed on the image and the surrounding medium; if present in sufficient numbers, they degrade the appearance of the image and can degrade even the medium itself. One can address this problem by transferring an image to a fabric coated with an antimicrobial agent, as is taught by Rubin et al in U.S. Pat. No. 5,565,265. The fabric thus coated is said to be effective in retarding the growth of microbes.
In a similar manner, one can incorporate an antimicrobial compound directly into plastic products to retard the growth of microbes. The typical method mixes a preservative with the plastic before the plastic is molded or rolled into a sheet. This method has its drawbacks, however. Certain plastics, such as polystyrene, may inhibit the effectiveness of the antimicrobial compound. This method is moreover wasteful: in all molded plastic items, a large proportion of the antimicrobial compound used is unavailable because it is sealed within the plastic. This large proportion is not exposed to the surface, where microbes attack.
It would be desirable to provide an improved hot-stamp foil comprising a layer which includes a thermochromic compound, and preferably a thermochromic layer which provides a reversible thermochromic effect. It would be further desirable to impart microbial resistance to an image transferred by the improved hot-stamp foil.
SUMMARY OF THE PREFERRED EMBODIMENTS
In accordance with one aspect of the present invention, there has been provided a hot stamping foil comprising a carrier, and disposed thereon, a thermochromic layer comprising a mixture of a thermochromic compound, a sizing or adhesive compound, a release compound, and a antimicrobial compound.
In accordance with another aspect of the present invention, a method of producing a hot stamping foil is provided which comprises the steps of: preparing a thermochromic mixture comprising a thermochromic compound, a sizing or adhesive compound, a release compound, and an antimicrobial compound; and applying to a carrier layer a layer of the thermochromic mixture.
According to a further aspect of the present invention, an article of manufacture is provided comprising a substrate and, applied thereto, a hot stamping foil as described above.
According to yet another aspect of the present invention, a method of labeling an article of manufacture is provided comprising the steps of: contacting the thermochromic layer of the hot stamping foil described above with the article; hot stamping the hot stamping foil to cause the thermochromic layer to adhere to the article; and removing the carrier of the hot stamping foil from the thermochromic layer.
The hot stamping foil of the present invention may be applied to a variety of plastics, even to many plastics which inhibit the effectiveness of the antimicrobial compound, and may also be applied to other items that are not made of plastic such as wood, paper, and leather.
Other objects, features and advantages of the present invention will become apparent to those skilled in the art from the following detailed description. It is to be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are given by way of illustration and not limitation. Many changes and modifications within the scope of the present invention may be made without departing from the spirit thereof, and the invention includes all such modifications.
BRIEF DESCRIPTION OF THE DRAWING
The invention may be more readily understood by referring to the accompanying FIG. 1 which is a cross-sectional view of a hot-stamp foil according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention provides an improved thermochromic hot-stamp foil. The thermochromic layer of the inventive hot-stamp foil includes a thermochromic compound, a sizing or adhesive compound, and a release compound in a single layer. No additional release layer is needed between the thermochromic layer and the carrier layer, thus facilitating the manufacture and use of the inventive foil. Thermochromic compounds are described, for example, by Day, “Thermochromism of Inorganic Compounds,” Chemical Reviews 68, p. 649 (1968); in U.S. Pat. No. 3,816,335, to Evans; U.S. Pat. No. 3,980,581, to Godsey; and in U.S. Pat. Nos. 4,105,583 and 4,121,011, to Glover, the disclosures of which are incorporated in their entireties by reference herein. Thermochromic compounds are readily available commercially, for example, from Matsui Shikiso Chemical Co., Ltd. (Kyoto, Japan) and Matsui and Company, Inc. (New Jersey).
The temperature of the color change, or “transition temperature,” of a thermochromic composition depends on the environment and the rate of heating. The transition temperature of any specific thermochromic composition is readily determined by one of ordinary skill in the art. Typically, a range of temperature is required for complete transition from one color state to another. Thus, exemplary thermochromic compounds begin to change color at about 4° C., with completion at about 5° C.; at about 16° C., with completion at about 26° C.; at about 44° C., with completion at about 58° C.; etc.
Thermochromic compounds are produced in a variety of colors and exhibit a variety of color changes with increasing temperature, for example, vermilion to colorless; pink to colorless; turquoise blue to colorless; orange to yellow; black to sky blue; and black to yellow. Multiple color changes can be produced by use of combinations of thermochromic compounds with different transition temperatures, for example, brown to green to yellow.
The thermochromic layer according to the invention further comprises a sizing or adhesive compound. Useful sizing or adhesive compounds include, for example, polyacrylates, polyalkacrylates, vinyl resins including polyvinyl acetate, cellulose resins, polyacrylamides, ethylene/vinyl acetate copolymers, vinyl alcohol, and other such compounds known to those skilled in the art.
The thermochromic layer also comprises a release compound. The release compound facilitates separation of the thermochromic layer from the carrier layer. Useful release compounds include those known to the art, such as microcrystalline wax, rice wax, oricuri wax, polyglycols, stearic acid esters, metallic salts of fatty acids such as zinc, sodium, and lithium stearate, inorganic powders such as silica, and other compounds well known in the art.
The thermochromic layer according to the invention further comprises an antimicrobial compound. An antimicrobial compound is any compound or combination of compounds that kills a microorganism or prevents its growth, and includes antibiotic, antifungal, antiviral, and antialgal compounds. Antimicrobial compounds are widely known. They are readily available commercially from, for example, Dow Chemical Co., Morton Chemical Co., Troy Chemical Co., and Zeneca Chemical Co.
The thermochromic layer according to the invention preferably is reversibly thermochromic, that is, it reverts to its original color once it returns to the initial temperature range. In an embodiment of the present invention, the thermochromic layer also contains a non-thermochromic pigment.
The thickness of the thermochromic layer is about 0.1 to 0.3 mil. According to an embodiment of the present invention, the thermochromic layer is applied to a carrier film. The carrier film can be from 0.25 mil to 2.0 mil thick. The preferred film is polyester (with trade names Hostaphen or Mylar), but polyethylene terephthalate, cellophane, cellulose acetate propionate, and polyvinylidine fluoride (“Tefzel”) can also be used.
Referring now to the drawing, as shown in FIG. 1, thermochromic foil 10 includes carrier 12 on which is disposed thermochromic layer 14 having an upper surface 16 . In use, upper surface 16 is contacted with an object or surface which is to be labeled. Heat and pressure are applied to the foil 10 . Carrier 12 is then removed, leaving thermochromic layer 14 affixed to the object to which it was applied.
This application process is known as hot stamping. The temperature used in this process ranges from 200° F. to as high a temperature as the carrier can take before melting. The preferred temperature range is 400° F. to 550° F.
The amount of pressure applied in the hot stamping process varies. Preferably around 7 to 9 pounds per square inch are applied for a period of about 0.5 to 2 seconds.
The invention is further illustrated by the following non-limiting examples:
EXAMPLE 1
A coating having the following formulation was prepared and applied to a carrier film:
Ingredient
Amount (wt %)
Styrene acrylic emulsion
27.5
Ammonium zirconium carbonate solution
6.5
Sodium polyacrylate solution
2.25
Polyoxyethylene glycols
0.125
Microcrystalline wax
5.0
Deionized water
4.625
Isopropyl alcohol
4.0
Yellow thermochromic pigment dispersion
50.0
The formulation was prepared by first premixing the sodium polyacrylate solution with the ammonium zirconium carbonate solution. Then the styrene acrylic emulsion was added. Next was added the microcrystalline wax, deionized water, isopropyl alcohol and polyoxyethylene glycols. Lastly, the yellow thermochromic pigment dispersion was added. Mixing was done at a shear to avoid rupturing the encapsulated pigment.
The formulation affords a yellow color at the thermochromic temperature, and a white transparent (clear) residual coloring when the thermochromic pigment coloration disappears.
EXAMPLE 2
In the same manner as Example 1, the following coating formulation was prepared and applied to a carrier film:
Ingredient
Amount (wt %)
Styrene acrylic emulsion
22.55
Ammonium zirconium carbonate solution
5.33
Sodium polyacrylate solution
1.845
Polyoxyethylene glycols
0.103
Microcrystalline wax
4.1
Deionized water
3.792
Isopropyl alcohol
3.28
Blue thermochromic pigment dispersion
58.5
Yellow pigment dispersion
0.5
The formulation affords a green color at the thermochromic temperature, and a yellow residual coloring when the thermochromic pigment coloration disappears.
EXAMPLE 3
The following coating formulation was prepared and applied to a carrier film:
Ingredient
Amount (wt %)
Styrene acrylic emulsion
27.5
Ammonium zirconium carbonate solution
6.5
Sodium polyacrylate solution
2.25
Polyoxyethylene glycols
0.125
Microcrystalline wax
5.0
Deionized water
4.625
Isopropyl alcohol
4.0
Magenta thermochromic pigment dispersion
50.0
The formulation affords a magenta color at the thermochromic temperature, and a white transparent (clear) residual coloring when the thermochromic pigment coloration disappears.
EXAMPLE 4
The following coating formulation was prepared and applied to a carrier film:
Ingredient
Amount (wt %)
Isopropyl alcohol
25.0
Huls resin CA (Ketone formaldehyde resin)
30.0
Microcrystalline wax
5.0
Blue thermochromic pigment dispersion
40.0
The formulation affords a blue color at the thermochromic temperature and a white transparent (clear) residual coloring when the thermochromic pigment coloration disappears.
EXAMPLE 5
The following coating formulation was prepared and applied to a carrier film:
Ingredient
Amount (wt %)
Acryloid NAD-10 (acrylic resin dispersion in
40.0
mineral spirits)
Mineral spirits
6.0
Microcrystalline wax
4.0
Red thermochromic pigment dispersion
40.0
Yellow pigment dispersion
10.0
The formulation affords a red color at the temperature and a yellow residual coloring when the thermochromic pigment coloration disappears.
EXAMPLE 6
A coating having the following formulation was prepared and applied to a carrier film.
Ingredient
Amount (wt %)
Styrene Acrylic Emulsion
61.65
Ammonium zirconium carbonate solution
8.65
Sodium polyacrylate solution
2.44
Microcrystalline Wax
5.00
Deionized water
15.22
Propylene glycol monomethyl ether
4.60
Ammonium hydroxide
0.44
Diisodecylphthalate
1.96
10, 10 oxybisphenoxyarsine
0.04
The coating when transferred to a plastic item provides a barrier containing about 800 parts per million of the antimicrobial compound 10, 10 oxybisphenoxyarsine. (Morton Vinyzene BP-5-2-DIDP) Biological challenge tests run showed that the coating was effective in inhibiting the growth of gram positive and gram negative bacteria and various molds.
EXAMPLE 7
A coating having the following formulation was prepared and applied to a carrier film.
Ingredient
Amount (wt %)
Styrene acrylic emulsion
42.55
Melamine acrylic emulsion
4.00
P-toluene sulfonamide catalyst
0.10
Microcrystalline Wax
7.44
Deionized water
15.60
Isopropyl alcohol
3.50
Ammonium hydroxide
0.56
Pigment Blue 15 dispersion
26.00
Diisodecylphthalate
0.15
Trichlorophenoxyphenol
0.10
The hot stamp foil when transferred to a plastic item provides a blue barrier coating containing about 2000 parts per million of the antimicrobial compound trichlorophenoxyphenol. (Morton Vinyzene DP-7040 DIDP)
EXAMPLE 8
A coating having the following formulation was prepared and applied to a carrier film.
Ingredient
Amount (wt %)
Styrene acrylic emulsion
67.37
Ammonium zirconium carbonate solution
6.5
Sodium polyacrylate solution
2.3
Polyoxyethylene glycols
0.13
Microcrystalline wax
5.0
Deionized water
14.5
Isopropyl alcohol
4.0
3-iodo-2-propynyl butyl carbamate
0.20
The hot stamp foil when transferred to a plastic item provides a barrier coating that contains about 3600 parts per million of the antimicrobial compound 3-iodo-2-propynyl butyl carbamate. (Troysan Polyphase WD-17)
EXAMPLE 9
A coating having the following formula was prepared and applied to a carrier film.
Ingredient
Amount (wt %)
Isopropyl alcohol
34.5
Ketone formaldehyde resin
60.0
Microcrystalline wax
5.0
3-iodo-2-propynyl butyl carbamate
0.5
The hot stamp foil when applied to a wood surface provides a barrier coating that contains about 5000 parts per million of the antimicrobial compound 3-iodo-2-propynyl butyl carbamate.
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A hot stamping foil includes a carrier, and disposed thereon, a thermochromic layer. The thermochromic layer includes a mixture of a thermochromic compound, a sizing or adhesive compound, a release compound, and an antimicrobial compound. The hot stamping foil is useful in creating various visual effects and also preventing the growth of microbes on a medium to which the hot stamping foil is applied.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates generally to a control application for a HVAC&R system. More specifically, the present invention relates to a system and method for humidity control in a HVAC&R system.
[0002] To achieve climate control for a structure or enclosed space, a heating, ventilation, air conditioning and refrigeration (HVAC&R) or air treatment system is commonly used. The HVAC&R system is typically thermostat controlled to provide temperature control for the interior space of the structure. However, in addition to temperature, other parameters are significant for providing comfort to the occupants within the structure. For example, relative humidity, or the ratio of the amount of water vapor actually present in the air to the greatest amount possible at the same temperature, is one such parameter. At increased levels of relative humidity, the temperature must be lowered to provide an equivalent level of comfort for an individual. Complicating matters, individual sensitivity to changes in humidity and temperature differ, so that it is not possible to provide a definitive temperature correction when humidity levels are elevated.
[0003] Several techniques have been used to control humidity within a structure. These techniques typically include a combination of reheating and/or cooling the air. Cooling the air, such as by passing the air through evaporator coils, removes moisture from the air since an amount of the air moisture collects and condenses on the evaporator coils. Heating may then need to be performed to raise the air temperature to a level that is comfortable to the occupant. Having both heating and cooling adds HVAC&R components, complexity and cost.
[0004] What is needed is a control for use with HVAC&R systems that is simple to operate, and which can provide an individualized temperature/humidity correction inside a structure in response to elevated humidity levels.
SUMMARY OF THE INVENTION
[0005] The present invention is directed to a method for controlling humidity in a structure with a HVAC&R system. The method steps include: sensing a temperature and a humidity level inside a structure; calculating a temperature correction value in response to a predetermined humidity level, the sensed humidity level and a predetermined humidity sensitivity factor; comparing a predetermined temperature setting for a HVAC&R device with the sum of the sensed temperature and the temperature correction value; and initiating operation of the HVAC&R device to reduce the humidity level inside the structure when the sum of the sensed temperature and the temperature correction value is greater than the predetermined temperature setting.
[0006] The present invention further includes a controller for controlling humidity in a structure with a HVAC&R system. The controller includes a first sensor for sensing a temperature inside a structure and a second sensor for sensing a humidity level inside the structure. A controller is responsive to the first and second sensors for a HVAC&R device, the controller calculating a temperature correction value in response to a predetermined humidity level, the sensed humidity level and a predetermined humidity sensitivity factor. The controller initiates operation of the HVAC&R device to reduce the humidity level inside the structure when the sum of the sensed temperature and the temperature correction value is greater than the predetermined temperature setting.
[0007] One advantage of the present invention is that it reduces elevated humidity levels within a structure.
[0008] Another advantage of the present invention is that it can provide a selectable relationship between temperature and elevated humidity levels within a structure.
[0009] A further advantage of the present invention is that it requires a minimum amount of memory to operate.
[0010] A yet further advantage of the present invention is that it is extremely simple to operate.
[0011] Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 illustrates schematically an embodiment of a heating, ventilation and air conditioning or refrigeration system for use with the present invention.
[0013] FIG. 2 illustrates a flow chart detailing the humidity control method of the present invention.
[0014] Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
DETAILED DESCRIPTION OF THE INVENTION
[0015] One embodiment of the heating, ventilation and air conditioning or refrigeration (HVAC&R) system 10 of the present invention is depicted in FIG. 1 . Compressor 12 is connected to a motor 14 and inverter or variable speed drive (VSD) 16 , for selectively controlling operational parameters, such as rotational speed, of the compressor 12 . Compressor 12 is typically a positive displacement compressor, such as screw, reciprocating or scroll, having a wide range of cooling capacity, although any type of compressor can also be used. The controller 20 includes logic devices, such as a microprocessor or other electronic components, for controlling the operating parameters of compressor 12 by controlling VSD 16 and motor 14 . AC electrical power received from an electrical power source 18 is rectified from AC to DC, and then inverted from DC back to variable frequency AC by VSD 16 for driving compressor motor 14 . The compressor motor 14 is typically an AC induction motor, but might also be brushless permanent magnet motor or switched reluctance motor.
[0016] Refrigerant gas that is compressed by compressor 12 is directed to the condenser 22 , which enters into a heat exchange relationship with a fluid, preferably water, flowing through a heat-exchanger coil 24 connected to a cooling tower 26 . The refrigerant vapor in the condenser 22 undergoes a phase change to a refrigerant liquid as a result of the heat exchange relationship with the liquid in the heat-exchanger coil 24 . The condensed liquid refrigerant from condenser 22 flows to an expansion device 28 , which lowers the pressure of the refrigerant before entering the evaporator 30 . Alternately, the condenser 22 can reject the heat directly into the atmosphere through the use of air movement across a series of finned surfaces (direct expansion condenser).
[0017] The evaporator 30 can include a heat-exchanger coil 34 having a supply line 34 S and a return line 34 R connected to a cooling load 36 . The heat-exchanger coil 34 can include a plurality of tube bundles within the evaporator 30 . Water or any other suitable secondary refrigerant, e.g., ethylene, calcium chloride brine or sodium chloride brine, travels into the evaporator 30 via return line 34 R and exits the evaporator 30 via supply line 34 S. The liquid refrigerant in the evaporator 30 enters into a heat exchange relationship with the water in the heat-exchanger coil 34 to chill the temperature of the water in the heat-exchanger coil 34 . The refrigerant liquid in the evaporator 30 undergoes a phase change to a refrigerant gas as a result of the heat exchange relationship with the liquid in the heat-exchanger coil 34 . The gas refrigerant in the evaporator 30 then returns to the compressor 12 .
[0018] Controller 20 , which controls the operations of HVAC&R system 10 , employs continuous feedback from indoor temperature sensor 38 and humidity sensor 40 to continuously determine whether to incorporate a temperature correction to achieve a reduction in the humidity level within the structure being cooled by the system 10 . In other words, the humidity reduction control of the present invention is preferably used when the HVAC&R system 10 is in a cooling mode.
[0019] The HVAC&R system 10 is first discussed without considering the humidity sensor 40 . An operator initially inputs a desired temperature setting “T D ”, or settings if multiple temperatures are to be achieved at different times of the day or different days, which are typically referred to as programmed settings. Once the desired temperature setting(s) T D have been input, the sensed temperature inside a structure “T S ” as sensed by the indoor temperature sensor 38 is compared to the desired temperature setting T D which was previously input into the controller 20 by the operator. When the inside temperature T S of the structure as sensed by the indoor temperature sensor 38 is greater than the desired temperature setting T D , the controller 20 activates the HVAC&R system 10 to operate in cooling mode. The HVAC&R system 10 continues to operate in cooling mode until the desired temperature setting is achieved, wherein upon achieving the desired setting, the HVAC&R system 10 is deactivated. This process is then repeated to provide temperature control inside of the structure.
[0020] While providing temperature control of the temperature inside of the structure, other parameters important to the comfort of the occupants of the structure, such as humidity control, are not taken into account in the above-referenced process. The HVAC&R system 10 is again discussed, with the addition of the humidity sensor 40 , which senses a relative humidity percentage inside the structure “H S ”, and a corresponding control algorithm that is programmed into the controller 20 . In addition to initially inputting a desired temperature setting(s) T D , an operator additionally inputs a desired relative humidity percentage “H D ” and a humidity sensitivity factor “H stv ”. A humidity sensitivity factor “H stv ” is a correction factor that correlates an excess in percentage of the relative humidity inside the structure to a reduction of the temperature inside the structure, which reduction in temperature being referred to as a temperature correction “T C ”. More specifically, the temperature correction T C can be calculated by subtracting the desired relative humidity percentage H D from the sensed relative humidity H S , and dividing that result by the humidity sensitivity factor H stv as shown in equation 1.
T C =( H S −H D )/ H stv [1]
[0021] Stated another way, a humidity sensitivity factor of 5, for example, means that for every 5 percent the sensed humidity percentage H S , as sensed by the humidity sensor 40 , exceeds the desired relative humidity percentage H S , the temperature correction T C inside the structure must be lowered by one ° F. to achieve a similar level of comfort due to the humidity. The humidity sensitivity factor H stv is subjective, possibly differing for each individual, and can range from about 1 up to about 10, although typically it is about 5 or less.
[0022] In operational example, assume the following input values: desired relative humidity percentage H D is 50 percent, the humidity sensitivity factor H stv is 5, the desired temperature setting TD is 70° F. and a maximum correction temperature “T CMAX” is 5. The maximum correction temperature T CMAX is an operator-input maximum deviation temperature from the desired temperature T D . Further assume a sensed relative humidity H S of 80 percent and a sensed inside structure temperature T S of 70° F. In a conventional HVAC&R system, since the sensed inside structure temperature T S and the desired temperature setting T D are equal, the HVAC&R system would remain deactivated. However, since the sensed relative humidity H S is greater than the desired relative humidity H D , occupants within the structure can be made more comfortable by cooling the temperature within the structure as provided by the control algorithm. The temperature correction T C as provided by equation [1] is calculated as follows: (80−50)/5, which simplifies to 6° F. However, in this example, the maximum correction temperature T CMAX is 5, or 5° F., so the maximum correction temperature value is applied in place of the calculated correction temperature. By application of the control algorithm in this example, the equivalent temperature inside the structure is reduced by the maximum correction temperature T CMAX , so that the HVAC&R system is activated to operate until the temperature inside the structure is lowered to 65° F., at which point the HVAC&R system is deactivated.
[0023] In summary, for the above example, occupants inside the structure are made more comfortable by operation of the control algorithm, since the elevated level of relative humidity is reduced as the air inside the structure is passed through the evaporator coils for the additional time required to cool the structure by the amount of temperature correction T C . This process is then repeated to provide temperature and humidity control inside of the structure.
[0024] After the control algorithm completes a cycle, especially when the sensed relative humidity H S is significantly greater than the desired relative humidity H D , the reduction of the sensed relative humidity H S is typically sufficient to likewise reduce the amount of temperature correction T C . In the above example, after the temperature inside the structure is lowered to 65° F., if the relative humidity inside the structure is reduced to 70 percent, the temperature correction of equation [1] is calculated as follows: (70−50)/5, which simplifies to 4° F. By application of the algorithm, the equivalent temperature inside the structure is reduced by less than the maximum correction temperature T CMAX , or 4° F. Thus, upon the temperature inside the structure being sufficiently raised to activate the HVAC&R system, the HVAC&R system operates until the temperature inside the structure is lowered to 66° F., at which point the HVAC&R system is deactivated. In other words, so long as the control algorithm removes more moisture from the air inside the structure than is added, such as by activities of the occupants or by moisture producing processes occurring within the structure, the temperature correction should continue to decrease. As the relative humidity inside the structure is reduced to the desired humidity level, the temperature correction approaches zero.
[0025] Although the desired relative humidity level could be set to an extremely low level, such as thirty percent or less, there is typically little benefit, from a comfort standpoint, to reduce the humidity below a level of about 45 percent.
[0026] The controller 20 can include an analog to digital (A/D) converter, a microprocessor, a non-volatile memory, and an interface board to control operation of the HVAC&R system 10 . The controller 20 can also be used to control the operation of the VSD 16 , the motor 14 and the compressor 12 . The controller 20 executes a control algorithm(s) or software to control operation of the system 10 . In one embodiment, the control algorithm(s) can be computer programs or software stored in the non-volatile memory of the controller 20 and can include a series of instructions executable by the microprocessor of the controller 20 . While it is preferred that the control algorithm be embodied in a computer program(s) and executed by the microprocessor, it is to be understood that the control algorithm may be implemented and executed using digital and/or analog hardware by those skilled in the art. If hardware is used to execute the control algorithm, the corresponding configuration of the controller 20 can be changed to incorporate the necessary components and to remove any components that may no longer be required.
[0027] FIG. 2 illustrates a flow chart detailing the control process of the present invention relating to cooling control in an HVAC&R system 10 , as shown in FIG. 1 , wherein control is maintained by the thermostat (not shown). The cooling control process of FIG. 2 can also be implemented as a separate control program executed by a microprocessor, or control panel, or controller 20 or the control process can be implemented as a sub-program in the control program for the HVAC&R system 10 . Once the process is started in step 105 of FIG. 2 , values are selected and set for the desired humidity percentage H D , the humidity sensitivity factor H stv , desired temperature T D and the maximum temperature correction T CMAX in step 110 . Controller keypads on existing controllers 20 or other suitable entry devices can be used with the control algorithm and can be used to enter all required parameters. After the desired humidity percentage H D , humidity sensitivity factor H stv , desired temperature T D and maximum temperature correction T CMAX are set, the temperature inside the structure T S as sensed by the indoor temperature sensor 38 and the relative humidity H S as sensed by the humidity sensor 40 are sensed in step 115 . Once the temperature inside the structure T S and the relative humidity H S are sensed, the sensed relative humidity H S is compared to the desired humidity percentage H D in step 120 .
[0028] In step 120 , if the sensed relative humidity H S is greater than the desired humidity percentage H D , then a calculation is performed to determine the humidity correction temperature T C in step 125 . However, if in step 120 , the sensed relative humidity H S is not greater than the desired humidity percentage H D , a humidity temperature correction is not greater than zero, the humidity temperature correction T C is set to zero in step 140 and control of the process is returned to step 145 .
[0029] Once the humidity temperature correction T C in step 125 has been calculated, the humidity temperature correction T C is compared to the maximum temperature correction T CMAX in step 130 . If the humidity correction temperature T C is greater than the maximum temperature correction T CMAX in step 130 , the humidity temperature correction T C is set equal to the maximum temperature correction T CMAX in step 135 and control of the process is returned to step 145 . However, if the humidity temperature correction T C is not greater than the maximum temperature correction T CMAX in step 130 , the value of the humidity temperature correction T C is retained, and control of the process is returned to step 145 .
[0030] In step 145 , the desired temperature T D is compared to the resulting value obtained by adding the humidity temperature correction T C and the sensed temperature inside the structure T S . If the desired temperature T D is less than the resulting value obtained by adding the humidity correction temperature T C and the sensed temperature inside the structure T S , the HVAC&R system 10 is activated in step 150 and control of the process is returned to step 145 . However, if in step 145 the desired temperature T D is greater than the resulting value obtained by adding the humidity correction temperature T C and the sensed temperature inside the structure T S , a query is performed as to whether the HVAC&R system 10 is activated in step 155 . If the HVAC&R system 10 is activated, the HVAC&R system 10 is deactivated in step 160 and control of the process is returned to step 115 , wherein the process between steps 115 - 160 are repeated. However, if the HVAC&R system 10 is not activated in step 155 , control of the process is returned to step 115 , wherein the process between steps 115 - 160 are repeated.
[0031] In another embodiment, after activating the HVAC&R system 10 in step 150 , the control can return to step 115 and steps 115 - 160 can be repeated.
[0032] In addition to use with commercial HVAC&R systems, including roof-mounted configurations, the control process of the present invention can also be used with residential structures. The residential structures include split systems where the condenser is located outside the structure.
[0033] While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.
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A controller controls operation of a HVAC&R device to reduce an interior humidity level for a structure to provide comfort for occupants of the structure. The controller includes a first sensor for sensing a temperature inside a structure and a second sensor for sensing a humidity level inside the structure. A controller is responsive to the first and second sensors for the HVAC&R device operating in a cooling mode to reduce the humidity level inside the structure. The controller calculates a temperature correction to a predetermined temperature setting for the HVAC&R device, the temperature correction calculation being obtained by subtracting the sensed humidity level from a predetermined humidity level and dividing the result by a predetermined factor. The controller initiates operation of the HVAC&R device when the sum of the sensed temperature and the temperature correction is greater than the predetermined temperature.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a semiconductor device equipped with a heat-fusible thin film resistor, and to a method of producing such a semiconductor device.
2. Description of the Related Art
A semiconductor device including a thin film resistor consisting of a chromium silicon (CrSi) type film and covered with a insulator including silicon film is known as a semiconductor device equipped with a heat-fusible thin film resistor (refer to Japanese Unexamined Patent Publication (Kokai) No. 3-106055). A semiconductor device having a structure including thin film resistor consisting of a chromium silicon (CrSi) type film and a metal oxide layer for lowering a fusing temperature of this thin film resistor, laminated on the thin film resistor, is also known (refer to Japanese Unexamined Patent Publication (Kokai) No. 6-61353).
The semiconductor device described above, wherein the thin film resistor consisting of the chromium silicon (CrSi) type film is covered with the insulator including silicon film, has excellent characteristics as a fuse fusible type semiconductor device including that it exhibits a small volume change at the time of fusing.
In such a fuse fusible type semiconductor device, however, energy required for fusing is great, and thermal losses such as cracks occurring in the insulation film including silicon covering the surface of the semiconductor device, and deterioration of thermal characteristics, are likely to occur. Energy necessary for fusing can be lowered by laminating a metal oxide on the thin film resistor, but the resulting fusing temperature is not sufficiently lowered and further lowering is necessary.
In view of the technical background described above, the present invention is directed to provide a fuse fusible type semiconductor device which requires less energy for fusing than conventional fuse fusible type semiconductor devices, but which does not cause thermal losses and deterioration of thermal characteristics such as cracks in an insulator including silicon covering the surface.
SUMMARY OF THE INVENTION
As a result of intensive studies in search for various fuse materials, the inventors of the present invention have discovered a thin film resistor capable of drastically reducing fusing energy when used as a thin film resistor, and have completed the present invention.
The semiconductor device, according to the present invention, comprises a silicon substrate; a first insulator film formed on said silicon substrate, being made of a insulator including silicon; a thin film resistor formed on said first insulator film, as a fuse, comprising chromium, silicon and tungsten; a wiring portion formed on said thin film resistor, being made of aluminum or an alloy thereof; and a passivation film formed in contact with said wiring portion and said thin film resistor, being made of at least one compound selected from a silicon nitride and a insulator including silicon.
A method of producing a semiconductor device according to the present invention comprises the steps of: a lamination step of sequentially forming, on a semiconductor substrate through a first insulator film, a thin film resistor comprising chromium, silicon, and tungsten as a fuse and a film for wiring made of aluminum or an alloy thereof; an etching step of removing said film for wiring laminated on said thin film resistor by etching; and a passivation step of depositing a passivation film on the surface of the laminate subjected to said etching treatment, said passivation film being made of at least one compound selected from a silicon nitride and an insulator including silicon.
One of the characterizing features of the semiconductor device according to the present invention resides in that the heat-fusible thin film resistor is made of chromium, silicon and tungsten. When tungsten is added to a thin film resistor made of chromium-silicon, an amorphous ternary alloy is formed and its melting point lowers. For this reason, the thin film resistor made of chromium, silicon and tungsten can drastically reduce the thermal energy required to fuse the thin film resistor. As a result, the thermal stress applied to the insulation film including silicon covering the upper surface of the thin film resistor can be reduced, and the occurrence of cracks and the deterioration of thermal characteristics can be prevented.
When the crystal structure of the cross section of the thin film resistor fused by the feed of power is analyzed by a transmission electron microscope, it is observed that an intermetallic compound having a high melting point, i.e. Cr 3 Si, precipitates in the case of the conventional chromium-silicon thin film resistor. In the case of the chromium-silicon-tungsten thin film resistor according to the present invention, on the other hand, an intermetallic compound having a low melting point, i.e. CrSi 2 , precipitates. It is presumed from this fact that when tungsten is added to chromium-silicon to form an amorphous ternary alloy, a crystalline intermetallic compound having a low melting point is formed by heating, and cutoff of the current occurs at a portion of fusion or sublimation of this intermetallic compound. As a result, the total energy required for fusing is believed to drastically drop.
It could be understood from the above description that the thin film resistor of the present invention can reduce the thermal energy required for fusion and can decrease the thermal stress imparted to the insulator including silicon such as the silicon nitride film covering the upper surface of the thin film resistor, thereby preventing deterioration, in comparison with the conventional chromium-silicon thin film resistor.
The chromium-silicon-tungsten thin film resistor contains at least 20 to 50 atm % of chromium, at least 1 to 20 atm %, preferably 2 to 14 atm %, of tungsten, and the balance of silicon.
This chromium-silicon-tungsten film preferably has a composition capable of precipitating an intermetallic compound having a low melting point at the time of heat-fusion, from the aspect of its object. Small quantities of additives such as oxygen, nitrogen, and so forth, may be contained in this chromium-silicon-tungsten film.
Besides the silicon oxide film (SiO x ), PSG (phosphosilicate glass), BSG (borosilicate glass), BPSG (borophosphosilicate glass), etc., can be used as the insulator including silicon film to be formed on the upper surface of the thin film resistor. Further, SiN (silicon nitride) can be employed, too. Though this insulator including silicon film is preferably disposed on both upper and lower surfaces of the thin film resistor in contact therewith, it may be disposed on at least one of the surfaces.
The semiconductor device according to the present invention can be produced by sequentially forming the thin film resistor, the barrier film made of a tungsten alloy, and the aluminum film for wiring on the substrate through a first insulating film, then removing the barrier film and the aluminum film on the fusing region of the thin film resistor by etching, and forming the insulator including silicon film on the surface of the laminate subjected to the etching treatment.
The barrier film made of the tungsten alloy and disposed on both sides of the fusing opening portion of the upper surface of the thin film resistor preferably uses an alloy containing at least 5 to 50 atm % of tungsten and the balance of a metal. Small amounts of other additives may be contained in the barrier film.
In the semiconductor device according to the present invention, the chromium-silicon-tungsten film constituting the thin film resistor can be heat-fused at a lower level of energy. Though this fusing mechanism has not yet been clarified, the intermetallic compound having a low melting point, i.e. CrSi 2 , is found formed from the observation of the section of the thin film resistor after heat-fusion. On the other hand, an intermetallic compound having a high melting point, i.e. Cr 3 Si, precipitates as revealed through the observation of the cross section of the chromium-silicon thin film resistor according to the prior art. It is presumed that the existence of tungsten promotes the formation of an amorphous alloy in the thin film resistor which turns into the intermetallic compound of the low melting product by heating, so that the fusing can be performed at a lower level of fusing energy. As a result, fusing energy required for fusing the fuse can be drastically reduced in comparison with the chromium-silicon thin film resistor according to the prior art. Since the required fusing energy is small, the semiconductor device according to the present invention has small thermal defects such as cracks of the protective film, has high reliability and long durability, and is easy to handle because the range of the fusing voltage is broad.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view showing an embodiment of the apparatus of the present invention;
FIG. 2 is a sectional view showing a production process of FIG. 1;
FIG. 3 is a sectional view showing a production process of FIG. 1;
FIG. 4 is a characteristic diagram showing the relation between energy necessary for fusing and an impressed voltage of the embodiment of the present invention and a comparative example; and
FIG. 5 is a sectional view showing an apparatus of Comparative Example 2.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a sectional view of a semiconductor device equipped with a heat-fusible thin film resistor to which the present invention is applied.
This semiconductor device comprises a silicon substrate 1, a silicon oxide film 2 formed on this silicon substrate 1, a fuse 3 of a thin film resistor consisting of a chromium-silicon-tungsten film formed on the silicon oxide film 2, a barrier metal portion 4 and an aluminum wiring portion 5 formed in lamination on both sides of a fusing region 31 of this fuse 3, a PSG film 7 formed on these barrier metal portion 4, aluminum wiring portion 5 and fusing region 31 of the fuse 3, and a silicon nitride film (SiN) 8 for passivation, formed on this PSG film 7.
The semiconductor device equipped with this thin film resistor was produced through the following production steps.
First, a 1.2 μm-thick silicon oxide film 2 was formed as a base insulating film on the silicon substrate 1 by an oxidization process. The silicon dioxide film 2 may be formed by a CVD process in place of the oxidization method. Next, a 0.015 μm-thick chromium-silicon-tungsten film was formed on this silicon dioxide film 2 by a PVD process and was then etched into a predetermined shape so as to obtain the fuse 3 (heat-fusible thin film resistor).
A composite insulating film consisting of a silicon nitride layer as a lower layer and a silicon oxide film as an upper layer may be used as the base insulating film, and boron or phosphorus may be doped into the silicon oxide film. The chromium-silicon-tungsten film has a composition consisting of 29 atm % of Cr, 65 atm % of Si and 6 atm % of W.
Next, a 0.15 μm-thick titanium tungsten (TiW) alloy film 40 was formed by the PVD process, and a 1.1 μm-thick aluminum film 50 was formed on the TiW alloy film 40 by the PVD process. FIG. 2 shows the cross section of the resulting laminate. By the way, the titanium tungsten alloy film 40 has a composition consisting of 90 atm % of Ti and 10 atm % of W.
A photoresist was disposed on the aluminum film 50, and only the titanium tungsten alloy film 40 and the aluminum film 50 were wet etched by using a mask obtained by opening the resist by photolithography.
In this way, the aluminum wiring portions 5 were formed on both end portions of the fuse 3 in such a manner as to interpose the barrier metal portion 4 made of titanium tungsten between them (see FIG. 3).
Next, as shown in FIG. 1, a 0.4 μm-thick PSG film 7 was formed by the CVD process and a 0.5 μm-thick silicon nitride (SiN) film 8 was formed by a plasma CVD process. Pad portions (not shown) were then formed by selective opening of these films 7 and 8, and wire bonding was carried out to the pad portions. The semiconductor device of this embodiment was produced through a series of these process steps.
COMPARATIVE EXAMPLE 1
A semiconductor device of Comparative Example 1 having the same structure as that of the semiconductor device of this embodiment was produced in the same way as described above with the exception that a chromium silicon film was used for the fuse 3 of the thin film resistor in place of the chromium-silicon-tungsten film.
Evaluation
Energy necessary for fusing was measured for the semiconductor device of this embodiment and the semiconductor device of Comparative Example 1, and fusing performances of both the fuses 3 were comparatively examined. FIG. 4 shows the result of this measurement test. The fusing region 31 of each of these semiconductor devices had a thickness of 0.015 μm, a length of 9.6 μm and a width of 6.4 μm.
The ordinate in FIG. 4 represents input energy per unit area of the fusing region expressed by input power (fusing voltage×feed current×pulse feed time×number of pulses) which was measured by a power meter in the test. The pulse feed time was kept constant (here, 1 microsecond). The abscissa represents a fusing voltage.
It can be seen from FIG. 4 that input energy drops when the fusing voltage is increased, but at a low fusing voltage, the energy necessary for fusing is extremely smaller in the product of this embodiment than in the product of Comparative Example 1. Accordingly, the product of this embodiment can by far greatly reduce the energy necessary for fusing than the product of Comparative Example 1.
The section of the fusing region 31 of each of these two semiconductor devices was observed by a transmission electron microscope so as to analyze the crystal structure. As a result, precipitation of an intermetallic compound, i.e. CrSi 2 , having a low melting point was observed in the fuse 3 of the semiconductor device of this embodiment. On the other hand, precipitation of an intermetallic compound, i.e. Cr 3 Si, having a high melting point was observed in the fuse 3 of the semiconductor device of Comparative Example 1.
In consideration of the observation result of the cross section by the transmission electron microscope, etc., it is estimated that such lowering of the melting point of the fuse 3 results from the following fact. Namely, the intermetallic compound precipitated upon heating due to the feed of power to the fuse 3 has a lower melting point in the product of this embodiment due to the tungsten content than that in the product of Comparative Example, and this remarkably reduces energy at the time of fusion and evaporation in comparison with the product of Comparative Example 1.
As described above, the product of this embodiment can by far greatly reduce the energy necessary for fusion than that required by the product of Comparative Example 1. Therefore, the product of this embodiment can drastically reduce the thermal stress imparted to various films constituting the semiconductor device, particularly, the SiN film 8, and it is expected that cracks of the SiN film 8, etc., can be drastically reduced.
In order to evidence the assumption described above, the minimum voltage capable of fusing without the occurrence of cracks was examined for the product of this embodiment and the product of Comparative Example 1 by changing the impressed voltage. The occurrence of cracks was examined by a Caros test. By the way, when the impressed voltage to the fuse 3 is lowered, the feed current becomes small, and thermal energy occurring at the fuse portion per unit time becomes small. Therefore, the temperature rise rate of the fuse becomes gentle, and the time necessary for fusing becomes elongated. As a result, the quantity of heat of the fuse portion transferred to the PSG and the SiN film 8 by heat conduction becomes great, and cracks are more likely to occur in the SiN film 8. In other words, energy necessary for fusing, which increases due to a low voltage, is believed to correspond to energy diffused to the PSG and the SiN film 8.
When a high voltage is impressed, on the contrary, the temperature rise rate of the fuse 3 is high and fusion occurs within a short time. Consequently, the diffusion quantity of the resulting energy to the PSG and the SiN film 8 becomes small, and fusion of the fuse 3 can be effectively conducted.
When the application of the present invention to practical devices is taken into consideration, it is advantageous that the fusing voltage of the fuse is low, because when a large voltage is applied, other devices are likely to be destroyed in some cases.
The results of experiments revealed that the maximum fusible voltage without the occurrence of cracks was 30 V in the product of this embodiment and was 75 V in the product of Comparative Example 1. Accordingly, in the product of this embodiment wherein fusion occurs at a low temperature, the occurrence of cracks can be suppressed even when a low voltage is impressed for fusing.
COMPARATIVE EXAMPLE 2
In the semiconductor device, the product of Comparative Example 2 is produced in the same way as the product of Comparative Example 1 with the exception that a tungsten oxide film 6 is interposed between the fuse 3 and the PSG film 7 instead of directly adding tungsten to the thin film resistor. FIG. 5 shows the section of the semiconductor device so produced. The fusion characteristics of this Comparative Example 2 is a mixture between the characteristics of the product of the embodiment of the present invention and those of the product of Comparative Example 1. Though energy necessary for fusing is lower than that of the product of Comparative Example 1, the product of Comparative Example 2 obviously requires greater energy for fusing than the product of the embodiment of the present invention.
The maximum fusible voltage without the occurrence of cracks was 50 V in the product of this Comparative Example 2, and was higher than 30 V in the product of the embodiment of the present invention.
In comparison with Comparative Example 2 wherein the tungsten oxide is laminated on the chromium-silicon thin film resistor, the ternary alloy prepared by adding tungsten to the chromium-silicon thin film resistor of this embodiment, that is, the chromium-silicon-tungsten thin film resistor, can further reduce energy required for fusing.
As a result of the studies on the energy reduction effect made by the present inventors, it has been found out that in the case of the thin film resistor according to this embodiment, the intermetallic compound (CrSi 2 ) having a low melting point starts occuring at arbitrary positions of the thin film resistor substantially simultaneously with heating. It is therefore presumed that the thin film resistor is heated and fused instantaneously at a low level of fusing energy.
In contrast, the thin film resistor of Comparative Example 2 is not heated and fused so instantaneously as in this embodiment. It is presumed that the tungsten oxide is molten from the interface of chromium, silicon and tungsten oxide and this melting phenomenon greatly affects fusing. Further studies on this phenomenon reveal the following fact. In the structure of Comparative Example 2, as also disclosed in Japanese Unexamined Patent Publication (Kokai) No. 6-61353, the intermetallic compound (CrSi 2 ) having a low melting point starts being formed gradually from near the interface to which the tungsten oxide mixes, but a certain period of time is necessary before the whole tungsten oxide is molten into the thin film resistor. Therefore, lowering of the melting point of the thin film resistor is impeded immediately after heating, due to the portions unmixed with the tungsten oxide, and this impedes sufficient lowering of the melting point of the thin film resistor.
As described above, the fuse device of this embodiment can be fused at a lower level of energy than the prior art devices, and has less occurrence of cracks but high reliability. Further, the minimum voltage that can be applied is low and the input energy quantity is small. Therefore, the fuse device is easier to handle.
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A fuse fusible type semiconductor device capable of reducing energy required for fusing and a production method of the semiconductor device. In a semiconductor device equipped with a heat-fusible thin film resistor, the thin film resistor formed on a substrate 1 through an insulating film 2 is made of chromium, silicon and tungsten, and films 7 and 8 of a insulator including silicon laminated on the upper surface of the fusing surface, aluminum films 5 are disposed on both sides of the fusing surface and a barrier film 4. This semiconductor device is produced by a lamination step of sequentially forming a first insulating film 2, a thin film resistor 3, a barrier film 4 and an aluminum film 5 on a substrate 1 for reducing drastically fusing energy, an etching step of removing the barrier film 4 and the aluminum film 5 from the fusing region 31 of the thin film resistor 3, and an oxide film formation step of depositing the insulator including silicon films 7 and 8.
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TECHNICAL FIELD
[0001] The present invention relates to torque transferring devices used within vehicle transmissions, and, more particularly, to a composite clutch shaft assembly.
BACKGROUND OF THE INVENTION
[0002] Clutch shafts for use in vehicle transmissions are well known in the art. Generally, a shaft extends from a clutch hub and supports a gear. A clutch selectively engages teeth formed within the clutch hub to selectively transfer torque between the clutch and the gear. The vehicle transmission may experience an audible noise or “squawk” when the clutch is applied or released at elevated temperatures. This “squawk” may be a result of instability of the clutch hub and shaft system. The spring rate and inertia of the system may be such that the shaft behaves as a one degree of freedom system, with the clutch hub and clutch plates acting as the inertia and the output end of the shaft acting as the ground.
[0003] The hub is subject to the friction force of the slipping clutch, which can exhibit a negative coefficient of friction versus slip speed characteristic when the clutch becomes hot, aged, or subject to high unit loading. This negative friction slope emulates negative damping, which may cause the one degree of freedom system to become unstable if the negative slope and the positive internal damping of the shaft sum to a negative value. In such situations, the oscillation of the hub (inertia) across the shaft (spring) will increase exponentially until a non-linearity is encountered. Such non-linearities may be that the clutch plate splines no longer contact the hub or that the rotational velocity of the clutch moves the friction characteristics out of the negative slip zone. Engineers have improved “squawk” characteristics in the past by increasing the diameter of the shaft, increasing the inertia of the hub, increasing heat extraction from the clutch pack, increasing clutch surface area, and/or the addition of a damper. The damper may be either a coulomb type or a tuned mass damper.
SUMMARY OF THE INVENTION
[0004] Provided is a composite clutch shaft having a hub and a shaft extending from the hub. The shaft has a core portion disposed within a generally tubular outer portion. The core portion has a higher internal damping characteristic than the outer portion. The core portion may be either solid or hollow. Additionally the core portion may be formed from grey iron and press fit into the outer portion which may be formed from steel. The core portion may extend substantially the entire length of the shaft.
[0005] Also provided is a composite clutch shaft including a hub having a shaft extending therefrom. The shaft is formed from a heat treatable material and the shaft has a heat treated outer portion and a non-heat treated core portion. The non-heat treated core portion has a higher internal damping characteristic than the heat treated outer portion.
[0006] The above features and advantages and other features and advantages of the present invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a sectional perspective view of a composite clutch shaft assembly broken away to show a core portion within an outer portion of a shaft portion according to the present invention;
[0008] FIG. 2 is a side view of the composite clutch shaft assembly of FIG. 1 , showing the core portion in phantom;
[0009] FIG. 3 a is a schematic cross sectional view of one embodiment of the shaft portion of the composite clutch shaft assembly taken along line A-A of FIG. 2 ;
[0010] FIG. 3 b is a schematic cross sectional view of a second embodiment of the shaft portion of the composite clutch shaft assembly also taken along line A-A of FIG. 2 ;
[0011] FIG. 4 a is a schematic cross sectional view of a third embodiment of the shaft portion of the composite clutch shaft assembly also taken along line A-A of FIG. 2 ; and
[0012] FIG. 4 b is a schematic cross sectional view of a fourth embodiment of the shaft portion of the composite clutch shaft assembly also taken along line A-A of FIG. 2 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0013] Referring to FIGS. 1 and 2 , a composite clutch shaft or composite clutch shaft assembly according to the present invention is shown at 10 . The composite clutch shaft assembly 10 comprises an annular hub or hub portion 12 with a shaft or shaft portion 14 extending therefrom. The hub 12 and the shaft 14 may be formed integrally as a single piece or may be two pieces joined together. In the preferred embodiments, the shaft assembly 10 is a fourth clutch shaft for a vehicle transmission. As such, the hub 12 is configured to be matable with a clutch (not shown), while the shaft 14 is configured to support a gear (not shown). However, it should be appreciated that the present invention may be used to transfer torque in a variety of applications within the inventive concept.
[0014] The hub 12 includes a circumferential wall 16 having a plurality of teeth 18 protruding radially therefrom. The plurality of teeth 18 preferably extend about the entire perimeter of the circumferential wall 16 . Lubricant openings 20 extend through at least some of the plurality of teeth 18 to allow lubricant to flow into and out of the composite clutch shaft 10 . The hub 12 is preferably configured to engage the clutch within the vehicle transmission. When the clutch is applied, splined clutch plates transfer torque from the clutch to the hub 12 for substantially unitary rotation therewith.
[0015] The shaft 14 extends from the hub 12 to a splined end portion 22 . Splines 24 are formed on an outer surface 26 of the shaft 14 at the splined end portion 22 . In the preferred embodiment, the splines 24 extend around the entire outer surface 26 of the shaft 14 . The splines 24 are preferably configured to support a gear. Preferably, the splines 24 are induction hardened following formation, thereby reducing spline degradation caused by the gear.
[0016] With reference to FIG. 3 a, the shaft 14 of the present invention includes a generally tubular outer portion 28 having an inner core portion 30 disposed therein. In the preferred embodiment, the core portion 30 will extend substantially the length of the shaft 14 from end 31 , as shown in phantom in FIG. 2 . Those skilled in the art will recognize that the core portion 30 may extend for less than the length of the shaft 14 as design constraints of the composite clutch shaft 10 dictate. Preferably, the core portion 30 is press fit into the tubular outer portion 28 ; however, those skilled in the art will recognize other methods operable to retain the core portion 30 relative to the outer portion 28 , such as bonding or staking. FIG. 3 a illustrates one embodiment of the present invention in which a cross sectional view of the shaft 14 illustrates the outer portion 28 and the inner core portion 30 . The inner core portion 30 may be solid or hollow. FIG. 3b illustrates a second embodiment of the present invention in which a cross sectional view of the shaft 14 illustrates a core portion 30 ′ defining a hollow center 33 .
[0017] An exemplary embodiment of the shaft 14 in FIGS. 3 a and 3 b would be to form the core portions 30 and 30 ′ from a stiff material with a high internal damping characteristic, such as grey iron. Grey iron core portions, such as 30 and 30 ′, would be press fit into a steel outer portion, such as 28 , having a known or predetermined internal damping characteristic. The grey iron has approximately half the stiffness of steel, but has nearly eighty times the internal damping of quenched and tempered high carbon steel having a martensite microstructure. The damping characteristic of the shaft 14 is thus improved compared to hollow or solid shafts formed from a single material. This increased damping characteristic is achieved without changing the exterior dimensions of the shaft 14 or significantly increasing stresses within the steel constituting the outer portion 28 .
[0018] A third and fourth embodiment of the present invention is shown respectively in FIG. 4 a and 4 b. In FIG. 4 a there is shown a cross section of a shaft 14 ′. In this embodiment, the shaft 14 ′ is formed from a heat treatable material, such as steel. In this embodiment, the outer portion 28 ′ is formed by heat treating the shaft 14 ′ sufficiently to a predetermined depth while leaving core portion 30 ″ unaffected. By doing so, the core portion 30 ″ will maintain high internal damping compared to the outer portion 28 ′. FIG. 4 b is a cross sectional view of the shaft 14 ′ illustrating a core portion 30 ′″ defining a hollow center 33 , similar to that shown in FIG. 3 b.
[0019] Exemplary of the embodiments shown in FIGS. 4 a and 4 b, the shaft 14 ′ may be made of steel. The shaft 14 ′ may be sufficiently heat treated to form a martensite microstructure in the outer portion 28 ′ while the core portions 30 ″ and 30 ′″ will maintain a ferrite microstructure, which has approximately eight times the internal damping of steel with a martensite microstructure. The shaft 14 ′ will have a greater damping ability than a shaft having a martensite microstructure for both the outer portion 28 ′ and the core portions 30 ″ and 30 ′″.
[0020] Those skilled in the art will recognize that the relative radial thicknesses of the outer portions 28 , 28 ′ and the core portions 30 , 30 ′, 30 ″, and 30 ′″ will be dictated by engineering constraints such as torsional loading on the shaft 14 , 14 ′. The composite clutch shaft 10 of the present invention may reduce unwanted noise and vibration within the power transmission by increasing the damping effectiveness of the shaft 14 and 14 ′.
[0021] While the best modes for carrying out the invention have been described in detail, it is to be understood that the terminology used is intended to be in the nature of words and description rather than of limitation. Those familiar with the art to which this invention relates will recognize that many modifications of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced in a substantially equivalent way other than as specifically described herein.
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A composite clutch shaft assembly has an annular hub with a shaft extending therefrom. The shaft has a generally tubular outer portion and a core portion. The core portion has higher internal damping than the outer portion, thereby improving the vibration and noise damping characteristics of the clutch shaft while having little or no effect on the external dimensions of the clutch shaft.
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RELATED APPLICATIONS
This application is a continuation of application Ser. No. 07/697,972 , filed May 10, 1991, now abandoned, which is a continuation-in-part application of U.S. application Ser. No. 07/675,293, filed Mar. 26, 1991 and entitled "Cut Resistant Strap", which in turn is a continuation-in-part application of U.S. application Ser. No. 07/568,270, filed Aug. 15, 1990, now abandoned and also entitled "Cut Resistant Strap". The entire disclosure of each of the foregoing applications is expressly incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates generally to straps for supporting or restraining various objects, and more particularly to a woven strap having an improved edge.
BACKGROUND OF THE INVENTION
Woven webbings have long been used as straps and slings for luggage handles, child restraints, animal harnesses, and for securing or supporting various objects. A typical prior art, woven strap is shown in FIG. 1. The woven strap 10 typically is formed by weaving a tube from warp yarns 12, 14 and a weft yarn 16, and then flattening the tube to form a 2-ply woven strap. The two plies 18, 20 are woven together by binder yarns 22. Stuffer yarns 24 typically are sandwiched between the two-plies 18, 20 for increasing the overall strength and/or thickness of the woven strap 10.
When such straps are used as a cargo-securement device such as a cargo tie-down or sling, the edges of the straps often come into contact with sharp objects which can abrade and/or cut the edges, causing the strap to tear or break. U.S. Pat. No. 4,856,837 discloses a two-ply woven cargo sling designed to resist tearing or breaking of the sling. According to the '837 patent, the edges of the sling are strengthened relative to the central region by weaving vinyl-coated yarns along the edges. These strengthened yarns are said to improve the sling by making the edges more resistant to abrasion and cutting. This approach has the drawback of requiring special, strengthened material along the edges of the sling, thereby increasing the cost of manufacturing the sling. It also has the drawback of stiffening the edges of the sling relative to the central region, thereby making the sling less suitable for human or animal contact (if such a sling were to be used in certain contexts other than as slings).
Accordingly, it is an object of the invention to provide an improved strap of woven webbing having edges which effectively resist abrasion and cutting.
It is a particular object of the invention to provide an improved tie-down, load restraint web or sling having cut resistant edges.
Another object of the invention is to provide a strap of woven webbing having soft, flexible edges suitable for contact with a human or animal.
Another object of the invention is to provide a strap of woven webbing that has uniform elongation properties across its cross-section.
Yet another object of the invention is to provide a strap of woven webbing having the foregoing properties which is simple and economical to manufacture.
SUMMARY OF THE INVENTION
These and other objects are achieved by the invention which provides a strip of woven material having increased resistance against cutting and abrading, while also having added softness along its edges thereby enhancing safety and comfort when the strip contacts humans or animals.
According to one aspect of the invention, a length of woven material defines an edge relative to a central region, the edge being adapted to deform when a force transverse to the length is applied to the edge. Preferably there are two edges. The edges are constructed and arranged to be softer or more deformable than the central region between the edges. Surprisingly, even though the edges are softer or more deformable, the edges have improved cut resistance.
In one preferred embodiment, a strip of woven web material has a nontubular central region defining a length, and a tube attached along the length defining an edge. The tube may be woven of the same material as the central region. The tube may be filled or unfilled.
In one particularly preferred embodiment, the strip of woven material has a break strength of at least about 4500 lbs., and most preferably about 10,000 lbs. or more. In this embodiment, it also is preferred that the strip be made of polyester, nylon or bulked nylon, have a width of at least 13/4 inches, and have a weight of at least 15 lbs. per 100 yards. Such devices are particularly suitable as cargo-securement straps.
According to another aspect of the invention, a method for making a strip of woven web material as defined above is provided. A tube is continuously woven from warp and weft fibers. The tube is flattened and opposing plies are bound to form a two-ply central region and at least one tubular region defining an edge. This tubular edge is capable of deforming relative to the central region when a force is applied to the edge transverse to the length.
According to still another aspect of the invention, a method for securing cargo to a support for the cargo is provided. Strips of the web material of the invention are used to tie-down or otherwise secure cargo to a cargo support. Cargo secured by such web material also represents an aspect of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing objects and advantages of the present invention will be more clearly understood in connection with the the accompanying drawings in which:
FIG. 1 is a sectional view of a prior art strip of webbing material;
FIG. 2 is a perspective view of a strip of woven webbing material made according to the invention and held under tension with a force being applied transverse to the length;
FIG. 3 is a cross-sectional view taken along line 3--3 of the woven webbing of FIG. 2;
FIG. 4 is a sectional view taken along line 4--4 of the woven webbing of FIG. 2;
FIG. 5 is a sectional view of a second embodiment of the invention; and
FIG. 6 is a schematic illustration of strips of woven webbing material according to the invention used to secure cargo to a truck;
FIG. 7 is a perspective view of a tie down including hardware;
FIG. 8 is a perspective view of a sling including hardware;
FIG. 9 is a perspective view of a sling having looped ends, but without hardware;
FIG. 10 is a diagram of the chain draft for the weave according to Example I;
FIG. 11 is a diagram of the loom draft for the weave according to Example I;
FIG. 12 is a diagram of the chain draft for the weave according to Example II; and
FIG. 13 is a diagram of the loom draft for the weave according to Example II.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 2, a woven webbing strap 40 according to the invention is shown under tension and with a force being applied transverse to the length of the strap 40. The force is applied by a knife 42. As can be seen, the edge 44 of the strap 40 deforms relative to the central region 46 when the knife 42 is contacted against the edge 44 using a force transverse to the length of the strap 40. This deformation allows the edge of the strap to `give` under the force of the knife 42, thereby causing the edge 44 of the strap 40 to absorb some of the force of the contact with the knife 42. The cut resistance of the edge 44 is thus improved. At the same time, the edge is softer due to its ability to `give` when a force is applied to the edge. Because the edge is softer (rather than stiffer as is characterized by the prior art cut resistant edge), it is less likely to cut or injure a human or animal when the strap is under tension and is put to uses involving contact with human or animal skin (e.g., seat-belts, child restraints, harnesses).
Referring to FIG. 3, the woven strap 40 has an upper ply 48 and a lower ply 50. The upper and lower plies 48, 50 are formed of warp yarns 52 continuously woven with weft yarns 54. The upper and lower plies 48, 50 are bound together only along the central region 46 by binder yarns 56 in a conventional manner. The upper and lower plies are unbound along their periphery, thereby forming a pair of tubes 60 defining the opposing edges of the strap 40. Stuffer yarns 58 are sandwiched between the upper and lower plies 48, 50 and are bound in place in the central region 46 by the binder yarns 56. The stuffer yarns 58 also are contained in the tubes 60.
For the purposes of this invention, for two-ply webs having a width greater than or equal to one inch, a tubular edge is present when the width of the tubular edge, defined as the distance when the two plies are in face to face relation (i.e. the tube is flattened) between the outermost edge 53 of the web and the binder yarn 56' closest to the outermost edge 53, is at least about 3/16 of an inch, and preferably is at least 1/4 of an inch. Alternatively, a tube may be considered present if the width of the tubular edge substantially exceeds the average distance between the binders in the web.
For the purposes of this invention, for two-ply webs, a nontubular central region is one having at least six binders per inch, and preferably at least 12 binders per inch. Alternatively, a nontubular central region is present if the width of the tubular edge substantially exceeds the average distance between the binders in the web.
It also is intended that strips of webbing having tubular edges and one-ply central regions are within the scope of the invention.
For webs having a pair of tubes along opposing edges, preferably the combined width of the tubes is equal to at least about 25% of the overall width of the web. Moreover, preferably the number of warp ends in the tubes as a percentage of the total warp ends in the web varies in a range from about 25% to 65%.
The following table illustrates examples of webbing having a pair of tubes along opposing edges, indicating the overall width of the web, the width of the individual tubes and the percentage represented by the combined width of the tubes vs. the overall width of the strap. The table also indicates the total number of warp ends in the web, the combined total number of warp ends in the two tubes and the percentage represented by the combined total of warp ends in the tubes vs. the total number of warp ends in the web.
__________________________________________________________________________WEB TUBE PERCENTAGE TOTAL ENDS IN PERCENTAGEWIDTHWIDTH TUBES/WEB ENDS TUBES COMBINED TUBES/TOTAL__________________________________________________________________________4" 1/2" 25% 217 77 35%4" 1/2" 25% 217 77 35%2" 1/4" 25% 112 47 42%13/4"3/8" 42% 165 56 34%2" 1/4" 25% 105 37 35%13/4"5/16" 36% 236 61 26%11/2"7/32" 29% 194 80 41%1" 1/4" 50% 169 85 50%3/4" 7/32" 58% 138 90 65%5/8" 1/8" 40% 106 58 55%__________________________________________________________________________
The strap 40 is formed preferably by continuously weaving a tube from the warp yarns 52 and weft yarns 54, and then flattening the tube to form a two-ply strap. Binder yarns 56 are woven continuously to bind the two plies to one another only in the central region 46 of the strap 40. The upper and lower plies 48, 50 of the strap 40 are not woven to one another by binder yarns 56 along their edges, and therefore a pair of tubes are formed along opposing edges 44, 45 of the strap 40. These tubes may include various materials such as stuffer yarns 58 or other reinforcing or strengthening materials, or may be unfilled (FIG. 5). Virtually any material may be included in the tubes 60, ideally so long as that material does not significantly affect the ability of the edges to deform relative to the central region when a force is applied to the edges transverse to the length of the strap. It will be understood, however, that if the tubes carry a strengthening material, the ability of the tubes to deform may be compromised somewhat. In this instance, certain benefits of the invention may not be achieved, although others will be achieved, and such embodiments are intended to be encompassed.
The strap 40 may be woven with conventional machinery used for manufacturing woven straps. Such machinery is well known to those of ordinary skill in the art and is commercially available. In essence, the prior art manufacturing technique may be followed, with the exception that the binder yarns which typically are present at the edges of a two-ply strap are removed so that a strap having tubes at opposing edges is formed.
The straps of the invention are particularly useful in situations where cut resistance is important, such as in tying down cargo with straps or supporting cargo with a sling. As used herein, the term cargo securement strap is intended to include tie downs, such as motorcycle tie downs, cargo tie downs, snowmobile tie downs, boat tie downs, car top tie downs, vehicle securement tie downs and tie downs used with a tow dolly. Generally, a tie down is a device used to secure cargo being transported such as on a trailor, train, boat, plane, etc. The term also is intended to include a tow-straps, winch straps and slings. Cargo securement straps are of defined length, depending upon the particular usage, and it should be understood that length may vary widely. Referring to FIG. 6, straps 40 according to the invention are shown securing a load of stacked logs 62 to the cargo-support bed 64 of a truck 66.
A preferred embodiment of the invention is a tie-down web having a width of 2 inches and made of polyester fibers. The webbing has a weight per hundred yards of about 19 lbs., an elongation at 60% of break strength of about 11% and a break strength of about 10,000 lbs. Another preferred embodiment 8s a tie-down web having a width of four inches and made of polyester fibers. This tie-down web has a weight per 100 yards of about 39 lbs., an elongation at 60% break strength of about 12% and a break strength of about 20,000 lbs. These preferred 2 inch and 4 inch tie-down webs have warp yarns of 1,000 denier, 3-ply; binder yarns of 1,000 denier, 1-ply; stuffer yarns of 1,000 denier, 7-ply; and filling yarns of 1,000 denier, 1-ply.
A preferred sling webbing according to the invention has a width of 2 inches and is formed of nylon. It has a weight per 100 yards of about 26 lbs., an elongation at break strength of about 22%, and a break strength of about 13,600 lbs. The sling webbing is made of yarns having the following characteristics: warp yarns of 1680 denier, 1 ply; binder yarns of 1680 denier, 1 ply; stuffer yarns of 1680 denier, 1 ply; and filling yarns of 1680 denlet, 1 ply.
Yet another preferred embodiment is a cargo control strap having a width of two inches and formed from bulked nylon/polyester. The cargo control strap has a weight per 100 yards of about 12 lbs., an elongation at 60% break strength of about 10%, and a break strength of 4,500 lbs. The cargo control strap is formed of yarns having the following characteristics: bulked nylon warp yarns of 1,900 denier, 1 ply; bulked nylon binder yarns of 1,900 denier, 1 ply; polyester stuffer yarns of 1,000 denier, 2-ply; and polyester filling yarns of 1000 denier, 1-ply.
Cargo securement straps and in particular tie-downs are typically used with securement hardware such as end fittings, flat hooks, delta rings, "J" hooks, "S" hooks and snap hooks. Such securement hardware also includes buckles and rachet assemblies. Such hooks and attachment hardware typically define an opening through which the webbing is passed whereby the webbing may be turned back upon itself and sewn to attach the hardware to the webbing.
Slings are used for lifting heavy objects. Slings may be used with or without hardware. Hardware typically used with slings includes chokers, triangular rings, and bridal sling hardware. In certain slings, hardware is entirely absent. Instead, the end of the webbing simply is turned back upon itself and sewn to form a loop which can be used for mechanical engagement purposes. Such looped ends include flat-eye ends, reversed eye ends and twisted eye ends.
FIG. 7 shows a tie-down having attached to it securement hardware. At one end of the tie-down is a flat hook 80 and at the other end of the tie-down is a delta ring 82. In the middle of the tie-down and connecting the strips of woven webbing 84 according to the invention is a rachet assembly 86.
FIG. 8 shows a sling according to the invention including securement hardware. The sling includes a strip of woven webbing 88 according to the invention with a choker 90 at one end of the sling and a triangle 92 at the opposite end.
FIG. 9 depicts a sling including a strip of woven material 94 according to the invention with looped ends 96 at opposite ends of the sling.
The improvement in cut resistance of the strap of the invention is surprising. The prior art approach to improving cut resistance was to add material to the edges and in particular add a stronger, reinforced material to the edges. According to one aspect of the invention, material has been removed from the edges and the edges have been made in some respects weaker than the central region. The strap of the invention thus is characterized in certain embodiments by a central region having a greater number of fibers per unit area of cross-section as compared to the same unit area of cross-section for the edges.
EXAMPLE I
Tie-Down
A 4 inch tie-down was woven in general as described above. The tie-down had a 3 inch, 2-ply, central nontubular portion and a pair of 1/2 wide tubes woven lengthwise to the central nontubular portion. The tubes were filled, with two ends floating freely within the tube formed along the needle edge and four ends floating freely within the tubes along the opposite edge. The tie-down had a weight per 100 yards of about 38 lbs., and elongation at 60% of break strength of less than 18% and a break strength of about 20,000 lbs. The yarns were as follows: The warp yarn was polyester, 1000 denier, 3-ply; the binder yarns were polyester, 1000 denier, 1-ply; the stuffer yarns were polyester, 1000 denier, 7-ply; the weft yarns were polyester, 1000 denier, 1-ply; and the catch cord was Nylon, 420 denier. The yarn strength of the polyester was a minimum of 8.9 grams per denier and the yarn strength of the Nylon was at least 7.7 grams per denjer. The polyester yarn had a twist of 21/2 turns per inch and an elongation at break of 14%.
The type of weave for the body was as follows: A 3-1 regular weave for the warp; a 1-1 weave for the binder; and a 1-1 weave for the stuffer (floating, reverse of binder). The edge weave was a 3-1 regular weave for the warp and a 1-1 weave for the stuffer. The edge contained no binder. To manufacture the weave, the reed size was 10.5 dents per inch and the reed type was M-2. The body had 140 warp end, 37 binder ends, 90 stuffer ends, and 15 weft picks (finishes to 16 picks). The needle edge had 39 warp ends and two stuffer ends. The opposite edge had 38 warp ends and four stuffer ends. The chain draft is depicted in FIG. 10. The gears are shown on the vertical axis and the harnesses are shown on the horizontal axis. Harness No. 2 is for the binder, harnesses 3-10 are for the regular weave, and harnesses 11 and 12 are for the two stuffers. Harness 1 was skipped, and X indicates "up pick" and a "." indicates a "down pick". The loom was an N.C. High Shed Loom by Mueller, Germany.
FIG. 11 depicts the loom draft. The body is indicated by bracket 106, the needle side tube is indicated by bracket 108 and the opposite tube is indicated by bracket 110. The numbers contained within circles refer to stuffers. B refers to binder and N refers to needle side.
The tie-down after being woven was treated with the following dye composition. 12 lbs. of Eccobrite Yellow, Eastern Color, RI; 120 lbs. of an Polyerethene Emulsion sold under the trade name Solucote 1016, Soluol, RI; 120 lbs. of an Acrylic Emulsion sold under the trade name Duraseal P-23, Scholler, PA; and 6 lbs. of an Alkylaryl polyether alcohol sold under the trade name Orcowet PA, Organic, RI and water sufficient to form a 280 gallon mix.
The material was woven on the loom to a width of 47/16 inches wide, and had a width of 4 inches after the following treatment. The woven material was introduced into a padder containing the dye composition. The dwell time in the padder was 2 seconds and the dwell temperature was room temperature (20% pickup was achieved). The material then was cured and dried in a hot air dryer at a temperature of 325° F. for 8 minutes in order to fix the dye. The speed of the material both at the padder and before entrance to the oven was 12.6 yds/min. This treatment provided color, stiffness and enhanced abrasion resistance.
EXAMPLE II
Vehicle Securement
A 2 inch vehicle securement webbing was woven in general as described above. The securement had a 11/2 inch, 2-ply, central non-tubular portion and a pair of 1/4 inch wide tubes woven length-wise to the central non-tubular portion. The tubes were hollow. The securement webbing had a weight per 100 yards of about 20 pounds, an elongation at 50 percent of break strength of less than 18 percent and a break strength of about 12,000 pounds. The yarns were as follows: the warp yarn was polyester, 1000 denier, 3-ply; the binder yarns were polyester, 1000 denier, 1-ply; the stuffer yarns were polyester, 1000 denier, 7-ply; the weft yarns were polyester, 1000 denier, 1-ply; and the catch cord was nylon, 210 denier. The yarn strength of the polyester was a minimum of 8.9 grams per denier and the yarn strength of the nylon was at least 7.7 grams per denier. The polyester yarn had a twist of 21/2 turns per inch and an elongation at break of 14 percent.
The type of weave for the body was as follows: a 3-1 regular weave of the warp, a 1-1 weave for the binder; one binder with a 2-2 weave on the edge opposite the needle, being the last binder before the tube; and a 1-1 weave for the stuffer (floating, reverse of binder). The edge contained no binder or stuffer. To manufacture the weave, the reed size was 10 dents per inch and the reed type was M-2. The body had 65 warp ends, 19 binder ends, 72 stuffer ends and 15 weft picks (finishes to 16 picks). The needle edge had 22 warp ends. The opposite edge had 25 warp ends. The chain draft is depicted in FIG. 12. The gears are shown on the vertical axis and the harnesses are shown on the horizontal axis. Harness No. 2 was for the binder, Harnesses 3-6 were for the regular weave, Harnesses 7-10 were for the stuffers, and Harness No. 11 was for the 2-2 binder. Harness 1 was skipped. An X indicates "up pick" and a " ." indicates "down pick". The loom was a NC-280 Loom by Mueller, Germany.
FIG. 13 depicts the loom draft. As was the case with FIG. 11, the body is indicated by bracket 106, the needle side tube is indicated by bracket 108, and the opposite side tube is indicated by bracket 110. B refers to binder and N refers to needle side.
The vehicle securement webbing after being woven was treated with the following dye composition. 2000 grams of Eccobrite Yellow, Eastern Color, RI; 100 pounds of a 45 percent polyurethene emulsion resin sold under the trade name Solucote 1017, Soluol, RI; 80 pounds of a 33 percent polymeric paraffin wax emulsion sold under the trade name Nomar 70, Michelman Inc., OH; and 1000 grams of a 25 percent Alkylaryl Polyether Alcohol sold under the trade name Orocwet PA, Orangic, RI and water sufficient to form a 100 gallon mix.
The material was woven on the loom to a width of 21/8 inch, and had a width of 2 inches after the following treatment. The woven material was introduced into a padder containing the dye composition. The dwell time in the padder was 2 seconds and the dwell temperature was room temperature (20 percent pick up was achieved). The material then was cured and dried in a hot air dryer at a temperature of 350 degrees F. for 8 minutes in order to fix the dye. The treatment provided color, improved abrasion resistance against sharp objects, and improved flat abrasion.
It should be understood that the preceding is merely a detailed description of certain preferred embodiments; and it will be apparent to those of ordinary skill in the art that various modifications and equivalents can be made without departing from the spirit or scope of the invention. For example, although the preferred embodiment describes edges woven of the same material as the central region of the strap, the edges also may be woven of a different material. If the edges are formed of a material that is stronger than the material of the central region, then the edges still must be configured in a manner such that the edge deforms relative to the central region when a force is applied transverse to the length.
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A novel woven webbing having improved resistance to cutting is provided. The webbing has edges adapted to resist cutting by absorbing the initial impact of a force applied to the webbing edge. The woven webbing may have a nontubular central region and at least one tube attached along the length of the central region and defining at least one edge of the webbing.
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BACKGROUND
The cementing of a liner or a casing in a well is done to, among other things; prevent flow in an annular space between the liner or casing and the open borehole. It is common to perform several cementing operations within a single deep well. When additional drilling is required after a cementing operation has been completed in one section of the well, the cementing wiper plugs, landing collar and cement located at the bottom of the section of the well just cemented need to be drilled through before the drill bit can begin drilling into the earth formation again. Drilling through a landing collar can damage or dull a drill bit, can generate undesirable debris within the wellbore, and can delay drilling progress in the earth formation. Systems and methods that alleviate the foregoing concerns are well received in the industry.
BRIEF DESCRIPTION
Disclosed herein is a runnable member catcher. The catcher includes a body fixedly attachable within a tubular, the body defines inner radial dimensions that are smaller than portions of the body that are fixedly attached the body to the tubular, the body is configured to be structurally weakened upon exposure to an activation fluid to facilitate removal of the body.
Further disclosed herein is a method of removing a runnable member catcher. The method includes, exposing the runnable member catcher to an activation fluid, weakening the runnable member catcher with the activation fluid and drilling or milling out the runnable member catcher.
Further disclosed herein is a runnable member catching system. The system includes a tubular and a body fixedly attachable within the tubular and defining a seat sealingly engagable with a member runnable thereagainst, the body is configured to be structurally weakened upon exposure to an activation fluid to facilitate removal of the body.
BRIEF DESCRIPTION OF THE DRAWINGS
The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:
FIG. 1 depicts a cross sectional view of a runnable member catching system disclosed herein; and
FIG. 2 depicts a cross sectional view of the runnable member catching system of FIG. 1 with a runnable member engaged therewith.
DETAILED DESCRIPTION
A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.
Referring to FIGS. 1 and 2 an embodiment of a runnable member catching system disclosed herein is illustrated at 10 . The system includes a tubular 14 and a catcher 16 comprising in this embodiment of a body 18 , an insert 22 and a sleeve 24 , although in some embodiments the catcher 16 may be comprised of fewer parts such as the body 18 only, for example, which alternatively could have a tubular shape. The body 18 is fixedly attached to the tubular 14 by the insert 22 . The insert 22 may be a split ring, as shown herein, that engages in a recess 26 in an inner surface 30 of walls 34 of the tubular 14 and a recess 38 in an outer surface 42 of the body 18 . Alternately, the insert 22 may be engaged with one or both of the body 18 and the tubular 14 by other means such as threadable engagement, for example. The sleeve 24 is fixedly attached to the body 18 and is sealably engaged within the tubular 14 . The body 18 has a seat 50 that has a smaller radial dimension than that of the tubular 14 , and is sealingly engagable by a runnable member 54 shown in FIG. 2 as a wiper plug. The body 18 and optionally, the sleeve 24 and the insert 22 are made of a material that is structurally weakened in response to being exposed to an activation fluid. This weakening allows for easier removal of the body 18 , the sleeve 24 and the insert 22 by processes such as drilling or milling, for example.
In one embodiment of the system 10 , the body 18 , the insert 22 and the sleeve 24 are manufactured from a high strength controlled electrolytic metallic material and are degradable when exposed to an activation fluid such as brine, acid, aqueous fluid or combinations of one or more of these. For example, a variety of suitable materials and their methods of manufacture are described in United States Patent Publication No. 2011/0135953 (Xu et al.), the entire Patent Publication of which is hereby incorporated by reference in its entirety.
The runnable member catching system 10 is employable in applications to allow the runnable member 54 to be caught at a known location within the tubular 14 where the catcher 16 is positioned. An example of such an application is during a downhole cementing operation wherein cement is pumped down through the tubular 14 and back up in an annular space 55 defined between the tubular 14 and an open borehole 56 in an earth formation 57 . Such an operation includes using the runnable member 54 to separate cement 58 from another fluid such as by leading introduction of the cement 58 or following the conclusion of the cement 58 . The runnable member 54 being a wiper plug that includes a seal 62 that sealingly engages with the inner surface 30 of the walls 34 while being run therethrough, thereby separates the cement 54 from fluid on an opposing side of the wiper plug 54 therefrom. A second wiper plug 65 is configured to slidingly sealingly engage with a smaller tubular (not shown) possible located upstream of the tubular 14 . The second wiper plug 65 being also configured to sealingly engage with a bore 67 in the wiper plug 54 . In FIG. 2 the wiper plug 54 is shown in a position after having been caught by the body 18 , also known in this application as a landing collar, and is sealingly engaged at the seat 50 . The seal 62 is engaged with the inside of the sleeve 24 and has moved downstream beyond ports 66 in the sleeve 24 . Fluid is then able to flow around the wiper plug 54 by flowing through the ports 66 and through an annular space 70 defined between the sleeve 24 and the tubular 14 , then through openings 74 in the body 18 . In this manner the cement 58 is able to be pumped past the wiper plug 54 and the runnable member catching system 10 . Another wiper plug (not shown) may then follow the cement 58 until it abuts with the wiper plug 54 thereby halting any additional flow of the cement 58 .
In some embodiments the activation fluid may be electrically conductive thereby helping to establish an electrochemical reaction to facilitate degradation of the catcher 16 components. In some applications the activation fluid can be pumped to the catcher 16 and can even be the fluid separated from the cement 58 by the runnable member 54 .
While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.
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A runnable member catcher includes a body fixedly attachable within a tubular, the body defines inner radial dimensions that are smaller than portions of the body that are fixedly attached the body to the tubular, the body is configured to be structurally weakened upon exposure to an activation fluid to facilitate removal of the body.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a continuation-in-part of U.S. patent application Ser. No. 10/715,911 entitled “OPTICAL ARRANGEMENTS FOR HEAD MOUNTED DISPLAYS,” filed Nov. 18, 2003 now U.S. Pat. No. 6,989,935, the disclosure of which is hereby incorporated herein by reference.
PRIORITY
The present application claims priority to Hungarian Patent Application, Serial No. P 02 03993, Filed, Nov. 19, 2002, entitled “OPTICAL SYSTEM FOR A BINOCULAR VIDEO SPECTACLE,” the disclosure of which is hereby incorporated herein by reference.
TECHNICAL FIELD
The invention relates generally to visual displays and more specifically to optical arrangements for head mounted systems that use a single display.
BACKGROUND OF THE INVENTION
Head Mounted Displays (HMDs) are a class of image display devices that can be used to display images from television, digital versatile discs (DVDs), computer applications, game consoles, or other similar applications. A HMD can be monocular ( a single image viewed by one eye), biocular (a single image viewed by both eyes), or binocular (a different image viewed by each eye). Further, the image projected to the eye(s) may be viewed by the user as complete, or as superimposed on the user's view of the outside world. HMD designs must account for parameters such as image resolution, the distance of the virtual image from the eye, the size of the virtual image (or the angle of the virtual image), the distortions of the virtual image, the distance between the left and the right pupil of the user (inter pupillar distance (IPD)), diopter correction, loss of light from image splitting and transmission, power consumption, weight, and price. Ideally, a single HMD would account for these parameters over a variety of users and be able to display an image regardless of whether it was a stereo binocular image or a simple monoscopic image.
If the resolution of a picture on the HMD's internal display is 800×600 pixels, an acceptable size for the virtual image produced by the HMD's optics is a virtual image diameter of approximately 1.5 m (52″-56″) at 2 m distance which corresponds to approximately a 36° angle of view. To properly conform to the human head and eyes, the IPD should be variable between 45 mm and 75 mm. In order to compensate for near- and farsightedness, at least a ±3 diopter correction is necessary.
The use of only one microdisplay in the HMD (instead of using one for each eye) drastically reduces the price of the device. Typically, an arrangement for such a unit positions a microdisplay between the user's eyes. The image produced is then split, enlarged, and separately transmitted to each eye. There are numerous designs known in the art for beam splitting in single display HMDs with a center mounted display, but none are known that provide a solution that is cheap, light weight, small in size, and capable of displaying all varieties of images.
BRIEF SUMMARY OF THE INVENTION
Embodiments of the present invention present images produced by head mounted displays to a user by producing separate sub-images that are propagated through a plurality of optical sub-paths delivering the image to separate locations. Embodiments of the present invention hold constant the length of each optical sub-path during adjustments by coordinated the movements of the optical elements placed along the sub-paths.
Some embodiments utilize diffusers places in the optical sub-path onto which real images of the display are formed. By coordinating the lateral movement of eyepiece optics necessary to correct for inter-pupilar distances with proportional movement of the diffusers, embodiments of the present invention are thus capable of maintaining a constant length for the optical sub-paths.
The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized that such equivalent constructions do not depart from the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawing, in which:
FIG. 1 illustrates a top view of a head mounted display arranged according to an embodiment of the present invention;
FIG. 2 illustrates a prospective view of a head mounted display arranged according to an embodiment of the present invention;
FIG. 3A illustrates a prospective view of a head mounted display arranged according to an embodiment the present invention showing diopter correction;
FIG. 3B illustrates a prospective view of the head mounted display of FIG. 3A showing the simultaneous movements utilized to make the IPD adjustment; and
FIGS. 3C and 3D illustrate a prospective view of the head mounted display of FIG. 3A showing the specific gear arrangements that can perform the linked movements of FIG. 3A .
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a top view of head mounted device 100 arranged according to an embodiment of the present invention. Sub-image creation section 101 , within device 100 , creates a plurality of sub-images from a single image source into a plurality of optical sub-paths. Display 110 can be any suitable apparatus or screen operable to display a visual image of data, such as a liquid crystal display (LCD) screen. Display 110 is situated along a display axis 111 , which, in the embodiment shown, is normal to the screen of display 110 and perpendicular to facial plane 170 of a user. Display 110 is designed to project a display image along optical path 112 . In the arrangement of section 101 , optical path 112 lies along display axis 111 . Display lens 115 is located along, and perpendicular to, optical path 112 , and has display lens focal point 124 . Display lens focal point 124 lies on optical path 112 , and section 101 is arranged such that display lens focal point 124 lies within splitter 120 . By focusing the display image before it is split, the splitting of volume of sub-image creation section 101 can be greatly reduced. A small splitting volume allows an embodiment to use small, light-weight splitting elements and allows HMD designs to include advantageous arrangements and additional optical elements that improve image quality and can increase the size of the image viewed by a user. The embodiment of FIG. 1 is arranged to produce an image through (approximately) collimated light emanated by (or being reflected from) display 110 , thus splitter 120 is placed proximate to display lens focal point 124 . The embodiments are not limited to this arrangement however, as splitter 120 should be arranged in the position most appropriate to the focused image. For example, if display 110 emits, transmits, or reflects non collimated light, the display image will be focused to a “point” that is not display lens focal point 124 , and embodiments will arrange splitter 120 in a position proximate to this focal area.
In embodiments using the arrangement of section 101 , splitter 120 is an asymmetric V-mirror splitter composed of a partially reflective surface 121 and a fully reflective surface 122 . The proximity of surfaces 121 , 122 will be dependent upon the size of splitter 120 and the amount of splitter volume reduction section 101 is arranged to produce. Section 101 is further arranged so that surface 121 and surface 122 share a common edge, and are arranged asymmetrically about display axis 111 . Section 101 can thus split a display image of display 110 into two separate display sub-images. The term sub-image is used to describe the multiple images of a display created by the various embodiments of the present invention. The sub-images of FIG. 1 contain all of the information of a display, but embodiments may use sub-images that contain only a portion of an image.
Upon striking partially reflective surface 121 , a portion of a display image is reflected along left-eye optical sub-path 140 , and becomes a left-eye sub-image. The portion of a display image not reflected by partially reflective surface 121 passes through and strikes fully reflective surface 122 , becoming a right-eye sub-image, which is reflected along right-eye optical sub-path 130 . The result is an identical left-eye sub-image and right-eye sub-image traveling in opposite directions and containing identical image information.
Left-eye sub-image will follow optical sub-path 140 and be channeled to left eye 146 of a user. Placed along optical sub-path 140 is left-eye reflector 142 , which is a fully reflective surface arranged to redirect left-eye optical sub-path 140 by 90° and into left eyepiece optics 145 . The right-eye sub-image will follow optical sub-path 130 and be channeled to right eye 136 of a user. Placed along optical sub-path 130 is right-eye reflector 132 , which is a fully reflective surface arranged to redirect right-eye optical sub-path 130 by 90° and into right eyepiece optics 135 . Right eyepiece optics 135 and left eyepiece optics 145 can be a single lens or a combination of several lenses designed to appropriately magnify a right-eye sub-image for viewing by right eye 136 of the user and a left-eye sub-image for viewing by left eye 146 of the user, respectively.
Eyepiece optics 135 and 145 are adjustable single lenses, but other embodiments may use multiple lenses or any other arrangement that appropriately focuses a right-eye sub-image and a left-eye sub-image for viewing by right eye 136 and left eye 146 , respectively. Further, although reflectors 142 , 132 of device 100 are depicted as mirrors, embodiments are not limited to the use of mirrors for redirecting an optical sub-path. Rather, prisms, partially reflective surfaces, polarizing beam splitters, or any other suitable arrangements can be used for redirecting an optical sub-path.
Device 100 is also capable of adjusting for the varying IPDs of different users through the synchronized movements of optical elements. Right eyepiece optics 135 and left eyepiece optics 145 can shift through movements 152 and 151 respectively to create IPD 150 a and IPD 150 b , when section 101 shifts through movement 155 . When IPD distance 150 a is changed to IPD 150 b , section 101 is simultaneously shifted toward facial plane 170 in movement 155 (downwards in the view of FIG. 1 ). When IPD 150 b is changed to 150 a , section 101 is simultaneously shifted away from plane 170 (upwards in the view of FIG. 1 ). These synchronized movements allow device 100 to adjust to accommodate for the entire range between IPD 150 a and 150 b while maintaining constant distances between surfaces 122 , 121 and eyepiece optics 135 , 145 along sub-paths 130 and 140 , respectively. Device 100 is also capable of diopter correction through additional adjustments of movement 153 of left eyepiece optics 145 and movement 154 of right eyepiece optics 135 .
FIG. 2 illustrates a prospective view of head mounted device 200 arranged according to an embodiment of the present invention. Head mounted device 200 includes section 101 , as described in relation to FIG. 1 , which operates to split a display image of display 110 into a left-eye sub-image traveling along left-eye optical sub-path 140 and a right-eye sub-image traveling along right-eye optical sub-path 130 . For device 200 , left-eye transition optics 243 are placed along left-eye optical sub-path 140 to adjust the left-eye sub-image for reflection by left-eye reflector 142 onto left-eye diffuser 244 . The left-eye sub-image strikes the left-eye diffuser 244 and creates a real image of the display on the diffuser surface. The left eyepiece compound optics 245 then magnifies this real image appropriately for left eye 146 .
The embodiment depicted in FIG. 2 is described using diffusers onto which real images are projected in order to prepare the image. Transition optics, having a small numerical aperture, project a real image onto the diffuser surface, and eyepiece optics having a large numerical aperture transport the image to the eyes of a user. Rather, any appropriate means may be used including microlens arrays, diffraction gratings, or other diffractive surfaces. For the purposes of the present invention, it will be understood that “diffuser” as used to describe the embodiments of the present invention, refers to all such means used to convert incident angular power density into an appropriate exiting angular power density.
In FIG. 2 , a right-eye sub-image follows the right-eye optical sub-path 130 into right eye transition optics 233 . The right eye transition optics 233 adjusts the right-eye display sub-image appropriately for reflection by right-eye reflector 132 onto right-eye diffuser 234 . The right-eye sub-image strikes right-eye diffuser 234 and creates a real image. This real image is adjusted by right eyepiece compound optics 235 appropriately for right eye 136 . Device 200 is capable of diopter correction through movement 253 of left-eye compound optics 245 and of movement 254 of right-eye compound optics 235 .
Device 200 is also capable of IPD adjustment through multiple synchronous movements. IPD 150 can be shortened by shifting left-eye compound optics 234 to the right with movement 251 , and right-eye compound optics 235 to the left with movement 252 . For the embodiment of FIG. 2 , segment 240 of optical sub-path 140 lies between transition optics 243 and diffuser 244 , and segment 230 of optical sub-path 130 lies between transition optics 233 and diffuser 234 . Thus, as compound optics 235 and 245 are shifted in movement 252 and 251 to shorten distance 150 , center section 201 should be shifted away from the facial plane 170 . The embodiment of FIG. 2 describes one combination of synchronous movements that result in IPD adjustment, but embodiments of the present invention are not limited to the synchronous movements of FIG. 2 .
FIG. 3 illustrates a prospective view of a head mounted device arranged according to an embodiment of the present invention. Head mounted device 300 includes section 101 , as described in relation to FIG. 1 , to split a display image of display 110 into a left-eye sub-image traveling along left-eye optical sub-path 140 and a right-eye sub-image traveling along right-eye optical sub-path 130 . In the embodiment depicted in FIG. 3 , a left-eye display sub-image follows left-eye optical sub-path 140 and passes through a left-eye real image reflector 342 to strike left-eye reflective diffuser 343 , thus creating a real image. This real image is then reflected by left-eye real image reflector 342 into left eyepiece optics 145 . Left eyepiece optics 145 adjusts a reflected real image appropriately for left-eye 146 . A right-eye display sub-image will follow right-eye optical sub-path 130 passing through right-eye real-image reflector 332 to strike right-eye reflective diffuser 333 , thus creating a real image. This real image is reflected by right-eye real-image reflector 332 into right eyepiece optics 135 which will adjust a reflected real-image appropriately for right-eye 136 .
The embodiment depicted in FIGS. 3A and 3B is described as using reflective diffusers on which real images are formed. The present invention is not limited to the use of any one type of diffuser. Rather, the embodiments may use any appropriate diffuser, as previously described, and may be any appropriate shape such as spherical, flat, or aspheric.
The embodiment in FIG. 3A is also capable of diopter correction through movement 153 of left eyepiece optics 145 and movement 154 of right eyepiece optics 135 . Left-eye real-image reflector 342 and left eyepiece optics 145 collectively make up left eyepiece 360 . Right-eye real-image reflector 332 and right eyepiece optics 135 collectively make up right eyepiece 361 .
Device 300 is capable of IPD adjustment through multiple simultaneous movements. The embodiment of FIG. 3 simultaneously moves left eyepiece 360 and right eyepiece 361 through movements 351 and 352 respectively to set the correct IPD. At the same time, movement 153 of left eyepiece optics 145 and movement 154 of right eyepiece optics 135 are moved to maintain the optical path lengths between eyepiece optics 145 , 135 and reflective diffusers 343 , 333 .
FIG. 3B illustrates the simultaneous movements one embodiment of the present invention utilizes to make the IPD adjustment described for FIG. 3A . As described above, IPD correction involves lateral movements 351 and 352 (of length d in FIG. 3A ) of eyepieces 360 and 361 . When such movements are made, however, the optical sub-paths 140 and 130 become longer. In order to maintain a constant length for optical sub-paths 140 and 130 , diffusers 343 and 333 are simultaneously perform lateral movements 371 and 372 (of length ½d in FIG. 3A ). In preferred embodiments, movement 351 is linked with movement 371 and movement 352 , but movements 352 and 351 are independent of each other.
FIGS. 3C and 3D illustrate one embodiment specific gear arrangements that can perform the linked movements described. The user adjusts IPD by sliding button 381 which is fixed directly to eye-piece 362 . As eyepiece 362 moves left and right, gear rack 382 drives idler gear 383 mated with ‘baseline’ rack 384 . Diffuser 333 (represented in the embodiment of FIGS. 3C and 3D as a mirror) is mounted onto idler gear 383 , which ensures that when the eyepiece 362 moves a certain distance, diffuser moves exactly half that distance. This linkage ensures that the optical sub-path 130 is a constant distance for all IPD values.
To allow for diopter correction, ‘baseline’ rack 384 is moved in direction 385 (towards optical axis 111 ), which in turn moves idler gear 383 and diffuser 333 towards beam splitter 120 (not shown), there by shortening optical sub-path 130 and moving the virtual image closer to the viewer. Rather than focusing the system, the virtual image is moved to the view where a user can see the image within their ‘diopter limits’. The mechanical of FIGS. 3C and 3D allows for a very flexible system that ensures that diffuser 333 is synchronized to eyepiece 362 and maintains a constant length for optical sub-path 362 for all IPD adjustments while maintaining any given ‘baseline’ diopter adjustment value. A similar system may be used for eyepiece 361 to ensure a constant length for optical sub-path 140 . Together, such systems provide independent left and right diopter correction.
In device 300 , left-eye real-image reflector 342 and right-eye real-image reflector 332 are partially reflective surfaces, but embodiments are not limited to the arrangement depicted. Rather, embodiments may easily be adapted to any arrangement, such as those using prisms, or polarizing beam splitters, that appropriately reflect light into eyepiece optics 135 and 145 and transmit light from optical paths 130 , 140 towards reflective diffusers 333 , 343 , respectively.
The embodiments of the present invention are not limited to arrangements that place an image splitter proximate to the focal point of a focusing optic. Rather, embodiments of the present invention are able to reduce the splitting volume of various applications, by positioning the image splitter to split a display image focused in a small area.
Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one will readily appreciate from the disclosure, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.
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A mechanism for adjusting an apparatus for the inter-pupilar distance of a user is disclosed. Example embodiments of the disclosed mechanism use gears that link the movements of eye-optics and reflectors placed along the optical path. When the eye-optics are adjusted, this movement causes a movement in the linked reflectors that maintains a constant length for the optical path.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a National Phase filing under 35 U.S.C. §371 of PCT/JP2007/062587 filed Jun. 22, 2007, which claims priority to Patent Application No. 2006-189732, filed in Japan on Jul. 10, 2006. The entire contents of each of the above-applications are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to cultivation of a cell or tissue in the fields of regeneration medicine and tissue engineering, and relates to a method of three dimensional tissue cultivation for a three dimensional tissue and or organ regeneration. Concretely, the above cultivating method is executed with any of a cell, a cell scaffold and an ECM (extracellular matrix) that a cell generates, as a cell construct. There may be a case where the above cultivating method is executed with addition of a culture fluid, other additives, a growth factor, a chemical and so on.
In short, the cultivating method of the present invention differs from the conventional static cultivation. The cultivating method of the present invention is a method relating to three dimensional cultivation where physical action is used together. The cultivating method is for realizing objective regeneration tissue by differentiation induction or dedifferentiation deterrence along with that growth, cell migration and substance migration are promoted to improve survivability of a cell by stimulating a cell of a cell construct aggressively and displacing a cell construct.
2. Description of the Related Art
For cultivation of a cell or tissue, a method of imparting physical stimulation such as pressure and tension to a cell or tissue to be cultivated is studied, and various bioreactors and so on are suggested. Two dimension cultivation (plane cultivation) is a cultivating method using a flat bottomed culture carrier, and in general, is a static cultivating method in an incubator. Suspension cultivation is a method of cultivating a non-adherent cell being suspended. This method is also a static cultivating method in an incubator. Three dimension cultivation is a method that is generally executed such that a cell scaffold where a cell is disseminated is left still in an incubator to be cultivated. It is general for the three dimension cultivation (using a bioreactor) that a cell is made to adhere to or is enclosed by a cell scaffold to process stirring of a culture fluid and so on. It is conceived that in the three dimension cultivation of a cell scaffold, physical action such as pressure, compression, tension and shear are imparted to a cell. A cultivation apparatus for imparting physical action is called “a bioreactor”, “a tissue engineering processor”, etc. This apparatus is being into practical utilization as a cell/tissue cultivation apparatus in vitro for cultivation experiments of tissue engineering and regeneration medicine.
Concerning such bioreactor having functions of cultivating a cell or tissue, and imparting physical displacement, stress and stimulation used in the cultivating, a method for cultivating a cell or tissue and an apparatus therefor are disclosed in Japanese Laid-open Patent Publication No. 2001-238663 (Abstract, etc.) as an example of using pressure and oscillation (supersonic wave), a method for in vivo, ex vivo and in vitro repair and regeneration of cartilage and collagen, and bone remodeling is disclosed in Published Japanese Translations of PCT International Publication for Patent Application No. 2004-512031 (Abstract, etc.) as an example of using pressure, a cell and tissue-cultivating apparatus is disclosed in Japanese Laid-open Patent Publication No. 2002-315566 (Abstract, etc.) as an example of using shear force, a cell and tissue-cultivating device is disclosed in Japanese Laid-open Patent Publication No. 2003-061642 (Abstract, etc.) as an example of using tensile force, a cell and tissue cultivation apparatus is disclosed in Japanese Laid-open Patent Publication No. 2003-180331 (Abstract, etc.) as an example of using compression force, a device for cultivating cell is disclosed in Japanese Laid-open Patent Publication No. H09-313166 (Abstract, etc.) as an example of using shear force, a loading device of extending and contracting stimulation for cultivating a cell by using a silicone belt is disclosed in Japanese Laid-open Patent Publication No. H10-155475 (Abstract, etc.) as an example of using tensile force, and an apparatus executing sterilization, inoculation, cultivation, preservation, transport and test of tissue and a synthetic or natural vascular graft, and a method therefor are disclosed in Published Japanese Translations of PCT International Publication for Patent Application No. H11-504216 (Abstract, etc.) as an example of using both tension and shear. A cultivating method where distortion is given to cells held on membranes by the membranes is disclosed in Japanese Laid-open Patent Publication No. 2005-143343 (Abstract, etc.). A semi-permeable membrane being used for cultivation is disclosed in International Publication Pamphlet No. WO 2006/015304 A2 (Abstract, etc.) and Published Japanese Translations of PCT International Publication for Patent Application No. 2000-513214 (Abstract, etc.). Imparting of various kinds of physical action and stimulation, and using of a semi-permeable membrane are tried for cultivation of a cell, etc.
There are regions receiving many kinds of stress in the human body. Tissue used for repairing these regions is different according to the regions. For example, a disc, a meniscus, a bone, fiber cartilage and a valve of a heart receive bending stress in vivo. This bending stress is different from simple pressure, compression, tension, shear, etc. It is unnecessary that tissue cultivated by stimulus factor such as a simple pressure, compression, tension and shear are applied to a region receiving such bending stress.
The inventors of the present invention conceives that bending is so useful for growth, etc. of a cell or tissue as stimulation or a load imparted to a cell or tissue to be cultivated. The present invention is based on such concept. Concerning this bending, there is no disclosure in the above patent documents and is no suggestion thereabout.
SUMMARY OF THE INVENTION
An object of the present invention relates to a method for cultivating a culture including a cell and/or tissue, and is to provide a method for cultivating a cell and/or tissue proper for a region of a body of a human being and so on.
To achieve the above object, the present invention relates to a method for cultivating a culture including a cell and/or tissue. By virtue of applying bending force to a culture including a cell and/or tissue to thereby bent the culture, concretely by virtue of curving the culture, continuous compression and extension in a direction of thickness from a concave portion toward a convex portion thereof are induced. The physical stimulation and deformation not attained by conventional pressurization, shear and tension, then can be loaded on the culture to thereby realize the culture appropriate for restoration of tissue at a region accompanied by bending.
To achieve the above object, a first aspect of the present invention there is provided a cultivating method of a culture including a cell and/or tissue, comprising loading bending motion to the culture.
To achieve the above object, preferably, in the above cultivating method, the bending motion may include a process that brings the culture into a curving state.
To achieve the above object, preferably, the above cultivating method may comprise disposing the culture on a bed able to be curved, wherein the bending motion may be executed by the medium of the bed.
To achieve the above object, preferably, in the above cultivating method, the bed at its both ends may be movably held, and the bed may be curved by imparting a load to a center part of the bed.
To achieve the above object, preferably, in the above cultivating method, the culture may be sealed by a semi-permeable membrane.
To achieve the above object, preferably, in the above cultivating method, the bending motion may be executed periodically or intermittently.
To achieve the above object, preferably, in the above cultivating method, the culture may include any of a cell, a cell scaffold, an extracellular matrix produced by the cell, and a culture fluid.
To achieve the above object, preferably, in the above cultivating method, the culture may be a three-dimensional culture scaffold where a cell is disseminated.
To achieve the above object, preferably, in the above cultivating method, the culture may include a gel substance.
To achieve the above object, preferably, in the above cultivating method, the three-dimensional culture scaffold may be a bioabsorbable material.
To achieve the above object, preferably, in the above cultivating method, the gel substance may be a bioabsorbable material.
To achieve the above object, preferably the above cultivating method may comprise any of imparting continuous tension to the culture; imparting intermittent tension to the culture; or imparting continuous or intermittent tension to the culture periodically.
To achieve the above object, preferably, the above cultivating method may comprise a process that pressures the culture, wherein pressure to the culture may be given continuously or intermittently, or may be changed periodically or irregularly.
Features and advantages of the present invention are as follows.
(1) Since displacement (stress) such as bending a culture is applied in cultivation, cultivation of a culture can be promoted. For example, culture can be used for regeneration of tissue receiving bending force in vivo like discs, etc.
(2) It can be expected to prevent a stem cell from differentiating and prevent a tissue cell from dedifferentiating.
(3) If tissue structure and so on have directionality, the direction thereof can be uniform, and a culture equal to tissue in vivo can be obtained.
(4) A necessary tissue can be cultivated by bending action without other kinds of physical action such as pressure, or with the minimum thereof.
(5) Cell migration can become easy.
(6) Nutrients and oxygen can be osmosed in the interior to a three dimensional cell construct.
(7) Discharging waste products becomes easy.
(8) If a semi-permeable membrane separates a part where a cell exists from a part of a culture fluid, shear force by flow of the culture fluid is excluded, and culture can be made with an action that is limited to bending and pressure.
(9) If a semi-permeable membrane separates a part where a cell exists from a part of a culture fluid, cells become a spheroid without a scaffold, and three dimensional tissue can be realized.
Other objects, features and advantages of the present invention are more clearly understood by referring to the attached drawings and each of the embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a structural example of a culture bed according to a first embodiment;
FIG. 2 is a flowchart showing processing procedure of cultivation;
FIG. 3 depicts a form of a cell construct to be cultivated;
FIG. 4A depicts a state that a cell construct is disposed on a culture bed;
FIG. 4B depicts a state that a cell construct is disposed on a culture bed;
FIG. 5A depicts imparting bending motion to a cell construct and cancellation thereof;
FIG. 5B depicts imparting bending motion to a cell construct and cancellation thereof;
FIG. 6A is a view relating to an analysis of force and displacement that a cell construct receives in a bending state;
FIG. 6B is a view relating to an analysis of force and displacement that a cell construct receives in a bending state;
FIG. 7A is an analysis diagram relating to displacement inside a gel column at a position in height;
FIG. 7B is an analysis diagram relating to displacement inside a gel column at a position in height;
FIG. 7C is an analysis diagram relating to displacement inside a gel column at a position in height;
FIG. 8A is an analysis diagram relating to displacement inside a gel column at a position in height;
FIG. 8B is an analysis diagram relating to displacement inside a gel column at a position in height;
FIG. 8C is an analysis diagram relating to displacement inside a gel column at a position in height;
FIG. 9A is an analysis diagram relating to displacement inside a gel column at a position in height;
FIG. 9B is an analysis diagram relating to displacement inside a gel column at a position in height;
FIG. 9C is an analysis diagram relating to displacement inside a gel column at a position in height;
FIG. 10 depicts a form of a cell construct according to a second embodiment;
FIG. 11 depicts a state that a cell construct is disposed on a culture bed;
FIG. 12 depicts a form of a cell construct according to a third embodiment;
FIG. 13 depicts a system for cultivating a cell or tissue according to a fourth embodiment;
FIG. 14 depicts an experimental example;
FIG. 15 depicts an experimental example;
FIG. 16 depicts an experimental example;
FIG. 17 depicts an experimental example; and
FIG. 18 depicts an experimental example.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
A method for cultivating a cell or tissue according a first embodiment of the present invention will be described.
A cell construct 2 ( FIG. 3 ) is used as an example of a culture in the method for cultivating cell or tissue. The cell construct 2 includes the any of a cell, a cell scaffold and an extracellular matrix that the cell generates. There may be a case where a culture fluid, other additives, a growth factor, a chemical and so on may be added. For example, the cell construct 2 may be structured by a culture fluid where cells are suspended, a complex of a three dimensional scaffold where cells are disseminated, and a gel substance or other scaffolds, and the culture fluid and the complex being enclosed in a bag or a tube made from a semi-permeable membrane. A three dimensional scaffold and a gel substance are composed of, for example, a bioabsorbable material.
The above semi-permeable membrane enclosing the cell construct 2 is made in accordance with a size of a molecule that can pass through the semi-permeable membrane. For instance, a semi-permeable membrane is selected out of semi-permeable membranes whose transmission molecular weight is from 100 (Da(Dalton)) to 1000 (kDa) to be used. That is, if a semi-permeable membrane such that substance of a low molecule like nutrition in a culture fluid, a necessary gas such as oxygen and waste matters exhausted by a cell exhausts pass to enclose cells and a polymeric extracellular matrix are not allowed to pass is selected, and a cell, nutrition and oxygen can be supplied while preventing an outflow of a cell and an extracellular matrix, and effective cultivation is realized.
A culture bed 4 is used for culture of the cell construct 2 . FIG. 1 depicts a structural example of this culture bed.
This culture bed 4 holds the cell construct 2 , and a means for imparting motion to the cell construct 2 . The culture bed 4 constitutes a function unit transmitting a displacement movement to the held cell construct 2 , and by elasticity that the culture bed 4 has, returning a state of the cell construct 2 to a state before the displacement movement.
A disposing part 6 where two cell constructs 2 can be disposed in parallel is included in the culture bed 4 . The disposing part 6 is a plate-shaped part having an area and a shape where each cell construct 2 is disposed in parallel, and made from an elastic member for imparting bending motion to each cell construct 2 . As an elastic member, for example a stainless steel sheet for a spring or other materials that have high spring are used. In this case, the whole culture bed 4 may be formed by an elastic member, or the disposing part 6 that enables bending motion or a part thereof may be formed by an elastic member. The deposing member 6 is not limited to a flat plate-shaped part, and may be net. The disposing part 6 may structure of deposing single cell construct 2 , or of allowing three or more cell constructs 2 to be disposed.
The disposing part 6 is a rectangular shape. At end parts in a longer direction thereof, rectangular standing walls 8 and 10 are formed. Each of the standing walls 8 and 10 is perpendicular to the disposing part 6 , and in the standing walls 8 and 10 , elliptic through holes 12 corresponding to each cell construct 2 are formed. These through holes 12 fix both ends of the cell construct 2 . Each of the standing walls 8 and 10 is set in a predetermined height h according to a size of each cell construct 2 .
At a top of each of the standing walls 8 and 10 , supporting faces 14 and 16 that face the disposing part 6 in parallel and have a constant width are formed. From each supporting face 14 and 16 , turnover 18 is formed in parallel to each of the standing walls 8 and 10 by turning a part of each supporting face 14 and 16 . Each turnover 18 reinforces each supporting face 14 and 16 , and each standing wall 8 and 10 . That is, sufficient strength can be obtained if each supporting face 14 and 16 , and each standing wall 8 and 10 are formed by the same board as the disposing part 6 which is made of a thin plate, and weight of the culture bed 4 can be saved. In the culture bed 4 of the embodiment, a U-formed notch 20 corresponding to a fixing pin not shown is formed in order to fix the supporting face 14 .
From middle edges of the disposing part 6 , supporting walls 22 and 24 that support sides of the disposed cell construct 2 are formed. From a top of each supporting wall 22 and 24 , holding parts 26 and 28 that cover a top surface of the cell construct 2 are formed. Each supporting wall 22 and 24 is a wall perpendicular to the disposing part 6 . The height thereof is the same as the above described standing walls 8 and 10 . Each holding part 26 and 28 constructs a parallel face with the disposing part 6 . The cell construct 2 is disposed in a gap between the disposing part 6 , and each holding part 26 and 28 . An end part of each holding part 26 and 28 constructs a curve face. Between the curve faces, a gap 30 for attaching and detaching the cell construct 2 is set.
A cultivating method of the cell construct 2 will be described with referring to FIGS. 2 , 3 , 4 A, 4 B, 5 A and 5 B. FIG. 2 is a flowchart showing processing procedure of cultivation, FIG. 3 depicts a form of a cell construct to be cultivated, FIGS. 4A and 4B depict disposing a cell construct on a culture bed and FIGS. 5A and 5B depict imparting bending motion to a cell construct and cancellation thereof.
As shown in FIG. 2 , a cultivation process of the cell construct 2 includes a preparation (step S 1 ), a cultivation process (step S 2 ) and a posttreatment (step S 3 ). The preparation includes forming the cell construct 2 , an enclosing process to a semi-permeable membrane, etc. The cultivation process includes a bending motion process. In the cultivation process, a curve process (step S 21 ), curve cancellation (step S 22 ), a curve process (step S 23 ) . . . curve cancellation (step S 2 N) are repeatedly executed. The posttreatment includes taking out of the cell construct 2 whose cultivation is ended from the culture bed 4 and so on.
(1) Preparation (step S 1 )
In forming of the cell construct 2 , tissue or a cell is taken out from in vivo, and the taken tissue is resolved by enzymes and so on to select a necessary cell. If the selected cell must be grown, a process of increasing the number of the cell may be executed in the preparation by monolayer culture and so on. The cell construct 2 is made from the obtained cell, and the combination of a culture fluid, a hydro-gel or a gel scaffold. As an infinite construct, a cell may be suspended in a culture fluid or a hydro-gel, or a cell may be mixed with a gel scaffold. As a finite construct, a cell may be suspended in a culture fluid, and the culture fluid is entered into a cell scaffold such as a collagen sponge and a chitosan sponge to be attached to the cell, or, a cell in a sol state is mixed into a scaffold, and the scaffold is entered in a cell scaffold such as collagen sponge and chitosan sponge to attach the cell and to gel the cell. A growth factor or chemist may be added if necessary.
As shown in FIG. 3 , the cell construct 2 of a culture is enclosed into a tube 32 that is made from a semi-permeable membrane to be cultivated. A stopper 34 made from, for example, a semi-permeable membrane is provided at one end of the tube 32 of a semi-permeable membrane. The above cell construct 2 is put into the tube 32 from another end thereof, and by shutting the another end by the stopper 34 as well, the cell construct 2 is sealed. The size of the tube 32 enclosing the cell construct 2 may change dependently on an object of a culture and a kind of the cell construct 2 , etc.
As shown in FIGS. 4A and 4B , the cell construct 2 sealed in the tube 32 is disposed on the disposing part 6 of the culture bed 4 . Concerning a disposing process to the culture bed 4 , the tube 32 enclosing the cell construct 2 is passed the gap 30 provided between the holding parts 26 and 28 , and both ends of the tube 32 is passed through the through holes 12 provided in each standing wall 8 and 10 . And the tube 32 is disposed such that a middle part thereof positions between the disposing part 6 and the holding part 26 or 28 . In the embodiment, two tubes 32 are disposed. The number thereof is not limited to the embodiment. Also, in the embodiment, both ends of the tube 32 are inserted into the through holes 12 to be fixed. The tube 32 may be held to the culture bed 4 by, for example, a clip for the tube, etc. in accordance with the size of a tube.
By disposing the tube like the above, each through part 12 and holding part 26 and 28 hold the tube 32 , for example, against curve of the culture bed 4 by force applied to the bottom side of the culture bed 4 and cancellation thereof, and the tube 32 is made to curve and is made restoration movement with the culture bed 4 to enable bending motion in a culture process described below.
(2) Culture process (step S 2 )
In the culture process, as shown in FIG. 5A , the cell construct 2 enclosed in the tube 32 is transferred to a culture chamber 36 that is a culture space with the culture bed 4 . A culture fluid 38 is supplied into the culture chamber 36 . After the cell construct 2 is set into the culture chamber 36 , the culture chamber 36 is made into a sealing state by, for example, a cover for preventing the culture fluid 38 , etc. from flowing out, and preventing contamination from an outside. The supporting faces 14 and 16 of the culture bed 4 disposed in the culture chamber 36 is held by the supporting member 40 . For the above, vertical difference does not occur to the culture bed 4 by applying following described force F from a back side, thus the culture bed 4 and the tube 32 can be curved. The culture chamber 36 may have a structure of maintaining its sealing state, and such that the culture fluid 38 is circulated to be supplied during the culture process. In this case, the culture fluid 38 may be continuously circulated in the culture chamber 36 , or may be periodically exchanged.
If the force F is loaded from the back side of the culture bed 4 by, for example, a lever not shown, as shown in FIG. 5B , the disposing part 6 of the culture bed 4 is curved upwardly by the force F. By this curve, the tube 32 on the disposing part 6 is also curved. That is, bending occurs to the cell construct 2 . If the force F is released from this bending state, the disposing part 6 of the culture bed 4 is restored to an original form by its elasticity to be flat. Thus, the cell construct 2 on the disposing part 6 switches into a flat state to be in a state shown in FIG. 5A again. In this case, on an upper face of the tube 32 , the holding parts 26 and 28 of the culture bed 4 exist. The tube 32 that is deformed to be upwardly convex is pressed onto the through holes 12 where both ends of the tube 32 are passed and the holding parts 26 and 28 in accordance with the restoration of the disposing part 6 to flatten dependently on the restoration of the disposing part 6 . As described above, the same amount of displacement as an amount of displacement of curve and flattening of the culture bed 4 is given to the cell construct 2 enclosed in the tube 32 by the through holes 12 and the holding parts 26 and 28 . Thus, by controlling an amount of movement by the adding force F, an amount of bending motion given to the cell construct 2 can be controlled, too.
Such bending motion is repeated (step S 21 -step S 2 N), a cell is propagated in the tube 32 as necessary culture time passes, and an extracellular matrix and so on are generated to regenerate infinite or finite neogenetic tissue. A period and magnitude of bending motion, a movement schedule, temperature setting in the culture chamber 36 , etc. are set by an optimum pattern and so on in advance of a start of the culture process. The settings may be optionally done in accordance with a cultivating state of a cell or tissue. If necessary, the structure may be made that pressure is applied into the culture chamber 36 to be cultivated.
Like the above, in case where the tube 32 of a semi-permeable membrane is used for cultivation, while shear stress generated between a culture fluid and a culture is prevented and flowing out of a cell and an extracellular matrix is prevented, nutrition and oxygen can be supplied and efficient culture is realized. However, because a semi-permeable membrane becomes resistance to passing nutrition, there is a risk that an obstacle to supplying nutrition occurs. As described above, by adding bending motion, inside displacement rises actively, difference of pressure occurs, nutrition is easily moved, and physical stimulation is imparted to a cell. For this, the cell construct 2 that a blood vessel is still not generated and tissue without a blood vessel can be cultivated with bending motion that acts for a blood vessel and a heart.
(3) Posttreatment (step S 3 )
The cell construct 2 whose culture is completed is taken out from the culture chamber 36 with the culture bed 4 ( FIG. 5A ). The tube 32 enclosing the cell construct 2 is taken out from the culture bed 4 , and neogenetic tissue such as cells propagating therein and a generated extracellular matrix are taken out. A quality inspection and so on are executed on the taken neogenetic tissue, and the neogenetic tissue is preserved till utilization for treatment of a human body and so on.
The cultivated neogenetic tissue is directly transplanted to a human body by means such as suture if finite tissue. If infinite tissue, the neogenetic tissue is processed such as injection into a deficit part, and application or forming to be fixed in response to a form of tissue. Then amalgamation with tissue therearound in vivo allows being organized.
Bending motion and cultivation in the cultivation process of the cell construct 2 will be described in FIGS. 6A and 6B . FIGS. 6A and 6B are a view used for an analysis of force and displacement that a column cell construct receives in a bending state.
The culture bed 4 is held at a predetermined position not to differ vertically, etc. in the culture chamber 36 as described above. The cell construct 2 is also fixed to the culture bed 4 . Thus, as shown in FIG. 5B , if the force F is applied from the back side of the culture bed 4 , the disposing part 6 of the culture bed 4 is curved upwardly, and the cell construct 2 deforms along the culture bed 4 .
If an object is to be bent, bending stress occurs. By bending an object, bending strain occurs. Many kinds of strain occur inside a bent object. That is, as shown in FIG. 6B , tensile force acts on an outer circumference side of bending (an upper side of FIG. 6B ), and the outer circumference side extends. Compression force acts on an inner circumference side thereof (a lower side of FIG. 6B ) vice versa, and the inner circumference side shrinks. Considering a micro part in an object, at a position where micro parts adjoin with each other, difference occurs to displacement of extension and shrink. Shearing stress occurs thereto. Thereby, shearing strain occurs. As shown by a heavy line in FIG. 6A , there is so-called a neutral plane where a part of an object has no displacement of extension and shrink ( 0 ). With including the neutral place, shearing strain occurs to all of positions. The shearing strain occurs in a regular direction.
A sectional area is changed by bending to change inside pressure. By changing a shape of a section, parts occur where pressure rises and falls inside an object. Since an outer circumference is tensed and an inner circumference is compressed, a part of the inner circumference is high pressure, and a part around the outer circumference is low pressure.
That is, tension, compression, shear and pressure act variously on bending. If bending motion is acted on the cell construct 2 , an inside of the cell construct 2 is slightly deformed by tension, compression, shear and pressure. Here, since a contraction percentage of a liquid by pressure is so particle that the contraction percentage can be ignored, strain by bending motion can cause huge strain much greater than strain caused by a method of repeatedly applying pressure to the cell construct 2 . From this, action of bending can bring effects such as movement and supply of a cell, nutrition, oxygen and waste matters more, and since shear force of tension and compression in a specific direction is generated for a bending direction, a formed tissue can be aligned uniformly.
Therefore, a cell appropriate for bending motion can be promoted to be propagated, and tissue whose alignment resembles to tissue in vivo can be cultivated. Along with bending, applying pressure can enlarge the effects.
As a model of the cell construct 2 , extension generated when a gel column bends, etc. will be analyzed with referring to FIGS. 6A and 6B .
As shown by oblique lines in FIG. 6A , FIG. 6B showing a section in a longitudinal direction of a gel column whose diameter before bending is d is considered. A lateral length before deformation is shown by L. A center line of the gel column is bent such that a curvature radius thereof becomes r. The height of the gel column before bending is d (diameter). The d is partitioned into m sections from inside to an outside of bending. The center line of the gel column is shown by 0 , and sections are numbered as −n toward an inside of the gel column, and as +n toward an outside thereof. In FIG. 6B , as one example, the gel column is divided into ten sections, and section positions from an inside one to an outside eleven of bending are shown by a contact point of each line dividing the gel column and a side face of the gel column being a calculation position of displacement.
Extension in a longitudinal direction is shown by ΔLn, displacement in a thick direction is shown by ΔRn and total displacement is shown by Dn. Displacement in a longitudinal direction (circumferential direction) by bending is analyzed. The gel column of length L shrinks at the inner circumference, and extends at the outer circumference. If the center line of the column before bending is a neutral plane, compression stress and tensile stress are equal. A curvature radius r n of the nth section is
( Formulae 1 ) r n = r + n m d ( 1 )
A chord length of the nth section is
( Formulae 2 ) L ⋒ n = L × r n r ( 2 )
Extension in a longitudinal direction ΔLn is
( Formulae 3 ) Δ Ln = L ⋒ n - L = L × r n r - L = L ( r n r - 1 ) ( 3 )
If formula (1) is substituted to formula (3),
(
Formulae
4
)
Δ
Ln
=
L
(
r
+
n
m
d
r
-
1
)
=
L
·
n
·
d
m
·
r
(
4
)
Displacement ΔRn in a thick direction (a direction of a curvature radius) is analyzed. If n sections from the most inside part when bending are bent, the sections that were a rectangle before displacement become a fan with retaining its area. When the gel column is bent, as described above, since a longitudinal direction changes, in response thereto, thickness thereof changes. With using this method, displacement in a thick direction is calculated. Distance r o from the center to the most inside face when bending is
( Formulae 5 ) r o = r - 1 2 d ( 5 )
An area of a rectangle from the most inside section to the nth section Sns is
( Formulae 6 ) S ns = n + m 2 m d · L ( 6 )
Area of a fan from the most inside section to the nth section Sn is
( Formulae 7 ) S n = L 2 π r ( π R n 2 - π r 0 2 ) ( 7 )
If Sns and Sn maintain the same areas (Sns=Sn), by formula (6) and formula (7),
( Formulae 8 ) ( n + m 2 m ) · d · L = L 2 π r ( π Rn 2 - π r 0 2 )
π Rn 2 - π r 0 2 = 2 π r · d · L ( n + m 2 ) Lm
π Rn 2 = 2 π r · d · L ( n + m 2 ) Lm + π r 0 2
R n 2 = 2 r · d ( n + m 2 ) m + r 0 2 ( 8 )
If formula (5) is substituted to formula (8),
(
Formulae
9
)
R
n
2
=
2
r
·
d
(
n
+
m
2
)
m
+
r
2
-
rd
+
d
2
4
=
2
rd
·
n
m
+
r
2
+
d
2
4
R
n
=
2
rd
-
n
m
+
r
2
+
d
2
4
(
9
)
As to the nth section before bending, distance r n from the center of a curvature is
( Formulae 10 ) r n = r + n m d ( 10 )
From this, displacement when bending ΔRn is
( Formulae 11 ) Δ Rn = R n - r n
Δ Rn = 2 r · d · n m + r 2 + d 2 4 - ( r + n m d ) ( 11 )
Therefore, total displacement Dn is calculated from (Formulae 12)
D n =√{square root over (Δ Ln 2 +ΔRn 2 )} (12)
With using the above analysis, displacement inside the gel column is shown in FIGS. 7A , 7 B, 7 C, 8 A, 8 B, 8 C, 9 A, 9 B and 9 C. FIGS. 7A , 7 B and 7 C are analysis diagrams relating to displacement inside a gel column at a center position in height ten (=diameter d, the number of section=10), FIGS. 8A , 8 B and 8 C are analysis diagrams relating to displacement inside a gel column at a position in height eight (the number of section=8)(a position differing from the center) and FIGS. 9A , 9 B and 9 C are analysis diagrams relating to displacement inside a gel column at a position in height four (the number of section=4) (a position further differing from the center).
In detail, a change when the gel column of ten in diameter (d=10) is bent at a curvature radius 50 (r=50) is analyzed. The column is divided into ten sections vertically and horizontally respectively. Displacement of length thereof is shown by a value for ten (L=10). Graphs show the cases where the height is ten (a section dividing the center of a circle, FIG. 7A ), the height is eight ( FIG. 8A ), and the height is four ( FIG. 9A ) when the gel column is seen from a circular face side of the column. A section position representative of a calculated position of displacement is shown in a horizontal axis, total displacement (Dn), displacement in a thick direction (ΔRn) and extension in a longitudinal direction (ΔLn) are shown in a vertical axis, and an amount of displacement is shown in height.
From the above analyzed result, it is determined that if the column is bent, difference in size and a direction of displacement is inevitable between a point on a circle section of the column and an adjacent point thereto. By the difference, shear stress occurs to every part of the column. Note that to points on a line in a longitudinal direction, the equivalent displacement and stress occur.
Second Embodiment
A method of cultivating a cell or tissue according to a second embodiment of the present invention will be described with referring to FIGS. 10 and 11 . FIG. 10 depicts a form of a cell construct 2 according to a second embodiment, and FIG. 11 depicts a state that the cell construct 2 is disposed on a culture bed 4 . In FIGS. 10 and 11 , the same parts and the same components as those of the first embodiment are denoted by the same reference numerals.
In this embodiment, in the cultivating method according to the first embodiment, the infinite cell construct 2 is enclosed into a tube 42 of a semi-permeable membrane to be cultivated. For example, concerning the infinite cell construct 2 that a cell is suspended in a culture fluid or a hydro-gel, or that a cell is mixed with a gel scaffold, by tube 42 of a semi-permeable membrane not being a frame, infinite tissue is kept after cultivation, thus, tissue according to use such as insertion between tissue in vivo can be cultivated. The above gel substance is, for example, constructed of a bioabsorbable material.
Such cell construct 2 ( FIG. 10 ) can be also cultivated by using the above described cultivating method ( FIG. 2 ). In this case, in preparation, because of using the high flexible tube 42 , a shape of an opening section is infinite. For sealing of both openings of the tube 42 , flexibility that the tube 42 has is utilized, and in stead of the stopper 34 ( FIG. 3 ), both openings thereof are sealed by clips 44 dedicated for the tube 42 . That is, for preventing the cell construct 2 from flowing out of the tube 42 , both ends of the tube 42 are turned down, and a process is executed such that overlapped parts are sealed by the clips 44 . In order to prevent burst of the tube 42 by bending motion and make a space for moving the cell construct 2 in the tube 42 , etc. a proper amount of the cell construct 2 is needed to be enclosed into the tube 42 not to be in a full state. The amount thereof depends on an objected amount of cultivation. For example, the cell construct 2 is enclosed so that a section of the tube 42 of a semi-permeable membrane becomes a shape of an ellipse.
The cell construct 2 enclosed in the tube 42 as described above is attached to the culture bed 4 as shown in FIG. 11 . Concerning a disposing process to the culture bed 4 as well as the first embodiment, the tube 42 enclosing the cell construct 2 is passed the gap 30 provided between the holding parts 26 and 28 , and both ends of the tube 42 are passed through the through holes 12 provided in each standing wall 8 and 10 . And the tube 42 is disposed such that a middle part thereof positions between the disposing part 6 and the holding part 26 or 28 . By disposing like this, bending motion to the cell construct 2 can be imparted in accordance with curve of the disposing part 6 of the culture bed 4 and cancellation thereof by bending motion in the above cultivation process.
In such structure, a cultivation process as well as that in the first embodiment allows cultivation of the infinite cell construct 2 as described above.
Concerning fixing the cell construct 2 and the culture bed 4 , the structures may be done that for example, the clip 44 sandwiches the tube 42 and the culture bed 4 together, and that a clip for fixing the culture bed 4 is provided with the clip 44 together, other than the above structure.
Third Embodiment
A method of cultivating a cell or tissue according to a third embodiment of the present invention will be described with referring to FIG. 12 . FIG. 12 depicts a form of a cell construct according to a third embodiment. In FIG. 12 , the same parts and the same components as those of the first embodiment are denoted by the same reference numerals.
In the embodiment, concerning the cultivating method according to the first embodiment, a cell is disseminated on a finite cell scaffold (three-dimensional scaffold) 48 and the finite cell construct 2 is made, then the finite cell construct 2 is enclosed into the tube 32 of a semi-permeable membrane to be cultivated. Concretely, a cell may be suspended in a culture fluid or a hydro-gel, or a cell may be mixed with a gel scaffold. As a finite construct, a cell may be suspended in a culture fluid, and the culture fluid is entered into a cell scaffold such as a collagen sponge and a chitosan sponge to be attached to the cell, or, a cell in a sol state is mixed into a scaffold, and the scaffold is entered in a cell scaffold such as collagen sponge and chitosan sponge to attach the cell and to gel the cell. A three dimensional scaffold and a gel substance are constructed of, for example, a bioabsorbable material. A cultivating method is the same as that in the above first embodiment, and the description thereof is omitted.
By the above structure, using the finite cell construct 2 in advance allows cultivation of neogenetic tissue that has a desired shape or size.
Fourth Embodiment
A cultivation system for a cell or tissue according to a fourth embodiment of the present invention will be described with referring to FIG. 13 . FIG. 13 depicts a system for cultivating a cell or tissue. In FIG. 13 , the same parts and the same components as those in the first embodiment are denoted by the same reference numerals, and descriptions thereof are omitted.
In the embodiment, in the method for cultivating a cell or tissue according to the first to the third embodiments, a culture system 50 is structured that a culture fluid is circulated, a fresh culture fluid is supplied at any time and temperature and pressure in a culture room, and concentration of a supplied mixed gas G, etc. are controlled to cultivate a cell or tissue.
In the culture system 50 , an incubator 52 that is a culture apparatus is used. In a culture room 53 of the incubator 52 , a culture unit 54 , a culture circuit 56 , and actuator 58 , a temperature adjustor 60 , a gas concentration adjustor 62 and a pressure apparatus 64 are provided. These are controlled by a controller 66 that is outside the incubator 52 .
The culture unit 54 is a culture means for cultivating by imparting pressure and the previous described force F, etc. to the cell construct 2 . Inside the culture unit 54 , the culture chamber 36 that is the above described culture space is formed. The pressure apparatus 64 is controlled by the controller 66 , and acts pressure P on a bottom face side of the culture bed 4 in the culture chamber 36 .
The culture circuit 56 is a means for supplying and circulating the culture fluid 38 , etc. to the culture means. The culture circuit 56 is constructed of a culture fluid tank 70 that stores the culture fluid 38 , a gas exchanger 72 that supplies the mixed gas G (nitrogen, oxygen, carbon dioxide, etc.) to the culture fluid 38 and the culture room 53 , a pump 74 , a check valve 76 and a circulation tube 80 that connects the culture unit 54 to a pressure adjusting valve 78 adjusting pressure in the culture room 53 and the culture chamber 36 .
For the pump 74 , for example, a piston pump, a syringe pump and a peristaltic pump can be used. Drive of the pump 74 , open and close of the pressure adjusting valve 78 , a degree of open thereof, etc, are adjusted by the controller 66 . The actuator 58 is a driving source for the culture unit 54 that imparts the force F to the cell construct 2 . The temperature adjustor 60 adjusts temperature in the culture room 53 and the culture chamber 36 . The gas concentration adjustor 62 adjusts concentration of the mixed gas G (nitrogen, oxygen, carbon dioxide, etc.) supplied to the culture fluid tank 70 and the culture fluid 38 . The controller 66 controls each of the above function units. Concretely, the controller 60 may control all of temperature adjustment and gas concentration adjustment, etc., and may control circulation of the culture fluid tank 70 , movement of the pump 74 , movement of the actuator 58 , etc.
By executing the above described cultivation process with such culture system 50 , a cultivation process of loading bending motion can be executed, and the culture circuit 56 allows to supply the culture fluid 38 into the culture chamber 36 and exclude waste matters, etc. The pressure apparatus 64 can control pressure to the culture unit 54 continuously, intermittently or periodically, and cultivate a cell or tissue while temperature and pressure remains in a desired state. As a result, efficient and reliable cultivation can be executed.
In this culture system 50 , the culture fluid tank 70 , the actuator 58 and the pump 74 are provided inside the incubator 52 . The culture system 50 is not limited to the above structure. All or a part thereof them may be structured outside the incubator 52 . Concerning movement of the actuator 58 , pressure to the culture chamber 36 in the pressure apparatus 64 and movement of the pump 74 supplying the culture fluid 38 , etc. may be linked. If the cultivation process intermits in the middle thereof and bending motion is loaded periodically or intermittently, effective stimulation can be imparted to a cell.
Other Embodiment
In the above embodiments, to the cell construct 2 that is a culture, the force F is imparted from the back side of the culture bed 4 , and by curving the culture bed 4 upwardly, the cell construct 2 is bent. A predetermined bending displacement may be imparted to the culture bed 4 or the cell construct 2 itself. In this process, the predetermined bending displacement may be imparted continuously or intermittently, or continuous or intermittent tension may be imparted periodically. In such structure, a predetermined vending can be also given to the cell construct 2 .
Result of Experiment
A result of an experiment using the cultivating method of the present invention will be described with referring to FIGS. 14 and 18 .
FIG. 14 shows a cell construct. This cell construct is structured such that a cell suspended in a culture fluid is entered in a tube of a semi-permeable membrane. As shown in FIG. 15 , the cell construct is fixed to a culture bed, and is accommodated in a culture chamber. In this case, a driving unit is separated from the culture chamber.
Pressure from an actuator acted on a culture unit, and bending motion is imparted to the cell construct. The actuator is disposed outside a culture room. A cable is penetrated through a door of the culture chamber to be connected to the driving unit. A movement state of the actuator could be confirmed by a display.
The actuator converts a rotating movement of a motor to straight line movement by a crank. By selection of the length of a crank arm, back and forth width of a wire could be adjusted, and in accordance with this, a size of bending imparted to the cell construct could be adjusted.
In this experiment, pressure movement is limited to bending motion, atmospheric pressure is maintained and the culture fluid is circulated. Pressure and bending motion by the actuator are imparted individually, irrelevantly and solely. In the experiment, for example, it can be considered that pressure equal to or over 0.5 (MPa) is imparted.
FIGS. 16 to 18 show an experiment of vertebrae organ culture of a two days old mouse. In the experiment, a vertebra taken out from the two days old mouse is disposed on the culture bed ( FIG. 16 ) and bending motion of 0.1 (Hz) frequencies is imparted to be cultivated for ten days. In this experiment, no pressure is applied.
As a comparison example, static cultivation is executed. FIGS. 17 and 18 show static cultivation for ten days. After ten days, a section of an organ is toluidine blue-stained, and condition of a cell existing is observed. In FIGS., a stained part can not be expressed. A part where brightness falls down (showing a stained part) shows existence of a living cell. In the static cultivation, cell density inside discs does not rise, and displacement of matrixes can be seen (a of FIG. 17 ).
On the contrary, in vertebrae where bending motion and displacement are imparted, growth of cells and store of neogenetic matrixes can be seen inside discs. (b of FIG. 18 ).
From the result of the experiment, in the cultivation of imparting bending motion, growth of cells and store of neogenetic matrixes could be seen as compared with the static cultivation. Thus, it can be guessed that bending motion thereof gives stimulation to the cell construct, and substance migration is promoted.
While the present invention has been described with the preferred embodiments, the description is not intended to limit the present invention. Various modifications of the embodiments based on the subject matters and objects described in claims or disclosed in this specification will be apparent to those skilled in the techniques, and such modifications rightfully fall within the true scope of the present invention.
The present invention relates to a method for cultivating of a cell or tissue. Stimulation by bending motion is given to a cell construct, and substance migration in neogenetic tissue without a blood vessel is promoted to promote propagation of cells, and cultivation in a state where tissue in vivo is imitated can be executed. So, the present invention is useful.
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A method for cultivating a culture of a cell, tissue, etc. There is provided a method of cultivating a culture including a cell or tissue (cell construct), imparting bending motion to the culture. By virtue of applying bending force to a culture of a cell, tissue, etc. (cell construct) to thereby curve the culture, continuous compression and extension in a direction of thickness from a concave portion toward a convex portion thereof are induced. The physical stimulation and deformation not attained by conventional pressurization, shear and tension, then can be loaded on the culture to thereby realize the culture appropriate for restoration of tissue at a region accompanied by bending.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Divisional Application of prior U.S. patent application Ser. No. 11/699,987 filed Jan. 31, 2007, which is a Continuation of prior U.S. patent application Ser. No. 11/029,487 filed Jan. 6, 2005, which is a Continuation Application of prior U.S. patent application Ser. No. 09/406,844 filed on Sep. 29, 1999, which claims priority under 35 U.S.C. §119 to Korean Application No. 41481/1998 filed on Oct. 1, 1998, whose entire disclosure is hereby incorporated by reference.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present invention relates in general to mobile communication terminals, and more particularly to a method for branching data in a mobile communication terminal.
[0004] 2. Description of the Prior Art
[0005] Until now, a conventional mobile communication system has provided only a pure speech service or a simple short message service (referred to hereinafter as SMS). With a third-generation mobile communication system being developed, there have recently been proposed a multimedia service and short/long packet services.
[0006] Such third-generation services require a new layer, which is called a media access control (referred to hereinafter as MAC) sublayer.
[0007] The MAC sublayer has to perform a branching operation suitable to a service characteristic in order to appropriately process a variety of services.
[0008] However, the conventional mobile communication system is disadvantageous in that the MAC sublayer cannot efficiently branch various multimedia and packet services because the system provides only simple services such as the SMS.
SUMMARY OF THE INVENTION
[0009] Therefore, the present invention has been made in view of the above problem, and it is an object of the present invention to provide a method for branching data in a mobile communication terminal, in which a media access control sublayer attaches logical channel types based on traffic characteristic identifiers from a radio resource control layer and other upper layers to a media access control header and performs mapping and multiplexing/demultiplexing between logical channels and transport channels according to the attached logical channel types to branch the data.
[0010] In accordance with one aspect of the present invention, in a method for performing data communication between a mobile station and a network which have media access control sublayers, respectively, there is provided a method for branching data in a mobile communication terminal, comprising the first step of allowing each of the media access control sublayers of the mobile station and network to attach logical channel types based on traffic characteristic information and a radio bearer status to a media access control header contained in data to be sent, in a data sending mode; the second step of allowing each of the media access control sublayers to branch the data to be sent, to transport channels corresponding to the attached logical channel types; the third step of allowing each of the media access control sublayers to determine logical channels corresponding to logical channel types of a media access control header contained in received data in a data receiving mode; and the fourth step of allowing each of the media access control sublayers to branch the received data to the determined logical channels.
[0011] Preferably, each of the second and fourth steps may include the step of allowing each of the media access control sublayers to perform a channel mapping operation in a one-to-one manner, a channel multiplexing operation in a many-to-one manner and a channel demultiplexing operation in a one-to-many manner to branch the data to be sent or the received data.
[0012] Further, preferably, the traffic characteristic information may include traffic characteristic identifiers transferred from a radio resource control layer and other upper layers.
[0013] Further, preferably, each of the traffic characteristic identifiers may represent any one of random access data, synchronization data, system information, paging information, forward access grant information, short message service data, no radio bearer-type short packet data, signaling data, radio bearer-type short/long packet data, multicast signaling data, multicast data and speech characteristics.
[0014] In accordance with another aspect of the present invention, in a method for performing data communication between a mobile station and a network which have media access control sublayers, respectively, there is provided a method for branching data in a mobile communication terminal, comprising the first step of allowing each of said media access control sublayers of said mobile station and network to set information regarding connection between logical channels and transport channels on the basis of traffic characteristic information and a radio bearer status; the second step of allowing each of said media access control sublayers to attach logical channel types based on the set connection information to a media access control header contained in data to be sent, in a data sending mode; and the third step of allowing each of said media access control sublayers to branch said data to be sent, to transport channels corresponding to the attached logical channel types.
[0015] In a feature of the present invention, a media access control sublayer attaches logical channel types based on traffic characteristic identifiers from a radio resource control layer and other upper layers to a media access control header and performs mapping and multiplexing/demultiplexing between logical channels and transport channels according to the attached logical channel types to branch data. This makes it possible to efficiently provide various multimedia and packet services.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
[0017] FIGS. 1 a and 1 b are views illustrating data branched states between mobile and base stations to which a method for branching data in a mobile communication terminal in accordance with the present invention is applied.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] FIGS. 1 a and 1 b are views illustrating data branched states between mobile and base stations to which a method for branching data in a mobile communication terminal in accordance with the present invention is applied.
[0019] A method for branching data in a mobile communication terminal in accordance with the present invention will hereinafter be described in detail with reference to FIGS. 1 a and 1 b.
[0020] As shown in FIGS. 1 a and 1 b , channels associated with a MAC sublayer are classified into logical channels and transport channels.
[0021] The logical channels are mapped into MAC-service access points (referred to hereinafter as SAPs) in interfaces between the MAC sublayer and upper layers, respectively.
[0022] The above logical channels may generally be classified into a synchronization control channel (referred to hereinafter as SCCH) for transferring system synchronization data in simplex through a downlink, a broadcast control channel (referred to hereinafter as BCCH) for broadcasting system information in simplex through the downlink, a paging control channel (referred to hereinafter as PCCH) for transferring paging information in simplex through the downlink, a common control channel (referred to hereinafter as CCCH) for transferring random access data, forward access control data and short packet data in duplex through the downlink and an uplink, a dedicated control channel (referred to hereinafter as DCCH) for transferring dedicated signal control information in duplex through the downlink and uplink, and a dedicated traffic channel (referred to hereinafter as DTCH) for transferring dedicated user long/short packet data in duplex through the downlink and uplink.
[0023] The CCCH, DCCH and DTCH are adapted to transfer some data on the basis of the connection between the MAC sublayer and a radio resource control (referred to hereinafter as RRC) layer and the presence of a radio bearer. Namely, the CCCH transfers random access data under the condition that the RRC layer is not connected to the MAC sublayer, and the DCCH transfers SMS data, signaling data and a multicast signal under the condition that the RRC layer is connected to the MAC sublayer. The DTCH transfers short/multicast packet data under the condition that no radio bearer is present and short/long/multicast packet data under the condition that a radio bearer is present.
[0024] The above multicast signal, short/multicast packet data and short/long/multicast packet data are available only on a network.
[0025] The transport channels are mapped into physical (referred to hereinafter as PHY)-SAPs in interfaces between the MAC sublayer and PHY layers, respectively.
[0026] The above transport channels may generally be classified into a synchronization channel (referred to hereinafter as SCH) including first and second channels for transferring a system synchronization signal, a broadcast channel (referred to hereinafter as BCH) for broadcasting system information in simplex through the downlink, a paging channel (referred to hereinafter as PCH) for transferring paging information in simplex through the downlink, a forward access channel (referred to hereinafter as FACH) for transferring forward access grant information and short packet data in simplex through the downlink, a random access channel (referred to hereinafter as RACH) for transferring random access data and short packet data in simplex through the uplink, a downlink shared channel (referred to hereinafter as DSCH) for multicasting user data in simplex through the downlink, and a dedicated channel (referred to hereinafter as DCH) for transferring dedicated signal information and dedicated user data in duplex through the downlink and uplink.
[0027] On the other hand, in a sending entity, the MAC sublayer has to create a MAC protocol data unit (PDU) with a MAC header including a type of a logical channel through which upper layer data is to be transferred. In a receiving entity, the MAC sublayer utilizes the logical channel type of the MAC header to determine a logical channel into which the received MAC PDU is to be demultiplexed. This procedure will hereinafter be described in detail while being classified into channel mapping and channel multiplexing/demultiplexing between a mobile station and a network.
[0028] First, a description will be given of a channel mapping operation for data sending and reception between the mobile station and network.
[0029] The channel mapping operation is performed in the mobile station in the following manner.
[0030] In the case where the mobile station is to send data to the network, the MAC sublayer of the mobile station maps the CCCH which is a logical channel for transferring random access data, to the RACH which is a transport channel, in a one-to-one manner.
[0031] In the case where the mobile station is to receive data from the network, the MAC sublayer of the mobile station maps the SCH which is a transport channel for transferring signaling data, the BCH which is a transport channel for transferring system information and the PCH which is a transport channel for transferring paging information, respectively, to the SCCH, BCCH and PCCH which are logical channels, in the one-to-one manner.
[0032] The channel mapping operation is performed in the network in the following manner.
[0033] In the case where the network is to send data to the mobile station, the MAC sublayer of the network maps the SCCH which is a logical channel for transferring system synchronization data, the BCCH which is a logical channel for transferring system information, the PCCH which is a logical channel for transferring paging information and the CCCH which is a logical channel for transferring forward access grant information, respectively, to the SCH, BCH, PCH and FACH which are transport channels, in the one-to-one manner.
[0034] Noticeably, the channel mapping operation is not performed in the network with respect to data which is sent from the mobile station to the network.
[0035] Next, a description will be given of channel multiplexing/demultiplexing operations of the mobile station.
[0036] The channel multiplexing operation of the mobile station is performed in the following manner.
[0037] First, the RRC layer and other upper layers of the mobile station transfer traffic characteristic identifiers to the MAC sublayer of the mobile station.
[0038] The MAC sublayer of the mobile station attaches logical channel types based on traffic characteristics of the traffic characteristic identifiers from the RRC layer and other upper layers to a MAC header. Then, the MAC sublayer branches data to transport channels corresponding to the attached logical channel types through PHY-SAPs.
[0039] The traffic characteristics may generally be random access data, synchronization data, system information, paging information, forward access grant information, SMS data, short packet data (no radio bearer), signaling data, short/long packet data (radio bearer), multicast signaling data, multicast data and speech characteristics.
[0040] For example, if the random access data, SMS data and no radio bearer-type short packet data characteristics are required, the MAC sublayer of the mobile station attaches types of the CCCH, DCCH and DTCH to the MAC header and multiplexes the CCCH, DCCH and DTCH to the RACH in a many-to-one manner to branch data through PHY-SAPs. Here, the CCCH is a logical channel for transferring random access data, the DCCH is a logical channel for transferring SMS data, the DTCH is a logical channel for transferring no radio bearer-type short packet data, and the RACH is a transport channel.
[0041] In the case where the signaling data and radio bearer-type short/long packet data characteristics are required, the MAC sublayer of the mobile station attaches types of the DCCH and DTCH to the MAC header and multiplexes the DCCH and DTCH to the DCH in the many-to-one manner to branch data through PHY-SAPs. Here, the DCCH is a logical channel for transferring signaling data, the DTCH is a logical channel for transferring radio bearer-type short/long packet data, and the DCH is a transport channel.
[0042] The channel demultiplexing operation of the mobile station is performed in the following manner.
[0043] The network, or sending entity, attaches logical channel types based on traffic characteristics to a MAC header and the mobile station, or receiving entity, performs the channel demultiplexing operation on the basis of the logical channel types attached to the MAC header.
[0044] For example, if a transport channel through which data from the network, or sending entity, is sent is the FACH, the MAC sublayer of the mobile station demultiplexes the FACH to logical channels corresponding to traffic characteristics of logical channel types attached to a MAC header of the sent data in a one-to-many manner to branch the sent data to upper layers through MAC-SAPs.
[0045] That is, for example, in the case where the forward access grant information, SMS data and no radio bearer-type short packet data characteristics are required by the sending entity, the MAC sublayer of the mobile station recognizes that logical channel types attached to a MAC header of received data correspond respectively to the CCCH, DCCH and DTCH and demultiplexes the FACH to the CCCH, DCCH and DTCH in the one-to-many manner to branch the received data to upper layers through MAC-SAPs. Here, the FACH is a transport channel, and the CCCH, DCCH and DTCH are logical channels.
[0046] If the multicast signaling data and multicast data characteristics are required by the sending entity, the MAC sublayer of the mobile station recognizes that logical channel types attached to a MAC header of received data correspond respectively to the DCCH and DTCH and demultiplexes the DSCH to the DCCH and DTCH in the one-to-many manner to branch the received data to upper layers through MAC-SAPs. Here, the DSCH is a transport channel, and the DCCH and DTCH are logical channels.
[0047] In the case where the dedicated signaling data and radio bearer-type short/long packet data characteristics are required by the sending entity, the MAC sublayer of the mobile station recognizes that logical channel types attached to a MAC header of received data correspond respectively to the DCCH and DTCH and demultiplexes the DCH to the DCCH and DTCH in the one-to-many manner to branch the received data to upper layers through MAC-SAPs. Here, the DCH is a transport channel, and the DCCH and DTCH are logical channels.
[0048] Finally, a description will be given of channel multiplexing/demultiplexing operations of the network.
[0049] The channel multiplexing operation of the network is performed in the following manner.
[0050] First, the RRC layer and other upper layers of the network transfer traffic characteristic identifiers to the MAC sublayer of the network.
[0051] The MAC sublayer of the network attaches logical channel types based on traffic characteristics of the traffic characteristic identifiers from the RRC layer and other upper layers to a MAC header. Then, the MAC sublayer branches data to transport channels corresponding to the attached logical channel types.
[0052] The traffic characteristics may generally be random access data, synchronization data, system information, paging information, forward access grant information, SMS data, short packet data (no radio bearer), signaling data, short/long packet data (radio bearer), multicast signaling data, multicast data and speech characteristics.
[0053] For example, in the case where the forward access grant information, SMS data and no radio bearer-type short packet data characteristics are required, the MAC sublayer of the network attaches types of the CCCH, DCCH and DTCH to the MAC header and multiplexes the CCCH, DCCH and DTCH to the FACH in the many-to-one manner to branch data through PHY-SAPs. Here, the CCCH is a logical channel for transferring forward access grant information, the DCCH is a logical channel for transferring SMS data, the DTCH is a logical channel for transferring no radio bearer-type short packet data, and the FACH is a transport channel.
[0054] If the multicast signaling data and multicast data characteristics are required, the MAC sublayer of the network attaches types of the DCCH and DTCH to the MAC header and multiplexes the DCCH and DTCH to the DSCH in the many-to-one manner to branch data through PHY-SAPs. Here, the DCCH is a logical channel for transferring multicast signaling data, the DTCH is a logical channel for transferring multicast data, and the DSCH is a transport channel.
[0055] In the case where the signaling data and radio bearer-type short/long packet data characteristics are required, the MAC sublayer of the network attaches types of the DCCH and DTCH to the MAC header and multiplexes the DCCH and DTCH to the DCH in the many-to-one manner to branch data through PHY-SAPs. Here, the DCCH is a logical channel for transferring signaling data, the DTCH is a logical channel for transferring radio bearer-type short/long packet data, and the DCH is a transport channel.
[0056] The channel demultiplexing operation of the network is performed in the following manner.
[0057] The mobile station, or sending entity, attaches logical channel types based on traffic characteristics to a MAC header and the network, or receiving entity, performs the channel demultiplexing operation on the basis of the logical channel types attached to the MAC header.
[0058] For example, in the case where a transport channel through which data from the mobile station, or sending entity, is sent is the RACH, the MAC sublayer of the network demultiplexes the RACH to logical channels corresponding to traffic characteristics of logical channel types attached to a MAC header of the sent data in the one-to-many manner to branch the sent data to upper layers through MAC-SAPs.
[0059] Namely, for example, if the forward access grant information, SMS data and no radio bearer-type short packet data characteristics are required by the sending entity, the MAC sublayer of the network recognizes that logical channel types attached to a MAC header of received data correspond respectively to the CCCH, DCCH and DTCH and demultiplexes the RACH to the CCCH, DCCH and DTCH in the one-to-many manner to branch the received data to upper layers through MAC-SAPs. Here, the RACH is a transport channel, and the CCCH, DCCH and DTCH are logical channels.
[0060] In the case where the dedicated signaling data and radio bearer-type short/long packet data characteristics are required by the sending entity, the MAC sublayer of the network recognizes that logical channel types attached to a MAC header of received data correspond respectively to the DCCH and DTCH and demultiplexes the DCH to the DCCH and DTCH in the one-to-many manner to branch the received data to upper layers through MAC-SAPs. Here, the DCH is a transport channel, and the DCCH and DTCH are logical channels.
[0061] As apparent from the above description, according to the present invention, the MAC sublayer performs mapping and multiplexing/demultiplexing between logical channels and transport channels according to traffic characteristics to branch data. Therefore, the present invention has the effect of efficiently providing various multimedia and packet services.
[0062] Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.
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A method for branching data in a mobile communication terminal to perform data communication between a mobile station and a network which have media access control sublayers. In a data sending mode, each of the media access control sublayers of the mobile station and network attaches logical channel types based on traffic characteristic information and a radio bearer status to a media access control header contained in data to be sent. Then, each of the media access control sublayers branches the data to be sent, to transport channels corresponding to the attached logical channel types. In a data receiving mode, each of the media access control sublayers determines logical channels corresponding to logical channel types of a media access control header contained in received data. Then, each of the media access control sublayers branches the received data to the determined logical channels. Each of the media access control sublayers performs mapping and multiplexing/demultiplexing between logical channels and transport channels according to traffic characteristics to branch data. Therefore, it is possible to efficiently provide various multimedia and packet services.
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This is a division of application Ser. No. 157,181, filed Jan. 27, 1988, now U.S. Pat. No. 4,816,579 which is a division of application Ser. No. 52,296, filed May 21, 1987, now U.S. Pat. No. 4,743,697, which is a division of application Ser. No. 870,564, filed June 4, 1986, now U.S. Pat. No. 4,687,865.
BRIEF DESCRIPTION OF THE INVENTION
The present invention relates to a method for making 7-oxabicycloheptane aminoalcohol intermediates of the structure ##STR7## which compounds are novel compounds and are useful in preparing thromboxane A 2 receptor antagonists such as of the structure ##STR8## as disclosed in U.S. application Ser. No. 750,948, filed July 1, 1985 now abandoned, and which are useful in inhibiting platelet aggregation and thus in the treatment of thrombotic disease and inhibiting bronchoconstriction associated with asthma.
The method of the invention includes the steps of reacting meso-anhydride B ##STR9## with an optically active amine of the structure C ##STR10## wherein R is alkyl, CH 2 OH, CO 2 H or CO 2 alkyl, to form the acid II ##STR11## which is a novel compound.
Acid II is then reduced by treatment with lithium aluminum hydride or diisobutyl aluminum hydride or sodium bis(2-methoxyethoxy)aluminum hydride (Red-al) to form the alcohol III ##STR12## wherein R 1 is CH 2 OH when R is CO 2 H, CO 2 alkyl or CH 2 OH, and R 1 is alkyl when R is alkyl, which are novel compounds.
Where in the formula III compound R 1 is CH 2 OH, that is, ##STR13## compound IIIA is treated with an alkylchloroformate D
D ClCO.sub.2 alkyl
and a base to form IIIA' ##STR14## IIIA' is then dissolved in an alcohol solvent and treated with an alkali metal alkoxide base to form the alcohol IV ##STR15## (which is a novel compound) which then is subjected to a cleavage reaction by treating IV with alkali metal, liquid ammonia and after ammonia is allowed to evaporate off, and treating with an acid to form the acid salt of the alcohol amine I or IB depending on the configuration of the starting optically active amine C. The acid salt portion may be removed by simply treating the acid salt of compound I with a base such as sodium hydroxide.
Where in the formula III compound R 1 is alkyl, that is ##STR16## (which is a novel compound) compound IA or IB is prepared from IIIB by simply hydrogenating IIIB in the presence of a hydrogenation catalyst such as palladium on charcoal.
DETAILED DESCRIPTION OF THE INVENTION
The term "lower alkyl" or "alkyl" as employed herein alone or as part of another group contains 1 to 12 carbons and preferably 1 to 7 carbons in the normal chain and includes both straight and branched chain carbons, such as methyl, ethyl, propyl, isopropyl, butyl, t-butyl, isobutyl, pentyl, hexyl, isohexyl, heptyl, 4,4-dimethylpentyl, octyl, 2,2,4-trimethylphenyl, nonyl, decyl, undecyl, dodecyl, the various branched chain isomers thereof, and the like as well as such groups including a halo-substituent, such as F, Br, Cl or I or CF 3 , an alkyl-aryl substituent, a haloaryl substituent, a cycloalkyl substituent, an alkylcycloalkyl substituent, hydroxy, an alkanoylamino substituent, an arylcarbonylamino substituent, a nitro substituent, a cyano substituent or a thiol substituent.
In carrying out the process of the invention, the reaction of mesoanhydride B with optically active amine C is carried out in the presence of an inert organic solvent such as tetrahydrofuran, methylene chloride, ether, chloroform, benzene, toluene or mixtures thereof at a temperature within the range of from about -30° to about 50° C., preferably from about 0° C. to room temperature. The mesoanhydride B is employed in a molar ratio to amine C of within the range of from about 1:1 to about 0.5:1.
The acid II formed will actually comprise a mixture of acids IIA and IIB ##STR17## Where the (D) isomer of amine C is employed as the starting reactant, the mixture of IIA and IIB will be formed of about 85 parts IIB and 15 parts IIA. However, where the (L) isomer of amine C is employed, the mixture of IIA and IIB will be formed of about 85 parts IIA and 15 parts IIB.
The D and L isomers, IIA and IIB, respectively, may be separated from each other by conventional crystallization techniques.
Thereafter, the so-formed acid II is reduced with lithium aluminum hydride or diisobutyl aluminum hydride or sodium bis(2-methoxyethoxy)aluminum hydroxide (Red-Al) in the presence of an inert organic solvent such as tetrahydrofuran, toluene or mixtures thereof at a temperature within the range of from about 0° C. to reflux temperature and preferably from about 0° to about 80° C.
Compound III, R 1 is CH 2 OH, that is alcohol IIIA, is reacted with alkylchloroformate D in a molar ratio of IIIA:D of within the range of from about 2:1 to about 0.5:1 and preferably from about 1.5:1 to about 1:1 in the presence of a base such as potassium carbonate (to maintain pH of the reaction mixture at within the range of from about 7 to about 12 and preferably from about 8 to about 10), at a temperature within the range of from about 0° to about room temperature (about 25° C.). The product obtained is dissolved in an alcohol and treated with sodium methoxide or potassium methoxide to form alcohol IV. The alcohol IV so formed is then treated with lithium, sodium or potassium in the presence of liquid ammonia, and after removing NH 3 , treated with acid such as hydrochloric acid to form the amino alcohol intermediate IA or IB which will be in the form of acid salt in water solution.
To isolate IA or IB from solution, the solution is treated with base, such as NaOH, KOH or LiOH and a protecting agent is added, such as chloride E or ##STR18##
E Q--Cl wherein Q is a protecting group such as ##STR19## or any other standard protecting group, employing a molar ratio of IA or IB:E of within the range of from about 2:1 to about 0.5:1 to form the protected compound E ##STR20## which precipitates from solution or is removed by conventional solvent extraction. The protecting group Z is then removed (when Z is a benzyloxy carbonyl group) by hydrogenating F in the presence of palladium on charcoal or platinum dioxide catalyst in the presence of ethanol or methanol.
Where in compound III, R 1 is alkyl, that is alcohol IIIB, IIIB is hydrogenated in the presence of palladium on carbon catalyst or platinum dioxide catalyst to form aminoalcohol IA or IB.
It will be understood that where the starting optically active amine C is in the D form, the amino-alcohol I obtained will be in the D form, that is IA, ##STR21## Where the starting optically active amine C is in the L form, the amino-alcohol I obtained will be in the L form, that is IB, ##STR22##
The compounds of structure IA, IB, II, III, IIIA, IIIA', IIIB and IV are novel intermediate compounds and as such can be depicted by the following general formula: ##STR23## wherein A and B are different so that when one of A and B is ##STR24## the other is CO 2 H; when one of A and B is ##STR25## (wherein R 1 is CH 2 OH or alkyl), the other is CH 2 OH; when one of A and B is ##STR26## or ##STR27## the other is CH 2 OH; and when one of A and B is ##STR28## the other is CH 2 OH.
The alcohol IV and the amino alcohol IA or IB may then be employed to prepare thromboxane A 2 receptor antagonists in accordance with the following reaction sequences. ##STR29##
The nucleus in each of the 7-oxabicycloheptane compounds prepared in accordance with the method of the invention is depicted as ##STR30## for matter of convenience; it will also be appreciated that the nucleus in the compounds of the invention may be depicted as ##STR31##
The intermediate compounds IA and IB prepared in accordance with the method of this invention are useful in preparing amides of the structure A. Amides A are cardiovascular agents useful as platelet aggregation inhibitors, such as in inhibiting arachidonic acid-induced platelet aggregation, e.g., for treatment of thrombotic disease such as coronary or cerebral thromboses, and in inhibiting bronchoconstriction. They are also selective thromboxane A 2 receptor antagonists and synthetase inhibitors, e.g., having a vasodilatory effect for treatment of myocardial ischemic disease, such as angina pectoris.
The amide compounds A may also be used in combination with a cyclic AMP phosphodiesterase (PDE) inhibitor such as theophylline or papaverine in the preparation and storage of platelet concentrates.
The amide compounds A can be administered orally or parenterally to various mammalian species known to be subject to such maladies, e.g., humans, cats, dogs, and the like in an effective amount within the dosage range of about 1 to 100 mg/kg, preferably about 1 to 50 mg/kg and especially about 2 to 25 mg/kg on a regimen in single or 2 to 4 divided daily doses.
The active substance can be utilized in a composition such as tablet, capsule, solution or suspension containing about 5 to about 500 mg per unit of dosage of a compound or mixture of compounds of formula I. They may be compounded in conventional matter with a physiologically acceptable vehicle or carrier, excipient, binder, preservative, stabilizer, flavor, etc. as called for by accepted pharmaceutical practice. Also as indicated in the discussion above, certain members additionally serve as intermediates for other members of the group.
The amide compounds A may also be administered topically to treat peripheral vascular diseases and as such may be formulated as a cream or ointment.
The following Examples represent preferred embodiments of the present invention. Unless otherwise indicated, all temperatures are expressed in degrees Centigrade.
EXAMPLE 1
[1S-[1α,2β,3β(S*),4α]]-3-[[[2-(1,1-Dimethylethoxy)-2-oxo-1-phenylethyl]amino[carbonyl]-7-oxabicyclo[2.2.1]heptane-2-carboxylic acid (D-isomer)
A solution of meso-anhydride B (16.23 gm, 0.096 moles) in tetrahydrofuran (THF) (50 ml) was added to a stirring solution of D-phenylglycine-t-butyl ester in THF (200 ml) in one portion at ice bath temperature. The reaction mixture was stirred for 2 hours at room temperature. The THF was removed on a rotovap; the residue was redissolved in EtOAc and washed with 10% aqueous HCl acid (200 ml). The title compound was crystallized from pure EtOAc in 65% (23.6 gm) yield as a single pure isomer, m.p. 141°-142° C., [α] D =-91.1 (c=1, CHCl 3 ), m.p. of the corresponding mono methyl ester is 156°-157° C.; [α] D =-109.6° (c=1, CHCl 3 ).
Anal Calcd for C 21 O 6 NH 27 : C, 64.77; H, 6.99; N, 3.59 Found: C, 64.91; H, 6.97; N, 3.56
EXAMPLE 2
[1R-[1α,2β,3β(S*),4α]]-3-[[[2-(1,1-dimethylethoxy)-2-oxo-1-phenylethyl]amino]carbonyl]-7-oxabicyclo[2.2.1]heptane-2-carboxylic acid (L-isomer)
Following the procedure of Example 1 except using L-phenylglycine-t-butyl ester in place of the corresponding D-analogue, the title compound was isolated in 65% crystallized yield as a single isomer, m.p. 142°-145° C. [α] D =+95.5.
EXAMPLE 3
[1S-[1α,2β,3β(S*),4α]]-3-[[(2-Hydroxy-1-phenylethyl)amino]methyl]-7-oxabicyclo[2.2.1]heptane-2-methanol
A solution of Example 1 acid (8 gm, 0.02 mole) in tetrahydrofuran (THF) (50 ml) was added dropwise to a stirring suspension of LAH (lithium aluminum hydride) (4.8 gm, 0.127 mole) in THF (200 ml) at ice bath temperature. After the addition, the ice bath was removed and the reaction mixture was refluxed for 20 hours. Saturated Na 2 SO 4 solution was added dropwise to the reaction mixture at ice bath temperature until the grey suspension becomes a white granular precipitate. The suspension was refluxed for 10 minutes and filtered. The filtrate was dried for 1 hour over anhydrous sodium sulphate and the solvent was removed on a rotavap to obtain 3.7 gm of title alcohol as a thick glass (64%) single spot, R f =0.3 (18:1:1, CH 2 Cl 2 :HOAc:MeOH; silica gel).
Anal Calcd for the corresponding oxalic acid salt: C, 58.84; H, 6.85; N, 3.8 Found: C, 58.41; H, 6.80; N, 3.88
EXAMPLE 4
[1S-[1α,2β,3β(S*),4α]]-3-[[(2-Hydroxy-1-phenylethyl)amino]methyl]-7-oxabicyclo[2.2.1]heptane-2-methanol
To a solution of Example 1 acid (10.0 gm, 0.0257 mole) in THF (100 ml) at ice bath temperature was added sodium bis(2-methoxyethoxy)aluminum hydride (Red-Al) (45 ml, 0.154 mole) and after the addition, the reaction mixture was refluxed for 16 hours. A saturated Na-K-tartrate solution was added to the ice-cold reaction mixture with vigorous stirring to form a homogeneous reaction solution. It was diluted with water and extracted with ethyl acetate to get 8.2 gm of oil material. The residue is dissolved in 10 ml methanol and treated with 2.3 gm of oxalic acid in 10 ml methanol. After 1 hour the crystals were filtered to get 5.0 gm of the title oxalic acid salt.
EXAMPLE 5
[1R-[1α,2β,3β(S*),4α]]-3-[[(2-Hydroxy-1-phenylethyl)amino]methyl]-7-oxabicyclo[2.2.1]heptane-2-methanol
Following the procedure of Examples 3 and 4, except substituting the Example 2 acid for the Example 1 acid, the title L isomer is obtained.
EXAMPLE 6
[1S-[1α,2β,3β(S*),4α]]-3-[[(Ethoxycarbonyl)(2-hydroxy-1-phenylethyl)amino]methyl]-7-oxabicyclo[2.2.1]heptane-2-methanol
To the solution of Example 3 alcohol (1.01 gm, 0.00361 mole) in THF (20 ml) was added potassium carbonate (0.5 gm) and water (5 ml) and the mixture was cooled to 5° C. Ethyl chloroformate (0.6 ml) was added to the reaction mixture with stirring while keeping the temperature at about 5° C. and maintaining the pH at about 10.0. After maintaining the pH at ˜10.0 for 2 hours, TLC indicated complete reaction. Usual extractive work-up using ethyl acetate produced quantitative yield of title compound (1.27 gm, 100%). Rf=0.6 (18:1:1, CH 2 Cl 2 ; HOAc:MeOH).
EXAMPLE 7
[1S-[1α,2β,3β(S*),4α]]-3-[(2-Oxo-4-phenyl-3-oxazolidinyl)methyl]-7-oxabicyclo[2.2.1]heptane-2-methanol
The Example 6 compound was dissolved in methanol (10 ml) and treated with 1 ml methanolic sodium methoxide solution (0.0036 mole). After stirring for 2 hours at room temperature, usual extractive workup produced 1.05 gm of title compound (95%), m.p. 131°-133° C. [α] D =-49.0° (c=1, CHCl 3 ).
Anal Calcd for C 17 H 21 NO 4 : C, 67.31; H, 6.98; N, 4.62 Found: C, 67.10; H, 6.97; N, 4.54
EXAMPLE 8
[1S-[1α,2β,3β,4α]]-3-(Aminomethyl)-7-oxabicyclo[2.2.1]heptane-2-methanol
To a solution of Li (0.4 gm, 0.057 mole) in liquid ammonia (200 ml) at -78° C. was added a solution of Example 7 compound (0.7 gm, 0.0023 mole) in THF (25 ml). The reaction mixture was stirred for 30 minutes and 3 ml t-butanol was added to it and the stirring continued for 20 minutes. TLC showed absence of starting material. The reaction mixture was quenched with 5 gm of NH 4 Cl and the ammonia was allowed to evaporate overnight at room temperature. The residue obtained was acidified with 20% HCl acid and extracted using ethyl acetate (2×100 ml) and the organic layer discarded. The aqueous phase was basified to pH 9.0 using 20% NaOH solution. 5 Ml of Z-Cl (benzyloxy carbonyl chloride) was added keeping the temperature between 5°-10° C. and maintaining the pH ˜8. After the pH stabilized, the reaction was stopped and extracted using ethyl acetate (3×200 ml). After usual extractive workup, 5 gms of solid material was produced which was dissolved in 100 ml ethyl acetate and diluted with 100 ml methanol and hydrogenated over 18% Pd(OH) 2 on carbon (1.0 gm). After 1 hour, the catalyst was filtered and the solvent removed on a rotavap to give an oily residue (0.5 gm). This residue was dissolved in 5 ml water and extracted with ethyl acetate (2×20 ml) and the ethyl acetate layer discarded. The aqueous layer was evaporated on a rotavap to give a clear oil, 0.4 gm, 96% of the title amino alcohol as the free base. TLC: single spot, Rf=0.3 (1:1:1:1; MeOH:HOAc:EtOAc:CH 3 CN) 0.2 gm of the material was dissolved in 2 ml methanol and treated with 1 ml of ethereal HCl acid. Solvent evaporation followed by crystallization produced the title amino alcohol hydrochloride, 0.22 gm (89%) yield, m.p. 145°-148° C., [α] D =-14.9°; [α] 365 =-42.8° (c=1, MeOH).
EXAMPLE 9
[1R-[1α,2β,3β,4α]]-3-(Aminomethyl)-7-oxabicyclo[2.2.1]heptane-2-methanol
Following the procedures of Examples 6, 7 and 8, except substituting the Example 5 alcohol for the Example 3 alcohol, the title compound is obtained.
EXAMPLE 10
[1S-[1α,2β,3β(S*),4α]]-3-[[(1-Phenylethyl)amino]carbonyl]-7-oxabicyclo[2.2.1]heptane-2-carboxylic acid
Following the procedure as outlined in Example 1, except using D-phenethylamine for D-phenylglycine-t-butyl ester, the title compound is obtained; yield after crystallization was 23%, m.p. 141°-142° C. [α] D =+75.6° (c=1, MeOH).
EXAMPLE 11
[1R-[1α,2β,3β(S*),4α]]-3-[[(1-Phenylethyl)amino]carbonyl]-7-oxabicyclo[2.2.1]heptane-2-carboxylic acid
Following the procedure as outlined in Example 2 except using L-phenethylamine in place of L-phenylglycine-t-butyl ester, the title compound is obtained; yield after crystallization was 23%, [α] d =-73.5° (c=1, MeOH).
EXAMPLE 12
[1S-[1α,2β,3β(S*),4α]]-3-[[(2-Hydroxy-1-phenylethyl)amino]carbonyl]-7-oxabicyclo[2.2.1]heptane-2-carboxylic acid
Following the procedure of Example 1 except substituting D-phenylglycinol for D-phenylglycine-t-butyl ester, a mixure of the above title compounds is obtained.
Following the procedures as outlined in the previous examples employing the Examples 10, 11 or 12 acid in place of the Example 1 acid, the amino alcohol compounds of the invention are obtained.
EXAMPLE 13
[1S-[1α,2β(5Z),3β,4α]]-7-[3-[[[[(1-Oxoheptyl)amino]acetyl]amino]methyl]-7-oxabicyclo[2.2.1]hept-2-yl]-5-heptenoic acid
A. [1S-[1α,2β,3β(S*),4α]]-3-[(2-oxo-4-phenyl-3-oxazolidinyl)methyl]-7-oxabicyclo[2.2.1]heptane-2-methanol, p-toluenesulfonate ester
To a solution of 30.0 gms of the Example 7 alcohol (0.099 mole) in pyridine at 0° C. is added 21.0 (0.11 mole) gms of p-toluene sulfonylchloride. After the addition, the cooling bath is removed, the reaction mixture is stirred at room temperature for 24 hours and then poured into crushed ice. The usual extractive workup produces the title tosylate.
B. [1S-[1α,2β,3β(S*),4α]]-7-[3-[(2-oxo-4-phenyl-3-oxazolidinyl)methyl]-7-oxabicyclo[2.2.1]hept-2-yl]-5-heptynoic acid
5-Hexyne-1-carboxylic acid 0.96 gm (0.01 mole) is dissolved in 10 ml THF and cooled to -78° C. n-Butyllithium (0.2 mole) is added slowly with vigorous stirring to the acetylene solution and the mixture stirred for 5 minutes at -78° C.; this solution is transferred to the Part A tosylate compound (4.6 gm, 0.01 mole) in THF (20 ml) at -78° C. with vigorous stirring. After stirring the reaction for 1 hour at -78° C., it is allowed to warm up to room temperature and by that time the reaction is complete by TLC monitoring. Acidification followed by usual extractive workup produces title compound.
C. [1S-[1α,2β,3β(S*),4α]]-7-[3-[(2-oxo-4-phenyl-3-oxazolidinyl)methyl]-7-oxabicyclo[2.2.1]hept-2-yl]-5-heptenoic acid
3.8 gms (0.01 moles) of the Part B acetylene compound is dissolved in 25 ml methanol and 2 ml pyridine is added to it. 0.5 gms of 5% Pd on BaSO 4 is added to it and the mixture stirred under an atmosphere of H 2 gas till the starting material disappears as observed by TLC analysis (˜1 to 2 hours). The catalyst is filtered and the solvents are removed on a rotavap to produce the title cis-olefin compound in quantitative yield.
D. [1S-[1α,2β,3β(Z),4α]]-7-[3-(aminomethyl)-7-oxabicyclo[2.2.1]hept-2-yl]-5-heptenoic acid
To the solution of lithium (0.4 gm, 0.057 mole) in liquid ammonia (200 ml) at -78° C. is added a solution of the Part C olefin (3.8 gm, 0.0078 mole) in THF (25 ml). The reaction mixture is stirred for 30 minutes and 3 ml t-butanol is added to it and the stirring continued for 20 minutes. TLC shows absence of starting material. The reaction mixture is quenched with 5 gm of NH 4 Cl and the ammonia is allowed to evaporate overnight at room temperature. The residue obtained is acidified to pH 7.0 using 20% HCl acid and extracted using chloroform solvent followed by usual workup to produce the title amino acid.
E. [1S-[1α,2β(5Z),3β,4α]]-7-[3-[[[[(1-Oxoheptyl)amino]acetyl]amino]methyl]-7-oxabicyclo[2.2.1]hept-2-yl]-5-heptenoic acid
To a suspension of Part D amino acid (3.4 gm, 0.0182 mole) in chloroform (60 ml) is added solid carbonyldiimidazole (2.95 gm, 0.01818 mole) with stirring and ice cooling. The resulting mixture is stirred for 2 hours at room temperature. Part D amine compound (4.4 gm, 0.017 mole) is added as a solid to the carbonyldiimidazole reaction mixture and the entire mixture is stirred at room temperature for 20 hours. Usual extractive workup followed by crystallization from ethyl acetate produces the title product.
EXAMPLE 14
[1S-[1α,2β(5Z),3β,4α]]-7-[3-[[[[(1-Oxoheptyl)amino]acetyl]amino]methyl]-7-oxabicyclo[2.2.1]-hept-2-yl]-5-heptenoic acid
A. [1S-[1α,2β,3β,4α]]-3-[[[(Phenylmethoxy)carbonyl](phenylmethyl)amino]-7-oxabicyclo[2.2.1]heptane-2-methanol
To a solution of 1.6 gm (0.01 mole) of Example 8 amino alcohol in 20 ml chloroform is added triethylamine (1.1 gm, 0.011 mole) followed by benzylbromide (1.7 gm, 0.01 mole). The mixture is refluxed for 10 hours where upon TLC indicates the absence of any starting material. The residue obtained on removal of the solvent is dissolved in 10 ml THF and 10 ml water and 1.4 gms of potassium carbonate is added to it and the mixture cooled in an ice bath to 0°-5° C. Benzyloxycarbonyl chloride (Z-Cl), (2 gm, 0.011 mole) is added to it and the mixture stirred at 0°-5° C. for 2 hours. It is diluted with water and extracted with ethyl acetate. The crude material obtained on evaporation of the solvent is chromatographed using silica gel and ethyl-acetate hexane solvent (1:1) system to produce title compound.
B. [1S-[1α,2β,3β,4α]]-3-[[[(Phenylmethoxy)carbonyl](phenylmethyl)amino]-7-oxabicyclo[2.2.1]heptane-2-methanol, p-toluenesulfonate ester
Following the procedure outlined in Example 13, Part A, the title tosylate is obtained. 3.8 gm (0.01 mole) of the alcohol produces 4.5 gm of the title tosylate.
C. [1S-[1α,2β,3β,4α]]-3-[[[(Phenylmethoxy)carbonyl](phenylmethyl)amino]-7-oxabicyclo[2.2.1]heptynoic acid
Following the procedure as outlined in Example 13, Part B, 5.35 gm (0.01 mole) of Part B tosylate produces 4.0 gm of the title acetylenic acid.
D. [1S-[1α,2β,3β(Z),4α]]-3-[[[(Phenylmethoxy)carbonyl](phenylmethyl)amino]-7-oxabicyclo[2.2.1]heptenoic acid
Following the procedure as outlined in Example 13 Part C, 4.7 gm (0.01 mole) of Part B acetylene compound gives 4.7 gm of the title cis-olefin.
E. [1S-[1α,2β,3β(Z),4α]]-7-[3-(aminomethyl)-7-oxabicyclo[2.2.1]hept-2-yl]-5-heptenoic acid
Following the procedure as outlined in Example 13 Part D, 4.7 gm (0.01 mole) of the Part D acid after lithium ammonia reduction produces 2.0 gm (80%) of the title amino acid.
F. [1S-[1α,2β(5Z),3β,4α]]-7-[3-[[[[(1-Oxoheptyl)amino]acetyl]amino]methyl]-7-oxabicyclo[2.2.1]hept-2-yl]-5-heptenoic acid
Following the procedure of Example 13 Part E, except substituting the Example 14 Part E compound for the Example 13 Part D compound, the title product is obtained.
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A process is provided for preparing a 7-oxabicycloheptane amino alcohol intermediate of the general structure ##STR1## which is useful in preparing thromboxane A 2 receptor antagonists. This intermediate is prepared by reacting mesoanhydride with an aryl amine ##STR2## wherein R is alkyl, CH 2 OH, CO 2 H or CO 2 alkyl, to form the acid ##STR3## which is reduced by treatment with lithium aluminum hydride or diisobutylaluminum hydride or Red-Al to form the alcohol ##STR4## wherein R 1 is CH 2 OH when R is CO 2 H, CO 2 alkyl or CH 2 OH, and R 1 is alkyl when R is alkyl; where in the above alcohol R 1 is CH 2 OH, such alcohol compound is treated with an alkyl chloroformate in the presence of base such as an alkali metal alkoxide to form the alcohol ##STR5## which undergoes cleavage by treatment with alkali metal, ammonia and acid to form the amino alcohol intermediate.
Where in the above alcohol R 1 is alkyl, that is ##STR6## such alcohol may be hydrogenated to form the aminoalcohol intermediate. All of the above 7-oxabicycloheptane compounds are novel and also form part of the present invention.
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BACKGROUND OF THE INVENTION
The present invention relates to a machine with a centrifugal drum for centrifuging the liquid from a wet material and with a stripper for removing the residue from the centrifugal drum. A machine of this kind for preparing coffee extract is described in DE-OS No. 26 26 330. It comprises an extremely complicated gear mechanism for driving the centrifugal drum at different speeds, whereby the axle of the centrifugal drum is provided on one side of the principal driving axle of the machine. The centrifugal drum with its vertical axle is in parts continuously closed and in parts continuously open at the bottom which creates unfavourable working conditions. The machine is principally conceived for continuous working. As a result rapid and complete short time ejection of the coffee grounds after each boiling of individual portions is not possible.
It is also known to construct the centrifugal drum by means of two shells which may be axially shifted together and relative to each other. In a first axial position of the centrifugal drum, one may centrifuge the liquid from the wet material, more particularly by boiling of coffee. In a second axial position of the centrifugal drum, the same is opened by the relative axial displacement of both shells of the drum for radially centrifuging of the coffee grounds. A clean, complete removing of the coffee grounds in this case is practically not possible (DE-OS No. 26 16 296).
It is further known to mount in the centrifugal drum an axially slideable bottom which may be shifted axially for axially ejecting the residue, e.g. coffee grounds in a coffee machine (CH-PS No. 600 847). In this case, it is also difficult to achieve always a nice and rapid cleaning and to provide desirable working reliability.
SUMMARY OF THE INVENTION
A general object of the invention is to considerably simplify and improve the construction and the mode of working of a machine having a stripper of the kind described above. This object is achieved by providing a centrifugal drum that is closed at one front side by a lift off cover. The stripper and the centrifugal drum are driven at the same number of revolutions for centrifuging the liquid. The number of revolutions of the centrifugal drum may be reduced with respect to the number of revolutions of the stripper so that the axially extracting action of the rotating stripper ejects unavoidably the residue when the cover is lifted off. This construction permits an extremely rapid and complete cleaning due to the fact that when the centrifugal drum is slowed down with the stripper rotating at its full number of revolutions, the residue is suddenly and nearly completely removed through the end of the centrifugal drum which is exposed by the lifted cover. However, during the centrifugal procedure, the striper is ineffective because its number of revolutions coincide with the number of the centrifugal drum and the centrifugal drum is closed on both sides, so that any loss of liquid is avoided. The centrifugal drum may be optimally designed for processing a material, e.g. coffee to be extracted. It can be executed with a short axial length with respect to its diameter thereby providing a relatively small filtering surface, and because it is closed during the centrifugation, a material to be extracted like coffee powder and the extracting liquid may be brought together with any optimal distribution on the whole surface of the filter.
The centrifugal drum may be driven in a simple manner by means of, for example, a sliding clutch, a friction clutch, magnetic clutch or the like and the braking down of the centrifugal drum may occur by a simple mechanical brake. In this way, expensive, complicated and space consuming gear mechanisms are completely avoided because the machine according to the invention comprises substantially only parts which are secured to a single driving shaft and parts which are driven by this shaft through a sliding clutch. The actuation of the cover of the centrifugal drum is achieved by a simple mechanism dependent on the number of revolutions, whereby the closing of the cover may be achieved by centrifugal force and the opening of the cover by a spring force or by gravity.
The invention will be described further by way of an example of a coffee machine illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, aspects, uses and advantages of the present invention will be more fully appreciated as the same become better understood from the following detailed description of the present invention when considered in connection with the accompanying drawings, in which:
FIG. 1 shows an axial section through the machine; and
FIG. 2 shows a partial section through the centrifugal drum.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The housing of the machine illustrated in FIGS. 1 and 2 comprises a bottom 1, a jacket in two parts 2a, 2b and a cover 3, these parts being firmly and tightly connected with each other. A driving motor, preferably an asynchrounous induction motor from which only the upper bearing 4 and the upwards projecting shaft 5 are shown, is provided under the bottom 1 of the housing. A hub 6 is screwed on the shaft 5. A fan disc 7 is screwed on the lower front side of the hub 6. The fan disc 7 bears fan blades 8, e.g. in form of two pins diametrically arranged and facing each other. The fan is thus still rigidly driven by the motor. On a shoulder of the hub 6 is placed the internal ring of a ball bearing on the external ring 9 of which a plate 10 is mounted. Thus, the plate 10 may rotate freely on the hub 6. Balls 12 are placed loosely in a circular groove 11 of the plate 10. Under the action of centrifugal force, the balls 12 may act against a downward curved annular surface 13 of a cover 14, the hub 15 of which is rotatably mounted on the hub 6 and supported by the inner ring of the corresponding ball bearing. The cover 14 comprises at its upper side a flat joint ring 16. The cover may thus rotate and be shifted axially on the hub 6. Under the action of the centrifugal force of the balls 12, the cover can be lifted from the illustrated initial position.
The plate 10 is connected by means of screws 17 and spacers 18 with a centrifugal drum 19, the jacket of which is provided with slits 20 thus acting as a filter. The upper flange 21 of the centrifugal drum 19 is engaged tightly into a groove between an upper rim 22 of a coffee mill and a ring 23 supported by the coffee mill. The centrifugal drum may thus freely rotate with the plate 10. The upper rim 22 of the coffee mill with its conical milling indentation 24 is supported by a threaded tube 25. The lower rim 26 of the coffee mill which comprises a corresponding conical indentation threadably engages the hub 6 and is consequently rigidly driven by the motor. By twisting of the threaded tube 25, the axial position of the non rotatable upper rim 22 of the coffee mill can be precisely adjusted, thus determining the fineness of the milled coffee. In the hole of the threaded tube 25 are radial bores 28 which communicate with an external circular space 29 in which opens a feeding pipe for hot boiling water. This water may be delivered by a not illustrated boiler of the machine itself or by another source of hot water.
In a bore of the cover 3 of the housing is provided a brake bolt 31 with a brake lining 32. The brake bolt 31 lies under a brake lever 33 which, under the action of pressure exerted at its end, may be urged downwards about an axle 34 in order to press the brake lining 32 against the upper flange of the centrifugal drum. A spring holds normally the lever 33 and the brake bolt 31 in the illustrated ineffective upper position.
Between the centrifugal drum 19 and the jacket 2b of the housing is provided a circular space 35 in which the coffee ejected towards the outside by the centrifugal drum is collected and flows from there through the dock 38 in a cup or a similar recipient. The fan blades 8 rotate in a circular space communicating with an ejecting dock 39 for the coffee grounds.
Between the hub 6 and the lower rim 26 of the coffee mill is clamped a thin arm 40, the ends of which are bent off to form two diametrically opposed thin cutters. These cutters 41 are inclined towards the front as shown by the arrow indicating the direction of rotation in FIG. 2. The arm 40 with the cutters forms a stripper for removing the coffee grounds as described later.
Coffee is prepared as follows: At first the motor is switched on. The parts connected to it, like the fan 7, 8, the stripper 40, 41 and the lower rim 26 of the coffee mill are immediately driven at the full number of revolutions. To the contrary, the plate 10, the centrifugal drum connected to it and the cover 14 are progressively set into rotation by the effective friction, whereby the number of revolutions of the parts 10 and 19 rigidly connected to each other and the one of the cover 14 must not exactly coincide. When the plate 10 reaches a determined number of revolutions, the cover 14 is lifted under the action of the balls 12 and its packing 16 is put against the lower circular opening of the centrifugal drum, between the external lower flange of the latter and the lower rim 26 of the coffee mill. The centrifugal drum is thus closed at the bottom. These movements occur in a relatively short time of e.g. one second. It is thus possible, nearly immediately after the motor has been switched on, to pour in a prepared quantity of coffee beans through the bore of the threaded tube 25. These beans are milled between the rims 22 and 26 of the coffee mill and the coffee powder is hurled against the filter-acting jacket of the centrifugal drum. Due to the fact that in the meantime the centrifugal drum is accelerated to the full speed, its number of revolutions coincide with the one of the stripper 40, 41 so that the stripper is ineffective and the building up of a layer of coffee powder is not disturbing. When the milling of the beans which have been added to the mill has been achieved, boiling water is let in through the pipe 30 and flows through the circular space 29 and the holes 28 downwards in the coffee mill and is thrown through the latter toward the exterior of the mill and against the jacket of the centrifugal drum. Residues of powder in the coffee mill are washed away so that the milled coffee in its entirety is intensively extracted. As already indicated, the coffee is extracted through the slitted filter acting jacket of the centrifugal drum and ejected in the collecting space 35. It flows in the manner already described and it can be collected at the dock 38. The milled coffee is rapidly extracted and it must then be removed from the machine. To this end, the brake is actuated by exerting a pressure on the lever 33. This produces a rapid braking of the centrifugal drum 19 and of the plate 10 rigidly connected to it as well as of the cover 14, which is still pressed against the centrifugal drum and, because the centrifugal force of the balls 12 decreases, the cover falls back in the illustrated position. The stripper 40, 41, however, rotates further at full speed whereby the cutters 41 which are inclined toward the front, strip off very rapidly and properly the coffee grounds from the internal side of the jacket of the centrifugal drum and eject them downwards through the centrifugal drum now open at the bottom. Due to the fan action of the coffee mill and more particularly of the fan, air is sucked in and the relatively dry coffee grounds are rapidly rejected through the dock 39 and are collected in a recipient not illustrated. The machine is thus cleaned. If the lever 33 is released, the plate 10 with the centrifugal drum and the cover 14 are again accelerated as previously described and coffee beans can again be poured in and processed. In this way, a plurality of coffee portions may be prepared, whereby for cleaning of the machine, it suffices to press the lever 33 when the motor is still running. It has been mentioned that the cover 14 is not necessarily accelerated as fast as the plate 10 and the centrifugal drum connected to it so that the cover may run against the edges of the opening of the centrifugal drum with a relative motion. This permits crushing and pulverizing possibly sticking coffee grains so that the latter cannot produce any leakage of the closed centrifugal drum. After each use of the coffee machine, either to prepare a single cup of coffee or more coffee protions, the machine can be washed. To this end, and with the motor still running, rinsing water is let in through the pipe 30 or, as the case may be, directly from above through the bore of the threaded tube 25. This water is accelerated by the coffee mill and hurled toward the outside to clean the centrifugal chamber and the collecting chamber and escape channels of the machine. It is advantageous to rinse the centrifugal drum at low speed by actuation of the braking lever or at rest in which case, due to the strong suction of the fan, the water hurled out through the coffee mill does not penetrate the filtering jacket of the centrifugal drum but is drawn downwards so that a certain return flow producing a backwards rinsing of the filter can take place.
If, after having prepared a cup of coffee, one forgets occasionally to press the lever 33 for removing the coffee grounds, the next charge of milled coffee is spread by running the motor on the already present coffee grounds and then also scalded. If the motor is switched out after the preparation of a single cup of coffee when the lever 33 is not actuated, the coffee grounds remain in the centrifugal drum. At the next switching on of the motor, the stripper rotates immediately at full speed and it removes the coffee grounds before the cover 14 closes the centrifugal drum 10 so that the machine is already cleaned for the preparation of a further portion of coffee.
It is indicated further that many balls 12 are uniformly distributed at the periphery in order to achieve a uniform pressure on the cover 14. In this connection, unillustrated pins may be provided or the plate 10 may be designed in the form of a cage in order to carry along the balls and to maintain them uniformly distributed at the periphery and to avoid unbalance. Weights acting on the cover 14 under the action of the centrifugal force may be used instead of the balls 12.
Various embodiments of the invention described above are possible. Even though it is advantageous to have a coffee mill built in the centrifugal drum, the machine may be conceived without such a coffee mill. In this case, milled coffee powder has to be filled up. However, this would require that an adequate centrifugal device be provided in order to distribute the coffee powder uniformly in the centrifugal chamber. The driving of the parts which are rigidly coupled with the motor is achieved in the simplest case by means of sliding clutches, as disclosed in the discussion of the preferred embodiment. If it would be necessary to define more precisely the accelerating moments, one could provide as the case may be special friction coatings, magnetic couplings or similar coupling means. The braking can also be electrically performed, e.g. by means of an electromagnet or by pneumatic or hydraulic means. This is particularly the case for large scale machines which are used for centrifuging a variety of wet materials. The opening and closing could also be performed by other means, whereby the control is rendered dependent on the number of revolutions of the plate 10 and the centrifugal drum 19. For very simple machines, the pipe 30 for scalding water is not required, in which case coffee beans are first introduced to the mill and then hot scalding water is manually introduced from above through the bore of the threaded tube 25. The coffee machine may be used in a variety of different forms and combinations, either for domestic arrangements or for industry or for automatic coffee installations. In the case of automatic coffee machines, the described procedures could be controlled automatically by a control program. The parts 2a and 2b of the housing jacket may be twisted against each other in order to adapt within certain limits the relative position of the dock 39 coupled with the lower part 2a and of the chamber 37 connected to the upper part 2b. It is also possible to mount the cover 14 with its actuating mechanism toward the top instead toward the bottom, whereby a spring, magnet or similar device could be provided to open the cover.
The principles, preferred embodiments and modes of operation of the present invention have been described in the foregoing specification. The invention which is intended to be protected herein should not, however, be construed as limited to the particular forms disclosed, as these are to be regarded as illustrative rather than restrictive. Variations and changes may be made by those skilled in the art without departing from the spirit of the present invention. Accordingly, the foregoing detailed description should be considered exemplary in nature and not limited to the scope and spirit of the invention as set forth in the attached claims.
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An apparatus is provided for centrifuging liquid from a wet material. The apparatus includes a centrifugal drum and a stripper member positioned adjacent the centrifugal drum. The front side of the centrifugal drum is open and is arranged to be closed by a cover. The stripper is firmly connected to a driving shaft when the centrifugal drum is driven by means of a sliding clutch. A brake is provided for slowing down the centrifugal drum. During the centrifuging procedure, the centrifugal drum and the stripper rotate with the same number of revolutions and the cover is closed. After the centrifuging procedure, the centrifugal drum is slowed down with respect to the stripper and the cover is opened so that the still running stripper removes and ejects the residues.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 61/248,244 filed on Oct. 2, 2009. The disclosure of the above application is incorporated herein by reference.
FEDERALLY SPONSORED RESEARCH
[0002] Certain of the research leading to the present invention was sponsored by the United States Government under National Science Foundation Grant IIP-0924053. The United States Government may have certain rights to the invention.
FIELD
[0003] The present disclosure relates to non-contact laser inspection systems and more particularly to non-contact laser inspection systems for detection of surface defects on reflective cylindrical or conical parts.
BACKGROUND
[0004] Adequate inspection of parts in a manufacturing process is desirable in order to meet part tolerances, minimize scrap and prevent defective components from being incorporated into larger subsystems. Rapid detection of defects under conditions of high volume manufacture is particularly important. If a defective part is incorporated into a larger system, the cost of disassembling the system, identifying the defect and replacing the defective part can dramatically increase production costs. Therefore, rapid detection of defects before system integration is desirable.
[0005] If parts can be inspected at the speed of a production line it may be possible to use this information for process control. If it appears that parts are drifting out of tolerance, corrective action could be taken so that defective parts are not produced. Sudden onset defects in a production system could be identified before large quantities of scrap are produced.
[0006] Some common surface defects on machined surfaces may occur randomly. These include pores, chips, and scratches. Poured metal castings contain entrained air bubbles around which liquid metal can solidify. When the castings are machined these bubbles can be cut open and exposed as pores. Chips may form when pieces of metal chip off from a casting as a tool enters or exits a hole in a part. Scratches on a surface may also make a component defective. These types of defects can be difficult to detect when they occur inside cylindrical holes in a part.
[0007] Complex parts, such as valve ports of automatic transmissions, may contain cylindrical holes that may vary progressively in diameter in discrete steps along the length of the cylinder. The cylinders may also be intersected by multiple slots. Valve ports may vary between about 8 to 24 millimeters in diameter and may have lengths over 100 millimeters. Defects in valve ports over areas as small as 0.1 mm 2 may cause problems or failure when used in automobile transmissions. Defects in such complex parts can be particularly difficult to detect rapidly with existing probes and sensors.
[0008] Non-contact gauges of various types are used to measure dimension and surface defects using optical, capacitive, eddy current and Hall-effect sensors. Most of these gauges do not measure surface finish. Imaging systems may measure geometry and surface finish, but they typically require image analysis software which may be quite slow. In addition, some geometries do not lend themselves easily to insertion of existing gauges.
[0009] Contact gauges are also used to measure dimensional accuracy and surface roughness. These gauges include coordinate measuring machines of various types and stylus gauges. Stylus gauges measure surface roughness by tracing a thin line with a diamond-tipped needle. The thin line is an extremely small fraction of the total surface area. The measurement is slow and may miss defective regions. If there are gaps in the surface, the stylus tip must be raised to avoid these gaps and avoid damage to the tip of the needle. Such characteristics make stylus gauges impractical for total part inspection on a production line.
[0010] A number of optical instruments used to detect surface flaws on reflective surfaces illuminate the surface with a directed source of illumination and place a detector in a location that will not detect specularly reflected light. Instead, the detector is generally placed to detect light scattered by a defect. If there is no defect, no signal will be received by the detector, but if there is a defect that scatters light, a signal will be received by the detector. Examples of scattered light detectors are given in U.S. Pat. Nos. 6,097,482 and 7,372,557.
[0011] Scattered light detection may be adequate when it is possible to position the light source and detector at different viewing angles that prevent reflected light from reaching the detector. However, for small diameter cylindrical holes this may not be practical or possible.
[0012] Another approach to surface defect detection uses a diffuse beam of light to illuminate a surface and a camera or other imaging system to image the surface. The data must then be analyzed using image analysis software. Examples of this type of inspection system are given in U.S. Pat. Nos. 7,394,530, 6,516,083, 6,169,600, 5,588,068, 5,353,357, and 4,732,474. In general, the illumination system and detection path are not coincident and this approach is therefore not suitable for inspecting small diameter cylinders with lengths significantly longer than the cylinder diameter.
[0013] Another technique that can inspect the inside of relatively small diameter cylinders is a confocal microscope, such as one that is commercially available from the Micro-Epsilon Corporation. This system can scan the inside of a cylinder with a focused beam of light. However, the focal spot on the surface of the cylinder is so small that a considerable time is required to scan the total area of a cylinder.
[0014] Accordingly, there is a need in the art for an improved non-contact laser inspection system capable of rapidly detecting surface defects and inspecting small diameter bores.
SUMMARY
[0015] This disclosure relates to an instrument and method for the rapid inspection of reflective surfaces of cylindrical parts for surface finish defects in a high volume production environment. A non-contact laser system uses an optical configuration in which a laser beam is directed substantially perpendicular to the surface to be inspected. Some of the laser beam light is back reflected along the trajectory of the incident beam. This makes it possible to use the detector to detect surface defects in small diameter cylindrical holes including cylinders in which the hole depth is much larger than the hole diameter. Using this system a reflective surface with no defects will produce a large optical return signal. Conversely, surface defects that scatter the incident beam will result in a dip in the return light intensity.
[0016] One embodiment of the present disclosure includes a laser probe with a thin tubular extension or tip into which a light redirecting mechanism is incorporated to permit inspection of small diameter cylinders. The probe contains a laser that produces a beam of light that is coincident with an axis of the tubular extension. A reflector in the tubular extension of the probe deflects the laser beam substantially perpendicular to the surface of the cylindrical or conical part being inspected. An optical system in the probe directs directly-back-reflected and directly back scattered light to a detector contained in the probe body. The probe body also contains electronics to amplify the detector signal. A slip ring mounted on the probe shaft permits electric power to be input to the probe and data to be retrieved while the probe is spinning. The probe is mounted on a rotatable shaft and the axis of the probe is aligned along an axis of the rotatable shaft. The rotatable shaft rotates the probe as it is inserted into a cylindrical or conical hole, so the laser beam can scan the inside of the cylindrical or conical surface. Linear and rotary encoders monitor the probe axial and angular positions. Data from the probe and from the encoders are collected using a data acquisition system and the data is analyzed and displayed using a computer and analysis and display software.
[0017] In another aspect of the present disclosure, an inspection probe for inspecting reflective cylindrical or conical surfaces of manufactured components is provided. The probe includes a laser system, an optical system, an optical detector, and a computer. The optical system directs a laser beam perpendicular to the surface being inspected and directs back-reflected light to an optical detector. The optical detector detects the back-reflected laser light from the surface.
[0018] In yet another aspect of the present disclosure, the computer includes software that compares the detected light signal to a light signature from a known cylindrical or conical surface or cylindrical or conical surface with known defects and determines a condition of the surface.
[0019] In yet another aspect of the present disclosure, the probe further includes a filter in front of the detector to reduce unwanted light.
[0020] In yet another aspect of the present disclosure, the reflective cylindrical surface is one of a valve port of a valve body or pump cover of an automatic transmission, a brake cylinder, a cylindrical reflective surface of a component of a shock absorber, the surface of a hydraulic or pneumatic cylinder, the inside surface of a gas flow valve, the inside or outside surface of a reflective cylindrical manufactured part, or a component with a tapped interior thread.
[0021] In yet another aspect of the present disclosure, the laser system, the optical system, and the detector are mounted inside a support structure.
[0022] In yet another aspect of the present disclosure, the support structure is mounted on a support shaft.
[0023] In yet another aspect of the present disclosure, the support shaft is mounted in the spindle of a machine.
[0024] In yet another aspect of the present disclosure, the laser beam is aligned along an axis of the spindle.
[0025] In yet another aspect of the present disclosure, the optical system includes an optional beam reducer to reduce the diameter of the parallel laser beam emitted along an axis of the spindle.
[0026] In yet another aspect of the present disclosure, the laser beam is reflected by an optical reflector in a direction perpendicular to the cylindrical surface to be measured.
[0027] In yet another aspect of the present disclosure, the optical system directs the return beam from the cylindrical surface onto a detector.
[0028] In yet another aspect of the present disclosure, the optical system includes a polarizing beam splitter, a quarter wave plate, an optional spacer and a 90° reflector, such as a right angle prism.
[0029] In yet another aspect of the present disclosure, the polarizing beam splitter, the quarter wave plate, the optional spacer, and the 90° reflector are attached together to form a single rigid component.
[0030] In yet another aspect of the present disclosure, the optical detector is a photodiode.
[0031] In yet another aspect of the present disclosure, the probe includes a device transmitting power to the laser and electronics in the detector and transmitting data to a computer.
[0032] In yet another aspect of the present disclosure, the power and data transmitting device is mounted on the support shaft.
[0033] In yet another aspect of the present disclosure, the power and data transmitting device is a slip ring.
[0034] In yet another aspect of the present disclosure, the probe includes a detector electronics device mounted in the support structure.
[0035] In yet another aspect of the present disclosure, the detector electronics device includes signal amplification.
[0036] In yet another aspect of the present disclosure, the shaft is rotatably supported on a chuck or tool holder.
[0037] In yet another aspect of the present disclosure, the chuck or tool holder is supported on a spindle.
[0038] In yet another aspect of the present disclosure, the spindle is supported in a computer numerically controlled (CNC) machine or robot.
[0039] In yet another aspect of the present disclosure, the CNC machine or robot is programmed to rotate and insert the probe into a reflective cylindrical component of a manufactured part.
[0040] In yet another aspect of the present disclosure, the laser beam scans the surface of the cylindrical part.
[0041] In yet another aspect of the present disclosure, the CNC machine or robot has axial and rotary encoders to determine axial position and rotation angle of the probe in the cylinder.
[0042] In yet another aspect of the present disclosure, the data acquisition system of the computer records the angular position of data points measured by the probe.
[0043] In yet another aspect of the present disclosure, data from the linear encoder is recorded by the data acquisition system.
[0044] In yet another aspect of the present disclosure, a method for inspecting a machined surface is provided. The method includes the steps of: directing a laser beam perpendicularly to the machined surface, detecting a back-reflected laser beam from the machined surface, determining a signature of the detected laser beam light, and determining a condition of the machined surface from the signature.
[0045] In yet another aspect of the present disclosure, the machined surface is a cylinder.
[0046] In yet another aspect of the present disclosure, determining a signature includes comparing a light signature from a known surface or surface with known defects to the light signature from the inner surface of the cylinder.
[0047] Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
DRAWINGS
[0048] FIG. 1 is a schematic drawing of an inspection system in an operating environment in accordance with the principles of the present disclosure;
[0049] FIG. 2 is a cross sectional view of an exemplary laser probe in accordance with the principles of the present disclosure;
[0050] FIG. 3 is a cross sectional view of an exemplary laser probe in accordance with the principles of the present disclosure;
[0051] FIG. 4 is a flow chart of a method for inspecting a bore according to the principles of the present disclosure; and
[0052] FIG. 5 is a schematic drawing of an inspection system in an operating environment in accordance with the principles of the present disclosure.
DETAILED DESCRIPTION
[0053] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It is to be understood that standard components or features that are within the purview of an artisan of ordinary skill and do not contribute to the understanding of the various embodiments of the invention are omitted from the drawings to enhance clarity. In addition it will be appreciated that the characterization of various components and orientations described herein as being “vertical” or “horizontal”, “right” or “left”, “side”, “top” or “bottom” are relative characterizations only based upon the particular position or orientation of a given component for a particular application.
[0054] With reference to FIG. 1 , a schematic diagram of inspection system 5 for inspecting workpiece 7 is shown. Inspection system 5 includes a probe 10 , probe shaft 14 , slip ring 16 , rotatable shaft 18 , positioning machine 20 , rotary encoder 22 , linear encoder 24 , data acquisition unit 26 , computer 28 , and monitor 30 .
[0055] Workpiece 7 includes an at least partially reflective inner surface 9 that defines at least one bore 12 . In the example provided, bore 12 is a valve port and workpiece 7 is a valve body or pump cover in a transmission of an automobile.
[0056] However, it should be appreciated that cylindrical bore 12 could exist in many other types of workpieces 7 , such as, but not limited to, brake cylinders, shock absorbers, hydraulic or pneumatic cylinders, gas flow valves, tapped internally threaded cylinders or other cylindrical manufactured parts.
[0057] In the example provided, inner surface 9 includes surface defect 13 . However, it should be appreciated that surface defect 13 may not be present in a given bore 12 , or many surface defects 13 may be present in a given bore 12 . In addition, bore 12 may have other diameters, depths, types of defects 13 , and numbers of defects 13 without departing from the scope of the present disclosure.
[0058] Probe 10 is disposed in bore 12 . Probe 10 is generally a laser probe, as will be described below. Probe 10 is attached to and centered on probe shaft 14 .
[0059] In the example provided, slip ring 16 is mounted on probe shaft 14 and is electrically connected to the components of probe 10 , as will be described in detail below.
[0060] Probe shaft 14 is mounted to rotatable shaft 18 of positioning machine 20 . Positioning machine 20 rotates and axially moves rotatable shaft 18 . Rotatable shaft 18 may be a solid bar or a hollow tube. In the example provided, positioning machine 20 is a computer numerically controlled (CNC) machine, and probe shaft 14 is mounted in a chuck (not shown) of rotatable shaft 18 . However, it should be appreciated that other positioning machines 20 capable of rotating probe 10 may be used without departing from the scope of the present disclosure. Standard machining techniques may be used to align the center of probe 10 with the axis of rotatable shaft 18 . The positioning machine 20 includes rotary encoder 22 and linear encoder 24 that indicate the angular orientation and the axial position of rotatable shaft 18 in the machining system. Rotatable shaft 18 and a portion of positioning machine 20 are commonly known in industry as a spindle.
[0061] Data acquisition unit 26 may be an internal data acquisition card installed in computer 28 or an external data collection unit in communication with computer 28 . However, other types of devices that perform the same functions as computer 28 may be employed without departing from the scope of the present invention. Data acquisition unit 26 is in communication with rotary encoder 22 and linear encoder 24 . In an alternative embodiment where bore 12 may be scanned without linear position data, data acquisition unit 26 is not in communication with linear encoder 24 .
[0062] Turning to FIG. 2 , further details of probe 10 are shown. Probe 10 has body portion 104 and tip portion 106 extending from body portion 104 and partially disposed within bore 12 . Body portion 104 and tip portion 106 are preferably cylindrically shaped for improved balance during rotation. The interior of body portion 104 is preferably shaped for easy insertion and removal of optic and electronic components and may be covered by a removable outer envelope (not shown) to access the interior of body portion 104 . In the example provided, tip portion 106 is a thin walled-tube about 100 millimeters in length with an outer diameter of about 3.9 millimeters. However, other shapes, diameters and lengths may be employed without departing from the scope of the present disclosure. Body portion 104 and tip portion 106 are centered along a common axis 108 . Laser 110 is mounted in body portion 104 and is aligned to emit laser beam 112 through tip portion 106 along axis 108 . Preferably, laser beam 112 has a diameter of about 1 mm. In the example provided, an optional aperture or other type of beam reducer 117 can reduce the diameter of laser beam 112 to less than 1 mm before laser beam 112 enters tip portion 106 . Laser beam 112 may return substantially along axis 108 towards laser 110 as return beam 113 . Laser beam 112 has a predetermined polarization that interacts with other components in desirable ways, as will be described below. Proper polarization of laser beam 112 may be achieved by rotational alignment of laser 110 . In the example provided, laser 110 is a diode laser that fits loosely into a cylindrical cavity in probe body 104 and can be aligned using six set screws (not shown) to both center laser 110 in probe body 104 and align laser beam 112 along probe axis 108 . Apertures and interior surfaces that may scatter light into detector 132 are made of black material or are coated black to absorb the scattered light. Tapped threads may also be added to some interior cylindrical surfaces of probe body 104 to enhance absorption of scattered light.
[0063] Polarizing beam splitter 114 is disposed on axis 108 between laser 110 and tip portion 106 . Laser 110 is oriented so that the polarization of laser beam 112 allows laser beam 112 to pass through polarizing beam splitter 114 substantially undeflected. Polarizing beam splitter 114 deflects return beam 113 due to the polarization of return beam 113 , as will be described below. Polarizing beam splitter 114 preferably deflects return beam 113 perpendicular to axis 108 .
[0064] Quarter wave plate 116 is also disposed on axis 108 between polarizing beam splitter 114 and tip portion 106 . Quarter wave plate 116 is oriented to convert the polarization of laser beam 112 from linear polarization to circular polarization. Quarter wave plate 116 also converts the polarization of return beam 113 from circular polarization to linear polarization, but in a direction that is perpendicular to the original linear polarization of laser beam 112 . Beam reducer 117 is disposed between quarter wave plate 116 and tip portion 106 .
[0065] Mirror 118 is disposed in and rotates with tip portion 106 on axis 108 . Preferably, mirror 118 is disposed near an end of tip portion 106 farthest from body portion 104 . Mirror 118 may be a separate reflector attached to probe tip 106 , and may be a cut and polished glass rod with a diameter of about 2 to 3 mm. However, other types, shapes and diameters of mirror 118 may be used without departing from the scope of the present disclosure. Mirror 118 is angled to deflect laser beam 112 perpendicular to inner surface 9 of workpiece 7 . In the example provided, mirror 118 is generally angled at 45 degrees with respect to axis 108 .
[0066] In an alternative embodiment, mirror 118 is at a different angle with respect to axis 108 in order to inspect conical surfaces, such as the sealing surface of a valve seat of an engine head. The deflection angle of mirror 118 is preferably chosen to deflect laser beam 112 perpendicular to the specified conical surface. If the surface has been machined at the specified angle, the back reflected light will produce a large signal at the detector. If the conical angle of the valve seat is incorrect or the valve seat is misaligned or defective there will be a lower detector signal.
[0067] In an alternative embodiment of a probe, a fiber optic cable (not shown) is disposed in a probe to transmit beams 112 and 113 . A laser insertion assembly (not shown) is disposed at an end of the fiber optic cable to insert laser beam 112 into the fiber optic cable. A light collimating assembly is disposed at a second end of the fiber optic cable to collimate the light from laser beam 112 exiting the fiber optic cable. Mirror 118 at the end of tip portion 106 may be used to deflect laser beam 112 perpendicular to surface 9 of bore 12 . However, other types of deflection assemblies may be used at the end of tip portion 106 to deflect laser beam 112 perpendicular to surface 9 of bore 12 .
[0068] In the example provided, optional glass spacer 124 is disposed adjacent polarizing beam splitter 114 in the path of return beam 113 . Alternatively, an opaque spacer with a centered clear aperture could be used in place of the glass spacer 124 .
[0069] Right angle prism 126 is disposed adjacent to glass spacer 124 and in the path of return beam 113 after return beam 113 has been deflected by polarizing beam splitter 114 . Right angle prism 126 is oriented to deflect return beam 113 in a direction substantially parallel to axis 108 .
[0070] In the example provided, wavelength filter 128 and neutral density filter 130 are disposed adjacent right angle prism 126 . However, in an alternative embodiment, neutral density filter 130 may be omitted, and wavelength filter 128 may be omitted when the only potential source of light reaching detector 132 is generated by laser 110 .
[0071] In the example provided, polarizing beam splitter 114 , quarter wave plate 116 , glass spacer 124 , and right angle prism 126 are held rigid by an index matching epoxy. However, the components may be held rigid in other ways without departing from the scope of the present disclosure. Preferably, any optical surface in contact with air is coated to reduce reflection.
[0072] Detector 132 is disposed adjacent neutral density filter 130 in the path of return beam 113 . Detector 132 is generally a photodiode that converts optical signals to electrical signals. However, other types of detectors 132 may be used without departing from the scope of the present disclosure.
[0073] Electrical cable 134 connects detector 132 with electronic circuit 136 . In the example provided, electronic circuit 136 is held in place by a lip at the bottom of a cavity 135 and thin collar 137 within probe body 104 . However, electronic circuit 136 may be placed in other locations and fixed within probe body 104 in other ways without departing from the scope of the present disclosure.
[0074] Probe body 104 is attached to probe shaft 14 by screws (not shown). Probe shaft 14 has a hole (not shown) through its center and a hole perpendicular to axis 108 proximate slip ring 16 . The hole through the center can enable clean low pressure compressed air to flow through the probe body and tip to create a positive pressure shielding the optical and other internal components from the outside environment. Wiring from laser 110 and wires from circuit board 136 pass through the hole perpendicular to axis 108 in probe shaft 14 and are connected to slip ring 16 . A cable (not shown) from slip ring 16 is connected to data acquisition unit 26 in computer 28 . Power cables (not shown) connect to a power supply (not shown), providing power to probe 10 .
[0075] With combined reference to FIGS. 1 and 2 , the operation of inspection system 5 will now be described. During operation, positioning machine 20 will spin probe 10 as probe 10 enters bore 12 . For a smooth cylindrical inner surface 9 , much of laser beam 112 will be reflected directly back on itself as return beam 113 . If a surface defect 13 is present, at least some of laser beam 112 will scatter and not be reflected as return beam 113 . Thus, the intensity of return beam 113 may be used to indicate the presence of surface defect 13 .
[0076] Laser beam 112 is emitted by laser 110 through polarizing beam splitter 114 , quarter wave plate 116 and beam reducer 117 , and is redirected towards inner surface 9 of workpiece 7 by mirror 118 . Upon reaching inner surface 9 , part of laser beam 112 is back reflected along the path of incident laser beam 112 . If surface defect 13 is present, at least part of laser beam 112 will not be reflected as return beam 113 . When at least part of laser beam 112 does not reflect back, any return beam 113 that does return will have lower intensity than when there is no surface defect 13 . Return beam 113 is reflected by mirror 118 through beam reducer 117 (which now may act as a beam expander) towards quarter wave plate 116 . Quarter wave plate 116 converts return beam 113 polarization so that polarizing beam splitter 114 redirects return beam 113 through spacer 124 to right angle prism 126 . Right angle prism 126 directs return beam 113 through wavelength filter 128 and neutral density filter 130 to detector 132 . When employed, neutral density filter 130 reduces return beam 113 intensity to prevent saturation of the electronic circuit 136 or data acquisition unit 26 , and wavelength filter 128 reduces the intensity of a portion of the return light corresponding to certain wavelengths. Detector 132 converts the intensity of return beam 113 into an electrical signal and sends the electrical signal through electrical cable 134 to electronic circuit 136 . Electronic circuit 136 sends a signal indicative of the intensity of return beam 113 through slip ring 16 .
[0077] Data from probe 10 is transmitted through slip ring 16 to data acquisition unit 26 in computer 28 . Data from rotary encoder 22 is also sent to data acquisition unit 26 . When a pulse is received from rotary encoder 22 , data acquisition unit 26 samples the value of the signal from probe 10 . Data from linear encoder 24 may also be sent to data acquisition unit 26 to indicate the axial location at which data from probe 10 is being sampled.
[0078] Computer 28 preferably analyzes the data from probe 10 , rotary encoder 22 , and linear encoder 24 . Preferably, software in computer 28 may create a three dimensional graph of probe 10 data as a function of position, representing surface 9 of bore 12 . The results of the analysis may be displayed on monitor 30 . The graph displayed on monitor 30 is provided to assist human visualization of surface 9 of bore 12 . The software in computer 28 obtains the information used to generate the graph and analyze the data from a data file created from data transmitted to computer 28 by data acquisition unit 26 . Alternatively, the software in computer 28 analyzes the data from data acquisition unit 26 and provides information about whether a part is acceptable or defective without generating a graph.
[0079] In an alternative embodiment, a probe is configured to inspect the outside surface of cylinders, cones, or gears by rotating the part (not shown) rather than the probe. In this embodiment, the probe does not rotate and slip ring 16 is not included because it is not needed to transmit power to and collect data from the probe. Deflecting mirror 118 may be omitted and laser beam 112 can be directed along axis 108 directly to the part being inspected. A machine (not shown) rotates the part, and has a means of determining the axial position of the probe and rotational position of the part and transmitting this information to data acquisition unit 26 collecting data from the probe. In addition to rotating the part being inspected, the machine also moves the probe linearly relative to the rotating part or moves the rotating part linearly relative to the probe in order to scan the surface of the rotating part.
[0080] The diameter of bore 12 may be determined by measuring the average intensity of return beam 113 . Smaller diameter bores 12 may have lower average return beam intensities because part of the edges of laser beam 112 may be reflected away from probe 10 due to the small radius of curvature of bore 12 .
[0081] The data obtained from probe 10 may be compared with data from a master bore known to be free of defects. The workpiece 7 can be removed for further inspection if the data between the master bore and the bore 12 of the workpiece 7 deviate from each other by a predetermined amount.
[0082] In an alternative embodiment of a probe, slip ring 16 is mounted on a second shaft (not shown). The second shaft is co-axial with and mounted to rotatable shaft 18 and is disposed on the side of rotatable shaft 18 opposite probe shaft 14 . A cable (not shown) is disposed in a bore (not shown) of rotatable shaft 18 to connect slip ring 16 with the probe. Mounting slip ring 16 on the second shaft improves the load balance on rotatable shaft 18 when the probe is mounted horizontally. Rotary encoder 22 can also be connected to the second shaft. It should be appreciated that the hole perpendicular to axis 108 in shaft 14 of the probe may be omitted. In the example provided, there is a hole on the second shaft perpendicular to axis 108 .
[0083] In an alternative embodiment of a probe, slip ring 16 is omitted and data is transmitted wirelessly from the probe to data acquisition unit 26 . An example of wireless data transmission adapted for use in the probe is given in a paper by C. Suprock, et al. titled “A Low Cost Wireless Tool Tip Vibration Sensor for Milling” in the Proceedings of the International Manufacturing Science and Engineering Conference (MSEC2008).
[0084] The data from probe 10 may also be used to determine whether axis 108 of probe 10 and an axis defined by bore 12 are coincident. If probe 10 is off center relative to the bore axis, the signal from probe 10 may be modulated with the period of the probe rotation. This modulation may be filtered out when the data is analyzed. The data may also be used as a diagnostic to monitor the relative alignment of probe 10 within bore 12 .
[0085] Another alternative embodiment that does not include a slip ring is shown in FIG. 3 , which shows a schematic diagram of inspection system 200 for inspecting workpiece 7 . Inspection system 200 includes probe 210 , base 202 , probe cover and body portion 204 , probe tip 206 , rotatable shaft 218 , rotation machine 220 , linear movement machine 223 , rotary encoder 222 , and linear encoder 224 . Rotatable shaft 218 , rotation machine 220 and rotary encoder 222 may be combined into a spindle with integral rotary encoder. Probe 210 is generally a laser probe, as will be described below. Base 202 is designed to properly position the optical and electronic components and slide along rail 226 of linear movement machine 223 .
[0086] Body portion 204 does not rotate and is rigidly mounted on and moves linearly with base 202 . The interior of body portion 204 is preferably shaped for easy insertion and removal of optic and electronic components. In the example provided, body portion 204 includes a removable outer envelope that allows access to the optic and electronic components when removed. The outer envelope of body portion 204 prevents stray light from reaching the optical components, protects the probe components from the outside environment and permits low pressure compressed air to flow through probe 210 .
[0087] Probe tip 206 may be attached to rotary shaft 218 with a chuck, tool holder, or collet (not shown). Probe tip 206 is rigidly held in rotatable shaft 218 , is rotatable with rotatable shaft 218 and is disposed in bore 12 . Probe tip 206 is centered on axis 308 . Probe tip 206 is preferably cylindrically shaped for improved balance during rotation. In the example provided, tip portion 206 is a thin walled-tube about 100 millimeters in length with an outer diameter of about 3.9 millimeters. However, other shapes, diameters and lengths may be employed without departing from the scope of the present disclosure.
[0088] Rotatable shaft 218 is centered on axis 308 and is rotatable by rotation machine 220 . Rotatable shaft 218 includes a clear through aperture 219 through an axial dimension of rotatable shaft 218 aligned with axis 308 . Rotation machine 220 is rigidly mounted on base 202 , does not rotate, and moves with base 202 along an axis of linear machine 223 . Rotation machine 220 includes aperture 221 that surrounds rotatable shaft 218 and extends through rotation machine 220 substantially along axis 308 . Rotatable shaft 218 and rotation machine 220 may be integrated into a spindle, and rotatable shaft 218 may be disposed within aperture 221 . Rotation machine 220 includes rotary encoder 222 that indicates the angular orientation of rotatable shaft 218 in inspection system 200 . In the example provided, rotary encoder 222 is aligned with rotatable shaft 218 , and includes aperture 225 that extends through rotary encoder 222 substantially along axis 308 . However, rotary encoder 222 may be placed in other locations in which case aperture 225 may be omitted without departing from the scope of the present disclosure.
[0089] Linear movement machine 223 includes linear encoder 224 and guide rail 226 . Guide rail 226 constrains movement of base 202 to linear movement along the length of guide rail 226 . Linear encoder 224 indicates the linear location of base 202 and probe tip 206 in inspection system 200 . In the example provided, linear movement machine 223 is a CNC machine. However, other machines may be used without departing from the scope of the present disclosure.
[0090] Laser 310 is mounted in body portion 204 and is aligned to emit laser beam 312 through tip portion 206 along axis 308 . Preferably, laser beam 312 has a diameter of about 1 mm. In the example provided, an aperture or other type of beam reducer 317 reduces the diameter of laser beam 312 before laser beam 312 enters tip portion 206 . In an alternative embodiment, beam reducer 317 is omitted. Laser beam 312 may return substantially along axis 308 towards laser 310 as return beam 313 . Laser beam 312 has a predetermined polarization that interacts with other components in desirable ways, as will be described below.
[0091] Polarizing beam splitter 314 is disposed on axis 308 between laser 310 and tip portion 206 . Laser 310 is oriented so that the polarization of laser beam 312 allows laser beam 312 to pass through polarizing beam splitter 314 substantially undeflected. Polarizing beam splitter 314 deflects return beam 313 due to the polarization of return beam 313 , as will be described below. Polarizing beam splitter 314 preferably deflects return beam 313 perpendicular to axis 308 .
[0092] Quarter wave plate 316 is also disposed on axis 308 between polarizing beam splitter 314 and tip portion 206 . Quarter wave plate 316 is oriented to convert the polarization of laser beam 312 from linear polarization to circular polarization. Quarter wave plate 316 also converts the polarization of return beam 313 from circular polarization to linear polarization, but in a direction that is perpendicular to the original linear polarization of laser beam 312 . Beam reducer 317 is disposed between quarter wave plate 316 and tip portion 206 . Beam reducer 317 may act as a beam expander for beam 313 .
[0093] Mirror 318 is disposed in and rotates with tip portion 206 on axis 308 . Preferably, mirror 318 is disposed near an end of tip portion 206 farthest from body portion 204 . Mirror 318 may be a separate reflector attached to probe tip 206 , and may be a cut and polished glass rod with a diameter of about 2 to 3 mm. However, other types, shapes and diameters of mirror 318 may be used without departing from the scope of the present disclosure. Mirror 318 is angled to deflect laser beam 312 perpendicular to inner surface 9 of workpiece 7 . In the example provided, mirror 318 is generally angled at 45 degrees with respect to axis 108 . However, it should be appreciated that mirror 318 may have other angles with respect to axis 308 , such as when inspection of a conical surface is desired, without departing from the scope of the present disclosure.
[0094] Glass spacer 324 is disposed adjacent polarizing beam splitter 314 in the path of return beam 313 . However, in an alternative embodiment, glass spacer 324 is omitted. In another alternative embodiment, glass spacer 324 may be replaced with an opaque spacer with an aperture at its center to permit the return beam to pass through to detector 332 . Right angle prism 326 is disposed adjacent to glass spacer 324 and in the path of return beam 313 after return beam 313 has been deflected by polarizing beam splitter 314 . Right angle prism 326 is oriented to deflect return beam 313 in a direction substantially parallel to axis 308 . In an alternative embodiment, glass spacer 324 and right angle prism 326 are omitted. Such an alternative embodiment may be desirable because the spatial constraints on the location of the optical components are more relaxed than are the spatial constraints in an embodiment with a rotating probe body.
[0095] In the example provided, wavelength filter 328 and neutral density filter 330 are disposed adjacent right angle prism 326 . However, in an alternative embodiment, neutral density filter 330 is omitted, and wavelength filter 328 is omitted when the only potential source of light reaching detector 332 is generated by laser 310 .
[0096] In the example provided, polarizing beam splitter 314 , quarter wave plate 316 , glass spacer 324 , and right angle prism 326 are held rigid by an index matching epoxy. However, the components may be held rigid in other ways without departing from the scope of the present disclosure. Preferably, any optical surface in contact with air is coated to reduce reflection.
[0097] Detector 332 is disposed adjacent neutral density filter 330 in the path of return beam 313 . It should be appreciated that detector 332 is disposed in the alternative path of return beam 313 when right angle prism 326 and glass spacer 324 are omitted. Detector 332 is generally a photodiode that converts optical signals to electrical signals. However, other types of detectors 332 may be used without departing from the scope of the present disclosure.
[0098] Electrical cable 334 connects detector 332 with electronic circuit 336 and cable 338 transmits data from electronic circuit 336 to computer 28 .
[0099] With continued reference to FIG. 3 , the operation of inspection system 200 will now be described. During operation, rotation machine 220 will spin rotatable shaft 218 which spins probe tip 206 as linear movement machine 223 linearly moves base 202 so that probe tip 206 enters bore 12 . For a smooth cylindrical inner surface 9 , much of laser beam 312 will be reflected directly back on itself as return beam 313 . If a surface defect 13 is present, at least some of laser beam 312 will scatter and not be reflected as return beam 313 . Thus, the intensity of return beam 313 as a function of position of the laser spot on surface 9 may be used to indicate the presence of surface defect 13 .
[0100] Laser beam 312 is emitted by laser 310 through polarizing beam splitter 314 , quarter wave plate 316 , beam reducer 317 , aperture 225 in rotary encoder 222 , aperture 219 in rotatable shaft 218 , and probe tip 206 and is redirected towards inner surface 9 of workpiece 7 by mirror 318 . Upon reaching inner surface 9 , part of laser beam 312 is back reflected along the path of incident laser beam 312 . If surface defect 13 is present, at least part of laser beam 312 will not be reflected as return beam 313 . When at least part of laser beam 312 does not reflect back, any return beam 313 that does return will have lower intensity than when there is no surface defect 13 . Return beam 313 is reflected by mirror 318 through probe tip 206 , aperture 219 in rotatable shaft 218 , aperture 225 in rotary encoder 222 , and beam reducer 317 (which now may act as a beam expander) towards quarter wave plate 316 . Quarter wave plate 316 converts return beam 313 polarization so that polarizing beam splitter 314 redirects return beam 313 through spacer 324 to right angle prism 326 . Right angle prism 326 directs return beam 313 through wavelength filter 328 and neutral density filter 330 to detector 332 . When employed, neutral density filter 330 reduces return beam 313 intensity to prevent saturation of the electronic circuit 336 or data acquisition unit 26 , and wavelength filter 328 reduces the intensity of the return light corresponding to certain wavelengths. Detector 332 converts the intensity of return beam 313 into an electrical signal and sends the electrical signal through electrical cable 334 to electronic circuit 336 . Electronic circuit 336 sends a signal indicative of the intensity of return beam 313 through cable 338 .
[0101] Data from probe 210 is transmitted through cable 338 to data acquisition unit 26 in computer 28 . Data from rotary encoder 222 is also sent to data acquisition unit 26 . When a pulse is received from rotary encoder 222 , data acquisition unit 26 samples the value of the signal from probe 210 . Data from linear encoder 224 may also be sent to data acquisition unit 26 to indicate the axial location at which data from probe 10 is being sampled.
[0102] Referring now to FIG. 4 , with continued reference to FIGS. 2 and 3 , a method of inspecting bore 12 using probe 10 is described and is generally indicated by reference number 400 . Starting in block 402 , acceptable characteristics and characteristics of defects of inner surface 9 within bore 12 are determined. Defect characteristics may indicate the type and size of defect and size of defects 13 on inner surface 9 , a surface roughness parameter of the surface or geometric information about the cylinder. However, other characteristics may be used in block 402 . Acceptable characteristics may be the same or similar indicators having different sizes, numbers, parameters, or geometries. In the example provided, defect characteristics are determined and used through the method. However, acceptable characteristics or both acceptable characteristics and defect characteristics may be used.
[0103] In block 404 , signal patterns, including intensity thresholds, corresponding to defects or surface patterns indicative of surface defects from block 402 are determined.
[0104] In block 406 , a workpiece 7 including bore 12 with inner surface 9 is provided and probe 10 is inserted into bore 12 in block 408 . In block 410 , scanning begins by directing laser beam 112 perpendicular to inner surface 9 of bore 12 . The intensity of return beam 113 that reflects perpendicular to inner surface 9 of bore 12 is measured in block 412 and is stored in block 414 . In the example provided, the intensity values of sampled points of return beam 113 are stored as a data file.
[0105] In block 416 , the probe is rotated within bore 12 . The angle of rotation of probe 10 within bore 12 is measured in block 418 and is stored in block 420 . In block 422 , the depth of probe 10 within bore 12 is adjusted. The depth of probe 10 within bore 12 is measured in block 424 and is stored in block 426 . In the example provided, blocks 416 to 420 and 422 to 426 are performed simultaneously with blocks 410 to 414 . However, blocks 416 to 420 and 422 to 426 may be performed separately from each other and from blocks 410 to 414 without departing from the scope of the present disclosure.
[0106] In decision block 427 , it is determined whether the travel of probe 10 within bore 12 has met predetermined conditions for the amount of bore 12 to be scanned. In the example provided, the predetermined conditions are selected to correspond to scanning the entire length of bore 12 . However, the predetermined conditions may be selected to correspond to scanning less than the entire length of bore 12 . If the predetermined conditions are not met, the method returns to block 410 where scanning will continue. If the predetermined conditions have been met, the method proceeds to block 428 .
[0107] In an example of steps 410 to 427 , probe 10 is rotated in a low pitch screw path to scan the surface of the cylinder with laser beam 112 directed perpendicular to the inner surface 9 of bore 12 . Positioning machine 20 moves probe 10 towards the starting position of the scan in or near bore 12 . When probe 10 has reached the starting position linear encoder 24 sends a signal to the CNC control program. After receiving the signal from linear encoder 24 , the CNC control program begins spinning probe 10 . Rotary encoder 22 sends different signals to data acquisition unit 26 at different intervals. Index signals are sent at index intervals corresponding to a certain angular orientation of probe 10 . Sample signals are recorded at intervals predetermined from the rotary orientation of probe 10 and fixed in number during every full rotation of probe 10 . When the probe begins to spin, data acquisition unit 26 looks for the next index signal from rotary encoder 22 and begins sampling data after receiving the index signal. Data acquisition unit 26 takes and stores samples of continuously streaming data from detector 132 at every sample signal pulse from rotary encoder 22 until a predetermined number of pulses that indicate a full scan have been received. Computer 28 calculates the angle for each data point from the angle at which the index pulse is emitted, the known number of pulses per revolution and the order of a particular sample in the stored data file. However, it should be understood that the method of taking data from probe 10 may take other forms without departing from the scope of the present invention.
[0108] In block 428 , a return beam pattern is determined from the intensity of return beam from block 414 , the probe angle from block 420 , and the depth of probe 10 within bore 12 from block 422 . In block 430 , the return beam pattern is compared with the signal patterns determined in block 404 and it is determined whether the return beam pattern matches the signal pattern in decision block 432 . In the example provided, if the return beam pattern matches the threshold for the signal pattern of a defect then a defect has been detected and inspection system 5 indicates that the defect is present in block 434 . The workpiece 7 will be removed from the production line for further inspection. If the return beam pattern does not match the threshold for the signal pattern of a defect then no defect is detected and inspection system 5 indicates that the defect is not present in block 436 . The workpiece 7 will continue as part of the production stream and the method is complete. It should be appreciated that blocks 428 to 430 may be performed before the predetermined conditions of block 427 have been met, and the scan may be interrupted if a defect is detected. Of course, the present invention contemplates that method 400 may be repeated to inspect other surfaces or other parts.
[0109] In additional steps, even when no individual signal pattern meets the threshold for a defect, the recorded signal patterns of different inspected components may be compared to determine whether variations in signal patterns are changing monotonically over time. If the signal pattern variations are changing monotonically then the computer may generate a message to indicate a drift in the production stream that may eventually result in defects on production parts. Detecting this drift can enable corrections to the production process to be made before a defect is actually generated, thus preventing the production of defective parts.
[0110] With reference now to FIG. 5 , a schematic diagram of inspection system 500 for inspecting workpiece 502 is shown. Inspection system 500 includes probe 10 , probe shaft 14 , slip ring 16 , rotatable shaft 18 , positioning machine 20 , rotary encoder 22 , and linear encoder 24 .
[0111] Workpiece 502 is mounted on part positioning fixture 504 and includes an at least partially reflective inner surface 506 that circumscribes axis 108 and defines at least one bore 507 . Workpiece 502 also includes a conical portion or conical member 508 having an angled surface 510 that is at an angle different from the angle of the inner surface 506 . In the example provided, workpiece 502 is an engine head of an internal combustion engine, bore 507 is a valve guide, and conical member 508 is a valve seat. However, it should be appreciated that other types of bores and conical surfaces within other types of workpieces may be inspected by inspection system 500 .
[0112] Inspection system 500 further includes a conical mirror 512 having a conical mirror surface 514 circumscribing axis 108 . Conical mirror surface 514 defines a bore 515 that accommodates probe tip 106 of probe 10 as probe 10 moves along axis 108 during inspection. The angle of conical mirror surface 514 is selected to direct laser beam 112 from probe 10 perpendicular to angled surface 510 of conical member 508 . Conical mirror 512 is fixed to a mirror mounting and positioning fixture 516 which is attached to fixed platform 518 . In the example provided, fixed platform 518 does not move along axis 108 .
[0113] With continued reference to FIG. 5 , the operation of inspection system 500 will now be described. Laser beam 112 exits probe 10 perpendicular to axis 108 and then reflects off of conical mirror surface 514 of conical mirror 512 towards and perpendicular to angled surface 510 of conical member 508 . When laser beam 112 reaches the angled surface 510 of conical member 508 , at least a portion of laser beam 112 reflects back towards conical mirror 512 as return beam 113 . Return beam 113 then reflects off of conical mirror surface 514 towards probe 10 , where the intensity of return beam 113 and the alignment of conical member 508 relative to axis 108 are determined. In the example provided, after inspecting angled surface 510 of conical member 508 , probe 10 continues moving axially through conical mirror 512 into bore 507 where probe 10 inspects the alignment of bore 507 relative to the axis 108 . Using the measurements from conical member 508 and bore 507 , probe 10 determines whether conical surface 510 is concentric with bore 507 of workpiece 502 .
[0114] In an alternative embodiment for determining whether a conical surface and a cylindrical surface are concentric, a first probe has a first mirror angled to inspect the conical surface of a valve seat and a second probe with a second mirror angled at 45° to inspect a valve guide hole. The first and second probes may be sequentially moved to the same measurement position relative to the valve guide to inspect both the valve seat and the valve guide hole.
[0115] The present invention has many advantages over the prior art. A probe according to the present disclosure may scan the entire inner surface of bores having varying diameters. The probe may complete the inspection rapidly enough to be used on a production line.
[0116] While the preferred modes for carrying out the invention have been described in detail, it is to be understood that the terminology used is intended to be in the nature of words and description rather than of limitation. Those familiar with the art to which this invention relates will recognize that many modifications of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced in a substantially equivalent way other than as specifically described herein.
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A non-contact laser inspection system includes a probe with a thin tubular extension into which a light redirecting mechanism is incorporated to permit inspection of small diameter cylinders. The laser inspection system contains a laser that produces a beam of light that is coincident with an axis of the probe body. A reflector in the tip of the probe deflects the laser beam perpendicular to the axis of the probe. An optical system in the probe directs directly back reflected light to a detector contained in the probe body. The probe is mounted in a rotatable shaft and the axis of the probe is aligned along the axis of the rotatable shaft. The rotatable shaft rotates the probe as it is inserted into a cylindrical hole, so the laser beam can scan the inside of the cylindrical surface.
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FIELD OF THE INVENTION
[0001] The present invention relates to the field of communications and in particular to multi-screen service (which provides a multimedia service for at least two of a television set, a personal computer and a handheld portable terminal of a certain user) and the serving technology thereof.
BACKGROUND OF THE INVENTION
[0002] In recent years, multi-screen service has gained increasing attention along with the development of mobile communications. The multi-screen service requires a service provider to extend various communication services, particularly multimedia contents to various end devices, e.g., a television set, a personal computer, a handheld portable terminal, etc., so as to provide real multi-screen experience. The multi-screen service will bring a significant viscosity of users to thereby enhance competitive advantage of the communication service provider.
[0003] Microsoft has once developed its uniform communication experience with such a fundamental concept of providing the ability to access a communication service in any device anywhere and anytime. Multi-screen experience available from Alcatel-Lucent embodies the same fundamental concept. The multi-screen service allows the service provider to provide a user with a personalized service so as to improve user experience. The multi-screen service enables the user to move from one place to another and to receive subscribed content through any of various end devices, e.g., a television set, a personal computer, a handheld portable terminal, etc.
[0004] One existing method of notifying a multi-screen service user is to transmit a short message. However, a uniform short message format for feeding back user's service requirement of the multi-screen service is absent among different handheld portable terminals. More importantly, the short message may be subject to such a long delay which is typically variable that a server cannot make a timely response to a short message command of the user, thus degrading the quality of service.
[0005] Another method of enabling a user to interact is to encapsulate a service request command input by a user on a 3G mobile phone into user data application part in the 3GPP protocol to thereby perform rapid interaction of request command for multi-party conference in 3G networks. However, this method is suitable for a video conference based upon circuit switching, which requires that the communication system has to be deployed over WCDMA (i.e., 3GPP) network in the 3G network and both the mobile phone of the user and network devices have to support the 3GPP protocol and H.323 and H.324 protocols, and the user has to input the service request command in intricate hexadecimal numbers due to the limitation of 3GPP user data application part protocol. Also, since the user data application part protocol is based upon T.120 and T.140 protocols in the circuit domain, data in the user data application part has to firstly be encapsulated into H.323 and H.324 protocols and be H.323-multiplexed prior to transmission and then H.323-demultiplexed upon arriving at the other end, which will undoubtedly increase the computation load of the user's 3G mobile phone and the network devices as well as prolong the delay. In summary, this video conference-oriented method (based upon circuit switching) cannot be applied to the multi-screen service based upon IP packet switching due to its limitation and specialization.
[0006] Therefore it is desirable to provide a mechanism for new service notification and interaction in the existing multi-screen service solution.
SUMMARY OF THE INVENTION
[0007] In order to address the foregoing problem present in the prior art, the invention proposes a method and apparatus for notification and interaction of a multi-screen service in a communication system.
[0008] According to a first aspect of the invention, there is provided a method of collecting a multi-screen service request of a user in a network device of a communication network, which includes the steps of: A. transmitting, to a handheld portable terminal of the user, an OMA interactive media document, the OMA interactive media document comprising multimedia service notification information and at least one set of media objects comprising a multi-screen service request command template; and B. receiving a multi-screen service request command fed back from the user and determining a requirement of the user on a multi-screen service according to the multi-screen service request command.
[0009] According to a second aspect of the invention, there is provided a method of requesting a multi-screen service in a handheld portable terminal of a communication network, which includes the steps of: a. receiving, from a network device, an OMA interactive media document, the OMA interactive media document including multimedia service notification information and at least one set of media objects including a multi-screen service request command template; b.
[0010] acquiring the multi-screen service request command template in the set of media objects according to a protocol supported by the handheld portable terminal; c. editing a multi-screen service request command based on the acquired multi-screen service request command template according to a user input; and d. transmitting the multi-screen service request command to the network device.
[0011] According to a third aspect of the invention, there is provided a collecting apparatus for collecting a multi-screen service request of a user in a network device of a communication network, which includes: a first transmitting means for transmitting, to a handheld portable terminal of the user, an OMA interactive media document, the OMA interactive media document including multimedia service notification information and at least one set of media objects including a multi-screen service request command template; and a first receiving means for receiving a multi-screen service request command fed back from the user and determining a requirement of the user on a multi-screen service according to the multi-screen service request command.
[0012] According to a fourth aspect of the invention, there is provided a requesting apparatus for requesting a multi-screen service in a handheld portable terminal of a communication network, which includes: a second receiving means for receiving from a network device an OMA interactive media document, the OMA interactive media document including multimedia service notification information and at least one set of media objects including a multi-screen service request command template; a template acquiring means for acquiring the multi-screen service request command template in the set of media objects according to a protocol supported by the handheld portable terminal; a command editing means for editing a multi-screen service request command based on the acquired multi-screen service request command template according to a user input; and a second transmitting means for transmitting the multi-screen service request command to the network device.
[0013] There exists no method of defining a uniform multi-screen service request command using the OMA standard so far in the prior art. In the present invention, a uniform multi-screen service request command template is defined by using an OMA interactive media document so that a notification of a network device about a multi-screen service and a request command of a user for multi-screen service content are compatible with the Open Mobile Alliance (OMA) standard. With the multi-screen service request command template defined in the OMA interactive media document in the invention, the user can create a request command simply and rapidly to thereby greatly reduce the probability of an input error of the user, and it is not necessary to set up a connection in advance, thus greatly improving the quality of experience of the user and shortening a delay. The network device can make a timely and accurate response to the request command of the user due to the uniform command template in use at a client.
[0014] Furthermore, the different embodiments of the method and device according to the invention can further offer a part or all of the following advantages:
[0015] 1) The network device can provide the user with a WAP/WWW page or link with which the request command can be transmitted conveniently so that the user is provided with a new approach to request a multi-screen service more simply and conveniently through a personal computer or a handheld terminal.
[0016] 2) With the uniform command template of the invention, a software developer of the client can correspondingly make a more friendly input control interface, e.g., a dropdown menu, an input box, or a temporarily pop-up help box attached thereto etc., so that the user can edit the multi-screen service request command using simple operations, e.g., of inputting a number, selecting some options, etc.
[0017] Along with the globalized development of the OMA, the production value of OMA members has occupied more than 90% of the total production value of mobile communications. With the use of the OMA application protocol, the invention can be applied to any radio communication system in support of the OMA, e.g., various radio communication networks of 2.5G, 3G, WiMAX, LTE, 4G, etc. as well as an a hybrid network consisted of those networks.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Other features, objects and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the drawings in which:
[0019] FIG. 1 illustrates a schematic structural diagram of a communication system according to an embodiment of the invention;
[0020] FIG. 2 illustrates a flow chart of a systematic method according to an embodiment of the invention;
[0021] FIG. 3 illustrates a schematic diagram of an OMA interactive media document including a multi-screen service request command template according to an embodiment of the invention;
[0022] FIG. 4 illustrates a block diagram of a collecting apparatus for collecting a multi-screen service request of a user in a network device of a communication network according to an embodiment of the invention; and
[0023] FIG. 5 illustrates a block diagram of a requesting apparatus for requesting a multi-screen service in a handheld portable terminal of a communication network according to an embodiment of the invention.
[0024] Identical or like reference numerals will denote identical or like step features or means (modules).
DETAILED DESCRIPTION OF THE INVENTION
[0025] FIG. 1 illustrates a schematic structural diagram of a communication system according to an embodiment of the invention. As illustrated, the system includes a network device 1 and user terminals 2 a , 2 b and 2 c . The user terminals can be any type of end devices capable of receiving information or performing information interaction over a network, particularly an end device capable of receiving multimedia information, e.g., a desktop computer, a notebook computer, a mobile phone, a Personal Digital Assistant (PDA), a television set, etc. The user terminals 2 a , 2 b and 2 c as illustrated belong to the same user, for example but not limited thereto, the user terminal 2 a is a mobile phone, the user terminal 2 b is a television set, and the user terminal 2 c is a computer, and the user can receive multi-screen service content through any of the terminal devices, where notification and request interaction of the multi-screen service can be performed between the network device 1 and the user terminal 2 a by using an OMA interactive media document. In the drawing, dotted lines represent a notification of the multi-screen service and a multi-screen service request command which are interacted between the network device 1 and the user terminal 2 a , and solid lines represent transmission of multi-screen service content. Those skilled in the art shall appreciate that transmission of multi-screen service content can be performed by the network device 1 or another server mutually independent of the network device 1 .
[0026] Those skilled in the art shall appreciate that FIG. 1 illustrates just an embodiment and the communication system providing the multi-screen service will not be limited to the structure in FIG. 1 . The user in the system may not necessarily possess all the three types of end devices, i.e., the mobile phone, the television set and the computer; for example, the user can posses the mobile phone and the television set, or the user can posses the mobile phone and the computer. The user can receive multi-screen service content through any of the end devices he possesses, and interaction of the notification and the request of the multi-screen service can be performed between the network device and the handheld portable terminals of the user by using an OMA interactive media document.
[0027] FIG. 2 illustrates a flow chart of a systematic method according to an embodiment of the invention. The invention will be set forth below from the perspective of a method with reference to FIG. 1 and FIG. 2 by describing a flow of a method for collecting a multi-screen service request of a user in a network device of a communication network and a flow of a method for requesting a multi-screen service in a handheld portable terminal of a communication network.
[0028] The following steps will be performed at the side of the network device 1 :
[0029] Firstly in the step S 12 , the network device 1 transmits an OMA interactive media document to the user terminal 2 a , i.e., the handheld portable terminal of the user, where the OMA interactive media document includes multimedia service notification information and at least one set of media objects including a multi-screen service request command template.
[0030] A playing terminal of a multi-screen service can be a handheld portable terminal, a television set or a computer, and typically only the handheld portable terminal can be carried around with the user and on standby all the time, so transmitting the service request command template to the handheld portable terminal facilitates a timely feedback from the user.
[0031] Various mobile networks exist, and handheld portable terminals of the different mobile networks support different protocols. For compatibility with various systems, protocols and devices, the OMA interactive media document transmitted by the network device 1 can include a plurality of sets of media objects, each of which corresponds to a multi-screen service request command template based upon a specific protocol. For example but not limited thereto, a set of media objects can be a multi-screen service request command template based upon the OMA protocol or a multi-screen service request command template based upon the SMS protocol or a multi-screen service request command template based upon the SIP protocol or a link to a multi-screen service request command shortcut control page. Such link can be a link based upon the WAP protocol or a web link based upon the HTTP protocol.
[0032] FIG. 3 illustrates a schematic diagram of an OMA interactive media document including a multi-screen service request command template according to an embodiment of the invention. As illustrated in FIG. 3 , the OMA interactive media document transmitted by the network device 1 preferably includes all the four sets of media objects, i.e., a multi-screen service request command template based upon the OMA protocol, a multi-screen service request command template based upon the SMS protocol, a multi-screen service request command template based upon the SIP protocol and a link to a multi-screen service request command shortcut control page. Of course the OMA interactive media document transmitted by the network device 1 can alternatively include two, three or even only one of the foregoing sets of media objects and can further include a multi-screen service request command template based upon another protocol. The user terminal 2 a can determine one of the multi-screen service request command templates according to its supported protocol, edit a multi-screen service request command according to the determined template and feed it back to the network device 1 .
[0033] The user receiving a multi-screen service is interested particularly in three W's (What, Where and When), i.e., multi-screen service content, a playing terminal and playing time. Therefore, the multi-screen service request command template preferably includes information related to the foregoing three items. Those skilled in the art shall appreciate that information related to the multi-screen service content, the playing terminal and the playing time can be in the form of a string of characters, a number or another identifier. For example the three types of playing terminals can be identified in a string of characters respectively as “Mobile”, “PC” and “TV” or numerically respectively as “001”, “002” and “ 003 ”. Correspondingly, the multi-screen service request command fed back from the user terminal 2 a further includes a requirement of the user on the multi-screen service content, the playing terminal and the playing time.
[0034] As described above, the multi-screen service request command template includes a number of elements, e.g., multi-screen service content, a playing terminal, playing time, etc. With the purpose of a uniform command format, an arrangement order of the respective elements shall be specified in the multi-screen service request command template. For example, a request command template in which a playing terminal, playing time, a playing date and service content are arranged in that order can be represented as {______, ______:______, yy/mm/dd, ______}; and the OMA interactive media document can further include the definitions of respective fields of the template and a guidance regarding how the user constructs his or her own request command. Alternatively, the request command template can be an already well edited request command, and a part or all of the fields therein can be modified by the user as desired; for example, a request command template can be represented as {Mobile,9:00,20090615,NBA Final 2009 #5}, where the underlined fields can be modified by the user. The description for the format of the multi-screen service request command template herein is merely illustrative but not limiting.
[0035] Furthermore, the OMA interactive media document can further include multi-screen service notification information, which can include any one or more of the title of multi-screen service content, default playing time, a charging criterion, a charging mode and multimedia digest information of the multi-screen service content. For example, if an item of new multi-screen service content is a film, then multi-screen service notification information can include the title of the film and corresponding multimedia digest information including a brief literal introduction and/or a video clip of the film. The user can decide whether to receive the entire film by watching the brief literal introduction and/or the video clip of the film. In another example, an item of new multi-screen service content is an impending football match, then multi-screen service notification information can include the title of the football match, default playing time, a charging criterion, multimedia digest information, etc., where the default playing time is live show time of the football match, the charging criterion can charge the user differently dependent upon whether he or she watches a live show or a video record, and the multimedia digest information can include a brief literal introduction of the match and/or a historical video of two competing sides of the match. The user can decide whether to watch the match according to the multimedia digest information and decide whether to watch the live show or the video record according to the charging criterion. The quality of user experience can be enhanced greatly by adding the abundant notification information related to the multi-screen service into the OMA interactive media document transmitted to the handheld portable terminal of the user.
[0036] Different users have different preferences of multi-screen service content. For example, some users prefer to a sport program while some prefer to current political news. Furthermore, different users possess different end devices, that is, posses different ranges of available playing terminals. For example, some users possess a handheld portable terminal and a television set, some users possess a handheld portable terminal and a computer, and some users possess all of a handheld portable terminal, a television set and a computer. Therefore, preferably, the step of determining the OMA interactive media document according to a subscription agreement of the user is further included before the step S 12 .
[0037] Specifically, the user can select the type of the multi-screen service he or she wishes to receive upon subscribing to the multi-screen service, and the network device 1 determines the multi-screen service notification information and the multi-screen service request command template in the OMA interactive media document to be transmitted to the user according to the subscription agreement of the user. Users can be grouped according to their different subscription requirements. For example but not limited thereto, users who have subscribed to a sport program are grouped together; and when there is new content of the sport program, the network device 1 multicasts, to handheld portable terminals of this group of users, an OMA interactive media document with multi-screen service notification information including information related to the new content of the sport program. Multi-screen service content with a very high attention rate can be set by default as being possibly received by all the users. For example, when there is content of a live show of an Olympic Games opening ceremony or a live show of the 60th anniversary of National Day, the network device 1 can broadcast, to handheld portable terminals of all the users, an OMA interactive media document with multi-screen service notification information including information related to the corresponding content. Of course, the network device 1 can alternatively transmit individually, to a handheld portable terminal of a specific user, an OMA interactive media document with multi-screen service notification information including information related to content of a unique type of service to which the user subscribes.
[0038] Furthermore, information related to a multi-screen service playing terminal in the multi-screen service request command template can include any one or more of identification information of a handheld portable terminal, identification information of a computer and identifier information of a television set. Specifically, the user can select a range of available playing terminals for receiving the multi-screen service upon subscribing to the multi-screen service, and the network device 1 determines information related to a multi-screen service playing terminal in the multi-screen service request command template in the OMA interactive media document to be transmitted to the user according to the subscription agreement of the user. For example, a user possesses a handheld portable terminal and a computer, and the range of available playing terminals selected by him upon subscribing to the multi-screen service includes only a handheld portable terminal and a computer, and the network device 1 transmits, to the handheld portable terminal of the user, an OMA interactive media document with a multi-screen service request command template carrying information related to a playing terminal including identification information of the handheld portable terminal and identification information of the computer. In another feasible solution, the information related to a playing terminal carried by the multi-screen service request command template in the OMA interactive media document transmitted by the network device 1 to the to a handheld portable terminal of any user includes all the identification information of the three playing terminals, and the multi-screen service request command template further includes status information of the respective playing terminals so that the network device 1 sets part or all of the status information of the three playing terminals to “Available” and the other status information to “Unavailable” according to the subscription agreement of the user.
[0039] All of the foregoing scenarios in which the OMA interactive media document is determined according to the subscription agreement of the user are merely illustrative but not limitative of the invention, and those skilled in the art can make other variation or modifications in light of the foregoing description. Furthermore, those skilled in the art shall appreciate that the subscription agreement of the user can be updated as required for the user. For example, the type of the multi-screen service and/or the range of available playing terminals can be updated.
[0040] According to an embodiment of the invention, the multi-screen service request command template in the OMA interactive media document transmitted to the handheld portable terminal of the user can further include information related to a transmission priority of the multi-screen service. Thus, the user can be provided with selection for different qualities of service.
[0041] As described above, the set of media objects in the OMA interactive media document can include a link to a multi-screen service request command shortcut control page, which can be a link based upon the WAP protocol or a link based upon the HTTP protocol. In the page to which the link points, information related to multi-screen service content, a playing terminal, playing time, etc. can be included, and a dropdown menu of options, an input box or another edition control can be set to thereby provide the user with an approach to request a multi-screen service more simply and conveniently. Furthermore, the page can further include multimedia digest information related to multi-screen service content to facilitate a selection by the user and improve the quality of user experience. The user can access a multi-screen service request command shortcut control page based upon the HTTP protocol and perform a corresponding operation such as inputting a number or selecting some options through the user terminal 2 c , i.e., the personal computer. In response to the input of the user, the edition control built in the page will automatically generate and transmit the multi-screen service request command to the network device 1 . Those skilled in the art shall appreciate that the network device 1 and a server for providing the multi-screen service request command shortcut control page can be the same device or devices independent of each other.
[0042] In the step S 14 , the network device 1 receives the multi-screen service request command fed back from the user and determines the requirement of the user on the multi-screen service according to the multi-screen service request command. As described above, the multi-screen service request command fed back from the user can come from the handheld portable terminal of the user, e.g., the user terminal 2 a , etc., or the server providing the multi-screen service request command shortcut control page.
[0043] Specifically, for example, the user terminal 2 a feeds back a multi-screen service request command based upon the OMA protocol with the content of {Mobile, 9:00, 20090615, NBA Final 2009 #5; PC, None; TV, 21:00, 20090615, NBA Final 2009 #5}, and the network device 1 can determine, according to the request command, that: the user requests watching a live show of the 5 th round of NBA Finals, 2009 at 9:00 on his or her handheld portable terminal, i.e., the user terminal 2 a , and a video record of the same match on his or her television set at 21:00. Those skilled in the art shall appreciate that the foregoing form and content of the multi-screen service request command are merely illustrative but not limitative of the invention.
[0044] The following steps will be performed at the side of the user terminal 2 a , i.e., the handheld portable terminal of the user:
[0045] Firstly in the step S 21 , the user terminal 2 a receives the OMA interactive media document from the network device 1 , where the OMA interactive media document includes at least one set of media objects including a multi-screen service request command template.
[0046] As described above, the OMA interactive media document transmitted by the network device 1 preferably include four sets of media objects, i.e., a multi-screen service request command template based upon the OMA protocol, a multi-screen service request command template based upon the SMS protocol, a multi-screen service request command template based upon the SIP protocol and a link to a multi-screen service request command shortcut control page respectively. Of course, the OMA interactive media document transmitted by the network device 1 can alternatively include two, three or even only one of the foregoing sets of media objects and can further include a multi-screen service request command template based upon another protocol.
[0047] Then in the step S 23 , the user terminal 2 a can acquire the multi-screen service request command template in the set of media objects according to its supported protocol.
[0048] Specifically, the protocol supported by the user terminal 2 a can include any one or more of the OMA protocol, the SMS protocol, the SIP protocol, the WAP protocol and the HTTP protocol.
[0049] In a very possible scenario, the OMA interactive media document received by the user terminal 2 a includes a plurality of sets of media objects, which are a multi-screen service request command template based upon the OMA protocol, a multi-screen service request command template based upon the SMS protocol, a multi-screen service request command template based upon the SIP protocol and a link to a multi-screen service request command shortcut control page based upon the WAP protocol and/or the HTTP protocol, respectively. According to some embodiments of the invention, if the user terminal 2 a supports more than one of the foregoing protocols, e.g., the OMA protocol, the SMS protocol, the SIP protocol, the WAP protocol, etc., then the user terminal 2 a can fetch a plurality of multi-screen service request command templates respectively based upon the different protocols. Preferably, the user terminal 2 a will determine a multi-screen service request command template in a set of media objects corresponding to one of its supported protocols according to a predetermined rule. For different purposes, the predetermined rule here can be any one or more of the following: a transmission time for the multi-screen service request command based upon the determined protocol being the shortest; a bandwidth resource occupied by the multi-screen service request command based upon the determined protocol being the least. For example, the user terminal 2 a can select the command template based upon the OMA protocol or the command template based upon the SIP protocol in order to achieve the least transmission time for the fed-back multi-screen service request command.
[0050] Then in the step S 27 , the user terminal 2 a edits a multi-screen service request command based upon the acquired multi-screen service request command template according to an input of the user.
[0051] For example, the user terminal 2 a has determined the multi-screen service request command template based upon the OMA protocol in the step S 23 and then edits, in the step S 27 , a multi-screen service request command in compliance with the OMA protocol based upon the determined template according to an input of the user.
[0052] According to some embodiments of the invention, if the multi-screen service request command template includes information related to multi-screen service content, a playing terminal and playing time, then the user terminal 2 a edits, in the step S 27 , a multi-screen service request command including a requirement of the user on the multi-screen service content, the playing terminal and the playing time according to an input of the user. For example, a well edited multi-screen service request command based upon the OMA protocol can be represented in the form of a string of characters as {Mobile, 9:00, 20090615, NBA Final 2009 #5; PC, None; TV, 21:00, 20090615, NBA Final 2009 #5}, and this command indicates the user requests watching a live show of the 5 th round of NBA Finals, 2009 at 9:00 on his or her handheld portable terminal, i.e., the user terminal 2 a , and a video record of the same match on his or her television set at 21:00.
[0053] According to some embodiments of the invention, if the multi-screen service request command template further includes information related to a transmission priority of the multi-screen service, then the user terminal 2 a edits, in the step S 27 , a multi-screen service request command including a requirement of the user on the transmission priority of the multi-screen service according to an input of the user.
[0054] Then in the step S 29 , the user terminal 2 a transmits the well edited multi-screen service request command to the network device 1 .
[0055] According to an embodiment of the invention, the following step is further included between steps S 23 and S 27 : the user terminal 2 a provides, according to the acquired multi-screen service request command template, an input parameter-limited user interface for the user to edit the multi-screen service request command. Specifically, the user terminal 2 a can provide a more friendly input control interface according to the multi-screen service request command template, e.g., providing a dropdown menu, an input box, a temporarily pop-up help box attached thereto and the like, so that the user can complete the editing of the multi-screen service request command by means of simple operations such as inputting a number, selecting some options, etc. For example, when the multi-screen service request command template includes information related to multi-screen service content, a playing terminal, playing time and a playing date, a corresponding input control interface can associate the information related to the playing terminal and the service contents together and provide a plurality of combinations as indexed items, so that the user can just input into the fields of “Playing Time” and “Playing Date” for a desired specific item of “Playing Terminal+Service Content”. The description here of the input control interface is merely illustrative but not limitative.
[0056] FIG. 4 illustrates a block diagram of a collecting apparatus for collecting a multi-screen service request of a user in a network device of a communication network according to an embodiment of the invention. As illustrated in FIG. 4 , the collecting apparatus 10 includes first transmitting means 101 and first receiving means 102 . The collecting apparatus 10 is typically arranged in a network device in a communication network, e.g., the network device 1 .
[0057] FIG. 5 illustrates a block diagram of a requesting apparatus for requesting a multi-screen service in a handheld portable terminal of a communication network according to an embodiment of the invention. As illustrated in FIG. 5 , the requesting apparatus 20 includes second receiving means 201 , template acquiring means 202 , command editing means 203 and second transmitting means 204 . The requesting apparatus 20 is typically arranged in a handheld portable terminal of a communication network, e.g., the user terminal 2 a.
[0058] The invention will be set forth below from the perspective of a device with reference to FIG. 2 , FIG. 4 and FIG. 5 .
[0059] The following steps will be performed at the side of the network device 1 :
[0060] Firstly the first transmitting means 101 in the collecting apparatus 10 transmits an OMA interactive media document to the user terminal 2 a , i.e., the handheld portable terminal of the user, where the OMA interactive media document includes at least one set of media objects including a multi-screen service request command template.
[0061] A playing terminal of a multi-screen service can be a handheld portable terminal, a television set or a computer, and typically only the handheld portable terminal can be carried around with the user and on standby all the time, so transmitting the service request command template to the handheld portable terminal facilitates a timely feedback from the user.
[0062] Various mobile networks exist, and handheld portable terminals of the different mobile networks support different protocols. For compatibility with various systems, protocols and devices, the OMA interactive media document transmitted by the first transmitting means 101 can include a plurality of sets of media objects, each of which corresponds to a multi-screen service request command template based upon a specific protocol. For example but not limited thereto, a set of media objects can be a multi-screen service request command template based upon the OMA protocol or a multi-screen service request command template based upon the SMS protocol or a multi-screen service request command template based upon the SIP protocol or a link to a multi-screen service request command shortcut control page. Such link can be a link based upon the WAP protocol or a web link based upon the HTTP protocol.
[0063] As illustrated in FIG. 3 , the OMA interactive media document transmitted by the first transmitting means 101 preferably includes all the four sets of media objects, i.e., a multi-screen service request command template based upon the OMA protocol, a multi-screen service request command template based upon the SMS protocol, a multi-screen service request command template based upon the SIP protocol and a link to a multi-screen service request command shortcut control page. Of course the OMA interactive media document transmitted by the first transmitting means 101 can alternatively include two, three or even only one of the foregoing sets of media objects and can further include a multi-screen service request command template based upon another protocol. The user terminal 2 a can determine one of the multi-screen service request command templates according to its supported protocol, edit a multi-screen service request command according to the determined template and feed it back to the network device 1 .
[0064] The user receiving a multi-screen service is interested particularly in three W's (What, Where and When), i.e., multi-screen service content, a playing terminal and playing time. Therefore, the multi-screen service request command template preferably includes information related to the foregoing three items. Those skilled in the art shall appreciate that information related to the multi-screen service content, the playing terminal and the playing time can be in the form of a string of characters, a number or another identifier. For example, the three types of playing terminals can be identified in a string of characters respectively as “Mobile”, “PC” and “TV” or numerically respectively as “001”, “002” and “ 003 ”. Correspondingly the multi-screen service request command fed back from the user terminal 2 a further includes a requirement of the user on the multi-screen service content, the playing terminal and the playing time.
[0065] As described above, the multi-screen service request command template includes a number of elements, e.g., multi-screen service content, a playing terminal, playing time, etc. With the purpose of a uniform command format, an arrangement order of the respective elements shall be specified in the multi-screen service request command template. For example, a request command template in which a playing terminal, playing time, a playing date and service content are arranged in that order can be represented as {______, ______:______, yy/mm/dd, ______}; and the OMA interactive media document can further include the definitions of respective fields of the template and a guidance regarding how the user constructs his or her own request command. Alternatively the request command template can be an already well edited request command, and a part or all of the fields therein can be modified by the user as desired; for example, a request command template can be represented as {Mobile,9:00,20090615,NBA Final 2009 #5}, where the underlined fields can be modified by the user. The description for the format of the multi-screen service request command template herein is merely illustrative but not limiting.
[0066] Furthermore, the OMA interactive media document can further include multi-screen service notification information, which can include any one or more of the title of multi-screen service content, default playing time, a charging criterion, a charging mode and multimedia digest information of the multi-screen service content. For example, if an item of new multi-screen service content is a film, then multi-screen service notification information can include the title of the film and corresponding multimedia digest information including a brief literal introduction and/or a video clip of the film. The user can decide whether to receive the entire film by watching the brief literal introduction and/or the video clip of the film. In another example, an item of new multi-screen service content is an impending football match, then multi-screen service notification information can include the title of the football match, default playing time, a charging criterion, multimedia digest information, etc., where the default playing time is live show time of the football match, the charging criterion can charge the user differently dependent upon whether he or she watches a live show or a video record, and the multimedia digest information can include a brief literal introduction of the match and/or a historical video of two competing sides of the match. The user can decide whether to watch the match according to the multimedia digest information and decide whether to watch the live show or the video record according to the charging criterion. The quality of user experience can be enhanced greatly by adding the abundant notification information related to the multi-screen service into the OMA interactive media document transmitted to the handheld portable terminal of the user.
[0067] Different users have different preferences of multi-screen service content. For example, some users prefer to a sport program while some prefer to current political news. Furthermore different users possess different end devices, that is, possess different ranges of available playing terminals, for example, some users possess a handheld portable terminal and a television set, some users possess a handheld portable terminal and a computer, and some users possess all of a handheld portable terminal, a television set and a computer. Therefore, preferably, the collecting apparatus 10 further includes an interactive media document determining sub-means for determining the OMA interactive media document according to a subscription agreement of the user.
[0068] Specifically, the user can select the type of the multi-screen service he or she wishes to receive upon subscribing to the multi-screen service, and the interactive media document determining sub-means determines the multi-screen service notification information and the multi-screen service request command template in the OMA interactive media document to be transmitted to the user according to the subscription agreement of the user. Users can be grouped according to their different subscription requirements. For example but not limited thereto, users who have subscribed to a sport program are grouped together; and when there is new content of the sport program, the first transmitting means 101 multicasts, to handheld portable terminals of this group of users, an OMA interactive media document with multi-screen service notification information including information related to the new content of the sport program. Multi-screen service content with a very high attention rate can be set by default as being possibly received by all the users. For example, when there is content of a live show of an Olympic Games opening ceremony or a live show of the 60th anniversary of National Day, the first transmitting means 101 can broadcast, to handheld portable terminals of all the users, an OMA interactive media document with multi-screen service notification information including information related to the corresponding content. Of course the first transmitting means 101 can alternatively transmit individually, to a handheld portable terminal of a specific user, an OMA interactive media document with multi-screen service notification information including information related to content of a unique type of service to which the user subscribes.
[0069] Furthermore information related to a multi-screen service playing terminal in the multi-screen service request command template can include any one or more of identification information of a handheld portable terminal, identification information of a computer and identifier information of a television set. Specifically the user can select a range of available playing terminals for receiving the multi-screen service upon subscribing to the multi-screen service, and the interactive media document determining sub-means determines information related to a multi-screen service playing terminal in the multi-screen service request command template in the OMA interactive media document to be transmitted to the user according to the subscription agreement of the user. For example, a user possesses a handheld portable terminal and a computer, and the range of available playing terminals selected by him upon subscribing to the multi-screen service includes only a handheld portable terminal and a computer, and the first transmitting means 101 transmits, to the handheld portable terminal of the user, an OMA interactive media document with a multi-screen service request command template carrying information related to a playing terminal including identification information of the handheld portable terminal and identification information of the computer. In another feasible solution, the first transmitting means 101 transmits, to a handheld portable terminal of any user, an OMA interactive media document with a multi-screen service request command template carrying information related to a playing terminal including all the identification information of the three playing terminals, and the multi-screen service request command template further includes status information of the respective playing terminals so that the interactive media document determining sub-means sets part or all of the status information of the three playing terminals to “Available” and the other status information to “Unavailable” according to the subscription agreement of the user.
[0070] All of the foregoing scenarios in which the OMA interactive media document is determined according to the subscription agreement of the user are merely illustrative but not limitative of the invention, and those skilled in the art can make other variation or modifications in light of the foregoing description. Furthermore those skilled in the art shall appreciate that the subscription agreement of the user can be updated as required for the user. For example, the type of the multi-screen service and/or the range of available playing terminals can be updated.
[0071] According to an embodiment of the invention, the multi-screen service request command template in the OMA interactive media document transmitted to the handheld portable terminal of the user can further include information related to a transmission priority of the multi-screen service. Thus the user can be provided with selection for different qualities of service.
[0072] As described above, the set of media objects in the OMA interactive media document can include a link to a multi-screen service request command shortcut control page, which can be a link based upon the WAP protocol or a web link based upon the HTTP protocol. In the page to which the link points, information related to multi-screen service content, a playing terminal, playing time, etc. can be included, and a dropdown menu of options, an input box or another edition control can be set to thereby provide the user with an approach to request a multi-screen service more simply and conveniently. Furthermore, the page can further include multimedia digest information related to multi-screen service content to facilitate a selection by the user and improve the quality of user experience. The user can access a multi-screen service request command shortcut control page based upon the HTTP protocol and perform a corresponding operation such as inputting a number or selecting some options through the user terminal 2 c , i.e., the personal computer. In response to the input of the user, the edition control built in the page will automatically generate and transmit the multi-screen service request command to the network device 1 . Those skilled in the art shall appreciate that the network device 1 and a server for providing the multi-screen service request command shortcut control page can be the same device or devices independent of each other.
[0073] After the first transmitting means 101 transmits the OMA interactive media document carrying the multi-screen service request command template, the first receiving means 102 receives the multi-screen service request command fed back from the user and determines the requirement of the user on the multi-screen service according to the multi-screen service request command. As described above, the multi-screen service request command fed back from the user can come from the handheld portable terminal of the user, e.g., the user terminal 2 a , etc., or the server providing the multi-screen service request command shortcut control page.
[0074] Specifically, for example, the user terminal 2 a feeds back a multi-screen service request command based upon the OMA protocol with the content of {Mobile, 9:00, 20090615, NBA Final 2009 #5; PC, None; TV, 21:00, 20090615, NBA Final 2009 #5}, and the first receiving means 102 can determine, according to the request command, that: the user requests watching a live show of the 5 th round of NBA Finals, 2009 at 9:00 on his or her handheld portable terminal, i.e., the user terminal 2 a , and a video record of the same match on his or her television set at 21:00. Those skilled in the art shall appreciate that the foregoing form and content of the multi-screen service request command are merely illustrative but not limitative of the invention.
[0075] The following steps will be performed at the side of the user terminal 2 a , i.e., the handheld portable terminal of the user:
[0076] Firstly the second receiving means 201 receives the OMA interactive media document from the network device 1 , where the OMA interactive media document includes at least one set of media objects including a multi-screen service request command template.
[0077] As described above, the received OMA interactive media document preferably include four sets of media objects, which are a multi-screen service request command template based upon the OMA protocol, a multi-screen service request command template based upon the SMS protocol, a multi-screen service request command template based upon the SIP protocol and a link to a multi-screen service request command shortcut control page. respectively. Of course the received OMA interactive media document can alternatively include two, three or even only one of the foregoing sets of media objects and can further include a multi-screen service request command template based upon another protocol.
[0078] Then the template acquiring means 202 can acquire the multi-screen service request command template in the set of media objects according to a protocol supported by the user terminal 2 a.
[0079] Specifically, the protocol supported by the user terminal 2 a can include any one or more of the OMA protocol, the SMS protocol, the SIP protocol, the WAP protocol and the HTTP protocol.
[0080] In a very possible scenario, the OMA interactive media document received by the second receiving means 201 includes a plurality of sets of media objects, which are a multi-screen service request command template based upon the OMA protocol, a multi-screen service request command template based upon the SMS protocol, a multi-screen service request command template based upon the SIP protocol and a link to a multi-screen service request command shortcut control page based upon the WAP protocol and/or based upon the HTTP protocol, respectively. According to some embodiments of the invention, if the user terminal 2 a supports one or more of the foregoing protocols, e.g., the OMA protocol, the SMS protocol, the SIP protocol, the WAP protocol, etc., then the template acquiring means 202 can fetch a plurality of multi-screen service request command templates respectively based upon the different protocols. Preferably, the template acquiring means 202 will determine a multi-screen service request command template in a set of media objects corresponding to one of its supported protocols according to a predetermined rule. For different purposes, the predetermined rule here can be any one or more of the following: a transmission time for the multi-screen service request command based upon the determined protocol being the shortest; a bandwidth resource occupied by the multi-screen service request command based upon the determined protocol being the least. For example, the template acquiring means 202 can select the command template based upon the OMA protocol or the command template based upon the SIP protocol in order to achieve the least transmission time for the fed-back multi-screen service request command.
[0081] Then the command editing means 203 edits a multi-screen service request command based upon the acquired multi-screen service request command template according to an input of the user.
[0082] For example, the template acquiring means 202 has determined the multi-screen service request command template based upon the OMA protocol, and then the command editing means 203 edits a multi-screen service request command in compliance with the OMA protocol based upon the determined template according to an input of the user.
[0083] According to some embodiments of the invention, if the multi-screen service request command template includes information related to multi-screen service content, a playing terminal and playing time, then the command editing means 203 edits a multi-screen service request command including a requirement of the user on the multi-screen service content, the playing terminal and the playing time according to an input of the user. For example, a well edited multi-screen service request command based upon the OMA protocol can be represented in the form of a string of characters as {Mobile, 9:00, 20090615, NBA Final 2009 #5; PC, None; TV, 21:00, 20090615, NBA Final 2009 #5}, and this command indicates that the user requests watching a live show of the 5 th round of NBA Finals, 2009 at 9:00 on his or her handheld portable terminal, i.e., the user terminal 2 a , and a video record of the same match on his or her television set at 21:00.
[0084] According to some embodiments of the invention, if the multi-screen service request command template can further include information related to a transmission priority of the multi-screen service, then the command editing means 203 edits a multi-screen service request command including a requirement of the user on the transmission priority of the multi-screen service according to an input of the user.
[0085] Then the second transmitting means 204 transmits the well edited multi-screen service request command to the network device 1 .
[0086] According to an embodiment of the invention, the requesting apparatus 20 can further include user interface providing sub-means for providing, according to the multi-screen service request command template acquired by the template acquiring means 202 , an input parameter-limited user interface for the user to edit the multi-screen service request command. Specifically, the user interface providing sub-means can provide, according to the multi-screen service request command template, a more friendly input control interface, e.g. a dropdown menu, an input box, a temporarily pop-up help box attached thereto and the like, so that the user can edit the multi-screen service request command with simple operations such as inputting a number, selecting some options, etc. For example, if the multi-screen service request command template includes information related to multi-screen service content, a playing terminal, playing time and a playing date, then a corresponding input control interface can associate the information related to the playing terminal and the service contents together and provide a plurality of combinations as indexed items, so that the user can just input into the fields of “Playing Time” and “Playing Date” for a desired specific item of “Playing Terminal+Service Content”. The description here of the input control interface is merely illustrative but not limitative.
[0087] As described above, transmission of multi-screen service content can be performed by the network device 1 or another server mutually independent of the network device 1 .
[0088] By way of an example in which transmission of multi-screen service content is performed by the network device 1 , the network device 1 can provide a plurality of levels of quality of service according to the information related to the playing time and/or the information related to the transmission priority of the multi-screen service in the received multi-screen service request command fed back from the user, and an operator can also set various charging criteria accordingly. For example, a multi-screen service request command received by the network device 1 indicates that the user requests watching a live show of a sport match at 9:00 on his or her handheld portable terminal and a video record of the same match on his or her television set at 21:00. For a real time service like the live show, the network device 1 will provide in real time a higher bandwidth resource so as to start from 9:00 transmitting the content in real time to the handheld portable terminal of the user; and for a non-real time service like the video record, the network device 1 only needs to provide a bandwidth resource when the network is free so as to transmit the content to the television set of the user stating from some time prior to 21:00, thereby making full use of the bandwidth resource. Furthermore, a charging criterion can be associated with the transmission priority of a multi-screen service. A user with a higher charging criterion can be authorized to set a higher transmission priority in his or her multi-screen service request command, and the network device 1 will transmit preferentially the content requested in the multi-screen service request command in which the higher transmission priority is set.
[0089] Those skilled in the art shall appreciate the respective means as referred to in the invention can be implemented in a hardware module or in a functional module in software or in hardware module integrated with a software functional module.
[0090] The embodiments of the invention have been described above, but the invention will not be limited to any specific system, device or protocol and those skilled in the art can make numerous variations or modifications without departing from the scope of the appended claims.
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A uniform multi-screen service request command template is defined by using an OMA interactive media document so that a notification of a network device about a multi-screen service and a request command of a user for multi-screen service content are compatible with the OMA standard. With the multi-screen service request command template defined in the OMA interactive media document in the invention, the user can create a request command in the uniform format simply and rapidly to thereby greatly reduce the probability of an input error of the user. Furthermore, it is not necessary to set up a connection in advance, thus greatly shortening a delay and reducing the probability of an error and hence greatly improving a quality of experience of the user.
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This application is a continuation-in-part of Ser. No. 380,143, filed July 14, 1989, abandoned, which is incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates to coordination complexes of lanthanide metals. In one of its more particular aspects, it relates to a pentadienyllutetium complex.
BACKGROUND OF THE INVENTION
Hydrocarbyl complexes of the lanthanide metals complexes, such as LiLn(allyl) 4 ·dioxane (Ln=lanthanide), have been shown to catalyze the polymerization of 1,3-butadiene.
SUMMARY OF THE INVENTION
The present invention provides a novel complex of lutetium. This complex has the formula (η 5 --(CH 3 ) 2 C 5 H 5 )Lu(η 5 --,η 3 --(CH 3 ) C 5 H 5 CH 2 CH 2 CH(CH 3 )C 3 H 3 (CH 3 )). It is prepared by reaction of 2,4-dimethylpentadienylpotassium and lutetium trichloride. The complex may be useful as a diene polymerization catalyst.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a structural formula of the pentadienyllutetium complex of the present invention.
FIG. 2 is an ORTEP (Oak Ridge Thermal Ellipsoid Plot) diagram of the pentadienyllutetium complex of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The pentadienyllutetium complex of the present invention has the formula (η 5 --(CH 3 ) 2 C 5 H 5 )Lu(η 5 --,η 3 --(CH 3 ) C 5 H 5 CH 2 CH 2 CH(CH 3 )C 3 H 3 (CH 3 )). Its structural formula is shown in FIG. 1. From the structural formula it can be seen that a lutetium atom is η 5 -complexed with one solitary 2,4-dimethylpentadienyl ligand; the lutetium atom is also complexed with one 2,4-dimethylpentadienyl dimer via η 3 -allyl and η 5 -pentadienyl bonding.
The structure of the pentadienyllutetium complex of the present invention is further illustrated in the ORTEP diagram shown in FIG. 2, wherein each of the carbon atoms is numbered. An ORTEP diagram, derived from X-ray crystallographic data, shows the spatial relationships of the atoms within a molecule and indicates the probability of location of the atoms at a specific point in space by means of ellipsoids. The ORTEP plot is shown at the 30 percent probability level.
An unusual feature of the novel pentadienyllutetium complex of the present invention is that the lutetium atom is complexed by one 2,4-dimethylpentadienyl ligand as well as by one 2,4-dimethylpentadienyl dimer.
The pentadienyllutetium complex of the present invention is prepared by means of a metathesis reaction which involves the addition of three equivalents of 2,4-dimethylpentadienylpotassium to one equivalent of lutetium trichloride. Any organic solvent which is nonreactive with the reactants and in which the reactants are sufficiently soluble can be used, but an ether solvent such as tetrahydrofuran (THF) is preferred. The reaction is preferably carried out at low temperatures; for example, at temperatures in the range of about -40° C. to about -100° C.; a temperature of about -78° C. is especially preferred. Because of the acute air sensitivity and moisture sensitivity of the organometallic product of this reaction, it is desirable to conduct the metathesis reaction under an inert gas such as argon. Reaction times of about 1 hour to about 2 hours are effective. Work-up of the reaction product can be accomplished by allowing the reaction mixture to warm to room temperature, vacuum evaporating the solvent, extracting the residue with an inert solvent such as hexane, cyclohexane, or heptane, and concentrating the resulting extract. The concentrated extract yields a crystalline product upon cooling. The crystalline product has been found to have the formula (η 5 --(CH 3 ) 2 C 5 H 5 )Lu(η 5 --,η 3 --(CH 3 ) C 5 H 5 CH 2 CH 2 CH(CH 3 )C 3 H 3 (CH 3 )), the structural formula shown in FIG. 1 and the ORTEP diagram shown in FIG. 2.
The present invention will be better understood by reference to the following examples which are included for purposes of illustration and are not to be construed as in any way limiting the scope of the present invention, which is defined in the appended claims.
EXAMPLE 1
(η 5 --(CH 3 ) 2 C 5 H 5 )Lu(η 5 --,η 3 --(CH 3 ) C 5 H 5 CH 2 CH 2 CH(CH 3 )C 3 H 3 (CH 3 )).
Into a 100-mL, three-necked, round-bottom flask equipped with a spinbar, rubber septum, glass stopper and gas inlet was placed 1.50 g (5.33 mmol) of anhydrous lutetium trichloride and 20 mL of THF. Argon was introduced through the gas inlet. The assembly was attached to a Schlenk line and the solution was stirred overnight to disperse the undissolved salt. Into a 50-mL, single-necked, round-bottom flask was placed a solution containing 2.15 g (16.0 mmol) of 2,4-dimethylpentadienyl-potassium prepared according to the method of Yasuda, H.; Ohnuma, Y.; Yamauchi, M.; Tani, H.; Nakamura, A., Bull, Chem. Soc. Jpn. 1979, 52, 2036, in 30 mL of THF. The flask was stoppered with a rubber septum and removed to the Schlenk line. This light amber-colored solution was slowly syringed into the rapidly stirred slurry of lutetium trichloride, previously cooled to -78° C. Upon dropwise addition of the potassium salt solution, a localized yellow color appeared momentarily, then dissipated. This occurred until approximately 1 mL of solution had been added. The yellow color then remained as the balance of the potassium salt was added. After complete addition, the solution was stirred for an additional 1.5 hr. The cooling bath was then removed and the solution was allowed to warm slowly to room temperature. During this period the solution gradually turned dark brown. After stirring overnight, the solvent was vacuum evaporated. The residue was extracted with hexane (4×20 mL) and the resulting extract was concentrated to a volume of 30 mL. The solution was then cooled to -78° C. for 8 hr, which resulted in the formation of olive-colored crystals. These crystals were isolated and subsequently dissolved in a minimum amount of THF/hexane. The solution was cooled to ca. -30° C. overnight, resulting in the formation of pale orange-yellow crystals suitable for X-ray diffraction analysis; yield 0.13g (5.3%). IR (Nujol mull) absorptions were observed at 3110 (vw), 3090 (w), 3080 (w), 3025 (w), 1525 (s, br), 1425 (sh), 1350 (w), 1340 (w), 1320 (vw), 1290 (w), 1270 (w), 1250 (w-m), 1230 (w), 1210 (vw), 1180 (w), 1155 (vw), 1090 (w-m), 1060 (m), 1030 (m), 1015 (w), 990 (sh), 980 (w), 945 (w), 925 (w), 890 (w), 875 (w, br), 850 (w-m), 835 (w-m), 810 (s), 800 (w), 795 (w), 770 (s, br), 700 (sh), 690 (sh), 630 (m), 600 (w) and 565 (sh) cm -1 . Anal. Calcd for LuC 21 H 33 : Lu, 38.00%. Found: Lu, 37.8%.
EXAMPLE 2
NMR Spectra of (η 5 --(CH 3 ) 2 C 5 H 5 )Lu(η 5 --,η 3 --(CH 3 )C 5 H 5 CH 2 CH 2 CH(CH 3 )C 3 H 3 (CH 3 )).
1 H and 13 C NMR spectra were acquired at ambient temperature with an IBM AF-270 FT NMR narrow-bore spectrometer. All data processing was done on an Aspect-3000 computer using DISNMR standard software. A 5 mm dual tuned probe was used to observe 1 H and 13 C nuclei at 270.130 and 67.925 MHz, respectively. The 90° pulse widths for 1 H and 13 C were 8.6 and 4.6 μsecs, respectively, while the decoupler coil pulse length was measured to be 14.2 μsecs. The lutetium complex was dissolved in benzene-d 6 solvent in a 5 mm Wilmad glass NMR tube and the sample was sealed under vacuum. The chemical shifts are reported in ppm from TMS by setting the residual proton signal of the solvent at 7.15 ppm and the corresponding 13 C solvent resonance at 128.0 ppm. The chemical shifts are shown in Table I.
TABLE I______________________________________.sup.13 C{.sup.1 H} and .sup.1 H NMR solution spectra in benzene-d.sub.6for(C.sub.7 H.sub.11)Lu(C.sub.14 H.sub.22). Chemical ShiftsCarbon .sup.1 H (multiplicity,No. .sup.a, b Type .sup.13 C proton count)______________________________________ 1 CH.sub.2 81.1 3.68(s, 1H) 2.68(s, 1H) 2 C 147.3 -- 3 CH 90.0 4.73(s, 1H) 4 C 145.2 -- 5 CH.sub.2 82.2 4.35(s, 1H) 3.37(s, 1H) 6 CH.sub.3 30.0 1.86(s, 3H) 7 CH.sub.3 29.9 1.98(s, 3H) 8 CH.sub.2 59.5 1.95(m, 1H) 1.51(d, 1H, J=4.59Hz) 9 C 151.3 --10 CH 80.9 3.58(d, 1H, J=7.64Hz)11 CH 33.8 2.46(m, 1H)12 CH.sub.2 44.3 1.75(m, 1H) 1.25(m, 1H)13 CH.sub.2 41.5 2.73(m, 1H) 1.93(m, 1H)14 C 155.0 --15 CH 98.0 4.63(s, 1H)16 C 149.0 --17 CH.sub.3 27.7 1.82(s, 3H)18 CH.sub.3 24.2 2.23(s, 3H)19 CH.sub.3 24.0 1.07(d, 3H, J=6.63Hz)20 CH.sub.2 73.0 3.12(s, 1H) 3.01(s, 1H)21 CH.sub.2 76.0 2.95(s, 1H) 2.61(s, 1H)______________________________________ .sup.a refers to carbon numbering scheme shown in FIG. 2 .sup.b signal assignments for atoms 1 through 7 were made based on inference from a combination of 2D NMR experiments and Xray data
Carbon signal multiplicities were determined using the J-modulated spin echo pulse sequence. A 2D 1 H COSY spectrum was acquired using Jeener's two pulse sequence 90°-t1-45°-ACQ(t2), minimizing the diagonal peak intensities, according to Nagayama, K.; Kumar, A.; Wuthrich, K.; Ernst, R. R., J. Mac. Res. 1980, 40, 321. Thirty two scans were collected over a spectral width of 2,703 Hz for each of 256 time increments to give a matrix of 1024×1024 data points. The recycle delay used was 2 secs. The long range COSY experiment used the pulse sequence of Bax, A.; Freeman, R., J. Mag. Res. 1981, 44, 542, 90°-t1-Δ-45°-Δ-ACQ(t2), under the same conditions but with Δ set to 80 msecs to observe weak cross peaks from long range couplings. The free induction decays were multiplied with an unshifted sine squared bell function and symmetrization was applied to the final spectrum.
A 2D heteronuclear correlation spectrum (XHCORR) according to Bax, A.; Morris, G.; J. Mac. Res. 1981, 42, 501, was recorded using the pulse sequence, 90° (H)-1/2 t1-180° (C)-1/2t1-D3-90° (C)90° (H)d4-ACQ(t2/) (under proton decoupling). The acquisition involved 128 scans for each of 128 t1 increments using a 3 sec recycle delay. Delays D3 and D4 were optimized for J=160 Hz (i.e. set to 3.125 and 1.563 msec, respectively). The spectral widths used in the F1 and F2 domains were 2,702 and 13,514 Hz, respectively. The t2 data were exponentially weighed using a line-broadening factor of 5 Hz and Fourier transformed over 2,048 data points. The t1 interferograms were modified with a shifted (π/4) sine bell squared function before Fourier transformation over 256W data points as a magnitude spectrum. Finally, the pulse sequence that worked best for obtaining a long range heteronuclear correlation spectrum of this organometallic complex was the modified version of XHCORR suggested in Krishnamurthy, V. V.; Nunlist, R., J. Mac. Res. 1988, 80, 280. The sequence involves the elimination of the refocusing D4 delay and BB decoupling during acquisition. The D3 delay was optimized for long range couplings of the magnitude of 8 Hz and set to be 62.5 msec. The number of scans was increased to 512 for each increment of t1.
EXAMPLE 3
X-ray Crystallography of (η 5 --(CH 3 ) 2 C 5 H 5 )Lu(η 5 --,η 3 --(CH 3 )C 5 H 5 CH 2 CH 2 CH(CH 3 )C 3 H 3 (CH 3 )).
A single crystal of approximate dimensions 0.20×0.30×0.40 mm was sealed into a thin-walled glass capillary under an inert atmosphere (N 2 ) and mounted on a Syntex P2 1 diffractometer. Subsequent setup operations (determination of accurate unit cell dimensions and orientation matrix) and collection of room temperature (296 K) intensity data were carried out using standard techniques similar to those of Churchill, M. R.; Lashewycz, R. A.; Rotella, F. J., Inorg. Chem. 1977, 16, 265. Details appear in Table II.
TABLE II______________________________________Crystal Data and Structure Refinement Parameters for(C.sub.7 H.sub.11)Lu(C.sub.14 H.sub.22).______________________________________Formula: C.sub.21 H.sub.33 LuFw: 460.5Crystal System: TriclinicSpace Group: P1a = 7.382(4) Åb = 8.703(2) Åc = 16.443(6) Åα = 78.54(2)°β = 84.74(4)°γ = 68.11(3)°V = 960.5(6) Å.sup.3Z = 2D.sub.calcd, Mg/m.sup.3 = 1.592Diffractometer: Syntex P2.sub.1Radiation: MoKα (.sup.-- λ = 0.710730 Å)Monochromator: Highly oriented graphiteData Collected: +h, ±GK,±1Scan Type: θ-2θScan Width: 1.2 deg.Scan Speed: 2.0 deg min.sup.-1 (in ω)2θ.sub.max, deg: 55.0μ(Mo Kα), mm.sup.-1 = 5.144Absorption correction: Semi-Empirical (ψ-scanmethod)Reflections Collected: 4439Reflections with |F.sub.o | > 0: 4380No. of Variables: 200R.sub.F = 3.3%; R.sub.wF = 4.8%Goodness of Fit: 1.23______________________________________
All 4439 data were corrected for the effects of absorption and for Lorentz and polarization effects and placed on an approximately absolute scale by means of a Wilson plot. Any reflection with I(net)<0 was assigned the value |F o |=0. A careful examination of a preliminary data set revealed no systematic extinctions nor any diffraction symmetry other than the Friedel condition. The centrosymmetric triclinic space group P1[C 1 i ; No. 2] was chosen and later determined to be correct by successful solution of the structure.
All crystallographic calculations were carried out using either our locally modified version of the UCLA Crystallographic Computing Package (UCLA Crystallographic Computing Package, University of California Los Angeles, 1981, C. Strouse; personal communication) or the SHELXTL PLUS program set (Nicolet Instrument Corporation; Madison, WI 1988). The analytical scattering factors for neutral atoms were used throughout the analysis (International Tables for X-Ray Crystallography; Kynoch Press: Birmingham, England, 1974; pp 99-101); both the real (Δf') and imaginary (iΔf") components of anomalous dispersion (International Tables for X-Ray Crystallography; Kynoch Press: Birmingham, England, 1974; pp 149-150) were included. The quantity minimized during least-squares analysis was Σw(|F o |-|F c |) 2 where w -1 =σ 2 (|F o |)+0.0007(|F o |) 2 .
The structure was solved by direct methods (MITHRIL) (Gilmore, C. J., J. Appl. Cryst. 1984, 17, 4246.) and refined by full-matrix least-squares techniques (SHELXTL). Hydrogen atom contributions were included using a riding model with d(C-H)=0.96Å and U(iso)=0.08Å 2 . Refinement of positional and anisotropic thermal parameters led to convergence with R F =3.3%; R wF =4.8% and GOF=1.23 for 200 variables refined against all 4380 unique data, (R F =3.1; R wF =4.6 for those 4185 data with |F o |>6.0 σ(|F o |)). A final difference-Fourier map was devoid of significant features, ρ (max)=1.37eÅ -3 .
Atomic coordinates and equivalent isotropic displacement coefficients are listed in Table III. Selected interatomic distances and angles are listed in Table IV. Anisotropic displacement coefficients are shown in Table V while H-atom coordinates and isotropic displacement coefficients are shown in Table VI.
TABLE III______________________________________Atomic coordinates (×10.sup.4) and equivalent isotropicdisplacement coefficients (Å.sup.2 × 10.sup.4) for (C.sub.7H.sub.11)Lu(C.sub.14 H.sub.22)x y z U(eq)*______________________________________Lu(1) -2242.5(.2) 347.4(.2) 2205.9(.1) 273.5(.9)C(1) 361(9) -1464(7) 3336(3) 549(21)C(2) -164(7) -2687(6) 3091(3) 469(17)C(3) -167(7) -2961(6) 2291(3) 406(15)C(4) 481(7) -2203(6) 1517(3) 448(16)C(5) 1181(8) -921(8) 1419(4) 603(22)C(6) -974(10) -3737(7) 3761(4) 741(24)C(7) 256(10) -2858(8) 771(4) 657(24)C(8) -1403(7) 2854(6) 1785(3) 454(17)C(9) -2849(7) 3468(5) 2387(3) 376(15)C(10) -2798(7) 2535(6) 3187(3) 434(17)C(11) -4231(10) 3020(8) 3887(3) 558(23)C(12) -5561(10) 1993(9) 4090(3) 607(25)C(13) -6885(8) 2158(8) 3381(3) 553(21)C(14) -5909(6) 1106(6) 2721(3) 402(16)C(15) -5981(6) 2044(5) 1896(3) 374(14)C(16) -5152(6) 1483(6) 1143(3) 385(15)C(17) -5375(9) 2847(7) 391(3) 557(21)C(18) -4531(9) 5100(6) 2112(3) 509(19)C(19) -3045(14) 2756(12) 4668(4) 951(47)C(20) -4972(7) -585(6) 2951(3) 444(17)C(21) -4058(7) -142(6) 1046(3) 450(17)______________________________________ *Equivalent isotropic U defined as one third of the trace of the orthogonalized U.sub.ij tensor
TABLE IV______________________________________Selected Interatomic Distances (Å) and Angles(Deg) for (C.sub.7 H.sub.11)Lu(C.sub.14 H.sub.22).______________________________________Interatomic DistancesLu(1)-C(1) 2.620(6) Lu(1)-C(2) 2.703(4)Lu(1)-C(3) 2.693(4) Lu(1)-C(4) 2.740(5)Lu(1)-C(5) 2.677(6) Lu(1)-C(8) 2.440(6)Lu(1)-C(9) 2.656(5) Lu(1)-C(10) 2.629(5)Lu(1)-C(14) 2.636(5) Lu(1)-C(15) 2.642(4)Lu(1)-C(16) 2.658(5) Lu(1)-C(20) 2.567(5)Lu(1)-C(21) 2.614(6) Lu(1)-Cent(1) 2.227Lu(1)-Cent(2) 2.353 Lu(1)-Cent(3) 2.149C(1)-C(2) 1.398(10) C(2)-C(3) 1.383(8)C(2)-C(6) 1.514(9) C(3)-C(4) 1.439(7)C(4)-C(5) 1.371(10) C(4)-C(7) 1.497(9)C(8)-C(9) 1.412(6) C(9)-C(10) 1.398(6)C(9)-C(18) 1.515(6) C(10)-C(11) 1.504(7)C(11)-C(12) 1.533(12) C(11)-C(19) 1.551(11)C(12)-C(13) 1.541(9) C(13)-C(14) 1.515(8)C(14)-C(15) 1.432(6) C(14)-C(20) 1.362(7)C(15)-C(16) 1.423(7) C(16)-C(17) 1.508(7)C(16)-C(21) 1.376(6)Interatomic AnglesC(1)-C(2)-C(3) 127.1(5) C(1)-C(2)-C(6) 116.7(5)C(3)-C(2)-C(6) 116.0(6) C(2)-C(3)-C(4) 130.8(5)C(3)-C(4)-C(5) 125.4(5) C(3)-C(4)-C(7) 115.0(6)C(5)-C(4)-C(7) 119.6(5) C(8)-C(9)-C(10) 120.9(4)C(8)-C(9)-C(18) 117.5(4) C(10)-C(9)-C(18) 121.5(4)C(9)-C(10)-C(11) 126.8(4) C(10)-C(11)-C(12) 113.8(6)C(10)-C(11)-C(19) 107.6(6) C(12)-C(11)-C(19) 108.8(5)C(11)-C(12)-C(13) 115.2(5) C(12)-C(13)-C(14) 115.5(4)C(13)-C(14)-C(15) 114.8(4) C(13)-C(14)-C(20) 119.2(5)C(15)-C(14)-C(20) 125.8(5) C(14)-C(15)-C(16) 129.8(4)C(15)-C(16)-C(17) 115.7(4) C(15)-C(16)-C(21) 126.9(4)C(17)-C(16)-C(21) 117.3(4)Cent(1)-Lu(1)-Cent(2) 126.7 Cent(1)-Lu(1)- 128.9 Cent(3)Cent(2)-Lu(1)-Cent(3) 104.2______________________________________ Cent(1) is the centroid of the unit defined by C(1)C(2)-C(3)-C(4)-C(5). Cent(2) is the centroid of the unit defined by C(8)C(9)-C(10). Cent(3) is the centroid of the unit defined by C(20)C(14)-C(15)-C(16)-C(21).
TABLE V__________________________________________________________________________Anisotropic displacement coefficients (Å.sup.2 × 10.sup.4) for(C.sub.7 H.sub.11)Lu(C.sub.14 H.sub.22).U.sub.11 U.sub.22 U.sub.33 U.sub.23 U.sub.13 U.sub.12__________________________________________________________________________LU(1)205(1) 269(1) 337(1) -39(1) 22(1) -79(1)C(1) 528(31) 524(30) 506(27) -7(23) -213(23) -85(24)C(2) 392(24) 387(23) 496(25) -31(19) -15(19) -15(19)C(3) 343(21) 316(20) 495(23) -56(17) -16(17) -54(17)C(4) 322(22) 423(25) 441(23) -44(19) -3(18) 27(18)C(5) 341(25) 608(33) 668(34) -4(26) 158(23) -47(23)C(6) 788(42) 420(27) 617(33) 204(24) 167(30) 41(27)C(7) 681(39) 515(32) 568(32) -191(25) 99(28) 40(28)C(8) 417(24) 395(23) 594(27) -59(20) 31(20) -222(20)C(9) 449(23) 269(18) 474(22) -31(16) -84(18) -202(17)C(10)484(26) 423(23) 425(21) -60(18) -109(18) -195(20)C(11)775(40) 545(31) 371(23) -111(21) -44(23) -238(29)C(12)700(39) 718(38) 401(24) -181(24) 167(24) -256(31)C(13)403(26) 644(32) 586(29) -183(25) 139(22) -159(23)C(14)230(18) 464(24) 531(25) -132(20) 40(17) -136(17)C(15)280(19) 351(20) 477(22) -80(17) -39(16) -88(16)C(16)291(20) 385(22) 475(22) -92(18) -99(16) -91(17)C(17)634(33) 451(27) 503(26) -16(21) -148(23) -104(24)C(18)641(32) 319(21) 544(27) -65(19) -68(23) -141(21)C(19)1536(84) 1156(64) 462(31) -196(36) -171(40) -773(64)C(20)355(22) 454(24) 548(25) -36(19) 40(18) -213(19)C(21)411(24) 436(24) 507(24) -158(19) -75(19) -103(19)__________________________________________________________________________ The anisotropic displacement exponent takes the form: -2π.sup.2 (h.sup.2 a*.sup.2 U.sub.11 + . . . + 2hka*b*U.sub.12)
TABLE VI______________________________________H-Atom Coordinates (33 10.sup.4) and Isotropic Displacementcoefficients (A.sup.2 × 10.sup.4) for (C.sub.7 H.sub.11)Lu(C.sub.14H.sub.22). x y z U______________________________________H(1A) 7 -1272 3894 800H(1B) 1675 -1537 3187 800H(3A) -918 -3620 2223 800H(5A) 2316 -1146 1733 800H(5B) 1268 -375 857 800H(6A) 65 -4757 3979 800H(6B) -1563 -3119 4199 800H(6C) -1938 -4006 3525 800H(7A) 1440 -3754 664 800H(7B) -797 -3270 871 800H(7C) -31 -1961 300 800H(8A) -1723 3425 1225 800H(8B) -104 2708 1920 800H(10A) -1540 2316 3399 800H(11A) -5044 4187 3747 800H(12A) -6345 2293 4574 800H(12B) -4731 831 4226 800H(13A) -7399 3321 3121 800H(13B) -7966 1851 3619 800H(15A) -6392 3239 1863 800H(17A) -6532 3036 101 800H(17B) -5480 3864 568 800H(17C) -4257 2517 28 800H(18A) - 4300 6011 2274 800H(18B) -4639 5301 1520 800H(18C) -5720 5020 2371 800H(19A) -3937 3059 5123 800H(19B) -2215 1593 4802 800H(19C) -2261 3443 4567 800H(20A) -4829 -987 3538 800H(20B) -5381 -1274 2677 800H(21A) -4677 -950 1221 800H(21B) -3364 -267 525 800______________________________________
The invention may be embodied in other forms without departing from the spirit or essential characteristics thereof. Consequently, the present embodiments and examples are to be considered only as being illustrative and not restrictive, with the scope of the invention being defined by the appended claims. All embodiments which come within the scope and equivalency of the claims are therefore intended to be embraced therein.
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A pentadienyllutetium complex is prepared by reacting a source of 2,4-dimethylpentadienyl anions with a source of trivalent lutetium cations.
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TECHNICAL FIELD
[0001] The present invention relates to a semiconductor sensor device and more specifically relates to a MEMS (Micro Electro Mechanical Systems) device into which structures are sealed in an airtight manner such as an inertial sensor such as an acceleration or angular velocity sensor measuring a motion state of a moving body such as a vehicle, an airplane, a robot, a mobile phone, and a video camera, and a vibrator for generating filters and clocks.
BACKGROUND ART
[0002] In recent years, for the purpose of prevention of hand shake of a digital camera, posture control for an automobile and a robot, and the like, a sensor including a vibrator using a MEMS technique has widely been used.
[0003] In general, the vibrator of this kind is formed by processing a semiconductor substrate such as a silicon substrate with use of the MEMS technique such as etching and is sealed in an airtight manner by attaching another substrate to the semiconductor substrate under a preset atmosphere and pressure environment. For example, JP 5298047 B2 (PTL 1) describes an angular velocity sensor chip and an acceleration sensor chip sealed in an airtight manner.
[0004] Also, as a package structure for the sensor chip, a plastic package attracts attention. The plastic package has higher mass productivity than a conventional ceramic package and is an efficient package structure to decrease manufacturing cost of the sensor. For example, JP 10-148642 A (PTL 2) describes an acceleration sensor using a plastic package.
CITATION LIST
Patent Literature
[0005] PTL 1: JP 5298047 B2
[0006] PTL 1: JP 10-148642 A
SUMMARY OF INVENTION
Technical Problem
[0007] According to the aforementioned conventional technique, the vibrator in the sensor chip is sealed in an airtight manner in a cavity formed between the attached substrates. Also, the inside of the cavity is in an atmospheric pressure or vacuum state. In a case of plastic-packaging such a sensor chip by means of a transfer mold process, high pressure is applied to the sensor chip when plastic is filled in the mold with as high pressure as 5 to 20 MPa or so. At this time, since a pressure difference between the inside and the outside of the sensor chip increases, the cavity of the sensor chip is deformed. In a case in which stress that is equal to or higher than breaking stress of a material constituting the cavity is applied to the cavity, the cavity will break, and airtightness in the cavity will be lost. Also, in a case in which the entire cavity is depressed in a direction toward the vibrator, the vibrator may break together.
[0008] The relationship between stress o and pressure P is expressed by Equation 1 . To improve withstanding pressure of a cavity upper part, it is apparent that the substrate at the cavity upper part needs to be thickened. The maximum stress at this time is applied to an end portion of a cavity longer side, and the cavity breaks at the portion against the withstanding pressure.
[0000] h 2 =αPa 2 /σ (Equation 1)
[0000] In the equation, h is a thickness of the substrate at the cavity upper part, a is a length of a cavity shorter side, and α is a coefficient.
[0009] However, in a case in which an electric signal is to be input/output between the vibrator and an outside of the sensor chip, the electric connection with the outside of the sensor chip is sometimes established by means of wire bonding by forming a through interconnection in a vertical direction of a substrate forming the cavity and providing the cavity upper part with a pad for the wire bonding. At this time, to form the through interconnection, the substrate is etched in the vertical direction, the etched sidewall is electrically isolated by an isolator, and a conductive member is buried. In a case in which the substrate at the cavity upper part is thickened to improve withstanding pressure of the cavity upper part, the burying performance of the conductive member will be degraded, and the airtightness will be degraded. Also, resistance Rv of the through interconnection expressed in Equation 2 will increase. Consequently, a thermal noise Vn expressed in Equation 3 will increase, and the sensor performance will be lowered. In consideration of these problems, it is not easy to thicken the substrate at the cavity upper part.
[0000] Rv=μt/A (Equation 2)
[0000] In the equation, t is a length of the through interconnection, A is a cross-sectional area of the through interconnection, and ρ is resistivity of the conductive member.
[0000] Vn =√(4 kt ( Rv+Rs ) B ) (Equation 3)
[0000] In the equation, k is a Boltzmann coefficient, B is a bandwidth of a signal, T is an absolute temperature, and Rs is interconnection resistance in a horizontal direction of the cavity substrate.
[0010] An object of the present invention is to improve withstanding pressure of a cavity without degrading burying performance of a conductive member in a semiconductor sensor device using a plastic package.
Solution to Problem
[0011] To solve the above problem, in a semiconductor sensor device according to the present invention, a suspension substrate is attached directly on a cavity substrate into a structure in which a cavity upper part is suspended by the suspension substrate. Thus, the thickness h of the cavity upper part expressed in Equation 1 appears to increase as much as the thickness of the suspension substrate. Also, a substrate at the cavity upper part does not need to be thickened, and a length of a through interconnection does not need to increase. As a result, withstanding pressure P of the cavity upper part can be improved.
Advantageous Effects of Invention
[0012] According to the present invention, by suspending a cavity upper part with use of a suspension substrate, withstanding pressure of the cavity can be improved without degrading burying performance of a conductive member.
BRIEF DESCRIPTION OF DRAWINGS
[0013] FIG. 1 is a plan view of an acceleration sensor chip according to a first embodiment of the present invention.
[0014] FIG. 2 is a cross-sectional view along II-II in FIG. 1 .
[0015] FIG. 3 is a cross-sectional view along III-III in FIG. 1 .
[0016] FIG. 4 is a plan view illustrating the IV-IV cross-section in FIG. 2 .
[0017] FIG. 5 is a plan view illustrating the V-V cross-section in FIG. 2 .
[0018] FIG. 6 is a cross-sectional view of a chip package of the acceleration sensor chip according to the first embodiment of the present invention.
[0019] FIG. 7 is a plan view of the acceleration sensor chip according to a second embodiment of the present invention.
[0020] FIG. 8 is a plan view of the acceleration sensor chip according to a third embodiment of the present invention.
[0021] FIG. 9 is a plan view of an angular velocity sensor chip according to a fourth embodiment of the present invention.
[0022] FIG. 10 is a cross-sectional view along X-X in FIG. 9 .
[0023] FIG. 11 is a cross-sectional view along XI-XI in FIG. 9 .
[0024] FIG. 12 is a plan view illustrating the XII-XII cross-section in FIG. 10 .
[0025] FIG. 13 is a plan view illustrating the XIII-XIII cross-section in FIG. 10 .
[0026] FIG. 14 is a plan view of the acceleration sensor chip according to a fifth embodiment of the present invention.
DESCRIPTION OF EMBODIMENTS
[0027] In the following embodiments, description will be provided by dividing the content into plural sections or embodiments as needed for convenience. However, these are not irrelevant to each other but have a relationship in which one is partially or entirely a modification example, a detail, a supplemental explanation, or the like of another unless otherwise stated.
[0028] Also, in the following embodiments, in a case in which the number (such as number, value, amount, and range) or the like of elements is stated, the number is not limited to the specified number but may be equal to, more than, or less than the specified number unless otherwise stated and unless it is apparent that the number is limited to the specified number in principle.
[0029] Further, in the following embodiments, it is to be understood that components (including component steps) thereof are not necessarily essential unless otherwise stated and unless it is apparent that the components are essential in principle.
[0030] Similarly, in the following embodiments, in a case in which a shape, a positional relationship, and the like of components are stated, the shape and the like shall include those approximate or similar to these unless otherwise stated and unless the shape and the like do not seem to include those approximate or similar to these in principle. The same is true of the aforementioned number and range.
[0031] Also, in the figures for describing the embodiments, similar components are shown with the same reference numerals, and description of the duplicate components is omitted. Also, to facilitate understanding of the figures, even a plan view may be hatched.
First Embodiment
[0032] In the present embodiment, the present invention will be described using a MEMS-type acceleration sensor. In particular, an example of using a capacitive sensing acceleration sensor as the MEMS-type acceleration sensor will be described.
[0033] FIG. 1 is a plan view (upper view) of an acceleration sensor chip according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view along II-II in FIG. 1 . FIG. 3 is a cross-sectional view along III-III in FIG. 1 . FIG. 4 is a plan view illustrating the IV-IV cross-section in FIG. 2 . FIG. 5 is a plan view illustrating the V-V cross-section in FIG. 2 . FIG. 6 is a cross-sectional view of a chip package 19 of an acceleration sensor chip 11 according to the first embodiment of the present invention.
[0034] The acceleration sensor according to the present embodiment includes a cavity substrate 1 forming a cavity 1 a therein, a device substrate 4 forming a vibrator (weight) 4 a therein, a support substrate 5 supporting the vibrator, and a suspension substrate 2 suspending a cavity upper part 1 b of the cavity substrate 1 .
[0035] In forming the vibrator, the device substrate 4 made of monocrystalline silicon and the support substrate 5 made of monocrystalline silicon or glass are first attached to each other via an insulating film 6 . At this time, the support substrate 5 may or may not be provided with a cavity 5 a in advance. Subsequently, the substrate assembly into which the device substrate 4 and the support substrate 5 are attached is subject to photolithography and DRIE (Deep Reactive Ion Etching) to process the device substrate 4 and the insulating film 6 , to form the vibrator 4 a.
[0036] As illustrated in FIG. 4 , to the weight 4 a, serving as the vibrator, formed on the device substrate 4 , support beams 4 b are connected in a direction perpendicular to a vibrating direction of the weight 4 a. The other ends of these support beams 4 b are respectively connected to anchors 4 c provided in the direction perpendicular to the vibrating direction. At this time, since the anchors 4 c are fixed to the support substrate 5 via the insulating film 6 , the weight 4 a can vibrate in a Y-axial direction. Also, some of the anchors 4 c can electrically be connected to a below-mentioned through interconnection 7 similarly to an anchor 4 d and are used to electrically connect the weight 4 a to an external circuit.
[0037] Comb-like detection electrodes 4 e formed on the device substrate 4 are formed outside the weight 4 a. Comb-like fixed electrodes 4 f are formed on the device substrate 4 and the insulating film 6 to face the comb-like detection electrodes 4 e and are fixed to the support substrate 5 . That is, the detection electrodes 4 e are provided to project from an outer circumference of the weight 4 a in an extending direction of the support beams 4 b. Although only one detection electrode 4 e is drawn in FIG. 4 , the plurality of detection electrodes 4 e are provided in a comb-like shape. Also, the fixed electrodes 4 f receiving the comb-like detection electrodes 4 e are provided in a comb-like shape to correspond to the number of the detection electrodes 4 e.
[0038] As expressed in Equation 4, capacitance C is derived by a distance d between the detection electrode 4 e and the fixed electrode 4 f, a facing area A, dielectric constant E, and a facing number n between the electrodes 4 e and 4 f.
[0000] C=εAn/d (Equation 4)
[0000] When acceleration is applied to the vibrator in the y direction, the weight 4 a serving as a movable body is displaced in the y direction, and a displacement amount Δy between the electrodes at this time is a capacitance change ΔC.
[0039] Next, the cavity substrate 1 will be described. The cavity substrate 1 is made of monocrystalline silicon and is provided with a plurality of through holes for the cavity and the through interconnection 7 with use of photolithography and DRIE. The through interconnection 7 is formed by covering a sidewall of the through hole with an insulating film 8 and burying low-resistance silicon or a metal material therein. On an opposite surface of the surface provided with the cavity 1 a , a planar interconnection 9 is formed as illustrated in FIG. 5 . The planar interconnection 9 electrically connects a pad 9 a arranged further outside than an outer circumference of the cavity 1 a to the through interconnection 7 and is covered with an insulating film 10 except a pad opening portion 10 a for protection against corrosion caused by damage and moisture.
[0040] By attaching the cavity substrate 1 configured as above to the device substrate 4 , the detection electrode 4 e and the fixed electrode 4 f formed on the device substrate are electrically connected to the pad 9 a on the upper surface of the cavity substrate 1 via the through interconnection 7 and the planar interconnection 9 . At the time of attachment, the substrates are sealed in an airtight manner in atmospheric pressure or in a vacuum to obtain an effect of damping.
[0041] Subsequently, the suspension substrate 2 is mounted on the cavity upper part (cavity upper wall) 1 b of the cavity substrate 1 . At this time, the suspension substrate 2 is provided to cover a range from a position directly on the cavity 1 a to an outside of an outer circumference of the cavity upper part 1 b ( 1 ba , 1 bb ). At this time, the suspension substrate 2 is provided to cover an upper side of the through interconnection 7 as illustrated in FIG. 2 . Also, the thickness of the suspension substrate 2 is set so that withstanding pressure of the cavity upper part 1 b may be higher than pressure at the time of below-mentioned plastic sealing as expressed in Equation 1 shown above. In mounting the suspension substrate 2 , the suspension substrate 2 is attached via adhesive 3 such as DAF (Die Attach Film), epoxy, and silicon since a material for the suspension substrate 2 is assumed to be silicon or glass in FIGS. 2 and 3 . In a case in which the material for the suspension substrate 2 is plastic, the plastic itself functions as adhesive, and the adhesive 3 can be dispensed with. In other words, the suspension substrate 2 is connected to the cavity substrate 1 by the adhesive or the plastic. Meanwhile, as described above, the insulating films 8 and 10 or the like are provided between the suspension substrate 2 and the cavity substrate 1 as needed.
[0042] The acceleration sensor chip 11 configured as above is assembled into the chip package 19 as illustrated in FIG. 6 . The acceleration sensor chip 11 is implemented on a circuit board 12 via adhesive 13 and is electrically connected to the circuit board 13 by wire bonding 14 . The circuit board 13 is implemented on a lead frame 15 via adhesive 16 and is electrically connected to the lead frame 15 by wire bonding 17 . These are then sealed in plastic 18 into the chip package 19 . At this time, the plastic 18 seals the entirety of the acceleration sensor chip 11 to cover the upper part of the suspension substrate 2 as illustrated in FIG. 6 . In the plastic packaging by means of a transfer mold process, the sensor chip 11 is under a high-pressure environment as described above. However, since the cavity upper part 1 b is suspended by the suspension substrate 2 , withstanding pressure of the cavity upper part is higher than pressure at the time of the plastic sealing, and breakage of the cavity can be prevented.
[0043] A semiconductor sensor device according to the present embodiment includes the airtight cavity 1 a in a laminated structure into which the plurality of substrates 1 , 4 , and 5 are laminated and has a structure in which an outside of the laminated structure is covered with the plastic 18 . At an outside of the upper wall 1 b of the cavity 1 a is arranged the suspension substrate (plate-like member) 2 in which a length of at least one side thereof is longer than a length of a side of the cavity 1 a residing along the side, and the plate-like member 2 mechanically suspends the upper wall 1 b of the cavity 1 a.
[0044] In the plate-like member 2 , an opposite surface thereof of a surface thereof suspending the cavity upper wall 1 b is covered with the plastic 18 . Higher pressure than atmospheric pressure is applied to an outside of a part suspended by the plate-like member 2 on a surface suspended by the plate-like member 2 .
[0045] In the present embodiment, the substrate (cavity substrate) 1 suspended by the plate-like member 2 includes the through electrode 7 provided at the part suspended by the plate-like member 2 and passing through the substrate 1 in a thickness direction, the pad 9 a for wire bonding provided outside the part suspended by the plate-like member 2 , and the interconnection (planar interconnection) 9 electrically connected to the through electrode 7 , extracted outside the part suspended by the plate-like member 2 , and electrically connected to the pad 9 a. The planar interconnection 9 is made of metal or silicon.
[0046] In the present embodiment, the through interconnection 7 is provided to pass through the cavity substrate 1 , and the suspension substrate 2 is provided to cover an upper side of the through interconnection 7 . Thus, the through length of the through interconnection 7 will not be long, which can prevent burying performance of a conductive member for the through interconnection 7 from being degraded. The through interconnection 7 is electrically connected to the pad 9 a arranged outside the suspension substrate 2 by the planar interconnection 9 .
Second Embodiment
[0047] Next, a modification example of FIG. 1 will be described with reference to FIG. 7 . FIG. 7 is a plan view of the acceleration sensor chip 11 according to a second embodiment of the present invention. It is to be noted that detailed description of similar components to those in FIG. 1 will be omitted, and different points will mainly be described below.
[0048] In the present embodiment, in a suspension substrate 2 a suspending the cavity upper part 1 b illustrated in FIG. 7 , a length of a shorter side 2 aa of the suspension substrate 2 a is a length generating in the cavity substrate upper part 1 b an area 1 c not suspended by the suspension substrate 2 a. That is, in the present embodiment, the cavity 1 a is formed in a rectangular shape in which one side (two opposed sides) is a longer side while a side perpendicular to this longer side is a shorter side. Also, the suspension substrate (plate-like member) 2 is formed in a rectangular shape in which one side (two opposed sides) is a longer side while a side perpendicular to this longer side is a shorter side. The length of the shorter side of the suspension substrate 2 is a length that is shorter than the shorter side of the cavity and that causes a part of the cavity in the shorter-side direction not to be suspended. Meanwhile, although two areas 1 c in the cavity substrate upper part 1 b not suspended by the suspension substrate 2 a are provided in FIG. 7 , one area 1 c may be provided on either side of the suspension substrate 2 a.
[0049] Accordingly, as expressed in Equation 1 shown above, the length a of the shorter side 1 ba of the cavity upper part 1 b decreases, which brings about an effect of an increase in the withstanding pressure P of the cavity upper part. Also, since the longer side 1 bb in the cavity upper part 1 b of the cavity substrate 1 , to which the maximum stress is applied, is included in the area 1 c, one can easily determine whether or not the cavity upper part 1 b breaks against the withstanding pressure by observing the area 1 c.
[0050] In the present embodiment, the through interconnection 7 may be arranged in the area 1 c not suspended by the suspension substrate 2 . In this case, the through interconnection 7 can be configured not to be covered with the suspension substrate 2 .
Third Embodiment
[0051] Next, a modification example of FIG. 1 will be described with reference to FIG. 8 . FIG. 8 is a plan view of the acceleration sensor chip 11 according to a third embodiment of the present invention. It is to be noted that detailed description of similar components to those in FIG. 1 will be omitted, and different points will mainly be described below.
[0052] In the present embodiment, a plurality of suspension substrates 2 c suspending the cavity upper part 1 b are provided as illustrated in FIG. 8 . Meanwhile, although the number of the suspension substrates 2 c illustrated in FIG. 4 is two, the number may be two or more. Also, although one area 1 c in the cavity upper part 1 b not suspended by the suspension substrate 2 c is provided in FIG. 8 , two or more areas 1 c maybe provided.
[0053] Accordingly, as expressed in Equation 1 shown above, the length a of the shorter side 1 ba of the cavity upper part 1 b decreases, which brings about an effect of an increase in the withstanding pressure P of the cavity upper part.
[0054] In the present embodiment, the through interconnection 7 maybe arranged in the area 1 c not suspended by the suspension substrate 2 . In this case, the through interconnection 7 can be configured not to be covered with the suspension substrate 2 .
Fourth Embodiment
[0055] Hereinbelow, a MEMS-type angular velocity sensor will be described as a fourth embodiment of the present invention. In particular, an example of using a capacitive sensing angular velocity sensor as the MEMS-type angular velocity sensor will be described.
[0056] FIG. 9 is a plan view (upper view) of an angular velocity sensor chip 11 a according to the fourth embodiment of the present invention. FIG. 10 is a cross-sectional view along X-X in FIG. 9 . FIG. 11 is a cross-sectional view along XI-XI in FIG. 9 . FIG. 12 is a plan view illustrating the XII-XII cross-section in FIG. 10 . FIG. 13 is a plan view illustrating the XIII-XIII cross-section in FIG. 10 .
[0057] The present structure can be prepared by a similar method to that of the structure illustrated in FIGS. 1, 2, 3, 4, 5 , and 6 but differs in a structure of a vibrator prepared in the device substrate 4 . In describing FIGS. 9, 10, 11, 12, and 13 below, detailed description of similar components to those in FIGS. 1, 2, 3, 4, 5, and 6 will be omitted, and different points will mainly be described.
[0058] In the present embodiment, the angular velocity sensor chip 11 a has a configuration in which the cavity substrate 1 and the support substrate 5 are attached to the device substrate 4 forming a below-mentioned vibrator therein and are sealed in an airtight manner in a vacuum or in atmospheric pressure, and in which the cavity substrate upper part 1 b is suspended by the suspension substrate 2 .
[0059] Meanwhile, in the suspension substrate 2 , as described in the second embodiment, the length of the shorter side 2 aa of the suspension substrate 2 a may be a length generating in the cavity substrate upper part 1 b the area 1 c not suspended by the suspension substrate 2 a. Also, as described in the third embodiment, the plurality of suspension substrates 2 may be provided.
[0060] The angular velocity sensor chip 11 a is assembled into the chip package 19 in a similar manner to FIG. 6 .
[0061] In the angular velocity sensor chip 11 a, a left-side vibrating unit 4 q 1 and a right-side vibrating unit 4 q 2 are arranged to be symmetrical and opposed to each other and are connected via a link beam 4 p. That is, the vibrating unit 4 q 1 and the vibrating unit 4 q 2 are line-symmetrical across a center line 100 as illustrated in FIG. 12 . As for a part formed only by the device substrate 4 , both of the vibrating units are movable with respect to the support substrate 5 via the anchors 4 c and the insulating film 6 , and the vibrating units 4 q 1 and 4 q 2 are designed to have equal natural vibration frequency.
[0062] On the device substrate 4 , a weight 4 h, serving as a first vibrator, is formed, and to the weight 4 h, support beams 4 i are connected in a direction perpendicular to a driving direction of the vibrator. The other ends of these support beams 4 i are respectively connected to the anchors 4 c provided in the direction perpendicular to the driving direction. The weight 4 h serving as the first vibrator can vibrate in an X-axial direction due to the support beams 4 i. Also, some of the anchors 4 c can electrically be connected to the aforementioned through interconnection 7 similarly to the anchor 4 d and are used to electrically connect the vibrator side to an external circuit.
[0063] Comb-like driving electrodes 41 formed in the device substrate 4 are formed outside the weight 4 h serving as the first vibrator. Comb-like driving electrodes 4 m are formed on the device substrate 4 and the insulating film 6 to face the comb-like driving electrodes 4 l and are fixed to the support substrate 5 .
[0064] The driving electrode 4 m is electrically connected to the pad 9 a via the through interconnection 8 and the planar interconnection 9 on the cavity substrate and is connected to an external oscillating circuit. When a predetermined frequency signal is applied to the driving electrode 4 m, an electrostatic force is generated between the electrodes 4 l and 4 m, and the weight 4 h serving as the first vibrator vibrates in the X-axial direction.
[0065] On the device substrate 4 , a weight 4 j , serving as a second vibrator, is formed inside the weight 4 h serving as the first vibrator. On the upper and lower sides of the weight 4 j, detection beams 4 k extending in an equal direction to the vibrating direction of the weight 4 h are provided. That is, one end of the beam 4 k is connected to the weight 4 j. The other end of the beam 4 k is connected to the weight 4 h serving as the first vibrator. The weight 4 j serving as the second vibrator is movable against the support substrate 5 and can vibrate in association with the weight 4 h serving as the first vibrator due to the support beams 4 k and also vibrate in the Y-axial direction perpendicular to the X-axial direction.
[0066] As a means to detect displacement of the weight 4 j serving as the second vibrator in the Y-axial direction, comb-like detection electrodes 4 n are provided on the device substrate 4 to be adjacent to the weight 4 j . Comb-like detections 4 o are provided at positions facing the detection electrodes 4 n. The detection electrodes 4 o are formed on the device substrate 4 and the insulating film 6 and are fixed to the support substrate 5 . The detection electrode 4 o is electrically connected to the pad 9 a via the through interconnection 8 and the planar interconnection 9 on the cavity substrate 1 and is connected to an external signal processing circuit.
[0067] When the weight 4 j serving as the second vibrator is displaced in the Y-axial direction, capacitance between the electrodes 4 n and 4 o changes, and the electrode 4 o outputs a signal corresponding to the capacitance.
[0068] By arbitrarily setting the mass of the weight 4 h serving as the first vibrator and the weight 4 j serving as the second vibrator and the shapes of the support beams 4 i, the weight 4 h and the weight 4 j vibrate in the X-axial direction with natural vibration frequency of fx.
[0069] Also, by arbitrarily setting the mass of the weight 4 j serving as the second vibrator and the shapes of the detection beams 4 k, the weight 4 j vibrates in the Y-axial direction as well with natural vibration frequency of fy.
[0070] The angular velocity sensor according to the present embodiment is operated in the following manner.
[0071] First, alternating voltage with frequency of f is applied to the driving electrode 4 m in FIG. 12 so that the left-side vibrating unit 4 q 1 and the right-side vibrating unit 4 q 2 may vibrate in opposite phase to cause an electrostatic force to be generated between the electrodes 4 m and 4 l and cause the weight 4 h serving as the first vibrator to vibrate in the X-axial direction. At this time, the weight 4 j serving as the second vibrator vibrates in the X-axial direction in association with the weight 4 h. At this time, the relationship between displacement x of the weight 4 h in the X-axial direction and speed v thereof is expressed by Equation 5.
[0000] x=Xe sin (2πft)
[0000] v= 2 πfXe cos (2πft) (Equation 5)
[0000] In Equation 5, f is frequency, Xe is amplitude, and t is time.
[0072] When angular velocity Ω is applied to the angular velocity sensor in a direction of an axis (Z) perpendicular to the drawing sheet of FIG. 12 in a state in which the weight 4 h and the weight 4 j vibrate in the X-axial direction, a Coriolis force Fc (Equation 6) is generated in the Y-axial direction. The weight 4 j is displaced in the Y-axial direction by the Coriolis force Fc.
[0000] Fc=2mΩv (Equation 6)
[0000] In Equation 6, m is mass of the weight 4 j.
[0073] The weight 4 j serving as the second vibrator vibrates in the Y-axial direction by the Coriolis force Fc expressed in Equation 6, and capacitance between the detection electrodes 4 n and 4 o changes. By detecting the capacitance change, the angular velocity Ω around the Z axis can be detected.
[0074] Meanwhile, as a method for measuring the displacement amount of the weight 4 j serving as the second vibrator, voltage to be applied between the electrodes 4 n and 4 o may be servo-controlled so that the capacitance change between the detect ion electrodes 4 n and 4 o, that is, the displacement amount of the weight 4 j in the Y-axial direction, maybe zero, and the Coriolis force Fc may be derived from the applied voltage.
[0075] Also, since the left-side vibrating unit 4 q 1 and the right-side vibrating unit 4 q 2 arranged to be symmetrical and opposed to each other are provided, both of the vibrating units vibrate in opposite phase. Accordingly, while external acceleration is cancelled, a detection signal of angular velocity can be detected with high sensitivity as the sum of the two vibrating units. As another advantage, leakage of vibration of the vibrating units to an outside can be restricted.
[0076] Further, the present invention can be applied to a MEMS device having a cavity as well as the acceleration sensor and the angular velocity sensor. By suspending a cavity upper part by means of a suspension substrate, an effect of improvement in withstanding pressure of the cavity upper part can be obtained without thickening the cavity substrate.
Fifth Embodiment
[0077] Hereinbelow, a fifth embodiment of the present invention will be described with reference to FIG. 14 . FIG. 14 is a plan view of the acceleration sensor chip according to the fifth embodiment of the present invention. In the present embodiment, an example of using a capacitive sensing acceleration sensor as a MEMS-type acceleration sensor will be described. However, a capacitive sensing angular velocity sensor or another sensor may be used as the MEMS-type sensor.
[0078] In the present embodiment, a first acceleration sensor 20 A detecting acceleration in the y direction and a second acceleration sensor 20 B detecting acceleration in the x direction are provided. To include the first acceleration sensor 20 A and the second acceleration sensor 20 B in one sensor chip 11 , two cavities 1 a A and 1 a B are provided in one sensor chip 11 . The number of sensors included in the sensor chip 11 is not limited to one or two, and more sensors can be included. Also, the number of sensor kinds is not limited to one, and plural kinds of sensors may be combined. In this manner, by providing a plurality of cavities in accordance with the number of sensors included in the sensor chip 11 , the function of the sensor chip 11 can be enhanced.
[0079] Effects obtained by the aforementioned respective embodiments are summarized in the following manner.
[0080] In the semiconductor sensor device including the cavity substrate, the configuration in which the cavity upper part of the cavity substrate is provided with the wider suspension substrate than the outer circumference of the cavity upper part, and in which the cavity upper part is thus suspended, provides the following effect. As described in Equation 1 shown above, the withstanding pressure P of the cavity upper part is a function for the thickness h of the cavity upper part and the stress σ. At this time, since the cavity upper part is thicker due to the suspension substrate, the withstanding pressure P is improved. At this time, by making the suspension substrate larger than the outer circumference of the cavity, an increase of the stress σ to the end of the cavity upper part can be restricted by the suspension substrate, and the withstanding pressure P of the cavity upper part can be improved. Accordingly, by using such a configuration, a structure in which the withstanding pressure of the cavity upper part is improved can be achieved without thickening the cavity substrate itself.
[0081] Also, the configuration in which the length of the shorter side of the suspension substrate is a length that is shorter than the shorter side of the cavity upper part and that generates in a part of the cavity upper part the area not suspended by the suspension substrate provides the following effect. That is, as described in Equation 1 shown above, the length a of the cavity shorter side is short, and the withstanding pressure P can be improved. Also, since the end portion on the cavity longer side, to which the maximum stress is applied, is exposed, one can observe the area and can easily determine whether or not the cavity breaks against the withstanding pressure.
[0082] Further, the configuration in which the plurality of suspension substrates are provided provides the following effect. That is, as described in Equation 1 shown above, the length a of the cavity shorter side is short, and the withstanding pressure P can be improved.
REFERENCE SIGNS LIST
[0000]
1 cavity substrate
1 1 cavity
1 b cavity upper part
1 ba shorter side of cavity upper part
1 bb longer side of cavity upper part
1 c area of cavity upper part not suspended
2 suspension substrate
2 a suspension substrate
2 aa shorter side of suspension substrate 2 a
2 ab longer side of suspension substrate 2 a
2 b suspension substrate
3 adhesive
4 device substrate
4 a weight
4 b support beam
4 c anchor
4 d anchor (connected to through interconnection)
4 e detection electrode
4 f fixed electrode
4 g cavity
4 h weight (first vibrator)
4 i support beam
4 j weight (second vibrator)
4 k beam (for detection)
4 l driving electrode (side of weight 4 h )
4 m driving electrode (fixed to support substrate)
4 n detection electrode (side of weight 4 j )
4 o detection electrode (fixed to support substrate)
4 p link beam
4 q 1 vibrating unit
4 q 2 vibrating unit
5 support substrate
5 a cavity
6 insulating film
7 through interconnection
8 insulating film
9 planar interconnection
9 a pad
9 b through interconnection upper part
10 insulating film
10 a pad opening portion
11 acceleration sensor chip
11 a angular velocity sensor chip
12 circuit board
13 adhesive
14 wire bonding
15 lead frame
16 adhesive
17 wire bonding
18 plastic
19 chip package
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The purpose of the present invention is to improve the pressure resistance of a cavity in a semiconductor sensor device employing a resin package, and to do so without adversely affecting the embeddability of an electrically conductive member. The semiconductor sensor device has a gap 1 a sealed in an airtight manner inside a laminate structure of a plurality of laminated substrates 1, 4, and 5, and has a structure in which the outside of the laminate structure is covered by a resin, wherein a platy component 2 having at least one side that is greater in length than the length of one side of the gap 1 a along this side is arranged to the outside of an upper wall 1 b of the gap 1, the upper wall 1 b of the gap being mechanically suspended by the platy component 2.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 13/054,199 entitled “Device and Method for Cooling Solid Particles” filed Jan. 14, 2011 and being the national phase application of International patent application No. PCT/IL2009/000672 filed on Jul. 6, 2009, which claims priority from Israeli patent application No. 192,797 entitled “Device and Method for Cooling Solid Particles” filed on Jul. 14, 2008, each of which are incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] The present invention relates to a method and apparatus for providing air at semi cryogenic temperatures during preparation of various products. In particularly, this invention relates to a method and apparatus for distributing air at semi cryogenic temperatures in cooling chambers during the process of preparing fine powders.
BACKGROUND OF THE DISCLOSURE
[0003] One of the well known environmental challenges nowadays is the handling of used tires. Tire recycling, or rubber recycling, is the process of recycling vehicles' tires that are no longer suitable for use on vehicles due to wear or irreparable damage. These tires are among the largest and most problematic sources of waste, due to the large volume produced and their durability. Those same characteristics, which make waste tires such a problem, also make them one of the most re-used waste materials, as the rubber is very used waste materials, as the is very resilient and can be reused in other products. Approximately, one tire is discarded per person per year. Tires are also often recycled for use on basketball courts and new shoe products. These scrap tires are an ecological predicament in all countries in which automobiles and trucks are a standard mode of transportation. Over the years, many more tires cast off in monumental piles than recycled or burned. It is estimated that in the US alone there are in excess of 1 billion tires in illegal tire piles, generating dangerous conditions of uncontrollable fires, air pollution as well as health hazards.
[0004] To date, most discarded tires were destined to be burned, assisting in alleviating an unending energy crisis. However, since the recognition by meteorologists of pending earth warming trends, burning tires is quickly becoming unacceptable solution and in some countries even illegal. Also, to date, many of the waste tires are simply shredded and buried in landfills. This too has become an undesirable solution as more and more countries recognize the danger in underground buried tires or tire parts, due to the adverse effect on the diminishing underground supplies of fresh water. Finally, tire piles serve as breeding grounds to colonies of disease infected rodents and incubation hot beds for dangerous and deadly insects. It is therefore clear that recycling must be the only acceptable and sustainable solution to the increasing problem of scrap tires.
[0005] Recognizing all of the above, several attempts have been made to reduce the increasing number of scrap tires discarded annually by recycling them. Tire recycling has traditionally been accomplished using three distinctly different technologies:
[0006] All mechanical ambient grinding the rubber;
[0007] Cryogenically, freezing and crushing the rubber; and
[0008] Pyrolysis or microwave treatment to melt rubber.
[0009] There are quite few aspects involved in implementing the second type of technology, namely, the cryogenically, freezing and crushing the rubber to produce granular rubber, which may be used as a supplementary material in fuel or in road building, etc. One of the aspects involved in this technology is the step of exposing the crushed rubber to reduced temperatures e.g. to a point of embrittling the synthetic rubber.
[0010] Many conventional cryogenic recycling processes require the use of liquid nitrogen or solid carbon dioxide to lower the temperature of the material to be recycled to a point where a proceeding step of the process can yield a granular material such as a powder. However, such cryogenic processes are usually expensive to implement and to operate.
[0011] Many solutions were proposed in the past to improve this cooling step of the process. Few of these solutions are the following:
[0012] U.S. Pat. No. 4,273,294 discloses an improvement of conventional cryogenic grinding system incorporating an impact mill by providing means to allow at least 70% of the embrittled material entering the mill to bypass the mill's inlet and means to restrict the flow of the cold gas through the impact mill.
[0013] U.S. Pat. No. 5,408,846 describes a cooling device for lowering the temperature of rubber or polystyrene materials for recycling purposes. The cooling device has an input feeder which inputs the material to be treated into a cooling chamber. The cooling chamber is an elongated chamber. The cooling chamber receives cold air from an external air refrigeration unit and circulates that air within the chamber. The material input into the cooling chamber is circulated therein by a circulating shaft. After 15-20 minutes, the input material is discharged through an output on the opposite end of the cooling chamber. The material discharged temperature is −80° C. or lower.
[0014] U.S. Pat. No. 5,568,731 discloses an ambient air freezing system for producing chilled air in the cryogenic range of −120° C. to −180° C. without the use of cryogenic chemicals or other refrigerants.
[0015] U.S. Pat. No. 6,360,547 describes a method for cryogenically freezing materials, such as rubber, food, plastics by compressing ambient air to a first level, cooling the air back to an ambient temperature, compressing the air again, and then cooling the air followed by expanding the compressed air thereby cooling it down to cryogenic temperatures that is fed to the material to be processed.
[0016] U.S. Pat. No. 6,397,623 describes a cooling device in which the compressor and the expander are coupled to one crank shaft or interlocked crank shafts so as to use the expansion energy from the compressed air in the expander as an energy for compressing the outside air in the compressor, thereby reducing the running cost.
[0017] U.S. Pat. No. 7,125,439 discloses a method for providing clean air to an environment, by cooling incoming air, which may be contaminated with chemical, nuclear or biological contamination and removing water from the cooled air. The cooled air is passed through a regenerative pressure swing absorption system which removes the contaminants. The resulting, cleaned, air is expanded by an expander and is provided to the environment.
[0018] Our co-pending patent application published under US 2011-0204165 discloses a cooling arrangement for use in a process of preparing a fine powder, which comprises a plurality of cooling air discharging devices which allow the cooling air to be in direct contact with the grinded material (e.g. grinded tires) and a solid particles mechanical mixing means, which is adapted to ensure that no big lumps of particles are formed within said cooling arrangement.
SUMMARY OF THE DISCLOSURE
[0019] It is an object of the present invention to provide a method and apparatus for efficiently lowering the temperature of used tires, rubber and the like, to cryogenic levels.
[0020] It is another object of the present invention to provide a method and apparatus to eliminate the need for separation of the cooling fluid (e.g. air) from particles of the material being cooled that are carried together with the cooling fluid.
[0021] It is still another object of the present invention to provide a method and apparatus for rapid lowering the temperature of used tires, rubber and the like, to cryogenic levels thereby reducing the period required for the material being cooled to remain within the cooling chamber.
[0022] Other objects of the present invention will become apparent from the following description.
[0023] According to a first embodiment of the invention, there is provided a cooling arrangement adapted for use in a process of producing brittle particles, and comprising:
[0024] a first chamber having:
a solid particles feed ingress means; a solid particles mixing means; and a solid particles egress means, and a second chamber comprising at least one cooling fluid discharging means, wherein the cooling arrangement is characterized in that there is a low thermal resistance between the first chamber and the second chamber to allow cooling down the solid particles being fed to the first chamber via the solid particles feed ingress means, and wherein the solid particles feed ingress means is operative to introduce solid particles, each having a typical diameter of less than 7 mm.
[0031] According to another embodiment, the first chamber and the second chamber share a common wall. Preferably, the first chamber is substantially surrounded by the second chamber.
[0032] By yet another embodiment, the first chamber is essentially of a conical shape. Preferably, the first chamber having essentially a conical shape is completely surrounded by the second chamber. As will be appreciated by those skilled in the art, this embodiment is not restricted to any particular shape of the second chamber.
[0033] In accordance with another embodiment, the second chamber comprises a plurality of cooling air discharging means.
[0034] By still another embodiment, each of the at least one cooling fluid discharging means is adapted to receive the cooling fluid from an expanding device.
[0035] In accordance with another embodiment, the solid particles feed ingress means is located essentially at the top section of the first chamber whereas the solid particles egress means is located essentially at the bottom section of that first chamber.
[0036] By still another embodiment, the cooling arrangement is further adapted to allow the solid particles fed via the solid particles feed ingress means, to free fall onto the bottom section of the cooling arrangement, where they are mixed by a mechanical mixing means for a pre-defined period of time, and thereafter to enable their conveyance towards the next step of the powder preparation process.
[0037] In accordance with yet another embodiment, the temperature to which the solid particles are indirectly cooled (i.e. in non-direct contact) by the cooling fluid, is in the range of −70° C. to −110° C.
[0038] According to another aspect there is provided a system for use in a process of recovering material contained in used tires, wherein the system comprises: one or more compressing devices adapted to compress a cooling fluid to a pressure in the range of 10 to 15 bar;
[0039] one or more expanders operative to receive the pressurized cooling fluid and expand it so that its temperature is lowered to a level required for operating a cooling arrangement;
[0040] a cooling arrangement which comprises:
a first chamber having:
a solid particles feed ingress means; a solid particles mixing means; and a solid particles egress means, and
a second chamber comprising at least one cooling fluid discharging means,
[0046] wherein the cooling arrangement is characterized in that there is a low thermal resistance between the first chamber and the second chamber to allow cooling down the solid particles being fed to the first chamber via the solid particles feed ingress means, by the expanded cooling fluid, and
[0047] wherein the solid particles feed ingress means is operative to introduce solid particles, each having a typical diameter of less than 7 mm.
[0048] According to another embodiment, the first chamber is substantially surrounded by the second chamber.
[0049] By yet another embodiment, the first chamber has essentially a conical shape, and is completely surrounded by the second chamber.
[0050] According to still another embodiment, the system further comprises recycling means operative to enable return of the cooling fluid leaving the chamber to the one or more compressing devices.
[0051] In accordance with another embodiment, the cooling fluid is air and the second chamber comprises a plurality of cooling air discharging means.
BRIEF DESCRIPTION OF THE DRAWINGS
[0052] FIG. 1 illustrates a schematic diagram of the cooling arrangement according to the present invention for air cooling particles in a batch operation to cryogenic temperatures; and
[0053] FIG. 2 illustrates a schematic diagram of a system according to another aspect of the present invention for air cooling solid particles.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0054] A better understanding of the present invention is obtained when the following non-limiting detailed examples are considered in conjunction with the accompanying drawings.
[0055] As previously discussed, one of the objects of the present invention is to provide method and means to cool down solid particles such as recycled tires particles so that the end product of the whole recycling process, of which the cooling process described and claimed herein is a part, are particles that are in a form of fine or even ultrafine powder, typically particles of 1μ or less, and at the same time ensure the ability to re-use the cooling fluid without having to filter out the particles from the cooling fluid on one hand, while achieving a certain energy saving on the other. Although various processes were suggested in the past to produce fine powders, still, they are rather expensive to operate as they either make use of refrigerants or cryogenic chemicals, or characterized by being an inefficient ambient grinding processes. Due to high production cost and other inefficiencies, ultra fine products have not been produced in large quantities from recycled materials. The solution provided by the present invention aims to overcome these obstacles.
[0056] Although the invention is described hereinafter in connection with a process of recycling synthetic rubber such as rubber that originates from used tires, still, this is done for the convenience of the reader and the scope of the invention should not be understood to be restricted to that specific process.
[0057] Turning now to the drawings, FIG. 1 illustrates a cooling arrangement 100 that comprises chamber 105 to which a pre-defined quantity (e.g. by weight) of synthetic rubber particles derived from processing used tires is conveyed by using any applicable solids conveying means known in the art per se such as conveying belt (not shown in this Fig.), and chamber 110 to which the cooling fluid is introduced. Typically, the particles which are of an averaged diameter in the range of 1 to 5 mm are fed into the top section of chamber 105 , and allowed to free fall 120 (or alternatively to force fall, e.g. while undergoing a swirling motion) towards the bottom of chamber 105 , where they are subjected to mixing operation of mixer/stirrer 140 . During their fall, there is an initial cooling of the particles. The mixer/stirrer (e.g. a rotary device) operates to ensure that no big lumps of particles are formed and that all the particles will be subjected to the cooling air, in order to obtain a substantially homogenous temperature at the range of −80° C. to −100° C. of the synthetic rubber particles present in the chamber. At the same time, a plurality of cooling air discharging devices 130 are operative to circulate cooling air through chamber 110 in order to cool the walls of this chamber 108 and thereby to cool down chamber 105 and its content, i.e. the particles that are introduced thereto. Four such cooling air discharging devices are illustrated in FIG. 1 , demonstrating the introduction of cooling air from each side of the second chamber 110 . The air reaching each of these cooling air discharging devices is preferably cleaned, dried and compressed prior to reaching the air discharging devices, although in the alternative all these operations can be carried out within the cooling air discharging devices themselves and hence this alternative should also be considered to be encompassed by the present invention. In the present example, the cooling air is introduced to the chamber at −90° C. or lower and at a pressure of few atmospheres. When introduced into the chamber, the air expands, thereby causing its own temperature to drop further. Typically, the particles stay in chamber 104 for about 10 to 15 minutes. Thereafter, the particles are discharged at the chamber's bottom section airlock after they have become brittle and consequently easy to pulverize, to another solid conveying means for further processing the frozen granules, e.g. they can then be further ground or crushed to produce the desired ultra fine powder.
[0058] Although the present invention was described in the above example in connection with synthetic rubber particles obtained from used tires, as will be understood by those skilled in the art it can be used for cryogenically cooling materials such as polymers, rubber based materials and the like without using refrigerants or cryogenic chemicals in the process.
[0059] FIG. 2 illustrates a schematic diagram of a system 200 according to another aspect of the present invention for air cooling solid particles.
[0060] In order to obtain the cooling air required for the process any method known in the art per se, that is applicable to produce the air at the right physical conditions of temperature and pressure and the right cleanness and dryness levels can be used. For example, by ambient air is drawn and compressed by compressor 210 . It is then expanded by using multiple turbo expander machines 220 . The oil resulting from the compression is removed and the air is cleaned and dried before compression. The cooled air leaving the turbo expander machines 220 at a temperature in the range of from about −80 to about −100° C. is fed into chamber 240 of cooling arrangement 230 .
[0061] A suitable filter for the air preparation process could be an inertial separator. This may be achieved by passing the air through a filter, such as a Borosilicate micro-fiber filter, in which water, oil and particles are removed using a coalescing effect. Alternatively a silica gel or an activated alumina could be used as an adsorbent, so as to dry the air by chemically reacting to the water vapor in the air within the filter to adsorb and remove the water vapor.
[0062] Another option is using a thermodynamic cycle, otherwise known as the “Russian cycle”, where the compressor and turbo expander are located in one cylinder and chamber connected horizontally with the motor so as to use the expansion energy from the compressed air in the expander as an energy for compressing the outside air in the compressor, thereby reducing the running cost. The unit is environmentally friendly low-temperature cycle (up to −110° C.) enclosed in one functional block aggregate, and can be fully automated.
[0063] The air passing through chamber 240 cools down chamber 240 , thereby causing the cooling down of chamber 250 and the particles contained therein. After passing through chamber 240 , the cooling air is returned to compressors 210 where it will be compressed again. This way, only a small amount of ambient air will have to be drawn by compressors 210 , and for the air leaving the compressors at about 10 to 15 bars, less energy will have to be invested every time such a cycle occurs.
[0064] As will be appreciated by those skilled in the art, although the particles themselves undergo a batch type of operation as they are maintained within the chamber for a predefined period of time, still, the recycling of the cooling air is a continuous type of operation, independent of the process which the particles are subjected to.
[0065] While only the above embodiments of the present invention have been illustrated and described, it is to be understood that many changes and modifications may be made thereto without departing from the spirit and scope of the invention as defined in the appended claims.
[0066] The present invention has been described using non-limiting detailed descriptions of preferred embodiments thereof that are provided by way of example and are not intended to limit the scope of the invention. It should be understood that features described with respect to one embodiment may be used with other embodiments. Variations of embodiments described will occur to persons of the art. Furthermore, the terms “comprise”, “include”, “have” and their conjugates shall mean, when used in the claims “including but not necessarily limited to”. Also when term was used in the singular form it should be understood to encompass its plural form and vice versa, as the case may be.
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A cooling arrangement and system are provided for use in a process of producing brittle particles, and comprising: a first chamber having: a solid particles feed ingress means; a solid particles mixing means; and a solid particles egress means, and a second chamber comprising at least one cooling fluid discharging means, wherein the cooling arrangement is characterized in that there is a low thermal resistance between the first chamber and the second chamber to allow cooling down the solid particles being fed to the first chamber via the solid particles feed ingress means, and wherein the solid particles feed ingress means is operative to introduce solid particles, each having a typical diameter of less than 7 mm.
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TECHNICAL FIELD
[0001] The invention relates to a handover control mechanism for a mobile communication system. In particular, the invention relates to a method and apparatus for triggering the seamless handover of an established connection from circuit switched over packet switched domain to circuit switched domain, for example a Voice-over-IP call.
BACKGROUND
[0002] IP Multimedia (IPMM) services provide a dynamic combination of voice, video, messaging, data, etc, within the same session. By growing the numbers of basic applications and the media which it is possible to combine, the number of services offered to the end users will grow, and the inter-personal communication experience will be enriched. This will lead to a new generation of personalised, rich multimedia communication services, including so-called “combinational IP Multimedia” services.
[0003] IP Multimedia Subsystem (IMS) is the technology defined by the Third Generation Partnership Project (3GPP) to provide IP Multimedia services over mobile communication networks. IMS provides key features to enrich the end-user person-to-person communication experience through the integration and interaction of services. IMS allows new rich person-to-person (client-to-client) as well as person-to-content (client-to-server) communications over an IP-based network. The IMS makes use of the Session Initiation Protocol (SIP) to set up and control calls or sessions between user terminals (or user terminals and application servers). The Session Description Protocol (SDP), carried by SIP signaling, is used to describe and negotiate the media components of the session. Whilst SIP was created as a user-to-user protocol, IMS allows operators and service providers to control user access to services and to charge users accordingly. Other protocols are used for media transmission and control, such as Real-time Transport Protocol and Real-time Transport Control Protocol (RTP/RTCP), Message Session Relay Protocol (MSRP), and Hyper Text Transfer Protocol (HTTP). IMS requires an IP based access network which for example could be a 3GPP Packet Switched (PS) network, or some other access network such a fixed broadband or WiFi network.
[0004] A fundamental requirement for real-time service provision is the seamless handover of services for subscribers roaming across cell boundaries of the radio access network (RAN). Traditional circuit switched (CS) based call services have been designed to meet this requirement. In the case of 2G and currently implemented 3G networks, PS real time handover with low latency is not provided for although service continuity is achieved at the terminal side by ordering a session to be moved from one cell to another, i.e. there is no prepare phase to shorten latency when moving cell.
[0005] Real time PS handover is standardized in 3GPP for 3G networks, but the feature has not yet been deployed. It is expected that when High-Speed Downlink Packet Access (HSDPA) is deployed, or shortly thereafter, the mechanisms needed for fast PS handover will be also be deployed. In the initial implementation stage, roll-out of this feature across 3G networks will inevitably be patchy. For 2G networks, fast and efficient PS handover procedures in the packet switched (PS) domain within the 2G network (and between 2G and 3G networks) have only recently been standardized in 3GPP TS 43.129 for GSM/EDGE networks but are not yet deployed. Support for PS handover in 2G networks is never likely to be comprehensive (if implemented at all), yet handover of PS calls would be desirable as 2G networks will continue to provide a fallback network for 3G subscribers in the case of limited 3G network coverage. It can also be expected that the next generation radio and core network which are currently being specified under the name LTE (Long Term Evolution) and SAE (System Architecture Evolution) in 3GPP will also have limited coverage, and that these networks will also require fallback to 3G and 2G networks.
[0006] It is expected that in the future a major user of PS services will be Voice-over-IP (VoIP) applications. VoIP calls will be particularly sensitive to even relatively minor service interruptions caused by inter-cell handovers. As long as a terminal engaged in a VoIP call can perform PS handover to another cell (the “target cell”), the interruption can be kept short enough to avoid any noticeable drop in perceived quality. However, if either the current cell or the target cell do not support PS handover, a noticeable interruption is likely to occur as packets will be lost during the transition period. Consequently, until all RAN cells support PS handover, the provision of IMS services such as voice and video calls utilising the PS domain are likely to result in users receiving a reduced quality of service when crossing cell boundaries.
[0007] Mobile circuit switched (CS) services based on GSM and WCDMA radio access are a world-wide success story and allow obtaining telecommunication services with a single subscription in almost all countries of the world. Also today, the number of CS subscribers is still growing rapidly, boosted by the role out of mobile CS services in dense population countries such as India and China. This success is furthermore extended by the evolution of the classical Mobile Switching Centre (MSC) architecture into a softswitch solution which allows using packet transport infrastructure for mobile CS services.
[0008] Recently the 3GPP work item “Evolved UTRA and UTRAN” (started in summer 2006) defined a Long-Term Evolution (LTE) concept that assures competitiveness of 3GPP-based access technology. It was preceded by an extensive evaluation phase of possible features and techniques in the RAN workgroups that concluded that the agreed system concepts can meet most of the requirements and no significant issue was identified in terms of feasibility.
[0009] LTE will use orthogonal frequency division multiplexing (OFDM) radio technology in the downlink and single-carrier frequency division multiple access (SC-FDMA) for the uplink, allowing at least 100 Mbps peak data rate for downlink data rate and 50 Mbps for uplink data rate. LTE radio can operate in different frequency bands and is therefore very flexible for deployment in different regions of the world.
[0010] FIG. 1 illustrates schematically the System Architecture Evolution (SAE) and LTE interfaces. In parallel to the RAN standardization 3GPP also drives a System Architecture Evolution (SAE) work item to develop an evolved core network (CN). The SAE core network is made up of core nodes, which are further divided into Control Plane (Mobility Management Entity (MME) 21 ) and User Plane Gateway 22 (Serving Gateway and PDN Gateway) nodes. In the context of the present invention, the terms Access Gateway (AGW) and SAE GW are used to depict both the Serving Gateway and the PDN Gateway nodes and functions. In the terminology currently used AGW-UP contains both User Plane Entity (UPE) and Inter-Access Anchor (IASA) functionality. The MME 21 is connected to the E-UTRAN NodeB (eNodeB 23 , 23 ′) via the S 1 -MME interface and the Serving Gateway 22 is connected to the eNodeB 23 , 23 ′ via the S 1 -U interface.
[0011] Common to both LTE and SAE is that only a Packet Switched (PS) domain will be specified, i.e. all services are to be supported via this domain. GSM (GPRS) and WCDMA however provide both PS and Circuit Switched (CS) access simultaneously.
[0012] Hence, if telephony services shall be deployed over LTE radio access and SAE core networks, an IMS based service engine (or similar) is needed. It has been recently investigated how to use LTE/SAE as access technology to the existing Mobile Switching Subsystem (MSS) infrastructure. The investigated solutions are called “CS over LTE/SAE”, or briefly just “CS over LTE” (CSoLTE), solutions.
[0013] The basic CSoLTE architecture for these solutions is shown in FIG. 2 . The Packet Mobile Switching Center (PMSC) 24 can be serving both traditional 2G and 3G RANs 41 and the new CS over LTE based solutions 42 . In addition to MSC-S 29 and MGW 30 , Packet MSC 24 contains two new logical functions called Packet CS Controller (PCSC) 27 and Interworking Unit (IWU) 28 that are further described in relation to FIG. 3 . A public switched telephone network 43 and a public data network 44 provide connectivity.
[0014] In relation to both FIGS. 2 and 3 , the communication between the terminal and the PMSC 24 is based on the standard Gi interface which is also called as a SGi interface in the SAE terminology. This means that all direct communication between the terminal and the PCSC 27 and the IWU 28 in the PMSC 24 is based on Internet Protocol (IP) and that the terminal is visible and reachable using an IP-address via the Access Gateway (AGW) 22 . This communication between the terminal 31 and the PMSC 24 is divided into two different interfaces, U 8 c for the control plane and U 8 u for the user plane. The U 8 c is terminated in the PCSC 27 and the PCSC 27 has also an Rx interface to the Policy and Charging Rule Function (PCRF) 33 for authorising of LTE/SAE bearers. The U 8 u is terminated in the IWU 28 .
[0015] One solution for providing CS services over the LTE radio access is called “CS Fallback” and means that the terminal is performing SAE Mobility Management (MM) procedures towards the MME 21 while camping on LTE access 42 . The MME registers the terminal in the MSC-Server (MSC-S 29 ) for CS based services. When a mobile terminating call or other transaction request resulting in a page for CS services is received in the MSC-S it is forwarded to the terminal via the MME and then the terminal performs fallback to the 2G or 3G RANs. Similar behavior applies for Mobile originated CS services and when these are triggered and the terminal is camping on LTE access, it will fallback to 2G or 3G RANs and trigger the initiation of the CS service there.
[0016] The CSoLTE control plane protocol architecture between the terminal 31 and the PMSC 24 (i.e. the U 8 c interface) is shown in FIG. 4 . Interposed between the two is the eNodeB 23 and the AGW 22 . This architecture is based on IP protocols (IP, TCP, UDP) and an additional tunnelling protocol named as U 8 -Circuit Switched Resources (U 8 -CSR). This protocol carries the Mobility Management (MM) and all the protocol layers above MM transparently between the terminal 31 and the PMSC 24 .
[0017] The CSoLTE user plane protocols between the terminal 31 and the PMSC 24 (i.e. the U 8 u interface) are shown in FIG. 5 . EnodeB 23 and AGW 22 are arranged between the two. This architecture is based on IP protocols (IP, UDP, RTP) that are used to transmit the necessary voice and data communicating (e.g. AMR coded voice) between the terminal 31 and the PMSC 24 .
[0018] No known solutions exist for Handover from the CSoLTE based solutions to traditional CS domain.
[0019] It is an object of the present invention to obviate at least some of the above disadvantages and to provide a method and apparatus for triggering the seamless handover of an established connection from a circuit switched service over packet switched domain to a circuit switched domain.
SUMMARY
[0020] According to a first aspect of the present invention, there is provided a method for initiating handover of a circuit switched service using a packet switched bearer of a mobile station from a packet switched (CSoLTE) domain to a circuit switched (CS) domain in a mobile communications network comprising a radio network and a core network. It is communicated to the mobile station that a circuit switched handover procedure is to be initiated, said communication comprising sending a circuit switched handover required message to the mobile station, said circuit switched handover required message comprising identification of a circuit switched handover target cell. The mobile station sends a circuit switched handover required message to the circuit switched core network handling said communication, said handover-required message comprising identification of the handover target cell.
[0021] According to a second aspect of the present invention, there is provided a method for initiating handover of a circuit switched service using a packet switched bearer of a mobile station from a packet switched domain to a circuit switched domain in a mobile communication network comprising a radio network and a core network. The mobile station receives a communication that a circuit switched handover procedure is to be initiated, said communication comprising a circuit switched handover required message, said circuit switched handover required message comprising identification of a circuit switched handover target cell. The mobile station sends a circuit switched handover required message to the core network, said handover-required message comprising identification of the handover target cell.
[0022] According to a third aspect of the present invention, there is provided a mobile station adapted for assisting in initiating handover of a circuit switched service using a packet switched bearer of the mobile station from a packet switched domain to a circuit switched domain in a mobile communication network comprising a radio network and a core network. The mobile station comprises means for receiving a communication that a circuit switched handover procedure is to be initiated, said communication comprising a circuit switched handover required message, said circuit switched handover required message comprising identification of a circuit switched handover target cell, and means for sending a circuit switched handover required message to the circuit switched core network, said handover-required message comprising identification of the handover target cell.
[0023] According to a fourth aspect of the present invention, there is provided a method for initiating handover of a circuit switched service using a packet switched bearer of a mobile station) from a packet switched domain to a circuit switched domain in a mobile communications network comprising a radio network, a handover-deciding node and a core network. The handover-deciding node determines whether the mobile station is using packet switched communication services. The handover deciding node sends a communication to the mobile station indicating that a circuit switched handover procedure is to be initiated, said communication comprising a circuit switched handover required message, said circuit switched handover required message comprising identification of a circuit switched handover target cell.
[0024] According to a fifth aspect of the present invention, there is provided a handover-deciding node adapted to assist in initiating handover of a circuit switched service using a packet switched bearer of a mobile station from a packet switched domain to a circuit switched domain in a mobile communications network comprising a radio network, and a core network. The handover-deciding node comprises means for determining whether the mobile station is using packet switched communication services, and means for sending a communication to the mobile station indicating that a circuit switched handover procedure is to be initiated, said communication comprising a circuit switched handover required message, said circuit switched handover required message comprising identification of a circuit switched handover target cell.
[0025] An advantage of the present invention is that the CSoLTE calls in LTE/SAE access may be moved to 2G/3G RAN CS domain when the LTE coverage is lost.
[0026] Moreover no changes are needed to the existing CS CN infrastructure (i.e. the other MSCs than the PMSC may remain unmodified).
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 illustrates schematically SAE and LTE interfaces.
[0028] FIG. 2 illustrates schematically a CSoLTE architecture.
[0029] FIG. 3 illustrates schematically a CSoLTE reference architecture.
[0030] FIG. 4 illustrates schematically a CSoLTE control plane protocol architecture.
[0031] FIG. 5 illustrates schematically a CSoLTE user plane protocol architecture.
[0032] FIG. 6 illustrates schematically a handover from CSoLTE to CS: before execution—scenario 1.
[0033] FIG. 7 illustrates schematically a Handover from CSoLTE to CS: after execution—scenario 1.
[0034] FIG. 8 illustrates schematically a Handover from CSoLTE to CS: before execution—scenario 2.
[0035] FIG. 9 illustrates schematically a Handover from CSoLTE to CS: after execution—scenario 2.
[0036] FIG. 9B illustrates schematically how the network informs the eNodeB about “CSoLTE call”.
[0037] FIG. 10 illustrates schematically a MO call using CSoLTE: Terminal informs the eNodeB about “CSoLTE call”.
[0038] FIG. 11 . illustrates schematically a MT call using CSoLTE: Terminal informs the eNodeB about “CSoLTE call”.
[0039] FIG. 12 . illustrates schematically a Sequence Diagram for Handover from CSoLTE to UTRAN CS—scenario 1.
[0040] FIG. 13 . illustrates schematically a Sequence Diagram for Handover from CSoLTE to UTRAN CS—scenario 2.
[0041] FIG. 14 . illustrates schematically a Sequence Diagram for Handover from CSoLTE to GERAN CS.
DETAILED DESCRIPTION
[0042] The present invention relates to handover from the CSoLTE based solutions to traditional CS domain (i.e. a 2G and/or a 3G RAN). It applies for the case when a terminal in CS dedicated state (over the CSoLTE solutions) is moving away from LTE coverage (i.e. is about to loose LTE coverage) to the 2G/3G RAN coverage area and when it is preferred to keep the CS connection or service and the call is handed over to the 2G/3G RAN coverage. The CS dedicated state or CS connection could mean that the terminal is engaged in CS call or some other CS related signaling transaction.
[0043] This also means that this invention applies for the CSoLTE-I and CSoLTE-D solutions as these solutions contain the usage of CSoLTE principles to transfer user plane and CS signaling connections.
[0044] The basic concept of the invention is that Handover from CSoLTE solutions is triggered to the traditional CS domain (i.e. the 2G/3G RAN). The triggering of this handover case means that the relevant LTE node (eNodeB 23 ) needs to know when the terminal 31 is engaged in a CS (or CSoLTE) call and preferably also which LTE/SAE bearers are being used for the CS call.
[0045] Once the eNodeB 23 triggers this handover case, it consists of two parallel handover requests, one request similar to the existing CS Handover request in the CN and the second one similar to the existing PS handover request. The main difference is that the CS Handover request is sent from the eNodeB 23 to the terminal 31 , which then forwards it to the PMSC 24 . Finally, the eNodeB 23 coordinates that both the CS and PS handover preparations phases are performed and commands the MS 31 to perform handover to the traditional CS domain. In addition, other PS services may also be handed over to the PS domain of the target radio access network (RAN) i.e. GSM or WCDMA radio access networks.
[0046] The situation that the present invention addresses is the following:
[0047] The terminal is initially:
[0048] 1. in CS dedicated state via CSoLTE with reserved CSoLTE resources in LTE and between the PMSC 24 and e.g. the legacy part of the CS CN,
[0049] 2. SAE/MME attached via LTE, and
[0000] has the needed LTE/SAE bearers that are used as CSoLTE resources. As part of these bearers the terminal holds an IP-address in the GGSN/AGW.
[0050] FIG. 6 illustrates schematically the Handover CSoLTE to CS before execution in the case of scenario 1.
[0051] Note 1: the CS domain may consist of MSC-S and MGW or may alternatively consist of classical MSC/VLR nodes. This is of no relevance for this invention.
[0052] Note 2: The term “scenario” is used in this document to describe different deployment alternatives and scenarios. Two different scenarios are described. In the first scenario (named scenario 1) the PMSC does not have the capability to act as a traditional MSC (i.e. serving and controlling also 2G/3G RANs).
Scenario 1
[0053] The first scenario assumes that the serving PMSC does not have the capability to act as a traditional MSC. This may be the case in the early introduction of LTE/SAE, but it can be assumed that at a later deployment phase all PMSCs will have also MSC capability.
[0054] The following actions need to take place when or before handover from CSoLTE solution to traditional CS domain (i.e. 2G/3G RAN) can take place:
[0055] 1. The eNodeB in LTE need to be aware of that the terminal is engaged in CSoLTE call and preferably which LTE/SAE bearers are used for this call. How this can be solved is described below.
[0056] 2. The path in the CN between MSC controlling the target 2G/3G RAN 41 and PMSC 24 needs to be established. The current PMSC 24 will act as an anchor point at this handover. For this action the target GERAN/UTRAN cells are identified as normally for CS handovers in legacy systems.
[0057] 3. The CS bearer in the 2G/3G RAN 41 need to be prepared for this terminal. The eNodeB 23 commands the terminal 31 to move to the CS (and PS) resources in the target 2G/3G RAN 41 .
[0058] FIG. 7 shows the handover from CSoLTE to CS after Execution under scenario 1.
Scenario 2
[0059] In the second scenario, the PMSC is also capable of functioning as a traditional MSC.
[0060] In this case, instead of handling the handover from LTE/SAE as inter-MSC handover case, this can be handled as intra-MSC, inter-system handover. This is also possible today between GSM and WCDMA RANs.
[0061] The handover procedures are very similar as in scenario 1, the only difference is that no non-anchor MSC is needed and therefore also no user plane connection between MSCs is needed. The scenario 2 is further shown in FIGS. 8 and 9 .
[0062] FIG. 8 illustrates the handover from CSoLTE to CS before execution—scenario 2
[0063] FIG. 9 illustrates the handover from CSoLTE to CS after execution—scenario 2
The ENodeB Awareness of Terminal Being Engaged In CSoLTE Call
[0064] One of the main problems to be solved for the Handover from CSoLTE to traditional CS domain is to make sure that the eNodeB 23 in LTE 42 is aware that a terminal 31 is engaged in CSoLTE call and preferably also which LTE/SAE bearers are used for the CSoLTE call. If the eNodeB is not aware of this, then it would be difficult to know when it is time to trigger normal PS handover or Handover from CSoLTE to traditional CS domain.
[0065] There are two possibilities to solve this. The first option is that the terminal 31 informs the eNodeB 23 directly when CSoLTE calls are being established or released. In this case the terminal 31 can also inform which LTE/SAE bearers are being used for the CSoLTE call.
[0066] The second option is that the SAE bearer establishment contains a flag/indication for the use of “CSoLTE” application. This would mean that when the PMSC 24 authorizes media (e.g. a PDP context) over the Rx-interface, then an indication about the application using the requested resources is also included and forwarded in the following requests between the SAE and LTE nodes and finally eNodeB 23 becomes aware of that the CSoLTE application is using the requested resources. This in principle means that the PDP context is marked as being used for “CSoLTE” application. This is further depicted in the following FIG. 9B and shown in combination with a Mobile Originated call. The same principle applies also for the Mobile Terminated calls. The new steps are shown in FIG. 9B using number 7 b, 7 c and 7 d. In addition the step 7 may be modified to include the “For CSoLTE” indication already from the PMSC. When the eNodeB receives the message in step 7 d indicating that a dedicated bearer is requested for the CSoLTE application, it can use this information for the duration of the call to decide whether the handover described in this document should be triggered.
[0067] Once the eNodeB knows that a CSoLTE call is active and which LTE/SAE bearers are used, it will be able to trigger the Handover from CSoLTE to traditional 2G/3G RAN as needed. The knowledge about which LTE/SAE bearer is being used for the CSoLTE call can be used to not trigger PS handover for these resources. This can be performed if there are LTE/SAE bearer(s) that are used solely for CSoLTE as the CSoLTE parts will be transferred to the CS domain of the target cell and there is no need for these PS resources in the target 2G/3G RAN.
[0068] FIG. 10 shows one example of the first option for Mobile Originated (MO) call using the CSoLTE solution. The main interesting part is step 6 b where the terminal 31 informs the eNodeB 23 about “CSoLTE”. If the terminal 31 should also inform the eNodeB 23 about the LTE/SAE bearers that are used for CSoLTE, then this step would need to take place later, after the steps 7 and 8 which result in an LTE/SAE bearer being created/activated for the terminal.
[0069] FIG. 11 shows another example of the first option for Mobile Terminated (MT) call using the CSoLTE solution. The main interesting part is the same as in FIG. 10 i.e. step 6 b where the terminal 31 informs the eNodeB 23 about “CSoLTE”. If the terminal should also inform the eNodeB about the LTE/SAE bearers that are used for CSoLTE, then this step would need to take place later, after the steps 7 and 8 which result in LTE/SAE bearer being created/activated for the terminal.
[0070] FIG. 11 . MT call using CSoLTE: Terminal informs the eNodeB about “CSoLTE call”
The Procedure For Handover From CSoLTE To UTRAN CS
[0071] FIG. 12 shows the relevant steps that are needed when a terminal 31 occupied in a
[0072] CSoLTE call is moving from LTE to 3G RAN for the scenario 1 case when the serving MSC for the target 3G cell is not the PMSC. The steps shown in the sequence diagram for handover from CSoLTE to UTRAN CS in the case of scenario 1 illustrated in FIG. 12 are described in the following.
[0073] Initial State: The mobile station 31 is engaged in a CS call in the CSoLTE solution. The mobile station 31 has dedicated LTE/SAE bearers allocated and these bearers could be only for the CSoLTE or also for other applications. The eNodeB 23 also knows that the mobile station 31 is engaged in CSoLTE call (as described above) The mobile station 31 is configured to perform measurements of neighbouring cells and at least one of the cells to be measured is an 3G/UTRAN cell. The mobile station 31 moves to the coverage area of the UTRAN cell and detects that cell. Simultaneously, the LTE coverage is deteriorating.
[0074] Step 1 : The mobile station 31 reports the measurements it has performed for the detected UTRAN cell. The exact details of this are not standardized yet, but it can be assumed that the UTRAN cells are measured and reported as Inter-RAT (IRAT) cells in LTE.
[0075] Step 2 : The eNodeB 23 decides to perform Handover from CSoLTE to the 3G RAN to the reported UTRAN cell. This decision is based on the knowledge of the terminal being engaged in CSoLTE call and that the reported target cell is an UTRAN cell. The following description is divided to two different parts, the CS handover and PS handover parts that are both triggered for the Handover from CSoLTE to CS procedure. The CS handover is shown as steps 3 a - 11 a and the PS handover is partly shown as steps 3 b - 11 b.
[0076] Steps 3 b - 11 b: The eNodeB 23 triggers the PS handover procedure. As this procedure is performed as normally (however not standardized yet), the steps between steps 3 b and 11 b are not described. At step 11 b, the eNodeB waits for the completion of both CS and PS handover procedures until it continues to step 12 . There is however one possible difference towards the normal PS handover procedure. The eNodeB may select to not indicate that a LTE/SAE bearer used solely for CSoLTE needs to be moved as part of the PS handover procedure.
[0077] Step 3 a: The eNodeB 23 communicates to the terminal 31 that a CS Handover procedure from CSoLTE to 3G RAN is to be triggered by sending the CS HO REQUIRED message to the terminal. The target UTRAN cell is identified also in the message using one of the existing ways to do this (i.e. i) PLMN-ID, LAC, RNC-ID and Cell Identifier, or ii) RNC-ID and Cell Identifier or iii) LAC, RNC-ID and Cell Identifier, or (iv) PLMN-ID, LAC and Cell Identifier (a so called Cell Global Identity, CGI)).
[0078] The final destination for this message is the serving PMSC 24 , but as the eNodeB doesn't know which node is PMSC or it doesn't have any ways to communicate with it (i.e. even if it would know it), the eNodeB sends the message to the terminal 31 which forwards it to the PMSC in step 4 a ).
[0079] Step 4 a: The terminal 31 forwards the request for CS handover to the PMSC 24 by sending the U 8 c -HANDOVER REQUIRED message to the PMSC. The target UTRAN cell information is included in the message.
[0080] Step 5 a: The PMSC 24 uses the target cell identifier received in the U 8 c -HANDOVER
[0081] REQUIRED message to identify the target MSC 34 for this handover request. In this case, the analysis points to the MSC and the relevant MAP signaling (MAP-Prep-Handover-Request) is triggered towards the MSC.
[0082] Step 6 a - 7 a: The target MSC 34 requests the target RNC 32 to allocate necessary CS resources for a relocation to the target cell. The target RNC informs the target MSC about the successful result of the CS resource allocation for the requested relocation.
[0083] Step 8 a: The target MSC 34 uses MAP signaling to communicate towards the source PMSC 24 (MAP-Prep-Handover-Response) that the CS relocation preparation has been performed.
[0084] Step 9 a: In this step the needed connectivity is established between the PMSC 24 and the target MSC using standard CS call control signaling.
[0085] Step 10 a: The PMSC 24 informs the terminal that CS handover has been prepared successfully by sending the U 8 c -HANDOVER COMMAND message to the terminal.
[0086] Step 11 a: The terminal 31 forwards the received indication to the eNodeB 23 by sending the CS HANDOVER COMMAND to the eNodeB. As this specific handover is about handover from LTE and CSoLTE, the eNodeB needs to wait for both the steps 11 a and 11 b to happen before it can command the mobile station 31 to move to the target UTRAN cell.
[0087] Step 12 : The eNodeB builds a “CSoLTE HANDOVER COMMAND” message and sends this message to the terminal. This message is a combination of the information retrieved as part of the performed PS and CS handover preparations.
[0088] Step 13 : The mobile station 31 accesses the target UTRAN cell using the mechanisms specified for normal hard handover.
[0089] Step 14 : The target RNC 32 informs the CN that the relocation execution trigger has been received.
[0090] Step 15 : The terminal 31 sends the Handover to UTRAN Complete message to the target RNC 32 to indicate that the handover to UTRAN has been completed.
[0091] Step 16 : By sending the Relocation complete message the target RNC 32 informs the CN that the relocation is completed. All performed steps are not shown in FIG. 12 , as these are the normal procedures performed after handover.
[0092] Step 17 : The voice payload is transported to the terminal in the target UTRAN cell.
[0093] FIG. 13 shows the relevant steps that are needed when a terminal occupied in a CS call is moving from CSoLTE to 3G RAN for the scenario 2 case when the serving PMSC 24 ′ is also functioning as the target MSC. The description of FIG. 12 applies here also expect that the steps 5 a and 8 a - 9 a are omitted.
The Procedure For Handover From CSoLTE To GSM CS
[0094] FIG. 14 shows the relevant steps that are needed when a terminal occupied in a CSoLTE call is moving from CSoLTE to GERAN CS. In the initial State the mobile station 31 is engaged in a CS call in the CSoLTE solution. The mobile station 31 has dedicated LTE/SAE bearers allocated and these bearers could be only for the CSoLTE or also for other applications. The eNodeB also knows that the mobile station 31 is engaged in CSoLTE call (as described above). The mobile station 31 is configured to perform measurements of neighbouring cells and at least one of the cells to be measured is a GERAN cell. The mobile station 31 moves to the coverage area of the GERAN cell and detects that cell. Simultaneously, the LTE coverage is getting worse.
[0095] Step 1 : The mobile station 31 reports the measurements it has performed for the detected GERAN cell. The exact details of this are not standardized yet, but it can be assumed that the GERAN cells are measured and reported as IRAT-cells in LTE.
[0096] Step 2 : The eNodeB decides to perform Handover from CSoLTE to the 2G RAN to the reported GERAN cell. This decision is based on the knowledge of the terminal being engaged in CSoLTE call and that the reported target cell is a GERAN cell. The following description is divided to two different parts, the CS handover and PS handover parts that are both triggered for the Handover from CSoLTE to CS procedure.
[0097] The CS handover is shown as steps 3 a - 11 a and the PS handover is partly shown as steps 3 b - 11 b.
[0098] Steps 3 b - 11 b: The eNodeB 23 triggers the PS handover procedure. As this procedure is performed as normally (however not standardized yet), the steps between steps 3 b and 11 b are not described. At step 11 b, the eNodeB waits for the completion of both CS and PS handover procedures until it continues to step 12 . There is however one possible difference towards the normal PS handover procedure. The eNodeB may select to not indicate that a LTE/SAE bearer used solely for CSoLTE needs to be moved as part of the PS handover procedure.
[0099] Step 3 a: The eNodeB 23 communicates to the terminal that CS Handover procedure from CSoLTE to 2G RAN is to be triggered by sending the CS HO REQUIRED message to the terminal. The target GERAN cell is identified also in the message using the normal CGI format.
[0100] The final destination for this message is the serving PMSC 24 , but as the eNodeB doesn't know which node is PMSC or it doesn't have any ways to communicate with it (i.e. even if it would know it), the eNodeB sends the message to the terminal 31 which forwards it to the PMSC 24 in step 4 a ) This message is sent from the eNode.
[0101] Step 4 a: The terminal 31 forwards the request for CS handover to the PMSC 24 by sending the U 8 c -HANDOVER REQUIRED message to the PMSC. The target GERAN cell information is included in the message.
[0102] Step 5 a: The PMSC 24 uses the target cell identifier received in the U 8 c -HANDOVER REQUIRED message to identify the target MSC 34 for this handover request. In this case, the analysis points to the MSC and the relevant MAP signaling (MAP-Prep-Handover-Request) is triggered towards the MSC.
[0103] Step 6 a - 7 a: The target MSC requests the target BSC 32 ′ to allocate necessary CS resources for CS handover in the target cell. The target BSC informs the target MSC about the successful result of the CS resource allocation for the requested handover.
[0104] Step 8 a: The target MSC 34 uses MAP signaling to communicate towards the source PMSC (MAP-Prep-Handover-Response) that the CS handover preparation phase has been performed.
[0105] Step 9 a: In this step the needed connectivity is established between the PMSC 24 and the target MSC using standard CS call control signaling.
[0106] Step 10 a: The PMSC 24 informs the terminal that CS handover has been prepared successfully by sending the U 8 c -HANDOVER COMMAND message to the terminal.
[0107] Step 11 a: The terminal 31 forwards the received indication to the eNodeB 23 by sending the CS HANDOVER COMMAND to the eNodeB. As this specific handover is about handover from LTE and CSoLTE, the eNodeB needs to wait for both the steps 11 a and 11 b to happen before it can command the mobile station 31 to move to the target GERAN cell.
[0108] Step 12 : The eNodeB 23 builds a “CSoLTE HANDOVER COMMAND message and sends this message to the terminal. This message is a combination of the information retrieved as part of the performed PS and CS handover preparations.
[0109] Steps 13 - 17 : The mobile station 31 accesses the target GERAN cell using the mechanisms specified for normal CS and PS handovers. All performed steps are not shown in FIG. 14 , as these are the normal procedures performed after CS handover.
[0110] Step 18 : The voice payload is transported to the terminal in the target UTRAN cell.
[0111] The present invention may also be used for other VoIP solutions in LTE and the marking in EnodeB could refer to “Realtime CS voice application” instead of “CSoLTE call/application”.
[0112] No doubt many other effective alternatives will occur to the skilled person. It will be understood that the invention is not limited to the described embodiments and encompasses modifications apparent to those skilled in the art lying within the spirit and scope of the claims appended hereto.
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A method for initiating handover of a circuit switched service using a packet switched bearer of a mobile station ( 31 ) from a packet switched domain to a circuit switched MS eNodeB PMSC PCRF domain in a mobile communications network comprising a radio network and a core network, said method comprising communicating to the mobile station that a circuit switched handover procedure is to be initiated, said communication comprising sending a circuit switched handover required message to the mobile station, said circuit switched handover required message comprising identification of a circuit switched handover target cell; said mobile station sending a circuit switched handover required message to the core network, said handover-required message comprising identification of the handover target cell.
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CROSS-REFERENCE TO RELATED APPLICATION
The invention described and claimed hereinbelow is also described in German Patent Application DE 10 2010 014 704.4 filed on Apr. 12, 2010. This German Patent Application, whose subject matter is incorporated here by reference, provides the basis for a claim of priority of invention under 35 U.S.C. 119(a)-(d).
BACKGROUND OF THE INVENTION
The present invention relates to a device and a method for manufacturing preforms of fiber reinforced plastic.
Today, glass fiber reinforced plastics (GFRP) and carbon reinforced plastics (CRP) are chosen increasingly often for use as the material for highly diverse applications. This is due to a growing demand for lightweight construction solutions. In the field of machine engineering and, in particular, aerotechnics and space engineering, and in the construction of wind power plants, highly stable and extremely lightweight solutions based on GFRP and CRP have become indispensible.
The advantageous properties of these materials have also proven valuable in automotive and aircraft construction, of course. Predictions call for an increasing use of GFRP and CRP components for production of very large quantities in automotive construction in particular.
In aircraft construction, which deals primarily with moving large masses, the performance of a product can be increased greatly by the use of lightweight construction solutions. For example, reducing weight can also help to minimize perpetual costs such as fuel costs.
The advantage of fiber reinforced plastics is their high specific strength and stiffness combined with very low density. This is a clear advantage over metallic materials. Due to the very low density of the fibers used, and given that density of the plastics used is even lower, these lightweight construction materials are clearly superior to classically used metallic materials in terms of weight.
The entire production of components made of fiber reinforced plastics is still highly manually oriented. This results in very high production costs, thereby rendering production of large quantities, let alone mass production, unaffordable at this time. Semi-automated or fully automated processes have become known only for components having very simple geometries. For example, pultrusion is used to manufacture straight shapes having a constant cross section. This is suitable for manufacturing plastic railings, plastic ladders, tent stakes, or bed frames, for example.
The curved structural components required in the aircraft and automobile industries in particular can only be produced manually at this time, which is an elaborate and tedious process. It is precisely such curved parts composed of fiber reinforced plastics, which are often required for aerodynamic reasons or due to greater stiffness, that are becoming increasingly significant in the field of automobile or aircraft construction.
To manufacture components having greater geometric complexity, so-called “integral components”, the desired structures composed of fiber semi-finished products such as rovings, wovens, non-wovens, fleeces, interwovens, or the like, are first draped into the desired shape. This takes place, for instance, by using a certain precut blank of the materials which are then draped around or in devices that are convex, concave, or have other three-dimensional shapes. Finally, the formed bodies, which are usually composed of a plurality of semi-finished products, are sewn together and impregnated with a plastic which sets to form the so-called matrix.
The disadvantages of this manufacturing method are, in particular, the small holes produced during sewing, which can negatively affect stability, for instance, since the seams can also destroy fibers.
Document EP 1 504 880 A makes known an automated process and a machine intended for use therefor, by way of which components having simpler geometric shapes, such as L, S, H, or hat shapes, can be manufactured out of prepregs in a semi-automated process. Slight curvatures can be created by tightening up the prepregs that are used in a special pressing mold during the process of manufacturing the component such that the component has a respective radius.
The disadvantage of such a method is that only very slight curvatures can be produced, and only prepregs but no other types of starting materials can be used. Prepregs are expensive and they must be covered with special sheets when stored, to prevent them from sticking together. These sheets must be removed, of course, before various layers are combined. This also complicates a continuous production of components. In addition, prepregs have a limited storage life before processing, and they must be stored in cool conditions.
Furthermore, the prepreg stack that was formed must be covered with other special sheets at the top and the bottom, to prevent them from sticking in the heated press.
To attain a desired curvature, these sheets must be prefabricated with precisely this curvature, which also requires a considerable amount of effort.
If structural components having greater complexity are required, for instance, they must be manufactured at this time as individual components having a simple geometry, which can then be combined to form the desired assembly using complex assembly processes. This production method results in very high costs, greater weight, and very long production times.
SUMMARY OF THE INVENTION
The problem addressed by the present invention is therefore that of providing a method and a device which enable preforms and components made of fiber reinforced plastics to be manufactured more cost effectively.
This problem is solved by a method for the manufacture of preforms of fiber reinforced plastic and by a device for carrying out such a method in accordance with the present invention.
Using the method according to the invention for manufacturing preforms of fiber reinforced plastic, continuously supplied fiber layers are first reshaped into a predetermined cross section by way of transverse reshaping. A profile produced in this manner is then curved in a specific manner by longitudinal reshaping in a further step.
The method according to the invention offers many advantages. One considerable advantage is that a structural component having high geometric complexity can be manufactured continuously and in an automated manner. The transverse reshaping into a target cross section is attained by way of reshaping using CNC-machined mold cores. In that particular case, the fiber layers are shaped around the mold cores using pressure rollers, and thereby gradually assume the desired section shape. A further advantage is that curved components can also be manufactured using the method according to the invention. It is also particularly advantageous that dry fiber material, which does not stick together and is easily stored, can also be used for this method.
This applies primarily to the manufacture of complex structural components. The preforms are therefore preferably composed of at least two sections.
To provide a truly continuous method which is also rapid, it is particularly preferable to manufacture at least two sections for a preform in parallel and simultaneously, and to subsequently combine them to form one component.
According to preferred embodiments, the fiber layers are stored on reels or bobbins, and are delivered to the production process from a stockpiling unit. Continuous production can be ensured as a result.
It is particularly preferable for necessary bobbin changes to take place automatically. However, it is feasible and possible to continuously prefabricate the fiber layers in a special production device or development unit situated upstream of the process.
Dry fiber material, rovings, wovens, non-wovens, fleeces, interwovens or are preferably used as fiber layers. They are subsequently enclosed in a matrix of thermoplastic material. The plastic that is used need not always be applied to the fiber layers. For example, the fiber layers can also be fabricated using fibers sheathed in plastic. In that case, individual fibers or a certain portion of the fibers or every fiber can be sheathed separately. They can be used to manufacture a woven material or the like. It is also feasible to use thermosetting plastics for the matrix. Prepregs are already prepregnated with a binder system.
To prevent any stress in the component, the fiber layers in preferred embodiments are introduced into the process relieved of strain. This strain relief can be controllable and delivers the fiber layers to the production process in an oriented and controlled manner by way of a jockey roller system or levelled rollers, for example.
Particularly preferably, the fiber layers of at least one section can be set only at certain points before the transverse reshaping. This is particularly important for sections having unidirectional fiber layers that cannot be extended in the longitudinal reshaping process. Punctiform setting therefore does not take place in the region of the eventual outer radius in particular, since the fiber layers must remain mobile relative to one another for the longitudinal reshaping.
The thermoplastic materials are preferably activated using a heating device. Infrared radiators are advantageous in that particular case.
Particularly preferably, they can be swivelled and/or rotated in particular. It is thereby possible to prevent the material from overheating if production is delayed. This can also be accomplished by covering the radiator.
Since various applications require different components having various radii, it is provided in preferred embodiments that the radius induced in the section in the longitudinal reshaping is variable. It is also feasible and reasonable to change the radius during the production of a section.
According to preferred embodiments, the sections that are produced are cut directly to the desired length. Production can be interrupted briefly for this purpose, although it is also feasible in particular to provide a displaceable cutting unit which is synchronized with the production process. As a result the sections can also be cut to the desired size without interrupting production.
The sections that are cut to the proper length in this manner are then, particularly preferably, transferred by a handling unit—which can be a robot—to an assembly and compacting unit. The robot can have a gripper arm comprising a vacuum device, for example, by way of which the finished sections are transported. The robot can grip components having a radius of between 1500 and 2500 mm, for example.
The device according to the invention for the continuous manufacture of preforms of fiber reinforced plastic has various regions. At least one stockpiling unit is provided, in which fiber layers can be stored on reels or bobbins. At least one heating unit is provided, by way of which the fiber layers can be heated, using infrared radiators, for example. At least one transverse reshaping unit and at least one longitudinal reshaping unit are also provided. The fiber layers to be processed can be supplied continuously from the stockpiling unit. The fiber layers can be reshaped in the transverse reshaping unit into a section having a predetermined cross section. This section can then be curved in the longitudinal reshaping unit into a predetermined radius.
To enable a binder system to be applied to the fiber layers if pretreated fiber layers such as prepregs are not used, a binder application module is provided according to preferred embodiments. It can be used to apply the binder system locally onto the fiber layers, although the complete fiber layers can also be provided with the binder system. The binder system can be present in powder form, for instance, and can be applied onto the fiber layers using a perforated plate and a rotating carriage. Liquid binder systems which can be applied as an aerosol using a spray head, for instance, are also feasible.
Particularly preferably the device comprises at least one of the following modules: Inductor unit, binder application module, cutting unit, handling unit, and/or assembly device.
The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 a schematic depiction of the device according to the invention, in a perspective side view;
FIG. 2 a principle sketch according to FIG. 1 , in a perspective side view;
FIG. 3 a further principle sketch of the device according to the invention, in a side view;
FIG. 4 a a schematic depiction of the transverse shaping unit;
FIG. 4 b a principle sketch according to FIG. 4 a;
FIG. 5 a a schematic depiction of the longitudinal reshaping unit, in a side view;
FIG. 5 b a schematic depiction of the longitudinal reshaping unit, in a top view;
FIG. 5 c a principle sketch of the longitudinal reshaping unit according to FIG. 5 b;
FIG. 6 a schematic depiction of a binder application module in a perspective side view;
FIG. 7 an LCF section manufactured using the method according to the invention
FIG. 8 a schematically depicted cross section of an LCF section of the type shown in FIG. 7 ; and
FIGS. 9 a - g a schematic depiction of the mode of operation of the assembly/compacting unit, in cross sections.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows an embodiment of a device 1 according to the invention. The system is composed of frames made of standard profiled elements. In selecting which components to use, particular attention is given to ease of replacement, temperature resistance up to at least approximately 200° C., acetone resistance, and very gentle of handling of material during the production process. Furthermore, the entire system can be lubricant-free, and therefore no limits are placed on the material selection.
The framework has a modular design, and the installations for the related functional carriers are located inside the individual frames. As a result, the system can be adapted in an optimal manner to various requirements regarding the preform that is produced, and regarding the installation site.
The system shown in FIG. 1 has a length of 8 m, a width of 2.5 m, and a height of 2 m, for example. The individual modules have a unit height of 625 mm and a unit width of 500 mm. The length of the individual modules varies depending on the unit installed, wherein the modules are provided in a grid arrangement of 125 mm in this case.
The system according to the invention is used to manufacture preforms or structural elements having complex geometries in one continuous process. This is achieved by manufacturing at least two sections in the system and then assembling them to form the complex structural element. To ensure that the process is rapid and continuous, at least two sections, which can have different cross sections, of course, can be manufactured in parallel/simultaneously in the system. This is shown as an example in FIGS. 1-3 using the three production levels 17 , 18 , 19 shown.
The system shown in FIG. 1 has a stockpiling unit 2 containing a total of 10 modules. In this example, each module can accommodate two bobbins 15 having fiber layers 16 . Bobbins are provided for the +/−45° and the 0° layers of the sections. The method of bobbin replacement is designed such that bobbins can be replaced as quickly and in the most user-friendly manner possible. The +/−45° layers are particularly suited for draping, since a longitudinally lying strip can be reshaped into a curve without fibers being stretched or compressed in the inner or outer radius.
In each production level 17 , 18 , 19 , a plurality of fiber layers from different bobbins can be introduced into the production process.
To ensure that material is transported without delay and in a controlled manner, it is advantageous to provide UD portions in the fiber layers. Moreover, the bobbins are advantageously designed to be braked, thereby preventing the fiber layers from being introduced too quickly. For this purpose, the bobbins have a hollow core which is clamped between two displaceable, rotatably supported conical pieces. Braking takes place by way of a spring-loaded frictional element on one of the conical pieces, for example. Other braking systems are feasible, of course, such as magnetic powder or hysteresis brakes.
Every module of the stockpiling unit has at least one rotatable removal device for safely unwinding the fiber layers from the bobbin. Rollers for levelling the material processions are provided at the end of each module of stockpiling device 2 . To ensure that the material is guided in a straight manner during unwinding, insertion rings are used as shoulder rings.
Another possible method for the controlled unrolling of the individual fiber layers from the bobbins is a module which is not depicted in FIGS. 1-3 , the strain relief unit. In that particular case, permanently levelled rollers are disposed at the entrance and the exit of the module. The function of strain relief is performed by rollers disposed therebetween in a displaceable manner on common vertical guides, which function as compensation elements depending on the tensile load. The individual fiber layers are thereby prevented from travelling at different speeds. This module can also be used in addition to the braked rollers.
The next module in FIGS. 1-3 is conveyor unit 3 . It is used to bring the individual fiber layers into their correct orientation. For this purpose, set collars are provided on rotatable rollers, which guide the individual fiber layers in terms of direction and can also specify the desired material width. At the end of this module the fiber layers that are used are combined to form one stack.
In FIGS. 1-3 an additional module is installed in the lowermost level 19 of the system. Inductor unit 4 is required for a special profile property. The device according to the invention, and the method according to the invention are described with reference to a system for manufacturing a special LCF section. This LCF section (preform) 30 is described in greater detail with reference to FIGS. 7 and 8 . A section for this preform has a C shape and comprises unidirectional fiber layers in the two reshaped flange sides. They cannot be extended in a subsequent longitudinal reshaping, i.e. when a curvature is applied to the component. Therefore, the fiber layers for the C-shaped section must not be set completely.
Inductor unit 4 is required for this purpose since it can be used to locally connect the fiber layers. As a result, the individual layers can still become displaced relative to one another in the region of the eventual outer radius. The required inductors are positioned using a pneumatic gripping mechanism.
The module that contains heating unit 5 is used to join the fibers layers still moving loosely on top of one another such that deviations in direction are ruled out in the subsequent transverse reshaping. In the embodiment presented here, each of the sections that are ultimately assembled to form the preform comprises unidirectional fiber layers at least on one side in the ultimate flange region. They can be heated from both sides in heating unit 5 since they are still in the flat position in heating unit 5 . Various heat sources are feasible and possible. However, infrared radiators are used in the embodiment described herein, which heat only the unidirectional layers of the fiber layer stack in the process shown here. The infrared radiators can be swivelled, preferably through an angle of approximately 90°. They can also be swivelled away at any other angle, or they can be tilted away, moved laterally outwardly, or covered by metal plates, for example. Overheating of the fiber layers can therefore be prevented if the system should come to a standstill.
The heated fiber layer stacks are then pressed together using pressure rollers at desired points to form a secure composite structure. The layered structure, which is otherwise still loose, is held in the desired shape using specially shaped guides, thereby also preventing individual layers from sliding off laterally.
The following module, transverse reshaping unit 6 , brings the fiber layer stack into the correct cross section. The detailed mode of operation of this module is described with reference to FIGS. 4 a and 4 b.
The next module is a conveyor unit 7 (see FIG. 3 ). It is responsible for transporting the material within the production process. In the embodiment described, a pair of knurled, stainless steel rollers in the region of the segment of the component conveys the strand through the system. In that particular case, one roller is driven by a frequency-dependent servo gearbox motor, and the other, as a counter-roller, is controlled in a spring-loaded or pneumatic manner. The counter-roller can also be displaced in the vertical axis, thereby enabling the conveyance process to be adjusted such that optimal straight-ahead running and stress-free transfer of the section to the subsequent longitudinal reshaping unit 8 are ensured. The process speed can also be controlled by regulating the motor of the first roller.
Longitudinal reshaping unit 8 is described in detail with reference to FIGS. 5 a - c.
As soon as the sections have been curved in a predetermined manner in longitudinal reshaping unit 8 , they are cut to the desired length in the subsequent module, cutting unit 9 . In the embodiment shown here, the pneumatic feed cylinder is mechanically coupled to the cutoff wheel drive. The cutoff wheel is also pneumatically controlled.
The cutting unit can be disposed on a displacement table so it can be moved to the predetermined points for cutting the sections.
It is possible to stop the continuous process briefly to perform the cutting. However, it is feasible and particularly preferable for the cutting unit to be synchronized with the section feed, so that the production process need not be interrupted. In this case, the cutting unit moves on the displacement table in a synchronized manner with the section feed, thereby enabling the section to also be cut during forward motion.
The final module of the machine is a handling unit 10 . It comprises a positioning device (e.g. a robot) 11 and a handling device (assembly/compacting unit). Robot 11 transfers the individual sections into assembly unit 38 , in which the sections are assembled to form the finished preform.
For transferring, robot 11 uses a robot gripper 14 attached to an arm 13 which can have movable joints. The robot can also stand on a base 15 . Robot gripper 14 has individual gripping elements which have a fixed distance in the longitudinal direction and are adjustable in the transverse direction. It is therefore possible to grip sections having a certain radius of curvature using the holding force of a vacuum. In the embodiment shown here, the radius of curvature can be between 1500 mm and 2500 mm.
FIGS. 4 a and 4 b show an embodiment of reshaping device 6 .
The schematic depiction presented in FIG. 4 a shows various driven and non-driven pressure rollers. Some rollers 21 press vertically onto fiber layers 16 . Other rollers 22 press fiber layers 16 around a CNC-machined mold core 20 . Rollers 23 are also provided at a 90° angle relative to the original fiber layers. Rollers 21 , 22 , 23 can have a shape that is convex, concave, or straight. It is also possible in particular for all rollers to be adjustable into certain contact angles. All shaping elements and all conveying elements used in the system are made of stainless steel material.
FIG. 4 b shows a similar reshaping device 6 in a schematic depiction.
FIGS. 5 a - c show embodiments according to the invention of longitudinal reshaping unit 7 . FIG. 5 a shows a module having a longitudinal reshaping device 7 , in a perspective view from the side.
Longitudinal reshaping unit 7 is shown from above in FIG. 5 b . Radiant heaters 24 can also be assigned to longitudinal reshaping unit 7 . They can also be designed to be displaceable, swivellable, or tiltable, to prevent overheating. In this case as well, shielding can be used to keep heat away from the material. Cooling also takes place in this module. It may be accelerated by introducing cold air.
In the embodiment described here, a toothed belt unit conveys the section through longitudinal reshaping unit 7 . The section moves over reshaping and guiding plates 25 which, in this embodiment, can be brought into a certain radius by way of a plunger 26 which can be displaced by a spindle 27 . Spindle 27 can be used to change a specified radius during production as well, and therefore a different radius can be formed along a section.
Flexible conveyor belts, which in this embodiment can adapt to the radii of curvature of the section in the range of 1500 mm to 2500 mm, grip a flange of the section on both sides. Other radii are also feasible and possible, of course. The parallel guidance also results in a large working region for set up when the system is being started up.
FIG. 6 shows a binder application module 28 according to the invention, in a perspective side view. In this module, fiber layers 16 can be provided with a binder system completely or only locally. For this purpose, a rotating carriage 29 , to the underside of which a perforated plate is attached, is used to apply a powdery binder to fiber layers 16 passing through.
A shaft comprising guide vanes installed on the longitudinal side is supported in rotating carriage 29 and enables the vanes to rotate when the shaft is rotated, and delivers a consistent quantity of the binder onto the perforated plate. The rotational speed of rotating carriage 29 is matched to the feed rate of fiber layers 16 , thereby ensuring that a defined quantity of the powdered binder drops through the perforated plate onto fiber layers 16 .
To bond the binder to the fiber layers, radiant heaters, in particular infrared radiators 24 in this case, are assigned to binder application module 28 .
FIGS. 7 and 8 show a preform 30 that can be manufactured using an embodiment according to the invention. FIG. 7 shows a schematic depiction with lateral surfaces 32 , 33 , 34 , and horizontal surface 31 .
The special layered structure of this structural section is shown in a section in FIG. 8 . In that particular case, three manufactured sections 35 , 36 , 37 are assembled in an assembly device 38 (see FIG. 9 ). Two sections, 35 and 36 , have an S shape, and one section 37 has a C shape. Large S section 35 lies over small S section 36 and C section 37 , and forms horizontal surface 21 . Lateral surface 34 is composed of large and small S sections 35 , 36 , respectively, lateral surface 33 is composed of small S section 36 and C section 37 , and lateral surface 32 is composed of large S section 35 and C section 37 .
By connecting the three individual sections 35 , 36 , 37 , a highly complex and dimensionally stable structural component is obtained.
FIGS. 9 a to 9 g show the assembly of a preform 30 (LCF section), according to the invention, out of three sections 35 , 36 , 37 .
An assembly unit 38 having a base plate 42 and three rigid metal molds 39 , 40 , 41 is provided for this purpose. Metal mold 39 is securely connected to base plate 42 . The three sections are now inserted by robot 11 one after the other into assembly unit 38 . First, C section 37 is placed onto metal mold 39 ( FIG. 9 a ). Next, small S section 36 is placed onto metal mold 40 . Metal mold 40 can be displaced on the base plate and is slid directly against the C section on metal block 40 ( FIG. 9 b, c ).
Next, large S section 35 is placed onto the two sections ( FIG. 9 d ). Metal mold 41 , which is designed as a displaceable lever, is now moved next to sections 35 , 36 , 37 and folded down to secure sections 35 , 36 , 37 ( FIGS. 9 e, f ).
All metal blocks 39 , 40 , 41 are equipped with heating cartridges and activate the binder in the fiber layers, thereby joining the sections to form a preform. A vacuum diaphragm 43 provides the required process pressure ( FIG. 9 g ).
The compacting carried out in assembly unit 38 minimizes the set-up time of the actual RTM curing device.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions and methods differing from the types described above.
While the invention has been illustrated and described as embodied in a method and device for manufacturing preforms of fiber reinfoced plastic, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.
What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.
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In a device and method for manufacturing preforms of fiber reinforced plastic, in a first step, continuously supplied fiber layers are laterally reshaped in a predetermined manner, and the section that is obtained is curved longitudinally in a specific manner in a second step.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a screw groove type vacuum pump, and a complex pump and a vacuum pump system both of which include the screw groove type vacuum pump. More specifically, the present invention relates to a screw groove type vacuum pump, a complex pump and a vacuum pump system with which excellent exhaust speed can be attained.
2. Description of the Related Art
Screw groove type vacuum pumps have conventionally been well known. Any of these screw groove type vacuum pumps is provided with a rotor member that rotates and a stator member fixedly arranged so as to be coaxial with the rotor member, and has a screw groove formed on one of a circumferential wall of the rotor member and an opposite wall of the stator member which is opposite to the circumferential wall. The rotor member is rotated to introduce gas from an inlet port into the screw groove and to then transfer the gas along the screw groove, thereby discharging the gas through an outlet port.
In the screw groove type vacuum pump as such, conventionally, a screw sealing technique or the like is applied and the screw groove is designed so as to be rather shallow in order to efficiently transfer with the rotation of the rotor member gas molecules whose pressure is of a viscous flow region while utilizing the viscosity, and to thereby prevent the backward-flow from the outlet port side to the inlet port side.
However, conventional screw groove type vacuum pumps as described above have a problem of slow exhaust speed, for the average free path of gas molecules is large for gas in a molecule flow region and hence it is difficult to introduce the gas into the screw groove.
There has been proposed as a technique for improving the gas exhaust speed a screw groove type vacuum pump in which the screw groove at the inlet port is set deep and the depth of the screw groove is sharply reduced from thereon. In this screw groove type vacuum pump, the intake area of gas that is taken from the inlet port into the screw groove is large making it easy to introduce the gas in the molecule flow region into the screw groove.
On the side downstream of the inlet port, however, the pressure of the gas to be transferred through the screw groove is of an intermediate flow region between the molecule flow region and the viscous flow region, and the average free path of gas molecules is relatively large. For that reason, the gas molecules taken in are reflected by the bottom of the screw groove, or the like, which means that a sufficient exhaust speed cannot be obtained by merely setting the screw groove deeper at the inlet port.
The present inventors have found that, in a screw groove type vacuum pump, the pressure of the gas to be transferred through the screwed groove maintains the pressure of the intermediate flow region between the molecule flow region and the viscous flow region downstream of the inlet port until the gas reaches a certain depth of the pump in the axial direction, and that setting the flow path wider at this certain depth and securing the sealing from thereon result in prevention of reflection and backward flow of gas molecules, prevention of degradation of sealing, improved gas exhaust efficiency and excellent exhaust speed.
SUMMARY OF THE INVENTION
The present invention has been made on the basis of the findings as above, and an object of the present invention is therefore to provide a screw groove type vacuum pump, a complex vacuum pump and a vacuum pump system with which excellent exhaust speed can be attained.
In order to achieve the above object, the present invention provides a screw groove type vacuum pump comprising: a rotor member that rotates; a stator member fixedly arranged so as to be coaxial with the rotor member and having an opposite wall that is opposite to a circumferential wall of the rotor member; an inlet port for introducing gas into a space between the circumferential wall of the rotor member and the opposite wall of the stator member; and an outlet port for discharging the gas from the space between the circumferential wall of the rotor member and the opposite wall of the stator member, in which: a screw groove for transferring the gas from the inlet port with the rotation of the rotor member is formed on one of the circumferential wall of the rotor member and the opposite wall of the stator member; the depth of the screw groove at the nearest point to the inlet port is 20 mm or more, or is equal to or larger than ¼ the diameter, including the screw groove, of one of the circumferential wall of the rotor member and the opposite wall of the stator member, the depth of the screw groove is decreased toward the outlet port side from the inlet port side, and the depth of the screw groove in a region defined by the inlet port and a point on the rotor member which is 40 mm in the axial direction is 80% or more of the depth at the nearest point to the inlet port; and the slant of the screw groove with respect to the radial direction of the rotor member is decreased toward the outlet port side from the inlet port side, and maintains to be 80% or more of the slant at the inlet port until the thread reaches a point on the rotor member which is at least 40 mm in the axial direction.
According to the above screw groove type vacuum pump of the present invention, the depth of the screw groove may be decreased toward the outlet port side, which is downstream of a region defined by the inlet port and the point on the rotor member which is 40 mm in the axial direction, in proportion to the distance in the axial direction. This makes it possible to transfer gas in a viscous flow region with tight sealing.
The slant of the screw groove may be decreased toward the outlet port side, which is downstream of a region defined by the inlet port and the point on the rotor member which is 40 mm in the axial direction, in proportion to the distance in the axial direction. This makes it possible to transfer gas in the viscous flow region with tight sealing.
The slant of the screw groove may be decreased toward the outlet port side, which is downstream of a region defined by the inlet port and the point on the rotor member which is 40 mm in the axial direction, in logarithmic proportion to the distance in the axial direction. This makes it possible to transfer gas in the viscous flow region with tight sealing.
In order to achieve the above object, the present invention also provides a complex vacuum pump including the above screw groove type vacuum pump of the present invention.
In order to achieve the above object, the present invention also provides a vacuum pump system comprising the above screw groove type vacuum pump of the present invention and an auxiliary pump for taking in gas discharged through the outlet port of the screw groove type vacuum pump.
In order to achieve the above object, the present invention also provides a vacuum pump system comprising the above screw groove type vacuum pump of the present invention and an auxiliary pump for taking in gas discharged through the outlet port of the screw groove type vacuum pump that is included in the complex vacuum pump.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a sectional view showing the entire structure of a screw groove type vacuum pump according to an embodiment of the present invention;
FIG. 2 is a side view showing a rotor body of the screw groove type vacuum pump in FIG. 1;
FIG. 3 is an internal side view showing a state where a rotor body 61 of the screw groove type vacuum pump in FIG. 1 is attached to a rotor shaft; and
FIG. 4 is a graph showing the relationship between the pressure and the exhaust speed in the screw groove type vacuum pump in FIG. 1, in comparison with a conventional screw groove type vacuum pump.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, a description will be given in detail of preferred embodiments of the present invention with reference to FIGS. 1 to 4 .
FIG. 1 is a sectional view showing the entire structure of a screw groove type vacuum pump according to an embodiment of the present invention.
The screw groove type vacuum pump according to this embodiment is comprised of, as shown in FIG. 1, a rotor shaft 18 shaped like a column, a rotor 60 as a rotor member that is fixedly arranged on the rotor shaft 18 and rotates together with the rotor shaft 18 , and a casing or an exterior member 10 and a stator 70 which serve as a stator member.
The exterior member 10 has a cylindrical shape whose diameter does not vary over the entire length in the axial direction, and the rotor shaft 18 is coaxially arranged in the center of the exterior member 10 .
The exterior member 10 has at its upper end a flange 11 elongated outward in the radial direction. The flange 11 has bolt holes 11 a drilled therein in a direction parallel to the axis. This flange 11 is fastened to, for example, an apparatus for manufacturing semiconductors with bolts or the like to connect an inlet port 16 formed inside the flange 11 to an outlet port of a vessel, e.g., a chamber, so that the interior of the vessel is communicated with the interior of the exterior member 10 .
The rotor shaft 18 is supported by a magnetic bearing 20 with a magnetic force, and is rotated with a driving force transmitted from a motor 30 . The stator 70 is provided with a tubular portion 71 that surrounds the rotor shaft 18 and is shaped like a tube and a base portion 72 to which the tubular portion 71 is fixed at an upper part.
The magnetic bearing 20 is a 5-axes-control type magnetic bearing, and is provided with: radial electromagnets 21 , 24 for generating a magnetic force in the radial direction of the rotor shaft 18 in the vicinity of the upper and lower ends of the rotor shaft 18 ; radial sensors 22 , 26 for detecting the position of the rotor shaft 18 in the radial direction; axial electromagnets 32 , 34 for generating a magnetic force in the axial direction of the rotor shaft 18 ; a metal disc 31 upon which the magnetic force in the axial direction, generated by the axial electromagnets 32 , 34 , acts; and an axial sensor 36 for detecting the position of the rotor shaft 18 in the axial direction.
The radial electromagnets 21 , 24 each include two pairs of electromagnets arranged on the tubular portion 71 of the stator 70 such that one pair is perpendicular to the other pair. The electromagnets in each pair are arranged so as to face one another with the rotor shaft 18 interposed therebetween. An excitation current is supplied to these radial electromagnets 21 , 24 to float the rotor shaft 18 with a magnetic force.
Outside the radial electromagnets 21 , 24 in the thrust direction, two paris of the radial sensors 22 and two pairs of the radial sensors 26 are arranged on the tubular portion 71 of the stator 70 such that the two pairs of the radial sensors 22 and the two pairs of radial sensors 26 are arranged with one pair being perpendicular to the other pair, corresponding to the radial electromagnets 21 , 24 . Two sensors in each sensor pair face one another with the rotor shaft 18 interposed therebetween. The control of the excitation current supplied to the radial electromagnets 21 , 24 is made, when the shaft is floated with a magnetic force, in response to position detection signals sent from the radial sensors 22 , 26 , to thereby keep the rotor shaft 18 at a predetermined position in the radial direction.
The metal disc 31 made of a magnetic member and shaped like a disc is fixed to a lower of the rotor shaft 18 . A pair of the axial electromagnets 32 and a pair of the axial electromagnets 34 are arranged on the base portion 72 of the stator 70 such that the electromagnets 32 face the, electromagnets 34 with the metal disc 31 interposed therebetween. The axial sensor 36 is arranged on the base portion 72 of the stator 70 while being opposed to the lower end of the rotor shaft 18 .
An excitation current flowing through the axial electromagnets 32 , 34 is controlled in response to a position detection signal sent from the axial sensor 36 , to thereby keep the rotor shaft 18 at a predetermined position in the axial direction.
It is possible for the vacuum pump to be driven in a clean environment, for the employment of the magnetic bearing 20 eliminates any mechanical contacts to produce no dust, and dispenses the pump of oils such as a sealing oil to generate no gas. The screw groove type vacuum pump according to this embodiment is thus suitable for an application in which a high cleanness is required as in manufacture of semiconductors.
The screw groove type vacuum pump according to this embodiment also has touch down bearings 38 , 39 arranged on an upper part and on a lower part of the rotor shaft 18 , respectively.
Usually, the rotor unit comprising the rotor shaft 18 and the parts attached to the shaft is, while being rotated by the motor 30 , axially supported by the magnetic bearing 20 without coming into contact with the bearing. The touch down bearings 38 , 39 are bearings for protecting the entire pump by axially supporting the rotor unit instead of the magnetic bearing 20 when the touch down takes place.
Accordingly, the touch down bearings 38 , 39 are arranged so that their inner rings do not come into contact with the rotor shaft 18 .
The motor 30 is arranged almost in the middle between the radial sensors 22 and 26 , inside the exterior member 10 , in the axial direction of the rotor shaft 18 . The motor 30 is energized to rotate the rotor shaft 18 as well as the rotor 60 that is attached to the shaft.
The rotor 60 is comprised of a rotor body 61 having a sectional shape like an inverted letter U and arranged on the outer periphery of the rotor shaft 18 , and a screw thread 63 elongated outward from the outer peripheral surface of the rotor body 61 . This rotor body 61 is attached to the top of the rotor shaft 18 with bolts 19 .
FIG. 2 is a side view of the rotor body 61 , and FIG. 3 is an internal side view showing a state in which the rotor body 61 is attached to the rotor shaft 18 .
As shown in FIG. 2, the screw thread 63 of the rotor 60 is helically formed of plural threads so as to be coaxial with the axis of the rotor body 61 on the outer peripheral surface of the rotor body 61 . The space between the threads of the screw thread 63 is a screw groove 62 . As shown in FIG. 3, the rotor 60 is fixed to the rotor shaft 18 , and the edge face of the screw thread 63 faces the inner circumferential wall of the exterior member 10 with a gap that may be deemed as invariable over the entire length of the rotor body.
The screw groove 62 is communicated with the inlet port 16 so that gas from the chamber is introduced into the screw groove 62 . The screw groove 62 has at the nearest point to the inlet port 16 a depth D (distance from the free edge face of the screw thread 63 down to the outer peripheral surface of the rotor body 61 ) of 20 mm or more. The slant θ with respect to the radial direction of the rotor 60 (an angle of elevation) of the screw groove 62 is 20 to 40° at the nearest point to the inlet port 16 .
The diameter of the rotor body 61 is increased downstream (toward the outlet port 17 side), as the distance from the inlet port 16 is increased, protruding to the inner circumferential wall of the exterior member 10 . The screw groove 62 is adapted to this increase in diameter of the rotor body 61 and the depth D of the groove is made shallow. The slope of the screw thread 63 with respect to the radial direction becomes gentle as it distances itself from the inlet port 16 and approaches the outlet port 17 , and the angle of elevation θ of the screw groove 62 accordingly takes a smaller value.
From the inlet port 16 to a point on the rotor body 61 which is 40 mm in the axial direction (in a range indicated by reference symbol B in the drawing), the depth D and the angle of elevation θ of the screw groove 62 are gently and continuously decreased but maintain to be 80% or more of the depth D and the angle of elevation θ at the inlet port 16 . The ratio of a distance d from the bottom of the screw groove 62 to the outer circumferential wall of the exterior member 10 to a distance c from the edge of the screw thread 63 to the inner circumferential wall of the exterior member 10 (clearance ratio: d/c in FIG. 1) is set to 50 or more.
On the side downstream of the region defined by the inlet port 16 and the point on the rotor body 61 which is 40 mm in the axial direction (region indicated by B in the drawing), the depth D and the angle of elevation θ of the screw groove 62 are continuously and gradually reduced as the distance from the outlet port 17 is decreased. The degree of this reduction is in proportion to the distance in the axial direction.
Given the distance in the axial direction between predetermined positions P and Q of the screw groove as Lv, and the depth of the screw groove 62 at the respective positions as Dp, Dq, the following expression is satisfied when the degree of reduction in the depth D of the screw groove 62 is in proportion to the distance in the axial direction:
Dp−Dq=k·Lv [Numerical Expression 1]
where k is a constant that is a plus if P is closer to the inlet port than Q is and which is a minus if P is closer to the outlet port than Q is).
Therefore when, for example, the depth of the screw groove at the nearest point to the outlet port side in the region B is T mm and the depth D of the screw groove 62 at a point 1 cm in the axial direction down there is reduced therefrom by t mm, i.e., (T−t) mm, the depth D of the screw groove at a point 3 cm in the axial direction down the nearest point to the outlet port side in the region B is reduced by 3t mm, i.e., (T−3t) mm.
Given the distance in the axial direction between predetermined positions P and Q of the screw groove as Lv, and the angle of elevation of the screw groove 62 at the respective positions as θp, θq, the following expression is satisfied when the degree of reduction in the angle of elevation θ of the screw groove 62 is in proportion to the distance in the axial direction:
θp−θq=k·Lv [Numerical Expression 2]
where k is a constant that is a plus if P is closer to the inlet port than Q is and which is a minus if P is closer to the outlet port than Q is).
Therefore when, for example, the angle of elevation of the screw groove at the nearest point to the outlet port side in the region B is S° and the angle of elevation of the screw groove 62 at a point 1 cm in the axial direction down there is reduced therefrom by s°, i.e., (S−s)°, the angle of elevation θ of the screw groove at a point 3 cm in the axial direction down the nearest point to the outlet port side in the region B is reduced by 3 so, i.e., (S−3s)°.
The screw groove 62 is communicated with the outlet port 17 arranged in a lower part of the exterior member 10 , so that the gas transferred through the screw groove 62 is discharged from the outlet port 17 . At the outlet port 17 , the clearance ratio d/c of the screw groove 62 is 20 or less and the angle of elevation thereof is 10 to 20°.
In the vacuum pump as such, the rotor shaft 18 is rotated at a high speed with the motor 30 to thereby rotate at a high speed the rotor 60 as well. This has process gas or the like in a chamber 90 transferred through the inlet port 16 of the screw groove type vacuum pump and through the screw groove 62 to be discharged from an outlet port 52 .
At this point, the pressure in the screw groove 62 is about 0.1 Pa or less in the region defined by the inlet port 16 and the point on the rotor 60 which is 40 mm in the axial direction (the region B), and the depth D and the angle of elevation θ of the screw groove 62 are both set to rather large values. The gas molecules are thus captured at the screw thread 63 efficiently and transferred to the outlet port 17 side without being reflected or flowing backwards.
On the side downstream of the region defined by the inlet port 16 and the point on the rotor 60 which is 40 mm in the axial direction, the pressure in the screw groove 62 is of the viscous flow region. The screw groove here changes sharply and markedly to a shallow groove and comes to have a small angle of elevation θ, which leads to efficient transfer of the captured gas molecules by viscosity to the outlet port 17 while obtaining excellent sealing.
According to this embodiment, the depth D of the screw groove 62 is 20 mm or more and the angle of elevation θ thereof is 20 to 40° at the end on the inlet port 16 side. The intake area of the gas taken in from the inlet port 16 to the screw groove 62 is therefore large, making it easy to introduce the gas into the screw groove.
According to this embodiment, in the region defined by the inlet port 16 and the point on the rotor 60 which is 40 mm in the axial direction (region B) where the pressure is about 0.1 Pa or less, the screw groove 62 has a depth D of 80% or more of the depth at the end on the inlet port 16 side and has a clearance ratio d/c of 50 or more, which together provide the groove 62 with a sufficient depth. In addition, the angle of elevation θ of the groove 62 in the region B is 80% or more of the angle at the end on the inlet port 16 side. Therefore, the gas molecules in the intermediate flow region are captured well at the screw thread 63 , and quickly transferred to the outlet port 17 side without flowing backwards.
According to this embodiment, on the side downstream of the region defined by the inlet port 16 and the point on the rotor 60 which is 40 mm in the axial direction, the screw groove changes sharply and markedly to a shallow groove and comes to have a small angle of elevation θ, which leads to efficient transfer of the gas molecules in the molecule flow region by viscosity to the outlet port 17 while obtaining excellent sealing.
According to this embodiment, at the end of the outlet port 17 , the depth D of the screw groove 62 is sufficiently shallow, the clearance ratio d/c is 20 or less, and the angle of elevation θ thereof is as sufficiently small as 10 to 20°. The back pressure dependency is thus small, which also is a contributor to obtainment of excellent gas exhaust speed.
FIG. 4 is a graph showing the relationship between the pressure and the exhaust speed in the screw groove type vacuum pump according to this embodiment, in comparison with a conventional screw groove type vacuum pump, in which the line A is associated with the screw groove type vacuum pump of this embodiment and the line B is associated with the screw groove type vacuum pump in prior art.
As shown in FIG. 4, in the screw groove type vacuum pump of this embodiment, the depth D and the angle of elevation θ of the screw groove 62 are set to large values in the molecule flow region and the intermediate flow region where the pressure in the screw a groove 62 is 0.1 Pa or less to thereby take in many gas molecules, introduce the gas into the screw groove without reflecting the gas or causing the backward flow of the gas, and transfer the gas molecules to the viscous flow region. Then in the viscous flow region, the depth D and the angle of elevation θ of the screw groove 62 are set to small values to secure the sealing, thereby minimizing the deterioration of the sealing and efficiently transferring the gas molecules from the intermediate flow region. Therefore, an exhaust speed better than in the screw groove type vacuum pump of the prior art can be obtained in any region of the molecule flow region, the intermediate flow region, and the viscous flow region.
The screw groove type vacuum pump structured as above is employed in an embodiment of a vacuum pump system of the present invention in which an auxiliary pump is connected to the outlet port 17 .
In the vacuum pump system according to this embodiment, the auxiliary pump may be a well-known one and, as in prior art, is connected to the outlet port 17 of the screw groove type vacuum pump.
In the vacuum pump system according to this embodiment, employment of the screw groove type vacuum pump according to the embodiment previously described makes it possible to fully utilize the capacity of the conventional auxiliary pump, so that the pressure on the outlet port 17 side is adjusted and the discharge capacity of the system is further improved.
The screw groove type vacuum pump of the present invention and the vacuum pump system of the present invention are not limited to the embodiments above, and may be modified suitably as long as the modification does not depart from the spirit of the present invention.
For instance, the depth D of the screw groove 62 of the screw groove type vacuum pump at the end on the inlet port 16 side, which is 20 mm or more in the previous embodiments, may be less than 20 mm. Because the same action and effect as in the previous embodiment can be obtained if the depth D is ¼ or more of the diameter of, including the screw groove 62 , the circumferential wall of the rotor on which the screw groove 62 is formed.
The depth D and the angle of elevation θ of the screw groove 62 are both reduced gradually at any point from the end on the inlet port 16 side to the end on the outlet port 17 side in the previous embodiment. However, the depth D and the angle of elevation θ may remain the same at some points along the path, provided that the depth and the angle are not increased at a downstream point from an upstream point. For instance, in the region defined by the inlet port 16 and the point on the rotor 60 which is 40 mm in the axial direction (region B), one of or both of the depth D and the angle of elevation θ may not be reduced but may keep the same value as the depth D and the angle of elevation θ at the end of the inlet port.
In the previous embodiment, the angle of elevation θ of the screw groove 62 is continuously reduced toward the outlet port 17 side in proportion to the distance in the axial direction on the side downstream of the region defined by the inlet port 16 and the point on the rotor body 61 which is 40 mm in the axial direction (region B in the drawing). However, the degree of this reduction may be in logarithmic proportion to the distance in the axial direction, instead. If the degree of reduction in the angle of elevation θ of the screw groove 62 is in logarithmic proportion to the distance in the axial direction, the angle of elevation θ is sharply reduced as the screw groove approaches the outlet port 17 , avoiding the influence of the back pressure even more effectively.
Though the screw groove 62 is formed on the rotor 60 in the previous embodiment, the groove may be formed on the surface of the exterior member 10 which is opposite to the rotor.
In the screw groove type vacuum pump according to the previous embodiment, the screw groove 62 is formed on the outer peripheral surface of the rotor 60 and the gas is transferred through a space between the screw groove 62 and an outer tube member that is a stator member arranged outside the groove. Alternatively, for example, an outer rotor type motor may be used to arrange the stator member inside the rotor 60 and form the screw groove 62 on the inner peripheral surface of the rotor 60 or on the outer peripheral surface of the stator member.
The same effect can be obtained in a complex vacuum pump in which the screw groove type vacuum pump according to the previous embodiment or according to the modified examples described above and a vacuum pump other than the screw groove type vacuum pump, such as a turbomolecular pump or a centrifugal flow type pump, are connected. The same effect also can be obtained in a vacuum pump system in which an auxiliary pump is provided in addition to this complex vacuum pump.
As has been described, according to the screw groove type vacuum pump, the complex vacuum pump and the vacuum pump system of the present invention, the intake area of the gas that is taken from the inlet port into the screw groove is large and the gas is hardly reflected, so that the gas is efficiently introduced from the inlet port into the screw groove and the introduced gas is transferred to the outlet port with excellent sealing properties. A high exhaust speed thus can be obtained.
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A screw groove-type pump has a rotor member mounted for undergoing rotation, a stator member arranged so as to be coaxial with the rotor member and having a peripheral wall disposed opposite to and spaced-apart from a circumferential wall of the rotor member, an inlet port for introducing gas into a space between the circumferential wall of the rotor member and the peripheral wall of the stator member, and an outlet port for discharging gas introduced into the space between the circumferential wall of the rotor member and the peripheral wall of the stator member. A screw groove is formed on one of the circumferential wall of the rotor member and the peripheral wall of the stator member for transferring gas introduced into the inlet port through the space between the circumferential wall of the rotor member and the peripheral wall of the stator member and to the outlet port during rotation of the rotor member. The depth of the screw groove at a point thereof which is nearest the inlet port is equal to or larger than ¼ the diameter of one of the circumferential wall of the rotor member and the peripheral wall of the stator member. An angle of elevation of the screw groove with respect to a radial axis of the rotor member decreases toward the outlet port from the inlet port.
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BACKGROUND OF THE INVENTION
The present invention generally relates to material displacement apparatus and, in a preferred embodiment thereof, more particularly relates to apparatus for releasably coupling a replaceable excavation tooth point to an associated adapter nose structure.
A variety of types of material displacement apparatus are provided with replaceable portions that are removably carried by larger base structures and come into abrasive, wearing contact with the material being displaced. For example, excavating tooth assemblies provided on digging equipment such as excavating buckets or the like typically comprise a relatively massive adapter portion which is suitably anchored to the forward bucket lip and has a reduced cross-section, forwardly projecting nose portion, and a replaceable tooth point having formed through a rear end thereof a pocket opening that releasably receives the adapter nose. To captively retain the point on the adapter nose, aligned transverse openings are formed through these interengageable elements adjacent the rear end of the point, and a suitable connector structure is driven into and forcibly retained within the aligned openings to releasably anchor the replaceable tooth point on its associated adapter nose portion.
Connector structures adapted to be driven into the aligned tooth point and adapter nose openings typically come in two primary forms—(1) wedge and spool connector sets, and (2) flex pin connectors. A wedge and spool connector set comprises a tapered spool portion which is initially placed in the aligned tooth and adapter nose openings, and a tapered wedge portion which is subsequently driven into the openings, against the spool portion, to jam the structure in place within the openings in a manner exerting high rigid retention forces on the interior opening surfaces and press the nose portion into a tight fitting engagement with the tooth pocket.
Very high drive-in and knock-out forces are required to insert and later remove the steel wedge and typically require a two man effort to pound the wedge in and out—one man holding a removal tool against an end of the wedge, and the other man pounding on the removal tool with a sledge hammer. This creates a safety hazard due to the possibility of flying metal slivers and/or the second man hitting the first man instead of the removal tool with the sledge hammer. Additionally, wear between the tooth/adapter nose surface interface during excavation use of the tooth tends to loosen the tight fit of the wedge/spool structure within the tooth and adapter nose openings, thereby permitting the wedge/spool structure to fall out of the openings and thus permitting the tooth to fall off the adapter nose.
Flex pin structures typically comprise two elongated metal members held in a spaced apart, side-by-side orientation by an elastomeric material bonded therebetween. The flex pin structure is longitudinally driven into the tooth and adapter nose openings to cause the elastomeric material to be compressed and resiliently force the metal members against the nose and tooth openings to retain the connector structure in place within the openings and resiliently press the adapter nose portion into tight fitting engagement with the interior surface of the tooth socket.
Flex pins also have their disadvantages. For example, compared to wedge/spool structures they have a substantially lower in-place retention force. Additionally, reverse loading on the tooth creates a gap in the tooth and adapter nose openings through which dirt can enter the tooth pocket and undesirably accelerate wear at the tooth/adapter nose surface interface which correspondingly loosens the connector retention force. Further, the elastomeric materials typically used in flex pin connectors are unavoidably subject to deterioration from hot, cold and acidic operating environments. Moreover, in both wedge-and-spool and flex pin connectors relatively precise manufacturing dimensional tolerances are required in the tooth point and adapter nose portions to accommodate the installation of their associated connector structures.
Proposed solutions to these various connector-based problems, limitations and disadvantages in excavation tooth point/adapter assemblies have included wedge-shaped connector members which are inserted into the aligned point and adapter nose openings having complementarily tapered configurations, with the inserted connector being resiliently biased in a longitudinal “tightening” direction relative to the point and adapter nose by a lock member carried by the connector member. The lock member is rotatably and sealingly received within an end of the connector member, bears against a portion of the tooth point, and is spring-biased longitudinally outwardly from the connector member. An example of this wedge-shaped type of connector structure is illustrated and described in U.S. Pat. No. 6,108,950 to Ruvang.
This particular wedge-shaped type of connector structure at least substantially reduces various of the problems, limitations and disadvantages discussed above in conjunction with conventional flex pins and wedge and spool connector sets. However, it has several limitations of its own. For example, due to the wedge shape of the connector member, excavating loading forces exerted on the connector member can generate a substantial axial force component on the connector member which can, in certain instances, damage the lock member and permit the connector member to be expelled from the tooth point and adapter nose openings. Moreover, because the spring-biased lock member is permitted to move into and out of the connector member, dirt may be drawn into the interior connector/lock member surface interface area and substantially degrade the seal carried by the lock member. Further, with the lock member maintained in its unlocking position for extended periods of time (for example when the overall connector structure is being stored prior to use), an elastomeric portion of the lock member detent portion is maintained in compression and can obtain an undesirable compression set.
It can be seen from the foregoing that it would be desirable to provide improved excavating tooth connector apparatus that eliminates or at least substantially reduces the above-mentioned problems, limitations and disadvantages associated with conventional excavating tooth and other material displacement equipment connector apparatus of the general type described above.
SUMMARY OF THE INVENTION
In carrying out principles of the present invention, in accordance with a representatively illustrated embodiment thereof, a specially designed connector assembly is used to releasably retain an excavating wear member, representatively a replaceable tooth point, on a support structure, representatively an adapter nose.
The connector assembly, in the representatively illustrated embodiment thereof, includes (1) an elongated flat connector member extending along a longitudinal axis and having a flat exterior side peripheral portion extending between opposite first and second ends and circumscribing the longitudinal axis in a parallel relationship therewith, and (2) a locking member rotatable received in the first connector member end and being rotatable between locking and unlocking positions in which a locking tab portion of the locking member respectively projects laterally outwardly beyond the connector member side surface periphery, and an unlocking position in which the locking tab does not project laterally outwardly beyond the connector member side surface periphery.
A detent structure within the interior of the connector member releasably retains the locking member in either selected one of its locking and unlocking positions. The locking member has no resilient force exerted thereon parallel to the length of the connector member in either of the locking and unlocking positions of the lock member, and the detent structure substantially prevents any appreciable relative movement of the lock member and the connector member parallel to the longitudinal axis of the connector member when the lock member is in either of its locking and unlocking positions. The detent structure representatively includes a rigid detent member carried by the lock member and having an associate resilient portion, and first and second circumferentially spaced detent openings disposed within the connector member interior for respectively receiving the detent member when the lock member is in its locking and unlocking positions. The resilient portion of the detent structure is in an essentially relaxed state when the lock member is in either of its locking and unlocking positions.
With the tooth point telescoped onto the adapter nose, side wall connector openings in the tooth point aligned with a connector opening transversely extending through the adapter nose, and the lock member in its unlocking position, the connector assembly is inserted into the connector openings until the opposite ends of the connector member are disposed in the opposite tooth point connector openings to thereby block forward removal of the tooth point from the adapter nose. The locking member is then rotated to its locking position. After this is done, abutment surface areas within the interior of the tooth point/adapter assembly prevent the installed connector assembly from moving outwardly through either tooth point connector opening. Representatively, these abutment surface areas include (1) a first abutment surface defined in an interior side surface recess of a first one of the two tooth point side wall connector openings into which the locking tab is moved when rotated to its locking position, the first abutment surface blocking the locking tab, and thus the entire connector assembly, from moving outwardly through the first tooth point connector opening, and (2) a second abutment surface formed on a side wall portion of the tooth point which extends into the second tooth point connector opening, reduces its cross-sectional area relative to that of the first tooth point connector opening, and blocks the installed connector assembly from moving outwardly through the second tooth point side wall connector opening.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinally foreshortened, horizontally directed cross-sectional view, partly in elevation, through an excavating tooth point/adapter assembly incorporating therein a specially designed rotatably locking connector structure embodying principles of the present invention;
FIG. 2 is a cross-sectional view, partly in elevation, through the assembly taken along line 2 — 2 of FIG. 1;
FIG. 3 is a top end elevational view of the connector structure with a rotatable locking portion thereof being in its locking position shown in FIG. 2;
FIG. 4 is a top end elevational view of the connector structure with its rotatable locking portion in its unlocking position; and
FIG. 5 is an enlarged scale schematic partial cross-sectional view through the connector structure taken along line 5 — 5 of FIG. 2 .
DETAILED DESCRIPTION
As cross-sectionally illustrated in longitudinally foreshortened form in FIGS. 1 and 2, in an illustrated embodiment thereof, this invention provides an excavating tooth point/adapter assembly 10 that includes a wear member in the form of an elongated hollow replaceable tooth point 12 extending in a front-to-rear direction along a longitudinal axis 14 and having front and rear portions 16 and 18 ; a support structure in the form of an adapter 20 having a base portion 22 from which a smaller cross-section nose portion 24 forwardly projects; and a specially designed rotatably lockable connector assembly 26 used to releasably retain the tooth point 12 on the adapter nose 24 as subsequently described herein.
Representatively, the tooth point 12 and adapter 20 have configurations similar to the tooth point and associated adapter illustrated and described in copending U.S. application Ser. No. 09/843,681 (now U.S. Pat. No. 6,564,482) filed on Apr. 27, 2001 and assigned to the same assignee as the assignee of the present invention. However, the tooth point 12 and the adapter 20 could have a wide variety of alternate shapes without departing from principles of the present invention. Additionally, while the present invention is illustrated and described herein as being used in conjunction with an adapter as a representative support structure and a tooth point as a representative wear member carried by the support structure, it will be readily appreciated by those of ordinary skill in this particular art that different types of support structures and associated wear members could be utilized without departing from principles of the present invention. As an example, but not by way of limitation, the adapter 20 could an intermediate adapter connected at its rear end to a base adapter, and the tooth point 12 could be an intermediate adapter having a front end portion on which a replaceable tooth point was installed.
Referring now to FIGS. 1 and 2, the tooth point 12 has a concavely curved rear end surface portion 28 through which a pocket 30 forwardly extends into the interior of the tooth point 12 . As can best be seen in FIG. 1, from its forward entrance into the tooth point 12 through the curved rear end surface portion 28 , the pocket 30 tapers forwardly and vertically inwardly and has a reduced cross-section stabilizing front end portion with generally horizontal opposite top and bottom side surface portions 32 and 34 .
Pocket 30 defines on the tooth point 12 a pair of opposite top and bottom side walls 36 and 38 , and a pair of opposite vertical side walls 40 and 42 which rearwardly terminate at the curved rear end surface 28 of the tooth point 12 . Rearwardly and vertically divergent rear end portions 36 a and 38 a of the top and bottom tooth point walls 36 , 38 extend rearwardly past the curved rear tooth point end surface 28 . Aligned connector openings 44 , 46 respectively extend inwardly through the vertical tooth point side walls 40 and 42 into the pocket 30 and are spaced apart along an axis 48 transverse to the axis 14 . As best illustrated in FIG. 2, a portion 42 a of the side wall 42 extends rearwardly across the connector opening 46 in a manner reducing its cross-sectional area compared to that of the other connector opening 44 .
For purposes later described herein, side wall portion 42 a (see FIG. 2) has an inner side recess which defines on the side wall portion 42 a an inner side abutment surface 50 transverse to the axis 48 and facing the pocket area 30 . Additionally, as also shown in FIG. 2, the inner side surface of the side wall opening 44 has a circumferentially extending recess 52 formed therein inwardly of the outer side surface of the side wall 40 . Recess 52 opens inwardly into the pocket 30 and has (at its top side as viewed in FIG. 2) an abutment surface 54 transverse to the axis 48 .
The adapter nose 24 is complementarily and removably received in the tooth point pocket 30 and has a connector opening 56 extending therethrough parallel to the axis 48 and aligned with the tooth point connector openings 44 , 46 . Adapter base 22 has a convexly curved front surface 58 which circumscribes the rear end of the adapter nose 24 and is complementarily and slidably engageable by the concave rear end surface portion 28 of the tooth point 12 . With the adapter nose 24 removably received in the tooth point pocket 30 as illustrated in FIGS. 1 and 2, the rear end portions 36 a , 38 a of the tooth point 12 protectively overlie top and bottom side surface portions of the adapter base 22 .
With reference now to FIGS. 1-4, the connector assembly 26 includes an elongated flat connector member 60 and a locking member 62 . Connector member 60 has opposite ends 64 and 66 , a tapered cross-section along its length which is elongated in a direction parallel to the axis 14 , opposite front and rear longitudinal side edges 68 and 70 , and corner recess areas extending laterally inwardly from the side edges 68 and 70 and defining in opposite end corner portions of the connector member 60 longitudinally inset end surfaces 72 and 74 . The outer longitudinally extending peripheral side surface 76 of the flat connector member 60 circumscribes the longitudinal axis of the connector member and is parallel thereto as opposed to being tapered with respect thereto.
A circular bore or opening 78 extends longitudinally inwardly through the inset end surface 72 of the connector member 60 and has a detent recess area formed in its interior side surface. Preferably, as best illustrated in FIG. 5, this detent recess area comprises two detent recesses 80 , 82 circumferentially separated by ninety degrees and longitudinally aligned within the opening 78 .
The lock member 62 has an elongated cylindrical body 84 a lower longitudinal portion of which (as viewed in FIG. 2) is coaxially and rotatably received within the connector member opening 78 , with an upper end portion of the body 84 projecting outwardly from the inset connector member end surface portion 72 . A transverse locking tab 86 is anchored to the exposed upper end of the lock member body 84 , and a lower end portion of the body 84 within the opening 78 has a lateral detent recess 88 extending radially inwardly through its outer side surface. As schematically depicted in cross-sectional form in FIG. 5, a detent structure 90 is received in the detent recess 88 and representatively comprises a radially outer metal detent member 92 secured to an elastomeric, radially inner detent portion 94 . The detent member 92 is resiliently biased to project outwardly from the recess 88 , but may be radially forced into recess 88 against the resilient resistance of the elastomeric portion 94 .
A noncircular driving structure 96 (for example, a hex or square head portion) projects upwardly from the locking tab 86 and may be engaged by a suitable driving tool (not shown) used to forcibly rotate the locking member 62 between (1) a locking position in which the locking tab 86 projects laterally outwardly beyond the outer peripheral side surface 76 of the connector member 60 as shown in FIGS. 1-3, and (2) an unlocking position in which the locking tab 86 does not project laterally outwardly beyond the outer peripheral side surface 76 of the connector member 60 as illustrated in FIG. 4 . The driving structure 96 could, of course, have a variety of alternate configurations, such as a noncircular recessed portion, a slotted area, or the like, if desired.
With the lock member 62 rotated to its locking position the detent member 92 snaps into the internal connector member detent recess 80 to thereby bring the elastomeric detent portion 94 to an essentially relaxed orientation and releasably retain the lock member 62 in its locking position. As the lock member 62 is subsequently being rotated from its locking position to its unlocking position, the detent member 92 is depressed into the lock member detent recess 88 and then snaps outwardly into the internal connector member detent recess 82 to thereby bring the elastomeric detent portion 94 back to an essentially relaxed state and releasably retain the lock member 62 in its unlocking position.
The same movement of the detent member 92 , of course, when the lock member 62 is subsequently rotated back to its locking position from its unlocking position. An annular resilient seal member 98 (see FIG. 2) is supported on and coaxially circumscribes the lock member body 84 , between the locking tab 86 and the lock member detent recess 88 , and slidingly engages the interior side surface of the connector member opening 78 to inhibit the entry of dirt and other abrasive material into the interior of the connector member 60 during use of the tooth adapter assembly 10 .
As can best be seen in FIG. 2, the vertical heights of the interior connector member detent recesses 80 , 82 (as viewed in FIG. 2) are substantially identical to the height of the detent member 92 . Accordingly, the interaction between the detent member 92 and these detent recesses 80 , 82 substantially prevents relative longitudinal movement between the connector member 60 and the lock member 62 when the locking member 62 is in either of its locking and unlocking positions.
With the tooth point 12 rearwardly telescoped onto the adapter nose 24 as illustrated in FIG. 2, the connector assembly 26 is operatively Installed by first rotating its lock member 62 to its unlocking position and then inserting the connector assembly 26 , connector end 66 first, downwardly (as viewed in FIG. 2) through the aligned connector openings 44 , 56 , 46 , with the front edge 68 of the connector member 60 facing forwardly, so that the connector member 60 is complementarily received in the nose connector opening 56 , and the connector member end abutment surface 74 contacts the tooth point abutment surface 50 . In this inserted orientation of the connector assembly 26 , the opposite ends 64 , 66 of the connector member 60 respectively extend into the tooth point connector openings 44 , 46 to thereby block forward removal of the installed tooth point 12 from the adapter nose 24 .
The inserted connector assembly 26 is then releasably locked in this blocking orientation by simply rotating the lock member 62 from its unlocking position to its locking position to cause the locking tab 86 to enter the tooth point recess 62 and face outwardly face its associated abutment surface 54 as may be best seen in FIG. 2 . Thus, the cooperating abutment surfaces 50 , 74 adjacent the connector member end 66 preclude the connector assembly 26 from passing outwardly through the tooth point connector opening 46 , and the cooperating abutment surfaces 54 , 72 prevent the connector assembly from passing outwardly through the tooth point connector opening 44 .
The representatively illustrated abutment surface configuration within the interior of the tooth poinvadapter assembly 10 , namely the abutment surface sets 50 , 74 and 54 , 72 , may be altered in a variety of manners without departing from the principles of the present invention. For example, but not by way of limitation, the tooth point abutment surface 50 could be relocated to within the adapter nose 24 (and the corresponding connector member abutment surface accordingly relocated to face this adapter nose abutment surface). As another example, but also not by way of limitation, the lower abutment surface set 50 , 74 (as viewed in FIG. 2) could be eliminated, and the tooth point recess 52 modified to have two facing abutment surfaces which face the opposite sides of the locking tab 86 in its locking position and serve to prevent the connector assembly 26 from longitudinally moving outwardly through either of the tooth point connector openings 44 , 46 .
Because the outer peripheral side surface 76 of the connector member 60 is parallel to the axis 48 , operating loads on the tooth point/adapter assembly 10 do not impose appreciable longitudinally directed loads on the connector member 60 which might tend to expel it from the connector openings 44 , 46 , 56 and exert substantial forces on the lock member 62 . Moreover, the connector assembly 26 may be installed without the need to pound it into the connector openings. Because of this, two or more of the assemblies 10 may be placed closer together due to the lack of required pounding room. Also, because the detent structure in the connector assembly 26 substantially prevents relative longitudinal movement between the connector member 60 and the lock member 62 during use of the tooth/adapter assembly 10 , entry of dirt and other abrasive material into the interior of the connector member 60 , and associated degradation of the interior resilient seal member 98 , is substantially reduced. Additionally, because the resilient portion of the lock member detent structure is in an essentially relaxed state in the lock member's unlocking position, undesirable “compression set” in this resilient detent portion resulting from lengthy storage periods of the connector assembly with the lock member in its unlocking position is substantially eliminated
The foregoing detailed description is to be clearly understood as being given by way of illustration and example only, the spirit and scope of the present invention being limited solely by the appended claims.
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A replaceable excavating tooth point is telescoped onto an adapter nose and releasably retained thereon by an elongated, flat connector member having an untapered side periphery. The connector member longitudinally extends through aligned point and connector openings and blocks forward removal of the point from the adapter nose. A transverse point sidewall abutment surface facing one end of the installed connector member prevents it from moving outwardly through one of the point openings, and a rotatable lock member carried by the other end of the connector member and engageable with a groove in the other point opening releasably prevents the connector member from moving outwardly through the grooved point opening. A detent structure releasably holds the lock member in locking and unlocking orientations in which the lock member is prevented from moving parallel to the length of the connector member.
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BACKGROUND OF THE INVENTION
The present invention relates to a tubular jacket for an absorber tube of a solar energy collector, especially a parabolic trough collector. The invention also relates to a parabolic trough collector for solar energy and a receiver tube for it.
A known parabolic trough collector comprises a single axis parabolic mirror and a receiver tube, which is arranged at the focus of the parabolic mirror. The mirror usually has a width of from 5 to 6 m. The receiver tube comprises a preferably radiation selective inner tube section, which is also called the absorber tube, and an outer tubular jacket made of glass for insulation. Mirror and receiver tube are directed toward the sun, so that the solar radiation always is directed normal to the aperture plane and ideally the radiation falling on the mirror is guided to the receiver tube.
Focusing errors and thus geometrically dependent optical losses occur in parabolic trough collectors due to various factors. For example, the mirror elements have a certain total shape tolerance or also waviness, which leads to focusing errors. The positioning of the mirror elements during assembly is only possible within certain tolerances. Also self-deformation, manufacturing and assembly tolerances of the steel structure, on which the parabolic trough collector is built, must be considered. Last, but not least, wind occurring in the vicinity of the parabolic trough collector leads to deformation of the entire structure and thus to focusing errors.
Currently attempts have been made to minimize optical losses by defocusing with the help of secondary concentrators mounted on the receiver tube. Already there has been an experimental use of a secondary planar reflector. An additional arrangement of a parabolic mirror with a secondary concentrator in the form of a metallic reflector has been described in WO 97/00408. A zig-zag-shaped metal sheet has been used as a secondary concentrator according to H. Price, et al, Journal of Solar Energy Engineering, Volume 124, p. 109-125 (2002).
When a highly reflective material, e.g. a polished metal sheet, is used for the secondary concentrator, it is important to put it in the tubular jacket in a vacuum, in order to protect it from dirt and aging. The secondary concentrator can be mounted either on the tubular jacket or on the absorber tube. The absorber tube is shaded by mounting the secondary concentrator above the absorber tube on the side facing away from the mirror. When the secondary concentrator is wider than the absorber tube, also a part of the mirror is shaded. If the secondary concentrator is attached to the tubular jacket, a part of the radiation, which falls on the side of the secondary concentrator facing away from the mirror, is lost, since the tubular jacket and the absorber tube are thermally decoupled. It is possible to use a portion of this radiation when the secondary concentrator is attached to the absorber tube and is made absorbing on the side facing away from the mirror. Because of that feature more radiation can be utilized. At the same time however the increase in the absorber surface area increases the thermal losses.
The increase of the interceptor factor (the fraction of the radiation, which falls on the absorber tube), which is achieved by the secondary concentrator, is necessarily accompanied with radiation losses on account of the above-mentioned disadvantages. No significant improvement of the interceptor factor may therefore be achieved in total.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a tubular jacket for a parabolic trough collector, which helps to provide the highest possible interceptor factor, thus increasing the amount of solar energy that is collected.
It is another object of the present invention to provide a receiver tube for a parabolic trough collector, which helps to collect more solar radiation than conventional receiver tubes of the prior art and has the highest possible interceptor factor.
It is a further object of the present invention to provide a parabolic trough collector for solar energy, which has a receiver tube with the highest possible interceptor factor.
According to the present invention the tubular jacket or jacket tube for a parabolic trough collector has structural elements, which focus sunlight on an absorber tube arranged in the tubular jacket or jacket tube, by deflection and/or detraction of the sunlight.
According to the present invention a receiver tube for a parabolic trough collector comprises a tubular jacket and an absorber tube arranged in the tubular jacket. The tubular jacket has structural elements, which focus sunlight on the absorber tube arranged in the tubular jacket, by deflecting and/or defracting sunlight.
According to the present invention the parabolic trough collector for solar energy comprises a parabolic mirror having a focal point and a receiver tube arranged at the focal point of the parabolic mirror. The receiver tube comprises an absorber tube and a tubular jacket around the absorber tube, wherein the tubular jacket comprises structural elements, which focus sunlight on the absorber tube arranged in it, by deflecting and/or detracting sunlight.
Because of the focusing structural elements in the tubular jacket, radiation, which would enter from a certain angular range through a smooth or unstructured tubular jacket and leave again without impinging on the absorber tube, now is directly guided to the absorber tube surface. This especially concerns rays, which come to the tubular jacket from the outside region of the parabolic mirror, as well as rays, which impinge directly on the tubular jacket from the sun. The structural elements of the tubular jacket are preferably formed to particular focus the rays that reach the tubular jacket from the outer region of the parabolic mirror on the absorber tube. The optical structuring of the tubular jacket causes an optical widening of the absorber tube similar to a magnifying effect for the above-mentioned angular range. Depending on the size and spatial distribution of the mirror errors an increase of the optical efficiency of about 1 to 3% can be achieved.
With larger mirror and assembly errors the increase of the optical efficiency can turn out to be still higher. The use of a tubular jacket according to the invention can also accommodate higher tolerances in mirror manufacture and assembly, which leads to clearly reduced costs.
An additional advantage of the tubular jacket according to the invention is that the thermal load is distributed somewhat uniformly over the absorber tube. Parabolic trough collectors have the undesirable property that the side of the absorber tube facing the mirror is many times more strongly irradiated than the side facing away from the mirror. Because of this property usually temperature gradients arise over the tube circumference, which lead again to material stress and deformation. Because of the focusing, especially of the rays falling directly on the tubular jacket and rays that are axially remote from the absorber tube, the side of the absorber tube facing away from the mirror is somewhat more strongly irradiated when the tubular jacket according to the invention is used.
The focusing structural elements of the tubular jacket advantageously can be a plurality of lenses, a plurality of polyhedrons, and especially preferably a plurality of prisms. These types of optical elements have the property of focusing on the interior of the tubular jacket and thus on the absorber tube.
The focusing structural elements can be provided by a suitably structured foil, which is mounted on the inner or outer side of the tubular jacket. The mounting on the outside is changed more easily from a manufacturing engineering standpoint. In order to protect the foil from weathering effects and dirt the foil can be attached to the inner side of the tubular jacket prior to assembly. When the foil is to be attached, the fact that the foil is optically coupled to the tubular jacket should be considered. It can, for example, be glued or laminated.
In a preferred embodiment the tubular jacket is a drawn glass tube. The focusing structural elements are constant or do not change in the longitudinal direction along the tubular jacket in the drawn glass tube. Lens-shaped structural elements are obtained e.g. by a wavy structuring of the inner and/or outer wall of the glass tube. Prismatic or prism-shaped structural elements were obtained by a substantially zig-zag structuring of the inner and/or outer wall of the glass tube. In practice with the prismatic structural elements a rounding off of the prisms can be avoided only to the extent of the current engineering capabilities.
Preferably the tubular jacket has an antireflective coating on at least one of the inner side and outer side. Because of that it is guaranteed that a maximum portion of the radiation impinging on the tubular jacket is guided to the absorber tube and not reflected to the outside.
It has proven advantageous to provide structured regions only over at least one segment. For example, the structuring is interrupted at least partially in the region in which the radiation falls directly on the absorber tube without deflection by the focusing structural elements of the tubular jacket on the side facing the sun. An arrangement in which the structural elements are provided in the tubular jacket symmetrically in two strips on respective opposite sides of the normal axis of the parabolic mirror in angular regions of 20° to 105°, especially of 35° to 65°, is particularly preferred.
In a preferred embodiment of the parabolic trough collector the receiver tube is displaced somewhat relative to the focal point in the direction of the parabolic mirror by a distance equal to about half the spacing between the tubular jacket and the absorber tube. Because of that displacement losses from radiation, which misses the absorber tube, in that it passes under the receiver tube, namely between the receiver tube and the mirror, are reduced. The result is that thermal load is distributed more equally over the absorber tube, so that a smaller temperature gradient over the tube circumference, and thus smaller deformation and material stresses, result.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
The objects, features and advantages of the invention will now be illustrated in more detail with the aid of the following description of the preferred embodiments, with reference to the accompanying figures in which:
FIG. 1 is a schematic cross-sectional view of a parabolic trough collector;
FIG. 2 is a diagrammatic cross-sectional view of the path of a radiation beam traveling in a receiver tube of a parabolic trough collector;
FIG. 3 is a diagrammatic cross-sectional view of the path of radiation in a parabolic trough collector showing the origin of focusing errors;
FIG. 4 is a cross-sectional view of a receiver tube with a segmented tubular jacket;
FIGS. 5 a , 5 b , 5 c and 5 d are respective cross-sectional views of several embodiments of tubular jackets provided with focussing structural elements according to the invention;
FIG. 6 a is a schematic cross-sectional view through a receiver tube with a conventional tubular jacket, showing the path of peripheral rays;
FIG. 6 b is a schematic cross-sectional view through a receiver tube with a tubular jacket structured according to the invention, showing the path of radiation remote from the axis;
FIG. 7 a is a schematic cross-sectional view through a receiver tube with a conventional tubular jacket, showing the path of radiation coming directly from the sun;
FIG. 7 b is a schematic cross-sectional view through a receiver tube with a tubular jacket structured according to the invention, showing the path of radiation coming directly from the sun;
FIG. 8 a is a graphical illustration of the variation of the dependence of local interceptor factor on distance from the optic axis in the case of the tubular jacket according to the invention;
FIG. 8 b is a graphical illustration of the dependence of interceptor factor on angle of incidence in the case of the tubular jacket according to the invention; and
FIG. 9 is a cross-sectional view through a parabolic trough collector having a receiver tube with a tubular jacket according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 a parabolic mirror 1 and a receiver tube 2 are illustrated. The receiver tube 2 is arranged at the focus of the parabolic mirror 1 in the arrangement shown in FIG. 1 . Incident radiation on the side of the receiver tube facing the sun always impinges in the normal direction, since the mirror 1 and the receiver tube 2 are pointed exactly toward the position of the sun. Radiation impinges at an angle between 160° and 180° on the side of the receiver tube 2 facing the mirror. The arrows in FIG. 1 show the incidence angles.
In FIG. 2 a conventional receiver tube 2 is shown, which comprises an absorber tube 4 and a tubular jacket 3 . The radiation beam 5 , 5 ′ is a beam, which passes comparatively far from the optic axis of the collector, while the radiation beam 6 , 6 ′ is a beam, which passes comparatively close to the axis. Both beams pass through the tubular jacket 3 without striking the absorber tube 4 .
In FIG. 3 the focussing error due to mirror deformation is illustrated by example. The losses arise principally in the outer region of the parabolic mirror 1 , since the error has a greater effect because of the greater distance to the receiver tube 2 . Because of the greater distance between the mirror 1 and the receiver tube 2 an incident beam spreads to a greater beam cross-section in the case of a comparatively far beam 8 (as measured with respect to the optic axis O) than in the case of a comparatively near beam 7 . As usual the deformation of the mirror 1 is greater at the edges of the mirror than at its center because of the undesirable load distribution. The mirror error additionally increases with increasing distance from the optical axis O because of that. The focusing error has diverse consequences. Radiation beam 8 , which falls on the tubular jacket 3 from the edge region of the mirror, passes through it to a part on the upper side facing away from the mirror. Radiation beam 7 , which is directed at the mirror center, falls on the receiver tube 2 almost without any losses. Beams, which pass through the tubular jacket 3 before they reach the mirror 1 , fall in part on the absorber tube 4 . A further part leaves the tubular jacket 3 , without falling on the absorber tube 4 and is guided toward the mirror 1 . However because of the tubular jacket 3 the beams are partially deflected strongly, so that they miss the absorber tube 4 after reflection at the mirror 1 .
In FIG. 4 a receiver tube 2 is shown, which comprises an absorber tube 4 and a tubular jacket 3 structured in certain segments. In the embodiment shown in FIG. 4 the structuring in the region a of the tubular jacket 3 , in which the radiation comes directly from the sun to the absorber tube 4 without additional deflection, is omitted. That is region a is not structured. Moreover the structuring is omitted in the region of the tubular jacket 3 facing the mirror. Since the incoming beam angle space on the side facing the mirror is almost completely filled, no significant increase of the interceptor factor can be achieved by structuring this region. Especially in the lower tubular jacket region, in which the radiation falls on the absorber tube 2 from an angular range near 180°, a small local reduction in the interceptor factor might even result.
It has been shown that at least one segment or region designated by c should be structured, which means the structuring or structure elements should be provided in an angular region of 35° to 65° to the normal axis N of the parabolic mirror surface. An additional increase of the interceptor factor can be achieved when the segments designated by b and d are provided with structural elements or structured. This corresponds to an angular range of 20° to 105° to the normal axis N of the parabolic mirror surface. Assuming a mirror angular error of e.g. 4 to 5 mrad, an increase of interceptor factor of up to 3% may be achieved.
In FIG. 5 a to 5 d specific embodiments of tubular jacket 3 according to the invention are illustrated in cross section to show the structured elements 9 a to 9 d for focussing more radiation on absorber tube 4 . Three tubular jackets 3 of FIGS. 5 a , 5 b and 5 c have structural elements or structuring 9 a , 9 b , 9 c only in a certain angular region. A lens-shaped structuring or lens-shaped structural elements 9 a are shown in FIG. 5 a . A prism-shaped structuring or prism-shaped structural elements 9 b are shown in FIG. 5 b . Zig-zag shaped structural elements 9 c are shown in FIG. 5 c . The structural elements shown in FIG. 5 d , which are prism-shape, are provided on a foil 19 that is placed on the outside of the tubular jacket 3 . In other embodiments the foil may be placed on the inside of the tubular jacket. These structural elements or structuring in these embodiments provide an optimized interceptor factor. The boundary surfaces are selected so that as great as possible focussing on the absorber tube is attained for a given incidence angle and mirror error.
In FIG. 6 a the path of rays is shown in a receiver tube 2 comprising a conventional glass tubular jacket 3 of a given thickness and an absorber tube 4 . The ray path shown in FIG. 6 a is for a beam that is comparatively far from the optic axis. Individual rays, which do not reach the absorber tube 4 , occur especially in the part 3 ′ of the tubular jacket 3 facing away from the mirror 1 . Furthermore a gentle defocusing effect of the part 3 ′ of the tubular jacket 3 is observed. It is caused by the given thickness of the tubular jacket 3 and by the difference between the index of refraction of glass and air or glass and vacuum. In the embodiment of FIG. 6 b the tubular jacket 3 includes zig-zag structural elements 2 ′ according to the invention, especially in the angular region 90° to 20° to the normal axis N. The zig-zag surface shape or profile, like an arrangement of prisms, acts on the incident radiation that is comparatively far from the axis so that a large part of the otherwise defocused incident radiation is guided to the absorber tube 4 .
FIGS. 7 a and 7 b show the same arrangement as in FIGS. 6 a and 6 b , but for radiation which falls directly from the sun on the receiver tube 2 comprising the absorber tube 4 and the tubular jacket 3 . The ratio of the radiation, which falls on the absorber tube 4 and which is deflected away from it, corresponds to the ratio of the cross-sectional areas in a longitudinal section through the absorber tube 4 and through the tubular jacket 3 ( FIG. 6 a ). Furthermore the defocusing effect of the part 3 ′ of the tubular jacket 3 on the normal radiation is especially clear. Of course even using the tubular jacket 3 according to the invention with the structured region not all rays are guided to the absorber tube 4 . However the portion of the radiation incident on the tubular jacket 3 that reaches the absorber tube 4 can be significantly increased.
This effect is also clearly understandable with the help of the graphical illustrations in FIGS. 8 a and 8 b . FIG. 8 a shows the dependence of the local interceptor factor in percent on the distance to the optic axis in millimeters. The solid curve corresponds to the curve obtained with a conventional or prior art unstructured tubular jacket. The dashed curve corresponds to the curve obtained using a tubular jacket with the focussing structural elements according to the invention. A definite increase of the interceptor factor for radiation coming directly from the sun (spacing to the optic axis of about 0 mm) and for radiation that is spaced in a region comparatively far, about 2000 mm, from the axis is observed. Also the interceptor factor is increased by the focussing structural elements in the tubular jacket between about 1% (incident angle between 0° and 10°) and about 3% (incidence angle between 50° and 60°).
In FIG. 9 a preferred arrangement of the receiver tube 2 comprising the absorber tube 4 and the tubular jacket 3 in relation to the parabolic mirror 1 is sketched. Conventionally the receiver tube 2 is arranged at the focal point F. According to the invention, in order to reduce the number of rays that miss the absorber tube by passing under the receiver tube 2 , the receiver tube 2 (i.e. its center or the center of the absorber tube) is displaced from the focal point F in the direction of the parabolic mirror 1 by a distance equal to about half of the spacing d between the tubular jacket 3 and the absorber tube 2 .
In certain embodiments the tubular jacket 3 may be provided with an antireflective coating on an inside surface 17 as shown in FIG. 7 b and/or on an outside surface 11 as shown in FIG. 6 b.
The disclosure in German Patent Application 103 05 428.6-15 of Feb. 3, 2003 is incorporated here by reference. This German Patent Application describes the invention described hereinabove and claimed in the claims appended hereinbelow and provides the basis for a claim of priority for the instant invention under 35 U.S.C. 119.
While the invention has been illustrated and described as embodied in a tubular jacket for an absorber tube of a parabolic trough collector, a receiver tube of the parabolic trough collector and a parabolic trough collector, it is not intended to be limited to the details shown, since various modifications and changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.
What is claimed is new and is set forth in the following appended claims.
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The parabolic trough collector includes a single-axis parabolic mirror ( 1 ) and a receiver tube ( 2 ) arranged at the focal point (F) of the parabolic mirror ( 1 ). The receiver tube ( 2 ) includes an absorber tube ( 4 ) and an outer tubular glass jacket ( 3 ) around it. To compensate for focusing errors in the parabolic collector and thus to reduce associated geometric optical losses, the tubular jacket ( 3 ) is provided with structural elements ( 9 a , 9 b , 9 c , 9 d ), which focus sunlight reflected from the mirror as well as sunlight that falls directly on the receiver tube from the sun on the absorber tube. The receiver tube is preferably arranged relative to the parabolic mirror, so that its center is displaced from the focal point (F) by a distance equal to half the spacing between the tubular jacket ( 3 ) and the absorber tube ( 4 ).
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CROSS-REFERENCE TO RELATED APPLICATION
This application is related to the copending application Ser. No. 707,616, filed Mar. 4, 1985, entitled "Current Limiting Solenoid Operated Circuit Breaker", of Y. K. Chien, W. V. Bratkowski, and J. A. Wafer; and Ser. No. 707,632, filed Mar. 4, 1985, entitled "Remotely Controlled Solenoid Operated Circuit Breaker" of W. V. Bratkowski and J. A. Wafer, both assigned to the present assignee.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention generally relates to circuit breakers useful for remote power control and energy management for residential, commercial, and industrial applications.
2. Description of the Prior Art
From 1970 to 1980 energy was a major concern in the United States and the cost of electric power rapidly increased and provided significant economic incentive to conserve energy. It was during this time that an energy crisis occurred. Although the energy crisis has now passed, energy will continue to be a critical factor in the economy. Electric utilities are becoming increasingly concerned with energy management and conservation. A forecast of supply, demand, and cost of electrical energy will increase during the next fifteen years by approximately a factor of two. If the current lifestyle is to be preserved, energy must be more efficiently used in the future for which reason energy management systems will play a vital role in this future.
Although breaker/switch devices for remote control are in use for commercial and industrial applications, the devices have involved solenoid operated mechanisms which are disposed along the bottom edge of a circuit breaker housing opposite the edge from which the manual handle extends for actuation of a contact carrying arm. The armatures of such solenoids have extended parallel to the longitudinal axis of the longer dimension of the circuit breaker. As a result, such circuit breakers have not been adaptive to insulation in standard circuit board panels used for existing residential application. In other words, a smaller circuit breaker having a remotely controlled solenoid for residential use has been necessary.
SUMMARY OF THE INVENTION
In accordance with this invention a circuit breaker for use in remote control is provided which comprises an insulating housing having electrical terminals thereon; separable contact means including a stationary contact and a movable contact disposed in the housing to form a circuit breaker path between the terminals; manual actuating means within the housing for operating the circuit breaker and including an operating lever and a release lever for opening and closing the movable contact member; the actuating means also including an assist lever operable on the movable contact and cooperable with the operating lever to close the contacts; first electromagnetic means having an armature for actuating the movable contact and energized by an electric pulse for opening or closing the circuit from a remote circuit; coupling means between the first electromagnetic means and the movable closing of the contacts by the first electromagnetic means when the manual actuating means is in a open-contact position; the movable contact comprising an overcenter toggle structure; the operating lever and the assist lever cooperating to move the toggle structure overcenter to the closed-contact position; the operating lever and the assist lever being disposed on opposite sides of the toggle structure; second electromagnetic means for actuating the movable contact to an open circuit position in response to the occurrence of a short circuit condition; the coupling means including a link and a connecting lever; the link extending between the movable contact and the connecting lever; the connecting lever extending between the armature and the link; one of the link and connecting lever having a pin-receiving slot extending substantially in the direction of movement of the link; and the other of the link and connecting lever having a pin extending into the slot, whereby operation of either of the manual operating means and the electromagnetic means is independent of the other.
The advantage of the device of this invention is that it provides for remote control and energy management within a circuit breaker housing which is adapted for installation in a conventional circuit breaker panel such as of the residential size, and which is compatible with both AC and DC control power from direct or solid state logic sources. The control signal can be a steady state or a pulsed operation.
Moreover, if control voltage stays on and a short circuit occurs, the circuit is opened either by a bimetal trip or a short circuit trip coil. These features are due to the design of the mechanism or electromagnetic trip. The contact will open and latch out, even though the coil is still energized. This is desirable because, if a short circuit occurs, the electromagnetic actuator or bimetal cannot act fast enough to clear the fault as quickly as necessary.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical, sectional view through a circuit breaker with the contacts in the closed condition, taken on the line I--I of FIG. 3;
FIG. 2 is another embodiment of the circuit breaker of FIG. 1; and
FIG. 3 is a plan view of the circuit breakers of FIGS. 1 and 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1, a molded breaker is generally indicated at 11 and it comprises a housing 13, and a circuit breaker structure 15 which includes a stationary contact 17 and movable contact 19, means for actuating the movable contact including a handle 21, a current-limiting electromagnetic mechanism or short circuit trip device 23, an electromagnetic means or solenoid 25, and a bimetal strip 41. The circuit breaker 11 also comprises an arc-quenching device 27, a line terminal 29, and a load terminal 30.
The housing 13 comprises a body 31 and a detachable cover 33 (FIG. 3), both of which are comprised of an electrically-insulating material, such as an epoxy resin or thermal plastic material.
The circuit breaker structure 15 is mounted within the chamber of the housing 13 and comprises an unlatching mechanism 39. In addition, the circuit breaker 11 comprises four mechanisms for opening the contacts 17, 19 which mechanisms include the manual handle 21, the current limiting electromagnetic device or short circuit device 23, the bimetal strip 41, and the electromagnetic structure 25. The unlatching mechanism 39 includes an operating or kicking lever 43 and a releasing lever 45, both of which are pivotally mounted on a pivot pin 47. The releasing lever 45 fits over a recess of the operating lever 43 where it is retained in place by a bias spring 49. A wire bail 51 extends from the handle 21 to the upper end of the releasing lever 45. The unlatching mechanism 39 functions in a manner set forth more particularly in U.S. Pat. No. 4,001,743 which is incorporated herein by reference. Suffice it to say, when the handle 21 is rotated from the ON to the OFF position, the kicking and releasing levers 43, 45 rotate against the movable contact 19 to move it away from the stationary contact 17. For that purpose, the lower end of the movable contact is pivotally mounted in a hole 53 in an arc guide rail 54.
When a current overload occurs, such as six or more times the rated current, the short circuit device 23, which includes a coil 55 and an armature 57, is actuated to rotate the kicking lever 43 counterclockwise to move the movable contact 19 away from the stationary contact 17 and thereby open the circuit.
When there is a slow increase in the rated current, the bimetal strip 41 heats up and rotates clockwise about its mounting 44 at the lower end of the strip where it is mounted on a terminal conductor 56. As the bimetal strip 41 rotates clockwise, it moves an armature 57 to the right, whereby a hook 59 at the left end of the link 58 rotates the lower end of the kicking lever 43 against the upper end of the movable lever 19, thereby opening the circuit. Whereas, the bimetal strip 41 operates in response to a slow increase in the rated current and thereby heats up over a given time period, the short circuit device 23 responds more quickly to a large overload.
The electromagnetic coil 25 functions with a bistable toggle mechanism 61 to open and close the contacts 17, 19. The electromagnetic structure 25 includes a coil 63, an armature 65, and a coil spring 67. The spring is disposed between the coil and a flanged end 69. The lower end of the armature 65 is pivotally connected at 71 to a lever or bellcrank 73 which is pivotally supported at 75. The lever 73 includes a propeller 77 for actuating the bistable toggle mechanism 61 between positions corresponding to open and closed conditions of the contacts 17, 19. Inasmuch as the construction and operation of the bistable toggle device is set forth in copending application Ser. No. 707,632, filed Mar. 4, 1985 entitled "Remotely Controlled Solenoid Operating Circuit Breaker", of J. A. Wafer and W. V. Bratkowski, only a limited description is set forth herein. The bistable mechanism includes lever 79, mounted on a pin 81, a flipper 83, and a toggle spring 85. The bistable toggle mechanism 61 is rotated about the pivot pin 81 to move the movable contact between open and closed positions of the stationary contact 17. For that purpose a link 87 is pivotally mounted between the movable contact 19 on a pin 89. A pin 91 on the upper side of the lever 79 extends through a slot 93 on the right end portion of the link 87.
When the contacts 17, 19 are closed, a circuit through the circuit breaker 11 extends from the line terminal 29, the coil 55, the stationary contact 17, movable contact 19, a shunt 95, the bimetal strip 41, the connector 44, the terminal conductor 56, to the load terminal 30.
The electromagnetic structure 25 is actuated by a pulse of current for moving the movable contact between open and closed positions of the contacts 19. For that purpose, to open the contacts a pulse of current is applied to the coil 63, whereby the flanged end 69 of the armature is pulled toward the upper end of the core 66 to thereby rotate the lever 73 clockwise about the pivot 75. The propeller 77 moves against the flipper 83 to rotate the lever 79 clockwise about the pivot pin 81 from the position shown (FIG. 1), thereby pulling the link 87 to the right to separate the contacts. When that action occurs, none of the other operating parts including the handle 21, the short circuit device 23, or the unlatching mechanism 39 operates. After the current pulse occurs, the spring 67 raises the armature 65 to the upper position (FIG. 1), whereby the pin 91 travels through the slot 93 to the opposite end thereof, without moving the link.
Subsequently, when a pulse of current is applied to the electromagnetic structure 25, the propeller 77, acting against the flipper 83, rotates the lever 73 in the counterclockwise direction, thereby moving the movable contact 19 to the closed position via the link 87. Once again, the spring 67 raises the armature to the position shown and the lever 79 returns to the position shown with the pin 91 in the right end portion of the slot 93.
It is noted that the slot 93 extends in a direction of movement of the link 87. Accordingly, when one of the other contact moving structures, such as the handle 21, the short circuit device 23, or the bimetal strip 41, acts to move the movable contact 19 to the open contact position, the position of the bistable toggle mechanism 61 is undisturbed, because the slot 93 travels over the pin 91. In other words, the slot 93 provides the circuit breaker 11 with a trip-free function, that is, if the handle 21 is locked in the ON position, the circuit breaker can perform its normal interruption functions including remote control, bimetal trip, and overload or short circuit tripping.
In FIG. 2 another embodiment of a circuit breaker 101 is shown in which an electromagnetic device 103 is provided which differs from that of the electromagnetic structure 25. In both embodiments of the circuit breakers 11 and 101, similar numerals refer to similar parts. The electromagnetic device 103 comprises a coil 105, a core 107, an armature 109, and a coil spring 111. The lower end of the armature 109 is connected by a pin 71 to a lever or bellcrank 113 which is pivotally mounted at 115. The upper end of the bellcrank 113 includes a pin 91 which is disposed in the slot 93 of the link 87. In the position of the electromagnetic device 103, the coil 105 is energized so that the upper end of the armature is disposed against the central core and the spring 111 is compressed. In this position, the pin 91 is disposed in the right end of the slot 93 and the contacts 17, 19 are closed. So long as the core 105 is energized, the movable contact is free to move between open and closed positions in response to actuation by either the handle 21, the coil 55, or the bimetal strip 41. The foregoing is true due to the location of the pin 91 within the slot 93.
When, however, the coil 105 is de-energized, the coil spring 111 moves the armature 109 downwardly to rotate the bellcrank 113 clockwise about the pivot 115 and to cause the pin 91 to move the link 87 to the right and thereby open the contacts 17, 19. So long as the coil 105 is de-energized, it is impossible for the contact 19 to be moved to the closed position with the contact 17, such as by the handle 21, the coil 55, or the bimetal strip 41.
Accordingly, when the coil 105 is energized, the contacts are closed. Conversely, when the coil 105 is de-energized, the contacts are open. On the other hand, due to the provision of the bistable toggle mechanism 61 (FIG. 1), the electromagnetic structure 25 is pulse-operated, that is, a pulse of current to the coil 63 moves the bistable toggle mechanism 61 to a position corresponding to the open contact position. However, a subsequent pulse of current through the coil 63 actuates the bistable toggle mechanism 61 to the alternate position of the contacts 17, 19.
In conclusion, the circuit breakers of this invention provide a current limiting solenoid operated means for an energy management system by an electric pulse or a continuing current operation. Moreover, the device of this invention performs the function of a circuit breaker as well as a remotely controlled switch and is compatible with both AC and DC control power from direct or solid-state logic sources. The control signal can be either steady state or a pulsed operation.
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A circuit breaker for use in remote load energy management systems and characterized by an insulating housing including opposite side walls, end walls and edge walls with a circuit breaker structure contained therein; a manual operator including a handle extending through an edge wall for actuating the structure between open and closed circuit conditions; an electromagnetic within the housing and including an armature for opening the circuit which armature is movable in an axis substantially perpendicular to the edge walls.
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BACKGROUND OF THE INVENTION
The invention relates to a moulding tool for a machine for processing glass or other plastic material, the tool comprising at least one mould middle section divided into middle section parts, and an operating device having members each carrying with clearance a respective one of the mould middle section parts for opening and closing movements transversely of the longitudinal axis of the respective mould and transversely guiding the parts in two spaced guide planes by means of guide elements.
A known moulding tool of this kind (West German Offenlegungsschrift 2,355,030) comprises a multiple mould with which appertaining mould middle section halves are respectively on their outside provided with a downwardly extending flange at their upper end and, approximately in half their longitudinal extension, with a headed screw. The flange, with radial clearance, is suspended on a suspension console of a tong half forming the operating device. A head of the headed screw, with radial clearance, engages downwardly in a groove of the tong half. Thus two radial guide planes are defined. The mould middle section halves are not secured in the axial direction and so under unfavorable operating conditions can be lifted upwardly and fall out of the operating device. Two pressure members of the appertaining tong half engage each mould middle section half, whereby two axial holding closed force zones are defined. The pressure members are arranged in spaced relationship and one above the other respectively below one of said two guide planes.
The object of this known moulding tool is to exert to the mould middle sections of all the individual moulds of said multiple mould a holding closed force of like magnitude. To this end all the pressure members of each tong half are constantly connected to each other via a closed hydraulic channel system, so that, when the moulding tool is firmly closed, each pressure member exerts a holding closed force of like magnitude to the appertaining mould middle section. In this condition the mould middle section halves shall be held by the tong halves freely movably in the radial direction and "floatingly." A disadvantage is that the line of action of the holding closed force resulting from both the pressure members of each mould middle section half does not coincide with the line of action of the resultant opening force acting on the respective mould middle section half. That is why it is known to happen that the mould middle section will open either at its top or at its bottom and split apart obliquely under the internal pressure existing during the processing. This results in the formation of more or less coarse seams on the parisons and on the finished hollow glass products. These seams are unsightly and degrade the strength and quality of the product. They can also result in rejected articles, in particular at the finishing mould stage. Furthermore the tendency to split open involves unequal wear of the mould middle sections. On account of the mould cracking or splitting it is not possible to produce all types of hollow glass articles with the known moulding tools.
Another disadvantage is that the radially "floating" suspension of the mould middle sections on the tongs precludes centering of the mould middle sections with respect to the remainder of the moulding tool. This may lead to uneven production and increased wear of the moulding tool.
With the known moulding tool the holding closed force is applied by the tongs. If the tong halves are not absolutely parallel to the longitudinal axes of the individual moulds, oblique and edgewise contacting of the pressure members and the mould middle sections and, with the piston-like pressure members, jamming between the pressure members and their cylinders may occur. This again enhances the wear and creates the danger of leakages in the hydraulic system resulting in the loss of the critical preadjustment thereof. Said preadjustment and consequently desired functioning of the known moulding tool are also endangered by the continuous operational temperature changes of the moulding tool.
When the machine is in operation, due to the occurrence of irregular thermal loads, e.g. during the starting up of the machine, correspondingly irregular thermal expansion takes place of the mould middle section and the operating device, so that correspondingly wide tolerances must be available in the means for suspension and guidance between the mould middle section and the operating device. At the times when the mould middle sections are not securely closed, the effect of these tolerances is to allow varying oscillations of the mould middle sections about a transverse axis with respect to the operating device, and wear between these parts caused by the resulting impacts. This again increases the machine noise. These disadvantages further accumulate as the production speed increases.
SUMMARY OF THE INVENTION
One object of the present invention is to assure that the holding closed force is transmitted in a definite manner to the mould middle section, so as to avoid an undesirable gaping of the parts of the mould middle section and of other parts of the moulding tool during a moulding process. A further object of the invention is to reduce the wear on the moulding tool and the means for its suspension and guidance.
These objects are obtained by the present invention in that the total force for holding closed the parts of the mould middle section is transmitted by the operating device to these parts in such a manner that the line of action of the resultant holding closed force component for each part of the mould middle section coincides substantially with the line of action of the resultant opening force component of the respective part of the mould middle section, while each resultant holding closed force component substantially coincides with the respective mould opening force component.
The resultant mould opening force component originates firstly from the forces acting internally of the moulding tool, and secondly from the forces which arise due to any mechanical clamping between the mould middle section and one or more of the other parts of the moulding tool, and which likewise have the tendency to open the mould center section. The force effects acting internally of the moulding tool include the internal pressure resulting from the pressing or preliminary blowing in the parison forming phase resulting from the final blowing in the finishing mould phase.
In each part of the mould middle section the resultant of these internal force effects passes through the surface centroid of the projected surface of the particular part of the mould middle section which is in contact with the plastic material being moulded. Therefore the invention takes into account, in the concept of the resultant opening force, all those forces acting in the direction of opening when the moulding tool is in the closed condition, and for solving the problem dealt with by the invention these forces are overcome by the selection of the point of application of the holding closed force. This applies independently of the variations in length of the moulding tool caused by varying thermal stresses. Preferably the mould middle section comprises two parts, which are movable at right angles to the longitudinal axis of the moulding tool by means of the operating device, for example tongs. The invention is applicable not only to an individual mould but likewise to a moulding tool having a plurality of such moulds, for example a double mould.
According to one practical form of the invention the total force for holding closed the parts of the mould middle section is transmitted to said parts by the operating device in a common holding closed force plane directed at right angles to the longitudinal axis of the moulding middle section or in an axial holding closed force zone. By these means the outlay expended for transmitting the holding closed force zone is in any case only a small part of the total axial length of the mould middle section and is finally determined according to the necessary magnitude of the contact surface between the operating device and the mould middle section, in order that the permissible surface pressures may not be exceeded when applying the holding closed force.
According to a further practical form of the invention a guide plane is situated at either side of the holding closed force plane or the holding closed force zone. In such a case the spacing distance between the two guiding planes may be comparatively large, and any possible pivoting of the parts of the mould middle section about a transverse axis can be kept comparatively small.
According to another practical form of the invention the total force for holding closed the parts of the mould middle section is transmitted to said parts by the operating device in two holding closed force planes or axial holding closed force zones axially spaced from each other and each directed at right angles to the longitudinal axis of the moulding tool. In this case, as compared with the application of the force in only one holding closed force plane or holding closed force zone, the technical outlay for the transmission of the holding closed force planes or holding closed force zones can be available for other purposes, for example special arrangements for conveying cooling air.
According to a further practical form of the invention, the operating device for each part of the mould middle section comprises a pivoting frame, which is firstly connected through a joint to a support for the operating device, and secondly is provided, in each of the two holding closed force planes or holding closed force zones, with at least one holding closed force transmission element cooperating with the respective middle section part of the mould. Appropriately, according to the invention, the joint is designed as a ball joint. The joint makes possible automatic pivoting adjustment of the parts of the mould with respect to each other, when the mould middle section is closed.
According to a further practical form of the invention there is arranged between each support and the appertaining pivoting frame at least one biased spring element for adjusting a definite rest position of the pivoting frame. In particular this rest position can be so selected that the longitudinal axes of the individual parts of the mould middle section extend parallel to each other. For this purpose the spring force of at least one of the spring elements can be adjustable.
According to a further practical form of the invention each part of the mould middle section engages over the appertaining part of the operating device by means of guide elements, in which case at least one guide element is directed oppositely to the other guide element or elements. Notwithstanding an axial clearance between the operating device and the guide elements made necessary on account of the relative changes in length due to thermal influences, the arrangement here discussed ensures that the parts of the mould middle section can no longer fall out of the operating device.
According to a further practical form of the invention each part of the mould middle section is insertable with circumferential clearance into the appertaining part of the operating device by pivoting about its longitudinal axis, and is again removable therefrom, while when the mould part is in the inserted condition a releasable locking device prevents further pivoting thereof. The locking device may include a spring loaded bolt having circumferential clearance with respect to the appertaining part of the mould middle section.
According to a further practical form of the invention at least one spring element of each part of the operating device constantly bears with bias against the appertaining part of the mould middle section and, when the mould middle section is open, all radial clearance between the part of the operating member and the appertaining guiding elements in the outward or the inner direction is brought to zero. This arrangement has the substantial advantage that even when the mould middle section is open the parts thereof are no longer able to pivot about a transverse axis. On the contrary these parts are then situated in a definite position, preferably with their longitudinal axes exactly parallel to each other. This arrangement avoids the continual and constantly changing impact between the suspended parts, which was present in the known arrangements, as well as avoiding the accompanying wear and noise. Moreover, upon closing the mould middle section, the parts thereof move towards each other in an optimum relative position and interengage in the region of the conventional matching cross-sections in a manner such that the amount of wear on the parts is reduced to a minimum. This applies in a like manner to other components of the moulding tool, for example the neck mould, which in the closed position engages with the mould middle section. The spring elements can be so adjusted that above-mentioned advantages apply also in the case where the parts of the mould middle section are influenced not only by closing and opening accelerations but also by additional accelerations resulting from movements superimposed upon the entire moulding tool. An example of such additional acceleration is the centripetal acceleration arising from the use of a rotating table. According to a feature of the invention the spring element is arranged in the locking force plane or in the locking force zone. In such a case the best arrangement is one in which only one spring element is used for each part of the mould middle section. Moreover in such a case the applied forces necessary for holding closed the parts of the mould middle section are transmitted in a particularly favorable manner to said parts in the holding closed force plane or the holding closed force zone.
According to a further practical form of the invention each component part of the operating device comprises one or more holding closed force transmission elements. The holding closed force transmission elements may according to the invention be of block shape and may be designed complementary to an oppositely positioned contact surface of the respective part of the mould middle section. The holding closed force transmission element or elements of at least one part of the mould middle section may, according to the invention, be designed of spherical or blade form in respect of that part thereof which comes into contact with the appropriate part of the mould middle section. In each case it is possible, when closing the mould middle section, to position the respective part thereof easily and accurately to suit the end position of the oppositely positioned part of the mould middle section and thereby to effect the desired uniform transmission of the holding closed force into the mould middle section.
According to a further practical form of the invention, for the purpose of closing the mould tool a mould middle section engages with a part of a neck mould for the three-dimensional relative positioning of the neck mould and the mould middle section by the use of positioning surfaces thereof, while the neck mould is positioned in the axial direction in a resilient manner upon a neck mould support. In such an arrangement it is advantageous for the neck mould to be drawn axially towards the mould middle section so that the axial end position of the closed moulding tool is determined by the mould middle section. The axially exerted spring force is then smaller than the weight of the mould middle section. In any case the moulding tool is then closed in opposition to defined forces.
For the purpose of compensating for faulty alignment, it is possible in accordance with the invention to arrange the neck mould to be mounted for movement in the radial direction upon the neck mould support. This radial movement may also be under spring control, so that even when the moulding tool is in the open condition the neck mould will, under spring force, be centered in the normal radial position.
According to a further practical form of the invention, for the purpose of closing the moulding tool the mould middle section is arranged to engage over a portion of a block mould, or a parison mould bottom or a finishing mould bottom for the purpose of achieving relative three-dimensional positioning by the use of positioning surfaces, while the block mould, the parison mould bottom and the finishing mould bottom are spring mounted in the axial direction upon a support for the parison mould bottom member or upon a finishing mould bottom support. By this means advantages are gained which are analogous to those achieved by the spring controlled axial positioning of the neck mould.
Furthermore according to the invention the block mould, the parison mould bottom and the finishing mould bottom may be mounted for movement in the radial direction upon the parison mould bottom support or upon the finishing mould bottom support. Also these facilities for radial motion can be spring controlled to give advantages similar to those achieved in the spring mounting of the neck mould.
The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 to 5 schematically indicate parts of the mould middle section in various positions and phases of movement;
FIG. 6 is a longitudinal section through a finishing moulding tool along the line VI--VI in FIG. 7 on a somewhat enlarged scale;
FIG. 7 is a cross-section along the line VII--VII of FIG. 6 on a somewhat reduced scale;
FIG. 8 is a cross-section corresponding to that of FIG. 7 through a mould middle section with an operating device according to the lines VIII--VIII in FIGS. 9 and 10;
FIG. 9 is a sectional elevation along the line IX--IX of FIG. 8 on an enlarged scale;
FIG. 10 is a sectional elevation along the line X--X of FIG. 8 on an enlarged scale;
FIG. 11 is a partial longitudinal section of a part of a mould middle section in the open position and biased by means of a spring element;
FIG. 12 shows the arrangement according to FIG. 11 with the mould middle section in the closed position;
FIG. 13 shows a ball-type of holding closed force transmission element in section;
FIG. 14 shows a knife edge type of holding closed force transmission element in section;
FIG. 15 shows in partial section a plan view of a divided neck mould support;
FIG. 16 shows a sectional view along the line XVI--XVI of FIG. 15 on an enlarged scale;
FIG. 17 shows a longitudinal section through a parison moulding tool according to the invention;
FIG. 18 is a longitudinal section through a finishing mould bottom designed in accordance with the invention;
FIG. 19 is a partially broken sectional view along the line XIX--XIX of FIG. 20 of an operating device with a pivoting frame; and
FIG. 20 is the sectional view along the line XX--XX of FIG. 19.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 there is shown a part 30 of a mould middle section, in this case one-half of the mould middle section, having a center of gravity diagrammatically indicated at 33 and oppositely directed guide elements 35 and 36 of hook shape. By means of the upper guide element 35 the mould part is suspended upon a member 39 of an operating device or operating means, which is longitudinally displaceable in a support 40. With reference to a longitudinal axis 41 of a suitable cooperating moulding tool, clearance is provided between the member 39 of the operating device and the part 30 of the mould middle section on the one hand, as well as the two guide elements 35 and 36 on the other hand, this clearance being available both in the axial as well as the radial direction. This clearance is necessary also on account of the varying thermal expansions of these parts when in operation.
The clearance has the result that when the arrangement is in the rest position shown in FIG. 1 with the mould middle section 43 open, the part 30 of the mould middle section pivots in the counterclockwise direction until the upper outer portion of the guide elements 35 bears against the member 39 of the operating device, and at the lower end in the region of the guide element 36 the part 30 bears directly against the member 39 of the operating device.
If now the mould middle section 43 is to be closed from the rest position shown in FIG. 1, the member 39 of the operating device is moved to the left. In accordance with FIG. 2 a holding closed force transmission element 45 of the operating member 39 bears upon the part 30 of the mould middle section while, because of the particular position of the center of gravity 33, the part 30 of the mould middle section pivots in the clockwise direction into the position shown in FIG. 2.
In the further continuance of the closing movement, according to FIG. 3, the lower portion of the mould middle section part 30 comes into contact with another part 47 of the mould middle section. From this point the two parts 30 and 47 of the mould middle section mutually cooperate with each other in their directional movement until they reach the parallel closed position indicated in FIG. 4. In this position the part 30 of the mould middle section is suspended by its upper guide element 35 upon the member 39 of the operating device, while at the lower end there is clearance between the member 39 of the operating device and the guide element 36. By means of the operating device 39 the holding closed force transmission element 45 is forced against the mould middle section part 30 and thereby transmits to said part a holding closed force acting radially with respect to the longitudinal axis 41 and thereby acting in a holding closed force plane 50 directed at right angles to the longitudinal axis 41. This holding closed force has the same line of action but an opposed direction with respect to a resultant opening force due to the internal pressure acting upon the mould middle section part 30 and tending to open the mould middle section from the position shown in FIG. 4. Such opening movement is, however, effectively prevented.
After the conclusion of the moulding operation in the moulding tool, if the mould center section 43 is to be reopened from the closed operating position shown in FIG. 4, the member 39 of the operating device is moved to the right. This movement releases the holding closed force transmission element 45 from the respective part of the mould middle section and the member 39 of the operating device bears at the top and bottom against the guide elements 35 and 36 in its outward movement. At the end of the opening stroke the guide element 36 again releases itself from the member 39 of the operating device until the part 30 of the mould middle section has assumed its initial position according to FIG. 1.
In the case of the mould parts 30 and 47 shown in FIGS. 6 and 7, these are half middle sections of a finishing mould, which have positioning surfaces 53 and 54 engaging over complementary matching surfaces 56 and 57 of a neck mould 59 and a finishing mould bottom 60 respectively. To improve the clarity of the drawing, FIG. 6 shows both the neck mould 59 as well as the finishing mould bottom 60 out of engagement with the mould middle section 43 of the moulding tool 63. The neck mould 59 comprises a split neck moulding tool 65, the halves of which are indicated by 67 and 68.
Each part 30, 47 of the mould middle section is provided at an upper portion or at the top end with two peripherally spaced guide elements, for example 70, and likewise at a lower portion or at the bottom with two peripherally spaced guide elements, for example 71. The hook-shaped guide elements 70, 71 are pointed towards each other and at one side engage over the member 39 of the operating device and, in the case of the mould middle section 47, engage over a member 73 of an operating device 75. According to FIG. 7, the operating device 75 comprises two halves 78, 79 of a pair of tongs (by known means, not shown in the drawing) and pivotable about a common column 77. When in contrast with the position shown in FIG. 7, the halves of the tongs 78, 79 are opened, the parts 30, 47 of the mould middle section can be pivoted with respect to their longitudinal axis to enable them to be introduced into the member 39, 73 of the operating device, and similarly can be removed therefrom. The securing of the parts 30 and 47 of the mould middle section in the peripheral direction with respect to the operating device members 39, 73 is performed in each case by a locking device, for example 81. The locking device 81 is situated upon the operating device member 39 and includes a bolt 83, which is biased by a spring 85 towards the part 30 of the mould middle section. The bolt 83 engages in a bore 87 of the mould middle section part 30 with clearance on all sides thereof, that is to say with peripheral clearance which is not visible in FIG. 6. Accordingly, even when in the inserted position, the mould middle section part 30 is able to swing in the peripheral direction with respect to the bolt 83 to the extent of the peripheral clearance which is provided. This arrangement facilitates the relative adjustment of the parts 30, 47 of the mould middle section when closing the mould section 43.
Each member 39, 73 of the operating device applies a holding closed force by means of two respective block-shaped holding closed force transmission elements 90, 91 and 92, 93 respectively, these being effective at right angles to the longitudinal axis 41 of the moulding tool 63 within a common holding closed force zone 95 extending over an axial distance 97. The holding closed force transmission elements 90 to 93 are situated in spaced relationship in the peripheral direction.
In FIGS. 8 to 10 there is shown a practical form which has similarity with the practical form shown in FIGS. 6 and 7. Equivalent parts are therefore indicated by similar reference characters. Nevertheless, the members 39 and 73 of the operating device shown in FIG. 8 are applied against the two parts 30 and 47 of the mould middle section only by means of a single block-shaped holding closed force transmission element 100 and 101 respectively, these being effective in the holding closed force zone 95 indicated by dashed lines in FIG. 9. Over the entire remainder of the outer surface the members 39 and 73 of the operating device maintain a radial clearance with respect to the mould middle section 43.
In FIGS. 11 and 12 the part 73 of the operating device is fitted with a pressure means 105. The pressure means 105 comprise a pressure piston 107 radially penetrating the holding closed force transmission element 93 and having a piston rod 109 slidably guided in the member 73 of the operating device. Besides the pressure piston 107, a stack of spring washers 111 is arranged in a cavity 110 of the operating device member 73, the individual spring washers of the stack being freely displaceable axially upon the piston rod 109.
FIG. 11 shows the conditions when the mould middle section 43 is open. The pressure means 105 then forces the part 47 of the mould middle section by means of its guide elements 113 and 114 into continuous contact with the member 73 of the operating device so that all radial clearance between the member 73 of the operating device and the guide elements 113 and 14 is zero in the outward direction. The holding closed force transmission element 93 is then spaced away from the part 47 of the mould middle section by a radial clearance.
On the other hand, FIG. 12 shows the condition when the mould middle section 43 is closed. Then the holding closed force transmission element 93 bears upon the part 47 of the mould middle section in the holding closed force zone 95, while there is radial clearance on all sides between the part 47 of the mould middle section and the member 73 of the operating device.
In FIG. 13, spring means, e.g. 117, are provided to ensure that, both in the open as well as the closed position of the mould middle section 43, one or more peripherally distributed spherical holding closed force transmission elements, e.g. 119, always bear against the part 47 of the mould middle section in a holding closed force plane 120, whose position is indicated by a dashed line. The holding closed force plane 120 extends at right angles to the longitudinal axis, not shown in FIG. 13, of the assembled mounting tool. The spring means 117 comprises an enclosing pressure cap 123 and a stack 125 of plate springs, both of which are partially accommodated in a recess 127 of the member 73 of the operating device.
In FIG. 14 there is shown the member 73 of the operating device provided with a knife-edge type of holding closed force transmission element 130, whose knife edge bears against the mould middle section part 47 in the holding closed force plane 120.
In FIG. 15 there are shown the two halves 132 and 133 of a neck mould support 135; these being displaceably mounted upon two spaced rods 137 and 138. Each half 132, 133 of the neck mould support is provided with an approximately semicircular groove 140 and 141, in which engages a radial flange 143 of the neck mould 59 indicated by dash and dot lines in FIG. 16. Between the outer periphery of the radial flange 143 and the opposite wall of the groove 140 there is inserted a peripheral corrugated spring 145, which is yieldable to allow a certain amount of radial mobility of the neck mould 59 with respect to the neck mould support 135.
The neck mould 59 is, however, also resiliently movable in the axial direction with respect to the neck mould support 135. This facility is provided by two spring elements 146, 147; 148, 149 provided in respect of each half 132, 133 of the neck mould support.
FIG. 16 shows the condition when the moulding tool 63 is open. The half 67 of the neck moulding tool is suspended by its half of the radial flange 143 upon the spring elements 146 and 147, and is forced upwardly by these spring elements into contact with the opposing wall 150 of the groove 140. Thereby the half 67 of the neck moulding tool is accurately centered with respect to the appertaining half 68 of the neck moulding tool visible in FIG. 6, so that the closing of the entire moulding tool is substantially facilitated and proceeds with an extremely small amount of wear on the tool.
Stops 153 and 154, rigidly built into the halves 132, 133 of the neck mould support, and oppositely positioned releasable locking devices 156 and 157 hold the radial flange 143 of the halves 67, 68 of the neck moulding tool with the necessary clearance positioned in the grooves 140, 141 even when the moulding tool is in the open position.
The maximum radial clearance of the neck mould 59 with respect to the neck mould support 135 is indicated in FIG. 16 by the reference 159. The axial length of the spring path of the neck mould 59 with respect to the neck mould support 135 is indicated by 160.
Each spring element, e.g. 147, includes an upwardly directed spherical pressure cap 163, which supports itself upon a spring plate 167 by means of a prestressed helical spring 165, the spring plate itself being supported upon a locking ring 169 in the neck mould support 135.
When starting from the condition according to FIG. 16, the moulding tool is required to be closed, then the parts 30, 47 of the mould middle section, e.g. according to FIG. 6, are approached towards each other and bring their positioning surface 53 into engagement over the opposing surface 56 on the neck mould 59. By reason of the comparatively weak bias of the helical springs 165, the neck mould 59 is thereby drawn slightly downwardly in an axial direction until the position is reached in which there is secure positive clamping between the mould middle section 43 and the neck mould 59.
In FIG. 17 the neck mould 59 includes, besides the neck mould halves, e.g. 67, an undivided guide ring 175 for a press plunger 177. The plane of division between the two halves of the neck moulding tool lies in the plane of the drawing of FIG. 17.
A moulding tool 180, which is in fact a parison mould, comprises in addition to the neck mould 59, a divided mould middle section 181, the parts of which, e.g. 183, are respectively suspended in an operating device member, e.g. 185. Similar to the arrangement in the previously described practical forms, the transmission of the holding closed force into the mould middle section 181 is effected by means of block-shaped holding closed force elements, e.g. 187, belonging to the operating device members, e.g. 185. The section portions taken to the left and right outwardly on the mould center section 181 and the operating device member 185 are shown turned into the plane of the drawing.
At the lower end the mould middle section 181 engages over a block mould 190, which by means of an annular face 191 bears upon a support ring 193 of a block mould support 195 when the moulding tool 180 is in the open position. An undivided clamping ring 197 overhangs an annular shoulder 199 of the block mould 190 and is provided with three uniformly spaced peripheral cavities 200, only one of which is shown at the right side of FIG. 17, in each of which is housed a spring element 203. Each spring element 203 comprises a pressure piston 207 backed by a piston rod 209 and forced by the bias of a stack 205 of spring washers against the annular shoulder 199.
Three tie rods 210, only one of which is shown at the left side of FIG. 17, are uniformly spaced about the periphery holding the clamping ring 197 at a constant axial distance from the block mould support 195, and are each locked with respect to the clamping ring 197 by a locking bar 213.
When the moulding tool 180 is required to be closed, the mould middle section 181 is then closed by means of the operating device members, e.g. 185, and thereby engages over the neck mould 59 at the top and over the block mould 190 at the bottom. In this closing operation the block mould 190 is lifted in the axial direction from the support ring 193 by a distance 215. Because this distance 215 is smaller than the distance 217, which is under spring control, between the clamping ring 197 and a locking ring 219 of the piston rod 209, the block mould, when the moulding tool 180 is in the open position, has its annular face 191 pressed against the support ring 193 by the action of the spring elements 203.
In FIG. 18 a finishing mould bottom 230 is shown inserted in a support ring 231. In each of three bores 233 uniformly spaced about the periphery of the support ring 231 (only one of the bores is shown in FIG. 18) there is fitted a pin 235. In the open condition of the moulding tool, a shoulder 237 of the finishing mould bottom 230 rests upon pins 235. An annular spring plate 239 is locked against rotation with respect to the finishing mould bottom 230 by means of a pin 240, and bears against the lower side of the three pins 235. The spring plate 239 is provided around its periphery with three mounting slots 241, only one of which is shown in FIG. 18, whose angular positions correspond to those of the pins 235, and which, when in coincidence, provide for a bayonet-type connection of the finishing mould bottom 230 into the support ring 231. As soon as this connection is completed a locking device 245, corresponding to the locking device 81, is operated and its pin 247 engages in an axial groove 249 of the finishing mould bottom 230 with clearance on all sides.
A locking ring 250 of the finishing mould bottom 230 supports a cap 251, between which and the spring plate 239 there is arranged a biased stack 253 of spring washers. Between the cap 251 and the spring plate 239 there is defined the maximum axial path 255 of spring movement between the finishing mould bottom 230 and the support ring 231.
The support ring 231 is provided at its top end with an annular flange 260, which is arranged to be a sliding fit between a finishing mould bottom support 261 and a mounting ring 263 threaded over said support. The mounting ring 263 carries the locking device 245. By the provision of the above-mentioned sliding fit it is possible for the support ring 231 with the finishing mould bottom 230 to have a certain radial movement with respect to the finishing mould bottom support 261 and its mounting ring 263, and in this way to compensate for any eventual alignment faults between the finishing mould bottom 230 and the other components of the appertaining moulding tool.
In FIGS. 19 and 20 there is shown a mould middle section 270 in the closed condition, but without any neck mould and finishing mould bottom. Each part of the mould middle section, e.g. 271, is suspended by means of two guide elements 273 and 274 upon two block-shaped holding closed force transmission elements 276 and 277 of a pivoting frame 279, which elements engage the mould middle section parts 271 over a common holding closed force zone 281 extending at right angles to a longitudinal axis 280 of the moulding tool and having an axial dimension 283. An oppositely directed hook-shaped guide element 285 engages from below over a third centrally located holding closed force transmission element 287, which transmits its own component of the total holding closed force over a holding closed force zone 289 also indicated by the dashed lines, directed at right angles to the longitudinal axis 280 and having the axial dimension 290.
The pivoting frame 279 is a component of an operating device member 293, which also includes a carrier 295 with a ball socket 297 for a ball 299 of the pivoting frame 279. The ball 299 and the ball socket 297 form a joint or force transmitting means 300. The carrier 295 is split along a plane 301 parallel to the longitudinal axis 280 for mounting the ball 299. The parts of the carrier are connected together by screws, whose center lines are indicated at 302 in FIG. 20.
The carrier 295 is provided with two cavities 303 and 304, into each of which there is inserted a respective pressure cap 307 and 308 and a plate spring stack 310 and 311 respectively. In the carrier 295 there is threaded an adjusting screw 313, against which there is supported the one end of the plate spring stack 310. By means of the adjusting screw 313 it is possible to adjust the pivoting frame 279 into a defined rest position. For example, it is possible in this way to make the initial bias of the plate spring stack 311 greater than that of the stack 310.
A resultant holding closed force component 315 exerted by the operating device member 293 upon the mould middle section 291 is directed through the center point of the ball 299 and in the line of action of a resultant opening force component 317 exerted upon the mould middle section part 271. This resultant holding closed force 315 is transmitted by three components through the respective holding closed force transmission elements 276, 277 and 287 into the mould middle section part 271.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of moulding tools differing from the types described above.
While the invention has been illustrated and described as embodied in a moulding tool for plastic material, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.
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A moulding tool for a machine for moulding plastic material, especially molten glass, comprises at least one mould middle section divided into a plurality of middle section parts, and operating means having members each carrying with clearance a respective one of the mould middle section parts for opening and closing movements transversely of the longitudinal axis of the mould and transversely guiding the parts in two axially spaced guide planes by means of guide elements.
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TECHNICAL FIELD
This is a continuation-in-part of application Ser. No. 07/945,319 filed Sep. 15, 1992, by the same inventor now U.S. Pat. No. 5,354,743.
BACKGROUND OF THE INVENTION
This invention relates to a method for reducing or relieving symptoms associated with premenstrual syndrome (“PMS”) by administering to an individual exhibiting PMS symptomology a therapeutically effective amount of a combination of calcium and vitamin D.
BACKGROUND OF THE ART
Symptoms generally experienced by women with PMS, the occurrence and exaggeration of mood and behavioral disturbances in women during the latter half of their menstrual cycle, without limitation include (1) somatic symptoms such as abdominal cramps, headaches including vascular headaches such as migraine headaches, breast fullness and tenderness, back pain and bloating and (2) psychological symptoms such as, depression, irritability and anxiety. While these symptoms, which are among those generally related to PMS, do not occur solely in women with PMS, it has been estimated that as much as 90% of all premenopausal women exhibit some degree of symptoms such as those above related to PMS, ranging from mild to incapacitating, and that about 7 million women suffer severe and incapacitating symptoms related to PMS.
U.S. Pat. No. 4,946,679 of Thys-Jacobs and the article by Thys-Jacobs et al. entitled “Calcium Supplementation in Premenstrual Syndrome. A Randomized Crossover Trial”, J. Gen. Int. Med., 1989:4:183, showed that elemental calcium is effective in significantly reducing symptoms associated with PMS when administered, for example, in a daily dose of 1000 mg for 3 months. Thys-Jacobs et al. reported a 50% reduction in PMS symptomology for the daily administration of elemental calcium in the dose of 1000 mg for three months. Similarly, Chuong et al., in an abstract presented at the American Fertility Annual Meeting in 1991 entitled “Calcium Levels in Premenstrual Syndrome” showed that women with PMS had significantly lower calcium levels during the luteal phase of the menstrual cycle as compared with asymptomatic controls and also showed that women with PMS had significantly lower calcium levels during the luteal phase of the menstrual cycle as compared to the follicular phase of the menstrual cycle.
However, there still exists a need for therapy that provides further reduction or relief of symptoms associated with PMS, especially in particularly persistent cases.
SUMMARY OF THIS INVENTION
An object of this invention is to reduce or relieve symptoms associated with PMS in an individual exhibiting such symptoms, especially in those patients who do not demonstrate improvement when treated with calcium alone.
The present invention is directed to a method of at least reducing symptoms associated with PMS. A therapeutically effective amount of a combination of calcium and vitamin D is administered to an individual exhibiting symptomatology associated with PMS.
DETAILED DESCRIPTION OF THE INVENTION
The method of the present invention treats individuals exhibiting symptoms associated with PMS by the administration of a therapeutically effective amount of a combination of calcium and vitamin D. Preferably, the dosage of elemental calcium administered is in the range of from about 1000 mg to about 2000 mg per day. Preferably, the dosage of vitamin D administered is in the range of from about 400 to about 2000 IU per day. Preferably, the dosage of vitamin D elevates 25 hydroxyvitamin D levels to levels greater than 30-40 ng/ml. The calcium and vitamin D may be administered concurrently such as, for example, by administration of a tablet, a capsule, a powder, liquid, candy or mint, cookie or food additive containing the desired dosages of the calcium and the vitamin D. Preferably, the combination is administered orally in the form of a tablet. Calcium may be administered in the form of calcium carbonate, calcium gluconate, calcium citrate, calcium phosphate, calcium chloride, calcium stearate or calcium acetate, and preferably in the form of calcium carbonate. Vitamin D may be administered as at least one of vitamin D 2 (ergocalciferol), vitamin D 3 (cholecalciferol) or 25 hydroxyvitamin D (calcidiol or calcifediol). The dose can be taken as a single daily combination dose or in split doses of smaller concentrations in adequate levels for prevention of PMS symptoms. Examples of combinations for single doses are as follows:
Elemental calcium
Vitamin D 2 or D 3
1000
mg
400
IU
1000
mg
600
IU
1000
mg
800
IU
1200
mg
400
IU
1200
mg
600
IU
1200
mg
800
IU
1200
mg
1000
IU
1200
mg
1200
IU
1500
mg
400
IU
1500
mg
300
IU
1500
mg
800
IU
1500
mg
1000
IU
1500
mg
1200
IU
1500
mg
2000
IU
Examples of smaller concentration embodiments to be administered at least 2 to 3 times daily are as follows:
Elemental calcium
Vitamin D 2 or D 3
300
mg
200
IU
300
mg
250
IU
500
mg
200
IU
500
mg
300
IU
500
mg
400
IU
600
mg
300
IU
600
mg
400
IU
600
mg
500
IU
600
mg
600
IU
700
mg
700
IU
800
mg
400
IU
800
mg
800
IU
800
mg
800
IU
2000
mg
2000
IU
The combination is effective for reducing or relieving symptoms associated with PMS, which include somatic symptoms such as without limitation headaches, especially vascular headaches such as migraine headaches, tenderness and swelling of the breasts, abdominal bloating, abdominal cramping, generalized aches and pains, lower backache, fatigue, increased/decreased appetite, craving for sweet/salt, swelling or edema of extremities and insomnia and which include psychological symptoms such as mood swings, depression, tension, anxiety, anger and crying spells.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed non-limiting examples of the present invention.
EXAMPLE 1
Applicant's Research Study Indicating That Many Women With PMS Have A Vitamin D Deficiency
1.1 Enrollment of Participants
The study herein described was conducted at Mount Sinai Hospital in New York City. Women working and residing in the New York area with a self-diagnosis of PMS were recruited.
From those women reporting a self-diagnosis of PMS, women were further selected if they fulfilled a strict definition of premenstrual syndrome: Cyclically recurring symptoms during the luteal phase of the menstrual cycle which subside with the onset of menstruation. Determination of recurrence of symptoms was based on a prospective and consecutive two month daily diary. Each woman was asked to complete daily pre-trial self-assessment questionnaires where 17 symptoms were measured and recorded daily over one menstrual cycle. Each was instructed to complete one questionnaire every evening, describing how she felt during the previous 24 hours by recording her level of symptom severity for each of the seventeen symptoms. The 17 symptoms evaluated were: mood swings, depression, tension, anxiety, anger, crying spells, tenderness and swelling of breasts, abdominal bloating, abdominal cramping, generalized aches and pains, low backache, headache, fatigue, increased/decreased appetite, cravings for sweet/salt, swelling/edema of extremities and insomnia. Each symptom was marked daily on a four-point scale (absent, mild, moderate, severe) and subsequently scored from 0 to 3. Women were further selected if their mean symptom scores from the latter seven days of the luteal phase were at least 50% greater than the seven days following the days of menstruation.
Criteria for exclusion from the clinical trial were: (1) history of renal disease, (2) history of primary hyperparathyroidism, (3) history of liver or gastrointestinal disease, (4) history of endometriosis, (5) history of psychosis and (6) active depression.
22 women were finally selected for this study. A preliminary evaluation on each finally selected woman (“patient”) included (1) a standardized medical evaluation with a detailed gynecological history as well as a routine physical examination and (2) a determination of complete blood count, electrolytes, alkaline phosphatase, albumin, glucose and urinalysis. All determinations of the above were within normal laboratory limits as set by the laboratory performing the determinations.
1.2 Study
For all women baseline levels for calciotropic hormones 1,25 dihydroxyvitamin D [1,25(OH) 2 D], 25 hydroxyvitamin D [250HD] and intact parathyroid hormone (iPTH) were determined at the midpoint in the menstrual cycle. Additionally, baseline calcium levels were determined at the midpoint in the menstrual cycle. All determinations and evaluations of serum samples were performed by a single central laboratory, Nichols Institute of California.
Serum samples for the 1,25(OH) 2 D assay were extracted with acetonitrile and purified by Sep-pak C-18 and Sep-Pak silica columns. The purified 1,25(OH) 2 D was assayed in a radioreceptor assay using calf thymus and 3 H-1,25(OH) 2 D.
The serum samples for the 250HD assay, like the 1,25(OH) 2 D samples, were extracted with acetonitrile and purified through C-18 Sep-Pak columns. The purified 250HD sample was assayed in a radiobinding assay using 3 H-250HD and rat serum binding protein.
The intact parathyroid hormone assay is a two site immunoradiometric assay (IRMA). The IRMA employs two kinds of anti sera, one is specific to the C-terminal portion of the molecule and the other is specific to the N-terminal end. The assay measures only the intact hormone.
The serum samples for total calcium were assayed by atomic absorption spectrometry.
The results are shown below in Table 1. Normal values for the calciotropic hormones 1,25(OH) 2 D, 250HD and intact parathyroid hormone (iPTH) and calcium are shown below in Table 2.
TABLE 1
CALCIOTROPIC HORMONES IN WOMEN
WITH PREMENSTRUAL SYNDROME
250HD
T.calcium
iPTH
1,25(OH) 2 D
Patient
Cycle Day
ng/ml
mg/dl
pg/ml
pg/ml
001
14
18
9.6
71
46
002
12
17
9.6
46
60
003
15
20
8.7
70
38
004
13
24
9.5
25
51
005
12
17
9.1
68
<5
006
15
16
9.6
49
52
007
15
16
8.8
30
69
008
13
17
8.9
86
75
009
17
27
9.3
61
57
010
16
24
8.9
60
36
011
13
33
9.4
54
46
012
14
25
9.4
50
46
013
14
19
9.4
65
44
014
15
27
9.8
66
50
015
13
21
9.3
47
84
016
13
27
10.0
26
40
017
15
23
9.0
21
21
018
14
27
9.6
31
51
019
14
35
9.3
39
63
020
14
24
9.3
21
54
021
15
21
8.9
48
15
022
15
21
9.0
32
32
Cycle day refers to the day of the menstrual cycle when the serum sample was drawn.
T.calcium refers to total calcium.
TABLE 2
NORMAL CALCIOTROPIC HORMONE VALUES
AS DETERMINED BY LABORATORY
250HD
T.calcium
iPTH
1,25(OH) 2 D
ng/ml
mg/dl
pg/ml
pg/ml
Normal
9-52
8.8-10.4
10-65
15-60
Values
1.3 Discussion of Lab Results
Only one patient was determined to be hypocalcemic. Five women were determined to have elevated iPTH determinations, while five were determined to have abnormal 1,25(OH) 2 D levels with four elevated and one undetectable. All were determined to have normal 250HD levels. Thus, a total of ten women were determined to have abnormally elevated iPTH or 1,25(OH) 2 D determinations when these measurements were drawn at the midpoint of the menstrual cycle. It has been mentioned by Nordin et al. in an article entitled “Osteoporosis and Osteomalacia” in Clin. Endocrinal Metab., 1980; 9; 177-205 that a raised iPTH level might indicate a vitamin D deficiency. Five women were determined to have elevated iPTH levels and might be considered vitamin D deficient. However, elevated iPTH is a necessary but not a sufficient condition to absolutely diagnose a vitamin D deficiency.
1.4 Treatment
Each woman was instructed to take daily supplementation with 600 to 2000 IU per day of vitamin D 2 or D 3 and 1200 mg to 1500 mg per day of elemental calcium.
1.5 Results
Daily supplementation with vitamin D in doses of 600 to 2000 IU per day and with elemental calcium in doses of 1200 mg to 1500 mg per day resulted in a significant relief of PMS symptomology. Within months this therapy resulted in an elevation of the 250HD level above 30-40 ng/ml, and for those women with abnormal calciotropic values as defined by the laboratory, such values were corrected to within normal determinations. To prevent recurrence each was instructed to continue lifetime vitamin D and calcium supplementation.
EXAMPLE 2
Case Studies Applying Applicant's Research Finding
2.1 Patient X
Patient X is a 47 year old female with a 20 year history of PMS. Her major symptoms included severe irritability, mood swings, breast swelling and tenderness, and menstrual cramps. Vascular headaches, specifically common migraines (or migraines without aura), frequently interfered with her functional well being during both the premenstrual and menstrual phases of her menstrual cycle. She occasionally suffered with classic migraines (or migraines with aura) at least 4 to 5 times a year. Her common migraines were characterized by a pulsating quality of severe intensity lasting 2-3 days, associated with photophobia, nausea, occasional vomiting, and exacerbated by routine physical activity. These migraines were temporally related to the onset of her menstrual period and were always associated with her PMS symtomatology. Her past medical history was significant for mild hypertension, polycystic kidney disease, mitral valve prolapse with mitral regurgitation, recurrent vaginitis, and amenorrhea 22 years ago. She had a very strong family history of breast cancer with a mother, aunt and sister all diagnosed with cancer. She is at major risk for the development of breast cancer with such a strong family history of breast cancer, a personal history of cyclical mastopathy, and a residence in the New England region. She requires an annual mammogram and breast examination for cancer screening.
Calciotropic hormone levels in this patient:
4/92: total calcium 8.5 mg/dl (8.6-10.1)
iPTH—8.5 pmol/L (1.0-6.8)
250HD—14 mcg/L (10-80)
1,25(OH) 2 D—30.3 ng/L (18.0-62.0)
7/92: total calcium 9.10 mg/dl (8.6-10.1)
11/92: total calcium 9.00 mg/dl (8.6-10.1)
iPTH—7.3 pmol/L (1.0-6.8)
250HD—30.3 mcg/L (10.0-80.0)
1,25(OH) 2 D—50.1 ng/L (18.0-62.0)
2/93: total calcium 9.70 mg/dl (8.6-10.1)
iPTH—4.30 pmol/L (1.0-6.8)
250HD—34.5 mcg/L (10-80)
She was diagnosed with PMS by history, by prospective charting of symptoms and by a luteal to intermenstrual ratio of greater than 150%. Laboratory results confirmed hypocalcemia with a secondary hyperparathyroidism and a normal 250HD. In 4/92, she was treated with elemental calcium in the dose of 1200 mg/day and continued on her daily multivitamins (which included a low dose of elemental calcium and the RDA for vitamin D). Over the next 2 months, this resulted in complete correction of her hypocalcemia, but only partial relief of her premenstrual irritability and menstrual cramps. She was then prescribed 400 additional IU of cholecalciferol, while elemental calcium was increased to 1500 mg per day. Her vascular headaches persisted, and she still complained of nocturnal menstrual cramps. In 11/92, her total calcium was normal, her iPTH was elevated and her 250HD remained normal as defined by the laboratory. She was prescribed 1000 IU of cholecalciferol per day and maintained on 1500 mg of elemental calcium per day in addition to her daily multivitamin (total vitamin D intake therefore amounted to 1200 IU). On this regimen, her iPTH normalized, her 250HD increased to 34.5 mcg/L and her symptoms resolved. In addition, her blood pressure normalized. By recommending appropriate doses of vitamin D and calcium, and maintaining the 250HD level above 35.0 mcg/L with semiannual determinations, symptomatology was prevented.
2.2 Patient Y
Y is a 47 year old female with a history of Rheumatic fever, mild hypertension and a 30 year history of PMS. She presented with severe premenstrual and menstrual symptomatology occurring 10 to 14 days prior to the onset of her menstrual period. Her symptoms consisted of anxiety, extreme nervousness, breast tenderness and fullness, abdominal bloating, body aches, lack of energy, vascular headaches, and severe menstrual cramps. Her symptoms were of such severity that her co-workers at her job ostracized her, and criticized her monthly abnormal behavior. With prospective charting of the daily symptoms described in Example 1.1 (less insomnia) over two menstrual cycles, PMS was confirmed. Her luteal mean score was 48 (the maximum achievable score). Baseline total calcium was 9.9 ng/ml (8.8-10.4), 250HD was 24 ng/ml (9-52) and iPTH was 54 pg/ml (10-65). Laboratory determinations showed that she had a serum calcium that was normal as defined by the laboratory, a vitamin D level that was normal, and a iPTH that was normal. Prescribed daily treatment with 1200 mg of elemental calcium and 800 IU of cholecalciferol completely resolved her headaches, abdominal cramps, irritability, lethargy, breast tenderness/fullness, and behavioral changes.
The present invention is not to be limited in scope by the embodiments disclosed in the examples which are intended as illustrations of aspects of the invention. Any methods which are functionally equivalent are within the scope of this invention. Indeed, various modifications of the invention in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description. Such modifications are intended to fall within the scope of the appended claims.
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The present invention is directed to a method for treating symptoms associated with premenstrual syndrome. The method comprises administering to an individual in need of treatment an amount of a combination of elemental calcium and vitamin D effective to reduce the symptoms associated with premenstrual syndrome.
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BACKGROUND
[0001] The present disclosure is related in general to wellsite equipment such as oilfield surface equipment, downhole assemblies, and the like.
[0002] The present disclosure relates generally to pump down conveyance of wireline and/or slickline tools including, but not limited to, the conveyance of perforating guns.
[0003] Generally, this disclosure describes methods for improving the efficiency of pump down operations in wellbores having longer horizontal sections and/or higher curvature, deviated, and/or horizontal wellbores.
[0004] One of the problems encountered while conveying downhole tools by pumping them down in the well is the unintentional pull off of the wireline or slickline cable at the weak point at the top of the toolstring. A weak point is highly desirable in cases where the toolstring becomes stuck in the well, and must be retrieved with a fishing tool. The weak point is installed to ensure that when over-pulling on the cable, the weak point breaks at the top of the toolstring if the toolstring is stuck, such that the cable may be removed from the well before fishing. The more extended the reach of the well is, the higher the tension of the cable must be to exceed the frictions forces between the cable and the sidewall of the well, and therefore the lower the tension rating of the weak point must be to insure mechanical integrity of the cable over its entire length. Lowering the tension rating of the weak point makes unintentional pull off more likely when the tool is pumped down.
[0005] It remains desirable to provide improvements in oilfield surface equipment and/or downhole assemblies.
SUMMARY
[0006] An example method of conveying downhole equipment includes providing pressure to a wellbore to convey a toolstring connected with a cable; and measuring tension in the cable proximate a top of the toolstring; wherein if the toolstring is being conveyed the toolstring remains connected with the cable regardless of measured tension in the cable proximate to the top of the toolstring, and wherein if the cable is being retrieved the downhole equipment is released from the cable if the measured tension in the cable proximate the top of the toolstring is too large.
[0007] An example system for monitoring and controlling a downhole operation includes a toolstring connected with a cable by a release device. The release device is configured to release the toolstring from the cable upon receipt of a release signal from the control logic. The system also includes a sensor operatively located adjacent a top of the toolstring for measuring tension in the cable.
[0008] The system can also have control logic in communication with the release device and the sensor. The control logic is configured to send the release signal to the release device during deployment of the toolstring if the sensor measures tension in the cable that is too large.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 depicts an embodiment of a system for pump down conveyance.
[0010] FIG. 2 depicts flow diagram of a method of pump down conveyance.
[0011] FIG. 3 depicts a general schematic of a method of monitoring and controlling a downhole operation.
[0012] FIG. 4 depicts another schematic of an embodiment of a method of conveying and retrieving downhole equipment.
[0013] FIG. 5 depicts a toolstring in a wellbore.
DETAILED DESCRIPTION OF THE INVENTION
[0014] Certain examples are shown in the above-identified figures and described in detail below. In describing these examples, similar or identical reference numbers are used to identify common or similar elements. The figures are not necessarily to scale and certain features and certain views of the figures may be shown exaggerated in scale or in schematic for clarity and/or conciseness.
[0015] An example method of pump down conveyance includes lowering in a well a toolstring connected to a cable by applying pressure to a pump down head via a pump located at a wellbore surface; measuring a cable tension at a downhole location proximate the top of the toolstring; transmitting the measured cable tension to an operator at the wellbore surface; unlatching the cable from the toolstring if the downhole cable tension is above a threshold when the toolstring is reeled in; and not unlatching the cable from the toolstring even if the downhole cable tension is above the threshold when the toolstring is pumped down. Detaching the cable from the toolstring may be performed by sending a command to an electrically controlled release device.
[0016] Another example method can include controlling the rate of the pump based on the downhole cable tension. The method may also include measuring a cable tension at a surface location proximate the winch, and controlling the rate of the pump and the rotation of the winch based on the downhole and surface cable tensions.
[0017] Controlling the pump or the winch may be automated and performed by an electronics controller, or the operation and control of the pump or the winch may be performed by an operator.
[0018] The control may be performed by an operator making decision in view of data displayed on a monitor, or it may be performed automatically by a controller, utilizing suitable equipment for monitoring data and controlling surface equipment or the like.
[0019] The control inputs comprise downhole data, for example measured by sensors disposed proximate the top of the toolstring, such as in the logging head. Typically, downhole data may comprise downhole cable tension measured at the logging head. Other downhole data can include wellbore pressure, wellbore temperature, etc., as will be appreciated by those skilled in the art with the aid of this dislcsoure.
[0020] The control inputs may also comprise surface data, for example measured by sensors disposed at the well site. Typically, surface data include winch direction (or winch speed). Other surface data may also include uphole cable tension measured at the winch, the rate of the pump used to pump the toolstring down, and pressure at the pump.
[0021] The control logic utilizes downhole and surface data, so the data are gathered in one convenient location, typically at the surface. For example the downhole data are telemetered and displayed to the operator and/or gathered by the controller, together with the surface data.
[0022] The control outputs include downhole commands, for example sent to downhole actuators disposed proximate the top of the toolstring, such as in the logging head. Downhole commands may be sent to an electrically controlled release device. Other downhole commands could be sent to an unsticking device or another downhole device as part of the toolstring.
[0023] The control outputs may also include commands sent to surface actuators disposed at the well site. The control outputs could include commands sent to the pump used to pump the toolstring down or to the winch.
[0024] FIG. 1 depicts an embodiment of a system for pump down conveyance.
[0025] The system 100 can include a logging head 110 . The logging head 110 can have any number of sensors. The sensors can be for measuring downhole tension in the cable or other parameters related to downhole parameters of the toolstring, cable, or wellbore. The downhole parameters can be acceleration of the toolstring, wellbore pressure, wellbore temperature, or the like. The toolstring may also be referred to herein as a downhole tool. The toolstring can have any number of components or tools connected together.
[0026] A release device 114 can be connected with the logging head 110 . The logging head 110 can also be connected with a telemetry module 112 . The telemetry module 112 is in communication with the sensors of the logging head 110 and the release device 114 .
[0027] A control 120 with control logic 122 can be in communication with the telemetry module 112 , a pump motor 136 , a pump 130 , a winch 132 , and a winch motor 134 . The control logic 122 can be configured to perform any of the methods described herein.
[0028] An operator 140 can see operation conditions on a display 141 . In an embodiment, the operator 140 can use the information on the display 141 to control the conveyance and retrieval of the toolstring. In another embodiment, the control logic can receive information from the sensors, pump motor 136 , pump 130 , winch 132 , winch motor 134 , and use that data to control the conveyance and retrieval of the toolstring.
[0029] FIG. 2 depicts flow diagram of a method of pump down conveyance. T
[0030] The method 200 includes measuring downhole tension (Block 210 ). The downhole tension can be measured using a sensor that is proximate to the toolstring. The sensor can send a tension signal a controller and the controller can use calibration data to determine the downhole tension.
[0031] The method 200 also includes determining if the downhole tool is being pump down or reeled in (Block 213 ). For example, the controller can receive a signal from an operator indicating if conveyance or retrieval is occurring, or in another embodiment a sensor such as an accelerometer can be send a direction signal to the controller, which can used preinstalled calibration data to determine if conveyance or retrieval is occurring.
[0032] The method 200 also includes comparing downhole tension to threshold tension (Block 215 ) if the downhole tool or toolstring is being retreived; however, if the downhole tools is being conveyed the method loops back to measuring downhole tension (Block 210 ). The threshold tension can be a predetermined working break strength for the cable. The threshold tension can change as the toolstring moves through the well; therefore, the control can use know techniques and methods to dynamically determine the threshold tension.
[0033] The method also included unlatching the release device (Block 217 ) if the downhole tool is likely stuck or cable failure is likely; however, if the comparison indicates cable failure risk is low then the method loops back to measuring the downhole tension (Block 210 ). Unlatching the release device can include sending a signal to the release device when the downhole tension is larger than the threshold tension.
[0034] FIG. 3 depicts a general schematic of a method of monitoring and controlling a downhole operation.
[0035] The method 300 includes determining downhole tool movement (Block 310 ). The movement of the downhole tool (pumped down or reeled in) can be determined by utilizing the winch speed or other sensors. The method also include determining tension along the cable (Block 310 ). The tension along the cable can also be computed. The tension along the cable can change. For example, the tension changes depending on the tool movement, change in the direction of drag forces, and location of the tool in the well. To compute the tension, data other than the tool movement may be used, such as, but not limited to, uphole and/or downhole cable tension, pressure applied to pump down head, pump pressure at the well site, or the like, as will be appreciated by those skilled in the art.
[0036] Based on the cable tension computed along the cable, the method can include changing winch speed (Block 330 ), changing pump rate (Block 340 ), Unlatching the release device (Block 350 ), and/or unsticking the downhole tool (Block 360 ). For example, control logic can determine if the winch speed and/or the pump rate should be modified to prevent cable failure or to increase the speed of the tool as it progresses along the wellbore. Also, the control logic can determine if the electrically release device should be unlatched, and/or if an unsticking device should be actuated. The control logic can use predetermined operational parameters, calibration data, cable data, and predetermined mathematical formulas to make the control determinations.
[0037] As an example of the generalized logic. When reeling in, the cable tension increases towards the surface, either because of cable drag in the deviated section, and/or because of cable weight in the horizontal section. The point of highest cable tension is usually uphole, and the decision to unlatch the ECRD may be taken or initiated based on the uphole cable tension measured at the winch and a cable failure threshold. The threshold may be updated to take into account uncertainty in the drag forces on the cable, to increase a safety margin in case of debris or the like.
[0038] When pumping down, the cable tension may decrease towards the surface in the deviated section because of cable drag, and increases again towards the surface in the horizontal section because of cable weight. The point of highest cable tension is usually downhole, and the decision to unlatch the ECRD may be taken based on the downhole tension measured at the logging head and a cable failure threshold. The threshold can be updated to take into account uncertainty in the drag forces on the cable, or the like.
[0039] FIG. 4 depicts another schematic of an embodiment of a method of conveying and retrieving downhole equipment.
[0040] The method 400 can include determining if the downhole tool is being pumped down or reeled in (Block 410 ).
[0041] Upon a determination that the downhole tool is being pumped down the method includes measuring downhole tension (Block 412 ) and updating pump down-threshold (Block 414 ). Measuring downhole tension and updating the pump down-threshold can be done using techniques disclosed herein or other techniques that are now known or known in the future. These techniques and implantation thereof would be known to one skilled in the art with the aid of this disclosure. The method also includes comparing downhole tension to pump down-threshold (Block 416 ). The method 300 can loop back to determining if the downhole tool is being pumped down or reeled in (block 410 ) when cable failure risk is low, or the method 300 can include unlatching a release device (Block 430 ).
[0042] Upon a determination that the downhole tool is being reeled in, the method 300 includes measuring the uphole tension (Block 420 ) and updating the reeled-in threshold (Block 424 ). The method also includes comparing uphole tension to reeled-in threshold (Block 426 ). Upon a determination that there is no cable failure risk the method loops back to (Block 410 ); however, if cable failure risk is determined the method continues to (Block 420 ).
[0043] FIG. 5 depicts a toolstring in a wellbore.
[0044] The toolstring 504 can be conveyed into a wellbore 502 using pump down head provided by pump 520 . The toolstring 504 can be connected with a cable 510 . The cable 510 is connected to a winch 511 . The winch 511 and cable 510 can be used to retrieve the toolstring 504 . The tension on the cable will be higher near the toolstring 504 during pump down and near the surface during retrieval. The tension on the cable can change depending on the wellbore shape, the pump down rate, and other factors. For example, when pumping down the cable tension decreases towards the surface in the deviated section because of cable drag, and increases again towards the surface in the horizontal section because of cable weight.
[0045] Although example assemblies, methods, systems have been described herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers every method, apparatus, and article of manufacture fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents.
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A cable that includes outer cable jacketing located about a conductor layer. The conductor layer includes cable elements that are resistant to compression and a plurality of compression-resistant members.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of pending International Application No. PCT/EP2015/055580 filed on Mar. 17, 2015 and now published as WO 2015/140180, which designates the United States and claims priority from German Application No. 10 2014 103 666.2 filed on Mar. 18, 2014. The disclosure of each of the above-identified patent documents in incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a door handle, e.g. to a doorknob, with a door-side output shaft and a handle facing away from the door leaf, wherein the output shaft and the handle have a common rotation axis and are connected by a preferably electromechanical clutch, so that with an open clutch the handle may be operated, i.e. may be rotated, without entraining the output shaft. With a closed clutch, however, the handle and the output shaft are non-rotatably connected with each other.
[0004] 2. Description of Relevant Art
[0005] In Europe, so-called case locks are generally used in doors, which are also known as mortise locks. Mortise locks are inserted into a recess in the narrow side of the door which is revealed when opening of the door, and are fixed there. These mortise locks have a latch and usually a dead bolt (bolt, for short). At least the latch may usually be retracted by a door handle (mostly in a form of a doorknob) to open the door. In so-called anti-panic locks, also the dead bolt is coupled with the handle, such that also this bolt is retracted upon actuation of the handle. To initiate the rotational movement of the door handle in the mortise lock, the mortise lock has a so-called nut, in which usually a square shaft extending orthogonally to the door leaf is inserted, such that it protrudes at least on one side over the door leaf. The nut is thus some sort of socket for (e.g. form fittingly) receiving the shaft. The door handle is then placed on this free end in a rotationally locked manner.
[0006] Locking or unlocking the door is usually done by so-called cylinder locks, which are inserted in the mortise locks. The cylinder locks have a locking cam arranged on a shaft, which cam interacts with the mortise lock. The locking cylinder allows rotation of the locking cam by a user, provided the user is authorized, whereby either a key or a knob serves for actuating the locking cam by the user.
[0007] Electromechanical locking systems are based on the electronic identification of a key. The key may be, for example, an active or passive transponder. A lock control exchanges data with the key, thereby checks the authorization of the key, and possibly releases the lock. To release the lock in electromagnetic locking cylinders, the locking cam must be non-rotatably connected (i.e. coupled) with a handle, e.g. a knob. In an unreleased state, at least the handle arranged on the outside of the door is not non-rotatably connected with the locking cam (un-coupled state). For switching between the coupled and the uncoupled locking cam, a clutch (also inter-changeably referred to herein as a switchable clutch) is required. Such clutch, being switchable by the lock control, has on the one hand to be so small that it can be integrated into a locking cylinder, and on the other hand has to absorb comparatively high torques, such that even malfunctioning, e.g. sticking locks can be opened. The energy supply is mostly provided by batteries, which is why the energy requirement of the coupling for a closing and opening operation has to be minimized.
[0008] In DE 198 54 454 C2, an electromechanical locking cylinder with an external knob is described, which can be non-rotatably coupled with a locking cam via an electromotively actuated clutch. For this purpose, a shaft is guided from the outside knob into an inner knob, where it carries a support for a linear drive. By means of the linear drive, a coupling element may be inserted in a recess of the hollow shaft which is as well led out from the locking cylinder shaft. The end of the hollow shaft being led out is extended in a flange-like manner and carries the inner knob. The other end of the hollow shaft carries the locking cam.
[0009] DE 10 2004 056 989 A1 also describes a locking cylinder with a clutch for a non-rotatable connection of two knobs with a locking cam. The outer knob sits on a pin mounted in the locking cylinder, which pin is non-rotatably connected to a hollow shaft. A coupling gear sits non-rotatably on the hollow shaft. The coupling gear is located in the door-inner-side half of the locking cylinder and is overlapped by axially displaceable coupling claws. The coupling claws each have a radially inwardly facing locking protrusion at their distal end, which can be inserted between the teeth of the coupling gear. Thus, the claws can be non-rotatably coupled to the hollow shaft. When, in addition, the claws engage with counter-claws of a sleeve bearing the locking cam, the lock can be operated by turning the outer knob. The claws are located on an axially displaceable ring and extend from the ring towards the outside of the door. In addition, the ring is permanently non-rotatably connected to a flange bearing the inner knob. By correspondingly displacing the ring, the claws can be disengaged from the counter-claws, whereby the inner knob is decoupled from the locking cam.
[0010] U.S. Pat. No. 6,460,903 B1 discloses a door lock with an inner knob and an outer knob acting on a door latch. The inner knob is permanently connected to the door latch via an output shaft, such that said door latch can be permanently retracted by a rotation of the inner knob at any time. The outside knob has a ring being non-rotatably connected to the corresponding handle with a spur toothing in which a coupling ring can be inserted by means of a slider. The coupling ring has two radially placed entraining wing parts, each having two teeth being complementary to the spur toothing. The entraining wing parts are mounted axially displaceable in two slots of a connecting element, such that a rotation of the coupling ring is transmitted to the connecting element. The connecting element has a receiving area in which the output shaft is mounted non-rotatably.
[0011] U.S. Pat. No. 6,460,903 B1 also describes an electronic door lock with two knobs that act on a door latch. The inner knob permanently acts on the latch, the outer knob can be indirectly coupled to an output shaft of the inner knob.
[0012] In WO 2011/119097 A1, a window handle with locking being adjustable by an electromotor is disclosed. Balls can be inserted by an axial slider in a radial direction in corresponding receiving areas of a rosette screwed to the window, thereby causing the window handle to be locked against rotation.
[0013] Alternatively, also clutches are known which are arranged under a cover being arranged directly on the door leaf and serving to connect a doorknob with a nut of a mortise lock (EP 1 662 076 B1, EP 1881135 A1, EP 1522659 B, DE 10 2009 018471 A). These find, however, only limited acceptance for aesthetic reasons.
SUMMARY
[0014] The object of the present invention is to simplify the—often perceived as cumbersome—release of the lock by means of a locking cylinder.
[0015] A door handle, also called doorknob, is a lever-like device for opening and closing the latch of a door. The door handle thereby acts via a shaft, usually a square shaft, on the so-called spindle hole (referred to, shortly, as a nut) of a mortise lock (see e.g. DIN 18 251). A door handle usually has two legs: a first leg the longitudinal axis of which generally, or even preferably, coincides with the rotation axis of the nut, and a second leg attached angled thereto and acting as a lever. For actuating the door handle, the second leg is pivoted about the longitudinal axis of the first leg, rotating the first leg accordingly. Usually, the first leg is much shorter than the second leg.
[0016] The door handle has a door-side output shaft and a handle facing away from the door. The output shaft may be, as usual, connected to the nut of a mortise lock via e.g. a square shaft. The handle serves to pivot the door handle about an axis of rotation. The handle serves to pivot the door handle about a rotation axis. The handle and the output shaft have a common rotation axis and are connected to one another via a preferably electro-mechanical clutch.
[0017] A shifting clutch (also referred to herein as a clutch) is to be understood as a coupling which can be opened and closed. In an open state of the clutch, the handle is freely rotatable with respect to the output shaft, i.e. the door cannot be opened. In a closed state of the shifting clutch, the handle and the output shaft are non-rotatably connected to each other, so the door can be opened. The adjustment of the shifting clutch between the two states “closed” and “open” is preferably carried out electromechanically, so that a lock control can switch the clutch between the two states.
[0018] Preferably, the output shaft has a recess on the side facing towards the handle, in which a coupling element is mounted preferably axially displaceable. The handle has a receiving area for receiving the coupling element, which receiving area is located preferably directly opposite to the recess. The recess, the coupling element and the receiving area are complementary to each other and are not rotationally symmetric to the rotational axis in at least one section, so that a rotation movement is transmitted from the handle to the output shaft via the coupling element, when the coupling element (more precisely, the at least one non-rotationally symmetrical section of it) engages in the complementary sections of both the recess and the receiving area. If the coupling element rotationally engages into the recess and the receiving area, the clutch is locked, and correspondingly the coupling element is in the closed-position. When the coupling element rotationally engages only in one of the receiving area and in the recess, the clutch is opened and the coupling element is in the open-position. Generally, the receiving area is also a recess of the handle. Merely for linguistic distinction between the two recesses, the term ‘receiving area’ is used. One could alternatively speak of a first recess (the recess) and a second recess (the receiving area).
[0019] A linear drive is arranged in the handle, which drive acts on the coupling element to displace the coupling element in axial direction out of the recess so far that, it engages both in the recess and in the receiving area in order to thereby close the coupling. For opening of the coupling, the coupling element is displaced from the receiving area back into the recess. Such a clutch is very reliable, compact and can transmit also high torques with only little material. In addition, this clutch can be arranged in a very narrow shaft, i.e. in a narrow door-side leg of a door handle. The door handle can therefore be correspondingly slim and does not necessarily differ visually from the usual rigid door handles that do not contain a clutch.
[0020] Preferably, the recess receives the coupling element completely if it is in its open position. In the closed-position of the coupling element, it is arranged preferably completely in a cavity formed by the recess and the receiving area. This allows to form the clutch particularly compact. In addition, the end faces of the output shaft and the handle preferably abut each other (thereby forming a rotation gap or a plain bearing), whereby tilting moments are introduced from the handle into the output shaft, which increases the stability of the door handle.
[0021] Preferably, the output shaft is rotatably mounted in a door-side recess of the handle. This can ensure that a displacement of the coupling element is not disturbed by forces acting on the handle in a direction radial with respect to the rotation axis. For absorbing such forces, the handle is preferably rotatably mounted relative to the door leaf. For this purpose, e.g. a rosette overlapping the door-side end of the handle can be formed as a bearing for the handle. Such rosette can also be fastened (e.g. by screws) to the door leaf from the inside of the door, and can thereby complicate an attack on the clutch of the door handle mounted on the outside. With regard to an adjustment of the clutch, the rosette preferably has no function, in this regard of the door handle is autonomous.
[0022] Preferably, the coupling element is pre-loaded or biased in the direction of the handle. For closing the door, it is then sufficient to release the way of the coupling element in the direction of receiving area. Once the output shaft and the handle are correspondingly aligned to each other, the coupling element is displaced such that it engages in the receiving area and in the recess. The clutch is now closed. For opening of the shifting clutch, the coupling element is moved out of the receiving area, whereby the pre-load (a bias) is increased again. For biasing, a biasing spring, e.g. a coil spring, may be arranged between the bottom of the recess and the coupling element. Preferably, a rosette for mounting on a door leaf overlaps the handle and is so connected with the handle via a return spring, such that the handle is biased against a stop toward its closed-position. Thereby, the handle is in a well-defined, e.g. usually horizontal position also with an open clutch.
[0023] Preferably, the handle has a door-side hollow shaft (a hollow shaft on a door-side of the handle), in which the output shaft and at least a part of the linear drive are disposed. Thereby, the handle protects the output shaft from unauthorized access and enables a particularly compact design. More preferably, the output shaft is rotatably mounted in the hollow shaft. When closing the switching clutch, the rotation is of course blocked or at least restricted.
[0024] For example, the handle may have a handpiece that is non-rotatably connected with the hollow shaft with two legs being arranged angled (that is, at an angle with respect) to each other. The door handle then has the form of a conventional door lever. For mounting, it is advantageous if the handpiece comprises at least two half-shells, between which at least one fixing portion of the hollow shaft is arranged. For example, the half-shells may have a door-side external thread, on which a union nut is seated, which fixes the half-shells on the hollow shaft. The union nut should preferably be protected against unauthorized opening, e.g. be overlapped by a rosette or be locked by a stop only being reachable after dismounting the door handle.
[0025] In the leg facing away from the door (i.e. in the leg of the handle being at least approximately parallel to the door leaf), a battery for energy supply of the door handle may be provided. For example, the ends of the half-shells facing away from the door may open into a hollow profile, which holds together their ends and e.g. provides space for at least one battery or for at least parts of a circuitry, such as a lock control.
[0026] The linear drive preferably has at least one control member that is axially displaceable and rotatably mounted in the handle, which engages in the coupling element in such a way that a displacement of the control member results in a displacement of the coupling element. Accordingly, the control member has at least one “open-position” in which the clutch is open and one “closed-position” in which the clutch is closed.
[0027] The control member preferably has at least one (e.g. slotted) thread, into which a pin or a complementary threaded portion engages, which is rigidly connected to the handle. Alternatively, the control member can also have only one thread-like contact surface for the pin or the threaded section, in which case the control member and/or the pin or threaded section, respectively, are mutually spring-loaded. Thereby, a rotational movement of the control member can be converted into a linear movement, i.e. a rotation of the control member also causes a linear movement, preferably axially to the rotation axis.
[0028] The drive of the control member may e.g. be carried out by a motor controlled by a lock control. The motor may preferably be arranged in the handle and may drive a drive wheel for the control member, at least indirectly. The drive wheel may preferably be arranged coaxially to the rotation axis of the control member. The drive wheel is connected to the control member in order to entrain it with a rotational movement. Preferably, the control member and the drive wheel are connected via a spring element, e.g. a coil spring. The spring element compensates on the one hand the changes in distance between the adjusting element and the drive wheel during axial displacement of the adjusting element, and in addition serves as energy storage, when the adjusting element is blocked. If for example the control member is to be moved in the direction of the output shaft, it may occur that the coupling element, e.g. by actuating the handle, is stressed such that it jams. Accordingly, a movement of the control member in the direction of the coupling element is not possible. The motor can be controlled by the lock control, regardless of this circumstance. Thereby, it drives the drive wheel and loads the spring element in the corresponding direction of rotation. Once the coupling element is relieved, i.e. no longer jammed, the blockage of the control member is also relieved. The energy stored in the spring element is converted into a displacement of the control member, and thereby also the coupling element is displaced correspondingly.
[0029] Preferably, the drive wheel is partially toothed, i.e. it has a toothed region and in the extension of the toothed region as well a non-toothed region, wherein the angular range being spanned by the toothed region corresponds to the rotation angle of the drive wheel, which rotation angle is necessary to adjust the control member between its “open-position” (in which the clutch is open) and its “closed-position” (in which the clutch is closed).
[0030] In the handle, particularly in a cavity between at least two half-shells of the handle, electrical components, e.g. a lock control or a part thereof may be arranged. The lock control is adapted to exchange data with an electronic key, (e.g. an RFID transponder) via a data link (e.g. a radio data link). Based on the data, the lock control checks the locking authorization of the key and drives the linear drive, if the locking authorization does not correspond with the state of the clutch, i.e. for a given locking authorization the clutch is closed and is otherwise opened, if necessary.
[0031] Herein the term ‘non-rotatably connected’ is used to express that two pieces are connected such that a transmission of torque from one piece to the other is (and vice versa) is possible. For example, when clutch having an input shaft and an output shaft is closed, the input shaft and the output shaft of the clutch are ‘non-rotatably connected’. In case the clutch is open, they are ‘ rotatably connected’.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] In the following, the invention will be described by way of example, without limitation of the general inventive concept, on examples of embodiment and with reference to the drawings.
[0033] FIG. 1 a shows a perspective view of a door handle.
[0034] FIG. 1 b shows the door handle of FIG. 1 a in the front view.
[0035] FIG. 2 a shows a longitudinal section of the door handle along the plane A-A.
[0036] FIG. 2 b shows a detail of FIG. 2 a.
[0037] FIG. 3 a shows a longitudinal section of the door handle along the plane B-B.
[0038] FIG. 3 b shows a detail of FIG. 3 a.
[0039] While the invention can be modified without changing its scope and take 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 spirit and scope of the present invention as defined by the appended claims.
DETAILED DESCRIPTION
[0040] FIG. 1 shows a door handle 1 , here in the form of a door lever. The door handle 1 has a handle 10 being pivotable about a rotation axis 2 , with a door-side first leg 11 , the longitudinal axis 2 of which is oriented in approximately orthogonal direction with respect to a door leaf (when mounted on the door), and with a second leg 12 angled with respect to the first leg. The region in which the first and second legs meet at an angle consists of two half-shells 13 , 14 being held together by a nut 15 on the door side and a sleeve 16 on the other side. As indicated, the handle 1 may have a receiving area for a square shaft 17 , to non-rotatably couple the door handle with the nut of a mortise lock. A rosette 18 may be provided to fasten and mounting the door handle 1 to a door leaf and protect the clutch (which will be described in more detail below) against manipulation. An output shaft 30 (cf. FIGS. 2 a to 3 b ) is covered by the handle 10 , which output shaft 30 acts on the (illustrated as) square shaft 17 , i.e. it is connected with the square shaft 17 in a manner permitting transmission of a rotational movement. To be more precise, the rotational movements about the longitudinal axis 2 are transmitted. In contrast thereto, tilting moments applied orthogonally to the longitudinal axis 2 are preferably at least substantially absorbed from the bearing of the handle 10 by the rosette 18 , and are introduced into the door leaf. A clutch is located between the handle 10 and the output shaft 30 , in order to non-rotatably connect the handle 10 with the output shaft 17 by means of a lock control (clutch closed) or in order to uncouple both (clutch open). Preferably, the handle 10 rests on the rosette 18 via a return spring 19 , thus, the door handle does not hang down when the clutch is open. The rosette 18 may preferably be fastened to the door leaf from the inner side of the door, or may be fixed otherwise with same.
[0041] The functioning of the door handle is explained by way of the two sections A-A and B-B, i.e. of FIGS. 2 a to 3 b : The door handle 1 has an output shaft 30 on the door side, which is rotatably mounted in a hollow shaft 50 of the handle 10 . The output shaft 30 and the hollow shaft 50 have a common rotational axis 2 and may be non-rotatably coupled to each other via the clutch (or decoupled, if the clutch is open). The output shaft 30 is non-rotatably connected with the square shaft 17 , as illustrated. The hollow shaft 50 is non-rotatably connected with the handle 10 . In the example shown, the hollow shaft 50 has an attachment portion 52 by which it is fixed between the two half-shells 13 , 14 .
[0042] The output shaft 30 has a recess 31 on its side facing towards the hollow shaft 50 . In the recess 31 sits a coupling element 40 . The coupling element 40 is axially displaceable but not freely rotatable. The coupling element 40 is for example (circularly-)cylindrical and has a cam 401 on at least one side (two cams 401 are shown) which engages (engage) in a (each) complementary groove of the recess 31 . Alternatively, the coupling element 40 may have at least one flattened portion which interacts with a complementary flattened portion of the hollow shaft 50 and the output shaft 30 . It is only important that the coupling element 40 may (depend-ent on its position) generate a torque-transmitting form-fit connection with the hollow shaft 50 and/or with the output shaft 30 . The cylindrical part of the coupling element 40 is arranged coaxially with the rotation axis.
[0043] The hollow shaft 50 has a receiving area 51 opposite to the recess 30 . The receiving area 51 is also complementary to the form of the coupling element 40 . If the coupling element 40 is displaced into the receiving area 51 in axial direction to an extend that the coupling element 30 engages both in the recess 31 and in the receiving area 51 , the hollow shaft 50 and thus the handle 10 are non-rotatably connected with the output shaft 30 , i.e. the clutch is closed. Therefore, the output shaft 30 is taken upon actuation of the handle, and the rotation movement is transmitted to the square shaft 17 . In other words, the rotation of the handle is transmitted via the clutch to the output shaft.
[0044] When the coupling element 40 as shown is pushed back into the recess 31 of the output shaft 30 so far that it no longer engages with the receiving area 51 of the hollow shaft, the clutch is open. In the open state of the clutch, upon actuation of the door handle, the rotation is not transmitted to the output shaft 30 .
[0045] The adjustment of the coupling element 40 is preferably carried out by means of a control member 41 . The example of shown control member 41 is rotatably mounted and axially displaceable the hollow shaft 50 on a rod 54 . The control member 41 has a thread-shaped slot 42 (more generally: a thread 42 ) into which a pin 53 engages radially as a complementary threaded section, said threaded section 53 is connected at least substantially rigid to the handle 10 via rod 54 . In the example shown, the rod 54 is held by a gear block 61 ; other fastenings are also possible. It is only important that the rod 54 and the control member 41 can be rotated relative to each other about the longitudinal axis 2 . Upon rotation of the control member 41 about its longitudinal axis 2 , said control member is either pushed forward in the direction towards the output shaft 30 according to the rotational direction, by interaction of the threaded section 53 and the thread 42 , or is pushed back in the opposite direction. If the control member 41 is pushed forward, it pushes the coupling element 40 against the force of a spring 32 (which spring rests against the bottom of the recess 31 ) so far into the recess 30 , that the coupling element 40 is not engaged with the receiving area 51 ; the clutch is now open. The control member has reached one of its two end positions, namely its “open end position”. If the control member 41 is rotated back and thereby retracted, the coupling element 40 follows the control member 41 into the receiving area 51 of the hollow shaft 50 due to the spring 32 , wherein the spring 32 is at least somewhat relaxed; the clutch is closed. The control member 41 now has reached the other end position, the so-called “closed end position”.
[0046] To displace the control member 41 axially, it is rotatably driven about its longitudinal axis 2 . For this purpose, a motor 45 driven by a lock control (not shown) drives a drive wheel 44 via a preferably self-locking gear, the drive wheel 44 being arranged preferably coaxially with regard to the control member 41 . The drive wheel 44 thereby entrains a first end of a spring element 43 (at least indirectly). The other, second end of the spring element 43 is (at least indirectly) attached to the control member 41 such that upon rotation of the drive wheel 44 the control member 41 is rotated, provided that the coupling element is not blocked. Therewith, the adjusting element 41 and thus also the coupling element 40 are axially displaced due to the threaded section 53 engaging axially into the thread. If, however, the control member is axially blocked, the spring element 43 is loaded by the rotation of the both ends against each other. Once the blockage is relieved, the control member 41 follows the rotation of the drive wheel 44 , wherein the spring element is relaxed again.
[0047] If the drive wheel 44 is driven to open the clutch, i.e. to push forward the control member 41 , it may occur that at the same time the handle 10 is actuated. In this case, the coupling element 40 is clamped between the output shaft 30 and the hollow shaft 50 and thereby blocks an axial displacement of the control member 41 . The coupling element is jammed. Therefore, only the spring element 43 is tensioned by the rotation of the drive wheel 44 , i.e. kinetic energy is stored as potential energy in the spring element 43 . If the handle 10 is released, the clamping of the coupling element 40 is relieved, i.e. the control member 41 being pre-loaded by the spring element 43 can push the coupling element 40 out of the receiving area 51 and thus into the “open-position”.
[0048] Likewise, it may occur that the clutch is open when the door handle is actuated. In this case, the receiving area 51 of the hollow shaft 50 , i.e. of the handle is rotated against the recess 31 of the output shaft 30 , and the coupling element 40 cannot engage with the receiving area 51 even if the control member 41 is retracted. The coupling element 40 is not able to follow the control member 41 , despite the biasing of the bias spring 32 . Once the door handle is released, the grooves of the recess 31 and the receiving area 51 align, such that the coupling element 40 engages in the receiving area 51 of the hollow shaft 50 , thereby closing the clutch.
[0049] Preferably, the drive wheel 44 is a partly toothed gear, i.e. the drive wheel has at least a first toothed region and a second non-toothed region, wherein the non-toothed region is disposed in the imaginary extension of the toothed region. For adjusting the first end of the spring element 43 being at least indirectly entrained by the drive wheel, an output element (e.g. a screw (see FIG. 2 a ), a gear rack, or other gear) being driven by motor 45 engages in the toothed region of the drive wheel 44 . The toothed region is arranged on the drive wheel in a manner that the toothing no longer engages in the output element, as soon as the first end of the spring element 43 has reached one of its two end positions. In the first end position, the control member is spring-loaded in the direction of its “closed end position” and in the other end position it is spring-loaded towards its “open end position”. To adjust the control member 41 between its respective end positions, it is sufficient to drive the motor for a sufficiently long time period with the corresponding rotation direction. Once the entrained end of the spring element 43 has reached its desired end position, the output element and the drive wheel 44 disengage. Thus, the motor 45 can be operated time-controlled, and sensors for detecting an end position of the first end of the spring element are not necessary. It is sufficient to determine the time constant for controlling the motor to be big enough. If the desired end position of the entrained first end of the spring element 43 has been reached and the drive wheel 44 and the driven element are not engaged with each other, the control member is now spring-loaded in the direction of its respective end position and the “last tooth” of the toothed region is correspondingly pushed against the complementary toothing of the output element by the spring element 43 . If the control member 41 is to be shifted into the other end position, it suffices to drive the motor 45 again for a sufficiently long time period, but with the reverse direction. Again, the teeth engage in one another until the entrained end of the spring element 43 has reached its second end position. Now, the control member is spring-loaded in the direction of its corresponding (different) end position, and due to the spring-load, the “first tooth” of the toothed region fits closely to the complementary toothing of the output element. Therefore, the drive wheel 44 would again be entrained by the output element with a repeated reversal of rotation direction of the motor 45 .
[0050] The door handle has been described by way of an example, in which in mortise of an open clutch the coupling element is seated in the output shaft and the linear drive is integrated in the handle. This the output shaft to be kept relatively short, which makes an attack difficult. In principle, the clutch can be rotated by 180°. Then the coupling element 40 would sit in the handle in case of the open position. Independently of this, the linear drive may be arranged in the handle, or in or at the output shaft. An essential advantage of the invention is that the rosette does not accommodates any elements being necessary for switching of the clutch. Further it should be noted, that door handle can as well have the form of a door knob. In this case the second leg is omitted and the first leg is thickened to thereby provide a handle.
[0051] It will be appreciated to those skilled in the art having the benefit of this disclosure that this invention is believed to provide a door handle. Further modifications and alternative embodiments of various aspects of the invention will be apparent to those skilled in the art in view of this description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the general manner of carrying out the invention. It is to be understood that the forms of the invention shown and described herein are to be taken as the presently preferred embodiments. Elements and materials may be substituted for those illustrated and described herein, parts and processes may be reversed, and certain features of the invention may be utilized independently, all as would be apparent to one skilled in the art after having the benefit of this description of the invention. Changes may be made in the elements described herein without departing from the spirit and scope of the invention as described in the following claims.
LIST OF REFERENCE NUMERALS
[0000]
2 rotation axis/longitudinal axis
10 handle
11 first leg
12 second leg
13 upper half-shell
14 lower half-shell
15 union nut
16 sleeve
17 square shaft
18 rosette
19 return spring
30 output shaft
31 recess of the output shaft
32 bias spring
40 coupling element
401 cam
41 control member
42 slot/thread
43 spring element, e.g. coil spring
44 drive wheel
45 motor
50 hollow shaft
51 receiving area
52 attachment portion
53 pin/threaded section
54 rod
61 block gear
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A door handle with a door-side output shaft 17 and a handle 10 facing away from the door, said output shaft and handle having a common rotational axis 2 and being connected via an electromechanical clutch, may be particularly compact and may have a particularly low energy intake for shifting the clutch by providing the output shaft 30 with a recess 31 on the side facing towards the handle 10 , in which a coupling element 40 is displaceably mounted; by providing the door handle 1 with a receiving area 51 for the coupling element 40 opposite to the recess; and by arranging a linear drive in the handle, the linear drive acting on the coupling element 40 in order to move the coupling element 40 in the axial direction so far out of the recess that the coupling element engages both into the recess 31 as well as into the receiving area 51 in order to close the clutch, and the coupling element is moved out of the receiving area 51 back into the recess 31 in order to open the clutch.
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FIELD OF THE INVENTION
The present invention generally relates to computers, in particular, to computer systems with a storage housing for its keyboard.
BACKGROUND OF THE INVENTION
The computer has become an indispensable electronic machine for the industrialized world. In particular, computers are used by businesses and households for numerous automated tasks and other complex functions. The advent of the Internet and the World Wide Web are creating new opportunities for consumers and businesses to exploit information technology, such as electronic commerce, on-line bill paying, web surfing, web-based information services, and other services.
As computers are becoming one of the most important electronic appliances in society, they will be placed in various physical locations in offices or homes. In homes and offices there is usually a limited amount of desktop or countertop space. Home users may want to locate the computer on a kitchen countertop surface for use in finding recipes on the Internet or using the computer as a viewing device for television. These uses require space in terms of volume and surface area to setup the computer.
In general, computers systems, such as personal computers, are frequently supplied in desktop models with a separate keyboard. For example, a home user purchasing a computer receives a separate computer housing unit, a video display unit or monitor (which may or may not be integrated with the housing unit), a keyboard, a mouse, and a number of peripherals. The consumer must then find a flat surface on which to set or place the personal computer or the consumer purchases a desk dedicated for the computer. Extra desktop surface area is needed to place the keyboard and the keyboard increases the clutter in the area. In the example of the kitchen, preserving surface area is important so the home user can perform other tasks in the kitchen.
Exposed keyboards have problems for many users. The keyboard may be dislodged from the resting surface and be damaged. There are problems of liquids or drinks being spilled into the keyboard. With computer systems being place in more nontraditional locations, there is an increased potential for damage to keyboards. Also, conventional personal computers having exposed keyboard are susceptible to key failures. Since the exposed keyboard is unprotected, overtime air-borne dust particles may become lodged between the physical keys of the keyboard. This dust may cause contact problems in the keys and micro-switches that operate with the keys. While a keyboard may be attached to a sliding tray positioned below a desktop such that the user manually pulls out the keyboard for use, such mounting is feasible only in limited applications. Thus what is needed a device that preserves worktop surface space and reduces the potential for damage to a keyboard of a computer.
SUMMARY OF THE INVENTION
The present invention is directed to a computer system having a keyboard, a keyboard storage portion and a carrier that overcomes the disadvantages in the prior art.
In one aspect of the present invention a computer system includes a processing unit, and a carrier that is movable relative to the processing unit. The carrier is sized for retaining a keyboard. A drive mechanism capable of moving the carrier in different directions.
In another aspect of the present invention the computer system includes a processing unit housing, in which the housing includes a keyboard storage portion. The keyboard storage portion is at least partially located within the housing. Also included is a movable carrier sized for retaining a keyboard thereon. The carrier has a first position at least partially disposed within the keyboard storage portion and a second position at least partially disposed outside of the keyboard storage portion.
In yet another aspect of the present invention the computer system includes a keyboard having a battery connected to a charging connector. Also included is a carrier sized for retaining the keyboard. The carrier has at least a portion of a battery charger for charging the battery of the keyboard.
In another aspect of the present invention, the computer system includes a processing unit, and a keyboard having a transmitter for transmitting a signal. Further included is a carrier that is sized to retain the keyboard. The carrier has a receiver for receiving the keyboard signal. The carrier is operatively coupled to the processing unit for processing the signal.
Another aspect of the present invention, includes a method of moving a keyboard for the computer system having a movable carrier sized to retain the keyboard, and a drive mechanism coupled to the carrier. The method includes providing a control signal to the drive mechanism, and moving the carrier by the drive mechanism. Another aspect of the present invention includes a method of charging a keyboard for a computer system including a carrier having a portion of a battery charger. The method includes connecting the keyboard to a portion of the battery charger. And disconnecting the keyboard from the portion of the battery charger.
Yet another aspect of the present invention includes a method of wireless communication in a computer system. A keyboard has a wireless transmitter. A movable carrier retains the keyboard. The method includes transmitting a signal from the transmitter. The signal is received by the carrier having a receiver mounted on it. The signal is processed by the computer system.
These and other aspects of the present invention will be apparent upon consideration of the following detailed description thereof, presented in connection with the following drawings in which like reference numerals identifying the elements throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of one example of a computer system according to the present invention;
FIG. 2 is an isometric view of the front right side of a computer system;
FIG. 3 is an isometric view of the front left side of the computer system;
FIG. 4 is a front elevational view of the computer system;
FIG. 5 is a right side elevational view of the computer system;
FIG. 6 is a schematic plan view of an embodiment of a drive mechanism and a carrier providing linear motion;
FIG. 7 is an isometric view of the carrier;
FIG. 8 is a partial view of a side of the keyboard and a lateral side of the carrier;
FIG. 9 is a schematic block diagram of one embodiment of a drive mechanism;
FIG. 10 is schematic block diagram of another embodiment of the drive mechanism;
FIG. 11 is a flow diagram showing an operation sequence of the computer system of the present invention;
FIG. 12 is a schematic diagram of an embodiment of the keyboard and the carrier in a hard-wired signaling arrangement;
FIG. 13 is a schematic diagram of an embodiment of the keyboard and the carrier in a wireless signaling arrangement;
FIG. 14 is a schematic diagram of an embodiment of the keyboard and carrier in an induced current charging arrangement;
FIG. 15 is a schematic diagram of an embodiment of the keyboard and carrier in a contact battery charging arrangement; and
FIG. 16 is a side elevational view of an alternative embodiment of the carrier.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1-16 illustrates a computer system according to the present invention designated generally by reference numeral 100 . The computer system 100 may be a personal computer 200 , such as shown in FIG. 1, and may further include a keyboard 201 , and a carrier 160 connected to a drive mechanism 180 and a drive control system 177 .
FIG. 1 is a schematic diagram of one example of a computing environment in which the computer system 100 of present invention may be implemented. The present invention may be implemented within a general purpose computing device in the form of a conventional personal computer 200 , including a processing unit 210 , a system memory 220 , and a system bus 230 that couples various system components including the system memory to the processing unit 210 . The system bus 230 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 bus architectures. The system memory includes read only memory (“ROM”) 240 and random access memory (RAM) 250 .
A basic input/output system 260 (“BIOS”), containing the basic routines that help to transfer information between elements within the personal computer 200 , such as during start-up, is stored in ROM 240 . The personal computer 200 further includes a hard disk drive 270 for reading from and writing to a hard disk, not shown, a magnetic disk drive 280 for reading from or writing to a removable magnetic disk 290 , and an optical disk drive 291 for reading from or writing to a removable optical disk 292 such as a CD ROM or other optical media. The hard disk drive 270 , magnetic disk drive 280 , and optical disk drive 291 are connected to the system bus 230 by a hard disk drive interface 292 , a magnetic disk drive interface 293 , and an optical disk drive interface 294 , respectively. The drives and their associated computer-readable media provide nonvolatile storage of computer readable instructions, data structures, program modules and other data for the personal computer 200 .
Although the exemplary environment described herein employs a hard disk, a removable magnetic disk 290 and a removable optical disk 292 , it should be appreciated by those skilled in the art that other types of computer readable media which can store data that is accessible by a computer, such as magnetic cassettes, flash memory cards, digital video disks, Bernoulli cartridges, zip drives, random access memories (“RAMs”), read only memories (“ROMs”), and the like, may also be used in the exemplary operating environment.
A number of program modules may be stored on the hard disk, magnetic disk 290 , optical disk 292 , ROM 240 or RAM 250 , including an operating system 295 , one or more application programs 296 , other program modules 297 , and program data 298 . A user may enter commands and information into the personal computer 200 through input devices such as a keyboard 201 and pointing device 202 . The pointing device 202 may be a device, or a mouse. Other input devices (not shown) may include a microphone, joystick, game pad, satellite dish, scanner, or the like. These and other input devices are often connected to the processing unit 210 through a serial port interface 206 that is coupled to the system bus, but may be connected by other interfaces, such as a parallel port, game port or a universal serial bus (“USB”). A monitor 207 or other type of display device, such as a liquid crystal display (“LCD”) is also connected to the system bus 230 via an interface, such as a video adapter 208 . In addition to the monitor, personal computers typically include other peripheral output devices (not shown), such as speakers and printers.
The personal computer 200 may operate in a networked environment using logical connections to one or more remote computers, such as a remote computer 209 . The remote computer 209 may be another personal computer, a server, a router, a network PC, a peer device or other common network node, and typically includes many or all of the elements described above relative to the personal computer 200 , although only a memory storage device 211 has been illustrated in FIG. 5 . The logical connections depicted in FIG. 5 include a local area network (“LAN”) 212 and a wide area network (“WAN”) 213 . Such networking environments are commonplace in offices, enterprise-wide computer networks, intranets, the Internet and the World Wide Web.
When used in a LAN networking environment, the personal computer 200 is connected to the local network 212 through a network interface or adapter 214 . When used in a WAN networking environment, the personal computer 200 typically includes a modem 215 or other means for establishing a communications over the wide area network 213 , such as the Internet or the world wide web. The modem 215 , which may be internal or external, is connected to the system bus 230 via the serial port interface 206 . In a networked environment, program modules depicted relative to the personal computer 200 , or portions thereof, may be stored in the remote memory storage device. It will be appreciated that the network connections shown are exemplary and other means of establishing a communications link between the computers may be used.
For a brief overview of the operation of the present invention, FIG. 5 illustrates the computer system 100 in the preferred embodiment shown with the carrier 160 in a first position (as shown in the solid lines) and a second position (as shown in the broken lines). The carrier 160 retains or supports the keyboard 201 for movement thereof. As shown in the solid lines, the first position is defined when the carrier 160 is substantially located, or at least a portion of it is located in a keyboard storage portion 104 . As shown in the dotted or broken lines, the second position is defined when the carrier 160 is in position to allow the keyboard 201 to be accessible or exposed to the user. Note the second position may be an extended location in which the keyboard 201 is substantially outside of the keyboard storage portion 104 . The drive mechanism 180 moves the carrier 160 between the first position and the second position. In general, the carrier 160 may operate similar to a compact disk (“CD”) tray system found in the art.
Referring to FIGS. 2-5, the computer system 100 further includes a housing 102 , and the keyboard storage portion 104 . The housing 102 encloses and protects at least some of the internal components of the personal computer 200 . The housing unit 102 preferably houses the processing unit 210 . The housing 102 includes a top wall 116 , right side wall 118 , left side wall 120 , and a front wall 122 in which the walls 116 , 118 , 120 , 122 are interconnected. As shown in FIGS. 2, 3 , and 5 , the right and left side walls 118 and 120 may be stepped upwardly in the front so that a portion of the housing 102 is superimposed above the keyboard storage portion 104 . The housing 102 also includes a recess 127 which defines the keyboard storage portion 104 and the recess 127 is sized for the carrier 160 . The housing 102 also includes a rear internal wall 126 and a base 124 which forms the back and bottom boundaries of the recess 127 respectively. The base 124 forms the bottom of the housing 102 .
The keyboard storage portion 104 is disposed within the housing 102 to substantially enclose and retain the keyboard 201 . In the first position, the carrier 160 and the drive mechanism 180 are completely inside of the keyboard storage portion 104 . In one embodiment, the keyboard storage portion 104 may be opened at its left and right sides as shown in the figures. However, in an alternative embodiment (not shown), the left and right sides of the keyboard storage portion 104 may be sealed or covered as desired. While illustrated as being open in FIGS. 2-5, the front face of the keyboard storage portion 104 may be enclosed or covered with a flap that is pivotally disposed on housing 102 above the keyboard storage portion 104 or on the base 124 . The flap would be mounted and function similar to a coverflap on a video cassette recorder.
The computer system 100 further includes a support 110 for a monitor 207 that may be employed to fixedly attach the monitor 207 to the housing 102 ; a camera 134 ; a proximity sensor 136 ; and a power button 142 . The camera 134 is preferably a digital type that is connected to the serial port interface 206 or the universal serial bus (not shown). The camera 134 may be built into the monitor 207 or provided as a separate component. The proximity sensor 136 senses the presence of a user who sits in front of the computer system 100 . The proximity sensor 136 may be a built into the monitor 207 or provided as a separate component and may be a passive infrared type. The camera 134 may also be used with the software to function as a proximity sensor.
Referring to FIGS. 7 and 8, the carrier 160 is mounted for movement between the first position at least partially inside of the keyboard storage portion 104 , and the second position at least partially external to the keyboard storage portion 104 in which the user may access the keyboard 201 . In a preferred embodiment, the carrier 160 is slidably disposed on the base 124 within the keyboard storage portion 104 . However, the carrier 160 may be slidably disposed on the side wall portions of the housing 102 . The carrier 160 is sufficiently sized to receive the keyboard 201 thereon, and includes a receiving portion 162 for retaining the keyboard 201 therein. The receiving portion 162 preferably includes a substantially level surface 161 , on which the keyboard 201 rests. The surface 161 may include a friction increasing material such as a rubberized material to minimize the lateral movement of the keyboard 201 while in transport or in use. The receiving portion 162 further includes a plurality of lateral side ledges that retain the keyboard 201 during use and transport to maintain the relative position in the receiving portion 162 . The receiving portion 162 preferably includes a right ledge 164 , a left ledge 166 , and a rear ledge 168 . The ledges 164 , 166 , 168 substantially define the receiving portion 162 of the carrier 160 . Referring to FIG. 8, if desired, the right ledge 164 , left ledge 166 , and rear ledge 168 may provide complementary mating surfaces to the respective right, left and rear of the keyboard 201 . This complementary structure assists in maintaining the relative position of the keyboard 201 .
The carrier 160 and housing 102 may further include a structure to assist for movement of the carrier 160 . This may include an adaptation of any dependable linear guides such as used on a sliding drawer structure. In a preferred embodiment, a left track 170 and a right track 172 allow the carrier 160 to move relative to the base 124 and the housing 102 including the processing unit 210 . This movement is substantially linear in a reciprocal or back and forth manner. The left track 170 and a right track 172 are mounted on the bottom surface 174 underneath the carrier 160 . In one arrangement, the tracks 170 and 172 may embody linear guides mounted on the right ledge 162 and left ledge 164 . The tracks 170 and 172 may be movable in guides on the base 124 . As shown in FIG. 6, in another arrangement, the left track 170 or the right track 172 , or a separate structure, may include a plurality of gear teeth 176 that cooperates and engages with the drive mechanism 180 . The cooperative features of the drive mechanism 180 and carrier 160 will be explained below. It will be appreciated that the carrier 160 may be any surface for retaining the keyboard 201 and need not include ledges. Also the tracks 170 and 172 may be any type of device, similarly found on many drawers, that allows substantially linear movement of the carrier 160 , such as ball bearings, roller bearings, or rollers.
The drive mechanism 180 includes a number of different embodiments, for example, a gearing drive or a spring drive. The drive mechanism 180 provides power or motion to the carrier 160 in response to a control signal 400 from the computer system 100 . In one arrangement, the drive mechanism 180 may be in the form of a solenoid unit (not shown) or a solenoid activates a movable member.
Referring to FIG. 9, in one embodiment, the drive mechanism 180 includes a motor 182 , and a gear 184 . The motor 182 includes a shaft 192 that rotates about an axis in which the shaft 192 imparts rotary motion to the gear 184 . The gear 184 includes a plurality of teeth 186 that engages complementary gear teeth 176 of the carrier 160 . In one arrangement the gear 184 has a circular periphery and the shaft 192 is mounted at the center of the gear 184 . In yet another arrangement, the shaft 192 may include a worm gear 181 that engages the gear 184 . In the worm gear 181 arrangement, the shaft 192 rotates about its axis, and the shaft 192 is disposed at a tangential position on the periphery of the gear 184 . It can be appreciated that the gearing arrangement shown is exemplary in that the arrangement may include a plurality of gears of varying diameters to control speed or geometries for gear design. In addition, the gearing arrangement may include a complement of pulleys and gears to move the carrier 160 .
FIG. 10 illustrates another embodiment of the drive mechanism 180 that includes a spring 194 biased towards pushing the carrier 160 away from the rear wall 126 of the keyboard storage area 104 . The spring 194 is adapted to engage a rear surface of the carrier 160 . In the spring 194 arrangement, the drive mechanism 180 includes a latch 178 . The latch 178 may be electrical/mechanical device that retains the carrier 160 in the position enclosed within the keyboard storage portion 104 . The latch 178 prevents the spring 194 from releasing energy to push the carrier 160 in a forward direction. The latch 178 also prevents the carrier 160 from traveling inadvertently forward out of the keyboard storage portion 104 . Upon release of the latch 178 the carrier 160 is unlocked thereby allowing the spring 194 to create a pushing force sufficient to transport the carrier 160 to an extended position. The user merely pushes the carrier 160 back in place to reattach the carrier 160 to the latch 178 .
In the event the computer system 100 is unpowered or there is an inadvertent malfunction, an emergency bypass is provided. The emergency bypass is disposed proximate to the keyboard storage portion 104 to activate the latch 178 without the aid of the drive processing unit 196 . The emergency bypass may be in the form of a button or other device. One can appreciate, the spring 196 may be in many forms or shapes and may be a plurality of springs based on the designer choice.
In general, the drive control system 177 receives the control signal 400 and actuates the drive mechanism 180 thereby causing the carrier 160 to travel from an enclosed position within the keyboard storage portion 104 to an extended position. Likewise if desired, the control signal 400 will cause the drive mechanism 180 to reverse direction to retract the carrier 160 from the extended position to an enclosed position within the keyboard storage portion 104 . The drive control system 177 is operatively coupled to the processing unit 210 via an appropriate interface, such as the serial port interface 206 or specially designed interface connected to the system bus 230 . The control signal 400 may be electronic or mechanical if desired by the designer. In an electronic signal arrangement, the control signal 400 is generated from the computer system 100 . In a mechanical signal arrangement, the control signal 400 is generated by a button, dial, or switch that generates a physical force.
The control signal 400 is generated from the computer system 100 . The computer system 100 includes a software program for processing input data received from a control signal device 301 . The control signal device 301 may be of various forms, the device 301 may include a depressible button 140 , a software command, a proximity sensor 136 , the camera 134 , a virtual button on a touch sensitive screen (not shown), a depressible button on the input device 202 , a scanner (not shown) that could recognize a discriminate an imprint of a thumb or a retina, an audible or audio sensor (not shown) for recognizing a verbal command from a user or similar input methods and devices. The software program may be implemented in the operating system 295 , application programs 296 , or other program modules 297 depending on the designer's preference.
Referring to FIG. 9, the drive control system 177 may include a signal processing unit 188 , and a sensor 190 . The signal processing unit 188 receives the control signal 400 and instructs or switches the motor 182 to rotate the shaft 192 clockwise or counter clockwise. When the motor 182 rotates the shaft 192 clockwise, the carrier 160 travels in a linear direction away from the rear wall 126 of the keyboard storage portion 104 and towards an extended position. Likewise, when the shaft 192 rotates counter-clockwise, the carrier 160 travels rearward towards the rear wall 126 . The sensor 190 senses the position of the carrier 160 . In a preferred arrangement, the sensor 190 may determine when the carrier 160 is substantially within the keyboard storage portion 104 and also determines when the carrier 160 is in an extended position. The signal processing unit 188 may include circuitry connected to a microprocessor, an application specific processor, relays, and/or switches. If desired, the signal processing unit 188 may include interfacing software to process the control signal 400 and inputs from the sensor 190 and motor 182 .
The sensor 190 cooperates with the signal processing unit 188 and the motor 182 . Alternatives for the sensor 190 , includes a rotary encoder that generates pulses; or a timer device configured to advance the length of the carrier 160 . In the timer device arrangement, the motor 182 operates for a predetermined time period associated with the length of the carrier 160 . Optionally, the sensor 190 may determined the quantity or length of the carrier 160 exposed from the keyboard storage area 104 . This is useful for situations where the full keyboard 201 is not required or when only a pointing device 202 is needed be exposed for use.
Referring to FIG. 10, the drive control system 177 may alternatively include a drive processing unit 196 connected to the computer system 100 , and a position sensor 198 . The position sensor 198 indicates to the computer system 100 via the drive processing unit 196 that the carrier 160 in the enclosed position or has been released forward. The position sensor 198 may be in the form of a switch or a microswitch disposed in the base 124 ; a switch combined with the latch 178 disposed at the rear end or front end of the keyboard storage portion 104 ; or any other appropriate location within the keyboard storage portion 104 . In a preferred arrangement, the carrier 160 engages or depresses the switch or a microswitch to retain it in a normally closed position. When the carrier 160 moves forward, the switch is released and opens in which drive processing unit 196 senses the opened position. In this opened position, the drive processing unit 196 transmits a signal to the computer system 100 for processing. The drive processing unit 196 may include a relay, and a microprocessor with related circuitry. If desired, the drive processing unit 196 may include interfacing software to process the control signal 400 and input from the position sensor 198 .
FIG. 11, illustrates a schematic of the control flow of the present invention including the operation of the drive control system 177 . The control may begin with a detection of the carrier 160 in the first position at step S 400 . The control signal 400 , such as a keyboard request command, is made from any implemented control signal device 301 at step S 402 . Control proceeds to step S 404 where the carrier 160 is advanced forward, in a first direction (i.e. out of the keyboard storage portion 104 ) by the drive mechanism 180 . In a gearing arrangement for the drive mechanism 180 , a timer or encoder determines when the carrier 160 has reached the second position. At step S 406 the extended position is detected. The control is then transferred to step S 408 where the signal processing unit 188 waits to detect a retract signal. If a retract signal is detected control is transferred to step S 410 where the carrier 160 reverses direction to travels towards the keyboard storage portion 104 back to the first position. If at step S 400 is carrier 160 is not in the first position, control is transferred to step S 408 . It is fully appreciated that one skilled in the art could implement the present invention in various alternative steps. For example, there may steps to turn on indication lights of the carrier 160 position status.
The keyboard 201 may provide signals directly to the serial port interface 206 of the computer 200 or may do so via a component on the carrier 160 . FIG. 12, illustrates one signal relationship between the keyboard 2101 and the carrier 160 . In the FIG. 12, the keyboard 201 transmits data to the personal computer 200 via a wired or cabled connection through the carrier 160 . The keyboard 201 transmits data through its output 302 . The keyboard output 302 is attached to a keyboard cable or cord 304 that includes a connector 305 . The connector 305 is then removably mated with a complementary keyboard carrier connector 306 on the carrier 160 . The carrier connector 306 is configured to be attached to send data to an interface of personal computer 200 , such as the serial port interface 206 or a dedicated keyboard port (not shown). The keyboard cord 304 , connector 305 , and carrier connector 306 may be a conventional design and function. For instances, the connector 305 may be in the form of a DIN or a mini DIN connector; the keyboard carrier connector 306 may be a mating connector with the appropriate pin-out of DIN connectors. Also the carrier 160 may include a connection for a pointing input device, such as a mouse 202 . The point device arrangement, may include conventional connectors and functional interfaces, such as an RS-232 interface, a PS/2 interface (not shown), or a mini-DIN connector (not shown).
FIG. 13, illustrates an arrangement between the keyboard 201 and the carrier 160 where the keyboard 201 transmits data to the personal computer 200 via a wireless connection. The wireless connection arrangement provides the user additional freedom to use the keyboard 201 . The keyboard 201 includes a mobile power source 309 , such as a battery; an encoder/decoder processor 308 ; and a transmitter 310 . The carrier 160 includes a receiver 312 operatively coupled to the processing unit 210 by way of a connection an interface of the personal computer 200 , such as the serial interface port 206 or a dedicate port (not shown). The keyboard 201 will generate and transmit scan codes to the receiver 312 . The wireless connection may include infrared frequencies or radio-controlled frequencies. The infrared red wireless configuration may include the standard Infrared Data Association (“IrDA”) protocols for point-to-point communications or other infrared wireless device technology. The radio-controlled configuration may include a transmitter 310 and receiver 312 operating at 49 MHz, but other alternative frequencies may be implemented. Also the carrier 160 may include a wireless receiver to receive signals from a pointing input device, such as a mouse 202 with a transmitter (not shown). If desired, the receiver 312 on the carrier 160 may receive wireless data from the mouse 202 and keyboard 201 .
To make the keyboard 201 more mobile, it may also be battery powered, and the carrier 160 may be used to recharge the keyboard battery. FIG. 14, illustrates the carrier 160 including the keyboard 201 with an induced current charging arrangement. The keyboard 201 is configured for wireless operation and includes a mobile power source 309 , such as a battery; a transmitter; and a charging coil 314 and associated circuitry (not shown). The mobile power source 309 may include a rechargeable battery. The carrier 160 includes a complementary shaped power source, such as a carrier coil 322 . The carrier coil 322 is preferably attached to a power source and may be attached to a power receptacle on computer 200 . The charging coil 314 and carrier coil 322 are configured such that when the keyboard 201 is disposed on the carrier 160 there is an electrical coupling between the charging coil 314 and carrier coil 322 . The electrical coupling causes an induced current in the charging coil 314 for providing the induced current to the mobile power source 309 for charging. Because the keyboard 201 consumes low power, the mobile power source 309 will last extended periods of time. The keyboard 201 in the induced charging arrangement, is advantageous because the keyboard 201 will be retained in the carrier 160 for extended periods of time. This allows the keyboard 201 to be charged overnight or other times thus saving the user the cost of replacing conventional batteries. In this arrangement, the keyboard storage portion 104 proximate the rear wall 126 may include some minor shielding from stray magnetic flux potentially associated with the charging coil 314 and carrier coil 322 .
The keyboard 201 may be battery power and have a direct current charging arrangement with the carrier 160 . FIG. 15, illustrates the carrier 160 including the keyboard 201 in a direct charging contact arrangement. The keyboard 201 includes a mobile power source 309 , such as a battery; and a transmitter 310 . The mobile power source 309 may include a rechargeable battery. In this arrangement, the keyboard 201 includes a charging receiver 316 having a pinned connector adapted to engage and contact an interfitting connector of an electrical power source 318 on the carrier 160 . The power pin connector 318 is coupled to any power source as described with respect to the carrier 160 . The pinned connector is commonly implemented with charging mobile phone batteries or other well-known methods. The keyboard 201 also includes a charging controller 320 configured to monitor capacity of the mobile power source 309 . In this arrangement, electrical current is transferred from the electrical power source 318 to the charging receiver 316 by way of the physical metal-to-metal contact of the pinned connection. It is recognized other electrical sources may be used such as a step-down AC-to-DC charger or other methods such as a physical plug may be used to provide power to charge the mobile power source 309 . After the battery is charged, the keyboard is disconnected from the electrical power source 318 . Because the keyboard 201 will be in the carrier 160 for an extended period of time and provides a continuous charging when in the carrier 160 , the charging arrangement avoids the replacement of conventional batteries. Thus saving the user time and frustration of replacing conventional batteries and saving the cost of periodically replacing the conventional batteries.
FIG. 16 illustrates an alternative embodiment of the carrier mechanism 160 that allows for incline adjustability of the keyboard 201 . Carrier 160 in this embodiment includes a secondary carrier 161 , pivotal arms 163 , 163 ′, a motorized pivot 165 , 171 , a secondary pivot 167 , and a height adjuster 169 . The secondary carrier 161 is connected to the carrier 160 at motorized pivots 165 , 171 . The motorized pivots 165 , 171 are fixedly disposed in the linear direction of the carrier 160 and includes a motor (not shown) and associated gearing (not shown). In operation, the motor causes the pivotal arm 163 , 163 ′ to rotate clockwise in which the cooperation of the gearing of the motor and pivotal arm 163 , 163 ′ lifts the arm 163 , 163 ′ upward. In turn, the secondary carrier 161 rotates about the secondary pivot 167 and is simultaneously lifted upward. This action causes the secondary carrier 161 to be inclined relative to the carrier 160 . Optionally, the motorized pivots 165 , 171 may be manual in which the user moves the secondary carrier 161 into position. In this embodiment, the carrier 160 may include the drive mechanism 180 , a wireless or wired arrangement for receiving output of the keyboard 201 as described earlier according to the present invention. The secondary carrier 161 is sized to retain or support the keyboard 201 .
In lieu of the disclosure of computer system 100 being a personal computer 200 such as shown in FIG. 1, it is fully appreciated that one of ordinary skilled in the art could implement the present invention with other computer systems; for example a network computing system and separate terminals. In this alternative embodiment the moveable keyboard carrier 104 could be coupled to a terminal housing similar to that of computer housing 102 . Further, computer system 100 could be what is commonly known as a Internet appliance or network appliance. The computer system 100 primarily accesses the Internet and operates software off the Internet. Such an arrangement would also preferably include a processing unit, a video display, a screen, a housing, and a keyboard.
There are other advantages to the present invention besides providing protection of the keyboard 201 or preserving worktop space. It is advantageous to present the keyboard 201 to the user, when it is required by an application program 296 or when the user desires to have it exposed for use. For example, the keyboard 201 is not required for all software applications; home and business users may use a personal computer for Internet browsing or occasional data entry. In one application of the present invention, the computer system 100 presents the keyboard 201 for heavy data processing, such as word processing and electronic spreadsheet applications.
A further advantage of the present invention is use for an additional security measure. An exposed keyboard is a security risk that may allow unauthorized individuals to access the computer. Individuals may use the keyboard to enter passwords or other commands to electronically break into a computer. Enclosing the keyboard or making it inaccessible to unauthorized users provides additional security protection.
While these particular embodiments of the invention have been shown and described, it is recognized that various modifications thereof will occur to those skilled in the art. Therefore, the scope of the herein-described invention shall be limited solely by the claims appended hereto.
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A computer system has a keyboard storage portion and carrier. The computer system may be a personal computer capable of generating a control signal. A keyboard holding carrier slides in and out of a processing housing. This enables selective positioning of a keyboard within the processing housing. A drive mechanism imparts reciprocal movement to the carrier and a drive control system is responsive to the control signal from the personal computer. Also included is a sensor connected to the drive mechanism that determines a position of the carrier relative to the personal computer.
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FIELD OF THE INVENTION
The present invention relates to therapeutics for the prevention and treatment of inflammatory bowel disease, and in particular the prevention and treatment of inflammatory bowel disease in humans as well as other animals through the use of avian polyclonal antibody therapy.
BACKGROUND OF THE INVENTION
Inflammatory bowel diseases (IBD) are defined by chronic, relapsing intestinal inflammation of obscure origin. IBD refers to two distinct disorders, Crohn's disease and ulcerative colitis (IC). Both diseases appear to result from the unrestrained activation of an inflammatory response in the intestine. This inflammatory cascade is thought to be perpetuated through the actions of proinflammatory cytolines and selective activation of lymphocyte subsets. In patients with IBD, ulcers and inflammation of the inner lining of the intestines lead to symptoms of abdominal pain, diarrhea, and rectal bleeding. Ulcerative colitis occurs in the large intestine, while in Crohn's, the disease can involve the entire GI tract as well as the small and large intestines. For most patients, IBD is a chronic condition with symptoms lasting for months to years. It is most common in young adults, but can occur at any age. It is found worldwide, but is most common in industrialized countries such as the United States, England, and northern Europe. It is especially common in people of Jewish descent and has racial differences in incidence as well. The clinical symptoms of IBD are intermittent rectal bleeding, crampy abdominal pain, weight loss and diarrhea. Diagnosis of IBD is based on the clinical symptoms, the use of a barium enema, but direct visualization (sigmoidoscopy or colonoscopy) is the most accurate test. Protracted IBD is a risk factor for colon cancer, and treatment of IBD can involve medications and surgery.
Some patients with UC only have disease in the rectum (proctitis). Others with UC have disease limited the rectum and the adjacent left colon (proctosigmoiditis). Yet others have UC of the entire colon (universal IBD). Symptoms of UC are generally more severe with more extensive disease (larger portion of the colon involved with disease).
The prognosis for patients with disease limited to the rectum proctitis) or UC limited to the end of the left colon (proctosigmoiditis) is better then that of fall colon UC. Brief periodic treatments using oral medications or enemas may be sufficient. In those with more extensive disease, blood loss from the inflamed intestines can lead to anemia, and may require treatment with iron supplements or even blood transfusions. Rarely, the colon can acutely dilate to a large size when the inflammation becomes very severe. This condition is called toxic megacolon. Patients with toxic megacolon are extremely ill with fever, abdominal pain and distention, dehydration, and malnutrition. Unless the patient improves rapidly with medication, surgery is usually necessary to prevent colon rupture.
Crohn's disease can occur in all regions of the gastrointestinal tract. With this disease intestinal obstruction due to inflammation and fibrosis occurs in a large number of patients. Granulomas and fistula formation are frequent complications of Crohn's disease. Disease progression consequences include intravenous feeding, surgery and colostomy.
Colon cancer is a known complication of chronic IBD. It is increasingly common in those patients who have had extensive IBD over many years. The risk for cancer begins to rise significantly after eight to ten years of IBD.
IBD may be treated medicinally. The most commonly used medications to treat IBD are anti-inflammatory drugs such as the salicylates. The salicylate preparations have been effective in treating mild to moderate disease. They can also decrease the frequency of disease flares when the medications are taken on a prolonged basis. Examples of salicylates include sulfasalazine, olsalazine, and mesalamine. All of these medications are given orally in high doses for maximal therapeutic benefit. These medicines are not without side effects. Azulfidine can cause upset stomach when taken in high doses, and rare cases of mild kidney inflammation have been reported with some salicylate preparations.
Corticosteroids are more potent and faster-acting than salicylates in the treatment of IBD, but potentially serious side effects limit the use of corticosteroids to patients with more severe disease. Side effects of corticosteroids usually occur with long term use. They include thinning of the bone and skin, infections, diabetes, muscle wasting, rounding of faces, psychiatric disturbances, and, on rare occasions, destruction of hip joints.
In IBD patients that do not respond to salicylates or corticosteroids, medications that suppress the immune system are used. Examples of immunosuppressants include azathioprine and 6-mercaptopurine. Immunosuppressants used in this situation help to control IBD and allow gradual reduction or elimination of corticosteroids. However, immunosuppressants render the patient immuno-compromised and susceptible to many other diseases.
Clearly there is a great need for agents capable of preventing and treating IBD. It would be desirable if such agents could be administered in a cost-effective and timely fashion, with a minimum of adverse side effects.
DEFINITIONS
The phrase “symptoms of IBD” is herein defined to detected symptoms such as abdominal pain, diarrhea, rectal bleeding, weight loss, fever, loss of appetite, and other more serious complications, such as dehydration, anemia and malnutrition. A number of such symptoms are subject to quantitative analysis (e.g., weight loss, fever, anemia, etc.). Some symptoms are readily determined from a blood test (e.g. anemia) or a test that detects the presence of blood (e.g., rectal bleeding). The phrase “wherein said symptoms are reduced” refers to a qualitative or quantitative reduction in detectable symptoms, including but not limited to a detectable impact on the rate of recovery from disease (e.g., rate of weight gain).
The phrase “at risk for IBD” is herein defined as encompassing the segment of the world population that has an increased risk for IBD. IBD is most commonly found in young adults, but can occur at any age. It occurs worldwide, but is most common in the United States, England, and northern Europe. It is especially common in people of Jewish descent. An increased frequency of this condition has been recently observed in developing nations.
The phrase “administered to or at the lumen” is herein defined as delivery to the space in the interior of the intestines. Such delivery can be achieved by a variety of routes (e.g., oral, rectal, etc.) in a variety of vehicles (e.g., tablet, suppository, etc.).
SUMMARY OF THE INVENTION
The present invention relates to therapeutics for the prevention and treatment of IBD. Specifically, the present invention contemplates the prevention and treatment of IBD in humans as well as other animals through the use of polyclonal antibody therapy. The examples of the present invention demonstrate a novel finding that antibodies against TNF are effective (as demonstrated in an experimental model of IBD) during the acute stage of pathogenesis. Some previous work described in the literature has suggested that the use of TNF antibodies in the acute phase of MBD is contraindicated.
In one embodiment, the present invention contemplates a method comprising the administration of polyclonal antibodies which bind to TNF. Preferably, the polyclonal antibody is reactive with TNF across species. Specifically, the present invention demonstrates that immunization with human TNF generates neutralizing antibody capable of reacting with endogenous murine TNF. Thus, the present invention provides anti-TNF antibody that will react with mammalian TNF generally. In another embodiment, the polyclonal antibodies are combined with other reagents (including but not limited to other antibodies).
In another embodiment, the present invention contemplates a method of relieving symptoms of and rescuing mammals (including humans) from episodes of acute or chronic IBD utilizing anti-TNF antibodies.
In another embodiment, the present invention contemplates a method of relieving symptoms of and rescuing mammals (including humans) from episodes of acute or chronic IBD utilizing a combination comprising anti-TNF antibodies. The present invention contemplates a method of treatment, comprising: (a) providing: i) a mammal for treatment, ii) a therapeutic preparation, comprising anti-TNF polyclonal antibodies; and (b) administering said antibodies to the lumen of said mammal.
It is not intended that the present invention be limited to specific preparations of antibodies. However, polyclonal antibodies are preferred. Most importantly, it is preferred that the antibodies not be complement fixing. More specifically, avian antibodies (e.g., chicken antibodies from eggs) are preferred.
The treatment with the antibodies has the unexpected result of reducing mortality rates in animals when administered after the onset of a chronic or acute IBD episode.
DESCRIPTION OF THE DRAWINGS
The single FIGURE, FIG. 1, shows the kinetics of body weights of mice with induced acute colitis.
DESCRIPTION OF THE INVENTION
The present invention relates to therapeutic compositions and methods for the prevention treatment of IBD, and in particular the prevention and treatment of IBD in humans as well as other animals.
The present invention further teaches treatments comprising anti-TNF and compositions and methods used after the onset of symptoms of IBD. As noted above, the present invention also contemplates treatment comprising anti-TNF antibody preparations. In accordance with the present invention, anti-TNF formulations are administered via intravenous, parenteral, rectal or oral route, although the present invention is not limited to these methods of administration.
It is not intended that the present invention be limited by the particular nature of a formulation or combination. The present invention contemplates combinations as simple mixtures as well as chemical hybrids. An example of the latter is where the receptor is covalently linked to a pharmaceutical such as a corticosteroid, or where two receptor types are covalently joined. Covalent binding can be accomplished by any one of many commercially available crosslinking compounds.
It is not intended that the present invention be limited by the particular nature of the therapeutic preparation. For example, such compositions can be provided together with physiologically tolerable liquid, gel or solid carriers, diluents, adjuvants and excipients.
These therapeutic preparations can be administered to mammals for veterinary use, such as with domestic animals, and clinical use in humans in a manner similar to other therapeutic agents. In general, the dosage required for therapeutic efficacy will vary according to the type of use and mode of administration, as well as the particularized requirements of individual hosts.
Such compositions are typically prepared as sprays (e.g. intranasal aerosols) for topical use. However, they may also be prepared either as liquid solutions or suspensions, or in solid forms. Oral formulations (e.g. for gastrointestinal inflammation) usually include such normally employed additives such as binders, fillers, carriers, preservatives, stabilizing agents, emulsifiers, buffers and excipients as, for example, pharmaceutical grades of mannitol, lactose, starch, magnesium stearate, sodium saccharin, cellulose, magnesium carbonate, and the like. These compositions take the form of solutions, suspensions, tablets, pills, capsules, sustained release formulations, or powders, and typically contain 1%-95% of active ingredient, preferably 2%-70%.
The compositions are also prepared as injectables, either as liquid solutions or suspensions; solid forms suitable for solution in, or suspension in, liquid prior to injection may also be prepared.
The antibodies of the present invention are often mixed with diluents or excipients which are physiological tolerable and compatible. Suitable diluents and excipients are, for example, water, saline, dextrose, glycerol, or the like, and combinations thereof. In addition, if desired the compositions may contain minor amounts of auxiliary substances such as wetting or emulsifying agents, stabilizing or pH buffering agents.
Additional formulations which are suitable for other modes of administration, such as topical administration, include salves, tinctures, creams, lotions, and, in some cases, suppositories. For salves and creams, traditional binders, carriers and excipients may include, for example, polyalkylene glycols or triglycerides.
EXPERIMENTAL
The following examples serve to illustrate certain preferred embodiments and aspects of the present invention and are not to be construed as limiting the scope thereof.
EXAMPLE 1
Production of Antibodies to TNF in the Hen
This example involved: (a) preparation of the immunogen and immunization; (b) purification of anti-TNF chicken antibodies from egg yolk (IgY); and (c) detection of anti-TNF antibodies in the purified IgY preparations.
(a) Preparation of the immunogen and immunization. Recombinant human Tumor Necrosis Factor Alpha, (TNF) was purchased (lyophilized without bovine serum albumin (BSA) and designated carrier-free) from R&D Systems Inc., Minneapolis, Minn. and produced in E. coli . The lyophilized TNF was reconstituted in phosphate-buffered saline pH 7.2-7.5 (PBS) at 50 μg/ml and from 2-10 μg of TNF was used to immunize each hen. Each hen received one 0.5 ml sub-cutaneous injection containing TNF with 75 μg Quil A adjuvant (Superfos Biosector, Denmark, distributed by Accurate Chem., Westbury, N.Y.) in PBS. The hens were immunized every 2 weeks for at least 3 times then placed on a maintenance immunization schedule where the hens were immunized every 4-6 weeks.
(b) Purification of anti-TNF chicken antibodies from egg yolk (IgY). Groups of eggs were collected per immunization group at least 3-5 days after the last booster immunization. The chicken yolk immunoglobulin (IgY) was extracted by a two-step polyethylene glycol (PEG) 8000 method performed according to a modification of the procedure of Polson et al., Immunol. Comm . 9:495 (1980). The yolks were separated from the whites and the yolks were placed in a graduated cylinder. The pooled yolks were blended with 4 volumes of PBS and PEG was added to a concentration of 3.5%. When the PEG was dissolved, the protein and lipid precipitates that formed were pelleted by centrifugation at 9,000×g for 15 minutes. The supernatants were decanted and filtered through 4 layers of gauze to remove the floating particulates and a second PEG step was performed by adding PEG to a final concentration of 12% (the supernatants were assumed to contain 3.5% PEG). After a second centrifugation, the supernatants were discarded and the IgY pellets were resuspended in PBS at approximately ⅙ the original yolk volume. IgYs extracted from the eggs of inmunized hens are designated as “immune IgY,” while IgYs extracted from the eggs of unimmunized hens is designated “preimmune IgY.” The concentration of the fractionated IgY's were estimated by measuring the absorbance at 280 nm (an optical density at 280 nm of 1.3 equals 1 mg of IgY/ml. The antibody concentrations were about 25-30 mg/ml.
(c) Detection of anti-TNF antibodies in the purified IgY preparations. In order to determine if anti-TNF response was generated and to determine relative levels of the response, enzyme-linked immunosorbent assays (ELISA) were performed. Briefly, ninety-six well Falcon Pro-bind micro-titer plates were coated overnight at 4° C. with 100 μl/well of TNF at 0.1-1.0 μg/ml PBS. The wells are then blocked with PBS containing 1% BSA and 0.05% Tween 20 and incubated for about 1 hour at 37° C. The blocking solution was removed and the immune or preimmune IgY was diluted in PBS containing BSA and the plates were incubated for 1 hour at 37° C. The plates were washed 3 times with PBS containing 0.05% Tween 20 and three times with PBS alone. Alkaline phosphatase-conjugated anti-chicken IgG was diluted 1:1000 in PBS containing 1% BSA and 0.05% Tween 20, added to the plates and incubated 1 hour at 37° C. The plates were washed as above and p-nitrophenyl phosphate at 1 mg/ml in 0.05 M Na 2 CO 3 , pH 9.5, 10 mM MgCl 2 was added. The plates were read in a Dynatech plate reader at 410 nm about 30 minutes after substrate addition. Good antibody titers (reciprocal of the highest immune IgY generating a signal about 3-fold higher than that of preimmune) ranging from 10,000 to 50,000 was generated.
The level of antibody response in the hens against TNF, given the low amounts of antigen used for immunization, indicates that this protein is very immunogenic in the hens and is a well-suited system to generate anti-mammalian TNF antibodies.
EXAMPLE 2
Rescue from the In Vivo Effects of Acute IBD by the
Administration of Avian Polyclonal Anti-TNF Antibodies
In order to determine whether anti-TNF polyclonal avian antibodies are capable of neutralizing the effects of IBD, a well-characterized and accepted murine model of IBD was utilized using dextran sodium sulfate (DSS). This model simulates UC, and the colitis induced by DSS is characterized by ulceration of the colonic mucosa, blood in the stool and weight loss. Both acute and chronic colitis can be induced in this model. To produce acute colitis, mice are treated with one DSS treatment cycle. Chronic colitis is induced by cycles of 7 days of DSS followed by 7-10 days of water for 2-7 cycles.
This example involves: (a) presentation of mice that exhibit symptoms of acute colitis; and (b) rescue from acute colitis lethality by administration of avian anti-TNF antibody subsequent to IBD onset.
(a) Acute IBD by DSS was induced in Swiss Webster mice (20-25 g), as described by I. Okayasu et al., Gastroenterology 98:694-702 (1990). Drinking water supplemented with 5% dextran sodium sulfate (M.W. 40,000; ICN Biomedicals, Inc., Aurora, Ohio) was given to the animals for 7 days. Within 3-5 days of DSS treatment, the mice began to present with bloody diarrhea, weight loss and colitis.
(b) Two experiments were performed to determine if mice could be rescued from acute colitis lethality using avian anti-TNF. Previous work using a rat anti-mouse TNF monoclonal antibody (G. Kojouharoff, et al., Clin. Exp.Immunology 107:353-358, 1997) or mouse anti-TNF polyclonal antibody (A. D. Olson, et al., J. Pediatric Gastroenterology and Nutrition 21:410-418, 1995) administered parenterally failed to protect acute colitis induced by DSS in mice. The treatment regimen in this example was performed essentially as described by Kojouharoff et al. except, the anti-TNF was administered luminally via the rectum instead of intraperitoneally.
Briefly, for therapeutic purposes in acute colitis, mice were treated twice per day with 0.1 ml. of either anti-TNF alpha or preimmune IgY containing 2-4 mg. of IgY in PBS. The mice were treated rectally using a straight 20 gauge feeding needle (Popper & Sons Inc., New Hyde Park, N.Y.) and a 1 ml syringe after light anesthesia with ether. The mice were treated from day 3 to day 7 during the DDS administration. Untreated mice with DSS induced colitis served as controls. The ability of anti TNF antibody to rescue mice from lethality associated with acute IBD is shown in Table 1. The percent of survival in each of the groups is shown 1 day after termination of DDS and antibody treatment. Note that the use of anti-TNF antibody resulted in a statistically significant increase in animal survival as compared to the untreated and Preimmune controls, with a 100% survival rate for the anti-TNF antibody administration as contrasted with the much lower 52% survival rate for the untreated animals, and 50% for the Preimmune controls.
TABLE 1
Treatment
No. Of Survivors/No. Tested
% Survival
Untreated
22/42
52
Preimmune
5/10
50
Anti-TNF
10/10
100
The above experiment utilized DSS induced colitis positive mice and that were either untreated, or treated with a luminal (rectal) administration of preimmune or anti-TNF antibodies. The anti-TNF survival rate of 100% establishes conclusively a high increase in survival as compared with the 52% and 50% survival rates for both the untreated and Preimmune controls. The results of this experiment proves that avian anti-TNF antibody negates the lethal effect of IBD in vivo and strongly suggests that avian anti-TNF antibody will be useful in preventing or treating IBD.
EXAMPLE 3
Another experiment was performed to confirm the results of Example 2. The procedures used were similar, except that animal weight gain, incidence of diarrhea and presence of blood in the stool using a Hemoccult assay (Smith Kline Diagnostics, Inc., San Jose, Calif.) were monitored in addition to survival rate. The kinetics of body weights of mice with acute colitis in the treatment groups is shown in FIG. 1 . In contrast to the untreated and preimmune-treated mice, body weights were generally higher and increased most rapidly in the anti-TNF treated mice. Interestingly, weight gain in mice treated parenterally with anti-TNFα was reported to be severely delayed after the end of DSS feeding. (See G. Kojouharoff, et al., Clin. Exp.Immunology , cited above).
Three days after the termination of DSS-treatment, stool samples were collected from mice without obvious bloody diarrhea from each group and a Hemoccult test was performed to determine blood in the stool. The results are shown in Table 2. The Hemoccult assay was not performed on mice with obvious bloody stools. These mice and mice with bloody diarrhea that died prior to the Hemoccult testing were considered Hemoccult positive and included in Table 2. The results indicate that anti-TNF IgY effectively prevented blood stools during acute colitis by DSS. In contrast, a previous report (see A. Olson et al.) indicated that anti-TNF serum administered intraperitoneally did not prevent the appearance of blood in the stool of DSS-treated mice.
Table 3 results demonstrate that anti-TNF IgY can effectively prevent mortality and morbidity (diarrhea) in the mice during acute colitis by DSS. The survival rate three days after the termination of DSS treatment in the anti-TNF treated mice was 93%, while survival rates for untreated and preimmune treated mice were 53% and 31%, respectively. In addition, diarrhea was significantly reduced in the anti-TNF treated mice compared to the untreated and preimmune-treated mice. Diarrhea was present in 87% and 92% of the untreated and preimmune treated mice (respectively) while only 21% of the anti-TNF treated mice were afflicted. The results of these treatment studies during acute colitis using DSS in mice demonstrates that luminally delivered anti-TNF antibody is an effective therapy against IBD.
TABLE 2
Anti-TNF Therapy Can Effectively Prevent
Bloody Stools During Acute DSS-Induced Colitis In Mice
No. Of Hemocult
Treatment
Positive/No. Tested
% Hemocult Positive
Untreated
13/15
87
Preimmune
12/13
92
Anti-TNF
3/14
21
TABLE 3
Anti-TNF Therapy Can Effectively Treat
Acute DSS-Induced Colitis In Mice
Treatment
No. Of Survivors/No. Tested
% Survival
% Diarrhea
Untreated
8/15
53
87
Preimmnune
4/13
31
92
Anti-TNF
13/14
93
21
Those skilled in the art will know, or be able to ascertain upon review of the above, using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. These and all other equivalents are intended to be encompassed by the following claims.
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Methods are described for treating inflammatory bowel disease in animals, including humans. Specific avian polyclonal antibodies directed to TNF are shown to have a beneficial effect in animal models predictive of human therapy for the treatment of colitis.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Application No. 60/982,790, filed Oct. 26, 2007, which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] This invention relates to pharmaceutical compositions and methods of making them. More specifically the invention relates to pharmaceutical compositions containing licarbazepine acetate, especially eslicarbazepine acetate.
[0003] Eslicarbazepine acetate is a voltage-gated sodium channel (VGSC) blocker suitable for use as an anticonvulsant for example in treating epilepsy, affective disorders and neuropathic pain.
[0000]
(S)-(−)-10-Acetoxy-10,11-dihydro-5H-dibenz/b,f/azepine-5-carboxamide (eslicarbazepine acetate)
[0004] This molecule is structurally related to carbamazepine and oxcarbazepine, but has been specifically designed to reduce the production of toxic metabolites (such as epoxides) and to avoid enantiomeric impurity, and the unnecessary production of enantiomers or diastereoisomers of metabolites and conjugates, without losing pharmacological activity. It shares with carbamazepine and oxcarbazepine the dibenzazepine nucleus bearing the 5-carboxamide substitute but is differs at the 10,11-position. This molecular variation results in differences in metabolism, preventing the formation of toxic epoxide metabolites, such as carbamazepine-10,11 epoxide.
SUMMARY OF THE INVENTION
[0005] Broadly, the present invention relates to a pharmaceutical composition containing licarbazepine acetate, preferably eslicarbazepine acetate, in combination with at least one pharmaceutically acceptable excipient. The invention also relates to methods of making a pharmaceutical composition containing licarbazepine acetate, preferably eslicarbazepine acetate. The at least one excipient may include conventional excipients, such as one or more diluents/fillers, binders, disintegrants, glidants and lubricants. As used herein the term ‘composition’ is used interchangeably with the term ‘formulation’ and is intended to refer to the final oral dosage form such as a tablet or capsule.
[0006] According to one aspect of the invention, a pharmaceutical composition is provided wherein the composition comprises licarbazepine acetate, preferably eslicarbazepine acetate, in combination with a binder and a disintegrant, wherein the composition comprises granules of the licarbazepine acetate, and wherein at least part of the disintegrant is present in the granules (intragranular) and at least part of the disintegrant is extragranular.
[0007] According to another aspect, the present invention provides a pharmaceutical composition, in the form of an oral dosage form, comprising licarbazepine acetate, preferably eslicarbazepine acetate, wherein the composition does not contain any filler.
[0008] In accordance with another aspect of the invention, there is provided a pharmaceutical composition containing licarbazepine acetate, preferably eslicarbazepine acetate, in combination with at least one pharmaceutically acceptable excipient, wherein the composition does not include a wetting agent (i.e. there is no wetting agent at all in the composition).
[0009] The present invention results in a large increase in the bulk density: from about 0.28 g/mL in the API prior to granulation to, for example, around 0.6 g/mL in the mixture of drug and excipients (i.e. the preparation) prior to forming the final formulation, for example by compression to form a tablet or by capsule filling. Accordingly, another aspect of the present invention provides a pharmaceutical preparation, wherein the preparation comprises licarbazepine acetate, preferably eslicarbazepine acetate, in combination with a binder and a disintegrant, wherein the bulk density of the preparation is at least about 0.3 g/mL. In the preparation the licarbazepine acetate and part of the disintegrant are preferably present in granules whereas the remaining part of the disintegrant is extragranular. The preparation may further comprise extragranular lubricant. Other excipients may also be present as described in the Detailed Description below.
[0010] Preferably the preparation is formed into an oral dosage form, for example by compression to form a tablet.
[0011] Preferably the bulk density of the preparation is at least about 0.35 g/mL, more preferably about 0.40 g/mL, even more preferably about 0.45 g/mL, still more preferably about 0.50 g/mL, yet more preferably about 0.55 g/mL. Most preferably the bulk density of the preparation is at least about 0.60 g/mL.
[0012] The preparation may be used to form a pharmaceutical composition. In some embodiments, the pharmaceutical composition can be in the form of a solid oral dosage form, such as a tablet or capsule.
[0013] Another aspect of the present invention provides a capsule formulation, said formulation comprising a preparation as described above contained in a capsule. The present invention also provides a tablet formulation, said formulation comprising a preparation as described above compressed into a tablet form.
[0014] As a result of the improvement in bulk density the inventors have managed to reduce the size and apparent density of compressed formulations such as tablets. According to a another aspect of the invention, a compressed formulation is provided, preferably a tablet, wherein the formulation comprises licarbazepine acetate, preferably eslicarbazepine acetate, in combination with a binder and a disintegrant, wherein the formulation has an apparent density of about 0.5 to about 1.5 g/mL.
[0015] Preferably the apparent density of the formulation is about 0.6 to about 1.4 g/mL, more preferably about 0.7 to about 1.3 g/mL, most preferably about 0.8 to about 1.2 g/mL.
[0016] Preferably the formulation is comprised of granules, wherein the licarbazepine acetate is intragranular. Preferably the formulation also comprises a disintegrant and a binder. More preferably part of the disintegrant is present in the granules and the remaining part is extragranular. Other excipients may also be present as described in the Detailed Description below.
[0017] It has also been found that the use of a granulation process to produce the pharmaceutical composition according to the invention, rather than a direct compression process, results in improved flow and compressibility properties of the licarbazepine acetate. Both wet and dry granulation processes improved compressibility. However, unexpectedly, when the granulation process was scaled up to an industrial scale, the flowability of the licarbazepine acetate was unsatisfactory when using the dry granulation method; only the wet granulation process improved flowability.
[0018] Thus, according to another aspect of the invention there is provided a process for preparing a pharmaceutical composition, preferably an oral dosage form, comprising the following steps: mixing licarbazepine acetate, preferably eslicarbazepine acetate, with a pharmaceutically acceptable granulation liquid, and optionally with one or more excipients; granulating the eslicarbazepine acetate and the granulation liquid; optionally mixing the granules with one or more suitable excipients to form a preparation; and forming an oral dosage form.
[0019] The optional excipients can be one or more selected from binder, filler/diluent, disintegrant, lubricant and glidant.
[0020] In a preferred embodiment, the granulation step also comprises drying the licarbazepine acetate and granulation liquid mixture.
[0021] Although the wet granulation process is effective to solve the flowability problems associated with direct compression, there can be problems with binding when the process is scaled up to an industrial scale. It has been found that these problems can be solved by using a wet granulation process in which part of the binder is mixed with the licarbazepine acetate, for example in a powder form, and the remaining part is present in the granulation liquid.
[0022] Accordingly, another aspect of the present invention provides a process for preparing a pharmaceutical composition, preferably an oral dosage form, comprising the steps of: mixing licarbazepine acetate, preferably eslicarbazepine acetate, with at least one excipient including part of the total amount of binder; providing a granulation liquid; dissolving or dispersing the remaining proportion of the total amount of the binder in the granulation liquid; granulating the mixture from the mixing step using the granulation liquid produced in the dissolving or dispersing step to produce granules; and optionally forming an oral dosage form.
[0023] The process may comprise an additional step involving contacting the granules with one or more suitable excipients, for example, prior to forming the oral dosage form.
[0024] Preferably the licarbazepine acetate is mixed with about 20 to about 80 wt % (with respect to the total weight of the composition) binder, more preferably about 20 to about 80 wt % binder, even more preferably about 40 to about 70 wt % binder, most preferably about 30 to about 70 wt % binder, whilst the remainder of the binder is dissolved or dispersed in the granulation liquid, for example about 20 to about 80 wt % of the total weight of the binder may be present in the granulation liquid.
[0025] Preferably the binder mixed with the licarbazepine acetate is in the form of a powder, preferably a dry powder. A dry powder as used herein has a liquid (e.g. water) content of less than about 15%.
[0026] Preferably the one or more suitable excipients includes a disintegrant. Preferably the one or more excipients includes a lubricant. Additional excipients may include one or more of diluent/filler, glidant, sweetener, and flavouring.
[0027] In a more preferred embodiment a portion of the disintegrant is mixed with the licarbazepine acetate prior to the granulating step and the remaining portion is contacted with the granules prior to forming the dosage form.
[0028] Where a sweetener is to be used, it is preferred that the sweetener is mixed with the licarbazepine acetate, prior to mixing with the granulation liquid (i.e. the sweetener is intended to be intragranular).
[0029] Where a flavouring agent is to be used, it is preferred that the flavouring agent is mixed with the licarbazepine acetate granules formed in the granulation step (i.e. the flavouring agent is intended to be extragranular).
[0030] Suitable granulation liquids include water, a lower alcohol such as ethanol or a mixture thereof.
[0031] Preferably the process further involves a drying step, in particular the granules may be dried following the granulation step. The drying step may also be followed by a screening step wherein the granules are screened for example, by size or shape.
[0032] Preferably the oral dosage form is a tablet. In this embodiment, forming the oral dosage form involves compressing the mixture of granules and excipient(s).
[0033] Alternatively the oral dosage form is a capsular form and the forming step involves filling a suitable capsule with the granules and/or excipients.
DETAILED DESCRIPTION OF THE INVENTION
[0034] In terms of physical properties, eslicarbazepine acetate shows marked differences to carbamazepine and oxcarbazepine, resulting in different challenges for the galenical chemist. For example, oxcarbazepine, carbamazepine and eslicarbazepine acetate have different crystal forms and in fact, carbamazepine and oxcarbazepine each show several different crystal forms. Drugs with different crystal forms present differences in dissolution, particle size, bulk density and flow properties, all characteristics which influence the formulation process. For example, differences in drugs' crystal shape and in the size of drug particles affect the drugs' relative solubility and dissolution rates, presenting new challenges to the formulation chemist, particularly in terms of disintegration of the formulation. Crystal form and particle size also affect cohesiveness of the particles which in turn affects formation of tablets and binding of particles during granulation.
[0035] Licarbazepine acetate is optically active, existing in two enantiomeric forms. In this specification the expression ‘licarbazepine acetate’ encompasses the individual R- and S-isomers, the racemic mixture of the isomers, and also non-racemic mixtures of the R- and S-isomers in any proportion. In this specification “R-licarbazepine acetate” means the R-isomer in substantially pure form, i.e., at least about 90% pure, preferably at least about 95% pure, more preferably at least about 98% pure, and most preferably at least about 99% pure. In this specification “eslicarbazepine acetate” or “S-licarbazepine acetate” means the S-isomer in substantially pure form, i.e., at least about 90% pure, preferably at least about 95% pure, more preferably at least about 98% pure, and most preferably at least about 99% pure.
[0036] Further description of licarbazepine acetate, methods of manufacture, and some of its uses are described in U.S. Pat. No. 5,753,646, U.S. Pat. No. 7,119,197, U.S. Pat. No. 7,241,886, U.S. Pat. No. 7,189,846, U.S. Publication No. 20080081930, WO2006/005951, US Publication No. 20080139807, US Publication No. 20060252745, US Publication No. 20060252746, WO2007/012793, WO2007/094694, and WO2007/117166, which are incorporated herein by reference in their entirety.
[0037] Certain physical properties of licarbazepine acetate cause problems for its formulation on large-scale, in particular for formation of a tablet formulation, which is preferred for reasons of ease of administration and dosage control. The compound has extremely low bulk density (less than about 0.3 g/mL). This low bulk density means that the compound exhibits poor flowability and can be therefore difficult to handle, particularly on an industrial scale. Moreover, the compound can be difficult to compress and results in very large tablet sizes. The tablets can also show very poor dissolution.
[0038] The inventors were able to improve dissolution on a laboratory scale by adding a disintegrant prior to granulating the eslicarbazepine acetate. However, they surprisingly discovered that when part of the disintegrant was added to the mixture after granulating, the dissolution was improved.
[0039] In order to reduce the tablet size, the amount of filler can be reduced or eliminated. Substances acting as fillers often have additional effects such as binding, which may lead to unsatisfactory binding and consequent poor technological properties, such as hardness or friability.
[0040] Binders generally function more effectively when they are used as liquids or dispersions. However, the inventors found that the problems described above could be solved by preparing the tablet using a wet granulation process in particular, one in which part of the binder is dissolved or dispersed in the granulation liquid, and the rest of the binder is added as a powder with the licarbazepine acetate. Surprisingly, the bulk density of the granulate produced from this mixture was more than double that of the raw drug material prior to granulation.
[0041] Additionally, in another aspect, the present invention discloses that inclusion of part of the disintegrant intragranular and part extragranular improved dissolution.
Dosage Form
[0042] Preferably the composition is an oral dosage form, more preferably a solid oral dosage form such as a capsule or a tablet. Preferably the solid oral dosage form is a tablet. The tablet can be coated.
Disintegrant
[0043] A disintegrant is a substance which helps the composition break up once ingested. Preferably the total weight of the composition is comprised of about 0.5 to about 70 wt % disintegrant, more preferably about 0.5 to about 20 wt % disintegrant, more preferably about 3 to about 15 wt % disintegrant, about 2 to about 15 wt %, or about 2 to about 8 wt %.
[0044] About 0 to about 100 wt % of the total amount of the disintegrant can be present in the granules. More preferably, about 20 to about 80 wt % of the total amount of the disintegrant is present in the granules. More preferably about 30 to about 70 wt % of the total amount of the disintegrant is present in the granules. More preferably about 40 to about 60 wt % of the total amount of the disintegrant is present in the granules. More preferably about 45 to about 55 wt % of the total amount of the disintegrant is present in the granules. Most preferably about 50 wt % of the total amount of the disintegrant is present in the granules. The remaining proportion of the disintegrant is preferably present extragranular.
[0045] In a most preferred embodiment, the disintegrant is present both in the granules and extragranular.
[0046] Suitable disintegrants include alginic acid (Kelacid™, Protacid™, Satialgine H8™), calcium phosphate, tribasic (Tri-Cafos™, TRI-CAL WG™, TRI-TAB™), carboxymethylcellulose calcium (ECG 505™, Nymcel ZSC™), carboxymethylcellulose sodium (Akucell™, Aquasorb™, Blanose™, Finnfix™, Nymcel Tylose CB™), colloidal silicon dioxide (Aerosil™, Cab-O-Sil™, Cab-O-Sil M-5P™, Wacker HDK™), croscarmellose sodium (Ac-Di-SoI™, Explocel™, Nymcel ZSX™, Pharmacel XL™, Primellose™, Solutab™, Vivasol™), crospovidone (Kollidon CL™, Kollidon CL-M™, Polyplasdone XL™, Polyplasdone XL-IO™), docusate sodium, guar gum (Galactosol™, Meprogat™, Meyprodor™, Meyprofin™, Meyproguar™), low substituted hydroxypropyl cellulose, magnesium aluminum silicate (Carrisorb™, Gelsorb™, Magnabite™, Neusilin™, Pharmsorb™, Veegum™), methylcellulose (Benecel™, Culminal MC™, Methocel™, Metolose™), microcrystalline cellulose (Avicel PH™, Celex™, Celphere™, Ceolus KG™, Emcoel™, Ethispheres™, Fibrocel™, Pharmacel™, Tabulose™, Vivapur™), povidone (Kollidon™, Plasdone™) sodium alginate (Kelcosol™, Keltone™, Protanal™), sodium starch glycolate (Explotab™, Primojel™, Vivastar P™), polacrilin potassium (Amberlite IRP88™), silicified microcrystalline cellulose (ProSolv™), starch (Aytex P™, Fluftex W™, Instant Pure-Cote™, Melojel™, Meritena™, Paygel 55™, Perfectamyl D6PH™, Pure-Bind™, Pure-Cote™, Pure-Dent™, Pure-Gel™, Pure-Set™, Purity 21™, Purity 826™, Tablet White™) or pre-gelatinized starch (Instanstarch™, Lycatab C™, Lycatab PGS™, Merigel™, National 78-1551™, Pharma-Gel™, Prejel™, Sepistab ST 200™, Spress B820™, Starch 1500 G™, Tablitz™, Unipure LD™ and Unipure WG220™), or mixtures thereof.
[0047] Preferred disintegrants are super-disintegrants such as croscarmellose sodium, crospovidone, low substituted hydroxypropyl cellulose, microcrystalline cellulose, carboxymethylcellulose sodium, carboxymethylcellulose calcium and sodium starch glycolate. A particularly suitable disintegrant is croscarmellose sodium. When the disintegrant is croscarmellose sodium, the total weight of the composition is preferably comprised of about 0.5 to about 20 wt %, more preferably about 2 to about 15 wt %, most preferably about 3 to about 15 wt % disintegrant.
Binder
[0048] A binder is a substance which holds the components of the composition together in the required composition form.
[0049] Preferably the total weight of the composition is comprised of about 0.5 to about 70 wt % binder, more preferably about 0.5 to about 20 wt %, more preferably about 1 to about 14 wt %, still more preferably about 5 to about 9 wt % binder.
[0050] Suitable binders for inclusion in the composition of the invention include acacia, alginic acid (Kelacid™, Protacid™, Satialgine H8™), carbomer (Acritamer™, Carbopol™, Pemulen™, Ultrez™), carboxymethylcellulose sodium (Akucell™, Aquasorb™, Blanose™, Finnfix™, Nymcel™, Tylose™), ceratonia (Meyprofleur™), cottonseed oil, dextrin (Avedex™, Caloreen™, Crystal Gum™, Primogran W™), dextrose (Caridex™, Dextrofm™, Lycedex PF™, Roferose™, Tabfme D-IOO™), gelatin (Cryogel™, Instagel™, Solugel™), guar gum (Galactosol™, Meprogat™, Meyprodor™, Meyprofm™, Meyproguar™), hydrogenated vegetable oil type I (Akofine™, Lubritab™, Sterotex™, Dynasan P[omicron]O™, Softisan 154™, Hydrocote™, Lipovol™, HS-K™, Sterotex HM™), hydroxyethyl cellulose (Alcoramnosan™, Cellosize™, Idroramnosan™, Liporamnosan™, Natrosol™, Tylose PHA™), hydroxyethylmethyl cellulose (Culminal™, Tylopur MH™, Tylopur MHB™, Tylose MB™, Tylose MH™, Tylose MHB™), hydroxypropyl cellulose (Klucel™, Methocel™, Nisso HPC™), low substituted hydroxypropyl cellulose, hypromellose (Benecel MHPC™, Methocel™, Metolose™, Pharmacoat™, Spectracel 6™, Spectracel 15™, Tylopur™), magnesium aluminium silicate (Carrisorb™, Gelsorb™, Magnabite™, Neusilin™, Pharmsorb™, Veegum™), maltodextrin (C*Dry MD™, Glucidex™, Glucodry™, Lycatab DSH™, Maldex™, Maltagran™, Maltrin™, Maltrin QD™, Paselli MD 10 PH™, Star-Dri™) maltose (Advantose 100™), methylcellulose (Benecel™, Culminal MC™, Methocel™, Metolose™), microcrystalline cellulose (Avicel PH™, Celex™, Celphere™, Ceolus KG™, Emcocel™, Ethispheres™, Fibrocel™, Pharmacel™, Tabulose™, Vivapur™), polydextrose (Litesse™), polyethylene oxide (Polyox™), polymethacrylates (Eastacryl 30D™, Eudragit™, Kollicoat MAE 30D™, Kollicoat MAE 30DP™), povidone (Kollidon™, Plasdone™), sodium alginate (Kelcosol™, Keltone™, Protanal™), starch (Aytex P™, Fluftex W™, Instant Pure-Cote™, Melojel™, Meritena Paygel 55™, Perfectamyl D6PH™, Pure-Bind™, Pure-Cote™, Pure-Dent™, Pure-Gel™, Pure-Set™, Purity 21™, Purity 826™, Tablet White™), pregelatinised starch (Instastarch™, Lycatab C™, Lycatab PGS™, Merigel™, National 78-1551™, Pharma-Gel™, Prejel™, Sepistab ST 200™, Spress B820™, Starch 1500 G™, Tablitz™, Unipure LD™, Unipure WG 220™), stearic acid (Crodacid™, Emersol Hystrene™, Industrene™, Kortacid 1895™, Pristerene™), sucrose and zein, or mixtures thereof.
[0051] Preferred binders include povidone, hypromellose, hydroxypropyl cellulose, methyl-cellulose, ethyl-cellulose, pregelatinised maize starch and gelatine. The most preferred binder is povidone. When the binder is povidone, the total weight of the composition is preferably comprised of about 0.5 to about 14 wt % binder, preferably about 5 to about 9 wt % binder.
Lubricant
[0052] The presence of a lubricant is particularly preferred when the composition is a tablet as lubricants improve the tabletting process. Lubricants prevent composition ingredients from clumping together and from sticking to the tablet punches or capsule filling machine and improve flowability of the composition mixture. Accordingly, the total weight of the composition may also preferably be comprised of about 0.1 to about 10 wt % lubricant, more preferably about 1 to about 3 wt % lubricant.
[0053] Suitable lubricants include calcium stearate (HyQual™), glycerine monostearate (Capmul GMS-50™, Cutina GMS™, Imwitor™ 191 and 900, Kessco GMS5™ Lipo GMS™ 410, 450 and 600, Myvaplex 600P™, Myvatex™, Protachem GMS-450™, Rita GMS™, Stepan GMS™, Tegin™, Tegin™ 503 and 515, Tegin 4100™, Tegin M™, Unimate GMS™), glyceryl behenate (Compritol 888 ATO™), glyceryl palmitostearate (Precirol ATO 5™), hydrogenated castor oil (Castorwax™, Castorwax MP 70™, Castorwax MP 80™, Croduret™, Cutina HR™, Fancol™, Simulsol 1293™), hydrogenated vegetable oil type I (Akofine™, Lubritab™, Sterotex™, Dynasan P60™, Softisan 154™, Hydrocote™, Lipovol HS-K™, Sterotex HM™), magnesium lauryl sulphate, magnesium stearate, medium-chain triglycerides (Captex 300™, Captex 355™, Crodamol GTC/C™, Labrafac CC™, Miglyol 810™, Miglyol 812™, Myritol™, Neobee M5™, Nesatol™, Waglinol 3/9280™), poloxamer (Lutrol™, Monolan™, Pluronic™, Synperonic™), polyethylene glycol (Carbowax™, Carbowax Sentry™, Lipo™, Lipoxol™, Lutrol E™, Pluriol E™), sodium benzoate (Antimol™), sodium chloride (Alberger™), sodium lauryl sulphate (Elfan 240™, Texapon Kl 2P™), sodium stearyl fumarate (Pruv™), stearic acid (Crodacid E570™, Emersol™, Hystrene™. Industrene™, Kortacid 1895™, Pristerene™), talc (Altaic™, Luzenac™, Luzenac Pharma™, Magsil Osmanthus™, Magsil Star™, Superiore™), sucrose stearate (Surfhope SE Pharma D-1803 F™) and zinc stearate (HyQual™), or mixtures thereof.
[0054] Preferred lubricants include magnesium stearate and/or sodium lauryl sulphate. In a most preferred embodiment the lubricant is magnesium stearate.
Glidant
[0055] Glidants improve the flowability of the composition. The composition may also comprise a glidant. Preferably, the total weight of the composition is comprised of about 0 to about 10 wt %, glidant.
[0056] Suitable glidants include tribasic calcium phosphate (Tri-Cafos™, TRI-CAL™, TRI-TAB™), calcium silicate, cellulose, powdered (Arbocel™, Elcema™, Sanacel™, Solka-Floc™), colloidal silicon dioxide (Aerosil™, Cab-O-Sil™, Cab-O-Sil M-5P™, Wacker HDK™), magnesium silicate, magnesium trisilicate, starch (Aytex P™, Fluftex W™, Instant Pure-Cote™, Melojel™, Meritena™, Paygel 55™, Perfectamyl D6PH™, Pure-Bind™, Pure-Cote™, Pure-Dent™. Pure-Gel™, Pure-Set™, Purity 21™, Purity 826™, Tablet White™) and talc (Altaic™, Luzenac™, Luzenac Pharma™, Magsil Osmanthus™, Magsil Star™, Superiore™), or mixtures thereof.
[0057] Preferred glidants are colloidal silicon dioxide and/or talc.
Diluent/Filler
[0058] The term ‘filler’ and the term ‘diluent’ are herein used interchangeably. It is known that, in general, the term ‘filler’ is used in the context of capsular formulations and the term ‘diluent’ in tablet formulations. Fillers fill out the size of a composition, making it practical to produce and convenient for the consumer to use.
[0059] The composition may comprise a diluent/filler, which may be present in an amount up to about 70 wt % of the total weight of the composition.
[0060] When present in the composition, suitable fillers include for example calcium carbonate (Barcroft™, Cal-Carb™, CalciPure™, Destab™, MagGran™, Millicarb™, Pharma-Carb™, Precarb™, Sturcal™, Vivapres Ca™), calcium phosphate, dibasic anhydrous (A-TAB™, Di-Cafos A-N™, Emcompress Anhydrous™, Fujicalin™), calcium phosphate, dibasic dihydrate (Cafos™, Calipharm™, Calstar™, Di-Cafos™, Emcompress™), calcium phosphate tribasic (Tri-Cafos™, TRI-CAL WG™, TRI-TAB™), calcium sulphate (Destab™, Drierite™, Snow White™, Cal-Tab™, Compactrol™, USG Terra Alba™), cellulose powdered (Arbocel™, Elcema™, Sanacel™, Solka-Floc™), silicified microcrystalline cellulose (ProSolv™), cellulose acetate, compressible sugar (Di-Pac™), confectioner's sugar, dextranes (Candex™, Emdex™), dextrin (Avedex™, Caloreen™, Crystal Gum™, Primogran W™), dextrose (Caridex™, Dextrofin™, Lycadex PF™, Roferose™, Tab fine D-IOO™), fructose (Advantose™, Fructamyl™, Fructofin™, Krystar™), kaolin (Lion™, Sim 90™), lactitol (Finlac ACX™, Finlac DC™, Finlac MCX™), lactose (Aero Flo 20™, Aero Flo 65™, Anhydrox™, CapsuLac™, Fast-Flo™, FlowLac™, GranuLac™, InhaLac™, Lactochem™, Lactohale™, Lactopress™, Microfine™, Microtose™, Pharmatose™, Prisma Lac™, Respitose™, SacheLac™, SorboLac™, Super-Tab™, Tablettose™, Wyndale™, Zeparox™), magnesium carbonate, magnesium oxide (MagGran MO™), maltodextrin (C*Dry MD™, Glucidex™, Glucodry™, Lycatab DSH™, Maldex™, Maltagran™, Maltrin™, Maltrin QD™, Paselli MD 10 PH™, Star-Dri™), maltose (Advantose 100™), mannitol (Mannogem™, Pearlitol™), microcrystalline cellulose (Avicel PH™, Celex™, Celphere™, Ceolus KG™, Emcocel™, Ethispheres™, Fibrocel™, Pharmacel™, Tabulose™, Vivapur™), polydextrose (Litesse™), simethicone (Dow Corning Q7-2243 LVA™, Cow Corning Q7-2587™, Sentry Simethicone™), sodium alginate (Kelcosol™, Keltone™, Protanal™), sodium chloride (Alberger™), sorbitol (Liponec 70-NC™, Liponic 76-NCv, Meritol™, Neosorb™, Sorbifin™, Sorbitol Instant™, Sorbogem™), starch (Aytex P™, Fluftex W™, Instant Pure-Cote™, Melojel™, Meritena Paygel 55™, Perfectamyl D6PH™, Pure-Bind™, Pure-Cote™, Pure-Dent™, Pure-Gel™, Pure-Set™, Purity 21™, Purity 826™, Tablet White™), pregelatinized starch (Instastarch™, Lycatab C™, Lycatab PGS™, Merigel™, National 78-1551™, Pharma-Gel™, Prejel™, Sepistab ST 200™, Spress B820™, Starch 1500 G™, Tablitz™, Unipure LD™, Unipure WG220™), sucrose, trehalose and xylitol (Klinit™, Xylifm™, Xylitab™, Xylisorb™, Xylitolo™), or mixtures thereof.
[0061] The diluent/filler is preferably selected from calcium phosphate, dibasic dehydrate, microcrystalline cellulose or lactose. Alternatively, any suitable diluent/filler can be used.
[0062] However, in a most preferred embodiment, the composition does not contain any filler/diluent.
Flavouring/Sweetening Agent
[0063] In an embodiment, the composition further includes a flavouring and/or a sweetening agent, each of which may be present in an amount of about 0.1 to about 2 wt % of the total weight of the composition.
[0064] The presence of these excipients is particularly desirable in pediatric compositions. Suitable flavouring agents include chocolate, bubble gum, cocoa, coffee, fruit flavouring (such as wild cherry, banana, grape, peach, and, raspberry), oil of peppermint, oil of spearmint, oil of orange, mint flavour, anise flavour, honey flavour, vanilla flavour, tea flavour and verbena flavour, and various fruit acids such as citric acid, ascorbic acid and tartaric acid, or mixtures thereof.
[0065] The raspberry flavour and the banana flavour have been found to yield particularly palatable products. When the flavouring agent is banana flavour, the total weight of the composition is comprised of about 0.1 to about 3 wt % flavouring agent
[0066] Preferably about 30 to about 100 wt %, more preferably about 60 to about 100 wt %, even more preferably about 80 to about 100 wt % of the total amount of the flavouring agent is present extra-granular. The remaining proportion of flavouring agent is intragranular. Preferably either all or the majority (at least about 50 wt %) of the flavouring agent is extragranular.
[0067] Suitable sweetening agent(s) is (are) selected from gluconate, aspartame, cyclamate, sodium saccharine, xylitol and maltitol, or mixtures thereof. Preferably, the sweetening agent is aspartame or sodium saccharine. When the sweetening agent is sodium saccharine, the total weight of the composition is comprised of about 0.1 to about 5 wt % sweetening agent.
[0068] Preferably about 20 to about 100 wt % of the total amount of the sweetening agent is intragranular. More preferably, about 50 to about 100 wt % of the total amount of the sweetening agent is intragranular. Most preferably about 80 to about 100 wt % of the total amount of the sweetening agent is present intragranular. The remaining proportion of sweetening agent is extragranular. Preferably either all or the majority (at least about 50 wt %) of the sweetening agent is intragranular.
Wetting Agent
[0069] A wetting agent is an excipient that decreases the contact angle of a solid particle in liquid medium, thus improving drug solubility and dissolution in solid formulations.
[0070] The composition may optionally further comprise a wetting agent. However, in a preferred embodiment the composition does not contain any wetting agent. In particular the composition does not include any sodium lauryl sulphate.
[0071] When present in the composition, suitable wetting agents include for example gelatin, casein, lecithin (phosphatides), gum acacia, cholesterol, tragacanth, stearic acid, benzalkonium chloride, calcium stearate, glycerol monostearate, cetostearyl alcohol, cetomacrogol emulsifying wax, sorbitan esters, polyoxyethylene alkyl ethers (e.g., macrogol ethers such as cetomacrogol 1000), polyoxyethylene castor oil derivatives, polyoxyethylene sorbitan fatty acid esters (also known as polysorbates) (e.g., TWEEN™), polyethylene glycols, polyoxyethylene stearates, phosphates, sodium lauryl sulphate, poloxamer, sodium dodecylsulfate, carboxymethylcellulose calcium, carboxymethylcellulose sodium, methylcellulose, hydroxyethylcellulose, hydroxyl propylcellulose, hydroxypropylmethylcellulose phthalate, noncrystalline cellulose, magnesium aluminum silicate, triethanolamine, polyvinyl alcohol, polyvinylpyrrolidone (also known as PVP), yloxapol (also known as superinone or triton), and combinations thereof.
[0072] In general, excipients mixed with the licarbazepine prior to granulation are intragranular and may include one or more of diluent/filler, disintegrant, sweetener, flavouring agent and, binder. Those excipients which are contacted with the granules prior to forming the oral dosage form (i.e. are added after granulation) are, in general, extragranular and include one or more of filler/diluent, disintegrant, lubricant, flavouring agent, sweetener and glidant. In this way excipients can be extra- and/or intragranular.
Density
[0073] Preferably the bulk density of the preparation is at least about 0.35 g/mL, more preferably at least about 0.40 g/mL, even more preferably at least about 0.45 g/mL, still more preferably at least about 0.50 g/mL, yet more preferably at least about 0.55 g/mL. Most preferably the bulk density of the preparation is at least about 0.60 g/mL.
[0074] Suitable methods for determining the bulk density of the preparation will be well known to the skilled chemist, for example, the European Pharmacopeia edition 6, Test 2.9.15 “apparent volume”, pages 285-286, EDQM, 2007, or USP 31, vol. 1 test <616> page 231-232, The United States Pharmacopeia Convention, 2008. The apparent density of a compressed formulation is measured in terms of mass and volume of the formulation and is well within the capabilities of the skilled person.
[0075] A suitable method is described below:
Apparatus
settling apparatus capable of producing in 1 minute 250±15 taps from a height of 3±0.2 mm. The support for the graduated cylinder with its holder, has a mass of 450±5 g a 250 ml graduated cylinder (2 ml intervals) with a mass of 220±40 g
Method Into a dry cylinder, introduce without compacting, 100.0 g (m g) of the test substance. Secure the cylinder in its holder. Read the unsettled apparent volume (V 0 ) to the nearest milliliter. Carry out 10, 500 and 1250 taps and read the corresponding volumes V 10 , V 500 , V 1250 , to the nearest milliliter. If the difference between V 500 and V 1250 is greater than 2 ml, carry out another 1250 taps.
[0081] Alternatively, if it is not possible to select 100 g, select a test sample of any mass but with a volume between 50 ml and 250 ml, measure its apparent volume, V 0 as described above, and weigh the sample and specify the mass in the expression of results.
[0082] Bulk/apparent density may then be determined in g/ml using the following formula:
[0000] m/V 0
[0000] where m is the mass in grams and V 0 the unsettled apparent volume
[0083] Preferred features and embodiments of each aspect of the invention are as for each of the other aspects mutatis mutandis unless the context demands otherwise. For example, the majority of preferred features are applicable both to tablet and to capsular dosage forms.
EXAMPLES
[0084] The invention will be further described with reference to the following examples.
Exemplary Compositions
Example 1
[0085]
[0000]
Eslicarbazepine acetate
55-60%
Diluent
30-40%
Binder
4-6%
Disintegrant
6-8%
Lubricant
0.5-1.5%
Example 2
[0086]
[0000]
Eslicarbazepine acetate
70-75%
Diluent
12-16%
Binder
4-6%
Disintegrant
5-7%
Lubricant 1
0.5-1.5%
Lubricant 2
0.5-1.5%
Example 3
[0087]
[0000]
Eslicarbazepine acetate
82-89%
Binder
7-9%
Disintegrant
5-7%
Flavouring agent
0.4-0.6%
Sweetening agent
0.6-0.9%
Lubricant
0.5-1.5%
Example 4
[0088]
[0000]
Eslicarbazepine acetate
82-89%
Binder
5-8%
Disintegrant
5-8%
Lubricant
1-3%
Specific Examples
Example 5—Dry Granulation Formulation
[0089]
[0000]
Eslicarbazepine acetate
35-45 wt %
Microcrystalline cellulose
40-60 wt %
Croscarmellose sodium (intragranular)
5-15 wt %
Magnesium stearate
0.3-2.0 wt %
Talc
1.0-wt 5%
Magnesium stearate
0.1-wt 2.0%
Example 6—Wet Granulation Formulation (i)
[0090]
[0000]
Eslicarbazepine acetate (intragranular)
5-70 wt %
Emcompress ® (intragranular)
20-85 wt %
Povidone
1-10 wt %
Croscarmellose sodium ( 1/2 intra-/ 1/2 extragranular)
1-10 wt %
Ethanol 96%
q. ad.
Magnesium stearate (extragranular)
0.1-2.5 wt %
Example 7—Wet Granulation Formulation (ii)
[0091]
[0000]
Eslicarbazepine acetate (intragranular)
65-85 wt %
Emcompress ® (intragranular)
10-30 wt %
Povidone( 1/2 powder/ 1/2 dispersion)
1-10 wt %
Croscarmellose sodium ( 1/2 intra-/ 1/2 extragranular)
1-10 wt %
Ethanol 96%
q. ad.
Magnesium stearate (extragranular)
0.1-2.5 wt %
Sodium Lauryl sulphate (extragranular)
0.1-2.5 wt %
Example 8—Wet Granulation Formulation (iii)
[0092]
[0000]
Eslicarbazepine acetate (intragranular)
65-85 wt %
Emcompress ® (intragranular)
5-30 wt %
Microcrystalline cellulose (intragranular)
5-70 wt %
Povidone (100% powder)
1-10 wt %
Croscarmellose sodium ( 1/2 intra-/ 1/2 extragranular)
1-10 wt %
Ethanol 96%
q. ad.
Magnesium stearate (extragranular)
0.1-2.5 wt %
Example 9—Formulation with Flavourings and Sweeteners
[0093]
[0000]
Eslicarbazepine acetate (intragranular)
70-90 wt %
Povidone ( 1/2 powder/ 1/2 dispersion)
2-15 wt %
Croscarmellose sodium ( 1/2 intra-/ 1/2 extragranular)
2-15 wt %
Ethanol 96%
q. ad.
Magnesium stearate (extragranular)
0.1-2.5 wt %
Banana flavour (extragranular)
0.1-2.0 wt %
Sodium saccharin (intragranular)
0.1-2.0 wt %
Example 10
[0094]
[0000]
Eslicarbazepine acetate (intragranular)
80-90 wt %
Povidone ( 1/2 powder/ 1/2 dispersion)
3-10 wt %
Croscarmellose sodium ( 1/2 intra-/ 1/2 extragranular)
3-10 wt %
Purified water
q. ad.
Magnesium stearate (extragranular)
0.1-3.0 wt %
[0095] Tablets were made on both small and industrial scale as follows.
Small Scale/Semi-Industrial
[0096] Eslicarbazepine acetate was mixed with half of the binder, povidone, and half of the disintegrant, croscarmellose sodium, in a blender for 10 minutes. The remaining half of the povidone was dispersed in purified water. The eslicarbazepine acetate, povidone-disintegrant mixture was then wet with the purified water before granulation (Ø1.6 mm). The granules were dried on a tray drier with extraction at 50° C. to a moisture content between 1.0-3.0%. The granules were then calibrated. The calibrated granules were added to the other half of the croscarmellose sodium and mixed for 10 minutes in a blender. The lubricant, magnesium stearate, was added and the final mixture mixed for 5 minutes before compression into tablets.
Industrial Scale
[0097] Eslicarbazepine acetate, half of the binder, povidone, and half of the disintegrant, croscarmellose sodium, were added to a high shear mixer/granulator. The remaining povidone was dispersed in the granulation fluid (water) and added to the granulator for wet granulation. The granules formed were unloaded and dried on a fluid bed drier at 66° C. the granules to a moisture content of between 1.0-3.0%). The dried granules were then calibrated (Ø1.0 mm). The calibrated granules were added the other half of croscarmellose sodium and mixed for 10 minutes in a blender. The lubricant, magnesium stearate, was added and the final mixture mixed for 5 minutes, before compression into tablets.
[0000] Comparison of Tablet Characteristics after Wet and Dry Granulation
Composition and Manufacturing Process for Wet and Dry Granulation Experiments
[0098]
[0000]
Starting
Quantity
materials
(mg/tablet)
Function
Manufacturing process
Eslicarbazepine
600.0
Active
Wet granulation process
acetate
substance
Blend eslicarbazepine acetate, emcompress, povidone
Emcompress ®
300.0
Diluent
and 1/2 croscarmellose sodium in a suitable blender, for
Povidone
50.0
Binder
10 minutes at 25 r.p.m.
Croscarmellose
70.0
Disintegrant
Wet the mixture with ethanol. Granulate. Dry (40° C.)
sodium
and calibrate through a Ø 1.0 mm sieve.
Magnesium
10.0
Lubricant
Add the remaining croscarmellose sodium and blend
stearate
for 10 min. at 25 r.p.m.
Final tablet
1030
Add magnesium stearate to the previous mixture and
weight
blend for 5 more minutes at 25 r.p.m.
Compress the final mixture using oblong punches
Dry granulation process
Blend eslicarbazepine acetate, emcompress, povidone
and 1/2 croscarmellose sodium in a suitable blender, for
10 minutes at 25 r.p.m
Add 1/2 of magnesium stearate to the mixture and blend
for 5 min. at 25 r.p.m.
Compress the mixture without control of the weight
and hardness of the tablets obtained.
Break the tablets in a suitable granulator and pass the
obtained granules primarelly in a Ø 1.6 mm sieve and
then through a Ø 1.0 mm sieve.
Add the remaining croscarmellose sodium and blend
for 10 minutes at 25 r.p.m. Add the second portion of
magnesium stearate and mix for 5 minutes at 25 r.p.m.
Compress the final mixture using oblong punches.
Results
[0099]
[0000]
Batch
Wet
Dry
Method
Bulk density
0.49
0.58
Ph. Eur. edn. 6, test 2.9.15 or
(g/ml)
USP 31 <616>
Compressibility
11.3
18.9
Ph. Eur. edn. 6, 2.9.15 or
index (%)
USP 31 <616>
Flow rate (g/s)
17
No flow
Ph. Eur. edn. 6, 2.9.16 or
USP 31 <1174>
strength
600
600
N/A
Average weight
1022
1021
Ph. Eur. edn. 6, 2.9.5
(mg)
Thickness (mm)
5.7
6.2
The thickness of 10 tablets
was measured with a gauge
and the average determined.
Friability (%)
0.08
4 broken
Ph. Eur. edn. 6, 2.9.7 or USP
tablets
31 <1216>
Hardness (Kp)
27.5
9.9
Ph. Eur. edn. 6, 2.9.8 or USP
31 <1217>
Dissolution
81.5
67.9
Ph. Eur. edn. 6, 2.9.3 or USP
30′ (%)
31 <711>; the paddle
apparatus was used at 100 rpm
in pH 4.5
[0100] These results show the advantages gained by using wet rather than dry granulation, notably in the flowability, compressibility fields and tablet properties.
Effect of Binder Addition on Granule Characteristics on Lab Scale and on Industrial Scale
[0101]
[0000]
Lab-
Industrial
Batch
Lab-scale
Lab-scale
scale
Scale
methods
Binder adding
Dry
50% dry +
100%
50% dry +
N/A
technique
50%
dispersed
50%
dispersed
dispersed
Bulk density
0.53
0.54
0.54
0.61
Ph. Eur. edn. 6,
(g/ml)
2.9.15 or USP 31
<616>
Compressibility
6.2
6.7
7.1
6.3
Ph. Eur. edn. 6,
index (%)
2.9.15 or USP 31
<616>
Hausner ratio
1.18
1.15
1.17
1.13
Ph. Eur. edn. 6,
2.9.15 or USP 31
<616>
Flow rate (g/ml)
18.3
18.6
18.9
20.2
Ph. Eur. edn. 6,
2.9.16 or USP 31
<1174>
Porosity (%)
61.9
61.3
61.3
56.1
Bulk density was
([1 − (bulk
determined by Ph.
density/real
Eur. edn. 6, 2.9.15 or
density)] × 100)
USP 31 <616>; Real
density was
determined by Ph.
Eur. edn. 6, 2.9.23 or
USP 31 <699> (gas
pycnometry)
[0102] These results show that the method of addition of the binder, whilst not having a significant effect at laboratory scale, showed great improvements in both flowability and density at industrial scale.
[0103] Various modifications to the invention as described herein are within the scope of the invention. The skilled chemist will be aware of how to adjust the proportions of the excipients to achieve the results of the invention within the scope of the claims. While only certain embodiments have been described, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the appended claims. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments described specifically herein. Such equivalents are intended to be encompassed in the scope of the appended claims.
[0104] All references cited herein are hereby incorporated by reference herein in their entirety.
[0105] All technical and scientific terms used herein, unless otherwise defined below, are intended to have the same meaning as commonly understood by one of ordinary skill in the art. References to techniques employed herein are intended to refer to the techniques as commonly understood in the art, including variations on those techniques or substitutions of equivalent or later-developed techniques which would be apparent to one of skill in the art.
[0106] As used herein, the recitation of a numerical range is intended to convey that the embodiments may be practiced using any of the values within that range, including the bounds of the range. The variable can take multiple values in the range, including any sub-range of values within the cited range.
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A pharmaceutical composition comprising licarbazepine acetate, especially eslicarbazepine acetate, in combination with suitable excipients, in particular a binder, and a disintegrant. Also disclosed is a granulation process, especially a wet granulation process, for making the pharmaceutical composition.
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BACKGROUND OF THE INVENTION
This invention relates to a unit, particularly for floating point operations, having input and output devices which form the transition to data paths, control devices and devices for the simultaneous processing of data words, or parts of a data word, which represent characters and numbers with different arithmetic meanings.
A floating point unit (FPU) for carrying out floating point calculations within a data processing system is known from DE-OS (German Offenlegungsschrift) No. 29 49 375. It has a mantissa device, an exponent/sign device and a control device for controlling the mantissa device and the exponent/sign device. The mantissa device treats the mantissa parts of certain data in a first predetermined manner, the exponent/sign device treats, in a second predetermined manner, other data received by the mantissa device, and the control device allows the simultaneous activity of the mantissa device and the exponent/sign device. Concurrently or simultaneously carrying out mantissa operations and exponent/sign operations naturally results in an increased total efficiency. With the clock frequencies or cycle times used in these operations, a total of approximately 1100 ns are required for the individual states and functions during a floating point operation. The multitude of electronic components from which this known floating point unit is constructed also includes a shift register. This is constructed as a hexadecimal shift device and contains, in three columns and five lines, a total of 15 modules, which, however, are to be seen functionally as a single chain.
A rapid shift network which has a mask generator and cycling facility, and which is also intended for floating point arithmetic, is known from DE-OS (German Offenlegungsschrift) No. 27 45 451. Right-justified or left-justified shifts, which can be achieved by a sequence of single shifts and logic operations, can be more rapidly effected if networks which essentially function as shift registers, with the insertion of the correct number of characters to be filled in (zeros and ones), are used. In the case of the known shift network mentioned here, the basic shift function is broken down into two sub-functions--the rotation or cyclic shift and the production of a mask vector. These measures favorably affect the operational speed, the structure of the network with basic function blocks, and the control of the functions. The cycling unit provided for rotation shifts a basic data word cyclically by a number of digits which is prescribed by a shift-amount control word. The mask generator produces mask vectors, for example an array of zeros, the length of which is also determined by the shift-amount control word and which is followed by a series of ones (right-justified shift). Both processes are carried out in parallel. The number of output lines of the mask generator is equal to that power of two the exponent of which is equal to the number of input address lines. In the production of integrated circuits, the number of connecting pins or contacts is of substantial importance, so that mask generators as integrated circuits (IC) for these reasons can have between three and five input address lines, at the present state of technology.
In addition, 8-bit shift units are commercially available as integrated circuits, for example from the Signetics firm with the designation 8243 (Signetics Data Book, 1974, pages 3-28 to 3-32), it being possible to control the shift units by means of a 3-bit binary selection code. The advantage of shift units of this type in comparison with simple shift registers consists, on the one hand, in a higher speed and, in addition, in a low requirement of external logic elements. No clock pulses are necessary for the approximately 70 gate functions of a shift unit of this type, The speed is therefore only dependent on the circuit speed. These shift units can also be extended, for example by connecting together two modules of the type having 8 bits at the input and 16 bits at the output. For further extensions, however, the connections become very complex. In order to be able to shift in both directions, shift units of this type must be provided for each direction.
So-called "octal inverter buffers" with tri-state outputs are also commercially available as integrated logic circuits (see, for example, Valvo handbook "Signetics Integrated Logic Circuits 1978-79", pages 374/375, type 54/74, Series "240"). They mainly serve to switch signals through, without feedback, from several sources to an information sink, and have for this purpose several tri-state elements, for example four in each case, which can be conjointly activated and the outputs of which indicate the signals H or L (high/low) or a very high resistance.
The invention assumes that, because of the technological possibilities for carrying out frequently required arithmetic operations with appropriately constructed circuits, the use in computers of modules or arithmetic units with circuits of this type is becoming increasingly economical. In this context, the speed as well as the number and the variety of the functions required in such circuits are of considerable importance. The frequently required arithmetic operations include, in particular, the shifting of numeric words, for example in floating point operations.
SUMMARY OF THE INVENTION
It is, therefore, the object of the present invention to provide a shifter unit, particularly for floating point operations, in which, independently of the number of digits, all shifts can be carried out with one and the same high speed, and which essentially contains--that is to say, in the shift array and for the input and output units--only one type of logic elements, i.e. tri-state elements.
To attain this object the present invention provides a unit, particularly for floating point operations, having input and output devices which form the transition to data paths, control devices and devices for the simultaneous processing of data words, or parts of a data word, which represent characters and numbers with different arithmetic meanings, which comprises a shift array for n-digit numeric words, which is constructed from tri-state elements and contains in total, in n lines and n columns, a number n(n+1)/2 of elements of this type with which, by means of one particular control signal from a total of n control signals, the n inputs of the shift array, which are assigned to the individual digits of the numeric words, can be switched through, shifted by a particular number of positions, to the n outputs of the shift array; a read and output device, constructed from tri-state elements and connected to data paths, for the shift array having at least n such elements for the n-digit numeric words, and a control unit with a decoder, which converts a source record into an n-digit object record, of which the individual characters form the control signals to be fed to the shift array.
For a more exact explanation of the construction and function of the arithmetic unit according to the invention, the shift array is first explained more closely. The object of this shift array, for example, consists in representing a binary numeric word with n digits in such a manner that the most significant bit (MSB-first one of the digit sequence) appears left-justified or right-justified. For the n digits in the numeric word, there are n possibilities for the MSB. These n possibilities are accounted for, independently of the actual position of the MSB, in lines of the array which are each shifted, from line to line, by one digit. This gives a triangular matrix, since, on shifting the lines, the positions which become free at the end of the least significant bit (LSB-last one of the digit sequence) do not have to be occupied, and the positions which are not required at the end of the MSB do not have to be replaced. The numeric word appears at the output in the desired shifted representation when the line of the array which relates to the true position of the MSB is read and thereby the characters to be filled in at the LSB end appear as a sequence of identical digits (zeros/ones). This means that the signal inputs of the array lead for the MSB in the first position only to one tri-state element which is located in the first line and the first column; for the MSB in the second position, to two tri-state elements which are situated in the first line/second column and the second line/first column, etc., until for the MSB in the last position (nth position) they lead to n tri-state elements in the first line/nth column, second line/(n-1)th column, etc., until the nth line/first column. The signal outputs of the tri-state elements of each column are collected together, as are the control signal inputs of all tri-state elements of a particular line. The principle of the construction of such a matrix remains equivalent in its function if, with respect to the signal inputs, signal outputs and control signal inputs, the directions of the chain-like interconnections are interchanged.
It is, of course, also possible with such a shift array to shift an input numeric word by a desired number of digits, also independently of the position of the MSB. The shift of a binary numeric word corresponds, according to the direction of the shift, to a multiplication or a division by powers of two. It can easily be seen from this that such a shift array is advantageous not only for floating point operations.
Since the shift array essential for the invention has no logic elements for the omitted positions, but zeros must appear in the output, it must be ensured that the third, high-impedance state of the tri-state elements yields such zeros. For this purpose, the output unit which is constructed from tri-state elements and has a control signal OC is used for accepting the numeric word. An appropriately constructed device is also used for decoupling, too.
The control device, with which it is established, and by logic decisions fixed, at which numerical value of the numeric word located at the input of the array which line of the array is to be read, is also of substantial importance for the invention. In this context, it is intended, firstly, to make a short examination of the basics of floating point and fixed point calculations.
In the fixed point representation, a number is indicated by a single numeric word, in which each digit, with respect to its position as well as through its value, makes its contribution. If the base point is located, for example, at the end of the LSB, that is to say, the numeric character with the least significance, the significances of all positions are greater than or equal to one, and the numeric word represents an integer. In contrast, if the base point is located at the end of the MSB, that is to say, the numeric character with the highest significance, the numeric word represents a number which is smaller than one, and is thus a real fraction.
In the floating point representation, a data word, which contains two numeric words, is used for the numerical representation, in particular, for the number x to be represented, the mantissa M of which and the exponent E of which correspond to the formula:
x=±M·b.sup.±E,
wherein the number b, the floating point base, is a positive integer and need not be explicitly represented, if--as is customary--its value on the basis of the agreed convention is always the same. In these cases, the number x can be an integer or non-integral, positive or negative. Defined digits in the data word, mostly before the relevant numeric word, are therefore provided, if desired, for the signs of the exponent and also of the mantissa. The effort for the individual arithmetic operations (addition, subtraction, multiplication and division) is variable. In fixed point representation, many operations, for example with short numeric words, are more easily realizable. For example, for the addition of two numbers in floating point representation, both addends must have the same exponent E. The number of digits by which a mantissa is to be shifted follows from a comparison of the exponents. The result has to be normalized, if appropriate, that is to say, the mantissa has to be shifted so that the MSB is located in the first position, and the exponent must be correspondingly corrected. This type of shift of a mantissa is thus necessary before the actual arithmetic operation, and in the case of normalization or in the case of overflow of the result. Most of the execution time is spent in comparison of the exponents, in generating logic decisions and in shifting.
In the embodiments of the invention, the control device is responsible for the evaluation of the exponents and the generation of logic decisions, and enables these steps to be carried out in a very short throughput time. In this connection, the decoder is of considerable importance, the output signals of the decoder representing the control signals to be fed to the shift unit. It has, for example in the case of 4-bit numeric words, only to give at the allotted output, from the 2 4 =16 possibilities for exponents of the base 2, the position corresponding to the value of the exponent. These outputs of the decoder are each firmly associated, with respect to the control signals, with one line of the shift array. It is therefore ensured that always only the one relevant line is selected and can be read.
Shift processes of this type are necessary not only in calculations in floating point representation. As already mentioned above, multiplications/divisions can be carried out in this manner in fixed point representation, with powers of two. In addition, fixed point/floating point transformations or conversions are of particular importance, since data to be processed is often present in fixed point representation. For example, floating point/fixed point transformations are to be carried out by means of shift operations if data (after an arithmetic operation in floating point representation) is to be output via a digital/analog converter.
In a preferred embodiment of the invention the input and output units are equipped with additional tri-state elements which are assigned to a position representing a sign (plus/minus) in the data word. This is the sign of a numeric word in fixed point representation or a numeric word for the mantissa in floating point representation, which does not change in shift operations and can therefore be taken outside the lines and columns of the shift array.
An embodiment of the invention in which the input and output units each consist of two records of n tri-state elements each and accept an n-digit numeric word in mirror-image representations to each other in each case, is particularly preferred. This implies that a numeric word with, for example, a left-justified MSB is accepted by the input unit in this representation as well as mirrored, that is to say, with a right-justified MSB. If, owing to the arrangement of the tri-state elements in the triangular matrix, the shift array for example only carries out left shifts, but is fed with the numeric word to be shifted having a right-justified MSB instead of a left-justified MSB, the left shift of the mirrored numeric word and a repeated mirroring, now of the shifted numeric word in the output unit, is equivalent to a right shift. For shifts in both directions, only a single configuration, further still only a single shift array, is necessary with input and output devices of this type. The direction of the shift is without any significance with respect to the sign of a numeric word to be shifted to the left or to the right. Only a single set of tri-state elements for sign data is thus required in the input or output unit. However, a small difference in comparison with a non-mirroring output unit with respect to the sign signal consists in the fact that two tri-state elements are to be provided for reading out the sign, which elements are connected in parallel with respect to the signals, and the inputs of which lead to the signal output of the sign tri-state element of the input device, but with respect to the control signals are separately connected for "left shifts" or "right shifts" with the appropriate tri-state elements for the characters of the numeric words.
With respect to the construction of parts of the embodiments according to the invention as integrated circuits, it is very expedient if the tri-state elements for the shift array and for the input and output units are contained there in one module. For 8-bit data words such a module would require a total of 24 pins, or connecting lugs, for the signal inputs and signal outputs and for the control signals, so that--including the lugs for the power supply--commercial sizes result in this case.
If data words which are longer than 8-bits are to be processed, the number of control signal inputs can be reduced on including in the integrated circuit the decoder assigned to the control device, according to a further preferred embodiment of the invention. Without going more deeply here into the technological questions concerning the integratability, it may only be further mentioned that a further increase is possible with an alternating use of the connecting lugs for the input and the output signals. On the other hand, the fact that in embodiments of the invention--in contrast, for example, to multiplexers, which are used for such purposes in the hitherto known state of the art--the outlay for higher precision of arithmetic operations, that is to say for greater word lengths of the numeric words to be processed, does not increase disproportionately, and the word length has no effect at all with respect to the processing time.
The universal applicability of the embodiments of the invention allows or requires special forms of the control devices for specific arithmetic operations. For this purpose, among the multitude of uses of shift operations, in particular the possibilities of transformation of fixed point representation into floating point representation and vice versa are of considerable importance for the invention. For the fixed point/floating point conversion, the control device can preferably have a PAL (programmable array logic) module, the outputs of which yield a source record for the decoder and a result for a numeric word representing an exponent. It is therefore possible, during a single step, on the one hand to establish the position of the MSB in a numeric word in fixed point representation from which the associated number of positions by which the numeric word is to be shifted follows, and to give the value of the exponent numeric word for the floating point representation, as well as--during the same step--to carry out the shift of the numeric word, that is to say, to remove from the shift array the numeric word shifted by the appropriate number of positions.
A floating point/fixed point conversion can be carried out in a similar manner, and just as surprisingly simply, if the control device has an inverter for a numeric word which represents a source record for the decoder. In this process, likewise during a single step, the part of the data word corresponding to the exponent is fed, on the one hand, from the data word which is to be converted and which is present in floating point representation, to the inverter which inverts the characters of the exponent numeric word as a source record for the decoder, whilst on the other hand the part of the data word corresponding to the mantissa comes in mirrored form into the shift array, from which, corresponding to the source record of the inverter, the appropriate line is selected via the decoder, the result of this line is mirrored and thus gives the numeric word in fixed point representation.
BRIEF DESCRIPTION OF THE DRAWINGS
Some preferred embodiments of the invention will now be described by way of example and with reference to the accompanying schematic drawings in which:
FIG. 1 shows a shift array, constructed with tri-state elements, for an 8-bit data word;
FIG. 2 shows a table for the description of the state of the shift array according to FIG. 1;
FIG. 3 shows a shift array, corresponding to FIG. 1, constructed with tri-state elements, but for an n-bit data word;
FIG. 4 shows a processing unit consisting of a shift array and of input and output devices which are constructed with tri-state elements;
FIG. 5 is a block diagram for a fixed point/floating point converter, and
FIG. 6 is a block diagram for a floating point/fixed point converter.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The shift array shown in FIG. 1 is arranged for an 8-bit data word. In this figure, the data inputs D0, D1, . . . , D6 are provided for seven digits of a numeric word, and the position D7 for the sign of this numeric word. Input data from D0 reach one tri-state element in each line and each column of the shift array, the position of D0 being pulled or shifted to the left, line by line from top to bottom, by one position in each case. Correspondingly, input data from D1 reaches the penultimate line of the shift array, and so on, until position D6, for which only a single tri-state element is located in the uppermost line and the left-hand column. The data outputs Y in the output unit, a further line with eight tri-state elements outside the actual shift array, collect together by columns the signal outputs of the tri-state elements of the shift array, a single connection with the tri-state element for D7 at the data input existing for the data output Y7, the sign. The control signal inputs S0, . . . , S6 for the tri-state elements of the shift array are collected together by lines, so that, with the control signals, that line can be selected from which the input data, shifted to the left by the appropriate number of positions, can be read out. For this purpose, the output line is opened with the control signal OC.
In the activated state, the tri-state elements allow the signal located at the input, a one or a zero, to pass through to the output, and, in the non-activated state, the tri-state elements show a very high resistance at the output, which effects a decoupling. Circuits of this type with a so-called tri-state output are known as such in many electronic components, but are used in the embodiments of the invention, preferably in the form of inverting tri-state elements, as electronic switches or electronic crosspoints in a switching network.
The mode of operation of the shift array according to FIG. 1 can be seen from the table given in FIG. 2. If no line of the shift array is activated, that is to say (S6, . . . , S0)=X, and if the output line is also not opened, that is to say, OC=1, the very high resistances appear at all the data outputs (Y7, . . . , Y0)=Z, instead of the signals. The following lines of the table indicate which input data D0, . . . , D7 appear at the outputs Y0, . . . , Y7 if one of the lines is selected and the output line is opened (Si=0, OC=0), or, in the last line of the table, if no line of the shift array is chosen (S0, . . . , S6)=1.
The shift array represented in FIG. 3 differs from that according to FIG. 1 only in size. It can be seen that the principle of construction is the same, and, by a simple extension of the lines and columns of the array, shift operations can be carried out with numeric words having relatively long mantissas. For n-digit numeric words, the shift array contains in n lines and n columns--not including the tri-state elements for signs and for the output unit or output line--a total of n(n+1)/2 elements of this type.
A processing unit, as shown in FIG. 4, consists of the shift array--now no longer represented in detail here--and of input and output devices, which are constructed from tri-state elements. The special feature of this processing unit consists in being able to carry out left shifts as well as right shifts with the unit, although the shift array is only designed for one direction. The input device consists of two sets of tri-state elements, in which the data inputs of one tri-state element of each of the two sets are connected in parallel. The individual digits of an input numeric word therefore enter the two sets completely identically. The data outputs of one tri-state element of each of the two sets are, however, combined in reverse with respect to the positions:
Position N-2 of the left set with position 0 of the right set,
Position N-3 of the left set with position 1 of the right set,
Position N-4 of the left set with position 2 of the right set,
and so on
until
Position 0 of the left set with position N-2 of the right set.
The position N-1 is meant for the sign of the numeric word, and does not participate in the mirroring. By means of the control signals L or R for the input device, it can be determined whether the numeric word is to be fed to the shift array in its original position or mirrored. The output unit is identical in its construction with the input unit, except for a trivial difference in the position N-1 for the sign, which is explained immediately below. The shifted numeric word is thereby also available at the data outputs Y0, . . . ,Y(N-2)-relative to the output of the shift array-in the original position or mirrored. In other words, this has the following meaning: owing to its construction, left-justified positions are rejected in each case from the shift array, and, in place of these, digits are inserted from the right. However, if a shift is required in which right-justified digits are to be omitted, and, correspondingly digits are to be inserted from the left, the particular numeric word is shifted in its mirrored representation and is then again mirrored.
The sign of the numeric word is retained in the operations described. It has therefore to be given at the position Y(N-1) at the data output in exactly the form in which it appears at the data input D(N-1). Since two variants are available for opening the output unit, one tri-state element for the sign signal must also be provided for each of these two variants. These are connected in parallel, with respect to the signal, at the input and at the output, and are directly connected with the data output of the tri-state element of the input unit.
FIG. 5 shows a fixed point/floating point converter in principle, but, at the same time, with an example given in this figure for an operation of this type. A 16-bit data word, the left-justified position of which has a character 0 for the -positive- sign of the decimal number 294 in fixed point representation, reaches this arithmetic unit via the data path. The positions associated with the binary number are: 000000100100110. (That is: 2 8 +2 5 +2 2 +2 1 =294=2 9 (1/2+1/16+1/128+1/256).)
The binary number enters the shift array, where the positions are shifted progressively from line to line by one digit to the left in each case. The PAL (programmable logic array) module, to which the data word is simultaneously fed, establishes that there are six zeros before the MSB (most significant bit) of the numeric word. It concludes therefrom, on the one hand, that the number to be given in floating point representation must be smaller than 2 9 , since, for a total of 15 positions minus 6 zero position from the left, the following results for the exponent of the number two: 15-6=9; (2 9 =512). On the other hand, it gives the number 6 as the source record, in the form 0110, to the decoder, which, taking this source record and using the "1 from 16" generated code, selects that line, in the shift array, in which the first six positions from the left are rejected. This is the ninth line from the bottom. The following thus appear as the result:
______________________________________ Mantissa: sign: 0 (= positive) numeric word: 100100110000000 Exponent: sign: 0 (= positive) numeric word: 1001 As can easily be calculated, 294 = 2.sup.9 · 0.57421875, wherein the mantissa is composed of:1/2 = 0.51/16 = 0.06251/128 = 0.00781251/256 = 0.00390625 0.57421875______________________________________
The execution time for this fixed point/floating point conversion is approximately 40 ns, approximately 25 ns being associated with the operation in the PAL module.
FIG. 6 shows, similarly to FIG. 5, an arithmetic unit, in this case, however, for a floating point/fixed point conversion. The shift array and the decoder are identical with those according to FIG. 5. For the example chosen in FIG. 6, the same numbers are employed as in the example for FIG. 5, for the sake of simplicity. The number present in floating point representation is represented by the 21-bit data word, of which the left-justified digit contains the character for the sign of the exponent, the digits 2 to 5 contain the numeric word for the exponent, the digit 6 contains the character for the sign of the mantissa and the remaining positions contain the numeric word for the mantissa.
The signs of the exponent and of the mantissa remain unchanged in the floating point/fixed point conversion. The numeric word for the mantissa has its MSB position left-justified and cannot therefore be directly fed, for a shift operation, to the shift array, which, owing to its configuration, rejects left-justified positions and inserts digits from the right. The numeric word is therefore fed in mirrored representation to the shift array, this representation being symbolized by the twisted arrow in the input unit. This mirrored numeric word is now retained in readiness in the shift array, in the manner already described, in the individual lines displaced by one--further--position in each case. The choice of the relevant line of the shift array is effected by the decoder, again in the manner already described in connection with FIG. 5.
For this purpose, the formulation of the source record for the decoder from the numeric word of the exponent is required, which formulation is effected in a surprisingly simple manner in the embodiment described here. In order to be able to use the same decoder which is also employed in the other operations, the characters of the exponent numeric word have only to be inverted that is, complemented, and thus form the source record for the decoder.
In the example considered, the ninth line from the bottom in the shift array is thereby selected by the decoder. The binary number abstracted from this line is mirrored, which operation is again symbolized by the twisted arrow in the output unit. The result of this is the fixed point representation of the numeric word.
The execution time for this floating point/fixed point conversion, in this case also in one step, is approximately 30 ns.
The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The embodiments are therefore to be considered in all respects as illustrative and not restrictive.
A report on the invention described in this text was also given within the framework of the "IEEE 1980 International Conference on Circuits and Computers (ICCC) for Large Scale Systems" from Oct. 1-3, 1980 (Architecture for VLSI Circuits in Digital Signal Processing; authors: Block, R., Botcher, K., Lacroix, A. and Talmi, M.).
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An arithmetic unit, particularly for floating point operations, is provided in which numeric words with n digits, shifted by any desired number of digits, can be taken, in one step with a duration independent of the extent of the shift, from a shift array which is constructed from tri-state elements in a triangular matrix.
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STATEMENT OF GOVERNMENT INTEREST
The inventions described herein may be manufactured, used and licensed by or for the U.S. Government for U.S. Government purposes.
BACKGROUND OF THE INVENTION
The invention relates in general to wells and in particular to initiating flow from a well.
To initiate the flow of oil and/or other materials in a well, a conventional shaped charge warhead (or perforator) is fired through the well casing, the cement sheath and into the earthen formation. A shaped charge device comprises a shaped charge liner backed by high explosives. When the explosives are detonated, the shaped charge device forms a high velocity forward moving penetrator or “jet” that is capable of deeply penetrating the targeted material.
Output of a well is dependent on several factors including the size of the hole made by the perforator, the hole shape and the penetration depth. Fracturing fluids are pumped into the hole to fracture the rock formation and special agents in the fluid hold the fractures open to allow flow. Small diameter holes (as produced by conventional shaped charges) have a tendency to clog with these agents. Well and rock conditions vary at different depths in the same well and in different wells, due to geological differences.
A variety of perforators are available for different applications. A disadvantage of conventional perforators is they can only produce one jet profile per design. A single perforator lacks the ability to handle varying well and rock conditions. Most available perforators are designed to produce deep penetration but with a very small diameter hole. To change the jet output and, therefore, the hole profile, a different perforator is required for each desired hole profile.
At present, a variety of perforators must be on hand to handle different situations. U.S. Pat. No. 6,925,924 issued on Aug. 9, 2005 and is incorporated by reference herein. The '924 patent shows shaped charge perforators with multiple initiation points. These perforators can produce different jets. However, each perforator is limited to producing a single jet profile. Thus, a need exists for a single perforator that can selectively produce varying jet outputs for different applications.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an apparatus and method for selectively producing different types of perforations in well bores.
A first aspect of the invention is a shaped charge comprising a case having an open front end, a closed rear end, an interior and a longitudinal axis; an explosive material disposed in the interior of the case; and a liner disposed over the explosive material; wherein the case includes a first channel extending from an opening on the rear end of the case along the longitudinal axis to an opening in the interior of the case adjacent the explosive material; and a pair of second channels, the pair of second channels having a common opening on the rear end of the case, the common opening being a different opening than the opening for the first channel, the pair of second channels ending in a pair of diametrically opposed openings in the interior of the case adjacent the explosive material, the pair of openings being disposed on opposite sides of the opening of the first channel.
The shaped charge may further comprise a pair of third channels, the pair of third channels having a common opening on the rear end of the case, the common opening for the third channels being a different opening than the opening for the first channel and the common opening for the second channels, the pair of third channels ending in a pair of diametrically opposed openings in the interior of the case adjacent the explosive material, the pair of openings being disposed on opposite sides of the interior case opening of the first channel and further forward than the pair of interior case openings for the second channels.
A second aspect of the invention is a method comprising providing a shaped charge according to the first aspect of the invention; and detonating the shaped charge using only one of 1) the opening on the rear end of the case for the first channel; 2) the common opening on the rear end of the case for the second channels; and 3) the common opening on the rear end of the case for the third channels.
A third aspect of the invention is a shaped charge comprising a case having an open front end, a closed rear end, an interior and a longitudinal axis; an explosive material disposed in the interior of the case; and a liner disposed over the explosive material; wherein the case includes four channels extending from a common opening on the rear end of the case to four diametrically opposed openings in the interior of the case adjacent the explosive material.
The shaped charge may further comprise a fifth channel extending from an opening on the rear end of the case to an opening in the interior of the case adjacent the explosive material, the opening on the rear end of the case being a different opening than the common opening for the four channels, the opening in the interior of the case being centered on the longitudinal axis.
A fourth aspect of the invention is a method comprising providing a shaped charge according to the third aspect of the invention; and detonating the shaped charge using only one of the common opening on the rear end of the case for the four channels and the opening on the rear end of the case for the fifth channel.
A fifth aspect of the invention is a shaped charge comprising a case having an open front end, a closed rear end, an interior and a longitudinal axis; an explosive material disposed in the interior of the case; and a liner disposed over the explosive material; wherein the case includes a first channel extending from an opening on the rear end of the case along the longitudinal axis to an interior opening in the interior of the case adjacent the explosive material; and a pair of second channels extending from a pair of openings on the rear end of the case to a pair of diametrically opposed interior openings in the interior of the case adjacent the explosive material, the pair of diametrically opposed interior openings of the second channels being disposed on opposite sides of the first channel.
The shaped charge may further comprise a pair of third channels extending from a pair of openings on the rear end of the case to a pair of diametrically opposed interior openings in the interior of the case adjacent the explosive material, the pair of diametrically opposed interior openings of the third channels being disposed on opposite sides of the interior opening of the first channel and radially outward from the pair of interior openings of the second channels.
The shaped charge may additionally comprise a pair of fourth channels extending from a pair of openings on the rear end of the case to a pair of diametrically opposed interior openings in the interior of the case adjacent the explosive material, the pair of diametrically opposed interior openings of the fourth channels being disposed on opposite sides of the interior opening of the first channel, radially outward from the pair of interior openings of the third channels and axially forward from the pair of interior openings of the third channels.
Advantageously, the shaped charge further comprises a pair of fifth channels extending from a pair of openings on the rear end of the case to a pair of diametrically opposed interior openings in the interior of the case adjacent the explosive material, the pair of interior openings for the fifth channels being disposed on opposite sides of the interior opening of the first channel, radially outward from the pair of interior openings of the fourth channels and axially forward from the pair of interior openings of the fourth channels.
In one embodiment of the fifth aspect of the invention, the shaped charge further comprises a pair of sixth channels extending from a pair of openings on the rear end of the case to a pair of diametrically opposed interior openings in the interior of the case adjacent the explosive material, the pair of interior openings of the sixth channels being disposed on opposite sides of the interior opening of the first channel, offset circumferentially about ninety degrees from the interior openings of the second pair of channels and disposed radially outward from the interior opening of the first channel about a same distance as the interior openings for the second pair of channels.
A sixth aspect of the invention is a method comprising providing the shaped charge of fifth aspect of the invention; and detonating the shaped charge using at least one of the first channel, the pair of second channels, the pair of third channels, the pair of fourth channels, the pair of fifth channels and the pair of sixth channels. The detonating step may include using only one of the first channel, the pair of second channels, the pair of third channels, the pair of fourth channels, the pair of fifth channels and the pairs of second and sixth channels.
A seventh aspect of the invention is a method comprising providing a shaped charge having a case having an open front end, a closed rear end, an interior and a longitudinal axis; an explosive material disposed in the interior of the case; and a liner disposed over the explosive material; the shaped charge including a plurality of channels formed therein extending from the rear end to the interior adjacent the explosive material; and detonating the shaped charge using at least one, but not all, of the plurality of channels.
The invention will be better understood, and further objects, features, and advantages thereof will become more apparent from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, which are not necessarily to scale, like or corresponding parts are denoted by like or corresponding reference numerals.
FIG. 1A is a rear view of one embodiment of a shaped charge.
FIG. 1B is a sectional view along the line 1 B- 1 B of FIG. 1A .
FIGS. 1C and 1D are modified sectional views of FIG. 1A .
FIG. 2A is a rear view of another embodiment of a shaped charge.
FIG. 2B is a sectional view along the line 2 B- 2 B of FIG. 2A .
FIGS. 2C and 2D are modified sectional views of FIG. 2A .
FIG. 3A is a rear view of another embodiment of a shaped charge.
FIG. 3B is a sectional view along the line 3 B- 3 B of FIG. 3A .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Shaped charges that produce a long and narrow jet by axial initiation will produce a fan-like jet if two diametrically opposed detonators are initiated along the side of the warhead. As the detonation points are moved forward along the warhead, the jet output changes. Single point initiation produces a long thin jet for deep penetration. Moving multiple detonation points slightly forward produces a narrow fan-shaped jet followed by a foreshortened round jet. Moving the detonation points even further forward produces a wide fan-shaped jet.
The use of four detonation points can produce a variety of effects depending on initiation locations. These locations usually involve a tradeoff between hole depth and hole cross-sectional area. The present invention is a selectable output, shaped charge perforator that can produce various jet profiles. Thus, one perforator may be used to produce jet patterns that can vary depending on well and rock conditions. Multiple sets of dual diametrically-opposed detonation points (or quad detonation points) are included in the shaped charge case to allow for selection of the required jet profile to match required conditions.
Commercial well perforators generally use detonation cord (det cord) as the initiation mechanism. In the invention, multiple detonation tracks are fabricated in the shaped charge case to allow selective initiation by choice of det cord placement, or, by rotating or indexing the perforator in its holding fixture. Dual (two point) or quad (four point) initiation may be accomplished from a common point or from multiple points.
FIG. 1A is a rear view of one embodiment of a shaped charge 10 . FIG. 1B is a sectional view along the line 1 B- 1 B of FIG. 1A . Shaped charge 10 includes a case 12 having an open front end 14 , a closed rear end 16 , an interior and a longitudinal axis X-X. An explosive material 18 is disposed in the interior of the case 12 . A liner 20 is disposed over the explosive material 18 . In FIG. 1A , the dotted lines represent channels within the case 12 and openings into the interior of the case 12 . FIGS. 1C and 1D are modified sectional views of FIG. 1A . In FIGS. 1C and 1D , only one pair of channels are shown. For purposes of clarity, FIGS. 1C and 1D are planar projections of the channels 38 , 40 and 28 , 30 , respectively.
Case 12 includes a first channel 22 extending from an opening 24 on the rear end of the case along the longitudinal axis X-X to an opening 26 in the interior of the case adjacent the explosive material. A pair of second channels 28 , 30 have a common opening 32 on the rear end of the case. The common opening 32 is a different opening than the opening 24 for the first channel 22 . The pair of second channels 28 , 30 end in a pair of diametrically opposed openings 34 , 36 in the interior of the case adjacent the explosive material. The pair of openings 34 , 36 are disposed on opposite sides of the opening 26 of the first channel 22 . Preferably, the pair of openings 34 , 36 are about a same distance from the interior case opening 26 for the first channel 22 . More preferably, the pair of openings 34 , 36 and the interior case opening 26 for the first channel are substantially collinear.
Shaped charge 10 further comprises a pair of third channels 38 , 40 . The pair of third channels 38 , 40 having a common opening 42 on the rear end of the case 12 . The common opening 42 for the third channels is a different opening than the opening 24 for the first channel and the common opening 32 for the second channels. The pair of third channels 38 , 40 end in a pair of diametrically opposed openings 44 , 46 in the interior of the case adjacent the explosive material. The pair of openings 44 , 46 are disposed on opposite sides of the interior case opening 26 of the first channel and located axially further forward than the pair of interior case openings 34 , 36 for the second channels 28 , 30 . Preferably, the pair of interior case openings 34 , 36 for the third channels are about a same distance from the interior case opening 26 for the first channel. More preferably, the pair of interior case openings 34 , 36 for the third channel and the interior case opening 26 for the first channel are substantially collinear.
FIG. 2A is a rear view of another embodiment of a shaped charge 50 . FIG. 2B is a sectional view along the line 2 B- 2 B of FIG. 2A . Shaped charge 50 comprises a case 52 having an open front end 54 , a closed rear end 56 , an interior and a longitudinal axis X-X. Explosive material 58 is disposed in the interior of the case 52 . A liner 60 is disposed over the explosive material 58 . In FIG. 2A , the dotted lines represent channels within the case 52 and openings into the interior of the case 52 . FIGS. 2C and 2D are modified sectional views of FIG. 2A . For purposes of clarity, FIGS. 2C and 2D are planar projections of the channels 62 - 68 and 80 , respectively.
Case 52 includes four channels 62 , 64 , 66 , 68 extending from a common opening 70 on the rear end of the case to four diametrically opposed openings 72 , 74 , 76 , 78 in the interior of the case adjacent the explosive material. The common opening 70 on the rear end of the case may be centered on the longitudinal axis X-X. The four openings 72 - 78 in the interior of the case are circumferentially spaced about 90 degrees apart and are equidistant from the longitudinal axis X-X.
Case 52 further comprises a fifth channel 80 extending from an opening 82 on the rear end of the case to an opening 84 in the interior of the case adjacent the explosive material. The opening 82 on the rear end of the case is a different opening than the common opening 70 for the four channels 62 - 68 . The opening 84 in the interior of the case is centered on the longitudinal axis X-X.
In shaped charges 10 and 50 , each set of channels begins at a common initiation point on the rear end of the case and then forms single or multiple detonation paths to the main explosive in the case. The channels in the case may be filled with an explosive or detonation cord. The desired jet output is produced by selecting and initiating only one of the openings in the rear of the case. One way to do this is to place det cord over the selected openings. As used herein, the “rear” or “rear end” of the case is broadly defined as any portion of the case that is to the rear of the open front end. Thus, the “rear” or “rear end” of the case includes side walls that may be angled, horizontal or curved.
In shaped charge 10 , det cord placed only on opening 24 produces a conventional axisymmetric jet for deep penetration. Det cord placed only on opening 32 produces a fan-shaped jet. Det cord placed only on opening 42 produces a wider fan-shaped jet, because the interior openings associated with opening 42 are further forward axially than the interior openings associated with opening 32 . In shaped charge 50 , det cord placed only on opening 82 produces a conventional axisymmetric jet for deep penetration. Det cord placed only on opening 70 produces a cross-shaped or plus sign shaped jet.
FIG. 3A is a rear view of another embodiment of a shaped charge 90 . FIG. 3B is a sectional view along the line 3 B- 3 B of FIG. 3A . Shaped charge 90 comprises a case 92 having an open front end 94 , a closed rear end 96 , an interior and a longitudinal axis X-X. Explosive material 98 is disposed in the interior of the case 92 . A liner 100 is disposed over the explosive material 98 .
Case 92 includes a first channel 102 extending from an opening 104 on the rear end of the case 92 along the longitudinal axis X-X to an opening 106 in the interior of the case adjacent the explosive material. A pair of second channels 108 , 110 extend from a pair of openings 112 , 114 on the rear end of the case to a pair of diametrically opposed openings 116 , 118 in the interior of the case adjacent the explosive material. The pair of openings 116 , 118 are disposed on opposite sides of the opening 106 .
Shaped charge 90 further comprises a pair of third channels 120 , 122 extending from a pair of openings 124 , 126 on the rear end of the case to a pair of diametrically opposed openings 128 , 130 in the interior of the case adjacent the explosive material. The pair of openings 128 , 130 are disposed on opposite sides of the opening 106 , radially outward from the pair of openings 116 , 118 and axially forward of the openings 116 , 118 .
Additional pairs of channels may be added. Each additional pair of channels ends in diametrically opposed openings in the interior of the case that are radially outward of the preceding pair of interior openings and located axially further forward than the preceding pair of interior openings. For example, a pair of fourth channels 132 , 134 extends from a pair of openings 136 , 138 on the rear end of the case to a pair of diametrically opposed openings 140 , 142 in the interior of the case adjacent the explosive material. Openings 140 , 142 are disposed on opposite sides of the opening 106 , radially outward from the pair of openings 128 , 130 and axially forward of the openings 128 , 130 .
Similarly, a pair of fifth channels 144 , 146 extends from a pair of openings 148 , 150 on the rear end of the case to a pair of diametrically opposed openings 152 , 154 in the interior of the case adjacent the explosive material. Openings 152 , 154 are disposed on opposite sides of the opening 106 , radially outward from the openings 140 , 142 and axially forward of the openings 140 , 142 .
A pair of sixth channels 156 , 158 ( FIG. 3A ) extend from a pair of openings 160 , 162 on the rear end of the case to a pair of diametrically opposed openings (not shown) in the interior of the case adjacent the explosive material. The interior case openings of channels 156 , 158 have about the same radial and axial position as openings 118 , 116 , respectively, but are offset circumferentially about ninety degrees from the openings 118 , 116 .
It is the location of the interior openings of the various channels that determine where the explosive 98 will be initiated. Therefore, the precise location of the openings on the rear of the case and the position of the channels is not as important. Preferably, however, for ease of construction, all the channels are substantially parallel to the longitudinal axis X-X with the location of the openings on the rear of the case mirroring the location of the openings in the interior of the case.
In shaped charge 90 , each channel begins at an initiation point on the rear and of the case and then forms a single path to the main explosive in the case. The channels may be filled with an explosive or detonation cord. The desired jet output is produced by selecting and initiating certain openings in the rear of the case. One way to do this is to place det cord over the selected openings.
In shaped charge 90 , det cord placed on opening 104 produces a conventional axisymmetric jet for deep penetration. Det cord placed on openings 114 and 112 (or 160 and 162 ) produces a fan-shaped jet. Det cord placed on the four openings 114 , 112 , 160 and 162 produces a cross-shaped or plus sign shaped jet. Det cord placed on openings 124 and 126 produces a wider fan-shaped jet than openings 114 and 112 (or 160 and 162 ), because the diametrically opposed interior openings associated with openings 124 and 126 are further forward axially than the diametrically opposed interior openings associated with openings 114 and 112 (or 160 and 162 ). Likewise, det cord place on openings 136 and 138 produces a wider fan-shaped jet than openings 124 and 126 and det cord placed on openings 148 and 150 produces a wider fan-shaped jet than openings 136 and 138 .
While the invention has been described with reference to certain preferred embodiments, numerous changes, alterations and modifications to the described embodiments are possible without departing from the spirit and scope of the invention as defined in the appended claims, and equivalents thereof.
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Various shaped charges and methods of operation produce multiple jets in various profiles by employing multiple initiation points to address various earthen formations and producing different types of perforations in well bores. The shaped charge device includes a configuration of components wherein multiple detonation tracks are used to allow selective initiation and operation. Dual or quad initiation may be provided to initiate operation.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to plumbing installations, and more particularly, to boxes for use in attaching the water supply hoses and drain hose of a washing machine to corresponding boiler drain valves and a drain line mounted in a wall.
2. Description of the Related Art
Outwardly opening boxes have heretofore been mounted in a recessed fashion in a wall for providing a mounting fixture for a pair of boiler drain valves connected to hot and cold water supply lines in the wall. Such boxes have also typically been provided with a circular drain opening which is connected to a DWV drain pipe.
One common type of prior art washing machines outlet box typically includes a substantially rigid rectangular frame for being fixedly attached to two adjacent studs of the wall by way of ears and nails or the like. A first water valve is attached to the bottom of the frame adjacent one side wall thereof to allow a first water outlet and a first washing machine water hose to be attached thereto. A second valve is attached to the bottom of the frame adjacent the other side wall thereof to allow a second water outlet line and a second washing machine water hose to be attached thereto. A coupling member is attached to the bottom of the frame between the first and second water valves to allow a drain line and a washing machine drain hose to be attached thereto. The drain line includes a typical P-trap assembly. One problem with such prior art washing machine boxes is the requirement that one of the water outlet lines crosses over the P-trap assembly. Such cross overs are difficult and time consuming for the plumber and/or installer of the washing machine box, etc., and often prevent smooth installation of wall board or the like.
Another type of prior art washing machine outlet box also includes a substantially rigid rectangular frame for being fixedly attached to two adjacent studs of the wall by way of ears and nails or the like with a first water valve attached to the bottom of the frame adjacent one side thereof to allow a first water outlet line and a first washing machine hose to be attached thereto. However, the coupling member is attached to the bottom of the frame adjacent the other side wall and the second valve is attached to the bottom of the frame between the first water valve and the coupling member to allow a drain line and a washing machine drain hose to be attached to the frame adjacent one side wall thereof. One problem with such prior art washing machine boxes is the requirement that separate boxes be produced for installing the drain line and drain hose on the right or left of the water lines, etc.
In U.S. Pat. No. 4,716,925 of Prather there is disclosed a reversible side outlet washing machine box designed to overcome the problem mentioned in the previous paragraph. More specifically, the Prather patent discloses a washing machine outlet box having a reversible base member with means for allowing a first water valve to be connected to one end thereof, means for allowing a drain line to be attached to the other end thereof, and means for allowing a second water valve to be attached between the first water valve and the drain line.
U.S. Pat. No. 4,934,410 of Humber discloses a washing machine outlet box which allows hot and cold water boiler drain valves to be mounted in the center of the box regardless of whether the drain line if located to the left or to the right of the water supply lines.
U.S. Pat. Nos. 2,952,271 of Dick et al. and 4,410,004 of Kifer et al. disclose washing machine outlet boxes designed to accommodate electrical outlet boxes.
U.S. Pat. No. 4,069,837 of Jirasek discloses a washing machine outlet box incorporating a control unit connected to a pressure switch which senses a build-up of water pressure within the drain pipe to bring the electrical circuit to the washing machine.
Most washing machine outlet boxes which are currently in commercial production are made of injection molded plastic. There are many situations in which a washing machine outlet box needs to be installed in a fire wall, and in such cases, a metal washing machine outlet box must be utilized. Projects constructed for the U.S. Government typically require metal washing machine outlet boxes, including buildings constructed under the direction or supervision of the Department of Housing and Urban Development (HUD). Metal washing machine outlet boxes have heretofore been constructed of separate pieces of sheet metal which must be folded, assembled, soldered or welded, and then painted. Such metal washing machine outlet boxes have therefore been relatively expensive. It would therefore be desirable to provide a washing machine outlet box configuration which can be readily stamped from sheet metal to dramatically reduce the fabrication costs thereof. Preferably, the same washing machine outlet box configuration could also be injection molded from plastic for those installations not requiring a fireproof construction.
Washing machine outlet boxes heretofore commercially available have been relatively large. The wall in which a washing machine outlet box is typically installed is crowded with water supply lines, electrical lines, a drain line and a P-trap. In most washing machine outlet boxes, the boiler drain valves are mounted vertically. This makes it difficult to couple water supply lines which may extend downwardly in the wall from above the washing machine outlet box installation location. When the boiler drain valves are vertically oriented, it is often necessary for at least one of the water supply lines, when they extend horizontally, to cross over the drain pipe. This makes the installation more complex.
U.S. Pat. No. 4,564,249 of Logsdon discloses a so-called miniature washing machine outlet box which includes a drainpipe coupling with a tear-out disc which normally seals the opening for pressure testing. This washing machine outlet box still utilizes vertically oriented boiler drain valves and is intended for injection molded plastic construction. Therefore, it cannot be readily and inexpensively manufactured from metal. The embodiment of the Logsdon washing machine outlet box illustrated in FIGS. 7 and 8 of the Logsdon patent includes a single lever hot and cold water inlet valve. Brackets are attached to the side walls of the Logsdon washing machine outlet box to span the distance between adjacent wall studs and allow the washing machine outlet box to be nailed thereto.
SUMMARY OF THE INVENTION
It is therefore the primary object of the present invention to provide a compact, aesthetic washing machine outlet box which may be more easily connected to hot and cold water supply lines, washing machine supply hoses, and a drain line with a configuration that may be inexpensively stamped from sheet metal or injection molded of plastic.
Accordingly, the present invention provides a forwardly opening low profile washing machine outlet box configured so that it can be stamped as a unitary piece of sheet metal. The outlet box comprises a back wall having an upper vertical section and a lower downwardly extending forwardly sloping wall section, a forwardly extending peripheral wall integral with and extending forwardly from a peripheral edge of the back wall, first and second apertures in the upper vertical section for mounting first and second valve shanks for receiving first and second water supply lines, and an enlarged aperture in said lower wall section for connecting to a drain line and for receiving a washing machine drain hose.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects and advantages of the invention will become apparent from the following description when read in conjunction with the accompanying drawings wherein:
FIG. 1 is a is a front elevation view of a preferred embodiment of the invention mounted in a wall, with portions broken away to reveal details;
FIG. 2 is a vertical sectional view taken generally along line 2--2 of FIG. 1;
FIG. 3 is a horizontal sectional view taken along line 3--3 of FIG. 1; and
FIG. 4 is a partial vertical sectional view taken along line 4--4 of FIG. 2 with portions broken out showing details of the valve mounting holes.
FIG. 5 is a diagrammatic part horizontal sectional, part elevational view illustrating the installation of a conventional washing machine outlet box in accordance with the teachings of the prior art.
FIG. 6 is a diagrammatic top elevational view illustrating the installation of a compact washing machine outlet box in accordance with the present invention.
FIG. 7 is a diagrammatic rear elevational view of the installation of FIG. 5.
FIG. 8 is a diagrammatic rear elevational view of the installation of FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 of the drawings, a plumbing installation is illustrated including a forwardly opening low profile washing machine outlet box designated generally by the numeral 10 which mounts hot and cold water valves for connection and supply of hot and cold water to a washing machine and for accommodating an outlet drain. The box 10 is preferably constructed of sheet metal in a stamping or drawing process, although it may be molded of a suitable plastic as a single unitary piece. The stamping or drawing process is a well-known process using a progressive die and will not be described here in detail. The box 10 is thus preferably formed as a unitary sheet metal stamping. The corners may have a one inch radius.
The box 10 is formed with an upper generally planar vertical back wall section 14 connected to a lower forwardly sloping generally planar bottom wall section 16 by an intermediate backwardly, downwardly sloping generally planar wall section 18. A forwardly extending peripheral wall 20 is integral with the upper and lower back wall sections 14 and 16 and extends forward with a somewhat rounded peripheral forward edge 22 forming the forwardmost portion thereof, as seen in FIGS. 2 and 3. The forward edge 22 is formed with side mounting flanges 24 and 26 and an upper mounting flange 28. These flanges provide a means for attachment of the box directly to building frame member such as a two-by-four stud 30 using nails 32 as shown. The nails are driven through holes such as 33 formed in the mounting flanges 24, 26 and 28. Alternatively, the upper mounting flange 28 may be secured by screws to a length of HYCO (Trademark) strap (not shown) nailed horizontally between adjacent studs.
The outlet box 10 preferably forms a recessed cavity having a width of approximately five inches and a height of approximately five and one-half inches. The upper back wall section 14 preferably forms about half of the entire back wall or up to about two and one-half inches. The wall section 14 is provided with a pair of apertures or holes 34 (FIG. 4) in which suitable hot and cold water valves are mounted. The box 10 is constructed to accommodate any suitable valves such as those commonly referred to as boiler drain valves or a single actuator double valve 35 such as that illustrated. The illustrated valve 35 is commonly referred to as a single lever washing machine outlet valve and is more fully described in detail in U.S. Pat. No. 3,234,958 incorporated herein by reference. The lever 35a may be readily grasped inside the compact box to simultaneously turn both the hot and cold water 0N or OFF.
The valve 35 is mounted as illustrated so that the outlets for connection of the hot and cold water supply hoses (not shown) to the washing machine extend downwardly. This way the washing machine water supply hoses may extend down along the front of the wall in which the outlet box is mounted in a manner that avoids kinking of the hoses. Similarly, the inlet shanks 35b of the valve body project outward behind the upper back wall section 14 as shown in FIG. 2. The back wall 14 is provided with the pair of spaced apart holes 34 as shown in FIG. 4 to permit the threaded inlet shanks 35b of the valve 35 to be mounted in the illustrated manner. Retaining nuts 36 (FIG. 2) screw over the threaded inlet shanks 35b to tightly secure the valve 35 to the wall 14. A portion of the right valve inlet shank 35b has been omitted in FIG. 4 to show the edge of one aperture 34.
This arrangement of the valve inlet holes 34 provides for convenient mounting or connection to water supply lines disposed in the building wall. The shallow washing machine outlet box constructed as illustrated provides a compact and convenient arrangement for easy mounting in building wall structure while accommodating the presence of water lines and the like that may be disposed in the wall structure directly behind the box. Since the valve shanks 35b extend horizontally, and because there is room in the wall behind the outlet box 10, the water supply lines can be connected from any direction, i.e., extending vertically from above or below, or horizontally from the left or the right. Conventional washing machine outlet boxes orient the valve shanks vertically and have no space in the wall behind them. Therefore the plumber has to route supply lines around and to the valve shanks with extra pipe elbows and pipe sections. This requires more soldering or adhesion welding and presents the possibility of more leaks.
The peripheral wall 20 is formed of the peripheral forward edge 22 in a rounded curved configuration folding or extending back so that the mounting flanges 24, 26 and 28 are spaced back of the forward edge 22 as shown in FIGS. 2 and 3. This positions the mounting flanges behind suitable wall board. This enables the mounting of the box 10 with wall board panel 38 extending to a position flush with the peripheral forward edge 22.
The lower bottom wall section 16 is formed with an outlet aperture 40 (FIG. 1) accommodating a drain line outlet. The drain line outlet is provided with a suitable mount such as with a tubular sleeve 42 (FIG. 2) of ABS or PVC that surrounds a sheet metal tube 44. The tube 44 is clamped at the opposite ends such as by crimping to form flanges 46 and 48 over the ends of the sleeve 42 and within the peripheral edge of aperture 40. This provides an outlet coupling to which an outlet or drain line pipe of PVC or ABS may be adhesively bonded in the usual manner. Typically a forty-five degree elbow will be solvent welded to the sleeve 42 and to a drain pipe in the wall.
As best seen in FIG. 2, the lower bottom wall 16 section preferably slopes at an angle of about forty-five degrees downward and forwardly to the bottom forward edge of the box 10. The intermediate wall section 18 preferably slopes downward and backward from the lower edge of the upper back wall 14 section to its intersection with the upper edge of the upper edge of wall section 16 at an angle of about forty-five degrees. This construction provides a shallow washing machine outlet box capable of fully accommodating water supply valves for connection to a washing machine and an outlet drain line within minimum space.
The outlet box 10 is provided with a peripheral escutcheon or cover plate 50 shown in part in FIGS. 1, 2 and 3 which is also preferably formed of sheet metal by stamping or drawing like the main box 10. This peripheral cover plate 50 covers the edges of wall board panel 38 and the like to form a finished installation. As shown in FIG. 3, the cover plate 50 is formed with downturned inner and outer edges to provide a smooth finished structure. The cover plate 50 is preferably provided with mounting holes for insertion of sheet metal screws 52 as shown in FIG. 3 for securing to the outlet box 10. Preferably each screw 52 mates with an opening or bore 54 in the forward edge 22 of the box 10. This provides a secure attachment of the cover plate 50 to the outlet box 10 and the surrounding structure.
Referring to FIGS. 5 and 7, a conventional washing machine outlet box 56 includes a pair of vertically oriented boiler drain valves 58 and 60 having horizontally extending threaded male outlets 62 and 64. A DWV drain pipe 66 extends vertically from the horizontal bottom wall 56a of the washing machine outlet box 56. Flanges or ears 67 and 68 extend from opposite sides of the washing machine outlet box 56 and are nailed to adjacent studs 70 and 72. The lower end of the drain pipe 66 is connected to a U-shaped trap 74 which in turn is connected to a ninety degree elbow 76 to a trap arm 78. A portion of the elbow 76 extends through a hole bored in the stud 70. A hot water supply line 80 is connected to the shank 58a of the hot water boiler drain valve 58. The hot water supply line 80 extends through a hole in the stud 72. However, because the outer diameter of the drain pipe 66 is substantial, there is insufficient room to bring the cold water supply line 82 across the drain pipe 66 to connect to the shank 60a to the cold water boiler drain valve 60. Instead, the cold water supply line 82 must extend to through both studs 70 and 72 above the washing machine outlet box 56. Segments of pipe 84, 86 and 88 are then soldered to the cold water supply line via elbows 90, 92 and 04 so that it can pass through the stud 70 again before being connected to the shank 60a of the cold water boiler drain valve 60. Clearly, the prior art installation illustrated in FIG. 7 requires a significant amount of additional plumbing, and more particularly, the cutting, fitting, and soldering of a significant number of Copper pipe segments 84, 86 and 88 as well as the Copper ninety degree elbows 90, 92 and 94.
FIGS. 6 and 8 illustrate the installation of the compact washing machine outlet box 10 of the present invention. The outlet box 10 is secured midway between the vertical studs 70 and 72 with a segment of HYCO strap 96 which is nailed to the studs. The hot and cold water supply lines 80 and 82, extend parallel through holes in the studs 72 and are connected to the valve shanks 35b from the same side. A forty-five degree DWV elbow 98 is connected over the end of the angled sleeve 42 (not visible in FIGS. 6 and 8). The lower end of the elbow 98 is connected to the upper end of the drain pipe 66. It can be seen that the installation of the compact washing machine outlet box 10 of the present invention is much shallower. There is room to bring both water supply lines horizontally to the outlet box and connect them to the valve shanks 35b from the same side, because of the horizontal orientation of these valve shanks.
While I have illustrated and described my invention by way of a specific embodiment, it is to be understood that numerous changes and modifications may be made in the illustrated embodiment without departing from the spirit and scope of the invention as defined in the appended claims.
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A forwardly opening low profile washing machine outlet box configured so that it can be stamped as a unitary piece of sheet metal comprises a back wall having an upper vertical section and a lower downwardly extending forwardly sloping section, a forwardly extending peripheral wall integral with and extending forwardly from a peripheral edge of the back wall, first and second apertures in the upper wall section for mounting first and second valve shanks for receiving first and second water supply lines, and an enlarged aperture in said lower wall section for connecting to a drain line and for receiving a washing machine drain hose.
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RELATED APPLICATION INFORMATION
[0001] This application is a continuation application of U.S. application Ser. No. 15/445,731, entitled “RFID Switch Tag,” filed Feb. 28, 2017, which is a continuation application of U.S. application Ser. No. 14/578,196, entitled “RFID Switch Tag,” filed Dec. 19, 2014, now U.S. Pat. No. 9,582,746, which is a continuation application of U.S. application Ser. No. 14/060,407, entitled “RFID Switch Tag,” filed Oct. 22, 2013, now U.S. Pat. No. 8,944,337, which is a continuation application of U.S. application Ser. No. 13/465,834, filed May 7, 2012, entitled “RFID Switch Tag,” now U.S. Pat. No. 8,561,911, which claims the benefit of priority under 35 U.S.C 119(e) to U.S. Provisional Application No. 61/487,372, entitled “RFID Switch Tag,” filed May 18, 2011 and claims the benefit of priority under 35 U.S.C 119(e) to U.S. Provisional Application No. 61/483,586, entitled “RFID Switch Tag,” filed May 6, 2011, all of which are incorporated herein by reference as if set forth in full.
BACKGROUND
1. Field of the Invention
[0002] The embodiments described herein relate generally to the field of radio-frequency identification (RFID) devices, and more particularly, to RFID switch tags.
2. Related Art
[0003] Conventional RFID tags lack the ability to be deactivated. However, there are certain situations where it is actually desirable to have an RFID tag deactivated. For example, in the context of traveling, RFID tags will often contain sensitive personal information stored within, for instance, an e-Passport, a visa, or a national identification card. Such information may contain the traveler's name, birth date, place of birth, nationality, and/or biometric information associated with that traveler. This information is intended to be read only by customs officials or other governmental authorities when the traveler enters or exits a country. However, since the read range of RFID tags can extend up to 30 feet, since an RFID tag does not need to be directly in the line of sight of an RFID reader, this sensitive information may be read by any number of unauthorized individuals as the individual walks through a train station or an airport. Unless the traveler houses his travel documents within a Faraday shield or other type of electro-resistant casing (which most travelers do not have), the sensitive information stored within the RFID tag remains perpetually at risk of being read by these unauthorized parties.
[0004] As a second example, consider RFID tags that are installed within automobiles, where such tags are used to facilitate automatic billing for the repeated use of certain toll-roads. In some of these toll-roads, the use of a car-pool lane is considered free of charge (which may be validly used, for example, when the automobile is housing at least one passenger other than the driver). Since a driver's RFID tag may not be deactivated, however, the RFID tag may respond to an interrogation signal issued from the toll-gate even when the driver has validly used the carpool lane. The result is that the driver may be billed for using the toll-road even when such use should have been considered free of charge because of the driver's valid use of the car-pool lane.
[0005] What is needed is a system for an RFID tag that may be easily activated or deactivated. Ideally, the system should be versatile and provide a clear sensory indication of the operational status of the RFID tag (i.e., activated or deactivated).
SUMMARY
[0006] Various embodiments of the present invention are directed to RFID switch devices. Such RFID switch devices advantageously enable manual activation/deactivation of the RF module. The RFID switch device may include a RF module with an integrated circuit adapted to ohmically connect to a substantially coplanar conductive trace pattern, as well as booster antenna for extending the operational range of the RFID device. The operational range of the RFID switch device may be extended when a region of the booster antenna overlaps a region of the conductive trace pattern on the RF module via inductive or capacitive coupling. In some embodiments, all or a portion of the booster antenna may at least partially shield the RF module when the RFID switch device is in an inactive state. The RFID switch device may further include a visual indicator displaying a first color if the RFID switch device is in an active state and/or a second color if the RFID switch device is in an inactive state.
[0007] In a first exemplary aspect, an RFID device is disclosed. In one embodiment, the RFID device comprises: a booster antenna adapted to extend the operational range of the RFID device; an RF module comprising an integrated circuit and a set of one or more conductive traces, wherein at least one conductive trace of said set of one or more conductive traces is adapted to electrically couple to a coupling region of the booster antenna when the coupling region of the booster antenna is located in a first position relative to said set of one or more conductive traces; and a switching mechanism adapted to change the position of the coupling region of the booster antenna relative to the position of said at least one conductive trace.
[0008] In a second exemplary aspect, an RFID transponder is disclosed. In one embodiment, the RFID transponder comprises: a first substrate comprising a first conductive trace pattern, wherein at least a portion of the first substrate is adapted to serve as an antenna for the RFID transponder; a second substrate comprising an integrated circuit and a second conductive trace pattern, wherein at least a portion of the second conductive trace pattern is adapted to electrically couple with at least a portion of the first conductive trace pattern when the first substrate is located in a first position relative to the second substrate; and a switching mechanism adapted to switch the position of the first substrate between a first position and at least a second position.
[0009] In a third exemplary aspect, an RFID device is disclosed. In one embodiment, the RFID device comprises: a booster antenna adapted to extend the operational range of the RFID device; a first RF module comprising a first integrated circuit and a first conductive trace pattern, wherein at least a portion of the first conductive trace pattern is adapted to electrically couple to a coupling region of the booster antenna when the coupling region of the booster antenna is located in a first position relative to the first conductive trace pattern; a second RF module comprising a second integrated circuit and a second conductive trace pattern, wherein at least a portion of the second conductive trace pattern is adapted to electrically couple to the coupling region of the booster antenna when the coupling region of the booster antenna is located in a second position relative to the second conductive trace pattern; and a switching mechanism adapted to change the position of the coupling region of the booster antenna relative to the positions of said first and second RF modules.
[0010] In a fourth exemplary aspect, an RFID device is disclosed. In one embodiment, the RFID device comprises: a first booster antenna adapted to extend the operational range of a first RF module; a second booster antenna adapted to extend the operational range of a second RF module; the first RF module comprising a first integrated circuit and a first conductive trace pattern, wherein at least a portion of the first conductive trace pattern is adapted to electrically couple to a coupling region of the first booster antenna when the coupling region of the first booster antenna is located in a first position relative to the first conductive trace pattern; a second RF module comprising a second integrated circuit and a second conductive trace pattern, wherein at least a portion of the second conductive trace pattern is adapted to electrically couple to the coupling region of the second booster antenna when the coupling region of the second booster antenna is located in a second position relative to the second conductive trace pattern; and a switching mechanism adapted to change the position of the coupling region of the first booster antenna relative to the first RF module, and the position of the coupling region of the second booster antenna relative to the second RF module.
[0011] In a fifth exemplary aspect, an RFID device is disclosed. In one embodiment, the RFID device comprises: a first booster antenna adapted to extend the operational range of an RF module as used with a first RFID service; a second booster antenna adapted to extend the operational range of the RF module as used with a second RFID service; the RF module comprising an integrated circuit and a conductive trace pattern, wherein at least a portion of the conductive trace pattern is adapted to electrically couple to a coupling region of the first booster antenna when the coupling region of the first booster antenna is located in a first position relative to the conductive trace pattern; and wherein at least a portion of the conductive trace pattern is adapted to electrically couple to a coupling region of the second booster antenna when the coupling region of the second booster antenna is located in a second position relative to the conductive trace pattern; and a switching mechanism adapted to change the position of the RF module relative to the respective coupling regions of the first and second booster antennas.
[0012] Other features and advantages of the present invention should become apparent from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Various embodiments disclosed herein are described in detail with reference to the following figures. The drawings are provided for purposes of illustration only and merely depict typical or exemplary embodiments. These drawings are provided to facilitate the reader's understanding of the invention and shall not be considered limiting of the breadth, scope, or applicability of the embodiments. It should be noted that for clarity and ease of illustration these drawings are not necessarily made to scale.
[0014] FIG. 1 is a block diagram illustrating an exemplary RFID system according to one embodiment of the present invention.
[0015] FIG. 2A is a block diagram illustrating an exemplary RFID switch tag with its RF module located in a first position relative to its booster antenna according to one embodiment of the present invention.
[0016] FIG. 2B is a block diagram of the exemplary RFID switch tag with its RF module located in a second position relative to its booster antenna according to the embodiment depicted in FIG. 2A .
[0017] FIG. 2C is a block diagram of the RFID switch tag depicted in FIGS. 2A and 2B as depicted within an exemplary casing featuring a position-altering mechanism according to one embodiment of the present invention.
[0018] FIG. 3 is a block diagram illustrating an exemplary RFID switch tag including two RF modules and a single booster antenna according to one embodiment of the present invention.
[0019] FIG. 4 is a block diagram illustrating an exemplary RFID switch tag including two RF modules and two corresponding booster antennas according to one embodiment of the present invention.
[0020] FIG. 5 is a block diagram illustrating an exemplary RFID switch tag including a single RF module and two booster antennas that are tuned to different frequencies according to one embodiment of the present invention.
[0021] FIG. 6A is a front-side view of an exemplary switch-activated RFID tag according to one embodiment of the present invention.
[0022] FIG. 6B is a perspective view of the back side of the exemplary switch-activated RFID tag according to the embodiment depicted in FIG. 6A .
[0023] FIG. 7A is a back-side view of an exemplary circular-shaped and rotatable RFID switch tag in a first position according to one embodiment of the present invention.
[0024] FIG. 7B is a back-side view of the exemplary circular-shaped and rotatable RFID switch tag in a second position according to the embodiment depicted in FIG. 7A .
[0025] FIG. 7C is a front-side view of the exemplary circular-shaped and rotatable RFID switch tag depicted in FIGS. 7A and 7B .
[0026] FIG. 8A is a perspective view of the back side of an exemplary triangular-shaped and rotatable RFID switch tag in a first position according to one embodiment of the present invention.
[0027] FIG. 8B is a back-side view of the exemplary triangular-shaped and rotatable RFID switch tag in a second position according to the embodiment depicted in FIG. 8A .
[0028] FIG. 8C is a front-side of the exemplary triangular-shaped and rotatable RFID switch tag depicted in FIGS. 8A and 8B .
[0029] FIG. 9A is a perspective view of the back side of an exemplary switch-activated RFID tag according to one embodiment of the present invention.
[0030] FIG. 9B is a front-side view of the exemplary switch-activated RFID tag depicted in FIG. 9A .
[0031] FIG. 10 is a perspective view of an exemplary slide-activated RFID tag according to one embodiment of the present invention.
DETAILED DESCRIPTION
[0032] RFID is an automatic identification method, relying on storing and remotely retrieving data using devices called RFID tags or transponders. The technology relies on cooperation between an RFID reader and an RFID tag. RFID tags can be applied to or incorporated within a variety of products, packaging, and identification mechanisms for the purpose of identification and tracking using radio waves. For example, RFID is used in enterprise supply chain management to improve the efficiency of inventory tracking and management. Some tags can be read from several meters away and beyond the line of sight of the RFID reader.
[0033] Most RFID tags contain at least two parts: One is an integrated circuit for storing and processing information, for modulating and demodulating a radio-frequency (RF) signal, and for performing other specialized functions. The second is an antenna for receiving and transmitting the signal. As the name implies, RFID tags are often used to store an identifier that can be used to identify the item to which the tag is attached or incorporated. An RFID tag may also contain non-volatile memory for storing additional data as well. In some cases, the memory may be writable or electrically erasable programmable read-only memory (i.e., EEPROM).
[0034] Most RFID systems use a modulation technique known as backscatter to enable the tags to communicate with the reader or interrogator. In a backscatter system, the interrogator transmits a Radio Frequency (RF) carrier signal that is reflected by the RFID tag. In order to communicate data back to the interrogator, the tag alternately reflects the RF carrier signal in a pattern understood by the interrogator. In certain systems, the interrogator can include its own carrier generation circuitry to generate a signal that can be modulated with data to be transmitted to the interrogator.
[0035] RFID tags come in one of three types: passive, active, and semi passive. Passive RFID tags have no internal power supply. The minute electrical current induced in the antenna by the incoming RF signal from the interrogator provides just enough power for the, e.g., CMOS integrated circuit in the tag to power up and transmit a response. Most passive tags transmit a signal by backscattering the carrier wave from the reader. This means that the antenna has to be designed both to collect power from the incoming signal and also to transmit the outbound backscatter signal.
[0036] Passive tags have practical read distances ranging from about 10 cm (4 in.) (ISO 14443) up to a few meters (Electronic Product Code (EPC) and ISO 18000-6), depending on the chosen radio frequency and antenna design/size. The lack of an onboard power supply means that the device can be quite small. For example, commercially available products exist that can be embedded in a sticker, or under the skin in the case of low frequency RFID tags.
[0037] Unlike passive RFID tags, active RFID tags have their own internal power source, which is used to power the integrated circuits and to broadcast the response signal to the reader. Communications from active tags to readers is typically much more reliable, i.e., fewer errors, than from passive tags. Active tags, due to their on-board power supply, may also transmit at higher power levels than passive tags, allowing them to be more robust in “RF challenged” environments, such as high environments, humidity or with dampening targets (including humans/cattle, which contain mostly water), reflective targets from metal (shipping containers, vehicles), or at longer distances. In turn, active tags are generally bigger, caused by battery volume, and more expensive to manufacture, caused by battery price. Many active tags today have operational ranges of hundreds of meters, and a battery life of up to 10 years. Active tags can include larger memories than passive tags, and may include the ability to store additional information received from the reader, although this is also possible with passive tags.
[0038] Semi-passive tags are similar to active tags in that they have their own power source, but the battery only powers the microchip and does not power the broadcasting of a signal. The response is usually powered by means of backscattering the RF energy from the reader, where energy is reflected back to the reader as with passive tags. An additional application for the battery is to power data storage. The battery-assisted reception circuitry of semi-passive tags leads to greater sensitivity than passive tags, typically 100 times more. The enhanced sensitivity can be leveraged as increased range (by one magnitude) and/or as enhanced read reliability (by reducing bit error rate at least one magnitude).
[0039] FIG. 1 is a block diagram illustrating an exemplary RFID system according to one embodiment of the present invention. As shown by this figure, RFID interrogator 102 communicates with one or more RFID tags 110 . Data can be exchanged between interrogator 102 and RFID tag 110 via radio transmit signal 108 and radio receive signal 112 . RFID interrogator 102 may include RF transceiver 104 , which contains both transmitter and receiver electronics configured to respectively generate and receive radio transit signal 108 and radio receive signal 112 via antenna 106 . The exchange of data may be accomplished via electromagnetic or electrostatic coupling in the RF spectrum in combination with various modulation and encoding schemes.
[0040] RFID tag 110 can be a transponder attached to an object of interest and serve as an information storage mechanism. The RFID tag 110 may itself contain an RF module 120 (including an integrated circuit 122 and conductive trace pattern 124 ) as well as its own antenna 126 . All or a portion of the antenna 126 may be adapted to interact with the conductive trace pattern 124 in order to gather energy from the RF field to enable the device circuit 122 to function. In some embodiments, the antenna 126 used to gather the RF energy may be in a different plane as that of the integrated circuit 122 .
[0041] The data in the transmit signal 108 and receive signals 112 may be contained in one or more bits for the purpose of providing identification and other information relevant to the particular RFID tag application. When RFID tag 110 passes within the range of the radio frequency magnetic or electromagnetic field emitted by antenna 106 , RFID tag 110 is excited and transmits data back to RF interrogator 102 . A change in the impedance of RFID tag 110 can be used to signal the data to RF interrogator 102 via the receive signal 112 . The impedance change in RFID tag 110 can be caused by producing a short circuit across the tag's antenna connections (not shown) in bursts of very short duration. RF transceiver 104 can sense the impedance change as a change in the level of reflected or backscattered energy arriving at antenna 106 .
[0042] Digital electronics 114 (which in some embodiments comprises a microprocessor with RAM) performs decoding and reading of the receive signal 112 . Similarly, digital electronics 114 performs the coding of the transmit signal 108 . Thus, RF interrogator 102 facilitates the reading or writing of data to RFID tags, e.g. RFID tag 110 that are within range of the RF field emitted by antenna 104 . Together, RF transceiver 104 and digital electronics 114 comprise reader 118 . Finally, digital electronics 114 and can be interfaced with an integral display and/or provide a parallel or serial communications interface to a host computer or industrial controller, e.g. host computer 116 .
[0043] As stated above, conventional RFID devices lack the ability to be manually activated or deactivated. Various embodiments of the present invention are therefore directed to an RFID switch tag adapted to allow a user to manually change the operational state of the RFID device by activation of a lever, switch, knob, slider, rotating member, or other similar structure.
[0044] As shown generally by the embodiments depicted in FIGS. 2A-2C , a tag may provided that includes an RF module, strap, or interposer, as well as a booster antenna 210 . The RF module 220 may comprise an RFID integrated circuit in an ohmic connection to impedance matched conductive trace pattern in the same plane as the integrated circuit. Even though the RF module 220 is fully functional and testable, it may have a limited range of operation due to the small surface area of the conductive trace pattern.
[0045] According to one embodiment, the operational range of the RF module 220 can be increased by conductive or inductive coupling. For example, an impedance matched booster antenna 210 can be used in conjunction with the RF module 220 . In one embodiment, this booster antenna 210 consists of a conductive trace pattern on a substrate. In this example, there is no RF device on the booster antenna 210 . Rather, the RF module 220 and booster antenna 210 are provided with an area where they can overlap so that the capacitive or inductive coupling of energy occurs. The RF energy gathered from the booster antenna 210 may be transferred through the RF module substrate and conducted into the RF module 220 . This is illustrated in FIG. 2A . As shown, the RF module 220 may be positioned relative to the booster antenna 210 such that RF energy gathered via the booster antenna 210 is transferred to the RF module 220 .
[0046] While not shown, RF module 220 may comprise an RFID integrated circuit and a conductive trace pattern. These trace patterns can then be either inductively or capacitively coupled with a booster antenna 210 . For optimal performance, the booster antenna 210 may be matched with the RFID integrated circuit inputs. If RF module 220 is displaced or not sufficiently coupled with antenna 210 , then the operational range of the tag can be significantly reduced.
[0047] Thus, the placement of the RF module 220 with respect to the booster antenna 210 may alter the operational range and performance of the RFID tag 110 . This is illustrated in FIG. 2B . In FIG. 2B , the relative positions of the RF module 220 and the booster antenna 210 are different than the arrangement shown in FIG. 2A . In the arrangement of FIG. 2B , a smaller portion, or none, of the RF energy collected by the booster antenna 210 is transferred to the RF module 220 . In this manner, the effective operational range of the RFID tag 110 may be reduced as compared to the arrangement of FIG. 2A . In fact, because RF module 220 is completely or at least partially shielded by a portion of antenna 210 , RFID communications between the RFID tag 110 and the RFID reader interrogator 102 may be completely halted. This non-operational state may be useful, for instance, in situations where it is desirable to render the RFID tag 110 unresponsive to an RFID interrogation signal. For example, as noted above, when no toll is due on a toll road due to the number of passengers in the car, it may be desirable for the RFID tag 110 to be unresponsive to an RFID interrogation issued by a toll road portal system.
[0048] In some embodiments, a mechanism is provided for selectively altering the relative position of RF module 220 and the booster antenna 210 . Advantageously, this allows a user to selectively displace the RF module 220 from an optimized position over the booster antenna 210 rendering it unresponsive or detuned such that it will not respond at a sufficient measurement or perform adequately. Thus, for example, when taking a toll road that is free for car-pools, a user can manipulate the mechanism in order to effectively deactivate the RFID tag 110 and avoid paying the toll. In various embodiments, the mechanism may include a switch, lever, knob, slider, rotatable member, or any other device or construction which serves this purpose.
[0049] A selectively-activatable RFID tag 110 is depicted in FIG. 2C . The RFID tag 110 may comprise a slider mechanism 240 and an indicator area 250 , where the RF module 220 is mechanically coupled to the slider 240 . By manipulating the slider, a user modifies the relative positions of the RF module 220 and the booster antenna 210 . The indicator area 250 may provide a visual indication of the status of the RFID tag 110 . For example, if the RF module 220 and booster antenna 210 are positioned for effective transfer of RF power, the indicator area 250 may present a first visual indication such as a green color. Conversely, if the RF module 220 and booster antenna 210 are not positioned for effective transfer of RF power, the indicator area may provide a second visual indication such as a red color. In this manner, one or more individuals can be alerted of the effective operability of the RFID tag 110 .
[0050] FIG. 3 is a block diagram illustrating an exemplary RFID switch tag including two RF modules and a single booster antenna according to one embodiment of the present invention. As shown, a single booster antenna 310 is provided. However, in this embodiment two RF modules 322 and 324 are shown. The booster antenna 310 and RF modules 322 and 324 may be positioned such that only one of the two modules 322 and 324 is effectively coupled to the booster antenna 310 at any one time. For example, as shown in FIG. 3 , RF module 322 is coupled to the booster antenna 310 while RF module 324 is shielded. Thus, RF module 322 is effectively tuned and responsive, while RF module 324 is effectively detuned and unresponsive.
[0051] A mechanism (e.g., switch, slider, knob, lever, rotatable member, etc.) such as the slider 240 depicted in FIG. 2C may be provided for selectively altering the relative position of RF module 322 and 324 and the booster antenna 310 . In this manner, the positioning altering mechanism can be manipulated to selectively cause zero or one of the two modules 322 and 324 to be coupled to the antenna 310 . For example, in a first state, only module 322 may be coupled with the booster antenna 310 . In a second state, only module 324 may be coupled with booster antenna 310 . In a third state, neither modules 322 or 324 are coupled with the booster antenna 310 .
[0052] Advantageously, this arrangement allows a single RFID tag 110 to be used for multiple services. For example, one RF module, e.g. module 322 , can be associated with toll road portal system. The other RF module, e.g., module 324 , can be associated with a system for tracking car-pool lane use. The user can manipulate the position altering mechanism in order to couple the booster antenna 310 to the RF module 322 or 324 that is appropriate for current usage. In some embodiments, one or more visuals indicators may also be provided to indicate which RF module 322 or 324 is currently coupled to the booster antenna. Note also that while only two RF modules 322 and 324 are depicted in FIG. 3 , any number of RF modules may be used in accordance with embodiments of the present invention.
[0053] In the embodiment of FIG. 3 , the RF modules 322 and 324 may be aligned horizontally and the direction of movement caused by manipulation of the position altering mechanism may likewise be horizontal. In other embodiments, however, the RF modules 322 and 324 may be aligned vertically and the direction of movement may be vertical. In still other embodiments, the RF modules 322 , 324 may be arranged in an arcuate manner and the direction of motion may also be arcuate. Various other arrangements of the RF modules 322 and 324 , the booster antenna 310 , and the direction of movement are also possible according to embodiments of the present invention.
[0054] FIG. 4 is a block diagram illustrating an exemplary RFID switch tag including two RF modules and two corresponding booster antennas according to one embodiment of the present invention. As shown by the figure, two booster antennas 412 and 414 and two RF modules 422 and 424 are provided. In some embodiments, each RF module 422 and 424 may be associated with a different RFID service such that a user may independently tune each pair of RF modules 422 and 424 and booster antennas 412 and 414 present within the RFID tag 110 . Note that while only two pairs of RF modules 422 and 424 and booster antennas 412 and 414 are depicted in FIG. 4 , any number of RF module/booster antenna pairs may be utilized according to embodiments of the present invention.
[0055] While the embodiment depicted in FIG. 4 depicts the antennas 412 and 414 as bearing similar physical properties (such as size and shape), each booster antenna 412 and 414 may have differing physical properties according to alternative embodiments. These differences may result in different properties for gathering RF energies. In some embodiments, the antennas 412 and 414 may be specifically tuned to different frequencies.
[0056] According to some embodiments, each of the RF modules 422 and 424 may be attached to single position altering mechanism (not shown). In this manner, a user can manipulate the mechanism such that only one of the two RF modules 422 and 424 is coupled to its respective boost antenna 412 or 414 at any one time. A visual indicator may be provided to indicate which RF module 422 or 424 is currently coupled to its respective booster antenna 412 and 414 . In some embodiments, the position altering mechanism may be manipulated such that both or neither of the RF modules 422 or 424 are coupled to the respective boost antennas 412 or 414 at the same time.
[0057] In other embodiments, each of the RF modules 422 and 424 may be attached to a separate position altering mechanism (not shown). According to these embodiments, both, neither, or only one of the RF modules 422 or 424 may be coupled to the respective boost antennas 412 and 414 at the same time. The visual indicator may display a first color if the first RF module 422 is active and a second color if the second RF module 424 is active.
[0058] Note that in the embodiment depicted in FIG. 4 , the booster antennas 412 and 414 may be arranged along a vertical axis, and a horizontal direction of motion is utilized via manipulation of the position altering mechanism. However, persons skilled in the art will appreciate that the booster antennas 412 and 414 may be arranged horizontally, vertically, along an arc, in different planes, or in various other manners. Additionally, the direction of motion may switch the RF modules 422 and 424 between coupled and uncoupled positions for the respective booster antennas 412 and 414 .
[0059] FIG. 5 is a block diagram illustrating an exemplary RFID switch tag including a single RF module and two booster antennas that are tuned to different frequencies according to one embodiment of the present invention. As shown, a single RF module 520 may be provided, along with two booster antennas 512 and 514 . The booster antennas 512 and 514 may be configured with different physical properties to enable the RF module 520 to switch between separate RFID services. In this respect, the RF module 520 may be mechanically coupled to a position altering mechanism such that the tag can be switched to select one or none of the booster antennas 512 and 514 . A visual indicator may display a first color if the first booster antenna 512 corresponding to a first RFID service is selected and a second color if the second booster antenna 514 corresponding to a second RFID service is selected.
[0060] As in the case of FIG. 4 , the booster antennas 512 and 514 may be arranged along a vertical axis and the direction of motion of the RF module 520 caused by manipulation of the position altering mechanism is vertical. In other embodiments, the booster antennas 512 and 514 may be arranged horizontally, along an arc, in different planes, or in another manner and the direction of motion is adapted to switch the RF module 520 between the booster antennas 512 and 514 .
[0061] FIGS. 6A-10 generally depict various embodiments of RFID switch tags which may be utilized, for example, within an automobile setting. Each of the RFID switch tags may be affixed, fastened, or adhered to a windshield, rearview mirror, automobile exterior, or to various other areas of the automobile according to embodiments of the present invention.
[0062] FIG. 6A is a front-side view of an exemplary switch-activated RFID tag according to one embodiment of the present invention, while FIG. 6B is a perspective view of the back side of the exemplary switch-activated RFID tag according to the embodiment depicted in FIG. 6A . As shown by the figure, the RFID tag may include a slider configuration 602 with a window 604 on the outside and one or more icon graphics 606 on the opposite side. In some embodiments, an optional mounting component (not shown) may be used to adhere, fasten, or clip the RFID tag to a visor, for example.
[0063] FIG. 7A is a back-side view of an exemplary circular-shaped and rotatable RFID switch tag in a first position according to one embodiment of the present invention, FIG. 7B is a back-side view of the exemplary circular-shaped and rotatable RFID switch tag in a second position according to the embodiment depicted in FIG. 7A , while FIG. 7C is a front-side view of the exemplary circular-shaped and rotatable RFID switch tag depicted in FIGS. 7A and 7B . As depicted in FIGS. 7A and 7B , a circular shaped member 702 may be rotated, for example, clockwise or counterclockwise, in order to activate or deactivate the RFID switch tag. Icon graphics 706 on the back-side may be used to inform one or more individuals of the activation state of the RFID switch tag. Optionally, a window 704 on the opposite side of the RFID switch tag (see FIG. 7C ) may be used to reveal the activation state of the RFID switch tag to the outside.
[0064] FIG. 8A is a perspective view of the back side of an exemplary triangular-shaped and rotatable RFID switch tag in a first position according to one embodiment of the present invention, FIG. 8B is a back-side view of the exemplary triangular-shaped and rotatable RFID switch tag in a second position according to the embodiment depicted in FIG. 8A , while FIG. 8C is a front-side of the exemplary triangular-shaped and rotatable RFID switch tag depicted in FIGS. 8A and 8B . FIGS. 8A-8C may operate similar to FIG. 7A-7C , but utilize a substantially triangular shape and design rather than a circular one. Various other shapes and designs may also be utilized in accordance with embodiments of the present invention.
[0065] FIG. 9A is a perspective view of the back side of an exemplary switch-activated RFID tag according to one embodiment of the present invention, while FIG. 9B is a front-side view of the exemplary switch-activated RFID tag depicted in FIG. 9A . As depicted in FIG. 9A , the RFID tag may utilize a slider configuration 902 with a windows on both sides 904 and 905 of the RFID tag. Such an RFID tag may be adhered to the window of the automobile or may also use a cradle system for mobility according to various embodiments.
[0066] FIG. 10 is a perspective view of a separate exemplary slide-activated RFID tag according to one embodiment of the present invention. According to some embodiments, no physical switch or level is utilized. Instead, the RFID tag may be activated or deactivated by manually sliding a first substrate 1002 to or from a casing 1004 .
[0067] While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not of limitation. The breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments. Where this document refers to technologies that would be apparent or known to one of ordinary skill in the art, such technologies encompass those apparent or known to the skilled artisan now or at any time in the future. In addition, the invention is not restricted to the illustrated example architectures or configurations, but the desired features can be implemented using a variety of alternative architectures and configurations. As will become apparent to one of ordinary skill in the art after reading this document, the illustrated embodiments and their various alternatives can be implemented without confinement to the illustrated example. One of ordinary skill in the art would also understand how alternative functional, logical or physical partitioning and configurations could be utilized to implement the desired features of the present invention.
[0068] Furthermore, although items, elements or components of the invention may be described or claimed in the singular, the plural is contemplated to be within the scope thereof unless limitation to the singular is explicitly stated. The presence of broadening words and phrases such as “one or more,” “at least,” “but not limited to” or other like phrases in some instances shall not be read to mean that the narrower case is intended or required in instances where such broadening phrases may be absent.
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Various embodiments of RFID switch devices are disclosed herein. Such RFID switch devices advantageously enable manual activation/deactivation of the RF module. The RFID switch device may include a RF module with an integrated circuit adapted to ohmically connect to a substantially coplanar conductive trace pattern, as well as booster antenna for extending the operational range of the RFID device. The operational range of the RFID switch device may be extended when a region of the booster antenna overlaps a region of the conductive trace pattern on the RF module via inductive or capacitive coupling. The RFID switch device may further include a visual indicator displaying a first color if the RFID switch device is in an active state and/or a second color if the RFID switch device is in an inactive state.
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DESCRIPTION
The invention relates to a layout for connecting two adjacent platforms of a turbomachine, as well as to a seal designed for use in said layout.
Turbomachine designs are often found in which certain elements such as the nozzles of the stator are made up of an assembly of parts which are themselves made up of a platform in the form of cylinder or cone sectors fitted with blades. The platforms are placed adjacent to each other to form a surface as continuous as possible, and they are sometimes provided, on their surface opposite the one from which the blades rise, with a layer of easily eroded material, often said to be "abradable" in this technique and whose role is to provide sealing under the platforms while undergoing local wear against facing rigid parts called wipers and which belong to the rotor. The wear of the layer makes it take the form of these parts while tolerating only a small clearance allowing the passage of almost no leakage.
As it is impossible to perfectly join the platforms, small clearances are left between their facing edge sides and allow gas leaks through said clearances. The prior art has already thought of combating these leaks by providing grooves in the faces opposite the platforms to receive a tongue seal which extends along the clearance and thus blocks the leakage paths in the radial direction towards the rotor. However, it was observed that the leaks in the axial direction of the machine, along the clearance, were also not to be neglected, especially as the abradable layer is also divided into sectors fixed to the respective platforms and which are also not contiguous, with the consequence that the section of the clearance in the axial direction is greatly increased.
The layout of the invention for connecting two adjacent platforms covered with a layer of easily eroded material on radially oriented faces is characterized by cavities extending radially over the platforms and through the layer, and opening onto the clearance, and by strips occupying the cavities and closing off the clearance. The strips thus serve to provide the required leak-tightness in the axial direction. The cavities advantageously are in the form of grooves which retain the strips suitably.
According to an important embodiment of the invention, on the platforms the cavities form channels open onto the clearance and onto the layer and having stop faces before edges of the platforms coinciding with ends of the clearance, and a seal is added which is provided with a core occupying the channels, the strips being joined to the core. One thus has a single seal thanks to which the assembly is easy.
Moreover, the seal may be designed easily so that it opposes the movement of the platforms thanks to its rigidity. A case in which this property is verified is that of a core having a U-section placed against the channels and covering the clearance, and curved ends parallel to the strips and placed against the channel stop faces.
Another object of the invention is the seal previously described and designed especially for this application.
The invention will now be described in greater detail through a particular embodiment in connection with the appended drawings in which:
FIG. 1 is an overall view of the layout, partially in cross section,
FIGS. 2 and 3 are two perpendicular sections of this embodiment,
and FIG. 4 illustrates another embodiment.
Represented are two platforms 1 and 2 in the form of a cylinder or cone sector which abut so as to have a common clearance 3, with an axial orientation in the machine. This clearance can be covered by a tab 4 whose principal faces are directed radially and whose side edges are sunk into facing grooves 5 and 6 provided in the edge sides of the platforms 1 and 2, and which are almost flush here with the surfaces 7 and 8 of the platforms carrying the blades 9. This is an already known construction whose purpose is to prevent gas leaks in the radial direction; the basic element of the invention is however a seal 10 composed of a core 11 with a U-section and strips 12 in a single piece with the core 11 and whose faces have an axial orientation.
The core 11 is engaged in axial channels 13 and 14 established on each of the platforms 1 and 2, and which open towards each other and towards the surfaces of the platforms 1 and 2 which are opposite the surfaces 7 and 8 and which cover part of the layer of easily eroded material, respectively 15 or 16 and which can consist of a honeycomb layer. Each of the layer parts 15 and 16 extends over the respective channel 13 or 14 so as to cover it and so that only the clearance 3 remains between them. This situation is such that the strips 12, which already divide the volume of the channels 13 and 14 into sections, must be more extensive and intimately mixed with the layer parts 15 and 16 to also close off this part of the clearance 3. An inset may be obtained in practice by providing notches in the layer parts 15 and 16 at the location of the strips 12 and by placing the strips 12 in these notches when the layer parts are placed and fixed to the platforms 1 and 2 proper.
It is seen that the strips 12 close off almost completely the clearance 3 and the channels 13 and 14 and considerably reduce gas leaks in the axial direction. The core 11 is advantageously placed against the surfaces of the channels 13 and 14 with little or no clearance. It can be terminated by curved edges 17 and 18 at the front and at the back, substantially parallel to the strips 12 and which fit, with no or practically no clearance, against stopping faces 19 and 20 of the channels 13 and 14 in the axial direction, which are near edges of the platforms 1 and 2. If the platforms 1 and 2 move mutually in the axial direction, they shear the core 11 which however has the ability to withstand and counter these undesired movements which could separate the platforms 1 and 2. The curved edges of the core 11, at the ends as well as on the sides, are also designed to hold the plate 25 supporting the parts 15 and 16 of the easily eroded layer and to prevent it from descending into the channels 13 and 14.
It is noted that it is suitable for the strips 12 to extend in front of furrows 21 separating peaks or wipers 22 of the rotor rubbing on the layer parts 15 and 16 and which shape them to complete the leak-tightness between a disk 23 of the rotor carrying these wipers 22 and the platforms 1 and 2; the strips 12 can project beyond the layer parts 15 and 16 to extend into the furrows 21.
It would be possible to consider the elimination of the tab 4 if, for example, the core 11 were perfectly against the bottom of the channels 13 and 14 or against their side wall. It would also be possible to replace the tab 4 by another seal. The seal 10 of the invention can thus be used perfectly independently.
Another embodiment is described with reference to FIG. 4. The seal 10 is omitted and the sealing device includes only the strips, here designated by the reference 28 and which occupy grooves 29 made in the platforms 1 and 2. These grooves 29 open onto the edge face towards the other platform, and extend in a generally radial direction through the thickness of the platforms and of the abradable layer parts 15 and 16, and up to the face of this layer opposite the platforms 1 and 2, on the one hand, and up to the axial groove 5 of the tab 4, on the other. The strips 28 could thus slip from the grooves 29, and fall on the disk 23 if they did not have a variable curvature, and designed here more precisely with an undulation 30 or an oblique part, separating two straight portions 31 and 32. The strips 28 are rounded with the same form and thus kept in their place.
Only one of the platforms (here 1) is represented in FIG. 4, but it is understood that the other is designed in the same manner and in particular that the strips 28 also extend in similar grooves of the other platform so as to totally close off the clearance 3. The channels 13 and 14 are advantageously omitted here, and the platforms 1 and 2 are designed with ribs 33 backing the grooves 29, which extend up to the abradable layer.
In this embodiment, as in the preceding one, the platforms 1 and 2 are held by the blades 9, themselves connected through their opposite end (not visible in the figures) to external platforms fixed to a stator ring and which can also be made up of juxtaposed sectors. Sealing devices similar to tabs and strips may be used to close off the clearances between these other sectors.
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A layout for connecting two platforms of a turbomachine which support blades. A common clearance between the blades is occupied by a seal which includes a core placed in channels under the surface of the platforms and strips which close off the clearance and which are embedded in a layer of easily eroded material. Not only do the core and the strips close off the clearances, but the seal can be designed with a sufficient stiffness to oppose any excessive movement of the platforms. The strips can also be used alone without the seal.
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FIELD OF THE DISCLOSURE
[0001] The present disclosure is generally directed toward illumination devices and systems.
BACKGROUND
[0002] Light-emitting diode (LED) lighting has become widely available to replace compact fluorescent lights (CFL) and incandescent products. LED lighting provides advantages including a reduction in power requirements, longer life and less environmental waste. Further, LED lighting is considered to provide improved aesthetics. Frequently, LED lighting is installed in a downlight configuration, causing unwelcomed glare. Also, traditional downlight LED installations provide only a binary on or off illumination, causing a user to either turn the LED lighting completely off (making a room too dark, for example during a presentation or while viewing a video) or completely on causing the aforementioned unwelcomed glare. No controllable dimming and/or controlled blending with other light sources is provided. Attempts to modify traditional LED installations to improve or mitigate the afore-mentioned problems traditionally do not complement and/or integrate with existing lighting systems.
SUMMARY
[0003] It is, therefore, one aspect of the present disclosure to provide a downlight auxiliary ring device comprising one or more light sources which provide a reflected or indirect downlight. It is also an aspect of the present disclosure to provide methods of control and use of the downlight auxiliary ring device.
[0004] The downlight auxiliary ring device, in some embodiments, is fitted with one or more light sources positioned on a distal portion of the auxiliary ring. The one or more light sources are arranged to emit light toward a reflective surface such that the reflected light is directed downward. The reflected light is of reduced glare than if emitted directly downward.
[0005] In one embodiment, an auxiliary ring is disclosed, the auxiliary ring comprising: a body comprising: a proximal portion configured to engage a perimeter surface of a downlight; and a distal portion configured to receive or support one or more light sources, the one or more light sources being positioned to emit light toward a reflective surface such that the light reflects downward.
[0006] In one embodiment, an illumination system is disclosed, the illumination system comprising: a downlight comprising an outer flange, the outer flange positioned proximate to a radial extremity of the downlight; an auxiliary ring comprising: a body, the body comprising a proximal portion configured to engage the outer flange of the downlight, and a distal portion configured to receive one or more light sources, wherein the proximal portion of the body of the auxiliary ring is secured to the outer flange of the downlight, wherein the one or more light sources are positioned to emit light toward a reflective surface.
[0007] The present disclosure will be further understood from the drawings and the following detailed description. Although this description sets forth specific details, it is understood that certain embodiments of the invention may be practiced without these specific details.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the disclosure and together with the general description of the disclosure given above and the detailed description of the drawings given below, serve to explain the principles of the disclosures.
[0009] It should be understood that the drawings are not necessarily to scale. In certain instances, details that are not necessary for an understanding of the disclosure or that render other details difficult to perceive may have been omitted. It should be understood, of course, that the disclosure is not necessarily limited to the particular embodiments illustrated herein.
[0010] The present disclosure is described in conjunction with the appended figures:
[0011] FIG. 1A is a cross-sectional side-view of an illumination system in accordance with at least some embodiments of the present disclosure;
[0012] FIG. 1B is a cross-sectional side-view of an illumination system in accordance with at least some embodiments of the present disclosure;
[0013] FIG. 2A is a bottom view of a downlight auxiliary ring device in accordance with at least some embodiments of the present disclosure;
[0014] FIG. 2B is a cross-sectional side-view along line A-A depicted in FIG. 2A ; and
[0015] FIG. 3 is a schematic-diagram representation of an illumination system in accordance with at least some embodiments of the present disclosure.
DETAILED DESCRIPTION
[0016] The ensuing description provides embodiments only, and is not intended to limit the scope, applicability, or configuration of the claims. Rather, the ensuing description will provide those skilled in the art with an enabling description for implementing the described embodiments. Preferred embodiments are described to illustrate the present invention, not to limit its scope, which is defined by the claims. Like elements in various embodiments are commonly referred to with like reference numerals. It being understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the appended claims.
[0017] Referring now to FIGS. 1-3 , representations and configurations of the device, methods of manufacture of the device, and methods of use of the device are shown.
[0018] In regard to FIGS. 1A-B , side-views of two configurations of an illumination system 10 are provided. The system 10 and components thereof will be described in accordance with at least some embodiments of the present disclosure.
[0019] FIGS. 1A-B depict a system 10 comprising downlight 20 , downlight lower portion 30 , downlight attachment springs 40 and downlight flange area 50 . Downlight 20 is shown mounted to a mounting surface 60 , such as a ceiling, wall, floor, or the like, emitting a downward light directly away from the mounting surface. The directly-emitted light will be referred to herein as downward light 70 , but it should be appreciated that embodiments of the present disclosure are not necessarily limited to ceiling installations.
[0020] One or more light sources 110 are disposed on an upper surface of auxiliary ring 100 . Light source(s) 110 are configured to emit light upwards at an angle which is offset from vertical (e.g., the direction of light emitted by the downlight), wherein the emitted light is reflected against a surface (here, mounting surface 60 ) such that the light is reflected downward (as indicated by light arrows 120 ).
[0021] Auxiliary ring 100 is shown in FIG. 1A with flange engaging downlight flange area 50 , while in FIG. 1B , auxiliary ring 100 does not include flange area. In the embodiment of FIG. 1A , the auxiliary ring 100 engages, via flange, between mounting surface 60 and downlight flange area 50 . In the embodiment of FIG. 1B , the auxiliary ring 100 engages, via flange, solely the downlight flange area 50 at the bottom surface of the downlight flange area 50 . Attachment of the auxiliary ring 100 to the downlight 20 in the embodiment of FIG. 1A may be of several means, to include gravity mount, friction mount, snap fit, adhesive, bolt and nut, and loop and eye. Attachment of the auxiliary ring 100 to the downlight 20 in the embodiment of FIG. 1B may be of several means, to include adhesive, snap fit, bolt and nut, and loop and eye.
[0022] The light sources 110 of the auxiliary ring 10 may be powered by a stand-alone power source or by a common power source with the downlight 20 . The power sources for one or both of the auxiliary ring 10 and the downlight 20 may be direct current (DC) or alternating current (AC). In one embodiment, the auxiliary ring is powered by a 12 volt AC power source.
[0023] The one or more light sources 110 may, in some embodiments, correspond to a Light Emitting Diode (LED), an array of LEDs, an Organic LED (OLED). In some embodiments, where the light sources 110 correspond to one or more LEDs, the LEDs may be in the form of surface mount LEDs or thru-hole mount LEDs. As can be appreciated, any other type of light source may be used without departing from the scope of the present disclosure.
[0024] FIG. 2A depicts a bottom view of the downlight auxiliary ring device 100 in the embodiment of FIG. 1A . The circular geometry of the auxiliary ring is apparent from FIG. 2A . It should be appreciated, however, that the auxiliary ring device 100 may have a non-circular geometry without departing from the scope of the present disclosure. A plurality of light sources 110 are shown, disposed at substantially equal radii from the center (e.g., from where a downlight device would be positioned at center). The light sources 110 may be of identical or different types. For instance, one different light source 110 ′ is shown in addition to a plurality of light sources 110 . The different light source 110 ′ may be different from one of the other light sources 110 in any number of ways. For example, the different light source 110 ′ may produce light of a different color (e.g., wavelength) than that produces by light sources 110 . Alternatively or additionally, different light source 110 ′ may be configured to emit light of a different brightness than light sources 110 . As still another example, different light source 110 ′ may be configured with a lens or encapsulant that conditions or shapes light differently from the other light sources 110 . In short, it should be appreciated that the downlight auxiliary ring device 100 may be configured to support light sources of the same or different types.
[0025] A power source 190 for the auxiliary ring 100 is also depicted. The power source 190 may correspond to a DC power source (e.g., battery) that provides DC current to the light sources 110 , 110 ′. In other embodiments, the power source 190 may correspond to a power conditioner that receives AC power from a grid-based power source (e.g., conventional 120V 60 hz AC power) and converts that AC power such that it can be used to drive the light sources 110 , 110 ′.
[0026] FIG. 2B depicts a cross-sectional side-view of the downlight auxiliary ring device 100 as shown in FIG. 2A as taken at section line A-A. Auxiliary ring 100 comprises flange 113 with flange upper surface 112 , first sidewall 115 , second sidewall 119 and channel 117 with channel light source mounting surface 114 . Channel 117 connects first sidewall 115 with second sidewall 119 . An adjustable shelf 180 is disposed on the channel light source mounting surface 114 . A light source 110 is disposed on the channel light source mounting surface 114 . The adjustable shelf 180 enables selectable adjustment of the orientation of light source 110 such that the light emitted from the light source may be at a selectable angle. Adjustable shelf 180 may be manually adjusted or adjusted remotely by, for example, a controller. A light diffuser 170 is attached to first sidewall 115 and second sidewall 119 . Light emitted from light source 110 passes at least partially through light diffuser 170 , therein reflecting off mounting surface 60 and or reflecting within light diffuser 170 , then continuing away from the mounting surface 60 . The light diffuser 170 diffuses, spreads out and/or scatters the light from the light source 110 , thereby providing a softer light of reduced glare. The flange 113 is at a proximal location of the auxiliary ring 100 , and the light source mounting surface 114 is at a distal location of the auxiliary ring 100 . FIG. 2B depicts one geometry of the downlight auxiliary ring device 100 in which light diffuser 170 is attached to first sidewall 115 and second sidewall 119 , thereby forming, with channel 117 , a circularly-enclosed chamber. This configuration protects light source 110 from unwelcomed foreign debris, such as dust, from contacting and/or degrading light source 110 quality. It should be appreciated, however, that the auxiliary ring device 100 may have other geometries without departing from the scope of the present disclosure. For example, the second sidewall 119 may be extended upwards such that the light diffuser 170 attaches to flange 113 and flange upper surface 112 forms a substantially planar surface with an upper surface of light diffuser 170 . In other embodiments, the geometry of the downlight auxiliary ring device 100 is as described above, except the light diffuser 170 is absent.
[0027] In one embodiment, the auxiliary ring 100 may be configured to attach to an existing downlight 20 . For example, in the embodiment of auxiliary ring 100 shown in FIGS. 2A-B , the auxiliary ring 100 could be glued onto the bottom surface of an existing downlight 20 such that the light sources 110 reflect from the attachment surface of the existing downlight 20 and thereby provide a reflected downlight.
[0028] FIG. 3 depicts a schematic-diagram representation of a controller 310 used to selectively control illumination states of the downlight 10 and auxiliary ring 100 . The auxiliary ring 100 may be configured to operate in one or more of an on state, an off state and a scalable dimmer state. Similarly, the downlight 20 may be configured to operate in one or more of an on state, an off state, and a scalable dimmer state. Controller 310 is configured to control the states of each of the auxiliary ring 100 and the downlight 20 either independently or collectively. For example, the controller 310 may provide an illumination system 10 with both auxiliary ring 100 and downlight 20 on, with only auxiliary ring 100 on, with only downlight 20 on, or with both auxiliary ring 100 and downlight 20 off. The control of downlight 20 and auxiliary ring 100 may be achieved by the controller 310 providing one or more control signals to drivers of the downlight 20 and auxiliary ring 100 , respectively. In other embodiments, the controller 310 may directly control the amount of current provided from the input power. It should also be appreciated that a common input power may be provided to both the downlight 20 and auxiliary ring 100 while in other embodiments different input powers may be provided to the illumination components.
[0029] Although the controller 310 is represented in FIG. 3 as a single element, in some embodiments the controller 310 is a plurality of controllers or sub-controllers, each controlling one or more aspects, processes or elements of the system 10 . For example, a sub-controller may control the downlight 20 while another controls auxiliary ring 100 .
[0030] While the pictorial representations and flowcharts have been discussed and illustrated in relation to a particular sequence of events, it should be appreciated that changes, additions, and omissions to this sequence can occur without materially affecting the operation of the disclosed embodiments, configuration, and aspects.
[0031] The present disclosure, in various aspects, embodiments, and/or configurations, includes components, methods, processes, systems and/or apparatus substantially as depicted and described herein, including various aspects, embodiments, configurations embodiments, sub-combinations, and/or subsets thereof. Those of skill in the art will understand how to make and use the disclosed aspects, embodiments, and/or configurations after understanding the present disclosure. The present disclosure, in various aspects, embodiments, and/or configurations, includes providing devices and processes in the absence of items not depicted and/or described herein or in various aspects, embodiments, and/or configurations hereof, including in the absence of such items as may have been used in previous devices or processes, e.g., for improving performance, achieving ease and\or reducing cost of implementation.
[0032] The foregoing discussion has been presented for purposes of illustration and description. The foregoing is not intended to limit the disclosure to the form or forms disclosed herein. In the foregoing Detailed Description for example, various features of the disclosure are grouped together in one or more aspects, embodiments, and/or configurations for the purpose of streamlining the disclosure. The features of the aspects, embodiments, and/or configurations of the disclosure may be combined in alternate aspects, embodiments, and/or configurations other than those discussed above. This method of disclosure is not to be interpreted as reflecting an intention that the claims require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed aspect, embodiment, and/or configuration. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as a separate preferred embodiment of the disclosure.
[0033] Moreover, though the description has included description of one or more aspects, embodiments, and/or configurations and certain variations and modifications, other variations, combinations, and modifications are within the scope of the disclosure, e.g., as may be within the skill and knowledge of those in the art, after understanding the present disclosure. It is intended to obtain rights which include alternative aspects, embodiments, and/or configurations to the extent permitted, including alternate, interchangeable and/or equivalent structures, functions, ranges or steps to those claimed, whether or not such alternate, interchangeable and/or equivalent structures, functions, ranges or steps are disclosed herein, and without intending to publicly dedicate any patentable subject matter.
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A downlight auxiliary ring device and method of control and use of same is disclosed. Specifically, the downlight auxiliary ring device, comprising light-emitting diodes, allows a dimmable and reduced-glare reflected downlight. It is also an aspect of the present disclosure to provide easy-to-implement and cost-effective methods of control and use of the downlight auxiliary ring device system.
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BACKGROUND OF THE INVENTION
The present invention relates to a method for the manufature of integrated electronic devices, in particular high voltage P-channel MOS transistors, and specifically for the manufacture of integrated circuits comprising a MOS transistor of the above specified type and another device having an N + region in the epitaxial layer, such as, e.g., NPN and PNP bipolar transistors, P-channel and N-channel MOS and D-MOS transistors or integrated resistors provided in N + regions.
Currently, in order to manufacture integrated circuits comprising at least one high voltage P-channel MOS transistor and another device of the specified type, a series of phases is provided to obtain at least the drain extension region of the P-channel MOS and of the N + regions of the same MOS and of the associated device. In practice, in the prior art devices, the surface is masked to allow a boron implant only at the main surface area of the device in which the drain extensions will be provided, and then again masked to perform a phosphorus implant to provide the N + regions. A subsequent thermal treatment causes diffusion of the boron and respectively of the phosphorus in the related regions as well as oxidation of the device surface.
Such a method, though currently in widespread use, is expensive because of the need to produce two different masks to obtain, respectively, the drain extension region and the additional N + regions.
SUMMARY OF THE INVENTION
The aim of the invention is therefore to provide a method for manufacturing of integrated electronic devices, in particular high voltage P-channel MOS transistors, having a smaller number of process phases.
Within the scope of this aim, a particular object of the present invention is to provide a method requiring only a mask in order to from the P - and N + regions in the epitaxial layer, thus reducing manufacture costs and times for the finished electronic device, so as to make the same device cheaper.
Another object of the present invention is to provide a method which uses single phases which are per se known in the electronics industry, and therefore can be easily performed by means of currently in use machines, which is furthermore completely reliable, and allow manufacturing of devices which are equivalent to the devices manufactured according to the known methods.
This aim, the objects mentioned and others which will become apparent hereinafter, are achieved by a method for the manufacture of integrated electronic devices, in particular high voltage P-channel MOS transistors, comprising a plurality of phases for providing an epitaxial layer which defines a main surface of the device, at least a first region with P - conductivity in said epitaxial layer and at least a second region with N + conductivity in said epitaxial layer, characterized in that to provide said first region with P - conductivity a boron implanting is performed on said main surface of the device, with no masking, and to provide said second region with N + conductivity an implanting of arsenic is performed on portions of said main surface which are preset by means of an appropriate mask, and subsequently a heat treatment phase is carried out to diffuse the implanted boron and arsenic, so that said boron and said arsenic interact in said preset portions and the arsenic inhibits the diffusion of the boron in said preset regions.
BRIEF DESCRIPTION OF THE DRAWINGS
Further characteristics and advantages of the invention will become apparent from the following description of a preferred, but not exclusive, embodiment of the method according to the invention, explained with reference to the accompanying drawings, wherein:
FIGS. 1a to 1c illustrate three successive phases for manufacturing a high voltage P-channel MOS transistor and an NPN bipolar transistor according to prior art;
FIGS. 2a and 2b show two diagrams related to the distribution of arsenic and or boron in a semiconductor, respectively after implanting and after diffusion; and
FIGS. 3a to 3d illustrate four successive phases for the manufacture of the same device of FIG. 1c, with the method according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates three successive phases in the manufacture of an integrated circuit or device comprising a high voltage P-channel MOS transistor and an NPN bipolar transistor, limited to the phases of the manufacture of the drain extension and of the N + source region of the MOS transistor on one side and of the emitter region and of the collector-enriched region of the bipolar transistor on the other.
The starting structure comprises a P-Silicon substrate indicated at 1 and an N epitaxial Silicon layer 2, including N + buried layer regions 3 and P-type isolating regions 4 which exetnd between a main surface of the integrated circuit and the substrate 1.
In this phase, the P-type base region 5 of the bipolar transistor and the P-type source 6 and drain 7 regions of the MOS transistor are already formed. Above the main surface of the circuit, an oxide layer 8 with differentiated thickness is provided, on which a masking layer 10 of photoresist has already been deposited, which layer covers all the main surface except for the area overlying the drain extension region. In FIG. 1, the arrows 11 indicate the boron implant, while the dashes 12 symbolize the boron atoms implanted in the epitaxial layer 2 in the region not covered by the mask 10.
According to the prior art method, after the boron implant, the mask is removed and a second photoresist mask (indicated in FIG. 1b with 15) is deposited to perform a phosphorus implant, schematically indicated by the arrows 16. As can be seen in FIG. 1b, during this phase the previously boron-implanted region is completely covered and the mask has window portions at the areas where the N + type regions will be formed. As a consequence, in the figure the dashes 17' indicate the phosphorus atoms for forming the emitter region of the bipolar transistor, the dashes 17" indicated the atoms which will constitute the enriched region for the collector and the dashes 17"' indicate the phosphorus atoms which will constitute the enriched region for the body contact of the MOS transistor. In this figure, 7' indicates the thin regions in which there is an accumulation of boron atoms which will constitute the drain extensions.
According to the prior art, then the second photoresist mask is completely removed, and a thermal process is carried out to diffuse the implanted boron and phosphorus atoms. This phase, as is pointed out in FIG. 1c, causes formation of the emitter region 20 of the bipolar transistor, of the enriched collector region 21 of the bipolar transistor, of the N + enrichment region 22 for the body contact of the MOS transistor and of the P - drain extension regions 7" of the MOS transistor.
As can be seen, the method according to the prior art therefore requires two lithographic processes to obtain the two separate masks for boron and phosphorus implanting.
According to the invention, on the contrary, the regions with N + type conductivity and of the region with P - type conductivity are formed by meanas of a single mask, exploiting the different behavior of boron when interacting with arsenic, which can be used to obtain the N + regions in the place of phosphorus. Such behavior is illustrated in the two diagrams of FIG. 2 which depict the distribution of arsenic and boron atoms inside a semiconductor layer respectively after implant and after diffusion by thermal treatment. In paraticular, in the case of an implant causing a distribution of arsenic and of boron as illustrated in FIG. 2a, after the subsequent thermal treatment, arsenic has the distribution as illustrated in the single curve of FIG. 2b, and boron has a distribution depending on arsenic having been implanted or not in the same region. In particular, the broken curve B I illustrates the distribution of boron in a semiconductor layer in which arsenic has not also been implanted, while the continuous curve B II indicates the distribution of boron after the diffusion if arsenic has also been implanted in the same region. As can be seen, arsenic constitutes, in practice, an inhibitor to the diffusion of boron, so that in practice, in all the implanted regions, the behavior is dominated by the arsenic atoms implant. This behavior is employed in the method according to the invention, so as to eliminate the prior art masking and associated lithographic processes for performing a boron implant. In practice, according to the invention, a boron implant is performed over all the main surface of the device, and only the regions to be formed with N + conductivity are implanted with arsenic thus inhibiting diffusion of the implanted boron, finaly giving regions with N + type conductivity.
An example of the method for the manufacture of an integrated circuit similar to the one of FIG. 1, but with the method according to the invention, is described with reference to FIG. 3, which illustrates four successive steps of the method according to the invention. Also in this case, only the steps related to the production of the regions with N + and P - conductivity inside the epitaxial layer are described, omitting the preceding phases, carried out according to the prior art techniques for obtaining the same starting structure as illustrated in FIG. 1a. Consequently, the same parts have been referenced with the same reference numerals.
Thus, FIG. 3a shows a structure comprising a substrate 1, an epitaxial layer 2, buried layers 3 and insolating layers 4. This structure furthermore comprises the base region 5 of the bipolar transistor and the P-type source 6 and drain 7 regions of the MOS transistor. On the main upper surface of the device, an oxide layer 8 with differentiated thickness is applied, and the gate region 9 of the N-MOS transistor has already been formed. At this stage, boron implant (symbolized in FIG. 3a by the arrows 25) is performed, which leads to accumulation of boron atoms on the main surface of the integrated circuit or device in the reduced thickness regions of the oxide layer 8, as schematically illustrated by the dashes 26 in the base region 5, by the dashes 26' in the collector region, where the enriched N + type region will be formed, by the dashes 26" where the enriched body region will be formed and inside the source layer 6 of the MOS transistor and finally by the dashes 26"' adjacent to the drain region 7 to provide the drain extension region.
At the end of the boron implant, a single masking is performed, including deposition of a photoresist layer 27 on preset portions of the main surface of the integrated circuit, where the arsenic is not to be implanted. In particular, the region where the drain extensions will be provided is covered. Then, as symbolized in FIG. 3b by the arrows 28, arsenic is implanted, causing accumulation of arsenic atoms in the unprotected regions, as illustrated in the figure by the dashes 31 (where the emitter of the bipolar transistor will be formed), by the dashes 32 (where the enriched collector region will be formed), and by the dashes 33 (to form the enriched body contact region of the MOS transistor). In this figure, the regions 29, 30, and 7', having a concentration of boron atoms due to the previous implant, are also indicated schematically.
The subsequent phases of the process occur in a known manner and lead to the manufacture of a conventional structure, as is illustrated in FIGS. 3c and 3d. Indeed, at the end of arsenic implant, according to the current art, the mask is removed and a thermal process is performed to diffuse the implanted atoms, as well as to oxidize the main surface of the device. Consequently, by virtue of the interaction of arsenic and boron atoms, and in particular the inhibition effected by the former ones onto the latter ones, in spite of the boron implant, a region 35 of the N + type, which constitutes the emitter of the bipolar transistor, a region 36 of the N + type, which forms the enriched collector zone of the same transistor, a region 37 of the N + body contact type of the MOS transistor and of the regions 7" of the P - drain extension regions of the MOS transistor are formed. Furthermore, the oxide layer 38 is formed on the entire main upper surface of the device. Then usual phases are carried out to obtain oxide portions 40 through chemical etching from the layer 38, second oxide layer portions 41 through vapor-phase chemical deposition, and base 42, emitter 43, and collector 44 metalizations of the bipolar transistor and source 45 and drain 46 metalization of the MOS transistor to provide the contacts with the respective electrodes as illustrated in the figure.
As can be seen from the above description, the invention fully achieves the intended aims. Indeed, a method has been disclosed which allows manufacture of regions with N + -and P - conductivity with a smaller number of phases than prior methods, in particular through the elimination of a lithographic process, with a consequent reduction in manufacturing times and costs of the finished product.
The method described above is therefore simpler than the known ones, though it comprises phases which are per se known in the industry for the manufacture of electronic devices and therefore can be achieved with currently available machines.
The invention thus conceived is susceptible to numerous modifications and variations, all of which are within the scope of the inventive concept. In particular, the method according to the invention can be used for the manufacture even only of high voltage P-channel MOS transistors to form channel and source extension regions, or to produce, in a single integrated circuit, a high voltage P-channel MOS transistor and other devices, such as, e.g., PNP bipolar transistors, N-channel and P-channel MOS and D-MOS transistors, as well as to manufacture integrated resistors formed by an N + layer. Furthermore, though it is preferred to perform the boron implant phase first and then the arsenic implant phase, the two phases can be exchanged for each other, achieving the same results.
Furthermore, all the details may be replaced by other technically equivalent ones.
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This method, requiring a smaller number of masking steps with respect to the known methods, comprises boron implant on the surface of an epitaxial layer, without masking, and arsenic implant in predetermined locations of the epitaxial layer surface by means of an appropriate mask. A subsequent thermal treatment then leads to diffusion of the implanted arsenic and boron atoms, but boron diffusion in the regions in which arsenic implant has also occurred is prevented by the interaction with the latter, to thereby obtain regions with an N + type conductivity where both boron and arsenic have been implanted and regions of P type conductivity where only boron has been implanted.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a fabric tensioning device for stretching work fabric in the sewing location of a sewing machine.
2. Description of Related Art
Devices for tensioning a piece of tube-like fabric, such as a material for socks and wrist bands, using a cylindrical frame are used in embroidering on a sewing machine. One of such fabric tensioning device is disclosed in International Patent Publication Number WO0/53836. This device has a cylindrical frame 101 that is placed to cover the outside of the cylinder bed (not shown) of the sewing machine as shown in FIG. 11. A sewing window 102 is formed in cylindrical frame 101 for exposing the sewing, area of the cylinder bed. A fabric clamping member 103 capable of opening and closing vertically is provided in order to clamp down the fabric, which is arranged to cover sewing window 102 , against cylindrical frame 101 . Fabric clamping member 103 is formed by bending a steel rod to form a rectangular shape with a closed front end, to clamp down the fabric against cylindrical frame 101 to hold it on three sides, i.e., the front, left and right sides, of the sewing area.
However, with this fabric tensioning device, because fabric clamping member 103 is a frame-like member made of a highly rigid material, the contact of fabric clamping member 103 against the fabric is often localized. This causes a clamp mark in a certain area, and insufficient clamping in other areas of the fabric, which are all undesirable. Moreover, since fabric clamping member 103 does not hold the fabric on the rear side of the sewing area, it may cause looseness in the fabric on the left and right sides of the sewing area particularly when the fabric is a thin or slippery piece of processed fabric, thus affecting the sewing accuracy.
SUMMARY OF THE INVENTION
The present invention provides a fabric tensioning device for a sewing machine that can solve the abovementioned problems by holding down the fabric on the four sides of the sewing area evenly and stretching the fabric securely on the cylindrical frame without causing any clamping marks or slacks.
In order to solve the abovementioned problems, the fabric tensioning device according to the present invention comprises a cylindrical frame having a sewing window and a fabric clamping member for clamping down against said cylindrical frame a work fabric that is covering said sewing window, wherein said fabric clamping member is provided in such a way as to be able to open or close against said cylindrical frame, and said fabric clamping member is equipped with a pair of fabric clamps on the left and right hand side that are oblong in the longitudinal direction having open-end front edges, wherein said fabric clamps are tightened against said cylindrical frame at the front and rear ends of a sewing area by means of a pair of belts provided in the front and the rear of the area.
While the direction that the fabric clamping member opens or closes can either be a vertical direction or a lateral direction, it is preferable for the fabric clamping member to be mounted in such a way to open or close in the lateral direction as it makes it easier to open the sewing window fully and to spread the fabric over the area. It is preferable in this case that the fabric clamping member is pivot-mounted on the cylindrical frame at a location outside of one of the fabric clamps so that a wide space can be formed between the fabric clamp and the cylindrical frame and the work fabric can be easily inserted. More specifically, it is preferable to form the fabric clamping member in a rectangular shape with an open-ended front edge by connecting the rear end of the left and right hand side fabric clamps, and to attach the rear end of the fabric clamping member to the cylindrical frame via a pivot shaft located outside of one of the fabric clamps so that the fabric clamping member can be opened in the lateral direction.
The belts that tighten the fabric clamps do not have to be made of a specific kind of material; for example, rubber belts, fabric belts, surface fastener belts, etc., can be used, as long as they are flexible so that they are unlikely to leave clamping marks. Surface fastener belts with open-ends are preferable as they can be used to tighten the fabric clamps with one-touch operation. It is preferable in this case to provide a surface fastener on one of the fabric clamps in such a way that the position of the rear belt can be adjusted in the forward and backward direction in order to be able to tighten the fabric clamp close to the rear end of the stitch forming area as needed in accordance with the sewing area of an embroidery pattern, etc. The front belt should preferably be threaded through the hole provided on the front end of the left and right fabric clamps so that it will not be lost.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a cylinder bed according to an embodiment of the invention.
FIG. 2 is a front view of the bed according to an embodiment of the invention.
FIG. 3 is a disassembled perspective view showing a cylindrical frame guide device provided on the bed according to an embodiment of the invention.
FIG. 4 is a perspective view of a fabric tensioning device of the bed according to an embodiment of the invention.
FIG. 5 is a side view of the fabric tensioning device according to an embodiment of the invention.
FIG. 6 is a partially broken front view of the fabric tensioning device according to an embodiment of the invention.
FIG. 7 is a plan view of the fabric tensioning device according to an embodiment of the invention.
FIG. 8 is a cross-sectional view showing how an core material and a work fabric are mounted on the fabric tensioning device according to an embodiment of the invention.
FIG. 9 is a plan view showing how the core material and the work fabric are tensioned according to an embodiment of the invention.
FIG. 10 is a cross-sectional view showing how the core material and the work fabric are tensioned according to an embodiment of the invention.
FIG. 11 is a perspective view of a fabric tensioning device of the prior art.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment of the invention on an embroidering sewing machine will be described below with reference to the accompanying drawings. As shown in FIG. 1 and FIG. 2, a head 1 and a cylinder bed 2 are displaced in a vertical direction in the machine frame (not shown) of a the sewing machine, and a needle 3 is attached to the bottom end of head 1 , while a bobbin case 4 and a needle plate 11 are provided at the front end of cylinder bed 2 . A Y-direction moving body 5 is supported by the top surface of cylinder bed 2 , and a base plate 6 is connected vertically to moving body 5 . Three rollers 8 are displaced on the front side of base plate 6 in order to support a drive ring 7 , while two guide rollers 10 are provided on the back side of base plate 6 engaging with two bottom grooves 9 on the left and right sides of cylinder bed 2 .
An X-direction moving body 13 is supported via a rail 12 provided on the top of Y-direction moving body 5 , while a pulley 14 is provided at the left and right ends of moving body 13 respectively. A wire rope 15 is provided on pulleys 14 tightly stretched by means of a spring 16 , while rope 15 is wrapped around drive ring 7 in the middle. Y-direction moving body 5 and X-direction moving body 13 are connected to a sewing frame driving device (not shown) of the sewing machine, and Y-direction moving body 5 strokes drive ring 7 in a reciprocating manner in the axial direction (front and rear direction) of cylinder bed 2 via base pate 6 , while X-direction moving body 13 rotates drive ring 7 in a reciprocating manner around the axis of cylinder head 2 via wire rope 15 .
In an embroidering process of a piece of tube-like fabric such as a material for socks and wrist bands, a cylindrical frame 19 of fabric tensioning device 18 is placed to cover the outside of cylinder bed 2 and is attached to drive ring 7 via a mounting part 19 a at its rear end. A latching piece 20 and a flange 21 are provided protrusively on the rear outer periphery of cylindrical frame 19 (see FIG. 4 ), while a lever 22 that engages with latching piece 20 and a spring 23 that elastically contacts with flange 21 are provided on drive ring 7 . Thus, cylindrical frame 19 is connected tightly to drive ring 7 via lever 22 and spring 23 and driven together with drive ring 7 in the axial and circumferential directions relative to the axis of cylinder bed 2 in order to sew on the fabric stretched around cylindrical frame 19 in the cooperation of needle 3 and bobbin case 4 .
As shown in FIG. 3, a pair of arms 25 is protrusively provided on the left and right sides of the front end of cylinder bed 2 and a needle plate 11 is horizontally affixed on arms 25 . Curved surfaces 11 a are formed on the left and right shoulder areas of needle plate 11 close to the inner surface of cylindrical frame 19 , and a boss 26 equipped with a needle hole 26 a is provided protruding low in the center flat area of needle plate 11 . An opening 29 is formed below needle plate 11 , the front end of a bobbin case drive shaft 31 extends into this opening 29 , and bobbin case 4 is mounted on bobbin case drive shaft 31 .
Also, a guide member 27 is provided in opening 29 for supporting cylindrical frame 19 from the inside. Guide member 27 consists of a connecting part 27 a in the rear end and two side wall parts 27 b on the left and right sides, together forming a rectangular shape, and connecting part 27 a is detachably affixed with a screw 32 to the front end surface of cylinder bed 2 below bobbin case drive shaft 31 as side walls 27 b are placed to cover the outside of the arms 25 . A curved plate 33 is affixed by welding on the outside of each side wall part 27 b, and these curved plates 33 form a partial cylindrical surface 30 that contacts concentrically with the inside of cylindrical frame 19 for side wall parts 27 b.
A protection cover 28 is provided below guide member 27 and cover 28 covers bobbin case 4 from its underside. Protection cover 28 consists of flat parts 28 a and a curved part 28 b forming a U-shape as it is viewed from the front, wherein curved part 28 b forms a partial cylindrical surface 36 having the same curvature as partial cylindrical surface 30 of guiding member 27 for cover 28 . Semispherical protrusions 34 are provided on flat parts 28 a, while holes 35 are provided on side walls 27 a to fit with protrusions 34 . Protection cover 28 is mounted detachably on guide member 27 by means of fitting between protrusions 34 and holes 35 as flat parts 28 a are inserted on the inside of side wall parts 27 b.
As shown in FIG. 4 through FIG. 7, cylindrical frame 19 comprises a sewing window 37 that exposes needle plate 11 , an core material clamping member 38 that clamps down the core material C (see FIG. 7) covering sewing window 37 against cylindrical frame 19 , a fabric clamping member 39 that clamps down the work fabric W that is covering the core material C together with the core material C against cylindrical frame 19 , and a support member 40 that supports the core material C and the work fabric W in the middle position of sewing window 37 . The core material C is a shape keeping material to prevent the work fabric W from sinking and is made of cardboard, unwoven fabric, etc. If the work fabric W consists of a rigid material such as leather and felt, it is possible to sew by stretching the work fabric W direction over cylindrical frame 19 without using the core material C.
Sewing window 37 is formed to a length corresponding to the axial stroke length of cylindrical frame 19 , while a slip guard 42 made of rubber is glued on cylindrical frame 19 along the front and rear edges of sewing window 37 respectively and a tightener 43 made of strip steel or rubber is protrusively provided along the left and right side edges of sewing window 37 . Support member 40 is formed into a curved shape having a curvature approximately equal to that of the outside diameter of cylindrical frame 19 and is fastened at fastening areas 40 a at each end with screws 44 that are screwed onto screw holes 43 a of tighteners 43 in an axially adjustable manner spanning over sewing window 37 . A notch 45 is formed on rear mounting part 19 a of cylindrical frame 19 to allow spring 23 of drive ring 7 to enter. The inside of the front end of cylindrical frame 19 is attached with an annular plate 46 , at a portion of which is provided with a protruding positive stop 47 for positioning the core C from the front end.
Core material clamping member 38 made of a steel strip is formed in an oblong shape in the axial direction (longer than sewing window 37 ) on the left and right hand sides of cylindrical frame 19 respectively under tightener 43 . The rear end of core material clamping member 38 is affixed to flange 21 with a screw 49 on the left and right sides of cylindrical frame 19 respectively, while the front end of core material clamping member 38 is provided in such a way as to be able to open individually to the left and right relative to cylindrical frame 19 . At multiple places inside of core material clamping member 38 , clamping pieces 50 are provided, which are formed being bent in an angle going from top to bottom for elastically contacting the core material C. At the front end of core material clamping member 38 , temporary latches 51 are formed bending them inward, in such a way that temporary latches 51 can elastically engage with annular plate 46 through notches 52 provided on cylindrical frame 19 in order to hold core material clamping member 38 temporarily in a closed state.
Fabric clamping member 39 comprises, provided on the left and right sides, a pair of fabric clamps 56 that are oblong in the axial direction and open at the front end. The rear ends of the left and right fabric clamps 56 are connected by a connecting part 55 thus causing fabric clamping member 39 to have substantially a rectangular shape with an open ended front. Fabric clamps 56 are each made of a steel strip and to a length approximately equal to that of core material clamping member 38 and are facing core material clamping member 38 from the outside. Slip guards 53 made of rubber plates with grooves that are intended to sandwich the work fabric W with fabric clamps 56 are glued on the outside of core material clamping member 38 . Connecting part 55 is made of a steel plate in a shape to go across cylindrical frame 19 , and a bracket 57 is attached to its left side. A threaded shaft 58 is provided on bracket 57 on the outside of the left fabric clamp 56 , and fabric clamping member 39 is fastened to flange 21 of cylindrical frame 19 by means of threaded shaft 58 in such a way that it can open or close in the lateral (left and right) direction.
An oblong surface fastener tape 60 is adhered to the outside surface of each fabric clamp 56 and a surface fastener belt 61 with open ends are latched to this tape 60 in such a way as to be adjustable in the axial direction in order to coordinate with support member 40 . An engaging hole 62 is provided at the front end of the left and right fabric clamps 56 and a surface fastener belt 63 is threaded through engaging hole 62 . The left and right fabric clamps 56 and the left and right core material clamping members 38 can be tightened against cylindrical frame 19 in the front and rear of needle plate 11 where the sewing actions occur by means of the front and rear fastener belts 61 and 63 . Surface fastener belts 61 and 63 can be provided with surface fasteners for the entire surface on the front and back or can be provided only on both ends.
The method of using fabric tensioning device 18 in a sewing machine constituted as described in the above will be described as follows: In embroidering a piece of tube-like fabric, as shown in FIG. 1, set cylindrical frame 19 to cover the outside of cylinder bed 2 , fit mounting area 19 a into drive ring 7 , clamp flange 21 to spring 23 , cause lever 22 to engage with engaging piece 20 , and mount cylindrical frame 19 tightly on drive ring 7 .
Next, as shown in FIG. 7 and FIG. 8, move open fabric clamping member 39 toward left side of cylindrical frame 19 , and make the core material C to abut against positive stop 47 , to be supported by supporting member 40 , to cover sewing window 37 , and to be clamped down against cylindrical frame 19 to be stretched by means of core material clamping members 38 on the left and right sides. According to fabric tensioning device 18 of this embodiment, the following operating advantages can be achieved:
(1) Since two core material clamping members 38 on the left and right sides are attached to cylindrical frame 19 in such a way as to be able to open independently, it is possible to clamp down the core material C against cylindrical frame 19 on the left and right side independently and align it against the outer periphery of cylindrical frame 19 easily and accurately. More specifically, after clamping the left side of the core material with the left core material clamping member 38 , adjust the shape of the remaining portion of the core material C, and clamp the right side of the core material with the right core material clamping member 38 to stretch the entire core material C in a smooth cylindrical shape; the order can be reversed to start with the right side as well.
(2) Since the front ends of the left and right side core material clamping members 38 are arranged in such a way as to be able to open toward the left and right sides of cylindrical frame 19 respectively, in contrast to the prior art wherein the clamping member opened and closed in the vertical direction, the core material C is less likely to be stretched in a skewed manner and the material can be easily stretched against cylindrical frame 19 evenly from the front to the rear at the same height.
(3) Since temporary latches 51 are provided at the front end of core material clamping member 38 , the core material C can be held in a smooth cylindrical shape by temporarily latching one side of the core material C, which makes it easy to adjust the other side of the work fabric W with both hands and to stretch it out neatly.
(4) Since the core material clamping members 38 are provided below tighteners 43 , it is possible to securely prevent the core material C from slacking and deformation while it is temporarily latched.
(5) Since multiple clamping pieces 50 are provided in the inside of core material clamping members 38 , it is possible to hold various parts of the core material C with an even force using core material clamping members 38 which are oblong in the axial direction.
Next, place the work fabric W on top of the core material C as shown in FIG. 9 and FIG. 10, close down fabric clamping member 39 , and clamp down the work fabric W via the core material C against cylindrical frame 19 with the left and right fabric clamps 56 . Next, make both ends of the front and rear surface fastener belts 61 and 63 contact and stick together, and tighten them in order to cause fabric clamps 56 to tighten against cylindrical frame 19 together with core material clamping members 38 to stretch the work fabric W against cylindrical frame 19 . According to fabric tensioning device 18 of this embodiment, the following operating advantages can be achieved:
(6) Since the two fabric clamps 56 on the left and right sides are tightened against cylindrical frame 19 by means of two surface fastener belts 61 and 63 in the front and rear, the work fabric W is evenly clamped down on four sides of needle plate 11 thus making it possible to stretch it out securely on cylindrical frame 19 without causing any clamp marks or slacks.
(7) Since fabric clamping member 39 is provided in such a way as to be able to open or close in the lateral direction, the core material C and the work fabric W can be neatly and quickly spread out to cover the fully exposed sewing window 37 (see FIG. 7 ).
(8) Since fabric clamping member 39 is pivot mounted on flange 21 via threaded shaft 58 located on the outside of the left side fabric clamp 56 , it is possible to provide a wide space between the left side fabric clamp 56 and cylindrical frame 19 when fabric clamping member 39 is opened, allowing the core material C and the work fabric W to be inserted in that space easily. (See FIG. 8)
(9) Since the left and right fabric clamps 56 are facing the left and right core material clamping members 38 from the outside, they can be tightened together with two surface fastener belts 61 and 63 to hold the work fabric W and the core material C against cylindrical frame 19 solidly and simultaneously.
(10) Since the slip guards 53 are provided on the outside surfaces of the core material clamping members 38 , the work fabric W can be clamped without any slacks between core materials clamping members 38 and fabric clamps 56 .
(11) Since surface fastener belts 61 and 63 having open ends on one side are used, fabric clamps 56 can be tightened by one-touch operation without causing any slacks.
(12) Since the rear surface fastener belt 61 is engaged with surface fastener tape 60 in such a way as to be adjustable in the axial direction, it is possible to tighten fabric clamps 56 closer to the back of the embroidering position as needed according to the embroidering pattern.
(13) Since the front surface fastener belt 63 is threaded through engaging hole 62 of fabric clamp 56 , this belt 63 is less likely to get lost.
According to a sewing machine of this embodiment, the following operating advantages can be achieved:
(14) Since cylindrical frame 19 is guided by means of guide member 27 , which is independent of needle plate 11 , it is possible to install needle plate 11 permanently on cylinder bed 2 in order to use it not only for cylindrical frame 19 but also to other type of frames such as a rectangular frame and an annular frame, thus eliminating the needs of replacing needle plate 11 on different applications.
(15) Since curved surfaces 11 a are provided on the left and right shoulder areas of needle plate 11 facing the inner surface of cylindrical frame 19 in close ranges, it is possible to feed the work fabric W smoothly without being stuck on needle plate 11 and to provide a wide area on needle plate 11 for supporting the work fabric.
(16) Since partial cylindrical surface 30 is formed on the left and right side walls 27 b of guide member 27 concentric with cylindrical frame 19 in a close range, cylindrical frame 19 can be guided in parallel with cylinder bed 2 in high precision.
(17) Since guide member 27 is formed in a open-ended rectangular shape, it is possible to attach guide member 27 rigidly on cylinder bed 2 via its connecting part 27 a, thus effectively preventing vibration.
(18) Since partial cylindrical surface 30 is formed on the left and right side A walls 27 b, it is possible to install bobbin case 4 and form a wide area of partial cylindrical surface 30 effectively using the limited space underneath needle plate 11 effectively.
(19) Since protection cover 28 is provided detachably on guide member 27 , bobbin cage 4 is not exposed and makes it safer when cylindrical frame 19 is not used, while the bobbin case 4 can be easily removed or installed by removing cover 28 during the bobbin exchange.
(20) Since partial cylindrical surface 36 is formed on protection cover 28 , this guide surface 36 provides a wide surface for guiding cylindrical frame 19 in cooperation with partial cylindrical surface 30 of guide surface 27 .
This invention should not be construed to be restricted with the embodiment described above, but rather can be materialized in various other ways without leaving the gist of the invention as exemplified below:
(a) To pivot-mount fabric clamping member 39 by a shaft at the rear end so that it can open or close vertically;
(b) To form the entire structure of fabric clamping member 39 with a rod material in an open-ended rectangular shape;
(c) To form a slit oblong in the axial direction in one of fabric clamps 56 of fabric clamping member 39 , and cause the rear belt 61 to be engaged with this slit in such a way as to make its position adjustable;
(d) To form core material clamping member 38 with a rod material in a shape oblong in the axial direction;
(e) To support core material clamping member 38 at its rear end via a shaft and spring mechanism rotating relative to cylindrical frame 19 .
(f) To provide core material clamping member 38 and fabric clamps 56 in positions vertically separated on both left and right sides of cylindrical frame 19 ; and
(g) To form a portion of the guide device for cylindrical frame 19 that corresponds to protection cover 28 integral with guide member 27 and provide on the outside of guide member 27 a partial cylindrical surface with an open portion at the top like a C-shape.
As can be seen from the above, the fabric tensioning device for a sewing machine according to this invention, the two fabric clamps on the left and right sides of the fabric clamping member are tightened against the cylindrical frame with two belts at the front and rear sides thereof, so that the work fabric can be clamped on four sides of the sewing area, providing an excellent result in securely tensioning the fabric on the circular frame causing no clamping marks or slacks.
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The present invention provides a fabric tensioning device for stretching fabric on a sewing machine. The fabric tensioning device includes a cylindrical frame having a window extending in a longitudinal direction. A fabric clamping member clamps down the cloth material against the frame for presenting the material to the embroidery needle at the window in a tensioned state. The clamping member opens and closes on the frame and has a pair of opposing fabric clamps on the left and right side of the frame that are oblong in the longitudinal direction with open front edges. The fabric clamps are tightened against the frame by belts in the front and rear thereof.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 12/113,262, filed May 1, 2008; which is a continuation of U.S. application Ser. No. 11/093,152, filed Mar. 29, 2005. This application relates to commonly-owned, co-pending U.S. patent application Ser. Nos. 11/093,132; 11/093,154; 11/093,131; 11/093,132; 11/093,127; and 11/093,160 all filed on even date herewith and incorporated by reference as if fully set forth herein.
BACKGROUND
1. Field
The present invention generally relates to computer systems having multiprocessor architectures and, more particularly, to a novel multi-processor computer system for processing memory accesses requests and the implementation of cache coherence in such multiprocessor systems.
2. Description of the Prior Art
To achieve high performance computing, multiple individual processors have been interconnected to form multiprocessor computer system capable of parallel processing. Multiple processors can be placed on a single chip, or several chips—each containing one or several processors—interconnected into a multiprocessor computer system.
Processors in a multiprocessor computer system use private cache memories because of their short access time (a cache is local to a processor and provides fast access to data) and to reduce number of memory requests to the main memory. However, managing caches in multiprocessor system is complex. Multiple private caches introduce the multi-cache coherency problem (or stale data problem) due to multiple copies of main memory data that can concurrently exist in the multiprocessor system.
Small scale shared memory multiprocessing system have processors (or groups thereof) interconnected by a single bus. However, with the increasing speed of processors, the feasible number of processors which can share the bus effectively decreases.
The protocols that maintain the coherence between multiple processors are called cache coherence protocols. Cache coherence protocols track any sharing of data block between the processors. Depending upon how data sharing is tracked, cache coherence protocols can be grouped into two classes: 1) Directory based and 2) Snooping.
In directory based approach, the sharing status of a block of physical memory is kept in just one location called the coherency directory. Coherency directories are generally large blocks of memory which keep track of which processor in the multiprocessor computer system owns which lines of memory. Disadvantageously, coherency directories are typically large and slow. They can severely degrade overall system performance since they introduce additional latency for every memory access request by requiring that each access to the memory go through the common directory.
FIG. 1 illustrates a typical prior art multiprocessor system 10 using the coherence directory approach for cache coherency. The multiprocessor system 10 includes a number of processors 15 a, . . . , 15 d interconnected via a shared bus 24 to the main memory 20 a, 20 b via memory controllers 22 a, 22 b, respectively. Each processor 15 a, . . . , 15 d has its own private cache 17 a, . . . , 17 d, respectively, which is N-way set associative. Each request to the memory from a processor is placed on the processor bus 24 and directed to the coherency directory 26 . Frequently, in the coherency controller, a module is contained which tracks the location of cache lines held in particular subsystems to eliminated the need to broadcast unneeded snoop request to all caching agents. This unit is frequently labeled “snoop controller” or “snoop filter”. All memory access requests from the I/O subsystem 28 are also directed to the coherency controller 26 . Instead of the main memory, secondary cache connected to the main memory can be used. Processors can be grouped into processor clusters, where each cluster has its own cluster bus, which is then connected to the coherency controller 26 . As each memory request goes through the coherence directory, additional cycles are added to each request for checking the status of the requested memory block.
In a snooping approach, no centralized state is kept, but rather each cache keeps the sharing status of data block locally. The caches are usually on a shared memory bus, and all cache controllers snoop (monitor) the bus to determine whether they have a copy of the data block requested. A commonly used snooping method is the “write-invalidate” protocol. In this protocol, a processor ensures that it has exclusive access to data before it writes that data. On each write, all other copies of the data in all other caches are invalidated. If two or more processors attempt to write the same data simultaneously, only one of them wins the race, causing the other processors' copies to be invalidated.
To perform a write in a write-invalidate protocol based system, a processor acquires the shared bus, and broadcasts the address to be invalidated on the bus. All processors snoop on the bus, and check to see if the data is in their cache. If so, these data are invalidated. Thus, use of the shared bus enforces write serialization.
Disadvantageously, every bus transaction in the snooping apporach has to check the cache address tags, which could interfere with CPU cache accesses. In most recent architectures, this is typically reduced by duplicating the address tags, so that the CPU and the snooping requests may proceed in parallel. An alternative approach is to employ a multilevel cache with inclusion, so that every entry in the primary cache is duplicated in the lower level cache. Then, snoop activity is performed at the secondary level cache and does not interfere with the CPU activity.
FIG. 2 illustrates a typical prior art multiprocessor system 50 using the snooping approach for cache coherency. The multiprocessor system 50 contains number of processors 52 a, . . . , 52 c interconnected via a shared bus 56 to the main memory 58 . Each processor 52 a, . . . , 52 c has its own private cache 54 a, . . . , 54 c which is N-way set associative. Each write request to the memory from a processor is placed on the processor bus 56 . All processors snoop on the bus, and check their caches to see if the address written to is also located in their caches. If so, the data corresponding to this address are invalidated. Several multiprocessor systems add a module locally to each processor to track if a cache line to be invalidated is held in the particular cache, thus effectively reducing the local snooping activity. This unit is frequently labeled “snoop filter”. Instead of the main memory, secondary cache connected to the main memory can be used.
With the increasing number of processors on a bus, snooping activity increases as well. Unnecessary snoop requests to a cache can degrade processor performance, and each snoop requests accessing the cache directory consumes power. In addition, duplicating the cache directory for every processor to support snooping activity significantly increases the size of the chip. This is especially important for systems on a single chip with a limited power budget.
What now follows is a description of prior art references that address the various problems of conventional snooping approaches found in multiprocessor systems.
Particularly, U.S. Patent Application US2003/0135696A1 and U.S. Pat. No. 6,704,845B2 both describe replacement policy methods for replacing entries in the snoop filter for a coherence directory based approach including a snoop filter. The snoop filter contains information on cached memory blocks—where the cache line is cached and its status. The U.S. Patent Application US2004/0003184A1 describes a snoop filter containing sub-snoop filters for recording even and odd address lines which record local cache lines accessed by remote nodes (sub-filters use same filtering approach). Each of these disclosures do not teach or suggest a system and method for locally reducing the number of snoop requests presented to each cache in a multiprocessor system. Nor do they teach or suggest coupling several snoop filters with various filtering methods, nor do they teach or suggest providing point-to-point interconnection of snooping information to caches.
U.S. Patent Applications US2003/0070016A1 and US2003/0065843A1 describe a multi-processor system with a central coherency directory containing a snoop filter. The snoop filter described in these applications reduces the number of cycles to process a snoop request, however, does not reduce the number of snoop requests presented to a cache.
U.S. Pat. No. 5,966,729 describes a multi-processor system sharing a bus using a snooping approach for cache coherence and a snoop filter associated locally to each processor group. To reduce snooping activity, a list of remote processor groups “interested” and “not-interested” in particular cache line is kept. Snoop requests are forwarded only to the processor groups marked as “interested” thus reducing the number of broadcasted snoop requests. It does not describe how to reduce the number of snoop requests to a local processor, but rather how to reduce the number of snoop requests sent to other processor groups marked as “not interested”. This solution requires keeping a list with information on interested groups for each line in the cache for a processor group, which is comparable in size to duplicating the cache directories of each processor in the processor group thus significantly increasing the size of chip.
U.S. Pat. No. 6,389,517B1 describes a method for snooping cache coherence to allow for concurrent access on the cache from both the processor and the snoop accesses having two access queues. The embodiment disclosed is directed to a shared bus configuration. It does not describe a method for reducing the number of snoop requests presented to the cache.
U.S. Pat. No. 5,572,701 describes a bus-based snoop method for reducing the interference of a low speed bus to a high speed bus and processor. The snoop bus control unit buffers addresses and data from the low speed bus until the processor releases the high speed bus. Then it transfers data and invalidates the corresponding lines in the cache. This disclosure does not describe a multiprocessor system where all components communicate via a high-speed bus.
A. Moshovos, G. Memik, B. Falsafi and A. Choudhary, in a reference entitled “JETTY: filtering snoops for reduced energy consumption in SMP servers” (“Jetty”) describe several proposals for reducing snoop requests using hardware filter. It describes the multiprocessor system where snoop requests are distributed via a shared system bus. To reduce the number of snoop requests presented to a processor, one or several various snoop filters are used.
However, the system described in Jetty has significant limitations as to performance, supported system and more specifically interconnect architectures, and lack of support for multiporting. More specifically, the approach described in Jetty is based on a shared system bus which established a common event ordering across the system. While such global time ordering is desirable to simplify the filter architecture, it limited the possible system configurations to those with a single shared bus. Alas, shared bus systems are known to be limited in scalability due to contention to the single global resource. In addition, global buses tend to be slow, due to the high load of multiple components attached to them, and inefficient to place in chip multiprocessors.
Thus, in a highly optimized high-bandwidth system, it is desirable to provide alternate system architectures, such as star, or point-to-point implementations. These are advantageous, as they only have a single sender and transmitter, reducing the load, allowing the use of high speed protocols, and simplifying floor planning in chip multiprocessors. Using point to point protocols also allows to have several transmissions in-progress simultaneously, thereby increasing the data transfer parallelism and overall data throughput.
Other limitations of Jetty include the inability to perform snoop filtering on several requests simultaneously, as in Jetty, simultaneous snoop requests from several processors have to be serialized by the system bus. Allowing the processing of several snoop requests concurrently would provide a significant increase in the number of requests which can be handled at any one time, and thus increase overall system performance.
Having set forth the limitations of the prior art, it is clear that what is required is a system incorporating snoop filters to increase overall performance and power efficiency without limiting the system design options, and more specifically, methods and apparatus to support snoop filtering in systems not requiring a common bus.
Furthermore, there is a need for a snoop filter architecture supporting systems using point-to-point connections to allow the implementation of high performance systems using snoop filtering.
There is a further need for the simultaneous operation of multiple snoop filter units to concurrently filter requests from multiple memory writers to increase system performance.
There is further a need to provide novel, high performance snoop filters which can be implemented in a pipelined fashion to enable high system clock speeds in systems utilizing such snoop filters.
There is an additional need for snoop filters with high filtering efficiency transcending the limitations of prior art.
SUMMARY
It is therefore an object of the present invention to provide a simple method and apparatus for reducing the number of snoop requests presented to a single processor in cache coherent multiprocessor systems.
It is a further object of the present invention to provide a simple method and apparatus for supporting snoop filtering in multiprocessor system architectures. While prior art has allowed snoop filtering to be used only in bus-based system, the present invention teaches how to advantageously use snoop filtering in conjunction with point to point protocols by permitting several transmissions in-progress simultaneously, thereby increasing the data transfer parallelism and overall data throughput.
In accordance with the present invention, there is provided a snoop filtering method and apparatus for supporting cache coherency in a multiprocessor computing environment having multiple processing units, each processing unit having one or more local cache memories associated and operatively connected therewith. The method comprises providing a snoop filter device associated with each processing unit, each snoop filter device having a plurality of dedicated input ports for receiving snoop requests from dedicated memory writing sources in the multiprocessor computing environment. Each snoop filter device includes a plurality of parallel operating port snoop filters in correspondence with the plurality of dedicated input ports that are adapted to concurrently filter snoop requests received from respective dedicated memory writing sources and forward a subset of those requests to its associated processing unit.
According to the invention, there is provided a snoop filtering method and a snoop filter apparatus associated with a processing unit of a computing environment having multiple processing units for supporting cache coherency in the computing environment, the snoop filter apparatus comprising:
a plurality of inputs, each receiving a snoop request from a dedicated memory writing source in the computing environment; a snoop filter means provided for each input and adapted to concurrently filter received respective snoop requests from respective dedicated memory writing sources, each snoop filter means implementing one or more parallel operating sub-filter elements adapted for processing received snoop requests and forwarding a subset thereof to the associated processing unit, whereby as a result of the concurrent filtering, a number of snoop requests forwarded to a processing unit is significantly reduced thereby increasing performance of the computing environment.
In accordance with the present invention, one of said one or more parallel operating sub-filter elements comprises an address range filter means for determining whether an address of a received snoop request is within an address range comprising a minimum range address and a maximum range address.
Furthermore, one of said one or more parallel operating sub-filter elements comprises a snoop cache device adapted for tracking snoop requests received at the snoop filter means and recording addresses corresponding to snoop requests received; and, a snoop cache logic means in one to one correspondence with a respective snoop cache for comparing a received snoop request address against all addresses recorded in the corresponding snoop cache device, and, one of forwarding said received snoop request to the associated processing unit when an address does not match in the respective snoop cache device, or discarding the snoop request when an address match is found in the snoop cache device.
Furthermore, the processing unit has one or more cache memories associated therewith, and the snoop filter means comprises a memory storage means adapted to track cache line addresses of data that have been loaded into a cache memory level of its associated processor and record the cache line addresses. Accordingly, one of the one or more parallel operating sub-filter elements comprises a stream register check means for comparing an address of the received snoop request against corresponding addresses stored in the memory storage means; and, one of forwarding said received snoop request to said processor in response to matching an address in the memory storage means, or otherwise discarding the snoop request.
In one embodiment, the memory storage means comprises a plurality of stream register sets, each stream register set comprising a base register and a corresponding mask register pair, the base register tracking address bits common to all of the cache lines represented by the stream register; and, the corresponding mask register tracking bits representing differences to prior recorded addresses included in its corresponding base register.
Furthermore, each of the one or more parallel operating sub-filter elements generates a signal indicating whether a snoop request is to be forwarded to said associated processor or not forwarded. The snoop filter means further comprising: a means responsive to each signal generated from the sub-filter element for deciding whether a snoop request is to be forwarded or discarded.
Advantageously, the present invention enables snoop filtering to be performed on several requests simultaneously, while in the prior art systems, simultaneous snoop requests from several processors have to be serialized by the system bus. Allowing the processing of several snoop requests concurrently provides a significant increase in the number of requests which can be handled at any one time, and thus increase overall system performance.
BRIEF DESCRIPTION OF THE DRAWINGS
The objects, features and advantages of the present invention will become apparent to one skilled in the art, in view of the following detailed description taken in combination with the attached drawings, in which:
FIG. 1 depicts a base multiprocessor architecture with the coherence directory for cache coherency according to the prior art;
FIG. 2 depicts a base multiprocessor system using snooping approach for cache coherency according to the prior art;
FIG. 3 depicts a base multiprocessor system using snooping approach for cache coherency using a point-to-point connection described according to the present invention;
FIG. 4 illustrates an alternative embodiment base multiprocessor system using snooping approach for cache coherency using point-to-point connection where snoop filter is placed between the L2 cache and the main memory;
FIG. 5 depicts a high level schematic of a snoop filter block in accordance with a preferred embodiment of the invention;
FIG. 6 is a high level schematic of the snoop block containing multiple snoop filters according to the present invention;
FIG. 7 illustrates a high level schematic of a single snoop port filter according to the present invention;
FIGS. 8( a ) and 8 ( b ) depict high level schematics of two alternative embodiments of the snoop block according to the present invention;
FIG. 9 is a is a high level schematic of the snoop block including multiple port snoop filters according to a further embodiment of the present invention; FIG. 10 depicts the control flow for the snoop filter implementing snoop cache for a single snoop source according to the present invention; FIG. 11 depicts a control flow logic for adding a new entry to the port snoop cache inaccordance with the present invention; FIG. 12 depicts a control flow logic for removing an entry from the snoop cache in accordance with the present invention;
FIG. 13 depicts a block diagram of the snoop filter implementing stream registers in accordance with the present invention;
FIG. 14 depicts another embodiment of the snoop filter implementing stream registers filtering approach in accordance with the present invention;
FIG. 15 is a block diagram depicting the control flow for the snoop filter using paired stream registers and masks sets according to the invention; and,
FIG. 16 is a block diagram depicting the control flow for updating two stream register sets and the cache wrap detection logic for the replaced cache lines according to the invention;
FIG. 17 illustrates block diagram of signature filters to provide additional filtering capability to stream registers;
FIG. 18 is the block diagram of filtering mechanism using signature files in accordance with the present invention;
FIGS. 19( a ) and 19 ( b ) depict exemplary cache wrap detection logic circuitry (registers and comparator) for an N-way set-associative cache;
FIG. 20 depicts an exemplary cache wrap detection logic circuitry for an N-way set-associative cache according to a second embodiment of the invention that is based on a loadable counter; and,
FIG. 21 depicts an exemplary cache wrap detection logic circuitry for an N-way set-associative cache according to a third embodiment of the invention that is based on a scoreboard register.
DETAILED DESCRIPTION
Referring now to drawings, and more particularly to FIG. 3 , there is shown the overall base architecture of the multiprocessor system with the use of snooping approach for cache coherency. In the preferred embodiment, the multiprocessor system is composed of N processors 100 a, . . . , 100 n (or CPUs labeled DCU 1 to DCU N ) with their local L1 data and instruction caches, and their associated L2 caches 120 a, . . . , 120 n. The main memory 130 is shared and can be implemented on-chip or off-chip. In the alternative embodiment, instead of main memory, a shared L3 with access to main memory can be used. In the preferred embodiment, the processor cores 100 a, . . . , 100 n are PowerPC cores such as PPC440 or PPC405, but any other processor core can be used, or some combination of various processors in a single multiprocessor system can be used without departing from the scope of this invention. The processor cores 100 a, . . . , 100 n are interconnected by a system local bus 150 .
To reduce the number of snoop requests presented to a processor, and thus to reduce the impact of snooping on processor and system performance, and to reduce power consumed by unnecessary snoop requests, a snoop filter 140 a, . . . , 140 n is provided for each respective processor core 100 a, . . . , 100 n in the multiprocessor system 10 . For transferring snooping requests, the preferred embodiment does not use the system bus 150 , as typically found in prior art systems, but rather implements a point-to-point interconnection 160 whereby each processor's associated snoop filter is directly connected with each snoop filter associated with every other processor in the system. Thus, snoop requests are decoupled from all other memory requests transferred via the system local bus, reducing the congestion of the bus which is often a system bottleneck. All snoop requests to a single processor are forwarded to the snoop filter 140 a, . . . , 140 n, which comprises several sub-filters with the same filtering method, or with several different filtering methods, or any combination of the two, as will be described in greater detail herein. The snoop filter processes each snoop request, and presents only a fraction of all requests which are possibly in the processor's cache to the processor.
For each processor, snoop requests are connected directly to all other processors' snoop filters using a point-to-point interconnection 160 . Thus, several snoop requests (resulting from write and invalidate attempts) from different processors can occur simultaneously. These requests are no longer serialized, as in the typical snooping approach using the system bus, where this serialization is performed by the bus. That is, multiple snoop requests can be processed in the snoop filter concurrently, as will be described herein in further detail. As a processor has only one snoop port, the snoop requests not filtered out by a snoop filter will be serialized in a queue to be presented to the processor. However, the number of requests passed to the processor is much less than the pre-filtered number of all snoop requests, reducing the impact of cache coherence implementation on system performance.
To prevent queue overflowing condition of the queues contained in the snoop filter block, a token-based flow control system is implemented for each point to point link to limit the number of simultaneously outstanding requests. According to the token-based flow control, each memory writer can send the next write request—which also initiates snoop requests to all other processor units and accompanied snoop filter blocks—only if it has tokens available for all ports of the snoop filter blocks it has a direct point-to-point connection. If there are no tokens available from at least one of the remote ports it is connected to, no snoop requests can be sent out from this memory writer until at least one token from the said snoop filter port gets available again.
FIG. 4 illustrates an alternative embodiment of this invention, with a base multiprocessor system using a snooping approach for cache coherency with point-to-point interconnection for snooping requests, wherein the snoop filter is placed between the L2 cache and the main memory 230 . The multiprocessor system according to this embodiment thus comprises N processors 200 a, . . . , 200 n (or CPUs labeled DCU 1 to DCU N ) with their local L1 data and instruction caches, and their associated L2 caches 220 a, . . . , 220 n. The main memory 230 is shared and can be implemented on-chip or off-chip. In the alternative embodiment, instead of main memory, a shared L3 cache with access to main memory can be used. All memory access requests from processors 200 a, . . . , 200 n are transferred via a system local bus 250 . In the embodiment depicted in FIG. 4 , each of the processors in the multiprocessor system is paired with a respective snoop filter 240 a, . . . , 240 n. The point-to-point interconnection 260 is used to transfer snoop requests in the preferred embodiment in order to reduce the congestion of the system bus. In this point-to-point connection scheme 260 , each processor's associated snoop filter is directly connected with each snoop filter associated with every other processor in the system. All snoop requests to a single processor are forwarded to its snoop filter, which processes each snoop request, and forwards only an appropriate fraction of all requests to the processor. In this embodiment, the snoop requests are filtered at the L2 cache level (not at L1, as in the previous embodiment illustrated in FIG. 3 ), but the presented invention is applicable to any cache level, and can be used for other levels of the cache hierarchy without departing from the scope of the invention.
Referring now to FIG. 5 , there is depicted a high level block diagram of the snoop filter device according to the present invention. Snoop requests from all other processors 1 to N in a multiprocessor system are forwarded to the snoop block 310 via dedicated point-to-point interconnection inputs 300 a, . . . , 300 n. The snoop block 310 filters the incoming snoops and forwards the appropriate subset to the processor 320 via the processor snoop interface 340 . In addition, the snoop block 310 monitors all memory access requests from the processor and L1 data cache block 320 to the L2 cache 330 . These are only requests which miss in the L1 cache. The snoop block monitors all read address and control signals 360 and 362 to update its filters accordingly.
FIG. 6 depicts a high level schematic of the snoop block 310 depicted in FIG. 5 . As shown in FIG. 6 , the snoop block 310 includes multiple (“N”) port snoop filters 400 a, . . . , 400 n that operate in parallel, with each dedicated only to one source of N memory writers (processors or a DMA engine sub-system, etc.). Each of the port snoop filters 400 a, . . . , 400 n receive on its dedicated input 410 a, . . . , 410 n snoop requests from a single source which is directly connected point-to-point. As will be described herein, a single port snoop filter may include a number of various snoop filter methods. The snoop block 310 additionally includes a stream register block 430 and snoop token control block 426 . In addition, each port snoop filter 400 a, . . . , 400 n monitors all memory read access requests 412 from its associated processor which miss in the processor's L1 level cache. This information is also provided to the stream register block 430 for use as will be described in greater detail herein.
In operation, the port snoop filters 400 a, . . . , 400 n process the incoming snoop requests and forward a subset of all snoop requests to a respective snoop queue 420 a, . . . , 420 n having one queue associated with each snoop port. A queue arbitration block 422 is provided that arbitrates between all the snoop queues 420 and serializes all snoop requests from the snoop queues 420 fairly. Logic is provided to detect a snoop queue overflow condition, and the status of each queue is an input to a snoop token control unit 426 that controls flow of snoop requests from the remote memory writers. A memory writer—being a processor or a DMA engine—can submit a write to the memory and a snoop request to all snoop filters only if it has a token available from all snoop filters. The only snoop filter from which a processor does not need a token available to submit a write is its own local snoop filter. This mechanism ensures that the snoop queues do not overflow. From the snoop queue selected by arbiter 422 , snoop requests are forwarded to the processor via a processor snoop interface 408 .
FIG. 7 illustrates a high level schematic of a single snoop port filter 400 . The snoop port filter block 400 includes multiple filter units which implement various filtering algorithms. In the preferred embodiment, three snoop filter blocks 440 , 444 , and 448 operate in parallel, each implementing a different snoop filter algorithm. The snoop filter blocks are labeled snoop cache 440 , stream register check unit 444 , and range filter 448 . In one embodiment, each of the parallel snoop filter blocks receives on its input an identical snoop request 410 from a single source simultaneously. In addition, the snoop cache 440 monitors all memory read access requests 412 from the processor which miss in the L1 level cache, and stream registers check unit 444 receives status input 432 from the stream register unit 430 depicted in FIG. 6 .
According to the preferred embodiment, the snoop cache block 440 filters the snoop requests 410 using an algorithm which is based on the temporal locality property of snoop requests, meaning that if a single snoop request for a particular location was made, it is probable that another request to the same location will be made soon. The snoop cache monitors every load made to the local cache, and updates its status, if needed. The stream register check block 444 filters snoop requests 410 using an algorithm that determines a superset of the current local cache content. The approximation of cache content is included in the stream registers block 430 ( FIG. 6 ), and the stream register status 432 is forwarded to each snoop port filter 400 . Based on this status, for each new snoop requests 410 , a decision is made if the snoop address can possibly be contained in the local cache. The third filtering unit in the snoop port filter is the range filter 448 . For this filtering approach, two range addresses are specified, the minimum range address and the maximum range address. The filtering of a snoop request is performed by first determining if the snoop request is within the address range determined by these two range addresses. If this condition is met, the snoop request is discarded; otherwise, the snoop request is forwarded to the decision logic block 450 . Conversely, the request can be forwarded when it falls within the address range and discarded otherwise, without departing from the scope of the invention. Particularly, the decision logic block 450 receives results 456 of all three filter units 440 , 444 and 448 together with the control signals 454 which enable or disable each individual snoop filter unit. Only results of snoop filter units for which the corresponding control signals are enabled are considered in each filtering decision. If any one of the filtering units 440 , 444 or 448 decides that a snoop request 410 should be discarded, the snoop request is discarded. The resulting output of this unit is either to add the snoop request to the corresponding snoop queue 452 , or to discard the snoop request and return a snoop token 458 to the remote processor or DMA unit that initiated the discarded snoop request.
In the preferred embodiment, only the three filtering units implementing the algorithms above described are included in a port snoop filter, but one skilled in the art will appreciate that any other number of snoop filter units can be included in a single port snoop filter, or that some other snoop filter algorithm may be implemented in the port snoop filter, or a combination of snoop algorithms can be implemented, without departing from the scope of the invention.
FIGS. 8( a ) and 8 ( b ) depict high level schematics of two alternative embodiments of the snoop filter block 310 of FIG. 6 . As described herein with respect to FIG. 6 , the snoop block may include multiple snoop filters that can use various filtering approaches, the same filtering approach, or a combination of the two. As shown in FIG. 8( a ), N port snoop filters 460 a, . . . , 460 n operate in parallel, one for each of N remote memory writers. Each of the port snoop filters 460 a, . . . , 460 n receive on its respective input 462 a, . . . , 462 n snoop requests from a single dedicated source which is connected point-to-point. In addition, each snoop filter 460 a, . . . , 460 n monitors all of the local processor's memory load requests 464 which have missed in the L1 level cache. Other signals from other units of the snoop block may also be needed to supply to the port snoop filters, if required by the filter algorithm implemented. The exact signals needed are determined by the one or more snoop filter algorithms implemented in a single port snoop filter 460 . Additionally, it should be understood that all port snoop filters do not have to implement the same set of filtering algorithms.
The port snoop filters 460 a, . . . , 460 n filter the incoming snoops and forward the appropriate unfiltered subset of snoop requests into the respective queues 466 a, . . . , 466 n and the queue arbitration block 468 . Here, the snoop requests are serialized and presented to a next snoop filter 470 , which handles inputs from all remote memory writers. This shared snoop filter 470 processes all snoop request presented and forwards a subset of all requests to the snoop queue 472 . From the snoop queue 472 , snoop requests are forwarded to the processor via the processor snoop interface 474 . It should be understood that it is possible to have multiple or no shared snoop filters 470 instead of the configuration shown in FIG. 8( a ). In the case of multiple shared filters, the filters may be arranged in parallel or in series (in which case the output of one filter is the input to the next, for example). If a filter has inputs from more than one source (i.e., is shared between multiple sources), it has to have its own input queue and an arbiter to serialize snoop requests. A final ordered subset of all snoop requests is placed in the snoop queue 472 , and snoop requests are forwarded to the processor via the processor snoop interface 474 . Optionally, a snoop queue full indication signal 476 is provided that indicates when the snoop queue is full in order to stop some or all remote memory writers from issuing further snoop requests until the number of snoops in the snoop queue falls below a predetermined level.
Similarly, FIG. 8( b ) illustrates another embodiment with an alternative organization of the snoop filters in the snoop block 310 . N port snoop filters 480 a, . . . , 480 n, each receiving only snoop requests from one of N remote memory writers (i.e., excluding the processor where the snoop filter is attached), operate in parallel. Each port snoop filter 480 a, . . . , 480 n receives on its respective input snoop requests 482 a, . . . , 482 n from only a single source, respectively. A shared snoop filter 484 is connected in parallel with the port snoop filter devices 480 a, . . . , 480 n. In an alternative embodiment, more than one shared snoop filter can be attached in parallel. The shared snoop filter 484 handles inputs from all N remote memory writers. Having more than one input, the shared filter 484 has its own input queues 486 and a queue arbiter 488 for serializing snoop requests. Further in the embodiment depicted in FIG. 8( b ), all port snoop filters 480 a, . . . , 480 n and the shared snoop filter 484 monitor all memory read access requests 490 from the local processor which miss in the L1 level cache. The snoop filters 480 a, . . . , 480 n and 484 filter the incoming snoop requests and forward the appropriate unfiltered subset to the input queue of the next shared snoop filter 492 a, . . . , 492 n. Here, the unfiltered snoop requests are serialized by the queue arbiter 494 , and are forwarded to the processor via the processor snoop interface 496 . If one of the snoop queue devices 492 a, . . . , 492 n or 486 is full, a snoop queue full indication 498 is activated to stop all (or some of) the remote memory writers from issuing further snoop requests until the number of snoops in the snoop queue falls below a the predetermined level.
Referring now to FIG. 9 , there is depicted a further embodiment of the snoop filter block 310 . The block contains N port snoop filters 500 a, . . . , 500 n, corresponding to port snoop filters 400 , 460 a, . . . , 460 n, and 480 a, . . . , 480 n (of FIGS. 8( a ) and 8 ( b )). Each port snoop filter 500 a, . . . , 500 n includes a snoop cache device 502 a, . . . , 502 n, and a snoop check logic 504 a, . . . , 504 n. The snoop cache devices 502 a, . . . , 502 n implement a snoop filtering algorithm which keeps track of recent snoop requests from one source, where the source of snoop requests can be another processor, a DMA engine, or some other unit. For each new snoop request from a single source, the snoop request's address is checked against the snoop cache in the snoop check logic block 504 . If the result of this comparison matches, i.e., the snoop request is found in the snoop cache, the snooped data is guaranteed not to be in the local L1 level cache of the processor. Thus, no snoop request is forwarded to the snoop queue 506 and the snoop queue arbiter 508 . If no match is found in the snoop cache 502 a, . . . , 502 n for the current snoop request, the address of the snoop requests is added to the snoop cache using the signals 514 a, . . . , 514 n. Concurrently, the snoop request is forwarded to the snoop queue 506 .
All snoop cache devices 502 a, . . . , 502 n also receive read addresses and requests 512 from the local processor, and compare the memory read access addresses to the entries in the snoop cache 502 a, . . . , 502 n. If a request matches one of the entries in the snoop cache, this entry is removed from the snoop cache, as now the cache line is going to be located in the processor's first level cache. In the preferred embodiment, multiple snoop caches operating in parallel are used, each keeping track of snoop requests from a single remote memory writer. After filtering, a fraction of unfiltered snoop requests can be forwarded to the next port snoop filter, or they can be queued for one or more shared snoop filters, or they are placed in the snoop queue of the processor interface, depending on the embodiment.
It is understood that a single snoop cache device 502 includes an internal organization of M cache lines (entries), each entry having two fields: an address tag field, and a valid line vector. The address tag field of the snoop cache is typically not the same as the address tag of the L1 cache for the local processor, but it is shorter by the number of bits represented in the valid line vector. Particularly, the valid line vector encodes a group of several consecutive cache lines, all sharing the same upper bits represented by the corresponding address tag field. Thus, the n least significant bits from an address are used for encoding 2 n consecutiveL1 cache lines. In the extreme case when n is zero, the whole entry in the snoop cache represents only one L1 cache line. In this case, the valid line vector has only one bit corresponding to a “valid” bit.
The size of the address tag field in the snoop cache is determined by the size of the L1 cache line and the number of bits used for encoding the valid line vector. In an example embodiment, for an address length of 32 bits ( 31 : 0 ), an L1 cache line being 32 bytes long, and a valid line vector of 32 bits, address bits ( 31 : 10 ) are used as the address tag field, (bit 31 being the most significant), address bits ( 9 : 5 ) are encoded in the valid line vector, and address bits ( 4 : 0 ) are ignored because they encode the cache line byte offset. As an illustration, three snoop caches for three different memory writers (N=3) are listed below, each snoop cache having M=4 entries, with address tag field to the left, and with 5 bits from the address used to encode the valid line vector to track 32 consecutive cache lines:
Snoop requests source 1 Entry 1: 01c019e 00000000000000000001000000000000 Entry 2: 01c01a0 00000000000000000000000100000000 Entry 3: 01c01a2 00000000000000000000000000010000 Entry 4: 01407ff 00000000000000000000000110000000
Snoop requests source 2
Entry 1: 01c01e3 00010000000000000000000000000000 Entry 2: 01c01e5 00000001000000000000000000000000 Entry 3: 01c01e7 00000000000100000000000000000000 Entry 4: 0140bff 00000000000000000000000110000000
Snoop requests source 3
Entry 1: 01c0227 00000000000000000001000000000000 Entry 2: 01c0229 00000000000000000000000100000000 Entry 3: 01c022b 00000000000000000000000000010000 Entry 4: 0140fff 00000000000000000000000110000000
In this example, entry 1 of the source 1 snoop cache has recorded that address 01c019ec hexadecimal has been invalidated recently and cannot possibly be in the L1 cache. Therefore, the next snoop request to the same cache line will be filtered out (discarded). Similarly, entry 4 of the source 1 snoop cache will cause snoop requests for cache line addresses 01407ff7 and 01407ff8 to be filtered out.
Referring now to FIG. 10 , the control flow for the snoop filter implementing a snoop cache device for a single snoop source is shown. At the start of operation, all M lines in the snoop cache are reset as indicated at step 600 . When a new snoop request from a snoop source i is received, the address of the snoop request is parsed into the “address tag” field 526 and into bits used for accessing the valid line vector 524 . The valid line vector of the snoop request has only one bit corresponding to each L1 cache with address bits matching the address tag field. This is performed in the step 602 . In the step 604 , the “tag” field of the snoop request is checked against all tag fields in the snoop cache associated with the snoop source i. If the snoop request address tag is the same as one of the address tags stored in the snoop cache, the address tag field has hit in the snoop cache. After this, the valid line vector of the snoop cache entry for which a hit was detected is compared to the valid line vector of the snoop request. If the bit of the valid line vector in the snoop cache line corresponding to the bit set in the valid line vector of the snoop request is set, the valid line vector has hit as well. In one preferred embodiment, the valid line vector check is implemented by performing a logical operation upon the bit operands. Thus, for example, the valid line vector check may be performed by AND-ing the valid line vector of the snoop request with the valid line vector of the snoop cache line, and checking if the result is zero. It is understood that other implementations may additionally be used without departing from the scope of this invention. It is further understood that checking for a valid line vector hit can be implemented in parallel with checking for an address tag hit.
At step 606 , a determination is made as to whether both the “tag” field matches and the corresponding bit in the valid line vector is set. If both the “tag” field matches and the corresponding bit in the valid line vector is set, the snoop request is guaranteed not to be in the cache as indicated at step 606 . Thus, this snoop request is not forwarded to the cache; it is filtered out as indicated at step 608 .
Otherwise, if the address “tag” field hits in the snoop cache but the bit in the valid line vector is not set or, alternately, if the tag does not hit in the snoop cache, this indicates that the line may be in the cache. Consequently, the snoop request is forwarded to the cache by placing it into a snoop queue as indicated at step 612 . This snoop request is also added as a new entry to the snoop cache as shown at step 610 .
Referring now to FIG. 11 , there is shown the details of step 610 ( FIG. 10 ) describing the process of adding new information in the snoop cache. This is accomplished by several tasks, as will now be described. At step 614 , a determination is first made as to whether the address tag is already stored in the snoop cache (i.e., the address tag was a hit). For this step, the information calculated in step 602 ( FIG. 10 ) can be used. If the address tag check gave a hit, then the process proceeds to step 624 , where the bit in the valid line vector of the selected snoop cache entry corresponding to the snoop request is set. If the address tag check gave a miss in step 614 , a new snoop cache entry has to be assigned for the new address tag, and the process proceeds to 616 where a determination is made as to whether there are empty entries available in the snoop cache. If it is determined that empty entries are available, then the first available empty entry is selected as indicated at step 620 . Otherwise, if it is determined that there are no empty entries in the snoop cache, one of the active entries in the snoop cache is selected for the replacement as indicated at step 618 . The replacement policy can be round-robin, least-recently used, random, or any other replacement policy known to skilled artisans without departing from the scope of this invention. Continuing to step 622 , the new address tag is then written in the selected snoop cache line and the corresponding valid line vector is cleared. Then, as indicated at step 624 , the bit in the valid line vector of the selected snoop cache entry corresponding to the bit set in the valid line vector of the snoop request is set.
In yet another embodiment, the new information is not added into the snoop cache based on the hit or miss of a snoop request in the snoop cache only, but instead, the addition of new values—being whole snoop cache lines or only setting a single bit in a valid line vector—is based on the decision of the decision logic block 450 ( FIG. 7 ). In this embodiment, the new information is added into the snoop cache only if the decision logic block does not filter out the snoop request. If any other filter in the snoop port filter block 400 ( FIG. 7 ) filters out the snoop request (i.e., determines that the data are not in the local L1 cache), no new information is added to the snoop cache, but the operation steps are the same as for snoop cache hit case. The advantage of this embodiment is that the snoop cache performs better because less redundant information is stored.
Referring now to FIG. 12 , there is depicted the control flow for removing an entry from a snoop cache. On each local processor memory read request which misses in the local L1 level cache, the address of the memory request is checked against all entries in all snoop caches associated with all snoop request sources. In step 630 , the address of the memory read request is parsed into an address tag field and into bits used for encoding the valid line vector. This is performed in the step 630 . In the step 632 , a determination is made as to whether there are one or more tag hits. This is accomplished by checking the “tag” field of the memory request against all tag fields in all snoop caches associated with all snoop sources. If the tag check misses, this address is not being filtered out and nothing has to be done. Thus, the control flow loops back to step 630 to wait for the next cache miss from the processor.
Returning to step 632 , if it is determined that the comparison of the address tag with all snoop caches results in one or more hits, the information has to be removed from all snoop caches for which it was hit. Thus, at step 634 , the appropriate low order bits of the memory read address are decoded into a valid line vector, and is matched against the valid line vector of the snoop cache entry that was hit as indicated in step 635 . Proceeding now to step 636 , it is determined whether the unique bit set in the read address vector is also set in the valid line vector of the snoop cache. If there is no such valid line vector hit (regardless of the address tag field hit), this memory address is not filtered out and nothing has to be changed in the particular snoop cache. Thus, the control flow proceeds to step 640 to check if all address tag hits have been processed, and if not, the process returns to step 635 .
If, however, it is determined at step 636 that the read address vector hits in the valid line vector, then the read address is being filtered out. The corresponding valid line vector bit has to be cleared since the memory read address is going to be loaded into the first level cache. This clearing of the corresponding bit in the valid line vector is performed at step 638 . If after removing the corresponding bit from the valid line vector the number of bits set of the valid line vector becomes zero, the address tag field is further removed from the snoop cache causing the entry to be empty. As next indicated at step 640 , the same process of checking for the valid line vector bit, its clearing, and clearing of the address tag—if necessary—is repeated for all snoop caches which hit the memory read request which was miss in the local L1 cache. This condition that all hit address tag lines have been processed is checked at step 640 . Once all of the cache lines have been checked, the process returns to step 630 .
In yet another embodiment, the local memory request is compared to all address tags in all snoop caches simultaneously. Concurrently, the valid line vector encoding of the local memory request may be compared with all valid line vectors in all snoop caches in which there were hits simultaneously. Then, these two results—address tag hit and valid line vector hit—can be combined to determine all snoop cache lines from which the corresponding valid line vector bit has to be removed, and all these bits can be removed from the hitting cache lines from all snoop caches simultaneously.
Referring now to FIG. 13 , there is depicted the block diagram of the snoop filter device implementing stream registers. In one preferred embodiment, the snoop filter unit comprises the following elements: two sets of stream registers and masks 700 , a snoop check logic block 702 , a cache wrap detection logic block 706 , a stream register selection logic block 704 , filter queues 703 , and a processor arbitrate and multiplex logic 710 . As will be described in greater detail herein, unlike the snoop cache filters that keep track of what is not in the cache, the stream registers and masks sets 700 keep track of recent data which were loaded into the cache of the processor. More precisely, the stream registers keep track of at least the lines that are in the cache, but may assume that some lines are cached which are not actually in the cache. However, forwarding some unnecessary snoop requests to the cache does not affect correctness.
The heart of the stream register filter is the stream registers 700 themselves. One of these registers is updated every time the cache loads a new line, which is presented to the stream registers with appropriate control signals 716 . Logic block 704 in FIG. 13 is responsible for choosing a particular register to update based upon the current stream register state and the address of the new line being loaded into the cache in signals 716 .
In operation, snoop requests received from one of the N remote processors arrive as signals 714 shown in the right-hand side of FIG. 14 . The snoop check logic 702 comprises a set of port filters that compare the addresses of the arriving snoop requests 714 with the state of the stream registers 700 to determine if the snoop requests could possibly be in the cache. If so, the requests are forwarded to queues 703 where they wait to be forwarded to the cache as actual cache snoops. The queuing structure of FIG. 13 , where each of the N remote processors has a dedicated snoop request queue 703 , is designed to allow for the maximum snoop request rate since a large number of the snoop requests will be filtered out and will never need to be enqueued. Alternative queuing structures are possible without departing from the general scope of the invention.
The arbitrate and multiplex logic block 710 simply shares the snoop interface of the cache between the N snoop request queues 703 in a fair manner, guaranteeing forward progress for all requests.
A description of how a single stream register is updated is now provided. A stream register actually comprises a pair of registers, the “base” and the “mask”, and a valid bit. The base register keeps track of address bits that are common to all of the cache lines represented by the stream register, while the corresponding mask register keeps track of which bits these are. The valid bit simply indicates that the stream register is in use and should be consulted by the snoop check logic 702 when deciding whether to filter a remote snoop request 714 . In order to understand the examples in the following description, consider an address space of 2 32 bytes with a cache line size of 32 bytes. In this case, a cache line load address is 27 bits in length, and the base and mask registers of the stream registers are also 27 bits in length.
Initially, the valid bit is set to zero, indicating that the stream register is not in use, and the contents of the base and mask register is irrelevant. When the first cache line load address is added to this stream register, the valid bit is set to one, the base register is set to the line address, and all the bits of the mask register are set to one, indicating that all of the bits in the base register are significant. That is, an address that matches the address stored in the base register exactly is considered to be in the cache, while an address differing in any bit or bits is not. For example, given a first cache line load address is 0x1708fb1 (the 0x prefix indicates hexadecimal). Then the contents of the stream register after the load is:
Base=0x1708fb1 Mask=0x7ffffff Valid=1
Subsequently, when a second cache line load address is added to this stream register, the second address is compared to the base register to determine which bits are different. The mask register is then updated so that the differing bit positions become zeros in the mask. These zeros thus indicate that the corresponding bits of the base register are “don't care”, or can be assumed to take any value (zero or one). Therefore, these bits are no longer significant for comparisons to the stream register. For example, say the second cache line load address is 0x1708fb2. Then the contents of the stream register after this second load is:
Base=0x1708fb1 Mask=0x7fffffc Valid=1
In other words, the second address and the base register differed in the two least significant bits, causing those bits to be cleared in the mask register. At this point, the stream register indicates that the addresses 0x1708fb0, 0x1708fb1, 0x1708fb2, and 0x1708fb3 can all be in the cache because it can no longer distinguish the two least significant bits. However, it is important to note that the two addresses which have actually been loaded are considered to be in the cache. This mechanism thus guarantees that all addresses presented to the stream register will be included within it. In the limit, the mask register becomes all zeros and every possible address is included in the register and considered to be in the cache. Clearly, the mechanism described can be used to continue adding addresses to the stream register.
Every cache line load address is added to exactly one of the multiple stream registers. Therefore, the collection of stream registers represents the complete cache state. The decision of which register to update is made by the update choice logic block 704 in FIG. 13 . One possible selection criteria is to choose the stream register with minimal Hamming distance from the line load address (i.e. the stream register which will result in the minimum number of mask register bits changing to zero). Yet another selection criteria is to choose the stream register where the most upper bits of the base register match those of the line load address. Other selection criteria are possible and can be implemented without departing from the scope of the invention.
In selecting a stream address register to update, the line load address is compared to all base registers combined with their corresponding mask registers in parallel. The line load address is then added to the selected stream register as described herein.
The snoop check logic block 702 determines whether a snoop address 714 could possibly be in the cache by comparing it to all of the stream registers as follows: the snoop address 714 is converted to a line address by removing the low-order bits corresponding to the offset within a cache line. This line address is compared with a single stream register by performing a bitwise logical exclusive-OR between the base register and the snoop line address, followed by a bitwise logical AND of that result and the mask register. If the final result of these two logical operations has any bits that are not zero, then the snoop address is a “miss” in the stream register and is known not to be in the cache, as far as that stream register is concerned. The same comparison is performed on all of the stream registers in parallel, and if the snoop line address misses in all of the stream registers, then the snoop address is known not to be in the cache and can be filtered out (i.e. not forwarded to the cache). Conversely, if the snoop address hits in any one of the stream registers, then it must be forwarded to the cache.
The snoop check logic 702 is duplicated for each of the N remote snoop request ports, but they all share the same set of stream registers 700 .
Over time, as cache line load addresses are added to the stream registers, they become less and less accurate in terms of their knowledge of what is actually in the cache. As illustrated in the example above, every mask bit that becomes zero increases the number of cache lines that the corresponding stream registers specifies as being in the cache by a factor of two. In general, the problem of forwarding useless snoop requests to the processor (i.e., failing to filter them) becomes worse as the number of mask bits that are zero increases. Therefore, the stream register snoop filter are provided with a mechanism for recycling the registers back to the initial condition. This mechanism is based upon the observation that, in general, lines loaded into the cache replace lines that are already there. Whenever a line is replaced, it can be removed from the stream registers, since they only track which lines are in the cache. Rather than remove individual lines, the stream register snoop filter effectively batches the removals and clears the registers whenever the cache has been completely replaced. However, the new cache lines that were doing this replacement were also added into the stream registers, so the contents of those registers cannot simply be discarded.
To solve this dilemma, the stream register snoop filter performs the following: starting with an initial cache state, stream register updates occur as described previously herein. The cache wrap detection logic block 706 is provided with functionality for monitoring cache update represented by cache update signals 717 and determining when all of the cache lines present in the initial state have been overwritten with new lines, i.e. the cache has “wrapped”. At that point, contents of all of the stream registers (call them the “active” set) are copied to a second “history” set of stream registers and the stream registers in the active set are all returned to the invalid state to begin accumulating cache line load addresses anew. In addition, the state of the cache at the time of the wrap becomes the new initial state for the purpose of detecting the next cache wrap. The stream registers in the history set are never updated. However, they are treated the same as the active set by the snoop check logic 702 when deciding whether a snoop address could be in the cache. With this mechanism, the stream registers are periodically recycled as the cache is overwritten.
There are a number of ways that cache wrapping can be detected depending upon the cache update policy and the cache update signals 717 . For example, if the cache specifies the line that is overwritten, then a simple scoreboard can be used to determine the first time that any particular line is overwritten and a counter can be used to determine when every line has been overwritten at least once. Any mechanism for detecting cache wrapping can be used without departing from the scope of the invention.
FIG. 14 shows an alternative embodiment of the stream register snoop filter, where the filter is entirely shared by the N remote processors. That is, the individual snoop request ports 714 do not have their own snoop check logic 702 as shown in the embodiment described with respect to FIG. 13 . In this embodiment, snoop requests are enqueued in queue structures 708 before being input to a shared snoop check logic block 701 . The queued requests are forwarded in a fair manner to the snoop check logic block 701 via an arbitrate and multiplex logic 705 . The functionality of the snoop check logic block 701 is otherwise identical to the previous stream register snoop filter check logic as described herein with respect to FIG. 13 . Clearly, alternative queuing structures 708 are possible and do not depart from the general scope of the invention.
In a preferred embodiment, two sets of stream registers are used, but more than two sets can be used without departing from the scope of the invention. For example, in an embodiment implementing four sets of stream registers, two sets of active registers, A and B, and two sets of corresponding history registers, are implemented. In this embodiment, the A set of stream registers can contain information related to one subset of the cache, and the B set of stream registers can contain information related to a different subset of the cache. The partition of the cache into parts assigned to each set of stream registers, A and B, can be performed by dividing the cache into two equal parts, but other partitions may be used. Furthermore, the number of stream register sets can be more than two. For example, there can be one set of stream registers assigned to each cache set of a set-associative cache.
In yet another embodiment, there can be more than one history set of stream registers, allowing the active set to be recycled more frequently. However, care must be taken to manage the history registers relative to cache wrap detections so that a register is never cleared when a cache line covered by that register could still be in the cache. One way to ensure that a register is never cleared is to add history registers to the active set of stream registers and then copy all of those history registers (and the active registers) to a second set of history registers when the cache wraps. This is essentially adding a second “dimension” of history to the preferred embodiment of the stream register snoop filter as described herein.
Referring now to FIG. 15 , there is depicted a detailed process flow diagram of the control flow for the snoop filter using paired base register and mask register sets. At the start of operation, all stream registers and masks and snoop queues are reset as indicated at step 730 , and the system waits for the next snoop request from any snoop source as indicated at step 732 . When a new snoop request is received, the address of the snoop request is checked against all address stream register and masks (both sets of the stream registers) as depicted in step 734 . The address of the snoop requests is checked against all stream registers combined with accompanied masks (i.e., all address stream register and masks (both sets of the stream registers)). If the comparison of the current snoop request matches a stream register combined with the paired mask register as determined at step 736 , the snooped cache line might be in the cache and the snoop request is forwarded to the cache by placing the snoop request into snoop queue in step 740 . The process returns to step 732 to wait for the next snoop request. If, however, the snoop request does not match any stream register combined with the paired mask register in the both sets of stream registers, the snooped cache line is guaranteed not in the cache. Thus, this snoop request is filtered out in the step 738 and the process returns to step 732 .
Referring now to FIG. 16 , there is depicted the control flow for updating two stream register sets and the cache wrap detection logic block for the replaced cache lines. At the start of operation, all stream registers and masks are reset and the cache wrap detection logic is cleared as indicated at step 750 , and first set of registers is activated. For each processor memory request (including either a load or store operation) that misses in L1 cache, the address of the memory request is added to a first set of stream registers, referred to as an active address stream register set. All address stream registers from the first set of registers are checked to select the best match—as specified by the implemented register selection criteria; alternately, the first empty stream register may be selected. The address of the memory request is stored into the selected stream address register in the active register set as indicated at step 752 , and the paired mask is updated to reflect which bits of the address are relevant, and which are not. Then, at step 754 , the cache wrap detection logic is updated to reflect the new data loaded in the cache. The cache wrap detection block keeps track of whether all lines in the cache have been replaced since first use of the active registers was initiated. Thus, at step 756 , a determination is made as to whether a cache wrap condition exists. If a cache wrap condition is not detected in step 756 , the control flow loops back to the step 752 where the system waits for the next processor memory request. Otherwise, if a cache wrap condition is detected, the control continues to the step 758 where the cache wrap detection logic block is cleared and a second stream registers and masks set are cleared in the step 758 . Proceeding next to step 760 , the system waits for the next processor memory request. For the new memory request, all address stream registers from the second set of registers are checked to select the best match, e.g., as specified by the implemented register selection criteria, for example, or, the first empty stream register is selected. The address of the memory request is stored into the selected stream address register in the second register set as indicated at step 760 , and the paired mask is updated to reflect which bits of the address are relevant. Proceeding to step 762 , the cache wrap detection logic is updated to reflect the new data loaded in the cache. As the cache wrap detection logic keeps track of all lines in the cache that have been replaced since first use of the second set of registers was initiated, a determination is then made at step 764 to determine if a cache wrap condition exists. If no cache wrap event is detected in the step 764 , the system waits for the next processor memory request by returning to step 760 . If, however, the cache wrap event is detected, the first set of registers and masks will be used again. Thus, all registers and paired masks from the first set of registers are reset, the cache wrap detection logic is cleared in the step 766 . The first set of registers are going to be used again as active for approximating the content of the cache, and the control flow is looped back to the step 752 .
As described herein with respect to use of the stream register snoop filter, the power of each stream register filter to block snoop requests decreases as the number of mask bits set to zero increases. For example, if all mask bits are zero, then all snoop requests must be sent through. However, supposing these mask bits were set to zero one bit at a time (i.e., each load differs from the stream register by only one bit), then, in such a case, a snoop request for an address having exactly two bits different from the stream register would be let through, even though this address cannot be in the cache. Accordingly, additional filtering capability is provided by implementing signature filters that enable detection of more complicated, or subtle, differences such as the number of different bits. The general idea is that a snoop is forwarded from a stream register only if both the mask filter and the signature filter indicate that the address might be in the cache.
Referring to FIG. 17 , there is a signature function 900 that takes as inputs, an address 901 and a stream register 902 and computes the signature 903 of the address, relative to the stream register. There are many possible signature functions, such as:
1. The number of bits in the address that are different than the stream register address. Denote this number by s. Truncation can be used to save space, e.g., set the signature to min(M,) for some constant M. 2. If the address is N bits long, the signature is a vector of length B=(N+1) bits with zeros in every bit except for a one in bit i if s=i. To save space, this could be truncated to a vector of length B+1 (B+1<N) where there is a one in bit i if min(s,B)=i. 3. Divide the address into k (k>1) groups of bits. The length of group i is L(i) bits and let M(i)=L(i)+1. Let s(i) be the number of address bits in group i that are different than the stream register bits in group i. Then the signature is given by (s(1), s(2) . . . , s(k)), which is simply the number of different bits in each group. These groups may consist of either disjoint sets of bits, or partially overlapping sets of bits (i.e., some bit of an address is in more than one group). The length of the signature is B(1)+ . . . +B(k) bits where B(i) is the number of bits required to represent all possible values of s(i). 4. A combination of (2) and (3) above, in which the signature consists of k bit vectors corresponding to each of the groups. Bit i in group j is set to one if s(j)=i. If group i is of length L(i) bits then it requires M(i)=(L(i)+1) bits to encode all possible values of s(i). The signature is M(1)+ . . . +M(k) bits long. Truncation can be used to save space, e.g., bit i in group j is set to one if min(M,s(j))=i for some constant M. 5. As in (3) above, but there are M(1)* . . . *M(k) different unique combinations of s(1), . . . , s(k). Assign an integer q to each combination, and set the signature to a vector of all zeros except for a one in bit q. Truncation, as in (4) above, can reduce space. 6. Divide the address into k (k>1) groups of bits and let p(i) be the parity of the address bits in group i. Then the signature is given by (p(1), p(2) . . . , p(k)). 7. As in (6) above, but encode each of the 2 k combinations of parity to an integer q, and return a bit vector of length 2 k zeros, except for a one in bit q. It is understood that many other signatures are possible.
If the address 901 is a load to the cache, the signature 903 is fed to a signature register updater 904 . The updater also takes the previous value of a signature register 905 as input and replaces it by a new value 906 . The appropriate way to update the signature register depends on the type of signature. Let S_old denote the old value of the signature register, S_new denote the new value of the signature register, and V denote the value of the signature 903 . Corresponding to the signature functions above, the signature updater 904 computes:
1. S_new=max(S_old,V). This keeps track of the maximum number of bits that differ from the stream register. 2. S_new=S_old bit-wise-or V. This keeps a scoreboard of the number of different bits. 3. S_new=max(S_old,V). This keeps track of the maximum number of bits in each group that differ from the stream register. 4. S_new=S_old bit-wise-or V. This keeps a scoreboard of the number of different bits in each group. 5. S_new=S_old bit-wise-or V. This keeps a scoreboard of the number of different bits in each group that occur simultaneously. 6. S_new=S_old bit-wise-or V. This keeps a scoreboard of the parity in each group. 7. S_new=S_old bit-wise-or V. This keeps a scoreboard of the parity in each group that occur simultaneously.
When a snoop request comes in, its signature is computed and compared to the signature register. It a match does not occur there, the address cannot be in the cache, so the request is filtered even if the normal stream register and mask filter indicates that it might be in the cache. A snoop is forwarded only if the signature register and mask register both indicate that the address might be in the cache.
The signature filtering mechanism is shown in FIG. 18 . A load address 1001 to the cache is sent to the mask update logic 1002 which operates as described earlier, taking the previous mask register 1003 , a stream register 1004 and updating the mask register 1003 . This address 1001 is also fed to a signature function 1005 that also takes the stream register 1004 as input and produces a signature 1006 . The signature 1006 and previous signature register 1008 are fed to the signature update logic 1007 that creates a new value for the signature register 1008 .
When a snoop address 1009 a request comes in, it is received and processed by the mask filter 1010 producing a mask snoop request 1011 . In addition, this same snoop address (shown as 1009 b ) and the stream register 1004 are fed to the signature function 1012 producing a signature 1013 . Note that the signature functions 1005 and 1012 must be identical logic, meaning that if they have the same inputs they will produce the same outputs. The signature of the snoop request 1013 and the signature register are fed to the signature filter 1014 .
This filter must determine if a request having this signature might be in the cache and its exact operation depends on the type of signature. In the case of the “scoreboard” types of signature updaters, the snoop signature is bit-wise and-ed with the signature register. If the result of this is non-zero, then a signature snoop request 1015 is made (i.e., that signal is set to 1 if a request is to be made and 0 otherwise). In the case of “maximum number of bits changed” types of signature updaters, a check is made to see if the snoop signature is less than or equal to the signature register (one comparison for each group). If all such comparisons are true, the address might be in the cache and the signature snoop request 1015 is made. The mask snoop request 1011 and the signature snoop request 1015 are AND-ed together in logic element 1016 to generate a snoop request signal 1017 . If this signal is 1, a snoop request will be generated unless it is ruled out by the snoop vector lists, or an applied range filter (see FIG. 7 ). However, specifically, such a snoop request cannot be ruled out by the result of a signature-mask filter from another stream register.
The signature register is set appropriately at the same time that the stream register is first set, or reset. For scoreboard types and max-types of signatures, the signature register is set to all zeros (indicating no bits different from the stream register).
The stream register filter relies upon knowing when the entire contents of a cache have been replaced, relative to a particular starting state—a cache wrap condition as referred to herein. A set-associative cache is considered to have wrapped when all of the sets within the cache have been replaced. Normally, some sets will be replaced earlier than others and will continue to be updated before all sets have been replaced and the cache has wrapped. Therefore, the starting point for cache wrap detection is the state of the cache sets at the time of the previous cache wrap.
In one embodiment, the cache is set-associative and uses a round-robin replacement algorithm, however other replacement implementations are possible. For instance, cache wrap detection may be achieved when the cache implements an arbitrary replacement policy, including least-recently-used and random. As referred to in the description to follow, a set-associative (SA) cache comprises some number of sets, where each set can store multiple lines (each with the same set index). The lines within a set are called “ways”. Hence, a 2-way set associative cache has two (2) lines per set. All of the ways within a set are searched simultaneously during a lookup, and only one of them is replaced during an update. Furthermore, a set can be partitioned such that a subset of the ways is assigned to each partition. For example, a 4-way SA cache may be partitioned into two 2-way SA caches. The virtual memory page table (and the translation lookaside buffer (TLB)) can provide a partition identifier that specifies which cache partition a particular memory reference is targeted at (both for lookup and update). The register that stores the way to be updated for a cache wrap needs to be big enough to store a way number. For example, 2 bits for a 4-way SA cache, or 5 bits for a 32-way SA cache. There is one such register per set because each set can wrap at a different time.
In one embodiment of the invention, the cache is partitionable into three partitions, with each partition including a contiguous subset of the cache ways, and that subset is the same within each cache set. Memory references are designated by the processor's memory management unit to be cached in one of the three partitions. Updates to a partition occur independently of the other partitions, so one partition can wrap long before the entire cache wraps. However, detecting the wrapping of a partition is identical to detecting the wrapping of the entire cache when the partition being updated is known. Thus, as referred to hereinafter, cache wrapping includes either partition wrapping or entire cache wrapping.
In order for external logic to detect cache updates, a cache must provide an indication that an update is occurring and which line is being overwritten. The logic of the preferred embodiment assumes that this information is provided by means of a set specification, a way specification and an update indicator.
FIGS. 19( a ) and 19 ( b ) depict the cache wrap detection logic of the preferred embodiment for an N-way set-associative cache. In this embodiment, it is assumed that updates to a set are always performed in round-robin order. That is, the “victim” way chosen to be overwritten is always the one following the previously-overwritten one.
FIG. 19( a ) particularly depicts one embodiment of logic implemented for detecting the wrap of a single partition of a single set (set “i” in the embodiment depicted) within the logic block 920 . When this logic has detected a wrap in set i, it asserts the set_wrap(i) signal 910 . FIG. 19( b ) shows how the individual set_wrap(i) 910 signals from all N sets of the cache are combined with a logic OR function to produce the cache_wrap 912 signal, which asserts when the entire cache (i.e. all sets) have wrapped. It is understood that the logic and circuitry depicted in FIGS. 19( a ) and 19 ( b ) is only one example implementation and skilled artisans will recognize that many variations and modifications may be made thereof without departing from the scope of the invention.
On the left-hand side of FIG. 19( a ), there is depicted a partition detection logic block 922 that determines when a cache update falls within the partition that is being monitored for wrapping. This logic assumes that the partition extends from a way specified by “lower” 916 to the way specified by “upper” 918 . Therefore, the remainder of the logic that detects set wraps partition only changes state when there is an update, and that update falls within the partition of interest. Note that the partition detection logic 922 is common to all N copies of the set wrap detection logic.
Within the set wrap detection logic, the common partition update indicator is further qualified to act only when the update is to the particular set i associated with that logic. This is done by matching the set specifier 924 to the index of the set wrap detection logic 926 .
The remainder of the logic circuits function as follows: Assume that initially, the flip-flop driving set_wrap(i) 930 is clear, indicating that the set has not wrapped, and the register 928 includes the way that must be updated to complete a set wrap. In this state, the register retains its value. When a cache update occurs, where the way 914 matches the contents of the register 928 , as determined by a comparator device 919 , the flip-flop driving set_wrap(i) 930 is loaded with logic 1, causing set_wrap(i) 910 to assert. Thereafter, cache updates cause the updated way 914 to be stored in the register 928 , so the register 928 effectively tracks those updates. When all cache sets have wrapped, the combined cache_wrap 912 signal is asserted as shown in FIG. 19 ( b ), causing the flip-flop 930 to clear (assuming Reset takes precedence over Load). This returns the circuit to the initial state, with the register 928 storing the way that must be updated to indicate the next set wrap.
It is thus understood that there is one register per set that stores the number of a way and when that way is overwritten, then the set has wrapped. However, the sets wrap at different times (depending on the access pattern), and the entire cache is not considered to have wrapped until all sets have wrapped. At that point, the state of the victim way pointers (i.e. pointer to the last way that was overwritten; one per set) becomes the new initial condition for detecting the next cache wrap. The first embodiment accommodates this requirement by having the register described above keep track of ways that are overwritten between the time that it has wrapped and the time that the entire cache has wrapped. Then when the whole cache wraps, it stops tracking the overwritten ways and becomes the basis for comparison for determining when the set wraps again.
In a second embodiment of the cache wrap detection logic, a counter is implemented, so when the whole cache wraps, all set counters are reset to the number of ways in the partition. As ways are overwritten, the counters count down; and when a counter reaches zero, then the corresponding set has wrapped. When all counters reach zero, then the cache has wrapped and the process starts again.
According to this second embodiment, the set wrapped detection logic provided within the box 920 depicted in FIG. 19( a ) is thus based on a loadable counter, rather than a register and comparator. This logic is shown in FIG. 20 . In this logic, a down-counter device 932 is loaded with the number of ways in the partition 936 while set_wrap(i) 910 is asserted (assuming Load takes precedence over Down). When all sets have wrapped and cache_wrap 912 is asserted, the flip-flop 930 driving set_wrap(i) is cleared and the counter 932 is no longer loaded. Thereafter, each update to the partition 914 and set 934 tracked by the logic cause the counter 932 to count down by one. Once it reaches zero, the flip-flop 930 is loaded with logic 1, causing set_wrap(i) 910 to be asserted, and returning the logic to the initial state.
A third embodiment of the cache wrap detection logic, shown in FIG. 21 , will work with a cache that implements any replacement policy, including least recently used and random. In this case, a scoreboard 940 is used to keep track of the precise cache way 914 that is overwritten. Specifically, it is used to detect the first write to any way. In addition, a counter 942 keeps track of the number of times that a scoreboard bit was first set (i.e. goes from 0 to 1). It does this by only counting scoreboard writes where the overwritten bit (old_bit) is zero. The counter 942 is pre-loaded to the partition size 936 (i.e. number of ways in the partition), so once this counter reaches zero, the entire cache partition has wrapped. This is indicated by the cache_wrap 912 signal being asserted, causing the counter 942 to be reloaded (assuming Load takes precedence over Down) and the scoreboard 940 to be cleared (i.e. reset).
While the preferred embodiment of the present invention is practiced in conjunction with a write-through cache, wherein snooping only occurs on write requests, and the results of a snoop action are the invalidation of a local data copy, the invention is not so limited. For instance, the invention can also be practiced in conjunction with write-back cache organizations. In accordance with a write-back cache, a coherence protocol will include additional transactions, e.g., including but not limited to, those in accordance with the well-known MESI protocol, or other coherence protocols. In accordance with a coherence protocol for writeback caches, read transaction on remote processors cause snoop actions to determine if remote caches have the most recent data copy in relation to the main memory. If this is the case, a data transfer is performed using one of several ways, including but not limited to, causing the processor having the most recent data to write the data to main memory, directly transferring the data from the owner of the most recent copy to the requestor, or any other method for transferring data in accordance with a snoop intervention of a specific protocol. In accordance with this invention, a snoop filtering action can be used to determine an accelerated snoop response.
While the preferred embodiments have been described in terms of fixed interconnection topologies, and fixed snoop filtering operations, in one aspect of the present invention the snoop filtering subsystem has programmable aspects at one, or more, levels of the snoop filter hierarchy. In accordance with one embodiment of a programmable feature of the present invention, the interconnect topology is selected. In accordance with one variety of programmable topology, the one-to-one and one-to-many relationship between different filters in a topology is selectable. In accordance with another aspect of a programmable embodiment, the order in which a first snoop filter, and then a second snoop filter is accessed, or alternatively, a first or second snoop filter are accessed in parallel, is configurable under program control.
In accordance with yet another aspect of yet another embodiment of a programmable feature of the present invention, the operation of a filter subunit is programmable. This can be in the form of configurable aspects of a snoop filter, e.g., by configuring programmable aspects such as associativity of the cache being snooped, the coherence architecture being implemented, and so forth. In another aspect of a programmable filter subunit, the filter subunit is implemented in programmable microcode, whereby a programmable engine executes a sequence of instructions to implement the aspects of one or more preferred embodiments described herein. In one aspect, this is a general microcode engine. In another aspect, this is an optimized programmable microcode engine, the programmable microcode engine having specialized supporting logic to detect snoop filter-specific conditions, and, optionally, specialized operations, such as “branch on cache wrap condition”, specialized notification events, e.g., in the form of microcode engine-specific exceptions being delivered to the microcode engine, such as “interrupt on cache wrap condition”, and so forth.
In yet another embodiment of a programmable feature of the present invention, parts or all of the aspects of snoop filtering are implemented incorporating a programmable switch matrix, or a programmable gate array fabric. In one of these aspects, the routing between snoop subunits is performed by configuring the programmable switch matrix. In another aspect of this programmable embodiment, the actions of the snoop filter unit are implemented by configuring a programmable gate array logic block. In anther aspect of the present invention, the entire snoop filter block is implemented by configuring at least one field-programmable gate array cell.
In accordance with another embodiment of a programmable feature of the present embodiments, one of more snoop filter subsystems can be disabled, certain snoop filtering steps can be bypassed, or snoop filtering can be disabled altogether. In one embodiment, this is achieved by writing the configuration of the snoop filter in a configuration register. In another embodiment, this configuration can be selected by input signals.
While there has been shown and described what is considered to be preferred embodiments of the invention, it will, of course, be understood that various modifications and changes in form or detail could readily be made without departing from the spirit of the invention. It is therefore intended that the invention be not limited to the exact forms described and illustrated, but should be constructed to cover all modifications that may fall within the scope of the appended claims.
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A method and apparatus for supporting cache coherency in a multiprocessor computing environment having multiple processing units, each processing unit having one or more local cache memories associated and operatively connected therewith. The method comprises providing a snoop filter device associated with each processing unit, each snoop filter device having a plurality of dedicated input ports for receiving snoop requests from dedicated memory writing sources in the multiprocessor computing environment. Each snoop filter device includes a plurality of parallel operating port snoop filters in correspondence with the plurality of dedicated input ports, each port snoop filter implementing one or more parallel operating sub-filter elements that are adapted to concurrently filter snoop requests received from respective dedicated memory writing sources and forward a subset of those requests to its associated processing unit.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a semiconductor laser, and more particularly to a semiconductor laser having a so-called simplified antiresonant reflecting optical waveguide (hereinafter referred to as S-ARROW) structure, which is constructed so as to confine a basic lateral mode light between a pair of high refractive index layers, each extending with a gap therebetween.
[0003] The present invention relates also to a method of fabricating a semiconductor laser having the S-ARROW structure.
[0004] 2. Description of Related Arts
[0005] A semiconductor laser has been predominantly used as a light source for use in optical communication, a light source for use in an optical disc and the like by use of property that a laser light emitted therefrom can be collected up to a diffraction limitation. However, all light radiated from the semiconductor laser can never be collected up to the diffraction limitations thereof. Only light having well matched phases is collected at a light emission end of the semiconductor laser. The semiconductor laser in a condition of being capable of emitting such a light is known as one performing light emission in a basic lateral mode. Under condition that light of various phase is being emitted mixedly, in other words, under condition that high ordered lateral mode light is being mixedly emitted, the light cannot be collected up to a diffraction limitation.
[0006] It has been widely known that the foregoing basic lateral mode operation is more stable as an area of a light emission section is made smaller so that it is difficult for the high order lateral mode light to be mixedly present. For this reason, a size of a waveguide path in the semiconductor laser is set to 1 μm or less in a direction of a thickness thereof, and to about 2 to about 4 μm in a direction in parallel with a light emission layer thereof. It has been well known by experience that a semiconductor laser device emitting a light in a basic lateral mode more stably can be manufactured with a high yield as a width of the waveguide path in the direction in parallel with the light emission layer is made narrower.
[0007] However, if the area of the light emission section is made small by narrowing the lateral width of the waveguide path, an increase in light density in a light emission end of the semiconductor laser is inevitably brought about. The increase in the light density in the light emission end incurs deterioration of materials constituting the semiconductor laser, resulting in reduction in the life of the device.
[0008] In other words, the stabilization of the basic lateral mode (the small section area of the waveguide path) and an increase in light output (the large section area of the waveguide path) are mutually incompatible. Accordingly, to overcome this limitation is an important problem in researching and developing existing semiconductor lasers.
[0009] As disclosed in IEEE PHOTONICS TECHNOLOGY LETTERS, Vol. 10, No. 8, August 1998, the S-ARROW structure has been proposed as one idea to solve the problem. The S-ARROW structure has a light emission width of about 6 μm, and the width of the light emission section of this structure can be set to be 1.5 to 2 times as large as that of the conventional structure, so that it is anticipated that the maximum light output will be improved.
[0010] The reason why the semiconductor laser adopting the S-ARROW structure emits light in the basic lateral mode will be explained below.
[0011] A cross section of the principal portion of the semiconductor laser having the S-ARROW structure, that is, a shape in a cross section perpendicular to the waveguide direction, is shown in FIG. 18A. This semiconductor laser comprises an n-GaAs substrate 39 ; a lower clad layer 38 made of n-InGaP, formed on the n-GaAs substrate 39 ; a SCH (separate-cofinement-heterostructure) structural layer 37 made of InGaAsP, which includes an InGaAs quantum well activation layer; upper clad layers 36 and 32 made of p-InGaP; an etching stop layer 35 made of n-GaAs; a current blocking layer 34 made of n-AlInP; guide portions 33 of a thickness of e.g. 0.25 μm, made of n-GaAs; and a contact layer 31 made of p-GaAs.
[0012] In the above-described structure, since GaAs constituting the above-described guide portion 33 possesses a refractive index higher than that of a periphery of the guide portions 33 , an equivalent refractive index in a direction in parallel with the SCH structural layer 37 has a distribution high in the guide portion 33 and low in other portions, as shown in FIG. 18B.
[0013] In such a waveguide structure, with respect to the width A of each of the two guide portions 33 , a dimension is selected so that while only light in a basic lateral mode is confined between these guide portions 33 , light in a high ordered lateral mode is not confined therebetween but escapes outside each of the guide portions 33 . According to the literature cited above, the width A of the guide portions 33 is set to 0.85 μm, and the width B of the groove formed by the guide portions 33 is set to 6.5 μm.
[0014] Due to the effect of the current blocking layer 34 , a current producing a gain of the laser is injected only between the two guide portions 33 , and the gain relevant to the laser light is generated only between the guide portions 33 .
[0015] Accordingly, only the light in the basic lateral mode is confined between the guide portions 33 , and hence a sufficient gain can be obtained. On the other hand, since the light in the high order lateral mode is not confined between the guide portions 33 , a gain cannot be obtained. As a natural consequence of such a fact, the light in the basic lateral mode is given priority in emission, and the semiconductor laser operates in a stable basic lateral mode until the high light output.
[0016] Heretofore, however, the fabrication of the semiconductor laser having the S-ARROW structure has inevitably shown a low yield for the following reason, causing a serious problem in mass production of the semiconductor lasers. To explain this reason, a method of fabricating the semiconductor laser having the S-ARROW structure will first be described with reference to FIGS. 19 to 22 .
[0017] As shown in FIG. 19, on the n-GaAs substrate 39 , there are sequentially grown the lower clad layer 38 made of n-InGaP, the SCH (Separate-confinement-heterostructure) structural layer 37 made of InGaAsP, which includes the InGaAs quantum well activation layer, the upper clad layer 36 made of p-InGaP, the etching stop layer 35 made of n-GaAs, the current blocking layer 34 made of n-AlInP, and the guide portion 33 having a thickness of 0.25 μm, which is made of n-GaAs by use of an organometallic growth method.
[0018] The GaAs layer is partially removed by a photolithography step and an etching step while leaving the part of the GaAs layer functioning as the guide portion 33 , thus obtaining the sectional structure shown in FIG. 20.
[0019] Furthermore, as shown in FIG. 21, a resist pattern 40 is formed at portions other than that corresponding to a groove having the width B (see FIG. 18) by use of a photolithography step.
[0020] Thereafter, by use of the resist pattern 40 as a mask, the semiconductor layers including the guide portion 33 , the current blocking layer 34 and the etching stop layer 35 are sequentially etched so as to be removed until the upper clad layer 36 made of p-InGaP is exposed. Thus, the sectional structure shown in FIG. 22, in which a pair of resist patterns 40 are formed, is obtained.
[0021] Thereafter, the resist pattern 40 is removed, and then the upper clad layer 32 made of p-InGaP and the contact layer 31 made of p-GaAs are formed by a crystal growth method, thus obtaining the semiconductor laser having the structure shown in FIG. 18.
[0022] In the conventional method described above, the photolithography steps were performed two times. The pair of resist patterns 40 had a size of about 01 μm and were required to be coincident with each other with a very high precision. If this precision is low, the widths of the guide portions 33 differ from each other, and the guide portions 33 cannot have an original width. Moreover, formation positions of the guide portions 33 deviate from the predetermined positions.
[0023] In the semiconductor laser fabricated in such a manner, since light other than that in the basic lateral mode remains between the guide portions 33 , the semiconductor laser emits light in a mode other than the basic lateral mode. Furthermore, the light in the basic lateral mode is not sufficiently guided between the guide portions, resulting in a drawback that a threshold value of oscillation current in the basic lateral mode increases. To be concrete, even when the positions and widths of the guide portions 33 deviate from predetermined values by about 0.1 to 0.2 μm, deterioration in electric characteristics of the semiconductor laser is brought about.
SUMMARY OF THE INVENTION
[0024] The present invention was conceived in view of the foregoing circumstances, and the object is to provide a semiconductor laser having a S-ARROW structure, which has a high precision in shapes of a pair of highly refractive guide portions, thus emitting light in a basic lateral mode stably, and is capable of keeping a threshold value of oscillation current in the basic lateral mode low.
[0025] Another object of the present invention is to provide a method of fabricating such a semiconductor laser.
[0026] A method of fabricating a semiconductor laser according to the present invention having a structure in which an equivalent refractive index of two portions disposed apart from each other is higher than that of adjacent portions to these portions on a plane perpendicular to a waveguide direction as well as in a direction in parallel with an activation layer, comprises the steps of:
[0027] forming the activation layer and a plurality of layers in parallel with the activation layer;
[0028] forming a first groove penetrating through at least some of the plurality of layers;
[0029] selectively etching a specified layer among the layers through which the first groove penetrates, to a predetermined position toward both sides from the first groove, thus forming a pair of second grooves; and
[0030] filling up the second grooves with a material having a refractive index higher than at of the specified layer, thus forming two portions having the high equivalent refractive index.
[0031] A first semiconductor laser of the present invention fabricated according to the method, which has a structure in which an equivalent refractive index of two portions disposed apart from each other is higher than that of adjacent portions to these portions in a direction perpendicular to a waveguide direction as well as in parallel with an activation layer, comprises:
[0032] the activation layer and a plurality of layers in parallel with the activation layer,
[0033] wherein a first groove is formed penetrating through at least some of the plurality of layers;
[0034] a pair of second grooves extending from the first groove to predetermined positions toward both sides are formed in a specified layer among the layers through which the first groove penetrates;
[0035] the second grooves are filled up with a material having a refractive index higher than that of the specified layer, and thus two portions having the high equivalent refractive index are formed; and
[0036] another layer is formed in a state where the two portions contact with the material having the higher refractive index left on a surface portion of the first groove.
[0037] A second semiconductor laser of the present invention fabricated according to the method, which has a structure in which an equivalent refractive index of two portions disposed apart from each other is higher than that of adjacent portions to these portions in a direction perpendicular to a waveguide direction as well in parallel with an activation layer, comprises:
[0038] the activation layer and a plurality of layers in parallel with the activation layer,
[0039] wherein a first groove is formed penetrating through at least some of the plurality of layers;
[0040] a pair of second grooves extending from the first groove to predetermined positions toward both sides are formed in a specified layer among the layers through which the first groove penetrates;
[0041] the second grooves are filled up with a material having a refractive index higher than that of the specified layer, and thus two portions having the high equivalent refractive index are formed; and
[0042] another layer made of a different material from the high refractive material is formed in a state where the two portions contact with a surface portion of the first groove.
[0043] A third semiconductor laser of the present invention fabricated according to the method, which has a structure in which an equivalent refractive index of two portions disposed apart from each other is higher than that of adjacent portions to these portions in a direction perpendicular to a waveguide direction as well as in parallel with an activation layer, comprises:
[0044] the activation layer and a plurality of layers in parallel with the activation layer,
[0045] wherein a first groove is formed penetrating through at least some of the plurality of the layers;
[0046] a pair of second grooves extending from the first groove to predetermined positions toward both sides are formed in a specified layer among the layers through which the first groove penetrates;
[0047] the second grooves are filled up with a material having a refractive index higher than that of the specified layer; and
[0048] layers made of a material having a low refractive index are laminated on the material exposed in the first groove, this refractive index being lower than that of the exposed material, and thus two portions having the high equivalent refractive index are formed outside the material having the low refractive index.
[0049] Note that in the third semiconductor laser, the material having the high refractive index and the material having the low refractive index may be two separate materials, each having a constant refractive index, or alternatively one refractive index distribution material in which a refractive index gradually varies in a lamination direction of both materials.
[0050] In the method of fabricating each of the semiconductor lasers according to the present invention, the first groove penetrating the layers in parallel with the activation layer is first formed, and then the pair of second grooves are formed by selectively etching the specified layer among the layers through which the first groove penetrates from the first groove to the predetermined positions toward both sides from the first groove. Accordingly, the pair of second grooves are formed at etching rates naturally equal to each other, so depths from the first groove become equal to each other. Thus, widths of the materials having the high refractive index filled up in the pair of the second grooves, that is, widths of guide portions, are formed equal to each other in a self-alignment manner with a high precision.
[0051] Accordingly, the semiconductor laser fabricated according to the method of the present invention has the pair of the guide portions made of the high refractive index material, which are formed to shapes with a high precision, and can emit light in a basic lateral mode stably, thus keeping a threshold value of oscillation current in a basic lateral mode low.
BRIEF DESCRIPTION OF THE DRAWINGS
[0052] [0052]FIGS. 1A and 1B are schematic sectional views showing a semiconductor laser according to a first embodiment and an equivalent refractive index distribution thereof.
[0053] [0053]FIG. 2 is a drawing showing a manufacturing step of the semiconductor laser of FIGS. 1A and 1B.
[0054] [0054]FIG. 3 is a drawing showing a manufacturing step of the semiconductor laser of FIGS. 1A and 1B.
[0055] [0055]FIG. 4 is a drawing showing a manufacturing step of the semiconductor laser of FIGS. 1A and 1B.
[0056] [0056]FIG. 5 is a drawing showing a manufacturing step of the semiconductor laser of FIGS. 1A and 1B.
[0057] [0057]FIGS. 6A and 6B are drawing s showing a manufacturing step of the semiconductor laser of FIGS. 1A and 1B.
[0058] [0058]FIGS. 7A and 7B are a schematic sectional view showing a semiconductor laser according to a second embodiment and an equivalent refractive index distribution thereof.
[0059] [0059]FIG. 8 is a drawing showing a manufacturing step of the semiconductor laser of FIGS. 7A and 7B.
[0060] [0060]FIG. 9 is a drawing showing a manufacturing step of the semiconductor laser of FIGS. 7A and 7B.
[0061] [0061]FIG. 10 is a drawing showing a manufacturing step of the semiconductor laser of FIGS. 7A and 7B.
[0062] [0062]FIG. 11 is a drawing showing a manufacturing step of the semiconductor laser of FIGS. 7A and 7B.
[0063] [0063]FIG. 12 is a drawing showing a manufacturing step of the semiconductor laser of FIGS. 7A and 7B.
[0064] [0064]FIGS. 13A and 13B are schematic sectional views showing a semiconductor laser according to a third embodiment and an equivalent refractive index distribution thereof.
[0065] [0065]FIG. 14 is a drawing showing a manufacturing step of the semiconductor laser of FIGS. 13A and 13B.
[0066] [0066]FIG. 15 is a drawing showing a manufacturing step of the semiconductor laser of FIGS. 13A and 13B.
[0067] [0067]FIG. 16 is a drawing showing a manufacturing step of the semiconductor laser of FIGS. 13A and 13B.
[0068] [0068]FIGS. 17A and 17B are drawing s showing a manufacturing step of the semiconductor laser of FIGS. 13A and 13B.
[0069] [0069]FIGS. 18A and 18B are schematic sectional views showing a conventional semiconductor laser having an S-ARROW structure and an equivalent refractive index distribution thereof.
[0070] [0070]FIG. 19 is a drawing showing a manufacturing step of the semiconductor laser of FIGS. 18A and 18B.
[0071] [0071]FIG. 20 is a drawing showing a manufacturing step of the semiconductor laser of FIGS. 18A and 18B.
[0072] [0072]FIG. 21 is a drawing showing a manufacturing step of the semiconductor laser of FIGS. 18A and 18B.
[0073] [0073]FIG. 22 is a drawing showing a manufacturing step of the semiconductor laser of FIGS. 18A and 18B.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0074] Embodiments of the present invention will be described below with reference to the accompanying drawings. FIGS. 1A and 1B show a shape in a section perpendicular to a waveguide direction of a semiconductor laser according to a first embodiment of the present invention and an equivalent refractive index distribution thereof. FIGS. 2 to 5 and FIGS. 6A and 6B show sequential steps for fabricating the semiconductor laser.
[0075] The semiconductor laser as shown in FIG. 1A comprises an n-GaAs substrate 23 ; a lower clad layer 22 made of n-InGaP; a SCH structural layer 21 made of InGaAsP including an InGaAs quantum well activation layer; a first upper clad layer 20 made of p-InGaP; a first etching stop layer 19 made of p-GaAs; a second etching stop layer 18 made of n-InGaP; a first current blocking layer 17 made of n-GaAs; a second current blocking layer 16 made of n-InGaAsP; a third current blocking layer 15 made of n-AlGaAs; a cover layer 14 made of n-GaAs; a guide layer 13 made of p-GaAs; a second upper clad layer 12 made of p-AlGaAs; and a contact layer 11 made of p-GaAs. Furthermore, an n-side electrode 24 is formed on the rear surface of the n-GaAs substrate 23 , and a p-side electrode 25 is formed over the contact layer 11 .
[0076] Here, semiconductors constituting the second current blocking layer 16 and the third current blocking layer 15 have a composition having a refractive index lower than that of GaAs. In this structure of the semiconductor laser, the layers made of GaAs having a high refractive index above the first upper clad layer 20 determines a refractive index distribution in a horizontal direction, that is, in a direction in parallel with the SCH structural layer 21 . Note that since the GaAs layers disposed above the third current blocking layer 15 are distant from a light emission portion, these GaAs layers have less effect on the refractive index distribution. Accordingly, an equivalent refractive index distribution is equal to the refractive index distribution of GaAs constituting the first current blocking layer 17 and the guide layer 13 shown by slanted lines in FIG. 6A. As a matter of course, the portion C having the thick GaAs layer has a refractive index higher than those of other portions. This structure of the semiconductor laser has an equivalent refractive index distribution shown in FIG. 1B when viewed in the horizontal direction, and it is understood that this structure thereof is identical to a waveguide structure of the foregoing S-ARROW structure.
[0077] Next, a method of fabricating the semiconductor laser will be described with reference to FIG. 2 to FIGS. 6A and 6B.
[0078] As shown in FIG. 2, by use of an organometallic growth method, on the n-GaAs substrate 23 , there is sequential formation of the lower clad layer 22 made of n-InGaP; the SCH structural layer 21 made of InGaAsP including the InGaAs quantum well activation layer; the first upper clad layer 20 made of p-InGaP; the first etching stop layer 19 made of p-GaAs; the second etching stop layer 18 made of n-InGaP; the first current blocking layer 17 made of n-GaAs; a second current blocking layer 16 made of n-InGaAsP; a third current blocking layer 15 made of n-AlGaAs; and a cover layer 14 made of n-GaAs.
[0079] Subsequently, as shown in FIG. 3, a resist pattern 70 is formed on parts of the cover layer 14 other than a groove portion by a photolithography step. Furthermore, as shown in FIG. 4, the cover layer 14 , the third current blocking layer 15 , the second current blocking layer 16 , the first current blocking layer 17 and the second etching stop layer 18 are etched and removed by a chemical etching method. Thus, a first groove 71 extending to a direction intersecting the surface of the substrate 23 is formed.
[0080] Next, the multi-layered semiconductor film is dipped in an etching solution of tartaric acid series offering a fast etching rate only for InGaAsP, and the current blocking layer 16 is etched to predetermined positions from the first groove 71 toward both left and right directions. Furthermore, the resist pattern 70 is also removed. Thus, the sectional structure as shown in FIG. 5 is obtained. Here, a groove extending toward a direction in parallel with the SCH structure layer 21 , the groove being obtained by removing the current blocking layer 16 in the above-described manner, shall be referred to as a second groove 72 .
[0081] Furthermore, as shown in FIG. 6A, the guide layer 13 made of p-GaAs, the second upper clad layer 12 made of p-AlGaAs and the contact layer 11 made of p-GaAs are formed by crystal growth. At this time, since growth material gas easily enters into the narrow second groove 72 corresponding to the guide portion C by use of a vapor deposition method, the second groove 72 can be filled up with the guide layer 13 .
[0082] Thereafter, the p-side electrode 25 is formed over the contact layer 11 . The substrate 23 is polished, and then the n-side electrode 24 is formed. Furthermore, a high-reflectance coat and a low-reflectance coat are formed on a resonator plane obtained by cleaving a sample. Thereafter, when the resultant structure is processed to a chip, the semiconductor laser device shown in FIG. 1 is obtained.
[0083] This semiconductor laser device is mounted onto a heat sink in a junction down manner with electrically conductive solder material such as In, and the semiconductor laser device undergoes wire-bonding for the n-side electrode 24 , thus completing the semiconductor laser apparatus.
[0084] In this embodiment, since the second grooves 72 are formed by etching the portions of the current blocking layer 16 extending from the first groove 71 to predetermined positions toward left and right directions thereof, the right and left second grooves 72 extend to the positions distant from the first groove 71 by equal distances. Accordingly, the widths of the portions of the guide layers 13 filled in the right and left second grooves 72 are equal to each other with a high precision in a self-alignment manner. Thus, the semiconductor laser having the S-ARROW structure emits light in the basic lateral mode stably, and can keep a threshold value of oscillation current in the basic lateral mode low.
[0085] To be concrete, the semiconductor laser device having the above-described constitution oscillates with a resonator length of 1.5 mm and an oscillation wavelength of 980 nm, and operates up to an output of 0.5 W on a light output vs. current characteristic without any trouble. Furthermore, the semiconductor laser device can obtain a stable light output without any disarranged near field pattern even at the time when the semiconductor laser device is mounted on an actual system. According to the fabrication method described above, the semiconductor laser device having such a characteristic can be obtained with a good reproducibility.
[0086] Next, a second embodiment of the present invention will be described. FIG. 7A shows a shape of a section of a semiconductor laser according to the second embodiment of the present invention, which is perpendicular to the waveguide direction, and FIG. 7B shows an equivalent refractive index distribution thereof. FIGS. 8 to 12 show steps for fabricating the semiconductor laser in order.
[0087] In the semiconductor laser as shown in FIG. 7A, on an n-GaAs substrate 60 , there are formed a lower clad layer 59 made of n-InGaP, a SCH structural layer 58 made of InGaAsP, which includes an InGaAs quantum well activation layer, a first upper clad layer 57 made of p-InGaP, a first etching stop layer 56 made of n-GaAs, a first current blocking layer 55 made of n-AlGaAs, a second current blocking layer 54 made of n-InGaAsP, a third current blocking layer 53 made of n-AlGaAs, a guide layer 50 made of n-GaAs, a second upper clad layer 52 made of p-InGaP, and a contact layer 51 made of p-GaAs. An n-side electrode 61 is formed on the rear surface of the n-GaAs substrate 60 , and a p-side electrode 62 is formed over the contact layer 51 .
[0088] Here, semiconductors constituting the first current blocking layer 55 , the second current blocking layer 54 and the third current blocking layer 53 respectively have a composition having a refractive index lower than that of GaAs. In this structure of the semiconductor laser, the GaAs guide layer 50 having a high refractive index determines a refractive index distribution in a horizontal direction, that is, a direction in parallel with the SCH structural layer 58 . Accordingly, this structure of the semiconductor laser has an equivalent refractive index distribution shown in FIG. 7B when viewed in the horizontal direction, and it is understood that this structure thereof is identical to a waveguide structure of the foregoing S-ARROW structure.
[0089] Next, a method of fabricating the semiconductor laser will be described with reference to FIGS. 8 to 12 . As shown in FIG. 8, by use of an organometallic growth method, on the n-GaAs substrate 60 , there are sequentially formed the lower clad layer 59 made of n-InGaP, the SCH structural layer 58 made of InGaAsP including the InGaAs quantum well activation layer, the first upper clad layer 57 made of p-InGaP, the first etching stop layer 56 made of n-GaAs, the first current blocking layer 55 made of n-AlGaAs, the second current blocking layer 54 made of n-InGaAsP, the third current blocking layer 53 made of n-AlGaAs, and the protection layer 63 made of GaAs.
[0090] Subsequently, as shown in FIG. 9, a resist pattern 64 is formed on parts of the cover layer 14 other than a groove portion by a photolithography step. Furthermore, the protection layer 63 , the third current blocking layer 53 , the second current blocking layer 54 and the first current blocking layer 55 are etched and removed by a chemical etching method. Thus, a first groove 71 extending to a direction intersecting the surface of the substrate 60 is formed.
[0091] Next, the multi-layered semiconductor film is dipped in an etching solution of tartaric acid series offering a fast etching rate only for InGaAsP, and the second current blocking layer 54 is etched to predetermined positions from the first groove 71 toward both left and right directions. Furthermore, the resist pattern 64 is also removed. Thus, the sectional structure as shown in FIG. 10 is obtained. Here, a groove extending toward a direction in parallel with the SCH structure layer 58 , the groove being obtained by removing the second current blocking layer 54 in the above-described manner, shall be referred to as a second groove 72 .
[0092] Furthermore, as shown in FIG. 11, the guide layer 50 made of GaAs is formed by use of a vapor deposition method. At this time, since growth material gas easily enters also into the narrow second groove 72 with use of the vapor deposition method, the second groove 72 can be filled up with the guide layer 50 .
[0093] Next, the multi-layered semiconductor film formed in the above-described manner is dipped in an etching solution (a mixture of ammonia and hydrogen peroxide liquid) having a property which dissolves GaAs. Since the properties of this etching solution are that it never dissolves InGaAsP and offers a remarkably lowered dissolving rate for the guide layer 50 , that is a GaAs thin layer sandwiched by InGaAsP, the structure shown in FIG. 12 can be obtained.
[0094] Thereafter, the second upper clad layer 52 made of p-InGaP and the contact layer 51 made of p-GaAs are formed by a vapor deposition method, and the p-side electrode 62 is formed over the contact layer 51 . The substrate 60 is polished, and then the n-side electrode 61 is formed. Furthermore, a high-reflectance coat and a low-reflectance coat are formed on a resonator plane obtained by cleaving a sample. Thereafter, when the resultant structure is processed to a chip, the semiconductor laser device shown in FIG. 7 is obtained.
[0095] In this embodiment, since the second grooves 72 are formed by etching the portions of the second current blocking layer 54 extending from the first groove 71 to predetermined positions toward left and right directions thereof, the right and left second grooves 72 extend to the positions distant from the first groove 71 by equal distances. Accordingly, the widths of the portions of the guide layers 50 filled in the right and left second grooves 72 are equal to each other with a high precision in a self-alignment manner. Thus, the semiconductor laser having the S-ARROW structure emits light in the basic lateral mode stably, and can keep a threshold value of oscillation current in the basic lateral mode low.
[0096] Also the semiconductor laser device having the above-described constitution oscillates with a resonator length of 1.5 mm and an oscillation wavelength of 980 nm, and operates up to an output of 0.5 W on a light output vs. current characteristic without any trouble. Furthermore, the semiconductor laser device can obtain a stable light output without any disarranged near field pattern even when the semiconductor laser device is mounted on an actual system. According to the fabrication method described above, the semiconductor laser device having such a characteristic can be obtained with a good reproducibility.
[0097] Next, a third embodiment of the present invention will be described. FIG. 13A shows a shape of a section of a semiconductor laser according to the third embodiment of the present invention, which is perpendicular to the waveguide direction, and FIG. 13B shows an equivalent refractive index distribution thereof. FIGS. 14 to 16 and FIG. 17A and 17B show steps for fabricating the semiconductor laser in order.
[0098] In the semiconductor laser as shown in FIG. 13A, on an n-GaAs substrate 93 , there are formed a lower clad layer 91 made of n-InGaP, a SCH structural layer 90 made of InGaAsP, which includes an InGaAs quantum well activation layer, a first upper clad layer 89 made of p-InGaP, an etching stop layer 88 made of p-GaAs, a first current blocking layer 86 made of n-InGaAsP, a second current blocking layer 85 made of n-AlGaAs, a cover layer 84 made of n-GaAs, a guide layer 83 made of p-GaAs, a reverse guide layer 92 made of p-AlGaAs, a second upper clad layer 82 made of p-AlGaAs, and a contact layer 81 made of p-GaAs. An n-side electrode 94 is formed on the rear surface of the n-GaAs substrate 93 , and a p-side electrode 95 is formed over the contact layer 81 .
[0099] Here, a semiconductor constituting the current blocking layer 86 has a composition having a refractive index lower than that of GaAs. A semiconductor constituting a reverse guide layer 92 made of p-AlGaAs has a composition having a refractive index lower than the current blocking layer 85 made of n-AlGaAs.
[0100] Therefore, in this structure of the semiconductor laser, a portion having a low refractive index shown by dotted lines 101 in FIG. 17 and a portion having a high refractive index shown by slanted lines 102 in FIG. 17 determine a refractive index distribution in the horizontal direction, that is, a direction in parallel with the SCH structural layer 90 . Since the semiconductors having the high and low refractive index overlap in the central portion of the groove, the refractive indexes are cancelled, while only a portion having a high refractive index exists in the scooped portion D. Accordingly, this structure of the semiconductor laser has an equivalent refractive index distribution shown in FIG. 13B when viewed in the horizontal direction, and it is understood that this structure thereof is identical to a waveguide structure of the foregoing S-ARROW structure.
[0101] Next, a method of fabricating the semiconductor laser will be described with reference to FIG. 14 to 16 and FIGS. 17A and 17B.
[0102] As shown in FIG. 14, by use of an organometallic growth method, on the n-GaAs substrate 93 , there are sequentially grown the lower clad layer 91 made of n-InGaP, the SCH structural layer 90 made of InGaAsP including the InGaAs quantum well activation layer, the first upper clad layer 89 made of p-InGaP, the etching stop layer 88 made of p-GaAs, the first current blocking layer 86 made of n-InGaAsP, a second current blocking layer 85 made of n-AlGaAs, and the cover layer 84 made of n-GaAs.
[0103] Subsequently, as shown in FIG. 15, a resist pattern 110 is formed on the cover layer 84 other than a portion to be etched to form a groove portion using a photolithography step. Furthermore, the cover layer 84 made of n-GaAs, the second current blocking layer 85 made of n-AlGaAs and the first current blocking layer 86 made of n-InGaAsP are etched and removed by a chemical etching method. Thus, the first groove 71 extending to a direction intersecting the surface of the substrate 60 is formed.
[0104] Next, the multi-layered semiconductor film is dipped in an etching solution of tartaric acid series offering a fast etching rate only for InGaAsP, and the first current blocking layer 86 is etched to predetermined positions from the first groove 71 toward both left and right directions. Furthermore, the resist pattern 110 is also removed. Thus, the sectional structure as shown in FIG. 16 is obtained. Here, the groove extending toward a direction in parallel with the SCH structure layer 90 , the groove being obtained by removing the first current blocking layer 86 in the above-described manner, shall be referred to as a second groove 72 .
[0105] Furthermore, as shown in FIG. 17A, the guide layer 83 made of p-GaAs, the reverse guide layer 92 made of p-AlGaAs, the clad layer 82 made of p-AlGaAs and the contact layer 81 made of p-GaAs are formed by crystal growth. At this time, since growth material gas easily enters into the narrow second groove 72 by the use of a vapor deposition method, the second groove 72 can be filled up with the guide layer 83 .
[0106] Thereafter, the p-side electrode 95 is formed over the contact layer 81 . The substrate 93 is polished, and then the n-side electrode 94 is formed. Furthermore, a high-reflectance coat and a low-reflectance coat are formed on a resonator plane obtained by cleaving a sample. Thereafter, when the resultant structure is processed to a chip, the semiconductor laser device shown in FIG. 13 is obtained.
[0107] In this embodiment, since the second groove 72 is formed by etching the first current blocking layer 86 from the first groove 71 to the predetermined positions toward the right and left directions, the portions of the second groove 72 extend from the first groove 71 to the positions which are equally distant from the first groove 71 . Accordingly, the widths of the portion of the guide layers 83 filled in the right and left second grooves 72 are equal to each other with a high precision in a self-alignment manner. Thus, the semiconductor laser having the S-ARROW structure emits light in the basic lateral mode stably, and can keep a threshold value of oscillation current in the basic lateral mode low.
[0108] In the embodiments described above, though the layers are grown on then type substrate, a p-type substrate maybe used in the present invention. In this case, it is suitable for the conductivity types of the layers to be reversed to those in the case where the n-type substrate is used.
[0109] The descriptions were made for the embodiment in which the GaAs-series semiconductors are used. In the present invention, the material is not limited to this, and GaN-series, InP-series semiconductors and the like may be employed.
[0110] Moreover, the etching of the semiconductor may be performed by any substance regardless of liquid and vapor, as long as the substance can selectively etch InGaAsP out of other crystals.
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Disclosed is a semiconductor laser having an S-ARROW structure confining a basic lateral mode light between a pair of guide layers extending with a gap therebetween, which increases a precision of a shape of a guide portion, and is capable of stably emitting a light in the basic lateral mode. In the semiconductor laser having an activation layer and a plurality of layers in parallel with the activation layer, a first groove penetrating through at least some of the layers is formed, and a pair of second grooves extending to predetermined positions toward both sides from the first groove are formed in a specified layer among the layers through which the first groove penetrates. Furthermore, a material having a refractive index higher than that of the specified layer is filled up in the second grooves, thus forming two portions having a high refractive index.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the priority of provisional application Serial No. 60/127,691, filed Apr. 5, 1999, and is a continuation of application Ser. No. 09/542,176 filed Apr. 4, 2000, now U.S. Pat. No. 6,336,379. These applications are hereby incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
BACKGROUND OF THE INVENTION
Power is conventionally transmitted from the engine of an automobile or a truck through one of two conventional combinations of power transmission devices. One combination is a mechanically operated friction clutch and a manually shifted countershaft transmission. The other combination is a hydrodynamic drive, typically a torque converter, and an automatically shifted planetary gear transmission.
The clutch and manually shifted countershaft transmission combination includes a friction clutch that is mounted to a flywheel on the vehicle's engine. An input shaft of the countershaft transmission engages and is driven by a driven component of the clutch, conventionally a disk that frictionally engages the flywheel. Countershaft transmissions have meshing gears mounted on parallel shafts. The speed ratio and torque ratio provided by the transmission depends on the ratios of the meshing pairs of gears through which power is transmitted from the input shaft of the transmission to the output shaft. A countershaft transmission is conventionally either a sliding gear transmission or a constant mesh transmission. In a sliding gear transmission, gears are moved along a shaft into or out of engagement with another gear to change the path through which power is transmitted through the transmission and thereby changes the transmission ratios. In a constant mesh transmission, gears are constantly in mesh and positive engagement or friction devices couple the gears to a shaft of the transmission. In either type of transmission, ratios are changed by operation of a shifter mechanism that moves gears in the case of a sliding gear transmission or operates friction or positive engagement devices in the case of a constant mesh transmission.
The hydrodynamic drive and automatically shifted planetary gear transmission combination is driven by a torque converter mounted to a flywheel on an engine. An input shaft of a planetary gear transmission engages and is driven by the torque converter. The planetary gear transmission conventionally has planetary gear assemblies aligned along the axis of the input shaft. Power is transmitted through the planetary gear assemblies by fixing one of the three components of the assembly, the sun gear, the plane gear carrier, or the ring gear, against rotation and applying power to one of the other two components to drive the remaining component. The drive ratio of the transmission is determined by the diameters of the gears of the planetary gear assemblies through which power is transmitted. The path through which power is transmitted through planetary gear assemblies is changed by hydraulically operated devices. A hydraulically operated brake having a band that is mounted to the transmission case and surrounds the ring gear of a planetary gear assembly is conventionally used to secure the ring gear to the transmission case. When the ring gear is secured to the transmission case, power may be transmitted through the sun and planet gear carrier of the planetary gear assembly. Hydraulically operated clutch pack assemblies having adjacent disks that alternately engage a surrounding case and an inner splined shaft are used to selectively couple and uncouple the shaft to the case by applying or removing a hydraulic pressure to the assembly. Hydraulically operated frictional engagement devices, brake bands and clutch packs, provide control of the performance of the transmission. Frictional engagement devices that engage and disengage to change the ratio of planetary gear transmissions can provide a high level of mechanical reliability. Because those devices are actuated by hydraulic pressure, planetary gear transmissions are conventionally shifted automatically by controlled application of hydraulic pressure to frictional engagement devices in the transmission.
These conventional power transmitting combinations have been the bases from which power transmitting combinations and devices have been specifically designed and constructed for use in racing. Racing that primarily requires acceleration, in particular, requires transmissions that are more durable and that must satisfy different requirements than do conventional automotive transmissions. In acceleration racing, such as drag racing, either the maximum available power or the maximum power that can be used to accelerate the car is transmitted through the driveline of the racecar throughout the race. The transmission must provide a high degree of mechanical reliability both in changing gear ratios and in structural reliability. Failure to quickly change gears and failure of a component of the transmission are both causes of lost races.
Cars having the most powerful engines used in drag racing have long required transmissions specifically constructed to transmit the large power created by their engines. Specially constructed planetary gear transmissions that have large and high strength gears and other components have been used in various forms of racing, including drag racing for many years. These transmissions, manufactured by Lenco, Inc. and others, have used high strength planetary gear assemblies with mechanically operated friction engagement devices to provide both reliable changes of transmission ratios and structural reliability.
The most powerful cars for which planetary gear transmissions were specially constructed have conventionally driven these transmissions by clutches that are constructed to provide a significant amount of control of the rate at which the high power generated by the engines of these cars is applied to the driveline of the racecar. The planetary gear transmissions specially constructed for racing and used in the most powerful racecars are coupled to the engine differently than planetary gear transmissions used in conventional automotive applications in that they have been driven by clutches and have conventionally been shifted by mechanically or pneumatically, rather than hydraulically, actuated mechanisms.
While racing planetary gear transmissions provide mechanically reliable gear ratio changes and structural reliability, that reliability comes at the price of requiring power to drive the large and heavy components of the transmission. A significant amount of power is required to drive heavy components of racing planetary gear transmissions. The power required to drive racing planetary gear transmissions is not a significant disadvantage to racecars having the highest power engines. However, the power required to drive these transmissions is a significant disadvantage to racecars that are limited to engines that do not produce more power than the racecar can utilize to increase performance. For such cars, decreasing the power consumed by driving components of the car increases the power that can be used to drive the car and to thereby increase performance.
Countershaft racing transmissions that require less power to drive than racing planetary gear transmissions have recently been developed. In addition to requiring less power to drive than planetary gear racing transmissions, racing countershaft transmissions are lighter than planetary gear racing transmissions. These countershaft racing transmissions are generally constant mesh transmissions having mechanical engagement devices, such as positive jaw clutches, that mechanically couple and uncouple components of the transmission to change the torque drive path through the transmission. These transmissions are sometimes referred to a “clutchless” transmissions because they do not use clutch packs that are used by planetary gear transmissions to change gear ratios. Countershaft transmissions have been used in racecars that have engines that, while producing significant power, do not produce more power than can be used to drive the racecar. A primary objective for equipment used in the driveline of such cars, including transmissions, is to consume as little power as possible and thereby make as much power as possible available to drive the racecar. These transmissions have been developed for and are used by racecars that use clutches to obtain significant control over the application of power to the transmission and to avoid loss of power typically required to drive a torque converter. While these clutches and countershaft transmissions differ considerably in design and construction from clutches and transmissions used in conventional automotive applications, they nevertheless comprise a conventional combination of a friction clutch and countershaft transmission.
Racecars that do not have engines that create very high power have used, and continue to use, torque converter driven modified planetary gear transmissions that were originally constructed for conventional automotive applications. The engines used by many such cars have become sufficiently powerful that modified conventional transmissions fail unacceptably frequently. Recently, devices have been developed to drive a planetary gear racing transmission by a torque converter. Those devices are driven by a torque converter, have a brake mechanism to selectively and reliably withhold and apply power to the transmission, and have been developed specifically for use with racing planetary gear transmissions. One such device is disclosed by U.S. Pat. No. 5,090,528, which is incorporated herein by reference and is assigned to the assignee of the invention that is the subject of this application. Another such device is disclosed by U.S. Pat. No. 5,050,716. These devices, in combination with racing planetary gear transmissions, more nearly resemble the conventional combination of a torque converter and planetary gear transmission than does the combination of a clutch and planetary gear transmission.
The combination of a torque converter drive and a planetary gear racing transmission provides a reliable and durable driveline combination. However, many racecars that use that combination do not use engines that produce the highest power and therefor do not require transmissions having components as large and strong as those of racing planetary gear transmissions. In addition, even racecars for which total weight is not a critical consideration, the weight of planetary gear racing transmissions is a disadvantage because the significant weight of the transmission is at a fixed location in the racecar and thereby limits the amount of weight that can be distributed to increase performance and handling of the racecar. Further, because of the size and durability of their components, racing planetary gear transmissions are significantly expensive components of a racecar.
The need therefor exists for a driveline combination that includes a torque converter drive and a transmission that is lighter and less expensive than combinations that include a racing planetary gear transmission and that is durable and reliable. The need also exists for such a combination further including a driveline brake that can be closely controlled to reliably apply power from the racecar engine to the driveline.
SUMMARY OF THE INVENTION
In accordance with the present invention, the disadvantages of the driveline combination of a torque converter drive and a racing planetary gear transmission have been overcome. A combination is provided in which a torque converter drives a countershaft transmission. A releasable driveline brake may further be included in the combination to selectively withhold and then release power to the driveline of a racecar having the combination of this invention.
More particularly, the preferred combination of the present invention includes a torque converter to driveline coupler. That coupler includes a fluid pump adapted to provide fluid under pressure to a torque converter mounted to a flywheel that is mounted to an engine. The combination also includes a countershaft transmission. The coupler is adapted to engage an input shaft of the transmission and to drive the input shaft of the transmission from the torque converter. The countershaft transmission is preferably a constant mesh transmission.
Additionally, the torque converter to driveline coupler may include a fast-release brake that can prevent the coupler from driving the countershaft transmission when the engine is driving the torque converter.
Accordingly, an object of the present invention is to drive a countershaft transmission by a torque converter.
Another object of the present invention is to provide a combination of power transmission devices that is driven by a torque converter, allows manual changing of transmission ratios, and that consumes less power than previous torque converter drive and racing planetary gear transmission combinations.
Yet another object of the present invention is to provide a combination of power transmission components that is durable enough to withstand racing driveline loads and is less expensive than prior torque converter driven combinations.
These and other objects and advantages of the present invention, as well as details of the preferred embodiment thereof, will be more fully understood from the drawings and the following description.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is an exploded view of a combination of a countershaft transmission and a torque converter to driveline coupler according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As illustrated by FIG. 1, drive combination 10 includes a torque converter to driveline coupler 12 and a countershaft transmission 14 . The torque converter to driveline coupler 12 is driven by a torque converter 20 that is mounted to a flywheel (not shown) that is mounted to a crankshaft of an engine (not shown). The torque converter to driveline coupler 12 has a transmission flange 26 defining a surface at an end of the torque converter to driveline coupler 12 opposite the torque converter. The transmission flange 26 is constructed to mate to a mounting flange of a transmission. The torque converter to driveline coupler 12 is preferably as described by U.S. Pat. No. 5,090,528. The construction and operation of the torque converter to driveline coupler 12 is described in that United States patent, which has been incorporated by reference, and will not again be described.
The countershaft transmission 14 is preferably a transmission manufacture by Long Machine and Tool of Annville, Pa. The countershaft transmission 14 is depicted by FIG. 1 is a two speed transmission including a reverse gear. FIG. 1 includes an exploded view of countershaft transmission 14 that illustrates components essential to characterize the combination of the present invention.
The countershaft transmission 14 includes an upper case 18 and a lower case 22 that are joined together to form an enclosing case for the transmission. The upper case 18 includes a flange 24 and the lower case 22 includes a flange 28 . When upper case 18 and lower case 22 are joined, flanges 24 and 28 are positioned together to mate to transmission flange 26 of torque converter to driveline coupler 12 . As used herein to describe components of the countershaft transmission 14 , forwardly refers to a direction toward the torque converter to driveline coupler 12 , and rearwardly refers to an opposite direction.
Countershaft transmission 14 includes an input shaft 32 . An input bearing 34 is mounted to the input shaft 32 . A seat 35 is formed in a surface of a front wall 37 of the lower case 22 that meets a front surface (not shown) of the upper case 18 that is bounded by the flange 24 . A seat (not shown) in a front wall (not shown) of the upper case 18 is positioned opposite the seat 35 . The seat 35 and the seat in the front wall of the upper case 18 secure the input bearing 34 to the transmission case. The input shaft 32 has an input spline 36 extending towards the torque converter to driveline coupler 12 from the input bearing 34 . The input spline 36 extends forwardly from the countershaft transmission 14 to engage and be driven by the torque converter to driveline coupler 12 . The input spline 36 may engage and be driven by a component of the torque converter to driveline coupler 12 , such as the brake drum identified by U.S. Pat. No. 5,090,528 as 82 . Alternatively, the input shaft 32 may extend through the torque converter to driveline coupler 12 to engage and be driven by the torque converter 20 . In that case, the input shaft also engages and drives components, including a brake, of the torque converter to driveline coupler 12 .
The input shaft 32 has a first gear mounting spline 38 extending rearwardly into the transmission 14 to an inner end 42 . A bore 44 extends into the input shaft 32 from the inner end 42 . A pilot bearing 48 is positioned within the bore 44 . An input drive gear 52 has an internally splined bore 54 that is sized to engage the mounting spline 38 . Input drive gear 52 includes gear section 56 forming a gear for power transmission that is adjacent to bearing 34 . Jaws 58 extend rearwardly from the input drive gear 52 .
Main shaft 62 has a pilot section 64 adjacent to a forward end 66 . Pilot section 64 is sized to be positioned within the pilot bearing 48 aligning the main shaft 62 with the input shaft 32 . A spline 68 extends rearwardly along main shaft 62 from pilot section 64 . The main shaft 62 defines a journal 72 rearwardly adjacent the spline 68 . A bearing 74 is mounted to the main shaft 62 rearwardly adjacent to the journal 72 . An output spline 76 extends along the main shaft 62 rearwardly from the bearing 74 to a rear end 78 of the main shaft 62 . The bearing 74 is received in seat 83 of the rear wall 84 of the upper case 18 and in seat 87 in the rear wall 88 of the lower case 22 . The output spline 76 extends rearwardly from the countershaft transmission case to drive a driveline component, such as a driveshaft (not shown).
A first gear 82 has a bore 85 sized to be positioned around the journal 72 of the main shaft 62 . The first gear 82 includes jaws 86 that extend along the main shaft 62 forwardly from the first gear 82 .
Slider sleeve 92 has an internally splined bore 94 sized to engage the spline 68 of the main shaft 62 . The slider sleeve 92 is thereby rotationally affixed to the main shaft 62 . The slider sleeve 92 has an external spline 96 extending along its length.
A high gear slider 102 has a bore 104 that is internally splined to slidably engage the external spline 96 of the slider sleeve 92 . The high gear slider 102 is thereby rotationally affixed to the slider sleeve 92 and through the slider sleeve 92 to the main shaft 62 . The high gear slider 102 includes jaws 106 that extend forwardly from high gear slider 102 . Jaws 106 are sized and constructed to positively engage the jaws 58 of the input drive gear 52 when the high gear slider 102 is advanced toward input drive gear 52 . A shifter groove 108 extends radially into high gear slider 102 around a circumference of the high gear slider 102 at a location rearward of the jaws 106 . The high gear slider 102 forms reverse gear 111 rearwardly adjacent to the shifter groove 108 .
A first gear slider 112 has a bore 114 that is internally splined to slidably engage the external spline 96 of the slider sleeve 92 . The first gear slider 112 , is thereby rotationally affixed to the slider sleeve 92 and through the slider sleeve 92 to the main shaft 62 . The first gear slider 112 includes jaws 116 that extend rearwardly from the first gear slider 112 . The jaws 116 are sized and constructed to positively engage the jaws 86 of the first gear 82 when the first gear slider 112 is moved rearwardly toward first gear 82 . A shifter groove 118 extends radially into first gear slider 112 around a circumference at a location forward of the jaws 116 .
A countershaft assembly 122 is positioned within the countershaft transmission case parallel to the input shaft 32 and the main shaft 62 . The countershaft assembly 122 has a front journal 124 at the forward extent of the countershaft assembly 122 and a rear journal 126 at the rearward extent of the countershaft assembly 122 . A front bearing 128 receives the front journal 124 and a rear bearing 130 receives the rear journal 126 . The front bearing 128 is received by a seat 132 in a surface of the front wall 37 of the lower case 22 that meets a front surface (not shown) of the upper case 18 that is bounded by the flange 24 . The front bearing 128 is also received in a seat (not shown) in the front wall (not shown) of the upper case 18 that is bounded by the flange 24 . The rear bearing 130 is received in a seat 134 formed in a surface of the rear wall 88 of the lower case 22 that meets the rear wall 84 of the upper case 18 . The rear bearing 130 is also received in a seat 136 formed in a surface of the rear wall 84 of the upper case 18 that meets the rear wall 88 of the lower case 22 .
The countershaft assembly 122 includes an input drive gear 142 that is rearwardly adjacent to the front journal 124 . The input drive gear 142 is positioned to mesh with and be driven by the input gear section 56 . The countershaft assembly 122 also includes a first drive gear 144 positioned forwardly adjacent to the rear journal 126 . The first drive gear 144 is positioned to mesh with and transmit power to the first gear 82 . The counter shaft assembly 122 further includes a reverse drive gear 146 that is positioned intermediate the input drive gear 142 and the first drive gear 144 .
A reverse idler gear 152 is rotatably mounted with an idler shaft 154 that is mounted within upper case 18 and positioned parallel to the main shaft 62 and the countershaft assembly 22 . The reverse idler gear is positioned to mesh with and be driven by the reverse drive gear 146 of the countershaft assembly 122 . The reverse idler gear is positioned rearward of the position of the high gear slider 102 at which the jaws 106 of the high gear slider 102 engage the jaws 58 of the input drive gear 52 .
A high gear fork 162 having arms 164 is positioned within the upper case 18 so that the arms 164 extend into the shifter groove 108 of the high gear slider 102 . A groove 166 extending generally perpendicular to the main shaft 62 is formed in an upper surface 168 of the high gear fork 102 that faces toward the upper case 18 . A high gear shifter arm 172 is positioned adjacent to the upper surface 168 . The shifter arm 172 has a journal 174 that extends into the groove 166 . The shifter arm 172 has a journal 176 that is parallel to the journal 174 and extends oppositely from the journal 174 . The journal 176 is offset a distance from the journal 174 in a direction that is generally perpendicular to the main shaft 62 . The journal 176 extends through a bore 178 in the upper case 18 . The portion of the journal 176 extending through the upper case 18 may be engaged by a shifter (not shown) to rotate the shifter arm 172 about the journal 176 thereby moving the journal 174 , the shifter fork 162 , and the high gear slider 102 along the slider sleeve 92 .
A first gear fork 182 having arms 184 is positioned within the upper case 18 so that the arms 184 extend into the shifter groove 118 of the first gear slider 112 . A groove 186 extending generally perpendicular to the main shaft 62 is formed in an upper surface 188 of the first gear fork 182 that faces toward the upper case 18 . A first gear shifter arm 192 is positioned adjacent to the upper surface 188 . The shifter arm 192 has a journal 194 that extends into the groove 186 . The shifter arm 192 has a journal 196 that is parallel to the journal 194 and extends oppositely from the journal 194 . The journal 196 is offset a distance from the journal 194 in a direction that is generally perpendicular to the main shaft 62 . The journal 196 extends through a bore 198 in the upper case 18 . The portion of the journal 196 extending through the upper case 18 may be engaged by a shifter (not shown) to rotate the shifter arm 192 about the journal 196 thereby moving the journal 194 , the shifter fork 182 , and the first gear slider 112 along the slider sleeve 92 .
Power is applied to the input shaft 32 by the torque converter to drive coupler 12 . The input drive gear 52 is driven by the input shaft 32 . The input drive gear 142 of the countershaft assembly 122 engages and is driven by the input drive gear 52 . The reverse idler gear 152 is driven by the reverse drive gear 146 of the countershaft assembly 122 . The first gear 82 is driven by the first drive gear 144 .
The main shaft 62 is driven only by the high gear slider 102 and the first gear slider 112 . The transmission ratio of the countershaft transmission 14 depends on the positions of the high gear slider 102 and the first gear slider 112 .
When the high gear slider 102 is moved toward the input gear 52 to the position at which the jaws 106 of the high gear slider 102 engage the jaws 58 of the input drive gear 52 , the main shaft is driven by the high gear slider 102 and rotates at the same speed as the input shaft 32 . When the high gear slider is moved rearwardly from the input drive gear 52 to a position at which the reverse gear 111 engages the reverse idler gear 152 , the main shaft 62 is rotated oppositely of the input shaft at a speed that results from the ratios of the input drive gear section 56 and the input drive gear 42 , the reverse drive gear 146 and the reverse gear 111 . When the high gear slider 102 is at a position between the input gear 52 and the reverse idler gear 152 , the high gear slider rotates with the main shaft 62 and does not drive the main shaft 62 .
When the first gear slider 112 is moved forwardly away from the first gear 82 , the first gear 82 freely rotates about the main shaft 62 . When the first gear slider 112 is move rearwardly to a position at which the jaws 116 of the first gear slider engage the jaws 86 of the first gear 82 , the first gear slider 112 rotates with the first gear 82 . The main shaft 62 is driven at a speed that depends on the ratio of the input drive gear section 56 and the input drive gear 142 and the ratio of the first drive gear 144 and the first gear 82 .
As will be appreciated by those of skill in the art, the present invention is not limited to the described embodiment. Modifications and variations of the present invention are possible in light of the teachings of this invention including, for example, use of a countershaft transmission having three or more forward gears. It should be understood that, within the scope of the appended claims, the invention may be practiced other than as described above.
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A drive combination that is disclosed that is particularly suited for use in automobiles constructed to engage in acceleration racing. The drive combination includes a torque converter drive unit that is driven by an engine, and a countershaft transmission that that is driven by the torque converter drive unit. The disclosed drive combination requires less power to drive than known torque converter drive and planetary gear transmission drive combinations used for automobile racing and is lighter than such known drive combinations.
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BACKGROUND OF THE INVENTION
The present invention relates to self-contained bathroom units, and particularly to bathroom units which may be conveniently installed in either new or preexisting building structures, at or above floor level, and above or below sewage drain facilities.
It is well-known to construct bathroom facilities in prefabricated form as a unitary assembly; example may be found in U.S. Pat. No. 3,005,205, wherein there is described a unitary washroom including the exterior washroom walls, plumbing fixtures and storage reservoir assembled as a single prefabricated unit. Further example may be found in U.S. Pat. No. 3,183,525 wherein it is disclosed to construct a toilet system for a fallout shelter; such toilet system including a box-like tank for the temporary storage of sewage. Further example may be found in U.S. Pat. No. 3,582,995, wherein it is disclosed a prefabricated toilet and vanity sump arrangement having a toilet fixture and vanity attached to a rigid box-like structure which forms a shallow reservoir for the storage of sewage and waste water. Such inventions represent structures of various forms for providing bathroom fixtures coupled to a sewage storage reservoir or holding tank in a unitary assembly.
The need for such structures may be as a result of special construction requirements as in remodeling, special use requirements as in fallout shelters, special economic considerations as in prefabricated bathrooms, or considerations of the environment and available external facilities, as in the case of bathrooms positioned below the grade level of existing sewer facilities. Depending upon these and other particular considerations, one or more structural forms may be better adaptable as a solution to particular problems. In meeting the varying requirements of any particular situation it is desirable to provide not only a bathroom unit which may be adapted to the varying requirements, but also one that may be completely functional and aesthetically attractive, and one which may be adapted to the particular decorating and structural limitations at the location where the unit is to be installed.
SUMMARY OF THE INVENTION
The present invention provides a completely adaptable self-contained bathroom unit for many of the applications and special considerations described herein. A generally L-shaped and rigid tank forms the functional and structural base for a self-contained bathroom unit. The tank includes a large reservoir for the storage of sewage and waste liquids, and completely houses a sewage pump and control mechanism for actuating the pump, and plumbing lines for water, sewage collection and disposal, and venting. Further, the tank provides a support base for attachment of other bathroom fixtures as well as providing a collection tank for waste material from these fixtures.
The self-contained bathroom unit described herein may be installed in preexisting structures by merely setting it on floor level, or by recessing it partially into the floor, and in either event the height of all of the bathroom fixtures forming a part of the unit or attached thereto may be readily adjusted to the normal height acceptable for such fixtures. Further, once installed, the self-contained bathroom unit may be easily incorporated into the decorating scheme preferred for the room in which it is installed.
It is therefore a principal object of the present invention to provide a self-contained bathroom unit for installation in new or preexisting structures to accommodate any structural limition which may exist.
It is another object of the present invention to provide a self-contained bathroom unit in which the height of all bathroom fixtures may be made conventional for fixtures of the type disclosed.
It is yet another object of the present invention to provide a self-contained bathroom unit which may be amenable to the decorating scheme for the room in which it is installed.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the invention is described herein, and with reference to the drawings, in which:
FIG. 1 is an isometric view of the invention; and
FIG. 2 is a rear elevation view of the invention; and
FIG. 3 is a view taken along the lines 3--3 of FIG. 1; and
FIG. 4 is a view taken along the lines 4--4 of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIG. 1 there is shown in isometric view the preferred embodiment of the invention. A generally L-shaped tank and enclosure 10 forms the base and support structure for the features described hereinafter. Tank and enclosure 10 is preferably constructed of steel or other rigid material, having a hollow interior. Except for the openings to be described hereinafter for the passage of liquid and sewage wastes, tank 10 is totally enclosed on all sides but one. A cover 12 is sealably fitted over the single open end of the tank 10 for providing access to the interior of tank and enclosure 10. Cover 12 is preferably fitted with a gasket or other sealing arrangement so as to provide an airtight seal against tank and enclosure 10.
A wall-mount toilet fixture comprising a tank 14 and a bowl 16 are bolted against a vertical wall 18 of tank and enclosure 10. Such wall-mount toilet fixtures have inherent advantages over floor-mount toilet fixtures in that they are more sanitary and easier to clean, and the novel construction of the invention enables such fixtures to be conveneiently used.
A basin 20 is bolted to a plate 22 which is supported against the rear side of tank and enclosure 10. Leg 24 supports the outer end of plate 22. FIG. 2 shows a rear view of the invention wherein it can be seen that plate 22 is supported against the rear surface 26 by means of bolts 27 and 28. A third bolt hole 29 is spaced an equal distance from bolt 27, so that plate 22 may also be attached against surface 26 by means of bolts at 27 and 29. Of course, for this latter connection leg 24 must be extended. A support pipe 30 is welded across the rear side of plate 22 to improve rigidity of plate 22.
Basin 20 has a hot water inlet pipe 32 and a cold water inlet pipe 33, both of which may be connected to the structure's water supply. Cold water pipe 33 may be connected via a common cold water tap at 34, to enable a cold water inlet into tank and enclosure 10 for purposes of operating the toilet and other fixtures which may be attached thereto. Basin 20 also has a drain pipe 35 which is connected into tank and enclosure 10. A sewage outlet 36 and a vent outlet 38 is also provided through the side of tank and enclosure 10.
FIG. 3 shows a view taken along the lines 3--3 of FIG. 1, wherein the components inside of tank and enclosure 10 are illustrated. Sewage outlet 36 is connected via a pipe 39 to a sewage pump 40. Sewage pump 40 is actuated by means of an electrical signal over line 42, which is energized by a switch 44. Switch 44 is connected to a rod 46 which extends downwardly through a guide 47 and a float 48. Rod 46 has an upper stop 50 attached thereto, and a lower stop 52 similarly attached. The stops 50 and 52 are positioned on either side of float 48 at a spaced apart distance. When float 48 moves into contact with stop 50 it causes rod 46 to raise up, thereby actuating switch 44 and energizing sewage pump 40. When float 48 moves downwardly into contact with stop 52, it causes rod 46 to move downwardly thereby deactuating switch 44 and deenergizing sewage pump 40. Float 48 has a watertight sleeve passing through its entire internal length, and rod 46 is sized smaller than the sleeve to permit float 48 to freely move upwardly and downwardly along rod 46.
FIG. 4 shows a cross-sectional side view taken along the lines 4--4 of FIG. 3. Toilet bowl 16 is bolted against the vertical wall 18 of tank and enclosure 10 by bolts at 54 and 55. In this manner, vertical wall 18 forms a completely rigid support structure for toilet bowl 16 and tank 14. Pump 40 is positioned along the interior lower floor of tank and enclosure 10, and has a pump intake 41 positioned near the bottom of the tank.
In operation, tank and enclosure 10 may be installed by merely resting it on a floor surface, or it may be recessed into a floor so that the top surface of the lower tank portion is flush with the floor level. In either event, the exterior surface of tank 10 may be covered with carpeting or other floor covering materials, or may be covered with ceramic tile. Alternatively, portions of tank and enclosure 10 may be tiled and other portions may be covered with other floor covering materials. If tank and enclosure 10 is recessed into a floor, plate 22 may be attached against rear surface 26 by bolts placed at locations 27 and 29. Alternatively, if tank and enclosure 10 is merely set atop a floor surface, plate 22 may be attached at locations 27 and 28. In either event, the height of basin 20 may be selected so as to maintain it at a nominal 29-30 inches above floor level. It should be noted that bolts and bolt holes may be provided along either edge of plate 22 so as to permit the attachment of plate 22 on either side of tank and enclosure 10.
After tank and enclosure 10 has been located in a preferred location in a room, the water and sewage connections are made to the appropriate tank connecting points. A vent pipe 38 may be connected to an external vent, or in proper circumstances may be merely vented within the room wherein the unit is located. The electrical connections necessary to operate pump 40 may be obtained by merely plugging a cord into a wall outlet.
In use, the bottom of tank and enclosure 10 gradually becomes filled with liquids and sewage materials until float 48 is raised to a level wherein it contacts stop 50. At this point, stop 50 urges rod 46 upwardly to actuate switch 44 and thereby energize pump 40. Pump 40 operates to pump the collected material from the bottom of the tank to an appropriate sewage disposal site, and at such time as the level of liquid and sewage in the bottom of tank 10 recedes, float 48 engages against stop 52 and causes rod 46 to move downwardly. This downward movement deactuates switch 44 and deenergizes pump 40. The cycle may be repeated at regular intervals as the self-contained bathroom unit is used. The size of tank 10 is preferably large enough to hold forty or more gallons of liquid and other sewage so that material may be collected for a period of time before pump 40 becomes actuated.
The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiment be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than to the foregoing description to indicate the scope of the invention.
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A self-contained bathroom unit including a rigid L-shaped tank enclosure and a toilet attached thereto, the enclosure having a sewage ejector pump located therein and float level detection mechanism for actuating the sewage ejector pump, and attachable basin mounting mechanism, and connections for water inlets, sewage outlets, vents and attachment to other appliances.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains generally to the precision measurement of electromagnetic fields and more specifically to a two-dimensional imager for measuring the electric-field amplitude and phase distribution across an extended spatial region.
2. Description of the Related Art
Radiating antenna apertures require a precise measurement of electro-magnetic fields which are coupled into free space. Precise knowledge of the electromagnetic field distribution in either near or far-field is required for a complete system performance characterization. The measurement provide information on the main beam shape and pointing angle, on sidelobe levels and null depths, on the presence of the deleterious grating lobes, and on element mutual coupling effects.
In the prior art, electronic near-field measurements utilize a field probe mechanically scanned above the radiating aperture. See, Rahmat-Samii et al., The UCLA Bi-polar Planar-Near-Field Antenna-Measurement and Diagnostics Range, IEEE Ant. and Prop. Mag., Vol. 37, No. 6, pp. 16-35, Dec. 1995. The constraints of such a system are imposed by the mechanical movement requirements such as: shielding of the support structure to minimize invasiveness and multiple reflections, mechanical probe position errors that may significantly corrupt the calculated far-field patterns, and phase errors due to the flexing microwave signal cables. Furthermore, such near-field measurement systems require precise probe calibration, are only suitable for a laboratory environment, and may not be usable on high-power systems.
Electronic far-field radar range measurements have many of the same limitations as the near-field measurements. The mechanical positioning and probe calibration errors are mitigated since the measurement is done in the far-field. However, this comes at the expense of significant real-estate demands to satisfy the far-field requirement. Additional errors are introduced by the large separation of the transmitter and the receiver measurement points requiring long distance transmission of high-frequency reference signals. The technique is only suitable for a laboratory environment and is not usable on high-power systems.
Compact range measurements suffer from requirements of the mechanical antenna scans, cannot be used for high-power systems, and require large specialized anechoic chambers.
Optical near-field measurements with probes require precise mechanical movement to mitigate positioning errors, require frequent electric (E)-field calibration, shielding of the surrounding system, and are suitable only for laboratory environments. See, Imaizumi et al., Electric Field Distribution Measurement of Microstrip Antennas and Arrays Using Electro-Optic Sampling, IEEE Trans. on Micro. and Techns., Vol. 43, No. 9, pp. 2402-2407, Sep. 1995.
SUMMARY OF THE INVENTION
The object of this invention is to provide a two-dimensional electric (E)-field imager apparatus capable of making minimally-invasive E-field measurements having high sensitivity, large dynamic range and wide bandwidth without mechanical constraints.
Another objective of this invention is to provide a two-dimensional E-field imager apparatus with long-term stability, and E-field polarization diversity.
These and other objectives are accomplished by a two-dimensional imager for measuring the electric (E)-field amplitude and phase distribution across an extended spatial region for millimeter and microwave electromagnetic waves. The invention uses the basic principle of linear electro-optic effect in a certain class of optical crystals whereby an electric field applied across the crystal shifts the phase of the optical beam propagating through the crystal. The imager consists of a small active area, within a generally passive structure, which measures the E-field amplitude and phase information and impresses this information onto an optical beam. The E-field information is measured by converting the optical signal into an electrical signal and demodulating the E-field information from the electrical signal by processing electronics where the electrical signal is conditioned, stored and the data displayed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the two-dimensional opto-electronic imager system.
FIG. 2 shows the sensing grid of the two-dimensional opto-electronic imager system.
FIG. 3 shows a cross-section of a typical installation of the two-dimensional imaging layer and sensor in a radome.
DESCRIPTION OF THE PREFERRED EMBODIMENT
This invention uses principles of integrated optics to provide a compact, robust and flexible method to implement a two-dimensional electric (E)-field imager with such beneficial properties as high sensitivity, high dynamic range, long-term stability, minimal invasiveness, high bandwidth, and E-field polarization diversity.
The two-dimensional imager 10 for measuring the electric-field amplitude and phase distribution across an extended spatial region for millimeter and microwave electromagnetic waves, as shown in FIG. 1, uses the basic principle of linear electro-optic effect on an optical crystal whereby an electric field applied across the crystal shifts the phase of an optical beam propagating through the crystal.
In the two-dimensional imager 10, an incident optical beam 12 from an optical light source 14 is input into an access network 16. The access network 16 serves to distribute and switch the incident optical beam 12 to a specific optical waveguide 44, or path, used to access a single electric (E)-field sensor 18 on a two-dimensional sensor plane, or grid, 22 located at the end of the optical waveguide 38. The E-field amplitude and phase information is impressed onto a circularly polarized optical beam 35 by a resident electromagnetic field.
The maximum allowed E-field is determined by the nonlinearity in the sensor 18. This nonlinearity is attributed to the sine-shaped response transfer curve, and the E-field at which 1-db compression occurs defines the maximum allowed input as: ##EQU1##
The bandwidth of the sensor 18 is not limited by the material response, but rather by the interaction time between the E-field and the circularly-polarized optical beam 35. The equivalent bandwidth is ##EQU2## where c is the speed of light in a vacuum. After interacting with the electro-optic material comprising the E-field sensor 18, the optical beam 35 is retro-reflected back across the access network 16, where a beamsplitter 34 separates the reflected beam 24 from the incident optical beam 12 and direct it to a photodetector 26 which converts the reflected optical signal 24 to an electrical signal 28. The phase of the reflected optical signal 24 has shifted in a pseudo-random manner by virtue of the time its takes the incident optical light beam 12 and 35 to propagate to the sensor 18 and the reflected optical beam 24 to return. The actual change in phase shift is irrelevant.
The phase shift resident in the reflected optical beam 24 is due to the electric field, E, applied to the sensor 18 which is given by the fomula: ##EQU3## where λ is the optical beam wavelength, n is the optical refractive index of the optical fiber, r is the effective electro-optic coefficient of the optical fiber, and d is the interaction length between E-field and the optical beam.
The preferred embodiment of the two-dimensional imager 10 utilizes, preferably, a single-mode, narrow-linewidth, linearly-polarized laser, a type well known to those skilled in the art, as the optical light source 14. This source provides the necessary stability and low noise for high-dynamic range measurements. The continuous-wave nature of the optical light source 14 allows for real-time measurements. The optical light source 14 may also be a mode-locked, pulsed source for equivalent-time sampling detection.
The access network 16 consists of an acousto-optic beam deflector 17, a type well known to those skilled in the art, to controllably steer the incident optical beam 12 into an appropriate input port 21 of the two-dimensional sensor plane 22; a polarizing beam splitter 34, of any type well known to those skilled in the art, with its transmission axis aligned to pass the linearly-polarized incident light beam 12 through a waveplate 36 of such order as to produce a circularly-polarized optical beam 35 when the linearly-polarized incident light beam 12 passes the waveplate 36; the two-dimensional sensor plane 22; and the same waveplate 36 on the return pass. A portion of the retro-reflected beam 24 is picked off by the polarizing beam splitter 34, with the optical phase shift introduced by the E-field sensor 18 being converted into optical amplitude modulation. This portion of the reflected beam 24 passed through an optical lens 42 that directs the reflected beam into the photodetector 26 which converts the optical amplitude modulated reflected beam 24 into an electrical signal 28 which is applied to the processing electronics 32, such as a computer, which outputs such information as a measurement of electric-field amplitude and phase distribution across an extended spatial region.
The access network 16 may have various configurations that include thermal or electro-optical switches for beam steering, different optical beam distribution methods, and different demodulation schemes. The beam splitter 34 may be a conventional type beam splitter or it may be integrated onto a wafer with the rest of the system. The access network 16 is depicted in the preferred embodiment utilizing an acousto-optic beam deflector 17 as a switch. The deflection of the optical light beam is controlled by a radio frequency (RF) signal, shifting angle as the frequency of the RF signal is changed resulting in a direct mapping from frequency to angle. However, many different types of switching systems may be utilized. For example, an electro-optical deflector may be utilized where the mapping of the output data would be accomplished by plotting a voltage to an angle. A liquid crystal hologram or mechanical manipulation of the beam may also be utilized.
The acousto-optic deflector 17 angular resolution and maximum deflection angle define the largest number of resolvable "spots", the number of resolvable "spots" defines the number on individually-addressable optical waveguides 18 appearing in the two-dimensional sensor plane 22. The largest number of resolvable "spots", N, is given by: ##EQU4## where n is the acousto-optic material refractive index, Λ is the acoustic wavelength, ω 0 is the optical beam diameter, λ is the optical wavelength, and L is the acoustic wave width. With typical material parameters, the number of resolvable spots can exceed 1000.
The waveplate 36 may be a type well known to those skilled in the art, alternatively it may be a plate of birefrigent material or a crystal plate polished to a specified thickness where the crystal direction is oriented in a specific manner.
The light collection lens 42 collects the light from the reflected optical beam 24 coming from many possible directions and focuses it on a single point in the photodetector 26. As an alternative, the lens 42 could be eliminated and a plurality of photodetectors 26 could be utilized.
The photodetector 26 is of a sufficient bandwidth to cover the bandwidth of the E-fields being measured for demodulating the E-field information from the optical carrier. Assuming the photodetector 26 has a frequency-independent responsivity, the photocurrent is composed of a direct-current (dc) component and an E-field related component as:
I.sub.photo =I.sub.dc +I.sub.dc sin(Γ.sub.m) (5)
To establish the lower limit of the sensitivity, an assume that Γ m <<1. Then, the photocurrent is given as: ##EQU5## The system noise level is set by the photodetector 26 shot noise with the RMS noise photocurrent given as:
I.sub.N =√2qBI.sub.dc (7)
where q is the electron charge, and B is the detection electronics bandwidth. (Note: this is not the electro-optic sensor bandwidth.) Thus, if the modulated and the noise photocurrents are equated, the minimum detectable E-field is ##EQU6##
The electrical signal 18 is applied to processing electronics 32 for conditioning the signal, storing and displaying data.
The preferred embodiment of the two-dimensional opto-electronic imager system 10 depicts a single waveguide 38 interfacing with a plurality of sensors 18. The optical source 14 would be a tunable laser 14 and the sensors 18 would contain a selective mirror (not shown) that would only collect a single wavelength. So, as the wavelength of the optical light source 14 is changed, the optical light would couple with different sensors 18, depending upon the wavelength the mirror reflects.
In a second configuration of the two-dimensional sensor plane, or grid, 22 wherein an individual waveguide 38 interfaces with an individual sensor 18, the optical light source 14 would be a single frequency laser. But in both configurations the laser output from the optical light source 14 would be a continuous-wave (CW) laser. The configuration selected by the designer would be an individual preference as to the preferred design of the two-dimensional sensor grid 22.
The second configuration of the two-dimensional sensor plane 22 is shown in FIG. 2. The ends of one optical waveguide bundle 38 containing a plurality of optical fibers, or waveguides, 44 is terminated with an individual sensor element 18 on a thin substrate 53 providing mechanical support. A number of optical waveguides 44 are integrated on a substrate 53 to confine and guide the optical light beams 35 and 24 to and from the individual sensor elements 18. The density of the waveguides 44 equates to 50 waveguides 44 occupying a space of 2 mm with a spacing between them of approximately 40 micrometers. The sensor elements 18 are based on the electro-optic materials previously described. Also, various waveguide 44, substrate 53 and sensor 18 orientations are possible. Further, wavelength-division multiplexing techniques may be employed to reduce the required number of wave guides 44. The preferred embodiment uses sensors 18 incorporating an integrated mirror (not shown) to retro-reflect the circularly polarized incident optical beam 35 through the same optical waveguide 44, comprised of a bundle of optical fibers. For example, the waveguides 44 may be arranged on a 40 μm pitch, with a corresponding packing density of ˜50 waveguides in 2 mm. For high-frequency arrays with small elements, a large number of column sampling points per row can be defined. The waveguides 44 are single-mode and fabricated on the planar surface of the substrate 53 through etching or selective deposition. Typically, the two-dimensional imaging layer is comprised of the waveguides 44, manufactured by PIRI, Inc. of Columbus, Ohio. The sensors 18 may be made of a large class of electro-optic materials, of which a preferable material LiNbO 3 is a member. Such materials must be selectively sensitive to specific polarizations of the E-field and may be used to form the E-field sensor 18. Measurements of E-field polarizations is accomplished by interlaying two-dimensional networks of sensors 18 with their E-field sensitive directions being orthogonal to each other.
An example may be shown by assuming a LiNbO 3 -based sensor (n˜2.2, r˜20 pm/V) with a length of 1 mm being probed by λ=1.33 μm light. A typical high-speed photodetector can handle at most a photocurrent of I dc ˜1 mA. A measurement processing system may have a bandwidth of B=100 Hz to allow for a 10 ms measurement time per sensor. Then
E min ˜0.2 V/m
E max ˜1·10 6 V/m
dynamic range˜130 db
f 3 db ˜80 GHz.
The preferred embodiment of this invention has a potential application as a near-field measurement system for phased array antennas. It is anticipated that the imager is incorporated into a standard radome approximately 1.8 inch thick, or similar cover, as shown in FIG. 3. A two-dimensional grid 22 of electro-optical sensors 18, similar to that shown in FIG. 2, is located above a radiating element 52 of an array 54 separated by an approximately one and one-half inch thick spacer layer of Rohacell® 56, or a similar foam-like material that is electrically transparent. Subsequently, a layer of 0.03 inch fiberglass material 58 between layers of 0.1 inch honeycomb material 62 and 64. The outer layer of honeycomb material 64 is capped with a 0.002 inch fiberglass layer 66 which coated with a 0.005 inch layer of paint 68. The imaging layer 48 is transparent to the electromagnetic emissions from the radiating element 52 and does not attenuate or distort the transmitted signals.
The processing electronics 32 receives the electrical signal 28 from the photodetector 26 that is a replica of the reflected optical signal 24 gathered by the sensors 18. If the measurement of an electrical signal power at any point were desired, then only the power is processed within the processing electronics 32. If both amplitude and phase are desired, more sophisticated processing would be required. The method of processing the information desired within the processing electronics 34 is well known to those skilled in the art.
Therefore, this invention is capable of providing a two-dimensional E-field imager apparatus capable of making minimally-invasive E-field measurements with polarization diversity having high sensitivity, large dynamic range and wide bandwidth without mechanical constraints. Further, it has a long-term stability, and E-field polarization diversity.
This invention not only has applications in electronic warfare and radar systems, where accurate characterization of the operation of phased-array antennas is critical. Complete diagonistic information is provided on the individual radiating module operation in a phased array, on the total array patterns, and on any malfunctions in the array operation. Such information may be used to determine the single element patterns, and the inter-element coupling in a phased array antenna in a phased array antenna. The system will permit in-field antenna repair and recalibration, dynamic self-healing, and dynamic far-field radiation pattern synthesis based on accurate near-field measurements.
The invention also has a broad range of other applications. For example, it may be used as the receiver for an electro-optic imaging system through opaque objects such as security screening of baggage or personnel. The are also medical applications either as part of the electromagnetic imaging system (similar to X-ray or optical tomography) or as a detector in a film-less X-ray system when used with a front-end X-ray to electric-field converter.
Although the invention has been described in relation to an exemplary embodiment thereof, it will be understood by those skilled in the art that still other variations and modifications can be affected in the preferred embodiment without detracting from the scope and spirit of the invention as described in the claims.
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A two-dimensional imager for measuring the electric-field amplitude and phase distribution across an extended spatial region for millimeter and microwave electro-magnetic waves. The imager consists of a small active area within a generally passive structure which measures the electric (E)-field amplitude and phase information and impresses this information onto an optical beam. The E-field information is measured by converting the optical signal into and electrical signal and demodulating the E-field information from the electrical signal by processing electronics where the electrical signal is conditioned, stored and the data displayed.
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FIELD OF THE INVENTION
[0001] The present invention relates to a method for compensating for a voltage offset in a voltage-lambda characteristic curve in relation to a reference voltage-lambda characteristic curve of the two-point lambda sensor, the two-point lambda sensor being situated in the exhaust gas of an internal combustion engine.
[0002] The present invention furthermore relates to a control unit for carrying out the method.
BACKGROUND INFORMATION
[0003] In modern internal combustion engines, lambda sensors for determining the composition of the exhaust gas and for controlling the internal combustion engine are used to optimize the pollutant emission and the exhaust gas aftertreatment. Lambda sensors determine the oxygen content of the exhaust gas, which is used to regulate the air-fuel mixture supplied to the internal combustion engine and therefore the exhaust gas lambda upstream from a catalytic converter. The air and fuel supply of the internal combustion engine are regulated via a lambda control loop in such a way that an optimum composition of the exhaust gas is achieved for the exhaust gas aftertreatment by the catalytic converters provided in the exhaust duct of the internal combustion engine. In gasoline engines, lambda is generally regulated to 1, i.e., a stoichiometric ratio of air to fuel. The pollutant emission of the internal combustion engine may thus be minimized.
[0004] Various forms of lambda sensors are used. In a two-point lambda sensor, which is also referred to as a jump sensor or Nernst sensor, the voltage-lambda characteristic curve has a sudden drop at lambda=1. It therefore essentially permits the differentiation between rich exhaust gas (λ<1) during operation of the internal combustion engine with excess fuel and lean exhaust gas (λ>1) during operation with excess air and enables a regulation of the exhaust gas to a lambda of 1.
[0005] A broadband lambda sensor, also referred to as a continuous or linear lambda sensor, enables the measurement of the lambda value in the exhaust gas in a broad range around lambda=1. Therefore, for example, an internal combustion engine may also be regulated to a lean operation with excess air.
[0006] A continuous lambda regulation upstream from the catalytic converter is also possible by way of a linearization of the sensor characteristic curve using a more cost-effective two-point lambda sensor in a restricted lambda range. The requirement for this purpose is that an unambiguous relationship exists between the sensor voltage of the two-point lambda sensor and lambda. This relationship must exist over the entire service life of the two-point lambda sensor, since otherwise the precision of the regulation is inadequate and impermissibly high emissions may occur. This condition is not met due to manufacturing tolerances and aging effects of the two-point lambda sensor.
[0007] To carry out a continuous lambda regulation using a two-point lambda sensor, determining and compensating for a voltage offset of the existing voltage-lambda characteristic curve in relation to a reference voltage-lambda characteristic curve of the two-point lambda sensor, which is constant over the entire lambda range, by an adjustment of the sensor voltage during overrun fuel cutoff of the internal combustion engine, in which no fuel is supplied to the internal combustion engine, is known. Building thereon, the publication DE 10 2010 027 984 A1 describes a method for operating an exhaust system of an internal combustion engine, in which at least one parameter of the exhaust gas flowing in an exhaust duct is detected by an exhaust sensor. It is provided that during an operating state of the internal combustion engine in which injection and combustion of fuel do not occur, fresh air is supplied to the exhaust duct upstream from the exhaust sensor with the aid of a fresh air supply associated with the exhaust system, and the exhaust sensor is adjusted during this and/or thereafter.
[0008] Sufficiently good compensation of the voltage offset is only possible, however, if it is equally strongly pronounced not only in the event of overrun fuel cutoff with correspondingly oxygenated exhaust gas, but rather in the entire lambda range. This may be the case if the voltage offset has a single cause. However, there are typically multiple superimposed causes for a deviation of the voltage-lambda characteristic curve in relation to the reference voltage-lambda characteristic curve. These may be pronounced at different strengths in various lambda ranges, whereby the voltage offset changes as a function of the exhaust gas lambda. In particular, the causes may be pronounced at different strengths in the lean lambda range and in the rich lambda range. Such a voltage offset dependent on the lambda cannot be sufficiently compensated for by an adjustment in the event of overrun fuel cutoff. A further disadvantage of the method is that modern engine concepts have fewer and fewer overrun phases, which restricts the possibility of such an overrun adjustment.
[0009] Therefore, two-point lambda sensors are usually used upstream from the catalytic converter with a two-point regulation. This has the disadvantage that in operating modes for which a lean or rich air-fuel mixture is necessary, for example, for catalytic converter diagnosis or for component protection, the target lambda may only be set by pilot control, but may not be regulated.
SUMMARY
[0010] It is the object of the present invention to provide a simple and reliable method for compensating for a voltage offset of a two-point lambda sensor during operation of the two-point lambda sensor, to enable continuous lambda regulation using the two-point lambda sensor.
[0011] It is furthermore the object of the present invention to provide a corresponding control unit for carrying out the method.
[0012] The object of the present invention relating to the method is achieved in that for an output voltage of the two-point lambda sensor, the slope or a measure of the slope of the voltage-lambda characteristic curve is determined and is compared to the slope or the measure of the slope of the reference voltage-lambda characteristic curve at the same output voltage, and the voltage offset is determined from a deviation of the determined slope or the measure of the slope of the voltage-lambda characteristic curve from the slope or the measure of the slope of the reference voltage-lambda characteristic curve. The reference voltage-lambda characteristic curve corresponds to the voltage-lambda characteristic curve of an unaged two-point lambda sensor. It defines the setpoint curve of the two-point lambda sensor within the scope of the manufacturing tolerances, for which the lambda regulation of the internal combustion engine is designed. There is an unambiguous relationship between the output voltage of the two-point lambda sensor and the slope (ΔU/Δλ) Ref of the reference voltage-lambda characteristic curve for the reference voltage-lambda characteristic curve. If a voltage offset of the voltage-lambda characteristic curve in relation to the reference voltage-lambda characteristic curve exists in the case of the two-point lambda sensor used, this association between measured slope (ΔU/Δλ) mess and the output voltage no longer applies. A deviation of the slope of the voltage-lambda characteristic curve of the present two-point lambda sensor from the slope of the reference voltage-lambda characteristic curve at a predefined output voltage may be unambiguously associated with a voltage offset.
[0013] The method enables the determination of the voltage offset within the regulating range of the two-point lambda sensor in a lambda range around 1, as predominantly exists during regular operation of the internal combustion engine. The determination of the voltage offset is therefore not linked to operating parameters of the internal combustion engine which result in a particular exhaust gas composition, for example, the overrun phases, which occur very rarely in modern engine concepts. Cost-effective two-point lambda sensors may be used for continuous lambda regulation by the determination and compensation of a voltage offset induced by manufacturing tolerances and aging.
[0014] A simple determination of the slope of the voltage-lambda characteristic curve and therefore a voltage offset may be achieved in that, starting from an output voltage of the two-point lambda sensor, a measured voltage change ΔU mess of the two-point lambda sensor after a predefinable lambda change Δλ is compared to a reference voltage change ΔU Ref of the reference voltage-lambda characteristic curve in the case of an equal lambda change Δλ, and the voltage offset is determined from a deviation of measured voltage change ΔU mess from reference voltage change ΔU Ref . ΔU meas /αλ represents the slope of the voltage-lambda characteristic curve, and ΔU Ref /Δλ represents the slope of the reference voltage-lambda characteristic curve. In the event of equal predefined lambda change Δλ voltage change ΔU is a measure of the slope and therefore may be used directly for the determination of the voltage offset. The lambda range in which the voltage offset is to be determined may be established by the selection of the output voltage of the two-point lambda sensor at which the slope of the voltage-lambda characteristic curve is determined Lambda change Δλ may be achieved by a targeted change of the air-fuel mixture supplied to the internal combustion engine. Since the output voltage of the two-point lambda sensor upstream from the catalytic converter must react very rapidly to lambda changes, the lambda changes must only be applied briefly. The method therefore allows a very rapid determination of the voltage offset.
[0015] According to a preferred embodiment variant of the present invention, it may be provided that the voltage offset is determined for the entire lambda range of the two-point lambda sensor, or values of the voltage offset are determined for various lambda ranges, in particular for a rich lambda range and a lean lambda range. Depending on its cause, the voltage offset may be of different sizes for various lambda ranges. Due to the possibility of determining the voltage offset separately for various lambda ranges, the voltage offset may be compensated for in an adapted way as a function of the lambda range. Many causes of a voltage offset have effects of different strengths in the lean lambda range and in the rich lambda range. This may be adapted to by separate measurement and compensation of the voltage offset in the case of lean exhaust gas mixtures and in the case of rich exhaust gas mixtures.
[0016] According to a further method variant, it may be provided that predefinable lambda change Δλ is set intentionally and/or the determination of the voltage offset is carried out in the case of a system-related lambda change Δλ. Voltage change ΔU in the case of a predefined output voltage of the two-point lambda sensor may be determined by an active, intentionally predefined lambda change Δλ. System-related active lambda changes, for example, as may occur for catalytic converter diagnoses, sensor dynamic diagnoses, or phases using two-point lambda regulation, may be used if necessary to obtain additional measurements for voltage changes, without having to carry out an extra active lambda change for this purpose.
[0017] The compensation of a voltage offset may be improved in that measured voltage change ΔU mess is determined, repeatedly proceeding from an output voltage of the two-point lambda sensor, and/or measured voltage change ΔU mess is determined in the case of positive and negative predefinable lambda changes Δλ, and the determination of the voltage offset is carried out from averaged or filtered measured voltage changes ΔU mess . The repetition of the determination of voltage change ΔU mess enables a plausibility check of the offset compensation. On the one hand, the recognition precision of a voltage offset may be increased; on the other hand, the setpoint lambda is maintained in the chronological average by the measurement of voltage change ΔU mess by multiple immediately successive lambda changes Δλ having opposing directions and subsequent averaging or filtering of the measured values.
[0018] A further improvement in the determination of a voltage offset may be achieved in that measured voltage changes ΔU mess are determined, proceeding from various output voltages of the two-point lambda sensor and the voltage offsets determined therefrom are checked for plausibility by comparison.
[0019] The absolute value and/or the type and/or the duration of predefinable lambda change Δλ may be selected as a function of exhaust gas conditions or operating conditions of the internal combustion engine. Lambda change Δλ may be carried out, for example, by a jump, a ramp, by wobbling, by positive or negative lambda changes Δλ, or by arbitrary combinations thereof. The absolute value and/or the type and/or the duration of predefinable lambda change Δλ may be predefined as a function of the exhaust gas conditions or the operating conditions of the internal combustion engine in such a way that an unambiguous and reliable analysis of the determined slope or determined voltage change ΔU mess may be carried out.
[0020] In systems which permit an overrun adjustment, it may be provided that the determined voltage offset is checked for plausibility by an adjustment of the measured output voltage of the two-point lambda sensor to the reference voltage-lambda characteristic curve in the event of an overrun fuel cutoff of the internal combustion engine. This is advantageous in particular if active lambda change Δλ is itself subject to tolerances.
[0021] In the event of a recognized voltage offset of the two-point lambda sensor, it may be provided that the determined voltage offset of the voltage-lambda characteristic curve is completely or partially compensated for and/or the voltage offset is compensated for as a function of the lambda range of the voltage-lambda characteristic curve. It is frequently not necessary to compensate completely for a voltage offset of the voltage-lambda characteristic curve. It may be sufficient if the voltage offset is only compensated enough that the corrected voltage-lambda characteristic curve corresponds sufficiently well to the reference voltage-lambda characteristic curve. In such cases, it may be sufficient to only determine the voltage offset at a few points of the voltage-lambda characteristic curve, even if the actual characteristic curve shift is caused by multiple superimposed effects.
[0022] According to a particularly preferred embodiment variant of the present invention, it may be provided that causes of the voltage offset are determined from the curve of the voltage offset as a function of lambda, and/or measures for avoiding or reducing the causes of the voltage offset are taken. Thus, for example, it may occur that the voltage-lambda characteristic curve of the two-point lambda sensor is increasingly shifted in the rich lambda range by a fixed absolute value toward lower output voltages, since the sensor is operated excessively hot. In this case, the heating power of the sensor heater may be reduced and the voltage offset may thus at least be reduced.
[0023] The determination of the voltage offset at a predefined output voltage and therefore in a predefined lambda range may be achieved in that a predefined output voltage of the two-point lambda sensor is actively set to determine the voltage offset, or the determination of the voltage offset is carried out when the predefined output voltage is set based on the desired operating conditions of the internal combustion engine. Actively approaching the desired output voltage is reasonable in particular if offset compensation from earlier operating cycles of the internal combustion engine is not yet present. In contrast, if a compensation of the voltage offset has already been carried out in a preceding operating cycle and the data are accordingly present, renewed adjustment may be carried out passively if the desired output voltage is presently provided during the regular operation of the internal combustion engine.
[0024] The object of the present invention relating to the control unit is achieved in that the control unit is designed for the purpose of setting a predefinable lambda change Δλ of the exhaust gas, the control unit has measuring means for determining a voltage change ΔU mess of the two-point lambda sensor as a reaction to defined lambda change Δλ to a reference voltage-lambda characteristic curve of the two-point lambda sensor is stored in the control unit, the control unit has a program sequence for comparing measured voltage change ΔU mess of the two-point lambda sensor after predefinable lambda change Δλ to a reference voltage change ΔU Ref of the reference voltage-lambda characteristic curve in the event of an equal lambda change Δλ and the control unit has a program sequence for determining a voltage offset of the present voltage-lambda characteristic curve of the two-point lambda sensor in relation to the reference voltage-lambda characteristic curve from a deviation of measured voltage change ΔU mess from reference voltage change ΔU Ref . The control unit enables the determination of a voltage offset of a two-point lambda sensor as a function of the present lambda range. Therefore, the voltage offset may be compensated for, whereby a use of the two-point lambda sensor for a continuous lambda regulation is made possible.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 shows voltage-lambda characteristic curves of a two-point lambda sensor having constant voltage offsets in relation to a reference voltage-lambda characteristic curve.
[0026] FIG. 2 shows a third voltage-lambda characteristic curve of a two-point lambda sensor having a voltage offset as a function of lambda in relation to a reference voltage-lambda characteristic curve.
DETAILED DESCRIPTION
[0027] FIG. 1 shows voltage-lambda characteristic curves 10 . 1 , 10 . 3 of a two-point lambda sensor having constant voltage offsets 16 , 17 in relation to a reference voltage-lambda characteristic curve 10 . 2 . Characteristic curves 10 . 1 , 10 . 2 , 10 . 3 are plotted in relation to an axis sensor voltage 20 and in relation to an axis lambda 21 . A first voltage-lambda characteristic curve 10 . 1 is shifted by a negative voltage offset 17 and a second voltage-lambda characteristic curve 10 . 3 is shifted by a positive voltage offset 17 in relation to reference voltage-lambda characteristic curve 10 . 2 . The illustrated lambda range is divided by a marking 12 at lambda=1 into a rich lambda range 11 having lambda<1 and a lean lambda range 13 having lambda>1. Proceeding from a first voltage value 22 of the two-point lambda sensor, in rich lambda range 11 , a first slope triangle 14 . 1 is applied to first voltage-lambda characteristic curve 10 . 1 , a second slope triangle 14 . 2 is applied to reference voltage-lambda characteristic curve 10 . 2 , and a third slope triangle 14 . 3 is applied to second voltage-lambda characteristic curve 10 . 3 . Proceeding from a second voltage value 23 of the two-point lambda sensor, in lean lambda range 13 , a fourth slope triangle 14 . 4 is applied to first voltage-lambda characteristic curve 10 . 1 , a fifth slope triangle 14 . 5 is applied to reference voltage-lambda characteristic curve 10 . 2 , and a sixth slope triangle 14 . 6 is applied to second voltage-lambda characteristic curve 10 . 3 .
[0028] Reference voltage-lambda characteristic curve 10 . 2 corresponds to the curve of the output signal of an intact, unaged two-point lambda sensor in the exhaust duct of an internal combustion engine in the event of a change in the exhaust gas composition. It has its maximum slope at lambda=1. The jump from a high output voltage to a low output voltage takes place in a comparatively small lambda window. For example, due to aging of the two-point lambda sensor, its output voltage may be shifted by a voltage offset 16 , 17 . In the present exemplary embodiment, voltage offset 16 , 17 is equal over the entire lambda range, i.e., both in rich lambda range 11 and in lean lambda range 13 . First voltage-lambda characteristic curve 10 . 1 results in the case of a negative voltage offset 17 , second voltage-lambda characteristic curve 10 . 3 results in the case of a positive voltage offset 16 .
[0029] Slope triangles 14 . 1 , 14 . 2 , 14 . 3 , 14 . 4 , 14 . 5 , 14 . 6 each show a voltage change ΔU, which results in the event of a lambda change Δλ of equal size for all slope triangles 14 . 1 , 14 . 2 , 14 . 3 , 14 . 4 , 14 . 5 , 14 . 6 , proceeding from particular voltage value 22 , 23 of the sensor voltage. Therefore, they represent the slopes of particular voltage-lambda characteristic curve 10 . 1 , 10 . 3 or of reference voltage-lambda characteristic curve 10 . 2 at particular voltage values 22 , 23 . The method according to the present invention utilizes the fact that in the case of reference voltage-lambda characteristic curve 10 . 2 , an unambiguous relationship not only exists between output voltage U of the two-point lambda sensor and lambda λ, but rather also between output voltage U and the slope of characteristic curve ΔU/Δλ. If a voltage offset 16 , 17 exists, the association between the output voltage and the slope of the characteristic curve no longer applies.
[0030] In the case of a positive voltage offset 16 , in the event of a predefined lambda change Δλ and a specific voltage value 22 , 23 of the sensor voltage, a lower voltage change ΔU results in lean lambda range 13 and a higher voltage change results in rich lambda range 11 than in the case of reference voltage-lambda characteristic curve 10 . 2 .
[0031] In the case of a negative voltage offset 17 , in the event of a predefined lambda change Δλ and a specific voltage value 22 , 23 of the sensor voltage, a higher voltage change ΔU results in lean lambda range 13 and a lower voltage change results in rich lambda range 11 than in the case of reference voltage-lambda characteristic curve 10 . 2 .
[0032] From the deviation of measured voltage change ΔU mess from voltage change ΔU Ref expected for reference voltage-lambda characteristic curve 10 . 2 , a measure of the required compensation of voltage offset 16 , 17 is ascertained and a corrected voltage-lambda characteristic curve is calculated, which is congruent with reference voltage-lambda characteristic curve 10 . 2 in the event of complete compensation. It is therefore also possible to obtain an unambiguous relationship between the sensor voltage and lambda in the case of an aged two-point lambda sensor. Therefore, a continuous lambda regulation upstream from the catalytic converter may also be carried out in a restricted lambda range using a two-point lambda sensor, which is cost-effective in comparison to a broadband lambda sensor.
[0033] FIG. 2 shows a third voltage-lambda characteristic curve 10 . 4 of a two-point lambda sensor having a voltage offset dependent on the lambda in relation to reference voltage-lambda characteristic curve 10 . 3 shown in FIG. 1 . In the diagram, the same reference numerals as introduced in FIG. 1 are used. At a third voltage value 24 of the two-point lambda sensor, a seventh slope triangle 15 . 1 is associated with reference voltage-lambda characteristic curve 10 . 2 and an eighth slope triangle 15 . 2 is associated with third voltage-lambda characteristic curve 10 . 4 . At a fourth voltage value 25 of the two-point lambda sensor, a ninth slope triangle 15 . 3 is associated with reference voltage-lambda characteristic curve 10 . 2 and a tenth slope triangle 15 . 4 is associated with third voltage-lambda characteristic curve 10 . 4 .
[0034] As shown in FIG. 1 , slope triangles 15 . 1 , 15 . 2 , 15 . 3 , 15 . 4 describe a voltage change in third voltage-lambda characteristic curve 10 . 4 or reference voltage-lambda characteristic curve 10 . 2 in the event of a predefined lambda change Δλ and therefore the slope of particular characteristic curves 10 . 2 , 10 . 4 .
[0035] In the exemplary embodiment shown, third voltage-lambda characteristic curve 10 . 4 is shifted in the entire lambda range by a fixed absolute value toward higher voltages. This first effect may occur, for example, in the case of two-point lambda sensors having a pumped oxygen reference due to manufacturing tolerances.
[0036] Third voltage-lambda characteristic curve 10 . 4 is additionally shifted in rich lambda range 11 by a fixed absolute value toward lower voltages. This second effect may occur if the two-point lambda sensor is operated excessively hot.
[0037] The first effect is more strongly pronounced than the second effect in rich lambda range 11 , so that in total third voltage-lambda characteristic curve 10 . 4 is also shifted toward higher voltages in rich lambda range 11 , however, less than in lean lambda range 13 .
[0038] In a first method step, the output voltage of the two-point lambda sensor is regulated to fourth voltage value 25 . With a predefined lambda change Δλ which now takes place, a voltage change ΔU mess of the output voltage is determined in accordance with tenth slope triangle 15 . 4 , which is less than voltage change ΔU Ref expected on the basis of reference voltage-lambda characteristic curve 10 . 2 . A compensation of the voltage offset required for the entire lambda range is carried out from this deviation and fourth voltage-lambda characteristic curve 10 . 4 is corrected accordingly.
[0039] In a second method step, the output voltage of the two-point lambda sensor is regulated to third voltage value 24 . With a predefined lambda change Δλ which now takes place, a voltage change ΔU mess of the output voltage results in accordance with eighth slope triangle 15 . 2 , which is greater than voltage change ΔU Ref expected on the basis of reference voltage-lambda characteristic curve 10 . 2 . The remaining compensation of the voltage offset required for rich lambda range 11 is carried out from this deviation for rich lambda range 11 . The voltage-lambda characteristic curve thus obtained is now adapted in the entire lambda range to reference voltage-lambda characteristic curve 10 . 2 .
[0040] Alternatively to the compensation of the voltage offset, the cause of a voltage offset may also be recognized from the curve of the voltage offset as a function of lambda, and may thereupon be ended or at least reduced. In the exemplary embodiment shown in FIG. 2 , for example, the power of an electrical heater of the two-point lambda sensor may be reduced to decrease the second effect.
[0041] An unambiguous determination of an existing voltage offset may be carried out from the comparison of the slope of voltage-lambda characteristic curve 10 . 1 , 10 . 3 , 10 . 4 to the slope of a reference voltage-lambda characteristic curve 10 . 2 at voltage values 22 , 23 , 24 , 25 , which are to be predefined in each case, of the output voltage of the two-point lambda sensor and therefore in predefined lambda ranges. The voltage offset may be ascertained separately for various lambda ranges and corrected accordingly. The ascertained offset compensation may be checked for plausibility by repeating the measurement at the same point or at other points of voltage-lambda characteristic curve 10 . 1 , 10 . 3 , 10 . 4 . The compensation may be improved by averaging or filtering the measuring results.
[0042] In systems which permit an overrun adjustment, the ascertained compensation of the voltage offset may also be checked for plausibility by an overrun adjustment.
[0043] In the case of a use in a motor vehicle, it is advantageous to store the offset compensation which was ascertained in a preceding driving cycle and apply it in the next driving cycle. A corrected characteristic curve is therefore immediately available in the next driving cycle. The offset compensation ascertained in the preceding driving cycle may be used for the plausibility check of offset measurements in the running driving cycle.
[0044] Voltage values 22 , 23 , 24 , 25 may be actively set. This is advantageous if an offset compensation from an earlier driving cycle is not yet present. If an offset compensation is already present, the adjustment may be carried out passively, if a required voltage value 22 , 23 , 24 , 25 is present during the regular operation of the internal combustion engine.
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A method is described for compensating for a voltage offset in a voltage-lambda characteristic curve of a two-point lambda sensor in relation to a reference voltage-lambda characteristic curve of the two-point lambda sensor, the two-point lambda sensor being situated in an exhaust duct of an internal combustion engine. It is provided that the slope of the voltage-lambda characteristic curve is determined for an output voltage of the two-point lambda sensor and is compared to the slope of a reference voltage-lambda characteristic curve at equal output voltage, and the voltage offset is determined from a deviation of the determined slope of the voltage-lambda characteristic curve from the slope of the reference voltage-lambda characteristic curve. Also described is a control unit for carrying out the method. The method and the control unit enable the determination of and compensation for a voltage offset of a two-point lambda sensor caused by aging or manufacturing tolerances.
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FIELD OF THE INVENTION
[0001] This invention relates to a switching power conversion system such as DC-AC (Direct Current-Alternating Current), DC-DC or AC-AC conversion systems or any combination of the above mentioned. More specifically, the invention relates to startup pop elimination in an audio amplifier.
BACKGROUND
[0002] The startup pop elimination system can be a central element of an audio power conversion system.
[0003] Most audio power converters are based on a PWM (Pulse Width Modulation) modulator (digital modulator or analogue modulator) that converts a PCM (Pulse Code Modulated) signal received from a source such as a CD-player, or an analogue signal preceded by a D/A (Digital to Analogue) converter, to for instance pulse-width-modulated signals (digital or analogue PWM modulator).
[0004] The output signal of the modulator is fed to a power stage where it is amplified. A typical power converter includes a switching power conversion stage, a filter and an analogue control system.
[0005] At start-up of the audio power conversion system a general problem is the presence of an audible signal at the output of the system even though there is no input signal applied to the audio power conversion system. The signal at the output at start-up is called pop.
[0006] A contributing source of the start-up pop can be transients when the control system is started from a saturated position.
[0007] When the amplifier starts up the control system will find its correct bias value. It is therefore desired that the control system is correctly biased before startup.
[0008] In WO 2008/072212 the close down pop is minimized by including a parallel power stage with a switch in serial at the output. This implementation is complex since one more power stage is needed.
[0009] U.S. Pat. No. 6,538,590 describes a system using a serial resistor for ramping up. Not for a system with a control loop.
[0010] US 2007/0139103 describes a system for quiet power up and power down of an audio amplifier, however it is only applicable in digital systems.
[0011] There is therefore a need for an improved system and method for minimizing the start-up pop often present in audio power conversion systems.
SUMMARY OF THE INVENTION
[0012] It is therefore an object of the present invention to provide a system for an audio amplifier assembly which alleviates all or at least some of the above-discussed drawbacks of the presently known systems.
[0013] This object is achieved by means of a switching power conversion system for an audio amplifier assembly as defined in the appended claims.
[0014] According to one aspect of the present invention, there is provided a switching power conversion system for startup pop minimization in an audio amplifier assembly, said system comprising:
[0015] a forward path including a compensator, a switching power stage for amplifying an output signal from the compensator, and a demodulation filter for filtering an output signal from the switching power stage and providing an amplified output, said switching power stage including a bootstrap capacitor and a pre-charging circuit for charging the bootstrap capacitor;
[0016] a DC-servo connected between the amplified output and an input of the compensator, thereby enabling reduction of offset voltages in the amplified output;
[0017] a signal path connecting the output of the compensator to the DC-servo; and
[0018] a sequence control unit configured for:
ensuring correct biasing of the compensator and DC-servo at start-up; charging said bootstrap capacitor by controlling said pre-charging circuit in said power stage; and after said correct biasing is ensured and said bootstrap capacitor is charged, starting said switching power stage.
[0022] The present invention is based on the realization that if the output of the compensator is connected to the input of the DC servo (DC-servo) before startup of the power stage, it makes it possible to get the control system out of saturation and correctly biased before startup of the power stage, thereby removing a contributing source to the start-up “pop”. The present invention thus provides for a simplified and a more cost-efficient alternative to previous known systems for minimizing the start-up “pop”.
[0023] Further the inventors have realized that, at startup, the driver stage boot strap capacitor is normally charged by first having a low (sometimes referred to as negative) first pulse with a forced width. When the control system is biased correctly before start up, the first pulse after start-up can be either high (sometimes referred to as positive) or low, without generating an audible “pop”. This is also enabled by the fact that the invention also includes a pre-charge circuit of the boot strap capacitor in the driving stage which makes it possible to start up the power stage with a first high pulse or a first low pulse with small/short width. This is generally not possible in self oscillating systems.
[0024] Further, in one exemplary embodiment said signal path further comprises a switch for connecting or disconnecting the DC servo from the output of the compensator, and wherein said sequence control unit is further configured for:
[0025] closing said switch at start-up, thereby connecting the DC-servo to the output of the compensator and ensuring correct biasing of the compensator and the DC-servo at start-up;
[0026] simultaneously opening said switch and starting said switching power stage.
[0027] This is because that when the amplifier is running normally it is desired that the influence from the input from the compensator output is as little as possible. Thus, by adding a switch to the signal path the output from the compensator to the DC-servo is more or less completely attenuated. In the present context the term “switch” is to be understood as a device having a transfer function that can be either 0 dB (i.e. no attenuation through the device) and substantially −∞dB (i.e. a very high attenuation through the device).
[0028] According to another aspect of the present invention there is provided a method for minimizing start-up pop in an audio amplifier assembly having a switching power conversion system comprising:
[0029] a forward path including a compensator, a switching power stage for amplifying an output signal from the compensator, and a demodulation filter for filtering an output signal from the switching power stage and providing an amplified output, said switching power stage including a bootstrap capacitor and a pre-charging circuit for charging the bootstrap capacitor;
[0030] a DC-servo connected between the amplified output and an input of the compensator, thereby enabling reduction of offset voltages in the amplified output;
[0031] a signal path connecting the output of the compensator to the DC-servo, wherein said method comprises the steps of:
[0032] ensuring correct biasing of the compensator and the DC-servo at start-up, thereby bringing the DC-servo out of saturation;
[0033] charging said bootstrap capacitor;
[0000] starting said switching power stage, after said correct biasing is ensured and said bootstrap capacitor is charged.
[0034] With this aspect of the invention, similar advantages and preferred features are present as in the previously discussed aspect of the invention.
[0035] The invention may advantageously be used for improved start-up in any audio amplifier assembly, in particular high precision DC-AC power conversion systems such as in high efficiency audio amplification.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] For exemplifying purposes, the invention will be described in closer detail in the following with reference to embodiments thereof illustrated in the attached drawings, wherein:
[0037] FIG. 1 a illustrates a block diagram representation of a switching power conversion system in accordance with an embodiment of the present invention.
[0038] FIG. 1 b illustrates a schematic drawing of a DC servo and a switch in accordance with another embodiment of the present invention.
[0039] FIG. 2 illustrates a schematic drawing of a DC servo and switch for a DC servo which is connectable to a compensator in accordance with yet another embodiment of the present invention.
[0040] FIG. 3 a illustrates a block diagram representation of a bootstrap capacitor pre-charge circuit in accordance with yet another embodiment of the present invention.
[0041] FIG. 3 b illustrates a block diagram representation of a bootstrap capacitor pre-charge circuit in accordance with yet another embodiment of the present invention.
[0042] FIG. 4 a illustrates a pre-charge circuit of the positive side of the bootstrap capacitor of a driver in accordance with yet another embodiment of the present invention.
[0043] FIG. 4 b illustrates a sub-block of the pre-charge circuit in FIG. 4 a in accordance with yet another embodiment of the present invention.
[0044] FIG. 5 a illustrates a pre-charge circuit of the negative side of a driver in accordance with yet another embodiment of the present invention.
[0045] FIG. 5 b illustrates a sub-block of the pre-charge circuit in FIG. 5 a in accordance with yet another embodiment of the present invention.
[0046] FIG. 6 illustrates a simulation showing voltage signals at different parts of a power conversion system in accordance with yet another embodiment of the present invention.
DETAILED DESCRIPTION
[0047] In the following detailed description, currently preferred embodiments of the present invention will be described. However, it is to be understood that features of the different embodiments are exchangeable between the embodiments and may be combined in different ways, unless anything else is specifically indicated. Even though in the following description, numerous specific details are set forth to provide a more thorough understanding of the present invention, it will be apparent to one skilled in the art that the present invention may be practiced without these specific details. In other instances, well known constructions or functions are not described in detail, so as not to obscure the present invention.
[0048] FIG. 1 a shows a block diagram 1 of an embodiment of the invention which will be described in greater detail in the following. The system in FIG. 1 comprises a switching power conversion system including a sequence controller 18 controlling the sequence of the upstart, a DC-servo 8 having input from the output 11 of the amplifier and from the output of a switch 6 , the switch 6 being connected to the output of the compensator 5 , feedback filters 12 , 14 , 16 filtering the feedback signals for the control loop, attenuator 3 and clipper 3 that attenuates and clips the input signal 10 , compensator 5 shapes the control loop of the amplifier 1 , comparator 7 , power stage 9 including pre-charge circuit (not shown in FIG. 1 ) for charging the high side boot strap capacitor before startup and a demodulation filter 13 .
[0049] The pop minimization can be done by the following sequence:
[0050] Firstly, the input signal 10 should be as close to zero as possible, this can be done by a clipper 3 and/or an attenuator 3 .
[0051] In step two, for having the amplifier control loop in balance at startup the compensator 5 output is connected to the DC servo 8 input by a switch 6 , this way the compensator 5 and the DC servo 8 can be biased correctly before startup of power stage 9 .
[0052] In step three, the power stage 9 must be capable of starting up with either a negative first pulse or a positive first pulse. To make it possible to start up with a positive first pulse the high side boot strap capacitor must be charged.
[0053] In step four, the switch 6 connecting the output of the compensator 5 to the input of the DC-servo 8 is opened at the same time as the amplifier power stage 9 is started up.
[0054] In step five, the clipper 3 stops clipping and the attenuator 3 stops attenuating.
[0055] Lastly, the amplifier (switching power conversion system) 1 runs normally.
[0056] In general applications, when the power stage 9 is switching normally, the bootstrap capacitor is charged via a diode when the output pulse is low. Therefore, if there is no pre-charging of the bootstrap capacitor being performed, the first pulse needs to be negative. In a case where a self-oscillating control system is being used with a single ended power stage, the switching power conversion system will never start if the first pulse is positive. In other applications, which don't use self-oscillating control systems, the switching power conversion system will always eventually start because it is forced to switch and therefore a negative pulse will follow the (possibly initial) high pulse, and thereby enabling the charging of the bootstrap capacitor.
[0057] However, if the power stage 9 is forced to start-up with a first negative pulse with a certain width, it will often lead to a signal at the output 11 of the amplifier, a “pop”. The width of the pulse depends on the capacitance of the bootstrap capacitor that needs to be charged during this negative period. A high capacitance value is desirable because the bootstrap voltage can then be held for a longer time when there is a long positive pulse, for example because of a clipped high positive signal at the output 11 of the amplifier. In these types of “forced systems” it can be said that the forced negative pulse will cause a considerable “pop”. While in a system according to the present invention the width of the pulse is not forced (due to the pre-charging of the bootstrap capacitor), meaning that the control system is not forced and the first pulse can be a high pulse or a short low pulse and thus the system will not present a “pop” at the output/load.
[0058] In the above-described sequence, steps two and three can be switched or have an overlap. Moreover, the constriction block 3 can be a clipper or an attenuator or both.
[0059] Further, regarding the charge of the boot strap capacitor in step three, it can be done by two current sources one putting current into the + (positive node) of the capacitor and one pulling current out of the − (negative node) of the capacitor, explained in more detail in reference to FIG. 3 a.
[0060] The charge can also be done by a resistor connected to the positive power supply and the + (positive node) of the capacitor and a resistor connected to the negative power supply and to the − (negative node) of the capacitor, explained in more detail in reference to FIG. 3 b.
[0061] Alternatively, the system may comprise an additional switch, so that when the amplifier has started up and is running normally, the DC servo 8 input signal is from the output 11 of the amplifier. There can be a switch in this path so the output signal 11 of the amplifier is not connected to the DC servo 8 in step three when the input of the DC servo 8 is connected to the compensator 5 output. This will ensure that potential noise at the output 11 of the amplifier does not disturb the biasing of the DC-servo 8 in the above-described step two of the sequence.
[0062] The switch 6 from the output of the compensator 5 to the input of the DC-servo 8 can also be removed and the output of the compensator 5 then connected directly to the DC-servo 8 . When both the compensator 5 and the amplifier output 11 are directly connected to the DC-servo 8 without a switch 6 in the path between the compensator 5 output and the DC-servo 8 input there is gain and filter frequency considerations between the compensator 5 output and the amplifier output 11 influence on the DC-servo 8 . When the amplifier is running normally it is desired that the influence from the input from the compensator 5 output is as little as possible. In other words, when the amplifier is running normally, a DC offset between the output of the compensator 5 and the output 11 of the amplifier will only be suppressed by the often larger gain in the amplifier output 11 feedback to the DC-servo 8 , compared to the gain in the compensator 5 output connected to the DC-servo 8 . For example, in some systems the signal swing at the output of the amplifier is about 10 times larger than the output signal swing from the compensator output, so if both of these outputs are connected to the DC-servo with the same resistor values, the feedback from the amplifier output will have about 10 times more gain than the compensator output, which will be acceptable system in some applications. Thus, considerations are taken and depending on the desired application and specifications it is determined if the switch 6 between the compensator 5 and DC-servo 8 can be excluded. In FIG. 1 b a rough schematic drawing of a DC-servo and associated components is shown. The output 112 of the compensator and the input of the DC-servo 108 can be connected with a switch 106 . The switch can be either closed or opened. Thus, in the present context the term “switch” is to be understood as a device having a transfer function that can be either 0 dB (i.e. no attenuation through the device) and substantially −∞0 dB (i.e. a very high attenuation through the device).
[0063] The resistor 101 connected between the output 111 of the amplifier and an input of the DC-servo 108 determines the gain of the DC-servo 108 when the amplifier is running normally. While the resistor 102 connected between the output 112 of the compensator 5 and the switch 106 determines the gain of the DC-servo when the control system is basing during the start-up sequence. Between the output of the DC-servo 108 and an input 110 of the compensator 5 there is a resistor 103 which, together with capacitor 107 , contributes to the gain of the DC-servo in both of the above-described situations.
[0064] In FIG. 2 a detailed schematic of a DC-servo system and a switch in an integrated circuit application is shown. Separate sections 201 - 209 of the schematic have been marked in order to clarify the circuit in the figure and a brief description of each section will be provided in the following. The DC-servo is provided with three switches in section 201 , each having a different resistor value associated with it when connected to the output of the compensator. The decode logic in section 207 is used to select which of the switches and consequently which of the resistor values to be used, depending on the application of the system. The switch and resistor(s) to be used may be selected by an I2C interface (sometimes called inter-integrated circuit, I 2 C). Section 202 contains the operational amplifier used in the DC-servo and the associated (external) capacitor 107 . Section 209 illustrates some ESD (electrostatic discharge) protection components together with a box used to indicate where the output 111 of the amplifier and a resistor ( 101 in FIG. 1 b ) may be connected.
[0065] Further, a switch that is used to short-circuit the DC-servo capacitor, when the system is not in use, is illustrated in section 205 . The aforementioned switch in section 205 is controlled by an input signal 120 . Section 204 comprises two comparators in order to protect from DC at the output of the amplifier when the amplifier is disabled. During this measurement, performed by the comparators in section 204 , the switch in section 206 shorts the output of the DC-servo and the DC-servo OP-amp in section 202 is disabled. The switch in section 206 is controlled by an input signal 123 . The switch Moreover, the above-described configuration (resistor from amplifier output and capacitor at the DC-servo OP amp) creates a low pass filter (RC-filter) for the measurement of the DC level at the output of the amplifier. This is in order to prevent high frequency noise to be detected by the DC-protection in section 204 . Section 203 also contains two comparators in order to protect from DC at the output of the amplifier when the amplifier is running normally. The comparators in 203 are measuring if the DC-servo output is above a certain level. In case the DC-servo is saturated it cannot minimize the DC at the output of the amplifier and it is therefore an indication of DC voltage at the output of the amplifier. Both of the DC-protection circuits render in an output signal 121 , where an optional input/control signal 122 may be applied for masking the saturation when the DC-servo is initializing, i.e. during start-up. The control signals 120 , 122 , 123 may be provided from a control unit (not shown) as known in the art.
[0066] Section 208 provides a voltage references for the comparators in sections 203 and 204 .
[0067] FIG. 3 a shows a block diagram of an exemplary embodiment of a bootstrap pre-charge circuit 301 . This embodiment utilizes current sources 306 , 307 or current generators 306 , 307 for charging the bootstrap capacitor 302 . The current generator 306 is used to provide a first current i 1 to the positive side 305 of the bootstrap capacitor 302 . A second current generator 307 is used to draw a second current i 2 from the negative side 304 of the bootstrap capacitor 302 . Preferably the magnitude of the second current i 2 is equal to the magnitude of the first current i 1 . This is because when the negative side 304 , is connected to a load, such as e.g. a speaker, (not shown) and for the pre-charge current (i 1 ) not to run through the load and cause the undesired “pop”, the current drawing block 307 is connected to the negative side 304 .
[0068] In FIG. 3 b an alternative embodiment of the bootstrap capacitor pre-charge circuit 321 is depicted, in a block diagram representation. Here, the bootstrap capacitor 302 is charged via the resistor 308 which in turn is connected to the positive supply 310 . A connection to the negative supply rail 311 from the negative side 304 is made via a resistor 309 ; in order to draw current similarly to the setup discussed in relation to FIG. 3 a , i.e. to prevent pre-charge current from running through a load, such as e.g. a speaker, (not shown) which is connected to the negative side 304 . Preferably the current through 308 should be equaled by the current through 309 in order to ensure that no pre-charge current flows through the load.
[0069] In FIGS. 4 a -5 b some more detailed examples of a pre-charge circuit and associated sub-blocks are illustrated in a detailed schematic configuration for integrated circuit applications.
[0070] FIG. 4 a shows a detailed schematic of a pre-charge circuit from the positive supply to the positive side of the bootstrap capacitor in an integrated circuit form. Similarly to the procedure in FIG. 2 , the circuit has been divided into sections 401 , 402 which will be further described. Section 401 contains a cascade transistor 403 for handling high voltages and a diode 404 for separation from the bootstrap voltage when the bootstrap capacitor is at a high voltage when the power stage is switching, and a resistor 405 for ESD protection. In section 402 the block for the current mirror for the positive side of the bootstrap capacitor can be seen.
[0071] FIG. 4 b shows a more detailed view of the current mirror block for the positive side of the bootstrap capacitor ( 402 in FIG. 4 a ). Section 411 comprises two transistors 413 , 414 for receiving the input reference current in the current mirror, and section 412 contains the output transistors for supplying the precharge current from the current mirror.
[0072] FIG. 5 a shows a pre-charge circuit from the negative supply to the negative side of the bootstrap circuit. Section 501 in FIG. 5 a , similarly to section 401 in FIG. 4 a , contains a cascade transistor 504 that can handle high voltages and a resistor 503 for ESD protection. The circuit in section 502 includes a reference current for the current mirror for the positive side of the bootstrap capacitor and a current mirror for the negative side of the bootstrap capacitor.
[0073] FIG. 5 b illustrates the “inside” of the current mirror block 502 from FIG. 5 a . Section 511 contains transistors for receiving an input reference current in the current mirror, section 512 contains transistors for generating a reference current for the current mirror for the positive side of the bootstrap capacitor (see FIGS. 4 a -4 b ), and section 513 comprises transistors for the pre-charge of the negative side of the bootstrap capacitor.
[0074] FIG. 6 illustrates a signal simulation of a system in accordance with an embodiment of the invention. The simulation serves to elucidate the inventive start-up sequence and the different signals are illustrated in voltage graphs which will be explained in the following.
[0075] The top window 601 shows the signal from the SCU (Sequence Control Unit) or sequence controller, controlling when the switch for the DC-servo from the compensator is on in the start-up sequence. Window 602 illustrates the signal from the SCU controlling when the bootstrap capacitor is to be pre-charged. Next, one can see the output of the DC-servo in window 603 which indicates that the DC-servo is saturated in the beginning and afterwards biased to a correct bias value after the switch to the DC-servo is closed (window 601 ), i.e. connection is established between the compensator and DC-servo.
[0076] Further, the signal (from the SCU) controlling the activation of the power stage is shown in window 604 and window 605 illustrates the voltage across the bootstrap capacitor in the power stage. Window 606 represents the output of the compensator, where it is indicated that saturation is present in the beginning and that it is biased to a correct bias value after the switch to the DC-servo is closed (window 601 ).
[0077] Lastly, window 607 shows the output signal of the amplifier after it has been filtered through the demodulation filter (low pass filter) and an additional low pass filter for removing switching ripple so that the audio band signal is more visible.
[0078] The invention has now been described with reference to specific embodiments. However, several variations of the switching power conversion system are feasible. For example, the system may be applied to several different applications, such as e.g. in two level or multi level modulation, single ended amplifiers, BTL (Bridge Tied Load) dual supply, etc. Further, the DC-servo used is not limited to first order DC-servos but a higher order DC-servo is equally applicable. Such and other obvious modifications must be considered to be within the scope of the present invention, as it is defined by the appended claims. It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting to the claim. The word “comprising” does not exclude the presence of other elements or steps than those listed in the claim. The word “a” or “an” preceding an element does not exclude the presence of a plurality of such elements.
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A switching power conversion system and a method for start-up pop minimization in an audio amplifier assembly are disclosed. The switching power conversion system comprises a forward path including a compensator, a switching power stage and a demodulation filter. The system further comprises a DC-servo and a pre-charging circuit and a sequence control unit configured for providing a start-up sequence where the compensator and DC-servo are correctly biased and a bootstrap capacitor within the switching power stage is charged before the switching power stage is started. Hereby, it is e.g. possible to minimize the audible start-up pop in audio amplifier assemblies.
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This application is a 371 application of PCT/EP01/10107, filed Aug. 29, 2001.
TECHNICAL FIELD
This invention relates generally to plasma display panels and their construction. Specifically, the invention relates to a plasma screen comprising a front plate which comprises a glass plate on which a dielectric layer and a protective layer are deposited, and comprising a carrier plate coated with a fluorescent layer having a rib structure, which divides the space between front plate and the carrier plate in plasma cells which are filled with a gas, and further comprising one or more electrode arrays on the front plate and the carrier plate for generating silent electrical discharges in the plasma cells.
Plasma screens enable color pictures with high definition, large screen diagonals and have a compact structure. A plasma screen comprises a gas-filled sealed glass cell with grid-like arranged electrodes. By applying an electric voltage, a gas discharge is caused which mainly generates light in the vacuum ultraviolet range. Fluorescence transforms this VUV light into visible light and the front plate of the glass cell emits this visible light to the viewer.
Plasma screens are subdivided into two classes: DC plasma screens and AC plasma screens. With the DC plasma screens the electrodes are in direct contact with the plasma. With AC plasma screens the electrodes are separated from the plasma by a dielectric layer.
In principle, two types of AC plasma screens are distinguished: a matrix arrangement and a co-planar arrangement of the electrode arrays. In the matrix arrangement the gas discharge is ignited and maintained at the point of intersection of two electrodes on the front plate and carrier plate. In the coplanar arrangement the gas discharge between the electrodes on the front plate is maintained and at the point of intersection ignited with an electrode, a so-called address electrode on the carrier plate. The address electrode is located in this case beneath the fluorescent layer. Fluorescent substances which emit different colors are separated by barriers so that only light of the desired color is generated.
For a sufficient picture contrast in daylight it is important for a plasma screen to have a high luminance and the least possible reflection of external light. The parameter of this property is the Luminance Contrast Performance (LCP): LCP = luminance ( L ) reflection ( R )
An enhancement of the contrast and thus an improvement of the LCP value can be achieved, for example, by depositing a so-called black matrix on the barriers or on the areas of the front plate opposite the barriers. Such a black matrix reduces the reflection of ambient light so that the picture contrast is enhanced when the surrounding light is increased.
JP 10-269951 discloses a plasma screen with a black matrix on the front plate which absorbs visible light incident from outside and at the same time reflects light incident from inside. This is achieved in that the side of the black matrix turned away from the viewer is coated with a layer which reflects visible light. This reflecting layer may then be provided directly on the black matrix or parallel therewith with a certain distance.
In either case the black matrix and the reflecting layer are embedded in the dielectric layer, which consists of PbO-containing glass. Under the drastic circumstances during the manufacturing of plasma screens, more particularly high temperatures, this may lead to undesired reactions between the black matrix and/or the reflecting layer with the dielectric layer, which reactions result in discolorations and thus certainly in a reduction of the reflection properties of the reflecting layer.
BACKGROUND AND SUMMARY
Therefore, it is an object of the present invention to provide a plasma display panel or screen which produces a picture with improved contrast.
The object is achieved by a plasma screen comprising a front plate which comprises a glass plate on which a dielectric layer and a protective layer are deposited, comprising a carrier plate coated with a fluorescent layer having a rib structure, which divides the space between front plate and carrier plate in plasma cells which are filled with a gas, and comprising one or more electrode arrays on the front plate and the carrier plate for generating silent electrical discharges in the plasma cells and comprising a structured black matrix which is coated with a reflecting layer between dielectric layer and protective layer on the side turned away from the viewer.
The arrangement of the protective layer and the structured black matrix on which is coated with a reflecting layer is deposited on the side turned away from the viewer, provides that on the dielectric layer and not in the dielectric layer a reaction of the dielectric layer with the reflecting layer is avoided and reactions with the structured black matrix are minimized.
A further advantage of this arrangement is that the reflecting layer on the structured black matrix is closer to the discharge cell. This increases the intensity of the generated light because it is reflected directly and not first passes through the dielectric layer where it may be partially absorbed.
These and other aspects of the invention are apparent from and will be elucidated with reference to the embodiments described hereinafter.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
FIG. 1 shows a generally cross sectional view of a plasma display panel according to the invention, showing structure and function of an individual plasma cell.
DETAILED DESCRIPTION
According to FIG. 1 a plasma cell of an AC plasma screen with a coplanar arrangement of the electrodes is shown and has a front plate 1 and a carrier plate 2 . The front plate 1 comprises a glass plate 3 and on the glass plate 3 is deposited a dielectric layer 4 , preferably of glass containing PbO. On the glass plate 3 are deposited parallel, strip-like discharge electrodes 6 , 7 which are coated with the dielectric layer 4 . The discharge electrodes 6 , 7 can be made of metal or ITO. On the dielectric layer 4 there is a structured black matrix 8 with a reflecting layer 9 which is embedded in the protective layer 5 . The reflecting layer 9 is located on the side of the structured black matrix 8 turned away from the viewer.
The carrier plate 2 is made of glass and parallel, strip-like address electrodes 12 of, for example, Ag, running perpendicularly to the discharge electrodes 6 , 7 are deposited on the carrier plate 2 . These address electrodes are coated with a fluorescent layer 11 which emits light in one of the basic or desired primary colors e.g., red, green or blue. The individual plasma cells are separated by a rib structure 14 with separating ribs preferably of dielectric material.
Usually, a structured black matrix 8 is deposited on a front plate 1 in strips so that it is always positioned between two pairs of discharge electrodes 6 , 7 . The strips of the structured black matrix 8 may partially overlap the discharge electrodes 6 , 7 . The reflecting layer 9 may be as wide as or less wide than the respective strips of the structured black matrix on which it is deposited. The layer thickness of the structured black matrix 8 and of the reflecting layer 9 may be the same or different.
In the plasma cell, that is to say, between the discharge electrodes 6 , 7 of which a respective one alternately works as a cathode or anode, there is a gas, preferably a rare gas mixture of, for example, He, Ne or Kr, which contains Xe as an UV light generating component. After the surface discharge has been ignited, so that charges may flow over a discharge path between the discharge electrodes 6 , 7 in the plasma area 10 , depending on the composition of the gas, a plasma is formed by which radiation 13 is generated in the UV range, more particularly in the VUV range in the plasma area 10 . This radiation 13 excites the fluorescent layer 11 which fluorescent layer emits visible light in one of the three basic colors which light emerges through the front plate 1 and thus represents a lighting pixel on the screen. In the fluorescent layer 11 may be used, for example, as blue-emitting fluorescent substance BaMgAl 10 O 17 :Eu, as a green-emitting fluorescent substance, for example, Zn 2 SiO 4 :Mn and as a red-emitting fluorescent substance, for example (Y,Gd)BO 3 :Eu.
The structured black matrix 8 absorbs light incident from outside, whereas the reflecting layer 9 reflects visible light 15 incident from the inside.
The dielectric layer 4 over the transparent discharge electrodes 6 , 7 is used, for example, in AC plasma screens, for avoiding a direct discharge between the discharge electrodes 6 , 7 consisting of conductive material and thus the formation of a light arc when the discharge is ignited.
For manufacturing a front plate 1 having a structured black matrix 8 which is coated with a reflecting layer 9 on the side turned away from the viewer, first the discharge electrodes 6 , 7 are deposited by the vapor deposition technique and subsequent structuring on a glass plate 3 whose size corresponds to the desired screen size. Subsequently, the dielectric layer 4 is deposited.
For manufacturing a structured black matrix 8 , first a suitable black pigment is dispersed in water with a mixer or mill while dispersing agents are added. As a black pigment may be used, for example, soot, graphite, ferrites such as MnFe 2 O 4 or spinels such as Cu(Cr,Mn) 2 O 4 , Cu(Fe,Cr) 2 O 4 , Cu(Fe,Mn) 2 O 4 , Ni or Mn(Mn,Fe,Cr) 2 O 4 . To the suspension may be added further additives such as, for example, organic binders, solvents or a defoaming agent. For stabilizing the structured black matrix 8 , low-melting glasses or oxides can be added to the suspension.
For manufacturing a reflecting layer 9 , first a suitable white pigment which does not absorb in the visible range of the light is dispersed in water with a mixer or mill while dispersing means are added. As a white pigment may be used, for example, TiO 2 , or Y 2 O 3 . Further additives such as, for example, organic binders, solvents or a defoaming agent may be added to the suspension. For stabilizing the reflecting layer 9 , low-melting glasses or oxides may be added to the suspension.
Depositing and structuring the black matrix 8 , which is coated with a reflecting layer 9 on the side turned away from the viewer, may be effected with different methods.
One possibility is to replace the obtained suspensions with a photosensitive addition, which may contain, for example, polyvinyl alcohol and sodium dichromate. Subsequently, the suspension with the black pigment is first homogeneously deposited on the dielectric layer 4 by means of spraying, immersing or spin coating. The “wet” film is dried, for example, by heating, infrared radiation or microwave radiation. Subsequently, this step is repeated with the suspension with the white pigment.
The obtained black matrix 8 which is coated with a reflecting layer 9 on the side turned away from the viewer is exposed by a mask and the exposed surfaces are cured. By spraying with water the non-exposed areas are rinsed and removed.
Another possibility is represented by the so-called lift-off method. First a photosensitive polymer layer is then deposited on the dielectric layer 4 and, subsequently, exposed through a mask. The exposed areas are cross-linked and the unexposed areas are deposited by a developing step. The black pigment suspension on the remaining polymer sample is removed by means of spraying, immersing or spin coating and this suspension is then dried. After this, the suspension with the white pigment is similarly deposited on the black matrix and dried. A reactive dissolution caused by, for example, a strong acid, makes the cross-linked polymer soluble. By spraying a developer, the polymer together with parts of the covering black matrix 8 and the parts of the covering reflecting layer 9 is removed, whereas the black matrix 8 direct stuck on the dielectric layer 4 together with its covering reflecting layer 9 is not removed.
A further possibility of manufacturing a structured black matrix 8 , which is coated with a reflecting layer 9 on the side turned away from the viewer, is the flexographic printing method. This is a high-pressure method in which only the areas of the dielectric layer 4 to be coated come into contact with the print drum.
Subsequently, a protective layer 5 of MgO is deposited on the reflecting layer 9 and in the spaces between the black matrix/reflecting layer units. The whole front plate 1 is dried, post-processed for two hours at 400° C. and, together with a carrier plate 2 of glass which has a rib structure 14 , conducting address electrodes 12 and a fluorescent layer 11 , as well as a gas, used for forming an AC plasma screen with improved LCP value.
In the following examples of embodiment of the invention will be explained.
Embodiment 1
For manufacturing a front plate 1 with a structured black matrix 8 and a reflecting layer 9 , first 62.5 g of graphite having a mean particle diameter smaller than 1 μm is mixed in a dispersing means solution of 31.25 g of a pigment-affine dispersing means in 530 g of water by mixing it well. The suspension obtained was mixed with 10 g of a 5% watery solution of a non-ionogenic defoaming agent and ground with glass spheres in a ball mill. In this way a stable, fine-particle suspension was obtained which was filtered by a wire gauze. The suspension was mixed with a 10% polyvinyl alcohol solution and, in addition, sodium dichromate was added to the suspension. (The polyvinyl-alcohol-to-sodium dichromate proportion was 10:1).
Furthermore, an analogous suspension of TiO 2 with a mean particle diameter of 300 nm was made which was subsequently mixed with a 10% polyvinyl alcohol solution and with sodium-dichromate (polyvinyl alcohol/sodium dichromate=10:1).
The suspension of the black pigment was deposited on the dielectric layer 4 of a front plate 1 by means of spin coating, which front plate 1 comprised a glass plate 3 , a dielectric layer 4 and discharge electrodes 6 , 7 . The dielectric layer 4 comprised PbO-containing glass and the two discharge electrodes 6 , 7 were made of ITO. The distance between the two discharge electrodes was 60 μm in a screen line, the distance between two screen lines was 500 μm. After drying the obtained black matrix which is to be covered with a reflecting layer on the side turned away from the viewer, the suspension of the white pigment was deposited on the black matrix 8 by means of spin coating.
The black matrix 8 with a reflecting layer 9 was radiated with UV light through a mask and thus the polymer on the radiated positions was cross-linked. Subsequently, by spraying with warm water the non-cross-linked areas of the black matrix 8 and of the reflecting layer 9 were rinsed. The width of a row of the structured black matrix 8 was 400 μm.
The whole front plate 1 was dried and post-processed at 450° C. for two hours. Subsequently, the protective layer 5 of MgO was deposited.
The layer thickness of the dielectric layer 4 was 30 μm, the layer thickness of the black matrix 8 was 3 μm and the layer thickness of the reflecting layer 9 was 10 μm.
The obtained front plate 1 together with a carrier plate 2 of glass, which has a rib structure 14 , address electrodes 12 of Ag and a fluorescent layer 11 and also with a xenon-containing gas mixture was used for manufacturing a plasma screen whose LCP value was increased by 15%.
Embodiment 2
For manufacturing a front plate 1 with a structured black matrix 8 which is coated with a reflecting layer 9 on the side turned away from the viewer, first 62.5 g Cu(Cr,Mn) 2 O 4 having a mean particle diameter smaller than 1 μm, is mixed with the five-fold mixture of low-temperature melting glass. After water and an anorganic binding agent were added, the black matrix 8 was printed on the dielectric layer 4 of a front plate 1 by means of flexoprinting, which front plate 1 comprised a glass plate 3 , a dielectric layer 4 and discharge electrodes 6 , 7 . The structured black matrix 8 was dried at 150° C. Subsequently, the reflecting layer 9 was similarly printed by means of flexoprinting on the structured black matrix 8 . For this purpose, 62.5 g of Y 2 O 3 having a mean particle diameter of 500 nm was mixed with the five-fold mixture of low-temperature melting glass and then water and a binding agent were added to this mixture.
The distance between the two discharge electrodes 6 and 7 in a screen line was 60 μm, the distance between two screen lines was 500 μm and the width of one row of the structured black matrix 8 which is coated with a reflecting layer 9 was 600 μm.
The whole front plate 1 was dried and post-processed at 450° C. for two hours. Subsequently, the protective layer 5 of MgO was deposited.
The layer thickness of the dielectric layer 4 was 30 μm, the layer thickness of the structured black matrix 8 was 5 μm and the layer thickness of the reflecting layer 9 was 20 μm.
The obtained front plate 1 , together with a carrier plate 2 of glass, which has a rib structure 14 , address electrodes 12 of Ag and a fluorescent layer 11 and also with a xenon-containing gas mixture was used for manufacturing a plasma screen.
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A plasma display panel having a structured black matrix ( 8 ) which is coated with a reflecting layer ( 9 ) on the side turned away from the viewer. Visible light incident from outside is absorbed by the black matrix ( 8 ) and light incident from inside is reflected by the reflecting layer ( 9 ). This enhances the LCP value of the whole plasma screen. A protective layer ( 5 ) such as MgO is deposited on the black matrix and reflecting layer and so formed over the black matrix and said reflecting layer so as to reduce undesired reactions of the black matrix and the reflecting layer with the dielectric layer, such as during high temperature conditions during manufacture.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is related to Japanese Patent Application No. 2006-189344, filed on Jul. 10, 2006, the content of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Technical Field of the Invention
The present invention relates to power transfer devices for transferring power between two component parts and, more particularly, to a rotational power transfer device, having first and second rotary members operative to interrupt a transfer of a rotational power when either the first and second rotary members is exerted with the rotational power exceeding a given value, and related manufacturing method.
2. Description of the Related Art
In the related art, an attempt has heretofore been made to provide rotational power transfer devices that are operative to interrupt a transfer of a rotational power in excess. One example of these devices is disclosed in, for instance, Japanese Patent Application Publication No. 5-171168. In this related art, the rotational power transfer device is employed in a starter and includes a clutch gear and a barrel. A lubricating layer, composed of a manganese phosphate film and a lubricating film, is formed on an inner periphery of the clutch gear and an outer periphery of the barrel. The lubricating film is composed of a mixture of molybdenum disulfide and resin. The clutch gear is press fitted to the barrel with the inner periphery held in face-to-face relation to the outer periphery of the barrel. In addition, the clutch gear and the barrel are so set such that as a rotational power is exerted between the clutch gear and the barrel at a value beyond a given value, a slippage occurs between these component parts.
With the starter employing such a power transfer device, a rotational power of an armature is transferred to the clutch gear via a drive gear and an idling gear. The drive gear, the idling gear and the clutch gear are coated with lubricating oil such as ester family oil or α-olefin family oil with a low frictional coefficient and high permeability with a view to preventing the occurrence of a wear. Lubricating oil scatters to surrounding areas with the rotation of the gears. It has been turned out that as scattered oil adheres onto the barrel and its vicinity and permeates to between the clutch gear and the barrel, a cleavage fracture takes place in molybdenum disulfide that form the lubricating film with a resultant increase in the frictional coefficient. As the frictional coefficient increases, there occurs an increase in the rotational power at which the slippage is caused to occur between the clutch gear and the barrel. Under such a situation, the clutch gear and the barrel become hard to absorb the rotational power in excess resulting from an impact occurring when the pinion is brought into meshing engagement with a ring gear of an internal combustion engine. This results in a fear of causing the gears and the armature to rupture.
SUMMARY OF THE INVENTION
The present invention has been completed with a view to addressing the above issues and has an object to provide a rotational power transfer device, operative such that even when oil such as lubricating oil with low frictional coefficient and high permeability intrudes to between associated component parts, the associated component parts suppresses an increase in the rotational power causing a slippage for thereby stably absorbing the rotational power in excess, and related manufacturing method.
The present inventor has undertaken committed research and development work through a trial and error process to address the above issues. Upon such research and development work, it is turned out that coating grease, composed of a mixture of oil with a higher frictional coefficient than that of lubricating oil and molybdenum disulfide, on either one of the inner periphery of the first rotary member and the outer periphery of the second rotary member enables the suppression of an increase in the rotational power at which a slippage occurs. Thus, the present invention has been completed with successful results.
To achieve the above object, a first aspect of the present invention provides a rotational power transfer device comprising a first rotary member having an inner cylindrical periphery, and a second rotary member, having an outer cylindrical periphery and press fitted to the first rotary member to allow the outer cylindrical periphery to be placed in face-to-face relation to the inner cylindrical periphery of the first rotary member, which is operative such that either the first rotary member or the second rotary member is imparted with a rotational power greater than a given value, a slippage occurs between the first rotary member and the second rotary member for interrupting a transfer of the rotational power. Grease composed of a mixture of oil with a higher frictional coefficient than that of lubricating oil and molybdenum disulfide is coated on at least one of the first rotary member and the second rotary member.
With grease, composed of the mixture of oil with the higher frictional coefficient than that of lubricating oil and molybdenum disulfide, which is coated on at least one of the first rotary member and the second rotary member, grease is associated with the solid lubricating layer to suppress a leakage of oil with a higher frictional coefficient than that of lubricating oil and can intervene between the first and second rotary members. The presence of grease containing molybdenum disulfide prevents impurities, causing a degraded variation in frictional coefficient, from intruding an intervening area between the first and second rotary members.
With the rotational power transfer device of the present embodiment, the first rotary member may preferably include a gear having an outer cylindrical periphery formed with gear teeth on which the lubricating oil is coated.
With such a structure, the rotational power can be reliably transferred from the first rotary member to the second rotary member via the gear.
With the rotational power transfer device of the present embodiment, the lubricating oil may preferably include at least one of ester family oil or α-olefin family oil.
With such a structure, the lubricating oil can prevent the gear from wearing.
With the rotational power transfer device of the present embodiment, the grease may preferably contain molybdenum disulfide in a proportion ranging from 50 to 70%.
With such a structure, such grease containing molybdenum disulfide in an optimum range prevents a leakage of oil with a higher frictional coefficient than that of lubricating oil, while providing improvement in workability of applying grease.
If grease contains molybdenum disulfide in a proportion less than 50%, a leakage of oil with a higher frictional coefficient than that of lubricating oil is liable to occur. Thus, the rotational power transfer device becomes hard to ensure reliable operating characteristics for a prolonged period of time.
On the contrary, if the concentration of molybdenum disulfide is greater than 70%, grease has increased viscosity, causing degraded workability to take place in coating grease. Therefore, grease is selected to contain molybdenum disulfide in a proportion ranging from 50 to 70% and, more preferably, in a proportion ranging from 55 to 65% in consideration of such issues. This precludes a leakage of oil with a higher frictional coefficient than that of lubricating oil, thereby improving the workability for grease to be coated.
With the rotational power transfer device of the present embodiment, at least one of the first rotary member and the second rotary member may further preferably include a lubricating layer composed of a chemical film, formed by chemical treatment, and molybdenum disulfide.
With such a structure, the presence of the lubricating layer enables the suppression of a further increase in the rotational power at which the slippage occurs.
A second aspect of the present invention provides a starter incorporating the rotational power transfer device according to claim 1 . The starter comprises a motor, an output shaft rotatably driven with the motor, and a pinion carried on the shaft to be rotatable therewith. The first and second rotary members are disposed between the motor and the pinion for transferring the rotational power of the motor to the pinion and operative such that a rotational power, accompanied by an impact occurring when the pinion is brought into meshing engagement with a ring gear, exceeds a given value, a transfer of the rotational power from the pinion to the motor is interrupted.
With such a structure, even if lubricating oil intrudes an area between the first and second rotary members, no increases occurs in the rotational power at which the slippage occurs. In addition, the first and second rotary members can stably absorb the rotational power in excess resulting from an impact shock when the pinion is brought into meshing engagement with the ring gear. This allows the starter to have improved reliability in operation.
A third aspect of the present invention provides a rotational power transfer device comprising a rotary tubular member having an inner cylindrical periphery coated with a solid lubricating layer composed of a chemical film applied to the inner cylindrical periphery and a layer of molybdenum disulfide applied to the chemical film, and a rotary shaft member, having an outer cylindrical periphery and press fitted to the rotary tubular member to allow the outer cylindrical periphery to be placed in face-to-face relation to the inner cylindrical periphery of the rotary tubular member, which is operative such that either the first rotary member or the second rotary member is imparted with a rotational power greater than a given value, a slippage occurs between the rotary tubular member and the rotary shaft member for interrupting a transfer of the rotational power therebetween. A layer of grease is coated on at least one of a surface of the solid lubricating layer and the outer cylindrical periphery of the rotary shaft member and composed of a mixture of oil with a higher frictional coefficient than that of lubricating oil and molybdenum disulfide.
With such a structure of the rotational power transfer device, at least one of the first rotary member and the second rotary member is applied with grease composed of the mixture of oil with a higher frictional coefficient than that of lubricating oil and molybdenum disulfide. Grease is associated with the solid lubricating layer to suppress a leakage of oil with a higher frictional coefficient than that of lubricating oil and can intervene between the rotary tubular member and the rotary shaft member. The presence of grease containing molybdenum disulfide prevents impurities, causing a degraded variation in frictional coefficient, from intruding an intervening area between the rotary tubular member and the rotary shaft member.
A fourth aspect of the present invention provides a method of manufacturing a rotational power transfer device, the method comprising preparing a first rotary member having an inner cylindrical periphery, preparing a solid lubricating layer on the inner cylindrical periphery of the first rotary member by forming a chemical film thereon and applying a powder of molybdenum disulfide on a surface of the chemical film, preparing a second rotary member, conducting a heat treatment on the second rotary member, grinding a surface of an outer cylindrical periphery of the second rotary member, preparing a grease composed of a mixture of a lubricating oil with a high frictional coefficient and a powder of molybdenum disulfide, coating the grease on at least one of the first and second rotary members, and press fitting the first rotary member onto the second rotary member to allow the outer cylindrical periphery of the second rotary member to be placed in face-to-face relation to the inner cylindrical periphery of the first rotary member with the grease intervening between the solid lubricating layer and the outer cylindrical periphery of the second rotary member. The rotational power transfer device is operative such that either the first rotary member or the second rotary member is imparted with a rotational power greater than a given value, a slippage occurs between the first rotary member and the second rotary member for interrupting a transfer of the rotational power therebetween.
With such a method of manufacturing a rotational power transfer device, a layer of grease containing a mixture of oil having a high frictional coefficient and molybdenum disulfide intervenes between the solid lubricating layer of the first rotary member and the outer circumferential periphery of the second rotary member. This allows the rotational power transfer device to have increased reliability in operation for prolonged period of time.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially cutaway cross sectional view of a starter employing a rotational power transfer device of an embodiment according to the present invention.
FIG. 2 is a partially cutaway cross sectional view of the rotational power transfer device of the embodiment shown in FIG. 1 in an enlarged scale.
FIG. 3 is a fragmentary cross sectional view showing a clutch gear and a barrel, to which the rotational power transfer device of the embodiment is applied, in an enlarged scale.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Now, a rotational power transfer device of an embodiment according to the present invention will be described below in detail with reference to the accompanying drawings. However, the present invention is construed not to be limited to such an embodiment described below and technical concepts of the present invention may be implemented in combination with other known technologies or the other technology having functions equivalent to such known technologies.
Now, a rotational power transfer device of an embodiment according to the present invention will be described below in detail with reference to FIGS. 1 to 3 of the accompanying drawings.
With the present embodiment, the rotational power transfer device will be described with reference to an exemplary case as applied to a starter for startup of an engine.
First, reference is made to FIGS. 1 to 3 for describing a structure of the present embodiment. Here, FIG. 1 is a partially cross sectional view showing the starter incorporating the rotational power transfer device of the present embodiment. FIG. 2 is an enlarged cross sectional view showing a local area in the vicinity of a shaft. FIG. 3 is a partially enlarged view showing a clutch gear and a barrel implementing a concept of the present invention.
As shown in FIG. 1 , the starter 1 includes a motor 2 , an idling gear 3 , a clutch gear 4 (first rotary member) playing a role as a tubular member, a barrel 5 (second rotary member) playing a role as a shaft member, a clutch 6 , a shaft 7 , a pinion 8 , and an electromagnetic switch 9 .
The motor 2 and the electromagnetic switch 9 are fixedly mounted onto a center case 10 in areas rearward of a housing 11 . In addition, the idling gear 3 , the clutch gear 4 , the barrel 5 , the clutch 6 , the shaft 7 and the pinion 8 are located in an intermediate space between the center case 10 and the housing 11 .
Hereunder, various components elements of the starter 1 will be described below further in detail. The motor 2 includes a direct current motor that generates a rotational power for starting up the engine. The motor 2 has an output shaft having its front end carrying thereon a drive gear 2 a . The drive gear 2 a has gear teeth to which, for instance, ester family oil or α-olefin family oil with a low frictional coefficient and high permeability is applied as lubricating oil for avoiding the occurrence of wear.
The idling gear 3 included a cylindrical gear made of metal and is held in meshing engagement with the drive gear 2 a of the motor 2 for transferring the rotational power from the motor 2 to the clutch gear 4 at a reduced speed. The idling gear 3 is rotatably supported on an idling pin 3 a , fixedly mounted to between the center case 10 and the housing 11 , by means of rollers 3 b . The idling gear 3 has gear teeth to which, for instance, ester family oil or α-olefin family oil with a low frictional coefficient and high permeability is applied as lubricating oil for minimizing the occurrence of wear.
As shown in FIGS. 1 and 2 , the clutch gear 4 is composed of a cylindrical gear made of metal and held in meshing engagement with the idling gear 3 for transferring the rotational power from the idling gear 3 to the barrel 5 at a reduced speed.
As shown in FIG. 3 , the clutch gear 4 has an inner circumferential wall 4 d formed with a solid lubricating layer 4 c (lubricating layer) composed of a chemical film 4 a and a layer of molybdenum disulfide 4 b.
In forming the solid lubricating layer 4 c , the chemical film 4 a is formed on the inner circumferential wall 4 a of the clutch gear 4 by bonderizing treatments. Thereafter, powder of molybdenum disulfide 4 b is coated on a surface of the chemical film 4 a , upon which tumbling treatments are carried out. With such treatments, the solid lubricating layer 4 c is formed on the inner circumferential periphery 4 a of the clutch gear 4 .
As shown in FIGS. 1 and 2 , the gear teeth of the clutch gear 4 is coated with ester family oil or α-olefin family oil as lubricating oil in the same manner as that applied to the drive gear 2 a and the idling gear 3 .
The barrel 5 includes a substantially cylindrical member, made of metal, for transferring the rotational power from the clutch gear 4 to the clutch 6 . As shown in FIG. 3 , the barrel 5 has a cylindrical outer peripheral wall coated with a layer of grease 5 a composed of a mixture including oil with a higher frictional coefficient than that of lubricating oil, coated on the gear teeth of the drive gear 2 a , the idling gear 3 and the clutch gear 4 , and molybdenum disulfide. Here, grease 5 a contains molybdenum disulfide in a proportion ranging from 50 to 70%.
The barrel 5 is subjected to heat treatment and, subsequently, an outer periphery of the barrel 5 is grounded and applied with grease 5 a . The clutch gear 4 is coupled to the barrel 5 by shrink fitting under a state where an inner surface of the solid lubricating layer 4 c is held in face-to-face relation to the outer periphery of the barrel 5 coated with grease 5 a . Here, the shrink fitting is conducted with a press-fitting margin determined for the clutch gear 4 and the barrel 5 such that if a rotational power beyond a given value is exerted to either the clutch gear 4 or the barrel 5 , a slippage occurs between the clutch gear 4 and the barrel 5 to interrupt the rotational power to be transferred therebetween.
As shown in FIGS. 1 and 2 , the barrel 5 is fixedly secured onto an outer 6 a , which will be described later, via a pin 5 b and rotatably supported on an inner 6 d , which will be described later, via a bearing 5 c.
Thus, the barrel 5 plays a role as a device that transfers the rotational powers of the clutch 6 and the barrel 5 to the shaft 7 while when a rotational speed of the shaft 7 exceeds a rotational speed of the barrel 5 , the barrel 5 runs idle to interrupt the rotational power being transferred. The clutch 6 includes the outer 6 a , rollers 6 b , springs 6 c and the inner 6 d . The clutch outer 6 a is fixedly secured to the barrel 5 . The rotational power of the barrel 5 fixed to the outer 6 a is transferred to the inner 6 b that is pressed with the spring 6 c . The inner 6 d has an inner peripheral wall formed with a helical spline 6 e . The inner 6 d is rotatably supported with the center case 10 and the housing 11 via bearings 6 f , 6 g.
The shaft 7 is a cylindrical member, made of metal, which is operative such that upon pushing movement of the electromagnet switch 9 , the shaft 7 moves in an axial direction while transferring the rotational power from the inner 6 d to the pinion 8 . The shaft 7 has a front end portion whose outer periphery is formed with a straight spline 7 a and a rear end portion formed with a helical spline 7 b . Under a status where the helical spline 7 b held in coupling engagement with the helical spline 6 e of the inner 6 d , the shaft 7 is supported to be internally movable back and forth in an axial direction. In addition, the inner 6 d has an inner bore 6 f accommodating therein a return spring 7 c that is held in contact with an annular shoulder portion 7 d of the shaft 7 to press the shaft 7 rearward with respect to the inner 6 d.
The pinion 8 is a substantially cylindrical gear in meshing engagement with a ring gear 12 of an internal combustion engine (not shown) to transfer the rotational power from the shaft 7 to the engine for cranking up operation thereof. The pinion 8 is internally formed with a straight spline 8 a . The pinion 8 is slidably supported on the front end portion of the shaft 7 under a condition where the straight spline 8 a is held in coupling engagement with the straight spline 7 a of the shaft 7 .
Now, the operation of the starter 1 will be described below with reference to FIGS. 1 and 3 .
In the starter 1 shown in FIG. 1 , as an ignition switch (not shown) is turned on, the electromagnetic switch 9 is energized. In this moment, the electromagnetic switch 9 generates an electromagnetic force causing a plunger 9 a to protrude forward. With such protruding movement of the plunger 9 a , contacts of the electromagnetic switch 9 are closed, thereby supplying the motor 2 with D.C. electric power. Thus, the motor 2 is turned on to rotate generating a rotational power to start up the engine. The rotational power of the motor 2 is transferred from the drive gear 2 a to the clutch 6 through the idling gear 3 , the clutch gear 4 and the barrel 5 . In addition, the rotational power is further transferred from the shaft 7 to the pinion 8 , which is consequently rotatably driven. When this takes place, the forward movement of the plunger 9 a causes the shaft 7 to move forward.
During such forward movement of the shaft 7 , the pinion 8 is brought into meshing engagement with the ring gear 12 of the engine for cranking up the same. During a moment in which the pinion 8 in rotation is brought into meshing engagement with the ring gear 12 remaining stationary, an impact force instantaneously acts on the pinion 8 during meshing engagement between the pinion 8 and the ring gear 12 . The impact force acts as a reverse rotational power that is transferred from the pinion 8 to the barrel 5 via the shaft 7 and the clutch 6 . If such a rotational power exceeds a given value, a slippage occurs between the clutch gear 4 and the barrel 5 . Therefore, no probability occurs for the rotational power, derived from such an impact force, to be transferred in excess to the clutch gear 4 , the idling gear 3 , the drive gear 2 a and the motor 2 .
Further, as the pinion 8 drives the ring gear 12 upon which the rotational speed of the ring gear 12 increases, the rotation of the pinion 8 becomes hard to follow the rotation of the ring gear 12 . In this moment, an inertia force of the ring gear 12 applies a force to cause the pinion 8 to rotate. Thus, an impact force occurs when such a force is transferred to the clutch gear 4 and the barrel 5 . This causes a slippage to take place between the clutch gear 4 and the barrel, thereby interrupting the impact force from being transferred to the motor 2 . Thereafter, as the ring gear 12 reaches an igniting rotational speed, the engine is started up.
As the engine is started up to cause the ignition switch to be turned off, the supply of electric power to the electromagnetic switch 9 is shutoff. In this moment, the shaft 7 and the plunger 9 a are pressed by the action of the return spring 7 c to move rearward. Upon rearward movement of the shaft 7 , the pinion 8 is disengaged from the ring gear 12 . In addition, upon rearward movement of the plunger 9 a , the contacts of the electromagnetic switch 9 are turned off, thereby shutting off the supply of electric power to the motor 2 . Accordingly, the motor 2 is turned off, thereby completing the startup operation of the engine.
Meanwhile, the drive gear 2 a , the idling gear 3 and the clutch gear 4 rotate while scattering lubricating-oil droplets in surrounding areas around these component elements. The scattered lubricating-oil droplets adhere onto the barrel 5 and its vicinity, resulting in a probability for the lubricating-oil droplets to intrude to between the clutch gear 4 and the barrel 5 .
As shown in FIG. 3 , however, the layer of grease 5 a intervenes between the clutch gear 4 and the barrel 5 and no probability takes place for the frictional coefficient to increase during the slippage between the clutch gear 4 and the barrel 5 . Thus, the clutch gear 4 and the barrel 5 absorb the rotational power in excess in a highly stabilized manner.
The starter 1 of the present embodiment mentioned above has advantageous effects as described below.
With the starter 1 of the present embodiment, even if the lubricating-oil droplets intrude to between the clutch gear 4 and the barrel 5 , the clutch gear 4 and the barrel 5 do not increase the rotational power at which a slippage occurs, while absorbing the rotational power in excess in a highly stabilized manner. This allows the starter 1 to have increased reliability in operation. The presence of grease 5 a between the solid lubricating layer 4 c of the clutch gear 4 and the outer periphery of the barrel 5 prevents a leakage of oil with a higher frictional coefficient than that of lubricating oil. This ensures grease 5 a to reliably stay in a region between the clutch gear 4 and the barrel 5 . With grease 5 a arranged to contain molybdenum disulfide, no probability exists for impurities to intrude to the region between the clutch gear 4 and the barrel 5 , thereby suppressing the occurrence of adverse affects causing the frictional coefficient to vary.
With the starter 1 of the present embodiment, further, grease 5 a contains molybdenum disulfide in a proportion ranging from 50 to 70%. This prevents a leakage of oil with a higher frictional coefficient than that of lubricating oil, while providing improvement in workability for grease to be coated 5 a onto the outer periphery of the barrel 5 .
If grease 5 a contains molybdenum disulfide in a proportion less than 50%, a leakage of oil with a higher frictional coefficient than that of lubricating oil is liable to occur. Thus, the rotational power transfer device becomes hard to ensure reliable operating characteristics for a prolonged period of time. On the contrary, if the concentration of molybdenum disulfide is greater than 70%, grease 5 a has increased viscosity, causing degraded workability to take place in coating grease 5 a onto the outer periphery of the barrel 5 . Therefore, the presence of grease 5 a containing molybdenum disulfide in a proportion ranging from 50 to 70% precludes a leakage of oil with a higher frictional coefficient than that of lubricating oil, thereby improving the workability for grease to be coated 5 a onto the outer periphery of the barrel 5 .
With the starter 1 of the present embodiment, furthermore, the solid lubricating layer, composed of the chemical coating 4 a and the molybdenum disulfide layer 4 b , is formed in a region between the clutch gear 4 and the barrel 5 . This enables further elimination of an increase in the rotational power at which a slippage is caused to occur.
While the specific embodiments of the present invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limited to the scope of the present invention, which is to be given the full breadth of the following claims and all equivalents thereof.
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A rotational power transfer device and a method of manufacturing the same are provided. The rotational power transfer device includes a first rotary member and a second rotary member. The first rotary member has an inner periphery formed with a solid lubricating layer composed of a chemical film and molybdenum disulfide. The second rotary member has an outer cylindrical periphery applied with a layer of grease including a mixture of oil with a higher frictional coefficient than that of lubricating oil and molybdenum disulfide. The second rotary member is press fitted to the first rotary member to allow the outer cylindrical periphery thereof to be placed in face-to-face relation to the inner cylindrical periphery of the first rotary member, enabling a rotational power in excess to be stably absorbed without causing any increase in the rotational power at which the slippage occurs.
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FIELD OF THE INVENTION
The present invention relates to a method and an assembly for injection moulding and, more specifically, such a method comprising introduction, under pressure, of a melt into a cavity defined by two mould halves of a mould, and a corresponding assembly.
BACKGROUND ART
Injection moulding is a common manufacturing process for producing components, such as plastic, silicone, metal or rubber components.
A conventional injection moulding assembly comprises two sections which each support a mould half. The sections are joinable by means of a unit intended for the purpose.
For injection moulding of a component, the sections, and thus also their mould halves, are brought together. The mould halves define in their joined state a cavity. A melt is introduced under pressure into the cavity and, after the necessary cooling, the sections can be divided and the completed component be ejected.
When introducing the melt into the cavity, a dividing force arises, which acts to divide the mould halves. This dividing force is the product of the pressure at which the melt is introduced into the cavity, and the surface area projected parallel to the parting plane of the mould halves. To prevent such separation of the mould halves, it is thus necessary for the mould halves to be held together by means of a locking force that is not less than said dividing force.
To achieve a high production capacity, it is common for the mould halves to define a plurality of cavities, thereby making it possible to produce a plurality of components during each injection moulding shot. Of course, the projected surface area will be larger. At an unchanged pressure, the dividing force will thus be higher.
The unit that acts to bring together the sections has a limited maximum locking force, by means of which it can hold together the sections, and therefore this unit is a limiting factor to the production capacity that can be achieved in the injection moulding assembly.
If a higher production capacity is desired, resulting in a dividing force which is higher than this maximum locking force of the unit, the components must be produced in a larger and, thus, also considerably more expensive injection moulding assembly.
CH653286 discloses a mould which to some extent solves this problem. The mould comprises a valve means which ensures that the melt during an injection moulding shot is in turn passed to separate groups of cavities. Owing to the fact that all cavities are not filled at the same time, the dividing force can be retained at an advantageously low level. However, the problem of this solution is that it necessitates a valve means, which can affect the flow configuration of the melt and, thus, also the final quality of the injection moulded components. It will also be appreciated that such sequential filling of the cavities results in the injection moulding cycle taking more time, which has a detrimental effect on the production capacity.
DE3937473 discloses an injection mould for production of undercut components. The mould comprises two semicircular mould halves, which are brought together to define a cavity together with a core. The mould halves are locked in their joined state by means of a sleeve which has an inner conical surface and which is passed over the joined mould halves, which have a complementary outer conical surface. There is no indication of how an increased production capacity is to be achieved.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an improved method and an improved assembly for injection moulding of components.
Both the method and the assembly should preferably allow production of components at an improved production capacity.
One more object is to provide a mould which is usable in such an injection moulding assembly.
One more object is to provide use of such an injection moulding assembly for producing components for a mobile phone.
Yet another object is to provide a mobile phone comprising components produced in such an injection moulding assembly.
According to the present invention, to achieve the above objects and also other objects that will appear from the following description, there are provided a method, an injection moulding assembly, a mould, a component, use of an injection moulding assembly, and a mobile phone. Preferred embodiments of the injection moulding assembly are evident from the claims.
According to the present invention, a method for injection moulding is thus provided, comprising introducing, under pressure, a melt into a cavity defined by two mould halves of a mould, said method being characterised by the steps of joining the mould halves for definition of said cavity, by moving at least one of the mould halves along a first axis, and arranging a locking means on the mould by moving along a second axis extending transversely of said first axis, said locking means having locking surfaces which grasp the mould and its joined mould halves, at least one locking surface wedgingly engaging a complementarily designed surface of the mould to cause a conversion of the force by which the locking means is arranged on the mould, into a locking force for holding the mould halves together in their joined state.
This results in an improved method for injection moulding, which allows production of components at a relatively higher production capacity. More specifically, this is achieved owing to the fact that the mould halves of the mould are brought together along a first axis, and that a locking means is then moved towards the mould along a second transverse axis and thus locks the mould halves in their joined state by means of locking surfaces which wedgingly engage complementarily designed surfaces of the mould. The wedge effect makes it possible to convert, with reinforcement, the force by which the locking means is arranged on the mould into a locking force which acts to hold together the mould halves. This reinforced locking force in turn renders is possible to enlarge, in an existing injection moulding assembly, the surface area, which is projected parallel to the parting plane of the mould halves, of the cavities which are defined by the mould halves. This enlarged surface area can be used to produce larger components or a larger number of components during an injection moulding shot in one and the same mould.
Moreover, according to the present invention an assembly for injection moulding is provided, comprising a mould with two mutually joinable mould halves which in their joined state define a cavity, a first and a second section, and a unit for bringing together said sections, said sections in their joined state being intended for locking of the mould with its mould halves in a joined state to allow introduction of a melt under pressure into said cavity, said assembly being characterised in that said mould is supported by said first section, and said second section supports a locking means comprising two separately arranged members which each have a locking surface which is engageable with a complementarily designed surface of the mould by bringing together the sections.
As a result, an assembly is provided, which allows production of components at a relatively higher production capacity. More specifically, this is achieved by said locking means, which is arrangeable on the mould by bringing together the sections. The locking means can be designed in such manner that the force by which the locking means is arranged on the mould is converted, under reinforcement, into a locking force for holding together the mould halves of the mould. As a consequence, a relatively smaller injection moulding assembly can be used to produce a given number of components per injection moulding shot or, alternatively, a relatively larger number of components can be produced per injection moulding shot in an existing injection moulding assembly.
According to a preferred embodiment the locking surfaces of the locking means are arranged in such manner that, when bringing together the sections, they grasp the mould to lock its mould halves in the joined state.
According to another preferred embodiment, at least one of said locking surfaces has a wedge angle for causing a wedging engagement with the surface which is designed complementarily thereto, when bringing together the sections. By suitably selecting said wedge angle, a reinforced locking force is achieved, which acts to hold together the mould halves. Advantageously both locking surfaces have a wedge angle.
The wedge angle is preferably less than 45° and is advantageously in the range of 1-25°.
According to yet another preferred embodiment, the members of the locking means are connected with each other. Preferably, the members are interconnected by means of a tension element, which advantageously comprises metal plates arranged on both sides of the members, said members being arranged with their locking surfaces facing each other.
According to a further preferred embodiment, the mould halves of the mould are joinable along a first axis, and the unit acts to bring together the sections along a second axis extending transversely of the first axis.
According to another preferred embodiment, a first of said mould halves is fixedly arranged and a second of said mould halves is movingly arranged.
According to another preferred embodiment, the first section is fixedly arranged and the second section is movingly arranged.
According to another preferred embodiment, the mould halves in their joined state define a plurality of cavities which are not necessarily identical. Said cavities can form separate groups which each are supplied with melt from an extruder unit.
According to another preferred embodiment, the mould comprises a plurality of pairs of mutually joinable mould halves.
According to another preferred embodiment, the first section supports a plurality of moulds. Preferably the locking means for each mould has a pair of separately arranged members which each have a locking surface.
Moreover, according to the present invention, a mould for an injection moulding assembly is provided, comprising two mutually joinable mould halves, which in their joined state define at least one cavity, said mould being characterised in that the mould is mountable on a first section of the injection moulding assembly and has external surfaces with which locking surfaces of a locking means supported by a second section of the injection moulding assembly are engageable to lock the mould with its mould halves in their joined state.
According to the present invention, also an assembly for injection moulding is provided, comprising a mould with two mutually joinable mould halves which in their joined state define a cavity, said assembly being characterised by a locking means for locking the mould with its mould halves in their joined state to allow introduction of a melt under pressure into said cavity, said locking means comprising two separately arranged engaging means and a tension element which connects said engaging means with each other, said locking means being movable to a position, in which its engaging means engage said mould during simultaneous stretching of said tension element, said stretching generating a locking force for causing said locking of the mould. According to this aspect of the present invention, the engaging means of the locking means are thus caused to engage the mould in such manner that the tension element is stretched. This results in a bias which generates a locking force that acts to lock the mould.
Moreover, according to the present invention, a method for an injection moulding is provided, comprising bringing together two sections for holding together joined mould halves of a mould, and introducing under pressure a melt into one or more cavities defined by said joined mould halves, said method being characterised by the step of bringing together the sections by means of a force which is less than the resulting force which, during introduction of the melt into or more cavities, acts to divide the mould halves.
Furthermore according to the present invention, a component produced in an injection moulding assembly as stated above is provided.
Further according to the present invention, use of an injection moulding assembly as stated above is provided for production of components for a mobile phone.
Finally, according to the present invention a mobile phone is provided, comprising components produced in an injection moulding assembly as stated above.
A number of preferred embodiments of the present invention will now be described by way of example with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic top plan view of a preferred embodiment of an inventive injection moulding assembly.
FIG. 2 is a schematic top plan view of the injection moulding assembly shown in FIG. 1 , in which two sections of the assembly are shown in their joined state.
FIG. 3 is a schematic perspective view of an embodiment of a locking means and a mould of an inventive injection moulding assembly, mould halves of the mould being shown in a divided state.
FIG. 4 is schematic perspective view of the locking means and the mould in FIG. 3 , the mould halves being shown in a joined state.
FIG. 5 is a schematic perspective view of the locking means and the mould in FIG. 3 , the locking means and the mould being shown in a joined state.
FIG. 6 is a schematic perspective view of an arrangement comprising three locking means and three moulds.
DESCRIPTION OF EMBODIMENTS
FIGS. 1 and 2 , to which reference is made, illustrate schematically a preferred embodiment of an inventive injection moulding assembly 1 .
According to the preferred embodiment, the injection moulding assembly 1 comprises an extruder unit 2 , a first section 3 , a second section 4 , and a unit 5 for bringing together the sections 3 , 4 . However, it will be appreciated that the present invention is not restricted to thus designed injection moulding assemblies.
The extruder unit 2 , which is intended for supply of a melt, preferably a plastic melt, to a mould 6 of the injection moulding assembly 1 , is of a conventional kind and will therefore not be described in detail.
The first section 3 , which is fixedly arranged, supports the above-mentioned mould 6 .
The second section 4 , which is movingly arranged, supports a locking means 7 .
The unit 5 for bringing together the sections 3 , 4 is of a conventional kind and comprises in the shown embodiment a plunger means 8 which is connected to the second section 4 for moving the same towards the first section 3 . Guide means 9 are arranged to guide the movement of the second section 4 .
The mould 6 supported by the first section 3 comprises two pairs of mould halves 10 , 11 , which are aligned with each other.
A first mould half 10 of each pair is fixedly arranged and a second mould half 11 of each pair is movingly arranged, whereby the mould halves 10 , 11 of each pair are mutually joinable.
It should be noted that the sections 3 , 4 are joined along an axis which extends transversely of the axis along which the mould halves 10 , 11 are brought together. This is illustrated more clearly in FIGS. 4 and 5 .
A recess 12 is formed in the first mould half 10 of each pair and a complementarily designed projection 13 is arranged on the second mould half 11 of each pair. The mould halves 10 , 11 of each pair will thus in their joined state define a cavity 14 for producing thin-walled components. However, it will be appreciated that the cavity defined by the mould halves need not necessarily be designed for production of thin-walled components.
The mould 6 further comprises a distributing unit 15 for distributing the melt supplied to the mould 6 to ducts 16 which pass the melt on to the respective cavities 14 .
Finally the mould 6 has a surface 17 on each side of the mould 6 , which surfaces 17 are arranged to cooperate with said locking means 7 and will be described in more detail below.
The locking means 7 comprises two separately arranged engaging means 23 . According to the shown embodiment, the engaging means 23 are in the form of separate members 18 which each have a locking surface 19 . The locking surfaces 19 are, by bringing together the sections 3 , 4 , engageable with the above-mentioned surfaces 17 of the mould 6 , the surfaces 17 of the mould 6 being designed complementarily to said locking surfaces 19 . The engaging means 23 advantageously are connected with each other by means of a tension element (not shown). The tension element will be described in more detail with reference to FIGS. 3-5 .
More specifically, the locking surfaces 19 of the members 18 are angled at an angle α relative to the axis along which the second section 14 is movable towards the first section 3 .
For injection moulding of components, the mould halves 10 , 11 of each pair are moved to their mutually joined state. Then the unit 5 for bringing together the sections 3 , 4 is operated. The locking means 7 of the second section 4 will thus grasp the mould 6 supported by the first section 3 . More specifically, the locking surfaces 19 of the locking means 7 will be engaged with the complementarily designed surfaces 17 of the mould 6 , whereby the force by which the second section 4 is moved towards the first section 3 is converted into a locking force for holding together the mould halves 10 , 11 in their joined state.
By selecting a suitable angle α of the locking surfaces 19 it is possible to achieve a reinforcement in this conversion of force.
The conversion of force achieved in each member 18 has the following relationship (without taking the loss due to friction between the surfaces 17 , 19 into consideration):
F x =F y /tan α
wherein F y is the force by which the locking surface 19 of the member 18 is engaged with the surface 17 of the mould 6 and F x is the locking force for holding together the mould halves 10 , 11 .
1/tan α forms a reinforcement factor F, which is greater than 1 if α<45°.
The angle α is preferably in the range of 1-25°, more preferred in the range 3-10° and most preferred in the range 5-8°.
Preferably the locking surfaces 19 are plane, but it will be appreciated that they can also be formed with a certain bend.
When the mould halves 10 , 11 thus are locked in their joined state, a melt can be introduced into the cavities 14 defined by the mould halves 10 , 11 . The melt can be a plastic melt for production of a plastic component. It will be appreciated, however, that also silicone, metal or rubber melts are conceivable.
It should be noted that in the shown embodiment the force acting to divide the mould halves 10 , 11 will not be greater than in the case where the mould had comprised only one pair of mould halves. The reason for this is that the pairs of mould halves are aligned with each other, whereby also the surface areas projected parallel to the respective parting planes are aligned with each other.
According to the present invention, an injection moulding assembly 1 is thus provided, which allows injection moulding of components where the force generated during injection moulding and acting to divide the mould halves 10 , 11 exceeds the force by which the sections 3 , 4 of the injection moulding assembly 1 are brought together. As described above, this is achieved in the shown embodiment with the aid of a locking means 7 , which with reinforcement acts to convert this force of bringing together into a locking force for holding together the mould halves 10 , 11 in their joined state.
In practical experiments, a locking means 7 with an angle α of 8° of the locking surfaces 19 has been used, in which case the reinforcement factor F will be about 7. This means that the production capacity of the injection moulding assembly 1 can be increased correspondingly, i.e. by a factor 7.
It will be appreciated that the gain will be significant. By modifying the mould 6 and supplementing with a locking means 7 as described above, it will thus be possible to increase the capacity in an existing injection moulding assembly. More specifically, the number of components that are produced during an injection moulding shot can be increased considerably, in the given example by a factor 7. Thus, the time of production for producing a series of products in an existing injection moulding assembly can be reduced significantly. Also the need of providing larger assemblies of higher capacity is eliminated.
FIGS. 3-5 , to which reference is now made, illustrate the locking means 7 and the mould 6 in a second preferred embodiment of the present invention.
The mould 6 comprises, like the mould described with reference to FIGS. 1 and 2 , two pairs of mould halves 10 , 11 . The mould 6 is further made up of modules, thus making it possible to easily adapt the mould to different components.
The locking means 7 comprises, in addition to the previously described engaging means 23 in the form of members 18 , also a tension element 20 , which connects the two members 18 with each other. In the embodiment shown, the tension element 20 consists of two metal plates 21 , which are attached to the sides of the members 18 in such manner that their locking surfaces 19 face each other and between them define a free space 22 .
The mould halves 10 , 11 are shown in FIG. 3 in a divided state and in FIG. 4 in a joined state. The movingly arranged mould halves 11 of each pair of mould halves 10 , 11 are moved along an axis A 1 towards the two fixedly arranged mould halves 10 .
In FIG. 5 , the locking means 7 has been brought together with the mould 6 by moving along an axis A 2 , which extends transversely of the above-mentioned axis A 1 . The locking means 7 grasps the mould 6 by the mould 6 being moved into the free space 22 between the locking surfaces 19 of the members 18 . The locking surfaces 19 engage the complementarily designed surfaces 17 of the mould 6 . The locking means 7 is advantageously arranged on the mould 6 by such a force that the converted locking force for holding together the mould halves 10 , 11 will be so great that the tension element 20 designed in the form of metal plates 21 is stretched. This results in a bias which reliably holds together the mould halves 10 , 11 during the subsequent injection moulding shot.
The present invention is particularly, but not exclusively, suitable for production of components for mobile phones, such as front and rear pieces as well as windows. The reason for this is that in many cases large series must be produced in a short time. By the present invention making it possible to increase the capacity, by means of the above-described modifications, in an existing injection moulding assembly, it is possible to use an existing plant of injection moulding assemblies for producing such large series in a short time.
According to the present invention, an injection moulding assembly 1 is thus provided which generates high locking forces using simple means. More specifically, this is achieved owing to a locking means 7 which locks the mould halves 10 , 11 of the mould 6 in a joined state. The locking means 7 comprises engaging means 23 which engage the mould 6 during simultaneous stretching of a tension element 20 which connects the engaging means 23 with each other. Such stretching generates a locking force which holds together the mould halves 10 , 11 during the injection moulding process. By designing, for instance, the engaging means 23 in the form of wedge-shaped members 18 , it will be possible to use the unit 5 that is available in conventional injection moulding assemblies for bringing together the sections 3 , 4 of the assembly and convert the force necessary for bringing together the sections 3 , 4 , during simultaneous reinforcement, into a force for locking the mould halves 10 , 11 of the mould 6 .
It will appreciated that the present invention is not restricted to the embodiments illustrated.
For instance, it is possible to let the first section support a plurality of moulds, in which case a corresponding number of locking means can be arranged to lock the mould halves of the mould in their joined state. Such an arrangement of moulds 6 and locking means 7 is schematically shown in FIG. 6 .
It will also be appreciated that each mould may comprise only one pair of mould halves or more than two pairs of mould halves.
Further it will be appreciated that each pair of mould halves can define a plurality of cavities which are not necessarily identical. For instance, it is possible to arrange two extruder units of the injection moulding assembly, each extruder units being arranged to supply a group of mutually identical cavities with a melt. As a result, simultaneous production of, for instance, front and rear pieces for mobile phones in one and the same injection moulding assembly is allowed. The capability of the injection moulding assembly will also be improved since the number of products per process will be smaller.
Finally, it will be appreciated that the locking means need not be designed in the manner described above. For example, it is possible to provide only the locking surface of one member with a wedge angle α.
Consequently, several modifications and variations are feasible, which means that the scope of the invention is exclusively defined by the appended claims.
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A method for injection moulding, comprising introducing, under pressure, a melt into a cavity ( 14 ) defined by two mould halves ( 10, 11 ) of a mould ( 6 ). The method is characterized by the steps of joining the mould halves ( 10, 11 ), for definition of said cavity ( 14 ), by moving at least one of the mould halves ( 11 ) along a first axis, and, by moving along a second axis extending transversely of said first axis, arranging a locking means ( 7 ) on the mould ( 6 ). The locking means ( 7 ) has locking surfaces ( 19 ) which grasp the mould ( 6 ) and its joined mould halves ( 10, 11 ), at least one locking surface ( 19 ) wedgingly engaging a complementarily designed surface ( 17 ) of the mould ( 6 ) to cause conversion of the force by which the locking means ( 7 ) is arranged on the mould ( 6 ), into a locking force for holding together the mould halves ( 10, 11 ) in their joined state. The present invention also concerns an injection moulding assembly as well as a mould for injection moulding assemblies.
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This application is a 371 of PCT/IB2006/002436 filed on Sep. 5, 2006, published on Mar. 15, 2007 under publication number WO 2007/029092 A1 which claims priority benefits from French Patent Application Number 05 09123 filed Sep. 7, 2005, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
The invention relates to a parking garage that is at least partially automatic making it possible to park a plurality of vehicles in a restricted volume.
Conventional, nonautomatic parking garages consist of parking spaces that can be accessed via a roadway traveled by the vehicle being driven by its driver. These spaces can all be accessed via roadways which represent a considerable proportion of the total surface area of the garage. In addition, a sufficient clearance has to be provided around each space to allow a vehicle to maneuver and position itself easily, while allowing its driver to get out of his vehicle. The disadvantage of these parking garages therefore arises from the fact that a very considerable surface area is reserved for accessing the various parking spaces and cannot be directly used for parking vehicles.
To remedy these disadvantages, there are automatic parking garages in which a driver positions his vehicle at an entrance point, this vehicle then being conducted automatically to its parking space.
A first solution is described in document FR2641020, in which a driver positions his vehicle at the entrance in a vertical elevator. This elevator, that can be moved horizontally, is then capable of positioning the vehicle in its final parking space, in the chosen column and at the chosen height. The vehicle is released in a similar manner via the elevator. The first disadvantage of this solution is its cost due to the use of a complex elevator. In addition, the total number of parking spaces remains limited since the garage is limited to a two-dimensional vertical geometry.
Document FR27000354 proposes a parking garage on a horizontal surface in which each vehicle is positioned on a platform that can be moved transversely. The first disadvantage of this solution is that the garage is limited to a two-dimensional horizontal geometry. Its second disadvantage is its complexity and its high cost since each vehicle is positioned on an independent movable platform. A third disadvantage arises from the nonoptimization of the available surface area: specifically, an entire row must always be free for allowing access to the most distant spaces, and in addition each row must have a width compatible with the longest vehicle admitted to park: a considerable surface area not occupied by the shortest vehicles remains unused.
Document U.S. Pat. No. 5,678,972 describes a three-dimensional garage solution based on a combination of horizontal platforms and elevators as in the preceding solutions. This solution, although three-dimensional, combines the other disadvantages mentioned above.
Finally, document U.S. Pat. No. 3,040,913 describes an automatic car park in which vehicles enter through an entrance where they are positioned on a platform and raised to a predefined floor by a first elevator. The placement on the chosen floor is carried out from a choice of several parking lines. The exit is similar, via a second elevator. All the movements of the platforms supporting the vehicles are made by automatic driving means. One disadvantage of this solution arises from the fact that two elevators are necessary, one for the entrance and the other for the exit. Furthermore, a second disadvantage arises from the fact that all the vehicle movements are carried out by means of a movable platform on which the vehicle is parked, which induces a costly infrastructure.
BRIEF SUMMARY OF THE INVENTION
The object of the present invention consists in proposing an at least partially automatic parking garage that does not have the foregoing disadvantages.
More precisely, a first subject of the present invention consists in a parking garage that optimizes the available surface area and makes it possible to park a maximum of vehicles in the smallest volume.
A second subject of the present invention consists in a parking garage that is simple and low cost.
A third subject of the present invention is a parking garage that is compatible with a three-dimensional dimension.
A fourth subject of the present invention consists in a method of access to a space or to a vehicle in a space in a parking garage.
The invention achieves the above aims by proposing a parking garage that is at least partially automatic, comprising at least one floor comprising parking lanes separated by lateral limits, characterized in that each parking lane comprises a driving means for directly driving the wheels of a vehicle in order to move the vehicle in the longitudinal direction up to a free space and in that the entrance and/or exit ends of the parking lanes are connected to a transport means consisting in one or more platforms traveling on rails allowing the vehicles to automatically enter and exit the parking lanes, at least one floor being at least partially surrounded by rails.
The invention is more precisely defined by the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
These subjects, features and advantages of the present invention will be explained in detail in the following description of a particular embodiment made in a nonlimiting manner with reference to the attached figures amongst which:
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 represents schematically a partially occupied parking garage according to a first two-dimensional embodiment of the invention;
FIGS. 2 to 4 illustrate schematically the method of accessing a vehicle according to a first two-dimensional embodiment of the invention;
FIG. 5 represents schematically the fully occupied parking garage according to the first two-dimensional embodiment of the invention;
FIG. 6 represents schematically a parking garage according to a second three-dimensional embodiment of the invention;
FIG. 7 represents a top schematic view of a variant device for automatic movement of a vehicle in a parking line;
FIG. 8 represents a front view of the device for automatic movement of a vehicle according to the variant of FIG. 7 ;
FIG. 9 represents a top view of the device for automatic movement of a vehicle according to the variant of FIG. 7 ;
FIG. 9A represents a side view of the device for automatic movement of a vehicle according to the variant of FIG. 9 ;
FIG. 10 represents a variant of a device for orienting a vehicle in a parking line;
FIG. 11 represents a variant embodiment of the first mode of execution of the invention of FIG. 1 ;
FIG. 12 represents a second variant embodiment of the first mode of execution of the invention of FIG. 1 .
FIG. 1 illustrates a mode of execution of the parking garage placed on a single floor, on a horizontal and rectangular surface 1 . This garage can be accessed via an entrance 2 placed on a first side of the rectangle and the vehicles may exit the garage via an opposite exit 3 . The surface 1 is divided into parking lanes 4 corresponding approximately to the width of the widest vehicle admitted. These lanes 4 are delimited by separations 5 that serve as obstacles and as means of guidance for the vehicles 6 , placed one after the other in the longitudinal direction of the parking lane, that is to say the front and rear of the vehicle being oriented toward the ends of the parking lane 4 . Each parking lane 4 is fitted with automatic driving means 7 of the vehicles 6 in order to guide them to the free location closest to the exit 3 on its parking lane 4 . In this mode of execution, this driving means consists in conveyor belts 7 placed one after the other so as to form two virtually continuous lateral lanes on each parking lane 4 , the location of these conveyor belts corresponding to the position of the wheels of the vehicles 6 .
FIGS. 7 to 9A which will be explained below illustrate a variant device for deriving the vehicles.
According to the invention, the parking lanes are surrounded by a transport means that consists in platforms 8 that can be moved on rails 9 , according to the transport means known as the “flat car” making it possible to connect the two ends, entrance and exit, of the parking lanes 4 . The entrance of a vehicle into the parking garage is carried out by it being positioned facing one of the parking lanes 4 comprising free spaces. Then, it is moved forward automatically by the driving means 7 which drive it until it makes contact with the last vehicle of the lane or contact with a retractable stop at the end of the lane if it is entirely free. Access to the parking lanes 4 is achieved by a platform 8 a traversing a free space which serves as a gangway for access to the garage in this configuration, from the entrance 2 . The vehicle is left by its driver with the handbrake off and the wheels straight. The rails have been represented in a rectangular shape for reasons of space but may have a more rounded shape in order to make it easier to turn the corners.
According to a variant embodiment, note that the entrance 2 of the vehicles is moved away into a location farther away from the parking garage 1 , a vehicle being positioned on a platform 8 at this entrance 2 , then taken automatically by this platform 8 up to the parking garage 1 itself. This solution therefore offers the advantage of great flexibility since it is possible to physically separate the infrastructures for access to the parking garage from the garage itself. Similarly, the exit from the garage may also be physically separated from the garage.
FIGS. 2 to 4 illustrate schematically the method of retrieving a vehicle C parked in the third position in its parking lane 4 . A free space on a platform 8 b is placed opposite the end of this parking lane 4 and the driving means 7 drive the first vehicle A to this free space of the platform 8 b , the vehicle being positioned transversely to the direction of movement of the platform, as is illustrated in FIG. 2 . A new free space of the platform 8 b is again placed opposite this parking lane in order to drive the vehicle B thereto, as illustrated in FIG. 3 . The vehicle C then occupies the first position of its parking lane 4 , its movement being caused by the driving means 7 of the parking lane. It is then sufficient to again place a free space of a movable platform 8 a opposite this vehicle C in order to allow it to move forward and cross the space separating it from the exit 3 . In this exit phase, the platform 8 a plays the role of a gangway between the parking garage 1 and the exit 3 , and allows the exiting movement of the vehicle with the aid of the driving means of the conveyor belt type 10 that it comprises. Note, if all the spaces on the platforms 8 are occupied, it is possible to reinsert vehicles from these platforms into free spaces of the parking lanes 4 via the entrance side 2 . For this, the platform is positioned opposite the entrance of the parking lanes 4 on the side of the entrance 2 of the parking garage, and the driving means 10 of the platform 8 make it possible to automatically drive a vehicle to free spaces of a parking lane 4 .
The invention also relates to a method for accessing a space of a parking garage according to the invention thanks to the following steps, explained in detail below:
automatic driving of the vehicle 6 from the entrance 2 into a parking lane 4 ; positioning of the vehicle in the longitudinal direction in contact with a preceding vehicle or a retractable stop placed at the end of the parking lane 4 .
The invention also relates to a method for retrieving a vehicle from a parking garage according to the invention thanks to the following steps, explained in detail below:
positioning of a free space of a platform 8 at the end of the parking lane 4 where the vehicle 6 to be retrieved is positioned; automatic driving and positioning of the first vehicle of the parking lane 4 on this platform 8 ; repetition of the above two steps until the vehicle to be retrieved is positioned on a platform 8 ; transport of the vehicle 6 to be retrieved by the platform 8 to the exit 3 of the parking garage.
FIG. 5 illustrates a variant execution of this first mode of execution of the invention, comprising a multitude of platforms 8 a , 8 b , 8 c , 8 d , in a maximum filling configuration.
Finally, the solution described above satisfies the objects of the invention because it has the following advantages:
in each parking lane, the vehicles can be placed one against the other in a longitudinal direction, without wasting space between the vehicles, according to a solution independent of the variable length of the vehicles; the parking lanes have a width that is slightly greater than the maximum authorized width. Since almost all the vehicles have substantially equivalent widths, very little surface area is wasted between the vehicles and the lateral limits 5 of each parking lane 4 , irrespective of the vehicle type; the means for driving the vehicles in the parking lanes are simple and the solution is not very costly, since this driving is based on setting in motion the vehicle's own wheels, with no intermediate truck or platform; the means for moving the vehicles around the garage are also relatively simple and also fulfill the second function of additional parking spaces.
The same concept may be applied to three-dimensional configurations, that is to say to parking garages consisting of several floors, each floor having a structure similar to the mode of execution described above. In the exemplary embodiment illustrated in FIG. 6 , the parking garage consists of an upper floor 1 a comprising the entrances 2 and exits 3 of the parking garage and a lower floor 1 b . Each floor is surrounded by movable platforms 8 mounted on rails 9 , these rails also forming an up ramp 9 c and a down ramp 9 d , in order to automatically move vehicles from the lower floor to the upper floor and vice versa. These ramps connect the closed circuits 9 a and 9 b respectively of the upper floor la and lower floor 1 b , allowing the platforms to circulate around these floors. Switches are provided at the junction between the ramps 9 c and 9 d and the closed circuits 9 a and 9 b . This three-dimensional configuration naturally makes it possible to provide more parking spaces on a reduced ground surface area. The parking spaces of the lower floor 1 b are filled by the vehicles being guided by a platform 8 , taking the down ramp 9 d from the upper floor 1 a , being positioned on the rails 9 b along the side facing the entrance of the parking lanes 4 of the lower floor 1 b . Then the vehicles are positioned in this parking lane by the driving means 10 of the platform then by the driving means 7 of the parking lane. A vehicle is returned to the exit by repositioning it on the platform 8 , according to a method similar to that described with reference to FIGS. 2 to 4 , then by raising it to the exit 3 on the upper floor 1 a by taking the up ramp 9 c.
The whole parking garage may be managed by a software program on a central server, storing the positioning of each vehicle parked in the garage, computing according to the best possible algorithm the movements of the platforms in order to optimize the distribution of the vehicles and the method for retrieving vehicles.
FIGS. 7 to 9A illustrate a variant driving device 7 of the vehicles within the parking lanes 4 and on the platforms 8 , allowing the vehicles to move on their own wheels 20 . The driving device is based in driving cables 11 positioned on the center of each parking lane 4 and set in motion by pulleys 12 positioned at the ends of the lanes. This device also comprises a double rail 13 , distributed either side of the driving cable 11 and approximately 30 centimeters apart.
This device allows the driving of a rider which interacts with a motor vehicle to set it in motion. A rider comprises a chassis with four wagon wheels 14 traveling on the rails 13 , incorporating a braking device and external wheels 15 , connected to the wheels 14 by a drive roller 16 . The outer wheels 15 are capable of adjusting the height of the drive roller 16 relative to the ground. The rider is finally set in motion in a chosen direction by a pair of hydraulic calipers 17 , whose operation is similar to that of disk brake calipers, which lower like a rider on a cable 11 corresponding to the chosen direction.
The drive rollers 16 interact directly with the wheels 20 of a motor vehicle. For this, they are advantageously fluted and rotated in the direction contrary to the sought rotation of the wheels of the vehicle, by means of a shuttle-shaped roller 18 that interacts with the cable 11 going in the direction opposite to that of the vehicle.
The drive rollers 16 in contact with the wheels 20 of the vehicle impose thereon a rotary motion, in the direction opposite to that of the rollers 16 , by the tangential force of contact that is added to the driving force itself. This combination of driving and rotation forces makes it possible to set the vehicle in motion gently, particularly in a startup phase.
To fulfill their function of driving the motor vehicles, a rider is placed under each vehicle. For that, a free rider is placed on the platform 8 at the entrance 2 of the parking garage, in a slight depression of its rail 13 . A vehicle arriving in the garage will therefore be positioned above the rider so that the rider is placed between the two front and rear axles of the vehicle. This interaction between the rider and the vehicle will last throughout the parking of the vehicle within the parking garage, whether it is positioned in a parking lane 4 or on a platform 8 . The vehicle will therefore be set in motion by an interaction of the rider with a driving cable 11 . The rider associated with a vehicle may serve as an identification of the vehicle for managing the position of the vehicles, access to the free spaces and their retrieval.
As a variant, the association of a vehicle with a rider could be organized upstream of the platforms 8 , in specific entrance boxes where the drivers would collect or leave their vehicles.
As a comment, a vehicle is moved from a platform 8 to a parking lane 4 by setting the rider in motion initially on the platform 8 , its front caliper 17 latching onto the cable 11 of the platform 8 when it reaches its end, the vehicle then being moved by the rear caliper 17 again in interaction with the cable 11 of the platform until the front caliper 17 arrives in interaction with the cable 11 of the parking lane 4 . Then, the rear caliper 17 is also separated from the cable of the platform 8 to take hold of the cable of the parking lane. The same principle is used for the inverse movement of a vehicle from a parking lane to a platform. Vertically retractable bollards may be provided at the ends of the platforms 8 and of the parking lanes 4 . On the platforms 8 , this bollard may serve as a stop indicating the correct positioning of a vehicle, particularly relative to its rider, the rollers then coming into contact with the vehicle wheels.
One advantage of this principle therefore arises from the fact that a motor vehicle moves on its own wheels in the parking lanes and may come directly into contact with the preceding vehicle, which best optimizes the park space. Therefore, there is no need for a complex structure for setting in motion a platform in the whole parking garage, supporting a vehicle that is passively immobile on this platform. Platforms are used only over a small surface area, partially surrounding a set of parking lanes.
There are many variant embodiments of a driving device as described in FIGS. 7 to 9 . For example, this device may be simplified by removing the rotary movement of the drive rollers 16 and therefore the shuttles 18 . In addition, the movement of the riders will be controlled by intelligent electronic devices, taking into particular account the length of the vehicles in order to optimize their positioning. In addition, a device making it possible to adjust the width of the lanes may be implemented in order to be able to adapt the garage to a change in the dimensions of the vehicles to be parked. For this, the vehicles could be placed in the parking lanes on traffic lanes consisting of movable plates, being able more or less to be superposed in order to reduce or increase the width of the lane.
According to an advantageous option, a trajectory correction device may be used, as illustrated in FIG. 10 . Specifically, since the motor vehicles move on their own wheels, it is important for their wheels to be very straight in order to obtain a sufficiently rectilinear trajectory. For this, a slight deviation in trajectory may be corrected by placing at regular intervals strips of conveyor belt 19 spaced perpendicularly to the longitudinal direction of the parking lanes in order to cause a transverse movement of the wheels of a vehicle in order to recenter it if necessary.
According to an advantageous variant embodiment of a parking garage according to the concept of the invention, it is possible to envisage the movement of the platforms 8 on rails 9 in two opposing directions, and the movement of the vehicles within a parking lane in both directions. Such a variant makes it possible to reduce the obligatory distance of the rails 9 , and makes it possible to increase the possibilities of managing the vehicles for one and the same rail distance. Specifically, since the platforms 8 may move in both directions on the rails 9 , there is no obligation to produce a closed circuit. This makes it possible to provide a single entrance/exit door instead of two doors, one for entering and the other for exiting. In the case of a garage with several floors, a single ramp is sufficient for the movement from one floor to another. This variant also makes it possible to optimize the methods for accessing the parking spaces and for retrieving the vehicles. Specifically, if a vehicle is on a platform 8 close to one end of the rails 9 , it is not necessary to make it travel along all of the rails 9 to reach the exit but, on the contrary, a short movement in the reverse direction is possible. This variant therefore makes it possible to reduce the distance traveled by a vehicle. As a comment, the use of two calipers at the front and at the rear of the vehicle in the embodiment of movement with the aid of riders, as described previously with reference to FIGS. 7 to 9 , allows this movement of the vehicle in the two opposing directions.
FIG. 11 illustrates a first application of such a variant according to a two-dimensional diagram. In this solution, the rails 9 extend only over one side of the parking lanes 4 , and comprise an end 2 , 3 which fulfills the functions of both vehicle entrance and exit.
FIG. 12 illustrates a second application of such a variant in which the parking lanes 4 are surrounded by two circuits of independent rails 9 , that may cross. Such a layout makes it possible to offer two entrance/exit zones 2 , 3 of the garage and increases the possibilities of movement of a vehicle.
According to another application not shown, the rails 9 could make a complete circuit of the parking garage, switches being implemented to choose the direction to an entrance/exit 2 , 3 or the movement around the parking garage.
Finally, this concept may be applied in parking garages occupying several floors, the ramps then playing the combined role of up and down ramp. This therefore makes it possible to reduce by half the number of ramps and greatly simplify the overall structure.
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The invention concerns a parking lot at least partly automatic comprising at least one floor ( 1; 1 a, 1 b ) including parking lanes ( 4 ) separated by lateral boundaries ( 5 ), characterized in that each parking lane ( 4 ) comprises one or more driving means ( 7 ) to drive a vehicle in the longitudinal direction up to a free place and in that the entry and exit ends of the parking lanes ( 4 ) are connected to transport means ( 8, 9 ) allowing the automatic entry and exit of the vehicles in and out of the parking lanes ( 4 ).
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FIELD OF INVENTION
[0001] The invention concerns the use of bleaching solutions.
BACKGROUND OF THE INVENTION
[0002] Raw cotton (gin output) is dark brown in colour due to the natural pigment in the plant. The cotton and textile industries recognise a need for bleaching cotton prior to its use in textiles and other areas. The object of bleaching such cotton fibres is to remove natural and adventitious impurities with the concurrent production of substantially whiter material.
[0003] There have been two major types of bleach used in the cotton industry. One type is a dilute alkali or alkaline earth metal hypochlorite solution. The second type of bleach is a peroxide solution, e.g., hydrogen peroxide solutions. This bleaching process is typically applied at high temperatures, i.e. 80 to 95° C. Controlling the peroxide decomposition due to trace metals is key to successfully using hydrogen peroxide. Often Mg-silicates or sequestering agents such as EDTA or analogous phosphonates are applied to reduce decomposition. A problem with the above types of treatment is that the cotton fibre is susceptible tendering.
[0004] Wood pulp produced for paper manufacture either contains most of the originally present lignin and is then called mechanical pulp or it has been chiefly delignified, as in chemical pulp. Mechanical pulp is used for e.g. newsprint and is often more yellow than paper produced from chemical pulp (such as for copy paper or book-print paper). Further, paper produced from mechanical pulp is prone to yellowing due to light- or temperature-induced oxidation. Whilst for mechanical pulp production mild bleaching processes are applied, to produce chemical pulp having a high whiteness, various bleaching and delignification processes are applied. Widely applied bleaches include elemental chlorine, hydrogen peroxide, chlorine dioxide and ozone.
[0005] Whilst for both textile bleaching and wood pulp bleaching, chlorine-based bleaches are most effective, there is a need to apply oxygen-based bleaches for environmental reasons. Hydrogen peroxide is a good bleaching agent, however, it needs to be applied at high temperatures and long reaction times. For industry it is desirable to be able to apply hydrogen peroxide at lower temperatures and shorter reaction times than in current processes. Towards this end, the use of highly active bleaching catalysts would be desirable.
[0006] As a particular class of active catalysts, the azacyclic molecules have been known for several decades, and their complexation chemistry with a large variety of metal ions has been studied thoroughly. The azacyclic molecules often lead to transition-metal complexes with enhanced thermodynamic and kinetic stability with respect to metal ion dissociation, compared to their open-chain analogues.
[0007] United States Application 2001/0025695, discloses the use of a manganese transition metal catalyst of 1,4,7-Trimethyl-1,4,7-triazacyclononane (Me 3 -TACN); the transition metal catalyst has as a non-coordinating counter ion PF 6 − . United States Application 2001/0025695A1 also discloses a manganese transition metal catalyst of 1,2-bis-(4,7-dimethyl-1,4,7-triazacyclonon-1-yl)-ethane (Me 4 -DTNE); the transition metal catalyst has as a non-coordinating counter ion ClO 4 − . The solubility, in water at 20° C., of the Me4-DTNE complex having non-coordinating counter ion ClO 4 − is about 16 gram/Liter. The solubility, in water at 20° C., of the Me4-DTNE complex having non-coordinating counter ion PF 6 − is about 1 gram/Liter.
[0008] US 2002/0066542 discloses the use of a manganese transition metal complex of Me 3 -TACN in comparative experiments and makes reference to WO 97/44520 with regard to the complex; the non-coordinating counter ion of the manganese transition metal complex of Me 3 -TACN is PF 6 − . The X groups as listed in paragraph [021] of US 2002/0066542 are coordinating.
[0009] EP 0458397 discloses the use of a manganese transition metal complex of Me 3 -TACN as bleaching and oxidation catalysts and use for paper/pulp bleaching and textile bleaching processes. Me 3 -TACN complexes having the non-coordinating counter ion perchlorate, tetraphenyl borate (BPh 4 − ) and PF 6 − are disclosed. The solubility, in water at 20° C., of the Me 3 -TACN complex having non-coordinating counter ion ClO 4 − is between 9.5 to 10 gram/Liter. The solubility, in water at 20° C., of the Me 3 -TACN complex having non-coordinating counter ion BPh 4 − is less then 0.01 gram/Liter.
[0010] WO 95/27773 discloses the use of manganese transition metal catalysts of 1,4,7-Trimethyl-1,4,7-triazacyclononane (Me 3 -TACN); the transition metal catalysts have as a non-coordinating counter ion ClO 4 − and PF 6 − .
[0011] 1,4,7-Trimethyl-1,4,7-triazacyclononane (Me 3 -TACN) has been used in dishwashing for automatic dishwashers, SUN™, and has also been used in a laundry detergent composition, OMO Power™. The ligand (Me 3 -TACN) is used in the form of its manganese transition-metal complex, the complex having a counter ion that prevents deliquescence of the complex. The counter ion for the commercialised products containing manganese Me 3 -TACN is PF 6 − . The Me 3 -TACN PF 6 − salt has a water solubility of 10.8 g per litre at 20° C. Additionally, the perchlorate (ClO 4 − ) counter ion is acceptable from this point of view because of its ability to provide a manganese Me3-TACN that does not appreciably absorb water. Reference is made to U.S. Pat. No. 5,256,779 and EP 458397, both of which are in the name of Unilever. One advantage of the PF 6 − or ClO 4 − counter ions for the manganese Me 3 -TACN complex is that the complex may be easily purified by crystallisation and recrystallisation from water. In addition, for example, the non-deliquescent PF 6 − salt permits processing, e.g., milling of the crystals, and storage of a product containing the manganese Me 3 -TACN. Further, these anions provide for storage-stable metal complexes. For ease of synthesis of manganese Me 3 -TACN highly deliquescent water soluble counterions are used, but these counterions are replaced with non-deliquescent, much less water soluble counter ions at the end of the synthesis. During this exchange of counter ion and purification by crystallisation loss of product results. A drawback of using PF 6 − is its significant higher cost compared to other highly soluble anions.
[0012] U.S. Pat. Nos. 5,516,738 and 5,329,024 disclose the use of a manganese transition metal catalyst of 1,4,7-Trimethyl-1,4,7-triazacyclononane (Me 3 -TACN) for epoxidizing olefins; the transition metal catalyst has as a non-coordinating counter ion ClO 4 − . U.S. Pat. No. 5,329,024 also discloses the use of the free Me 3 -TACN ligand together with manganese chloride in epoxidizing olefins.
[0013] WO 2002/088063, to Lonza AG, discloses a process for the production of ketones using PF 6 − salts of manganese Me 3 -TACN.
[0014] WO 2005/033070, to BASF, discloses the addition of an aqueous solution of Mn(II)acetate to an aqueous solution of Me 3 -TACN followed by addition of a organic substrate followed by addition of hydrogen peroxide.
[0015] Use of a water-soluble salt negates purification and provides a solution, which may be used directly, and reduces loss by purification.
SUMMARY OF INVENTION
[0016] We have found that there is an advantage in using a preformed transition metal complex of azacyclic molecules over in situ generation, for example by mixing the appropriate ligand with the MnCl 2 , MnSO 4 or Mn(OAc) 2 salts in an industrial process. Further, the addition of one product to a reaction vessel reduces errors in operation.
[0017] We have found that for certain applications the use of a highly water-soluble salt of the manganese azacyclic complex is preferable. We have found that the dominant factor in the solubility of these transition metal complexes is the non-coordinating counter ion(s). In the solubilities given herein for (Me 3 -TACN) the co-ordinating counter ions are three O 2− and for Me 4 -DTNE the co-ordinating counter ions are two O 2− and one acetate.
[0018] The invention is particularly applicable to industrial bleaching of paper/pulp, cotton-textile fibres, and the removal or degradation of starches. By using a transition metal catalyst that is significantly water soluble the synthesis negates the preparation of significantly water insoluble salts and hence reduces cost. The transition metal catalyst may be shipped in solution or as a solid form of transition metal catalyst which is easily dissolved in water.
[0019] In order to avoid the use of costly non-coordinating counter ions required for isolation, formulation and stabilisation, one might form the transition metal catalyst in situ. U.S. Pat. No. 5,516,738 discloses the use of free Me 3 -TACN ligand with Mn(II)Cl 2 in epoxidizing olefins. However the in situ preparation has some drawbacks, for example, it is a more complicated process and uncontrolled side reactions occur which result in less efficient formation of the catalyst and undesirable side products like MnO 2 . Fast decomposition of hydrogen peroxide, catalysed by some of the undesirable side products might occur, reducing the efficiency of the bleach process.
[0020] In one embodiment the present invention provides a method of catalytically treating a substrate, the substrate being a cellulose-containing substrate or starch containing substrate, with a preformed transition metal catalyst salt, the preformed transition metal catalyst salt having a non-coordinating counter ion, the method comprising the following steps:
[0000] (i) optionally dissolving a concentrate or solid form of a preformed transition metal catalyst salt in an aqueous medium to yield an aqueous solution of the preformed transition metal catalyst salt;
(ii) adding the aqueous solution of the preformed transition metal catalyst salt to a reaction vessel; and,
(iii) adding hydrogen peroxide to the reaction vessel,
wherein the preformed transition metal catalyst salt is a mononuclear or dinuclear complex of a Mn (III) or Mn(IV) transition metal catalyst for catalytically treating the substrate with hydrogen peroxide, the non-coordinating counter ion of said transition metal selected to provide a preformed transition metal catalyst salt that has a water solubility of at least 30 g/l at 20° C. and wherein the ligand of the transition metal catalyst is of formula (I):
[0000]
[0000] wherein:
[0000]
[0000] p is 3;
R is independently selected from: hydrogen, C1-C6-alkyl, CH 2 CH 2 OH, and CH 2 COOH, or one of R is linked to the N of another Q via an ethylene bridge;
R1, R2, R3, and R4 are independently selected from: H, C1-C4-alkyl, and C1-C4-alkylhydroxy, and the substrate is bought into contact with a mixture of the aqueous solution of the preformed transition metal catalyst salt and the hydrogen peroxide. The dinuclear complex may have two manganese in same or differing oxidation states.
[0021] R is preferably C1-C6-alkyl, most preferably Me, and/or one of R is an ethylene bridge linking the N of Q to the N of another Q.
[0022] The reaction vessel may be part of a continuous flow apparatus or a vessel used in a batch process. Preferably pulp and cotton are treated in a continuous flow process. Steps (ii) and (iii) provide a mixture of the aqueous solution of the preformed transition metal catalyst salt and the hydrogen peroxide; the substrate is bought into contact with this mixture and hence is treated with such within the reaction vessel.
[0023] The preformed transition metal catalyst salt is one which has been provided by bringing into contact the free ligand or protonated salt of the free ligand and a manganese salt in solution followed by oxidation to form a Mn (III) or Mn(IV) transition metal catalyst. Preferred protonated salts of the ligand are chloride, acetate, sulphate, and nitrate. The protonated salts should not have undesirable counterions such as perchlorate or PF 6 − . The contact and oxidation step is preferably carried out in an aqueous medium, at least 24 hours before use, preferably at least 7 days before use.
[0024] The rate of formation of the transition metal catalyst depends upon the ligand. The formation of a transition metal catalyst from Me 3 -TACN ligand is typically complete within 5 min. The formation of a transition metal catalyst from Me 4 -DTNE ligand requires about 20 to 30 min for optimal complexation. After complex formation an aqueous solution of H 2 O 2 /NaOH may be slowly added to form a desired Mn(IV)/Mn(IV) or Mn(IV)/Mn(III) species. This second step, the oxidation step, provides a sufficiently stable complex for storage.
[0025] In another aspect the present invention provides the preformed transition metal catalyst salt as defined herein, wherein the preformed transition metal catalyst salt has been formed by a contact and oxidation step that is carried out at least 24 hours previously, preferably 7 days previously, and is stored in a closed, preferably sealed, container.
[0026] The present invention also extends to the substrate treated with preformed transition metal catalyst and hydrogen peroxide.
DETAILED DESCRIPTION OF THE INVENTION
[0027] The solubility, in water at 20° C., of the Me 3 -TACN complex having non-coordinating counter ion acetate is more than 70 gram/Liter. The solubility, in water at 20° C., of the Me 3 -TACN complex having non-coordinating counter ion sulphate is more than 50 gram/Liter. The solubility, in water at 20° C., of the Me 3 -TACN complex having non-coordinating counter ion chloride is 43 gram/Liter. It is most preferred the preformed transition metal catalyst salt is a dinuclear Mn(III) or Mn(IV) complex with at least two O 2− bridges.
[0028] The method of treating paper/pulp, cotton-textile fibres, or starch containing substrate is most applicable to industrial processes. Other examples of such processes are laundry or mechanical dish washing applications, fine chemical synthesis. Most preferably the method is applied to wood pulp, raw cotton, or industrial laundering. In this regard, the wood pulp is bleached which has not been processes into a refined product such as paper. The raw cotton is in most cases treated/bleached after preparation of the raw cotton cloths or bundled fibres. Preferably the method of treatment is employed in an aqueous environment such that the liquid phase of the aqueous environment is at least 80 wt % water, more preferably at least 90 wt % water and even more preferably at least 95 wt % water. After treatment of the substrate the reactants may be recycled back into the reaction vessel.
[0029] In addition, poly-cotton may also advantageously be treated in the form of a thread or a woven garment. Another preferred utility is in the industrial bleaching market of laundry, for example, the bleaching of large amounts of soiled white bed linen as generated by hospitals and gaols.
[0030] Preferably R is independently selected from: hydrogen, CH 3 , C 2 H 5 , CH 2 CH 2 OH and CH 2 COOH; least preferred of this group is hydrogen. Most preferably R is Me and/or one of R is an ethylene bridge linking the N of Q to the N of another Q. Preferably R1, R2, R3, and R4 are independently selected from: H and Me. Preferred ligands are 1,4,7-Trimethyl-1,4,7-triazacyclononane (Me 3 -TACN) and 1,2-bis-(4,7-dimethyl-1,4,7-triazacyclonon-1-yl)-ethane (Me 4 -DTNE) of which Me 3 -TACN is most preferred. The manganese ion is most preferably Mn(III) or Mn(IV), most preferably Mn(IV).
[0031] The water solubility of the preformed transition metal catalyst salt is at least 30 g/l at 20° C., more preferably at least 50 g/l at 20° C. Even more preferably the water solubility of the preformed transition metal catalyst salt is at least 70 g/l at 20° C. and most preferably the salt is deliquescent. The high solubility provides for concentrates whilst avoiding precipitation or crystallisation of the preformed transition metal catalyst salt. The preformed transition metal catalyst salt (cationic) used in the method is most preferably a single species. In this regard, the aqueous solution used comprises at least 90% of a single species. The non-coordinating counter ions may, for example, be a mixture of acetate and chloride.
[0032] The non-coordinating anion of the transition metal catalyst salt is preferably selected from the group consisting of chloride, acetate, sulphate, and nitrate. Most preferably the salt is acetate. The salt is other than the perchlorate.
[0033] Co-ordinating counter ions for the transition metal complexes are O 2− and/or carboxylate (preferably acetate). It is preferred that the transition metal complexes have at least one O 2− co-ordinating counter ion. In particular, for Me 3 -TACN three O 2− co-ordinating counter ions are preferred or one O 2− co-ordinating counter ion and two carboxylate co-ordinating counter ions are preferred, with two acetate moieties as co-ordinating counter ions being most preferred. For Me 4 -DTNE two O 2− co-ordinating counter ions and one acetate co-ordinating counter ion are preferred.
[0034] It is preferred that the transition metal catalyst salt is present in a buffer system that maintains the solution in the pH range 2 to 7, and preferably in the pH range 4 to 6. The buffer systems is preferably phosphate or carboxylate containing buffers, e.g., acetate, benzoate, citrate. The buffer system most preferably keeps the transition metal catalyst salt in the range pH 4.5 to 5.5.
[0035] The catalyst solution may also be provided in a reduced volume form such that it is in a concentrate, solid or slurry which is then dispatched to its place of use. Removal of solvent is preferably done by reduced pressure rather than the elevation of temperature. Preferably the solution, solid or slurry is stored over an inert atmosphere, e.g., nitrogen or argon, with little or no headspace at 4° C. For storage purposes a preformed transition metal catalyst salt concentration range of 0.1 to 10% is desirable, more desirable is between 0.5 and 8%, and most desirable is between 0.5 and 2%. The concentrate or solid or solid most preferably has the pH means as described above before reduction of water volume.
[0036] In the bleaching process it is preferred that the substrate is contacted with between from 0.1 to 100 micromolar of the preformed transition metal catalyst and from 5 to 1500 mM of hydrogen peroxide.
[0037] Preferably the preformed transition metal catalyst salt and hydrogen peroxide are mixed just before introduction to the substrate.
Experimental
[0038] Examples on the syntheses of Mn 2 O 3 (Me 3 -TACN) 2 complexes with different anions are provided. Synthesis of the Mn 2 O 3 (Me 3 -TACN) 2 PF 6 salt is disclosed in U.S. Pat. No. 5,153,161, U.S. Pat. No. 5,256,779, and U.S. Pat. No. 5,274,147. The solubility of the Mn 2 O 3 (Me 3 -TACN) 2 PF 6 salt in water at 20° C. is 1.08% (w/w).
Preparation of Aqueous Solution of [Mn 2 O 3 (Me 3 -TACN) 2 ].(Cl) 2
[0039] To 10 mmol (1.71 gram Me 3 -TACN in 10 ml water was added 10 mmol (1.98 gram) solid MnCl 2 .4H 2 O while stirring under nitrogen flow. The mixture turned white/bluish. After 5 minutes stirring a freshly prepared mixture of 10 ml 1 M hydrogen peroxide and 2 ml of 5 M (20%) NaOH was added drop-wise over 5 minutes. The mixture turned immediately dark brown/red. At the end of the addition some gas evolution was observed. After completion of the addition the nitrogen flow was stopped and the stirring was continued for 5 minutes and pH was set with to neutral/acidic (pH 5 paper) with 1 M hydrochloric acid. The mixture was filtered through G4 glass frit, washed with water and the collected red filtrate and wash diluted to 50.00 ml in a graduated flask. From this solution a 1000× dilution was made and from the absorbtion in the UV/Vis spectrum at 244, 278, 313, 389 and 483 nm the concentration in the stock was calculated and the yield (based on extinction of the PF 6 analogue in water) Extinction of 1000× diluted sample gave
[0000]
244 nm
1.692
278 nm
1.619
313 nm
1.058
389 nm
0.108
485 nm
0.044
[0040] Calculated yield 91%, solution contains 5.2% (on weight basis) of the catalyst.
Preparation of Aqueous Solution of [of [Mn 2 O 3 (Me 3 -TACN) 2 ].(OAc) 2
[0041] To 10 mmol (1.71 gram Me 3 -TACN in 10 ml water was added 10 mmol (2.47 gram) solid MnCl 2 .4H 2 O while stirring under nitrogen flow. The mixture turned to a bluish solution. After 5 minutes stirring a freshly prepared mixture of 10 ml 1 M hydrogen peroxide and 2 ml of 5 M (20%) NaOH was added drop-wise over 5 minutes. The mixture turned immediately dark brown/red. At the end of the addition some gas evolution was observed. After completion of the addition the nitrogen flow was stopped and the stirring was continued for 5 minutes and pH was set with to neutral/acidic (pH 5 paper) with 1 M acetic acid. The mixture was filtered through a G4 glass frit, washed with water and the collected red filtrate and wash diluted to 50.00 ml in a graduated flask. From this solution a 1000× dilution was made and from the absorption in the UV/Vis spectrum at 244, 278, 313, 389 and 483 nm the concentration in the stock was calculated and the yield (based on extinction of the PF 6 analogue in water)
[0000]
244 nm
1.689
278 nm
1.626
313 nm
1.074
389 nm
0.124
485 nm
0.051
[0042] Calculated yield 88%; solution contains 5.2% (on weight basis) of the catalyst.
Preparation of Aqueous Solution of [Mn 2 O 3 (Me 3 -TACN) 2 ].SO 4
[0043] To 10 mmol (1.7 gram Me 3 -TACN in 10 ml water was added 10 mmol (1.98 gram) solid MnCl 2 .4H 2 O while stirring under nitrogen flow. The mixture turned to a white suspension. After 5 minutes stirring a freshly prepared mixture of 10 ml 1 M hydrogen peroxide and 2 ml of 5 M (20%) NaOH was added drop-wise over 5 minutes. The mixture turned immediately dark brown/red. At the end of the addition some gas evolution was observed. After completion of the addition the nitrogen flow was stopped and the stirring was continued for 5 minutes and pH was set with to neutral/acidic (pH 5 paper) with 1 M sulphuric acid. The mixture was filtered through a G4 glass frit, washed with water and the collected red filtrate and wash diluted to 50.00 ml in a graduated flask. From this solution a 1000× dilution was made and from the absorption in the UV/Vis spectrum at 244, 278, 313, 389 and 483 nm the concentration in the stock was calculated and the yield (based on extinction of PF 6 analogue in water)
[0000]
244 nm
1.648
278 nm
1.572
313 nm
1.022
389 nm
0.103
485 nm
0.042
[0044] Calculated yield 98%; solution contains 5.2% (on weight basis) of the catalyst.
Stability Experiments
[0045] Stability of aqueous solutions of chloride, sulphate and acetate salts are provided. Solutions of the bleach catalyst with chloride, sulphate and acetate anion were brought to pH 2, 3, 4 and 5 by hydrochloric acid, sulphuric acid and acetic acid respectively. For the acetate this could only give pH 5. For the lower pH values sulphuric acid was used in the case of acetate. The solutions were kept at 37° C. and after 2 weeks the stability was monitored from the absorptions in the UV/Vis spectra of 1000× diluted solutions.
[0000]
2 week results at 37° C.
pH 2
pH 3
pH 4
pH 5
Chloride
% (UV/Vis)
100
100
97
94
(Precipitate is formed at all pH's)
Acetate
% (UV/Vis)
87
91
93
95
(No precipitate is formed)
Sulphate
% (UV/Vis)
78
96
94
98
(Precipitate only at pH = 5)
[0046] For the two weeks results it is clear within experimental error (ca 5%) at pH 3 and higher no instability issue occurs.
[0047] Softwood chemical mill pulp obtained after the D0 bleaching stage (abbreviated as softwood D0 pulp) was used. The bleaching experiments were conducted on small scale in 100 ml vessels using the pulps at 5% consistency (i.e., 5% oven dry wood pulp; 95% aqueous bleaching liquor). The mixture contained 2.5 microM of the catalyst (as chloride, sulfate, acetate and PF 6 salts—see Table), 1 kg/t of MgSO 4 , 8 kg/t of NaOH and 10 kg/t of H 2 O 2 (kg/t: kg chemicals per ton oven dry pulp). The mixture was manually stirred to ensure good distribution of the bleaching chemicals. Then the vessel was placed in a water bath and stirred regularly at 50° C. for 1 h. All experiments were carried out at least 6 times. As a reference the experiment was conducted without catalyst. The dosages and exact reaction conditions are given in the sections below. After the allocated bleaching times the pulp batches were removed from the vessels, filtered using a Buchner funnel, and washed with 100 ml of water. From the resultant samples of bleached pulp 4×4 cm discs were made having a flat surface on one side. The softwood D0 pulp samples were dried using a L&W Rapid Dryer (Lorentzen and Wetter) at 90° C. for 20 minutes. Whiteness of the bleached pulps was determined using L, a*, b* values as defined by CIE (Commission Internationale de l'Eclairage) of the dried pad was measured using a Minolta spectrophotometer.
[0048] Results (all whiteness values show a standard deviation of 0.3 points.
[0000]
Complex
Whiteness
[Mn 2 O 3 (Me 3 —TACN) 2 ]•(PF 6 ) 2
84.4
comparative example
[Mn 2 O 3 (Me 3 —TACN) 2 ]•Cl 2
84.3
[Mn 2 O 3 (Me 3 —TACN) 2 ]•(OAc) 2
84.0
[Mn 2 O 3 (Me 3 —TACN) 2 ]•SO 4
84.1
Blank (only H 2 O 2 )
77.0
[0049] The data presented in the table show clearly that the bleaching effect is the same for all different catalyst-salt complexes.
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The present invention concerns bleaching of substrates with an aqueous solution of a water soluble salt of a preformed transition metal catalyst together with hydrogen peroxide.
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RELATED APPLICATIONS
[0001] This application is a continuation of International Application PCT/EP2013/067404 filed on Aug. 21, 2013 claiming priority from German patent application DE 10 2012 107 729.0 filed on Aug. 22, 2012, both of which are incorporated in their entirety by this reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a grinding device, in particular a vertical mill for grinding a grinding material, the grinding device including
[0003] a) at least two grinding elements that are movable relative to one another, wherein the two grinding elements together form at least one grinding portion in which the grinding material is grindable by the two grinding elements; and
[0004] b) at least one contact pressure device including at least one hydraulic cylinder including a cylinder operating chamber and at least one gas spring including a spring operating chamber, wherein the cylinder operating chamber and the spring operating chamber are flow connected with one another,
[0005] wherein a contact force is impartible upon at least one of the grinding elements by the at least one contact pressure device and the grinding elements are pressable onto one another by the contact force.
[0006] The term “grinding device” according to the instant application only includes grinding devices which are to be used in production processes. In particular grinding devices shall not be included which are only used for experimental and research and development purposes.
[0007] The term grinding element can relate to elements that actively impact the grinding material, for example actively driven rolling cylinders of a roller assembly and also passive and optionally stationary elements which are for example only used as a base for the grinding material and are thus used as an opposite part for an additional grinding element that actively imparts compression and/or shear forces. In any case a relative movement of at least two grinding elements has to be performed in order to achieve a grinding result.
[0008] With respect to a “flow connection” of the cylinder operating chamber with the spring operating chamber it is irrelevant as a matter of principle whether this connection is only formed by a two dimensional flow cross section, a connecting element, for example configured as a tubular conduit or is even formed by a plurality of different connecting elements.
[0009] The designation cylinder operating chamber designates a space within a hydraulic cylinder that is filled with a hydraulic fluid. It is a space in which a piston of the hydraulic cylinder is typically movable.
[0010] The “spring operating chamber” designates an entire space that is provided in an interior of the gas spring which is typically partly filled with a hydraulic fluid and which furthermore includes a gas cushion of the gas spring. Depending on a condition of the gas spring, accordingly the spring operating chamber can be filled in various portions with the hydraulic fluid and the gas of the gas cushion.
BACKGROUND OF THE INVENTION
[0011] Grinding devices of the general type described supra have been known for quite a while and are used in a plurality of applications. Exemplary embodiments are a so called roller mill and a so called vertical mill.
[0012] A roller mill typically includes two horizontal rolling cylinders which rotate opposite to one another, wherein both rolling cylinders have a minimum distance from one another or are in contact with one another at a knuckle where they form a grinding portion. The material to be ground or grinding material is introduced from a top side of the grinding portion between the two roller cylinders, wherein the individual particles of the grinding material stream pass through the grinding portion and are ground. Grinding devices of this type are used for example for grinding grain. An exemplary embodiment can be derived among others from WO 2009/067828 A1.
[0013] Vertical mills, however, are mills in which the grinding material is placed onto a horizontally arranged grinding table which rotates about a vertically oriented axis. In an outer circumferential edge portion of the grinding table in which the grinding material is collected based on the impacting centrifugal forces, typically plural so called roller mills are arranged whose rolling elements are formed by vertically standing rollers, whose rotation axis is horizontally oriented. The grinding portion in this type of mills is between a respective bottom side of the roller and the grinding table wherein due to the rotation of the grinding table about the vertical axis the grinding material is continuously moved along under the roller. Thus, the roller is pressed in a direction towards the grinding table, wherein the weight of the roller and also external pressing forces that are applied by the contact pressure device become effective. Under this pressure that is imparted by the roller onto the grinding material the grinding material is ground. Vertical mills of this type are typically used in the concrete industry. An exemplary embodiment can be derived among others from DE 10 2008 046 921 A1.
[0014] In particular the latter vertical mills that are known in the art have a basic problem in that they tend to enter an instable vibration condition which is commonly referred to as “rumbling”. In this condition the grinding device is vibrating which causes the roller and the grinding table to move relative to one another in a vertical direction, this means the roller is at least lifted by the grinding bed formed by the grinding material and can even lift off and subsequently presses or impacts on the grinding bed again. Here dynamic forces in an order or magnitude of several mega Newton [MN] can be at work so that the vertical mill can be damaged quite easily. For example a roller jacket which circumferentially envelops the roller is subject to a very high load in this instable vibration condition.
[0015] During operation of such grinding devices accordingly there is a long felt need to avoid these load conditions. Therefore monitoring systems are typically installed which detect particular operating parameters of the mill which eventually shall be used for drawing reverse conclusions with respect to a critical load. As a result there is the problem that shut downs and thus economically disadvantageous idle times of the mill occur due to anticipation of an impending resonance. Furthermore it happens from time to time that the described “rumbling” of the mill occurs in spite of these monitoring strategies.
[0016] The recited DE 10 2008 046 921 A1 relates among other things to this problem and attempts to monitor the grinding device so that critical load conditions are detected reliably and early, wherein the dynamic forces impacting the rollers shall be detected in particular frequency ranges and a shutdown of the entire grinding device shall be performed when reaching a threshold value.
[0017] In another document, EP 2 408 565 B1, the problem of rumbling mills is also discussed. The document describes a vertical mill whose contact pressure device is configured as an “open system”. This means that the contact pressure device which is formed by the at least one hydraulic cylinder and the at least one gas spring additionally includes at least one hydraulic pump through which an oil pressure in the at least one hydraulic cylinder and/or the at least one gas spring can be continuously adapted. In particular EP 2 408 565 B1 described that the effect of the hydraulic pump can load a lower pressure chamber of the hydraulic cylinder with pressure which causes the corresponding roller mill to “lift off”, this means that at least one contact pressure of the roller mill is reduced, optionally even a contact between the roller mill and the grinding bed is completely lost. This shall help to quiet the resonating mill system.
[0018] A disadvantage of the latter system is on the one hand side the complexity of the open pressure system which requires operating a hydraulic pump. On the other hand side the disclosed device as such is not free from disadvantageous vibration conditions (“rumbling”) but only provides a system which shall resolve the rumbling in a particularly simple manner should it occur.
[0019] Regardless, EP 2 408 565 B1 also provides a prevention strategy with regard to rumbling wherein the prevention strategy is based on a pressure adaptation of the rolling mills based on the effect of the hydraulic pump, wherein a pressure adaptation is used in the opposing pressure chambers of the hydraulic cylinders. This control system, however, is complex and slow since a pressure buildup by the hydraulic pump as a counter measure against a critical resonance that builds up takes a rather long time period, thus an entry of the mill system into resonance probably cannot be prevented in a timely manner.
[0020] Therefore a system which reliably prevents the risk of rumbling is not known in the art at all.
BRIEF SUMMARY OF THE INVENTION
[0021] Thus, it is an object of the instant invention to provide a grinding device which is not prone to enter the described instable vibration condition recited supra.
[0022] The technical task is accomplished improving upon a grinding device recited supra and providing grinding device, in particular a vertical mill for grinding a grinding material, the grinding device including at least two grinding elements that are movable relative to one another, wherein the two grinding elements together form at least one grinding portion in which the grinding material is grindable by the two grinding elements; and at least one contact pressure device including at least one hydraulic cylinder including a cylinder operating chamber and at least one gas spring including a spring operating chamber, wherein the cylinder operating chamber and the spring operating chamber are flow connected with one another, wherein a contact force is impartible upon at least one of the grinding elements by the at least one contact pressure device and the grinding elements are pressable onto one another by the contact force, wherein a smallest flowable cross-sectional surface between the cylinder operating chamber and the spring operating chamber amounts to at least 10% of a cross-sectional surface of the cylinder operating chamber and/or a connecting section extending between a first transitional cross-section of a connecting component communicating with the cylinder operating chamber, and a second transitional cross-section of the connecting component communicating with the spring operating chamber; wherein the connecting section has a maximum length of 100 cm.
[0023] The smallest cross sectional surface between the cylinder operating chamber and the spring operating chamber is thus always the sum of the cross sectional surfaces connected in parallel which are available to the hydraulic fluid for flowing from the cylinder operating chamber into the spring operating chamber. In case a single spring operating chamber with ten respective individual conduits connected in parallel in the form of tubular conduits which respectively have a constant cross sectional surface of 5 cm 2 are connected to the cylinder operating chamber the “smallest” cross sectional surface according the instant application is computed as A=10*5=50 cm 2 , since this is actually the smallest cross sectional surface which is available to the hydraulic fluid to flow into the spring operating chamber. Analogously individual cross sectional surfaces of individual connecting elements between a cylinder operating chamber and plural spring operating chambers add up in case the gas springs are connected in parallel to the cylinder operating chamber.
[0024] The present invention is based on the finding that the resonance problem (rumbling) of the known grinding device is caused by a stiffening of the entire grinding device. It was further found that this stiffening is substantially caused by a stiffening of the contact pressure device which is caused in particular by the fact that the gas spring connected at the hydraulic cylinder is no longer effective anymore in prior art grinding devices in the range of high frequency vibrations to which grinding devices are typically subjected. This means that hydraulic fluid that is provided in the hydraulic cylinder cannot flow over into the gas spring. The gas spring is used as a matter of principle to provide an expansion chamber for the hydraulic fluid that is arranged in the cylinder operating chamber, wherein the hydraulic fluid can flow into the compensation chamber as soon as a piston of the hydraulic cylinder is displaced.
[0025] The underlying problem is subsequently discussed with reference to a vertical mill configured as a roller mill.
[0026] A piston of a hydraulic cylinder in a roller mill according to the invention is typically directly connected with a bearing axis of the roller mill and substantially provides the contact pressure for the roller which forms a grinding element herein and impacts the grinding material. When the roller of the roller mill is deflected in a vertical direction which continuously occurs when the grinding material is rolled over the bearing axis of the roller of the roller mill rises together with the roller and consequently also the piston of the hydraulic cylinder rises which piston is thus moved in the hydraulic cylinder. In the course of this movement the hydraulic fluid is at least partially displaced into the gas spring connected to the cylinder operating chamber or it is displaced into the spring operating chamber, wherein typically hydraulic fluid is permanently located in the spring operating chamber of the gas spring and in a connection cross section or in a connection component between the cylinder and the spring operating chamber. Introducing additional hydraulic fluid into the gas spring compresses a gas cushion in the spring operating chamber which gas cushion is typically formed from nitrogen and an additional reset force is created on top of the preload that is already applied. This has the effect that the hydraulic fluid tends to flow back into the cylinder operating chamber, wherein the piston of the hydraulic cylinder and consequently also the roller are pressed back in vertical downward direction onto the grinding bed.
[0027] When a sudden and strong displacement of the roller of the vertical mill occurs during the grinding process, for example when rolling over a particularly large particle in the grinding material a sudden displacement of the piston in the hydraulic cylinder and consequently an acceleration of the hydraulic fluid in the cylinder operating chamber occurs as described.
[0028] Due to this acceleration of the hydraulic fluid in the cylinder operating chamber analogously also the hydraulic fluid has to be accelerated and displaced which is arranged in the connection cross section between the cylinder operating chamber and in the spring operating chamber. In the art this connection cross section which is typically defined by a tubular connection element has a much smaller cross sectional surface than the cylinder operating chamber (c.f. for example FIG. 1 of DE 10 2008 046 921 A1). This “constriction” of a flowable cross section (leap from cross section of the cylinder operating chamber to the connection element or the connection cross section) which is imposed upon the hydraulic fluid has the effect that a higher flow velocity of the hydraulic fluid has to be provided in the connection cross section, wherein the increase in flow velocity is inverse proportional to the cross section contraction. In the present case due to the high occurring vibration frequency the increase in flow velocity has the effect that the hydraulic fluid in the connection cross section has to be accelerated accordingly fast. This acceleration applied to the hydraulic fluid in the connection cross section is therefore many times higher than in the cylinder operating chamber.
[0029] Large forces are required to cause this acceleration. However, the prior art only provides a rather small connection cross section so that the hydrostatic pressure of the hydraulic fluid has only a small “effective surface”, namely only the connection cross section. This has the effect that the hydraulic fluid arranged in the connection cross section is not accelerated and consequently not moved; thus the spring operating chamber cannot be activated as a compensation chamber for the hydraulic fluid at all. When the roller of the grinding device is displaced this displacement cannot be compensated with a movement of the piston since the piston remains in its original position for the moment and does not permit any vertical movement of the bearing axis of the vertical mill. Instead, the entire foundation may be deformed on which the vertical mill is based, wherein the extremely high stiffness of the entire system eventually causes the extreme forces recited supra due to the dislocation of the roller wherein the forces can eventually cause the damages that occur in the prior art.
[0030] The features according to the invention which can be implemented as alternatives or advantageously together help to prevent this very disadvantageous effect of the known grinding devices.
[0031] Thus, it is possible on the one hand side to set the minimal or smallest cross sectional value to a minimum value which shall be at least 10% of the cross sectional surface of the operating cylinder. This predetermination of a “minimum size” of the smallest cross sectional surface assures that the ratio of accelerations between the cylinder operating chamber and the connection cross section is limited to a maximum value, thus the force required to accelerate the hydraulic fluid in the connection cross section is limited in upward direction. This helps to prevent that the resistance of the hydraulic fluid embodied as inertia increases in the smallest cross section surface beyond a maximum value which stiffens the entire grinding device. This solution is particularly advantageous.
[0032] On the other hand side it is also possible according to the invention alternatively or also additionally although rather complicated to limit the connection distance according to the description provided supra to the recited maximum length. This is provided in view of the fact that a short connection distance causes a rather small volume of hydraulic fluid in the connection cross section. In analogy to the volume of hydraulic fluid thus consequently also the mass provided in the connection cross section is limited to a maximum amount. The force [F] which is required to accelerate a mass [m] with a particular acceleration is determined by the equation F=m*a. This means that the required force to accelerate the hydraulic fluid can be applied even when the cross sectional ratio of the cross sectional surface of the cylinder operating chamber to the smallest cross sectional surface between the cylinder operating chamber and the spring operating chamber should be below the recited 10%. Conductor lengths illustrated in the prior art substantially exceed the claimed values and show that the problems discussed supra are not understood in the prior art.
[0033] Advantageously the recited minimum ratio of the cross sectional surface according to the invention and the maximum connection distance between cylinder operating chamber and spring operating chamber are combined.
[0034] A blockade or deactivation of the gas spring as it occurs according to the prior art is permanently prevented by the grinding device according to the invention according to the description provided supra and thus the object is achieved.
[0035] In a particularly advantageous embodiment of the grinding device according to the invention the smallest flowable cross sectional surface between the cylinder operating chamber and the spring operating chamber is at least 20%, advantageously at least 20%, further advantageously at least 80% of a cross sectional surface of the cylinder operating chamber. These additional larger ratios are particularly advantageous for an efficient operation of the grinding device according to the invention. In particular an inertial force occurring at the connection cross section can be further reduced which can lead to a far reaching slimming of the entire grinding device in particular to a reduction of its foundation mass.
[0036] In another advantageous embodiment of the device according to the invention it is proposed to limit the connection distance to a maximum length of 60 cm, advantageously at the most 30 cm, further advantageously at the most 10 cm. In analogy to the preceding discussion this causes an additional reduction of the inertial forces and thus a substantial size and weight reduction of the entire grinding device.
[0037] In another advantageous embodiment of the grinding device according to the invention it is proposed to configure the at least one gas spring as a bladder reservoir. Reservoirs of this type are particularly easily available and can be installed in retrofit solutions for already existing grinding devices with reasonable complexity.
[0038] Particularly advantageously a plurality of gas springs that is connected to the hydraulic cylinder in parallel is provided in this context, wherein the parallel connected connection cross sections between the cylinder operating chamber and the individual operating chambers of the individual gas springs are added up to form a cross sectional surface according to claim 1 which is available to the hydraulic fluid and based on which the ratio according to the characterizing feature of claim 1 is computed.
[0039] In a particularly advantageous embodiment of the grinding device according to the invention a damping device is provided by which a flow velocity of the hydraulic fluid flowing between the cylinder operating chamber and the spring operating chamber is reducible, advantageously a degree of damping of the damping device for different flow directions of the hydraulic fluid has different magnitudes, wherein further advantageously the degree of damping for a flow of the hydraulic fluid in a direction oriented away from the piston of the hydraulic cylinder is greater than for a flow of the hydraulic fluid in reverse direction. Providing a damping device is advantageous as a matter of principle since an excitation of the roller caused by the grinding bed or the grinding material and thus an excitation of the hydraulic fluid are dampened and disadvantageous vibrations and disadvantageous reset forces can be prevented.
[0040] Configuring a tension stage and a compression stage of the damper differently is advantageous in this context, thus a different embodiment of the degree of damping achieved by the damping device which should advantageously be less for a lifting of the roller, thus a flow direction of the hydraulic fluid in a direction of the spring operating chamber, than in reverse direction. This way it is rather “easy” to lift the roller off from the grinding bed, however braking is performed when the roller is returned so that an unnecessary hard impact of the roller on the grinding bed is prevented. This is particularly helpful to keep wear of the roller of the vertical mill as small as possible and in order to not deform the grinding bed unnecessarily as it happens in the prior art (“wash board”).
[0041] In order to achieve maximum flexibility of the grinding device it is furthermore particularly advantageous when the degree of damping of the damping device is variable as a function of the flow direction of the hydraulic fluid. This way it is possible for an operator to configure the damping device for example for different grinding materials or different consistencies of the same grinding material.
[0042] In a particularly advantageous embodiment of the damper device, the damper device is formed by a throttle plate including pass through openings wherein the damping device advantageously also includes at least one blocking device that is moveable relative to the throttle plate and through which the pass through openings of the throttle plate are at least partially closeable. A damper device of this type can be produced in a particularly simple manner and is adjustable in a particularly simple manner through the blocking device.
[0043] In another particularly advantageous embodiment of the grinding device according to the invention the hydraulic cylinder and the gas spring are configured as an integrated contact pressure device, wherein the cylinder operating chamber and the spring operating chamber transition into one another seamlessly, wherein in particular the hydraulic fluid is arranged between a piston of the contact pressure device and a gas cushion of the contact pressure device. In this embodiment the cylinder operating chamber and the spring operating chamber geometrically speaking are the same operating chamber, wherein functionally speaking a sub division into cylinder operating chamber and spring operating chamber in the sense of the preamble of claim 1 is still possible. The smallest cross sectional surface in the sense of claim 1 is formed in this embodiment by the cross section of the cylinder operating chamber or the spring operating chamber itself so that a ratio of the smallest cross sectional surface to the cross sectional surface of the cylinder operating chamber is 100% in this case.
[0044] This suggested integrated embodiment is implementable in a particularly simple manner and is recommended accordingly for grinding devices to be newly constructed.
[0045] Furthermore an embodiment of this type of the grinding device according to the invention is particularly advantageous in which the contact pressure force that is applicable by the contact pressure device is variable. This facilitates maximum adaptability of the grinding device for the respective grinding material.
[0046] It is furthermore particularly advantageous when the at least one hydraulic cylinder and the at least one gas spring form a closed hydraulic system. Thus, a “closed hydraulic system” is a system where a pressure (“preload”) externally applied from an outside to the system including the hydraulic cylinder and the gas spring is kept constant in that the system is closed. An option for the hydraulic fluid or another component provided in the system to escape is as impossible as adding such component. In particular a closed hydraulic system does not include any hydraulic pump that is permanently connected with the hydraulic system through which a pressure in the contact pressure device is continuously adapted, thus continuously increased or reduced. Though a hydraulic pump is typically provided in order to perform a pressure correction as required. The hydraulic pump, however, is decoupled from the hydraulic system which is typically achieved by locked pressure conduits which are only opened when required.
[0047] In another advantageous embodiment of the grinding device according to the invention the at least one hydraulic cylinder includes at least one cylinder operating chamber. A hydraulic cylinder of this type is comparatively simple and performs all necessary functions as an element of the contact pressure device. In particular it is not necessary in the grinding device according to the invention to provide a “lower pressure chamber” below the piston of the hydraulic cylinder through which lower pressure chamber the piston can be lifted through an externally applied pumping power in the hydraulic cylinder which would simultaneously lift the grinding element configured as the roller. In the prior art similar configurations are used to mitigate the risk of reaching critical resonance and to lift the roller from its grinding bed when necessary. Since the grinding device according to the invention does not have an inherent risk of reaching resonance any more a hydraulic cylinder with two cylinder operating chambers is not necessary.
BRIEF DESCRIPTION OF THE DRAWINGS
[0048] The invention is now described in more detail based on embodiments with reference to drawing figures, wherein:
[0049] FIG, 1 illustrates a known grinding device;
[0050] FIG. 2 illustrates a first grinding device according to the invention with a plurality of individual gas springs;
[0051] FIG. 3 illustrates a detail of a contact pressure device of the grinding device according to FIG. 2 ;
[0052] FIG. 4 illustrates another grinding device according to the invention with a plurality of individual gas springs configured as bladder reservoirs;
[0053] FIG. 5 illustrates a detail of a contact pressure device of the grinding device according to FIG. 4 ;
[0054] FIG. 6 illustrates another grinding device according to the invention with an integral embodiment of a cylinder operating chamber and a spring operating chamber; and
[0055] FIG. 7 illustrates a sectional view through a contact pressure dev e of the grinding device according to FIG. 6 .
DETAILED DESCRIPTION OF THE INVENTION
[0056] A first embodiment which is illustrated in FIG. 1 illustrates a known grinding device 100 wherein the illustration according to FIG. 1 is reduced to essential components of the grinding device 100 . The grinding device 100 illustrated herein is a so called vertical mill. The vertical mill includes a total of 5 grinding elements 2 , 3 wherein four grinding elements 2 interact as rollers 4 with the grinding elements 3 configured as a grinding plate 5 . Grinding material which is not illustrated herein is arranged on the grinding plate 5 .
[0057] The grinding plate 5 is driven by a drive device that is not illustrated so that it rotates about a vertical axis. The movement of the grinding plate 5 moves the grinding material arranged thereon, wherein the grinding material is moved along under the rollers 4 wherein the rollers are being dragged, this means they rotate about a horizontal rotation axis 6 solely due to the rotation of the grinding plate 5 . There is no active drive for the rollers 4 , but it can be easily implemented.
[0058] The rollers 4 are preloaded in a vertical direction by a contact pressure device 101 , this means they are pressed by the contact pressure device 101 in a direction towards the grinding plate 5 or towards a grinding bed formed from the grinding material. Under a pressure of the contact pressure device 101 and under a weight of the rollers 4 the grinding material is ground on the grinding plate 5 , wherein the rollers and the grinding plate, thus the grinding elements 2 , 3 move relative to one another.
[0059] The contact pressure device 101 includes a hydraulic cylinder 8 which is not visible in FIG. 1 and a gas spring 9 . Both components are flow connected by a flow connector 102 which is provided as a tubular conduit. A spring operating chamber of the gas spring 9 includes a gas cushion which is formed from nitrogen. A cylinder operating chamber of the hydraulic cylinder 8 , the connector 102 and a portion of the spring operating chamber of the gas spring 9 arranged outside of the gas cushion are filled with a hydraulic fluid.
[0060] When a vertical displacement of one of the roller 4 occurs during operation of the grinding device 100 a piston of the hydraulic cylinder 8 of the contact pressure device 101 which piston is connected with a bearing axle 11 of the roller 4 is moved in a vertical direction. Thus, the piston displaces the hydraulic fluid provided in the cylinder operating chamber wherein the hydraulic fluid subsequently flows at least partially through the connector 102 into the spring operating chamber of the gas spring 9 . Thus, the gas cushion in the gas spring 9 is compressed and an additional reset force is generated on top of the preload recited supra wherein the reset force is stored as potential energy in the gas when the gas cushion is compressed. As soon as the roller 4 can move back again towards the grinding bed or the grinding plate 5 , the hydraulic fluid is pressed from the spring operating chamber of the gas spring back into the cylinder operating chamber of the hydraulic cylinder 8 and the piston of the hydraulic cylinder 8 is accordingly moved back into its prior position.
[0061] A smallest flowable cross sectional surface of the connection component 102 of the grinding device 100 is particularly small relative to a cross sectional surface of the cylinder operating chamber and only amounts to a few percent of the cylinder operating chamber, thus approximately 2%. This typical embodiment that is known in the art causes the problems recited supra in detail.
[0062] Furthermore a connection distance which extends between the cylinder operating chamber of the hydraulic cylinder 8 and the spring operating chamber of the gas spring 9 within the connection component 102 is approximately 200 cm long in the illustrated embodiment. Thus, a total amount of hydraulic fluid is accumulated in the connecting component 102 so that a substantial force would be required for an instantaneous acceleration of this hydraulic fluid which force cannot be applied due to the very small available cross sectional surface of the connecting component 102 . Consequently the connecting component 102 that is known in the art acts as a “plug” which almost prevents a flow of the hydraulic fluid from the hydraulic cylinder 8 to the gas spring 9 in a range of high load frequencies.
[0063] This problem is solved by a first embodiment of a grinding device 1 according to the invention which is illustrated in FIG. 2 . The grinding device 1 illustrated herein includes a contact pressure device 7 which is mounted at a so called force frame 12 through which the forces caused by the contact pressure device 7 are reacted in a foundation 22 . Like in the grinding device 100 the piston of the hydraulic cylinder 8 is mounted on the bearing axle 11 of the roller 4 in order to push down the roller 4 by the bearing axle 11 , thus to press it onto the grinding bed.
[0064] In the illustrated embodiment the hydraulic cylinder 8 extends with a constant cross section above the force frame 12 . At each hydraulic cylinder 8 a total of six gas springs 8 are connected which are respectively flow connected with a proper connector 10 with the cylinder operating chamber of the hydraulic cylinder 8 . The connectors 10 are easily recognizable in a detailed representation according to FIG. 3 . The individual connectors 10 are substantially similar to the connector 102 of the grinding device 100 with respect to their smallest cross sectional surface. However, contrary to the grinding device 100 known in the art plural connectors 10 are connected in parallel so that the hydraulic fluid which is displaced from the hydraulic cylinder 8 during a piston movement is overall provided with a cross sectional surface through which it can exit from the cylinder operating chamber, wherein the cross sectional surface corresponds to six times an individual cross sectional surface of each connecting component 10 . This way a surface ratio of the smallest cross section surface (equals six times the smallest cross section surface of the six individual connection components 10 ) between the cylinder operating chamber and the spring operating chamber relative to the cross sectional surface of the cylinder operating chamber of approximately 40% is provided in the illustrated embodiment.
[0065] This significant enlargement of the flowable cross section according to the invention resolves the previously described “plugging effect” or the stiffening effect of the connector.
[0066] In a detail of the contact pressure device 7 which is illustrated in FIG. 3 an individual hydraulic cylinder 8 , six connection components 10 connected therewith and a respectively associated gas spring 9 are visible particularly well. A cylinder operating chamber of the hydraulic cylinder 8 is completely filled with the hydraulic fluid so that the connection components 10 can be easily connected at an outer jacket 23 of the hydraulic cylinder 8 with an elevation offset. An illustrated “vertical” arrangement of the gas springs 9 in which the respective connection component is connected at the gas spring 9 at a bottom side of the respective gas spring 9 and the gas cushion is arranged in an upper section of the gas spring 9 , is particularly advantageous in order to prevent that the gas cushion is flow enveloped or enclosed by the hydraulic fluid as can be the case for a reverse arrangement of the connection component 10 and the gas cushion.
[0067] In another embodiment which is illustrated in FIG. 4 the gas springs 8 of a contact pressure device 7 ′ of a grinding device 1 ′ are formed by bladder accumulators 13 which are respectively individually connected analogously to the grinding device 1 illustrated in FIGS. 2 and 3 by a proper connecting component 10 ′ at the hydraulic cylinder 8 . In the illustrated embodiment a total of seven gas springs 9 or bladder accumulators 13 are provided. Bladder accumulators 13 are easily available in many shapes so that the grinding device 1 ′ is an embodiment that can be installed quickly and economically when modernizing existing grinding devices.
[0068] For illustration purposes FIG. 5 depicts a detail of the bladder accumulator 13 that is arranged at the cylinder operating chamber of the hydraulic cylinder 8 . The connection elements 10 ′ thus include a cross sectional surface which approximately corresponds to 60% of the cross sectional surface of the hydraulic cylinder 8 . Furthermore the connection components respectively include a throttle element.
[0069] Another embodiment which is illustrated in FIG. 6 includes an additional grinding device 1 ′ according to the invention whose contact pressure device 7 ′ differs from the contact pressure device of the remaining embodiments. The hydraulic cylinder 8 and the gas spring 9 of the contact pressure device 7 ″ are configured as an integral component, this means the cylinder operating chamber and the spring operating chamber transition into one another seamlessly while maintaining a constant cross section and are no longer discernably separated from one another. This means for the illustrated contact pressure device 7 ″ that the piston protrudes into the hydraulic cylinder 8 from the bearing axle 11 , thus from below, and that the piston is supported axially moveable in the hydraulic cylinder 8 . The hydraulic fluid typically a hydraulic oil is arranged on a side of the piston which is oriented away from the bearing axle 11 . In so far the configuration of the contact pressure device 7 ′ corresponds to the configuration of the contact pressure devices 7 and 101 .
[0070] However in the contact pressure device 7 ″ the gas spring 9 is not configured separately any longer but integrated directly at a “top side” of the hydraulic cylinder 8 which renders a discernable differentiation of the cylinder operating chamber and the contact pressure device 7 ″ impossible. Thus, the gas cushion associated with the gas spring 9 is arranged at a top side 14 of the contact pressure device 7 ″, wherein the gas cushion is preloaded. The hydraulic fluid directly contacts the gas cushion so that the cylinder operating chamber and the spring operating chamber are jointly arranged in a continuous space.
[0071] The variant of the grinding device 1 ″ illustrated in FIG. 6 is particularly advantageous. In particular according to the definition the ratio of the smallest cross sectional surface between the hydraulic cylinder 8 and the gas spring 9 relative to the cross sectional surface of the cylinder operating chamber is equal to one, whereas the connection distance between the cylinder operating chamber and the spring operating chamber according is equal to zero per definition. Thus, this embodiment includes the best possible combination of hydraulic cylinder 8 and gas spring 9 which is furthermore producible in a particularly simple and cost effective manner.
[0072] FIG. 7 eventually illustrates a detail of the contact pressure device 7 ″, wherein the contact pressure device 7 ″ is illustrated in a longitudinal sectional view. The hydraulic cylinder 8 is configured herein as so called “plunger cylinder”, wherein a plunger piston 24 is arranged in a lower portion of the contact pressure device 7 ″. A center portion 25 of the contact pressure device 7 ″ is filled with the hydraulic fluid wherein the center portion 25 is arranged in front of a portion 21 of the contact pressure device 7 that includes the gas cushion formed by nitrogen. The gas cushion is separated in a sealing manner by a separation piston 20 from the hydraulic fluid, wherein the separating piston 20 is supported in a “floating manner” in the contact pressure device 7 ″ so that it can move freely in an axial direction of the contact pressure device 7 ″.
[0073] A damping device 15 configured as a throttle plate 16 is particularly significant in this respect. The throttle plate 16 includes a plurality of pass through openings 17 which form a constriction of the flow cross section of the hydraulic fluid in the contact pressure device 7 ″. The damping device 15 is interpreted herein as a component that is arranged strictly for damping purposes and not a connecting component in the sense of the connecting components 10 and 10 ′ of the embodiments described supra.
[0074] An interpretation of this type of the illustrated damping device 15 , however, is still possible. Thus, in the sense of claim 1 the throttle plate 16 represents the connecting component between the cylinder operating chamber and the spring operating chamber, wherein the cylinder operating chamber is arranged on the side of the throttle plate 16 oriented towards the plunger piston 24 and the spring operating chamber is arranged accordingly on a top side of the throttle plate. The transition cross sections would be formed according to claim 1 by the transitions from the respective operating chambers (cylinder and spring operating chambers) to the pass through openings 17 , wherein the connection distance would correspond to a length, this means to an extension of the throttle plate 16 in an axial direction of the contact pressure device 7 ″ (thickness of the throttle plate 16 ). The throttle plate 16 has a thickness of 1 cm so that a risk of stiffening the contact pressure device 7 ′ as provided in the prior art is not provided due to the small masses that need to be accelerated.
[0075] The damping device 15 provides a flow resistance when the hydraulic fluid flows through the pass through openings 17 with the hydraulic fluid wherein the flow resistance is opposite to the flow direction and leads to a braking of the hydraulic fluid or to a reduction of its flow velocity. A resistance of the damping device 15 is thus proportional to the flow velocity of the hydraulic fluid.
[0076] The damping device 15 furthermore includes a blocking device 18 . The blocking device 18 is rotatable about a vertical longitudinal axis of the contact pressure device 7 ″ relative to the throttle plate 16 , wherein solid, herein triangular blocking elements 19 of the blocking device 18 are configured to move over the pass through openings 17 of the throttle plate 16 and thus close the throttle plate 16 . Simultaneously a free portion below the blocking elements 19 which is not visible in FIG. 7 is released in that a flow cross section between a top side and a bottom side of the damping device 15 is configured without installations. Consequently the damping device 15 is illustrated in the position shown in FIG. 7 in its maximum damping position since all free portions are closed and only portions are released in which the hydraulic fluid has to be “pressed” through the pass through openings 17 of the throttle plate 16 which creates the desired friction. Rotating the blocking device 18 can be used to flexibly adapt a level of damping of the damping device 15 .
REFERENCE NUMERALS AND DESIGNATIONS
[0077] 1 , 1 , 1 ′ grinding device
[0078] 2 grinding element
[0079] 3 grinding element
[0080] 4 roller
[0081] 5 grinding plate
[0082] 6 , rotation axis
[0083] 7 , 7 ′ contact pressure device
[0084] 8 hydraulic cylinder
[0085] 9 gas spring
[0086] 10 , 10 connecting component
[0087] 11 bearing axle
[0088] 12 load frame
[0089] 13 bladder accumulator
[0090] 14 top side
[0091] 15 damping device
[0092] 16 throttle plate
[0093] 17 pass through opening
[0094] 18 blocking device
[0095] 19 blocking element
[0096] 20 separating piston
[0097] 21 portion
[0098] 22 foundation
[0099] 23 jacket
[0100] 24 plunger piston
[0101] 25 jacket
[0102] 100 grinding device
[0103] 101 contact pressure device
[0104] 102 connecting component
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A grinding device, in particular a vertical mill for grinding a grinding material, the grinding device including at least two grinding elements that are movable relative to one another, wherein the two grinding elements together form at least one grinding portion in which the grinding material is grindable by the two grinding elements; and at least one contact pressure device including at least one hydraulic cylinder including a cylinder operating chamber and at least one gas spring including a spring operating chamber, wherein the cylinder operating chamber and the spring operating chamber are flow connected with one another, wherein a contact force is impartible upon at least one of the grinding elements by the at least one contact pressure device and the grinding elements are pressable onto one another by the contact force, wherein a smallest flowable cross-sectional surface between the cylinder operating chamber and the spring operating chamber amounts to at least 10% of a cross-sectional surface of the cylinder operating chamber and/or a connecting section extending between a first transitional cross-section of a connecting component communicating with the cylinder operating chamber, and a second transitional cross-section of the connecting component communicating with the spring operating chamber, wherein the connecting section has a maximum length of 100 cm.
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This application claims the benefit of 60/349,619 filed Jan. 22, 2002.
BACKGROUND
1. Field
The present invention relates to roofing clips and more particularly to such clips that are applied to secure metal roofing panels.
2. Prior Art
Typically, metal roofing panels are secured to roof using relatively small clips that are one to three inches long. Each clip is secured to the roof by means of several screws. The clips are positioned at regular intervals along a roofing panel at a spacing of 16 to 24 inches on center.
A typical clip 14 is shown in FIGS. 8A and 8B and the use and method of installation is described in U.S. Pat. No. 4,796,403. These clips that have a width of typically only 3 inches have worked reasonably well for years, but there are some problems that these clips present that have not previously been solved.
Among the problems are the following:
1. High spot up-lift loads can tear out a single clip. With the roofing panel being made less secure with one clip gone, the next clip is more easily torn out because it receives a greater load. The loss of clips continues until there is no support for the panel and it is blown away.
2. Roofing installers are often left to determine spacing between clips or even if a clip will be used in some locations. There is little in the prior art to force the installer to place clips at a preferred center to center spacing distance.
3. It is time consuming to install 15 individual clips along a 20 foot roofing panel. By installing all the clips, the roof's integrity is maintained, however, the cost is high because of the level of labor required to install the clips. If the spacing is decreased the cost goes down, but the integrity of the roof is compromised. These and other problems associated with prior art metal roof clips are addressed and solved by the present invention described in the following sections.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a perspective view of the continuous clip of the present invention using a first variation of an individual clip.
FIG. 2 is a front elevation view of the L bracket and an individual clip of the type shown in FIG. 1 .
FIG. 2A is a perspective view of second version of the individual clip used with the present invention.
FIG. 2B is a front elevation of the individual clip of the type shown in FIG. 2 A.
FIG. 2C is a plan view of a roof showing the location of the purlins, continuous clip and roof panels.
FIG. 3 is a front elevation view of a continuous clip used with a purlin.
FIG. 4 is a second version of a continuous clip made in accordance with the present invention.
FIG. 5 is a perspective view of the second version of the present invention as used with the individual clips used with snap lock panels.
FIG. 6A is a front elevation view of a clip and two panels which shows the position of two panels and the clip before they are bent to provide a sealed joint.
FIG. 6B shows the elements of FIG. 6A partially bent to 90° as a first step in producing a seal.
FIG. 6C shown the elements of FIG. 6B further bent to 180° to complete the seal.
FIG. 7 is a front elevation view of two panels and a clip which snaps together to make a seal.
FIG. 8A is a perspective view of a prior art individual clip.
FIG. 8B is a front elevation view of the clip of FIG. 8 A.
SUMMARY
It is an object of the present invention to provide a roofing clip that can be installed quickly.
It is an object of the present invention to provide a roofing clip that provides an increased up-lift load capability.
It is an object of the present invention to provide a roofing clip that provides strength to the roofing panels between purlins.
A continuous panel clip that extends typically ten feet in length rather than the usual prior art one to two inches, enabling the clip to span the distance between purlins and support roof panels over these distances. Shorter or longer lengths such as 12 inches to 20 feet or any length are possible for the continuous clip. The extended length of the continuous clip enables it to provide greater strength against uplift loads than that which was possible with the older short clips and this continuous clip can be installed more quickly than a series of the usual short clips commonly use to cover the same span.
The present invention includes a long “L” shaped bracket with attached individual, small clips spaced apart along the bracket at a uniform distance of typically 16 inches. The “L” bracket has two sections with one held parallel to the roof while the second section stands orthogonal to the first. The small clips are connected to the second section through slots placed in the second section. The slots allow for expansions and contraction of the roof under various environmental conditions as well under other loads placed on the roof. Attaching the long “L” shaped bracket securely holds all of the clips in place and insures that sufficient clips are present to properly secure the roof panels against up-lift loads.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a perspective view of a first form of a continuous clip 1 . This version of the continuous clip consists primarily of a long “L” bracket 2 which includes two sections, a mounting plate 2 A and a clip support plate 2 B, that is positioned orthogonally with respect to the mounting plate. The clip support plate includes a series of slots, such a slot 4 through which are installed a series of individual clips such as clip 3 .
The first individual clip 3 located to the left in this figure and the clip support plate 2 B are cut away to illustrate how an individual clip is bent up to provide a portion 3 A of the individual clip that hold this clip in the slot 4 . At the opposite end of the clip is a portion 3 B that is positioned vertically. Connected to and located above the portion 3 B is a portion 3 C which is positioned horizontally. The portions 3 B and 3 C are used to connect the clip to the seams of the roofing panels as will be shown and described in connection with FIGS. 6A through 6C .
The mounting plate 2 A includes a series of holes, such as hole 5 , distributed along the length of the mounting plate to permit mounting the “L” bracket to a substrate, such as a roof, by means of screws that are passed through these holes and screwed into the roof. The continuous clip is so named because it is typically ten feet long, whereas commonly used short, independent clips, such as the one shown in FIGS. 8A and 8B are only 2 to 3 inches long. The many individual clips used in the present invention with one “L” bracket are spaces 16 to 24 inches apart along the clip support plate, which is the same spacing commonly used to mount short independent clips along a roofing panel.
The individual clips of the present invention are used in newer installation systems to hold down roof panels in metal roofing systems. These clips avoid puncturing the roof which was required for mounting screws in older installation methods. The clips grip the edge of the panel and are themselves covered by the edge of the next adjacent panel. The method of connection to the panel is shown in FIGS. 3 , 4 , 6 and 7 and is described below.
The advantages of the continuous clip over a plurality of commonly used short clips are many and some are unexpectedly beneficial. First and foremost is the added strength provided by the continuous clip to up-lift loads. Where a small clip is used, it can be pulled out by a high spot level of up lift force, such as that produced by the high winds of a hurricane. Once one clip has been pulled out, the next clip in line holding a roofing panel received an even greater up-lift force because it is required to withstand the up-lift force for its own position on the roof panel as well as part of the up-lift force that was previously provided by the clip that has been pulled out. In addition, the panels tend to be picked up by the wind and act as a sail, greatly increasing the up-lift force where a clip has been lost. The result is a tearing out of one clip after another along a panel once one clip has been lost. Test results described below show the continuous clip to have unexpectedly good results in withstanding uplift loads, a very important factor in resisting hurricane force winds.
With the present invention, no individual clip is left only to its own mounting screws to survive. The entire “L” bracket is held down to the roof by a series of screws along the “L” bracket. No one clip can be pulled up. The entire “L” bracket with all its mounting screws would have to be moved at once in an upward direction against the holding force of all the screws. The result is a substantially greater resistance to up-lift forces is provided by the present invention. The clips are held securely by the continuous clip of the present and its many mounting screws.
Where the continuous clip is used with purlins, and the mounting screws or other mounting attachment means make a rigid connection between the bracket and the purlins, the bracket of the continuous clip prevents racking of the purlins because it forms a rigid box structure. This feature strengthens the roof and the building against uplift and other loads.
The bracket may be rigidly attached to the purlins by using two or more screws, welding, riveting, square pins or other rigid attachment means at each junction of the bracket and the purlins. This rigid attachment prevents rotation of the brackets with respect to the purlins and this prevents purlin roll.
When the purlins roll, they can be turned sideways where they may have no strength, allowing them to be bent up due to uplift wind loads. When this occurs, the roof may be blown away or fall inward. The rigid connection of the bracket of the present invention to the purlins totally prevents this type of failure.
The holes in the bracket used to accept the individual clips may be placed in the bracket so that individual clips will be located between purlins where the clips could not be placed when using short clips.
As few or many holes and clips may be used as necessary between purlins to sustain required up lift and other live loads.
A second advantage of the continuous clip is the speed with which it may be installed. Once a screw has been installed at both ends of the mounting plate, it holds itself in position while the remainder of the screws are installed. With the small prior art clips each and every clip has to be located and then held in position while two to three screws are installed.
Where the substrate is formed of spaced apart purlins, the continuous clip provides strength for the roofing panels between purlins. The continuous clips angle bracket provides strength against bending between the purlins and the individual clips hold down the roofing panels between the purlins where conventional small clips cannot be placed. The presence of the continuous clip bracket between purlins provides strength to the panels against both uplift and live loads that other clip systems cannot provide.
In addition, the continuous clip has greater strength than the conventional clips because heavier gauge steel is used for the continuous clip. The continuous clip typically uses 18 gauge steel as opposed to the 22 gauge typically used on conventional small clips. The gauge of the continuous clip can be varied as needed to suit a particular application.
The present invention was tested at the Hurricane Test Laboratory, Inc. on 09-22-02 with outstanding results. The following is an excerpt from the results of that test using the continuous clip of the present invention.
For this test, a load was applied in the form of suction on the upper surface of the roof panels. The load was applied in 20 psf increments until 135 psf was achieved, at which point no additional load could be applied to the sample. The flat of the roof panels had deflected and distorted to such a degree that it had bottomed-out on the framing of the test chamber. NOTE: The flat of the panels deflected approximately 15″ from its original shape without disengaging. The sample was thoroughly inspected. No failures were observed in the clip attachments of the continuous clip (of the present invention) to the purlin or to the attachment between the panels and the continuous clip at the standing seams of the panels.
FIG. 2C is a plan view of a roof 16 having a ridge end 16 A, and eave end 16 B, a first gable end 16 C and a second gable end 16 H. A first purlin 16 C located 5 feet below the roof ridge extends horizontally from the first gable and to the second gable and, while a second purlin 16 D, located 5 feet below the first purlin extends from the first gable and to the second gable end. Adjacent roof panels 16 F and 16 I extend vertically in this figure across and are supported by the purlins from the eave to the ridge. A seam 16 E extends vertically between and at the junction of panels 16 F and 16 I. Beneath this seam resting on and attached to the purlins is a continuous clip containing a plurality of individual clips, which are combined into the seam to hold the panels on the roof. The panels are supported to withstand uplift and down loads between the purlins by the continuous clip which spans the distance between the purlins.
FIG. 2 is a front elevation view of the “L” bracket 2 and an individual clip 3 of the type shown in FIG. 1 . The clip 3 is in the form of the numeral 7 , with the end of the upper portion 3 B being bent downward and the end of the lower portion 3 A being bent upward. As will be shown in FIGS. 6A through 6B , the upper end 3 B is used to connect the clip to the roofing panels, while the lower end 3 A can be seen in FIG. 2 to be used to hold the individual clip 3 to the clip support plate 2 B. The lower end 3 A of the clip 3 is held to the support plate by first passing it through a slot 4 in the clip support plate and then it is bent upward against the clip support plate. The slot allows the clip some lateral movement along the longitudinal axis of the support plate as well as some movement orthogonal to this axis to accommodate various loads on the roof as well as the expansion and contraction caused by temperature variations.
FIGS. 2A and 2B shows a second type of individual clip 3 C installed through the hole 4 in the L bracket 2 . This individual clip 3 J is essentially a strip of metal with five bends in it. The first bend is in the middle at point 3 E which divides the strip into a first and a second half. The end of the first half is bent orthogonal to the strip at point 3 F and then again near the tip at point 3 G forming a first flat area 3 H which is similar to surface 3 C in FIG. 2 and a second flat area 3 I at the tip of the strip which is similar to the surface 3 B in FIG. 2 . The end of the second half of the strip is bent in a manner identical to the first half. The two ends of this strip are combined into the roof seam as will be shown in connection with FIGS. 6A through 6C , locking both ends of the strip into the seam for excellent holding power against up lift levels.
FIG. 3 is similar to FIG. 2 with the exception of the ledge 6 which is used for two purposes. The first is to provide a support for a roof panel and the second is as a stiffener to provide added support between purlins. The continuous clip of FIGS. 1 and 2 can be used with either a roof or with purlins. The only difference is that with purlins, the “L” bracket is connected to and supported only at the points where it crosses the purlins. Typically, the continuous clip is ten feet long and purlins are spaced five feet on centers. The continuous clip spans three purlins and is connected to all three.
FIG. 4 is a front elevation view of a second variation of the continuous clip. In this case, rather than an angle bracket, the continuous clip is in the form of a inverted letter “T” with the horizontal portion of the “T” serving as the mounting plate 2 C and the vertical portion of the “T” serving as the clip supports plate 2 D. Raised portions of the mounting plate 2 F are used to support the panel above the head of the mounting screws. There is a downwardly bent upper end of the “T” clip support plate 2 E. The bent down end 2 E serves the same function as the end 3 B in FIG. 2 which is to grip the edge of the panel as shown in FIG. 7 . The panels are not bent. They are merely snapped in place. The panel is held on the top and bottom of the continuous clip all along the continuous clip, even in the spaces between the purlins.
FIG. 5 shows a perspective view of the second variation of the continuous clip and is the continuous clip that is used in FIG. 7 .
FIGS. 6A through 6C show the method of attaching two adjacent panels to a continuous clip of the type shown in FIGS. 1 and 2 . The left hand panel in these Figures is designated 9 F while the right hand panel is designated 9 G. These panels are identical, however, their own individual right and left ends are different. The right end is shown clearly at the right end of panel 9 G. It is shaped like the numeral “7” with a vertical portion 9 H and a horizontal portion 9 D which is connected at one end to the top of the vertical portion 9 H.
The form of the left end of these panels is shown clearly on the left end of panel 9 F. This left end is also configured like the numeral “7” having vertical portion 91 and a horizontal portion 9 C, but it also has an tip 9 E formed from the horizontal portion 9 C that is bend downward. In the middle of this Figure, at the junction of the two panels is a clip 3 . Beneath the clip 3 is the right end of the left panel, while over the clip is the left end of the right panel.
FIG. 6B is identical to FIG. 6A with the exception that where the panels overlap each other in the middle of this drawing, the panel ends and the clip end have been crimped together to form a shape like the numeral “7”. This is referred to as the 90° position.
FIG. 6C is identical to FIG. 6B with the exception that the panel end and clip have been bent another 90° to make a total 180° bend which results in sealing the panels together and connecting the panels to the clip which secures the panels to the roof.
FIG. 7 shows two roof panels 12 A and 12 B which are placed adjacent to one another and are connected to a clip 13 without the need for crimping. These panels and the clip simply snap together. The left hand end of the panel 12 A is in the form of an inverted “U” with a lip 12 E extending outwardly from the lower end of the inverted “U”.
Panel 12 B has an identical shape with the inverted “U” shape portion being located at the left end of this panel. This left end of 12 B is placed beneath the clip 13 . The clip 13 B is similar to the clip shown in FIG. 4 with an inverted “U” shaped top 13 B. This clip is secured to the roof with screw 10 which goes through a mounting plate 13 C located at the base of the clip.
Above the clip 13 is the right hand end 12 D of the panel 12 A. This end is also in the form of an inverted “U” but it is large enough to cover the clip 13 . It has a “V” shaped end 12 F which lies immediately below the lip 12 E of the right hand panel and secures the lip 12 E in place.
In the assembly of these two panels and the clip, the left end 12 C of the right panel 12 B is inserted below and is held in place by the inverted “U” shaped top of clip 13 . The lip 12 E on the bottom of the right end 12 D of the left panel 12 A is placed over the clip 13 and pressed down along side the lip 12 E displacing the lip to the left. After the “V” shaped end 12 F passes the lip 12 E, the lip snaps back from its displacement and is prevented from moving downward by the “V” shaped end 12 F. The left end 12 C is also prevented from moving upward or to the left or right by the clip 13 .
As can be seen from the various configurations presented, the continuous clip can be adapted to many variations in individual clip design as well as methods of sealing and securing the roof panels, however, all of these variations gain the benefits of improved strength, as well as improved ease and speed of installation provided by the use of the continuous clip.
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A roof panel clip that extends ten feet in length rather than the usual prior art one to two inches, enabling the clip to span the distance between two purlins to support roof panels over these distances. The extended length of the clip enables it to provide greater strength against uplift loads than that which was possible with the older narrower clips and this continuous clip can be installed more quickly than a series of the ususal smaller clips used to cover the same span.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus for stabilizing soil and reducing the possibility of structural damage to foundations used to support buildings and dwellings. More particularly, this invention relates to an apparatus for controlling soil moisture content to stabilize forces being exerted against foundations by soil which expands and contracts in relation to its moisture content.
2. Description of the Prior Art
The expansion and contraction of clay soils has resulted in billions of dollars of damage to building foundations. Soils containing clay expand and contract as moisture content changes. Soils with a high content of certain clays can shrink to half their original volume as they relinquish water and dry out from their saturated state. A foundation constructed on those types of soil will experience varying structural loads when the soil expands and contracts. In geographical areas with a wide variation in seasonal precipitation, soil expansion and contraction will cause bending forces in a foundation that cause damage and possibly lead to structural failure.
Another problem occurs when one section of the soil underneath the foundation experiences localized moisture deprivation. Localized depletion is created by the existence of vegetation around a foundation. For example, the roots of a tree present near the foundation will absorb moisture from that specific area causing a localized depletion of soil moisture content. When that occurs, the soil contracts causing that particular foundation section to sag. That, in turn, creates unequal load stress about the entire foundation resulting in structural failure. Traditionally, piers have been installed after structural damage to prevent the foundation from further movement. However, in many instances piers may not be a permanent solution, and they are costly to the homeowner.
Systems have been developed which attempt to maintain the soil at a constant level of moisture. The aim is to prevent wet-dry cycles and thereby prevent the volume changes in soil that cause foundation damage. One such system is disclosed in U.S. Pat. No. 4,534,143 issued to Goines et al. The system of Goines et al. operates to supply water to the soil surrounding a foundation to produce a stable soil moisture level and prevent foundation stress. However, the fact that the Goines et al. system can only add water in preset amounts and at preset times is a serious drawback. It will continue to add water during rainy periods and can worsen the puddling of water around a foundation. Conversely, when hot, dry periods occur, the preset water is inadequate to stabilize the moisture content which can lead to serious soil shrinkage and foundation damage. Furthermore, the Goines et al. system cannot compensate for localized moisture depletion as might be caused by a large tree. The overlying foundation can experience a downward deflection into the localized area of decreased support and damage a foundation despite the presence of the functioning watering system. Even at its best, the Goines et al. system demands sound judgment about weather and its affects causing frequent adjustment by the system's owner.
An improvement over the Goines et al. system is disclosed in U.S. Pat. No. 4,878,781 issued to Gregory et al. The Gregory et al. system addresses the problem of seasonal changes by installing a flow regulator preset to a relatively high flow of water during hot and dry seasons and a relatively low flow of water for cooler and less dry seasons. However, the Gregory et al. system provides only for seasonal changes and still relies upon human judgment and frequent resetting for foundation protection. As with Goines et al., hazards remain from the potential for too much or too little water.
Another system that addresses the problem of localized soil moisture depletion is disclosed in U.S. Pat. No. 4,879,852 issued to Tripp. That system provides water to the soil underneath the foundation on a demand basis and also provides for a localized dispersion of water. Additional water can, therefore, be supplied to those areas that are lacking, such as those near plants and vegetation, without wasting water on those areas sufficiently hydrated. The Tripp system uses a series of moisture sensors placed beneath the surface of the soil to determine the localized water depletion. A control box containing an electronic processor located near the foundation receives and processes the signals from the moisture content sensors. After the moisture content of various areas around the foundation has been determined, water is introduced into those areas based upon the amount of dehydration. The electronic processor controls various sets of control valves to allow water to flow to each of the areas until the selected water content of that area has been met. The control valves are then closed by the electronic processor until water is again needed.
Although the Tripp system is said to be more effective than previous systems, it will not be in clay-based soils. In clay, conventional moisture content sensors are subject to serious measurement inaccuracies, often greater than plus or minus 50%. These occur because most conventional moisture content sensors measure the dielectric constant of the water in comparison to the dielectric constant of the surrounding soil in order to determine the overall moisture content of the soil. Specifically, measurement inaccuracies in clay occur because the dielectric constant of water is approximately 80 and the dielectric constant of clay ranges in the magnitude of 10 6 through 10 7 . Determining changes in the dielectric constant of water as measured against the dynamic range of the dielectric constant of clay is difficult and prone to produce inaccurate results. The available technology for the precise moisture measurement in clay is cost-prohibitive to most homeowners. The Tripp system, therefore, is subject to inherent errors in measuring the moisture content of the soil that can cause either excessive watering of a localized area, erosion or underwatering which produces the localized foundational stress that causes structural damage.
The present invention overcomes those problems and other problems by replacing the moisture content sensors used in conventional foundation stabilization systems with specialized stress sensors. The sensors of the present invention are specifically designed to measure foundation stress resulting from the expansion or contraction of underlying soil based on moisture content. The system of the present invention introduces water into either all of the surrounding soil or specifically into localized areas until the force exerted on the foundation is equalized and at the proper level. The stress sensors of the present invention provide a much more accurate means of controlling soil movement. The prevention of damaging soil movement beneath a foundation, and the maintenance of soil stability when the foundation is positioned in a desirable manner are the ultimate aims of a foundation watering system. The present invention delivers into foundation soil variable amounts of water in a quantity sufficient to maintain the desired foundation alignment. In so doing, the problems of moisture measurement in soil and the complexities of weather prediction are bypassed. Highly precise strain gauges are placed at various locations about a foundation to sense foundation loads. In response to changes in foundation stress as measured by the strain gauges, water is precisely delivered to the various locations in order to maintain ideal loads.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a system for maintaining a constant level of moisture in the soil supporting the foundation of a house or building such that the addition or depletion of water by environmental conditions will not cause the soil to expand or contract, causing damage to the foundation it supports.
It is a further object of the present invention to provide a sensing means to detect the stress applied to a foundation by expansive soil.
It is another object of the present invention to continuously monitor foundational stress so that if that stress drops below a calibrated level, water will be injected into the soil surrounding the foundation to prevent torquing of that foundation by uneven stresses.
It is yet another object of the present invention to provide a soil moistening system that counteracts localized deprivation of water.
It is also an object of the present invention to provide a soil moistening device that is fully automatic and does not require the attention of the owner of the property.
It is still another object of the present invention to provide a device that can be easily installed for either a new foundation or a foundation of an existing home.
It is yet another object of the present invention to provide a system that is inexpensive to install.
Many other features, objects, advantages and details of the present invention will be apparent from the following detailed description of a preferred embodiment of the invention, particularly when considered in light of the prior art and in conjunction with the appended claims and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG 1a illustrates a soil moistening system pursuant to the present invention showing the positioning of the sensor and porous pipe under a foundation and a portion of the control system, specifically, the control box and solenoid box.
FIG. 1b illustrates the present invention surrounding a typical foundation and showing a possible placement for the stress sensors and porous pipe to create the watering zones.
FIG. 2a is a side view illustrating a stress sensor according to the present invention.
FIG. 2b is a top view illustrating a stress sensor according to the present invention.
FIG. 3 is a cross-sectional view of a protective coating system according to the present invention for strain gauge.
FIGS. 4a-4g are the schematical diagrams of the electrical control system.
FIG. 5 is a flow chart showing system operation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1a and 1b, an overview of the installation and apparatus of foundation stabilization system 10 will be discussed. Stress sensor 11 is positioned under foundation 12 with strain gauge 13 being connected to control box 14 through wire 15. Porous pipe 16 is buried under or adjacent the foundation and fluidly connected to a main water source (not shown) through fluid connector 30 routed through solenoid box 17. Control box 14 is electrically connected to solenoid box 17 to turn the water on and off through solenoids (not shown) in solenoid box 17.
Electrical wires 18, 19 and 20 are connected to remaining stress sensors 24, 25 and 26 (FIG. 1b) positioned about the foundation. Pipes 21, 22 and 23 are the fluid connections to porous pipes or sections 27, 28 and 29 positioned about the foundation as shown in FIG. 1b. For the purposes of a preferred embodiment, four stress sensors 11, 24, 25 and 26 and porous pipes or sections 16, 27, 28 and 29 creating four zones for watering are disclosed, however, one skilled in the art will recognize that any number of sensors and porous pipes or sections may be laid in various zones about the foundation to deliver sufficient amounts of water to ensure proper moisture content and prevent structural foundation damage.
Referring to FIGS. 2a and 2b the components and method of operation of a stress sensor 11 of the preferred embodiment of the present invention will be discussed. Base 32 is inserted under a foundation and provides support for threaded rod 31 and strain gauge 13. Rod 31 fits partially inside of base 32 and is held in place by the combination of a nut 33 and washer 34. Rod 31 is further threadably adjustable through the movement of nut 33 and therefore, may be adjusted to fit directly beneath the underside of a foundation. A suitable support for the stress sensor should preferably be provided. Strain gauge 13 is preferably of the directionally sensitive type which senses a drop in the vertical column portion of stress sensor 11 caused by the reduction of moisture in the soil lying underneath base 32. That motion is changed into a electrical signal which is used to control the addition of water to the zone of sensor 11. Strain gage 13 may further be equipped with a thermal compensation gauge (not shown) which compensates for any change in reading of strain gauge 13 caused by a change in temperature. The operation of strain gauge 13 to produce that signal will be discussed below with reference to the electrical control system.
With reference to FIG. 3, the protective coating for the strain gage will be discussed. After strain gage 13 is mounted on base 32 and lead wire 15 attached to terminal 36 which provides the electrical connection between strain gage 13 and the electrical control circuit, a layer of butyl rubber 37 is applied followed by a layer of aluminum tape 38. Lastly, a layer of nitrate rubber 39 is applied over the entire surface of the strain gauge. The purpose of the protective coating is to protect the strain gauge from water damage which would result in inaccurate readings.
With reference to FIG. 4a, the operation of stress sensor 11 will be discussed. As the soil underneath stress sensor 11 shrinks away from the vertical column portion of stress sensor 11, a minute motion occurs which is sensed by strain gauge 13 (see FIG. 1a). Terminal 36 of strain gauge 13 is connected to Wheatstone bridge 41 and strain amplifier 40 through electrical connector J1. When the foundation is level, the resistance of strain gage 13 is such that Wheatstone bridge 41 is balanced and the output on channel 1 from strain amplifier 40 is a constant level which represents a level foundation. However, when the vertical column portion of stress sensor 11 shrinks away from foundation 12, the resistance of strain gage 13 decreases which unbalances Wheatstone bridge 41. That unbalance changes the input signal to strain amplifier 40 in proportion to the amount of unbalance. The input signal is amplified by strain amplifier 40 and output on channel 1 as a signal representing the amount of soil shrinkage. Wheatstone bridge 41 is provided with a reference signal, VREF, used to balance the bridge through potentiometer 101 when the foundation is level. VREF is a 2.5 volt signal generated as shown in FIG. 4c. Five volt DC source 95 is limited by zener diode CA7 to 2.5 volts. That 2.5 volt signal is buffered through amplifier 42 and output as VREF. For the purposes of discussion, only one stress sensor operation was discussed, however Wheatstone bridges 74, 75 and 76 and strain amplifiers 77, 78 and 79 operate in exactly the same fashion as above and output signals representative of soil shrinkage from the remaining three stress sensors. Furthermore, one skilled in the art will readily recognize that any number of stress sensor circuits could be constructed to monitor additional zones.
Referring to FIG. 4b, the signals from each of amplifiers 40 and 77-79 are output to multiplexer 43 where, based upon the logic generated by microcontroller 45 (FIG. 4d) and output to multiplexer 43 over select lines 0-2 (see Table 1), one of the four channels or the CUR or CAL signal (discussed herein) will be sent to A to D converter 44. In the preferred embodiment, A to D converter 44 uses voltage controlled oscillator 80 to produce a signal with a frequency having a rate proportional to the applied voltage from multiplexer 43 which is output to an interrupt on microcontroller 45 (see FIG. 4d) over line ADC.
Again referring to FIG. 4c, the 2.5 CAL signal will be discussed. The 2.5 volt signal is generated in exactly the same method as the 2.5 VREF signal except that amplifier 64 is used as a buffer. The CAL signal is applied to the multiplexer 43 and during initialization of the entire system it is selected by microcontroller 45 and used as a known voltage reference signal to calibrate voltage controlled oscillator 80.
TABLE 1______________________________________CT LOGIC SELECTED SIGNAL______________________________________000 CH 1001 CH 2010 CH 3011 CH 4100 CUR101 CAL______________________________________
Microcontroller 45 is programmed to count the number of interrupts over a predetermined period (one second in the preferred embodiment) to determine the frequency of the signal sent over line ADC and thereby, determine the voltage because of its proportionality to the frequency. That measured voltage signal, which represents the stress being applied against the foundation, is compared with a set point, which represents the stress applied against the foundation when the foundation is level, and is stored in EEPROM 46 (FIG. 4d). If the measured signal is less than the stored set point, then soil shrinkage has occurred and water must be added to the particular zone. Microprocessor 45 is programmed to send a signal is then sent over one of ON/OFF lines 1 through 4 to turn on the appropriate solenoid and water the correct zone.
Referring to FIG. 4e, the solenoid operation will be addressed. By way of example, if zone 1 is selected, microcontroller 45 will set -ON/OFF line 1 low. NOR gate 47 is used to prevent the solenoid from being turned on if it is faulty or if there is a system malfunction. As long as the system is functioning properly, the FAULT signal (generation of the FAULT signal will be discussed herein) remains low and therefore, the output of NOR gate 47 to transistor Q1 will be high. The output from transistor Q1 is used by optoisolater 48 to drive SCR (silicone controlled rectifier) 49 which is used to switch a 24 VAC source (not shown) to the solenoid under its control. SCR's 50-52 operate the remaining three solenoids to deliver water to their respective zones, however, SCR 53 operates a fail safe solenoid (not shown) which closes a valve (not shown) to shut off the main water to all four zones in the event of a malfunction such as a solenoid being stuck open. The operation of NOR gates 81-84, transistors Q3, Q5, Q7 and Q9 and SCR's 85-88 are the same as described above. Also in the circuit between SCR's 49 through 53 and the 24 VAC source are thermistors 54 through 58 (FIG. 4f). Thermistors 54 through 58 act as buffers between the 24 volt AC source and the solenoids to provide protection against fire.
Referring to FIG. 4f, the electronic control system power supply will be discussed. The 24 VAC power supply (not shown) is applied across bridge rectifier 89 and then to switching power supply 90 which converts the 24 VAC signal to a 5 VDC signal. That 5 VDC signal is then used to power microcontroller 45 and its associated circuitry.
Again referring to FIG. 4f, a further fail safe feature will be discussed. The current delivered to the selected solenoid is monitored by microcontroller 45. To measure the current applied to the solenoids for diagnostic purposes, the voltage drop across resistor R86 is converted to a DC signal by amplifiers 59 through 62 which are used as precision rectifiers. The DC signal is then input into instrumentation amplifier 63 which converts the differential rectified signal to single ended which is then amplified by amplifier 65 and sent to multiplexer 43 over the line marked CUR. Microcontroller 45 periodically outputs the CUR select logic (see Table 1) over select lines 0-2 to multiplexer 43 which then outputs the CUR signal to A to D converter 44. The CUR signal is converted to digital and read by microcontroller 45. That signal, which represents solenoid current, is then processed by microcontroller 45 to determine if the solenoid is drawing too much current or no current at all. In either instance, microcontroller 45 generates an error signal over the ERROR line (discussed herein) which will turn off the entire system.
Referring to FIGS. 4d and 4g, the monitoring and fail safe system will be discussed. "Watchdog" timer 66 serves to monitor the 5 volt line and the HART signal generated by microcontroller 45 and to reset the system if there is an error. The HART signal is a toggle signal, namely a pulse train, input into the clear pin of a second "watchdog" timer 67 (FIG. 4g) used to continually reset that timer. Also, during normal operation, the HART signal is input into NOR gate 68 causing lamp D2 to flash denoting proper system operation. However, if the microcontroller malfunctions, the HART signal ceases to be generated and becomes low. Therefore, watchdog timer 67 is not reset and subsequently times out. When that occurs, watchdog timer 67 outputs a low signal which is latched by flip-flop 69 causing it to change state. The Q pin of flip-flop 69 goes high resulting in a low signal being output from NOR gate 70. That signal is input into NOR gate 100 causing it to output a high signal. The output of NOR gate 100 is input with the HART signal (now low) into NOR gate 68, the output of which turns off light D2. The output of NOR gate 70 is also input along with the output of "watchdog" timer 67 into NOR gate 71 resulting in a high output. That output is used to beep speaker 72 and light lamp D3 denoting a system malfunction.
As an additional fail safe, microcontroller 45 monitors the system through diagnostic signals such as CUR, and upon the detection of an error outputs an error signal over the line marked ERROR (FIG. 4d). While the system is functioning properly, the error signal input from microcontroller 45 into NOR gate 70 remains low. However if the microcontroller detects a system error, that signal will go high causing NOR gate 70 to output a low signal. Also in response to an error, the microcontroller will turn off the HART signal causing "watchdog" timer 45 to output a low signal as described above. The outputs of "watchdog" timer 67 and NOR gate 70 are input into NOR gate 71 resulting in a high output. That output is again used to beep speaker 72 and light lamp D3. The output of NOR gate 70 is input into NOR gate 100 causing it to output a high signal. That signal is input into NOR gate 68 with the HART signal to ultimately turn off lamp D2 as previously described.
On any system error, all the solenoids will be turned off. That occurs because the FAULT signal, generated by the output of NOR gate 100, changes to a high output causing NOR gates 47 and 81-84 shown in FIG. 4e to output low signals, thereby, removing all power from the solenoids and stopping system operation.
Again referring to FIG. 4d, system calibration and manual control will be discussed. LCD display 72 is used to display the menu options available to a system operator. A system operator presses select switch SW2 to display the menu options and presses the execute switch SW1 to execute those options. The menu options are: calibrate the entire system; calibrate each sensor individually; read actual stress sensor measurements individually; retrieve set point data and turn on each individual solenoid. A system operator wishing to turn on an individual solenoid presses execute switch SW1 which causes microcontroller 45 to output a signal on the selected -ON/OFF line and the individual solenoid is turned on as discussed above with reference to automatic operation. To calibrate the entire system execute switch SW1 is pressed when the calibrate entire system option is displayed on LCD 72. Initially, the moisture content of the clay soil is increased to its maximum amount. Microcontroller 45 then reads the present measurement of foundation stress measured by each sensor at that maximum amount and stores that measurement in EEPROM 46 to serve as the set point data representing a level foundation. The bank of resistors denoted by numeral 73 are used as pull up resistors to increase the current outputted from microcontroller 45 to levels necessary for proper system operation.
Referring to the flow chart of FIG. 5, automatic system operation will be discussed. After the system is restarted, a self test is run. Microcontroller 45 then compares the measurement of sensor 1 with the set point for that zone, determined as described above. If that measurement is less than the set point, meaning that the soil in zone 1 has lost moisture, then the water is turned on and left on until sensor 1 registers proper foundational pressure. Microcontroller 45 next compares the measurement of sensor 2 with its set point and turns zone 2 on or off accordingly. Sensor 3 is then checked and zone 3 is turned on or off, and finally sensor 4 is checked and zone 4 turned on or off. Microcontroller 45 then returns to check sensor 1 and the process repeats. Microcontroller 45 will continually monitor each zone and add water to stabilize the soil moisture content and prevent structural foundation damage unless there is a system malfunction as discussed above.
Although the present invention has been described in terms of the foregoing embodiment, such description has been for exemplary purposes only and, as will be apparent to those of ordinary skill in the art, many alternatives, equivalents, and variations of varying degrees will fall within the scope of the present invention. That scope, accordingly is not to be limited in any respect by the foregoing description, rather, it is designed only by the claims which follow.
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The present invention is a moisture stabilization control system used to prevent structural damage to foundations resulting from forces exerted by the expansion and contraction of underlying soil. Stress sensors are employed to monitor the stress applied against the foudnation. When abnormal amounts of stress are sensed by the system, it compensates for the decreased support of the foundation by injecting water into the soil supporting that foundation until the level of stress is equalized and at the proper amount. The present invention is designed such that it can provide water to the soil in specified zones, thereby relieving localized depletions and preventing substantial structural damage to any foundation.
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[0001] This patent application claims priority to provisional patent application Ser. No. 61/073,021 filed Jun. 16, 2008 and to provisional patent applications Ser. No. 61/097,456 filed Sep. 16, 2008.
FIELD OF THE INVENTION
[0002] The invention is in the field of torque hubs used to supply power and torque to drive wheels of vehicles.
BACKGROUND OF THE INVENTION
[0003] Small boom lifts, for example those less than 15,000 lbs. gross vehicle weight, are generally two wheel drive battery powered machines for indoor use only. The wheels on these machines are primarily driven with electric motors and planetary gearboxes on the non steering axle of the machine. The configuration of this electric drive system is extremely long and makes it impossible to drive the steering wheels because the electric motor extends too far and interferes with the operation of the vehicle by engaging the frame of the vehicle. In addition, because these electric motors are normally in the non-steer axle on an indoor machine, they do not have (or need) any sort of environmental protection.
[0004] The major hurdle for putting a hybrid electric system in a large gross vehicle weight machine, prior to the invention described and claimed herein, is that the same type of electric drive assembly used on small boom lifts cannot be used in large boom lifts. Therefore, there is a need for an electric drive assembly that has a higher power density and is environmentally protected. The instant invention solves the problem and answers the need.
SUMMARY OF THE INVENTION
[0005] The invention is an electric wheel drive assembly which includes a high speed electric motor, an internal brake and a three stage gear reducer. It can be used on aerial work platforms (boom lifts, large scissors lifts), tele-handlers, large fork lifts, agricultural vehicles and the like. The drive is powered with three phase electrical power to an induction AC motor. The front end of the motor shaft is supported by a bearing contained within an electromagnetic brake which is spring applied, electromagnetic release. The brake includes a friction disc which is connected (splined) to the motor shaft and provides parking and emergency braking. The motor shaft connects to the sun gear of a triple planetary gearbox with a gear reduction range of 90:1 to 160:1. The first two planetary stages are nested within the diameter of the main wheel support bearings. The output planetary stage resides toward the cover end and outputs to the ring gear which drives the wheel hub. The cover contains a cap secured with two screws that can be removed and then the cap may be flipped acting on rods 113 and 109 to disengage the assembly from the motor and brake. A rod pushes into the assembly against the force of a spring and disconnects a splined connection.
[0006] The invention provides advantages in the market in that an electric wheel drive may be used for a heavier machine. By way of example a boom lift type machine is described. However, the invention is not limited to this machine. Large boom lifts greater than 15,000 lbs. gross vehicle weight are generally suited for outdoor work and they can be two wheel drive or four wheel drive. Wheels on these machines are generally driven with hydraulic motors and planetary gearboxes. Hydraulic systems required to propel the wheels present a problem because the hydraulic system is typically driven by an internal combustion engine sized for the peak power and torque required out of the machine. Boom machines are very rarely operated at their peak power, for example, when climbing a steep grade (usually during loading on a trailer). Regardless of the output power required at the wheels or other systems, the hydraulic system constantly demands peak power out of the internal combustion engine, making it a very inefficient machine. With increasingly stringent emissions standards, consumers are considering a conversion of their boom lifts to machines employing hybrid electric systems.
[0007] A compact gear reducer electric motor assembly with an internal brake is disclosed and claimed wherein a high speed electric motor is interconnected with a gear reducer having substantial gear reduction. High power density is created by employing a high speed AC motor with a maximum speed of 6000 rotations per minute with a very compact high reduction gear box with a brake nested substantially within the windings of the motor. The assembly includes a spindle and a brake mounted substantially within the high speed electric motor. The brake is operable against a spring biasing said brake into engagement with an friction plate. The brake is electrically actuated which disengages the pressure plate from the friction plate or disc to permit rotation of the motor shaft and transmission of energy to the gear reducer.
[0008] The gear reducer includes input, intermediate and output planetary stages. The input and intermediate stages reside within the spindle and the output planetary stage drives an output ring gear. Releasing means for releasing the output ring gear from the brake allow rotation thereof such that the machine may be moved or towed.
[0009] The invention includes packaging the high speed planetary stages, for example the input and intermediate stages, within the main support bearings. Traditionally, the high speed gearing in a planetary wheel drive gearbox is towards the cover end. By housing the high speed stages within the bearings, three planetary stages are supported in a shorter axial length.
[0010] The invention, in one example, “nests” or houses the brake withing the winding end turns of the electric motor. AC induction motors have long winding end turns that normally just occupy space. The invention utilizes this space as a place for the brake housing thus reducing the axial length of the motor-brake-gear reducer by approximately 1 inch.
[0011] The brake provides bearing support for the end of the motor shaft. A bearing is interposed between the motor shaft and the brake. The compact gear reducer electric motor assembly includes a high speed electric motor interconnected with a gear reducer having a gear reduction in the range of 1:90 to 1:160. The gear reducer includes a spindle and a disconnect shaft. The disconnect shaft transmits energy of the high speed electric motor to the gear reducer. An internal brake includes a housing and springs mounted therein and an electromagnetic coil therein.
[0012] The internal brake includes a friction plate affixed to the spindle. The internal brake further includes a housing and first and second pressure plates. The first and second pressure plates each include a passageway therethrough. A spacer resides between the first and second plates. The friction plate is affixed to the motor shaft and is rotatable therewith. The friction plate is generally disk-shaped having first and second sides and includes frictional material affixed thereto on the first and second sides thereof.
[0013] The springs of the brake are operable between the housing of the brake and the first pressure plate. The pressure plates are ferromagnetic and attractable by the coil of the brake when the coil is energized. The spring urges the first pressure plate into engagement with the friction plate when the coil is de-energized. The internal brake is substantially within the high speed electric motor.
[0014] The brake is electrically actuated to permit transmission of energy to the gear reducer. The gear reducer includes input, intermediate and output planetary stages. The input and intermediate stages reside within the spindle. The output planetary stage drives an output ring gear. The electric motor includes a shaft and the electric motor includes electric windings radially spaced from the shaft creating a void or space between the shaft and windings. The electric brake resides substantially within the space between the shaft and the windings. The input planetary stage includes an input planet sun gear and planet gears. The planet gears of the input stage have a first width and the intermediate planetary stage includes an intermediate sun gear and intermediate planet gears. The intermediate planet gears have a second width. The first width of the input stage gears is less than one-half the width of the intermediate planet gears having a second width.
[0015] Other examples employ different orientation of the brake assembly and different configurations of the planetary gear stages.
[0016] It is an object of the invention to provide a torque hub having a high speed electric motor, internal brake, and a gear reducer in a small volume.
[0017] It is a further object of the invention to provide a torque hub having a high speed electric motor which through a gearing reduction provides large torque for movement of the vehicle against a heavy load.
[0018] It is a further object of the invention to provide a torque hub which is relatively short as compared to a hydraulically driven motor enabling the vehicle to turn.
[0019] It is a further object of the invention to provide a torque hub which includes a brake substantially residing within an electric motor.
[0020] It is a further object of the invention to provide a torque hub which is short and compact.
[0021] It is a further object of the invention to provide a torque hub utilizing a gearbox wherein first and second stages thereof reside within the spindle and the third stage resides within an outer ring gear providing a quiet gear box with large speed reduction.
[0022] It is a further object of the invention to provide a torque hub which is short and compact and which employs sun planet gears which are less than one-half the width of the intermediate planet gears.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a cross-sectional assembly view of the preferred example of the motor-brake-gear reducer with the brake housing residing substantially within the electric motor.
[0024] FIG. 1A is an enlargement of a portion of FIG. 1 illustrating the input planet gears and intermediate planet gears.
[0025] FIG. 1B is an enlargement of a portion of FIG. 1 illustrating a portion of the brake.
[0026] FIG. 1C is a perspective view of the assembly of the preferred example of the motor-brake-gear reducer.
[0027] FIG. 2 is a cross-sectional assembly view of another example of the motor-brake-gear reducer.
[0028] FIG. 2A is an enlargement of a portion of FIG. 2 illustrating the input planet gears and intermediate planet gears.
[0029] FIG. 3 is a cross-sectional assembly view of another example of the motor-brake-gear reducer.
[0030] FIG. 3A is an enlargement of a portion of FIG. 3 illustrating the input planet gears and intermediate planet gears.
[0031] FIG. 3B is an outside perspective view of the example illustrated in FIGS. 3 and 3A .
[0032] FIG. 4 is a cross-sectional assembly view of another example of the motor-brake-gear reducer.
[0033] FIG. 4A is an enlargement of a portion of FIG. 4 illustrating the input planet gears and intermediate planet gears.
[0034] FIG. 4B is an outside perspective view of the example illustrated in FIGS. 4 and 4A .
DESCRIPTION OF THE INVENTION
[0035] FIG. 1 is a cross-sectional assembly view 100 of the preferred example of the motor-brake-gear reducer with the brake housing residing substantially within the electric motor. Referring to FIG. 1 , reference numeral 101 A is a steel spindle/input ring gear which houses the planetary gear stages. Lip seal 101 B seals the gap between the spindle/input ring gear and the wheel hub 101 D. Main bearings 101 C support the wheel hub 101 D and output ring gear 101 E for rotation relative to the spindle 101 A. Bearing nut 101 F and set screw 101 G secure the bearings 101 C in place longitudinally. Internal gears and gearbox components are made of steel or stainless steel. Spindle 101 A is steel or a steel alloy.
[0036] FIG. 1A is an enlargement 100 A of a portion of FIG. 1 illustrating the input planet gears 102 F and intermediate planet gears 103 F. Input carrier 102 A along with thrust plates 102 B are illustrated in FIG. 1A . Input planet pins 102 E secure input planet gears 102 F to the input planet carrier 102 A. The input planet gears 102 F are secured by the input planet pin retaining rings 102 G. Input planet gears 102 E are driven 180 by input sun gear 110 which is driven by splined 172 disconnect shaft 109 . Retaining ring 112 retains the intermediate sun gear and the input planet carrier.
[0037] Still referring to FIG. 1A , input planet gears 102 F include 35 carburized teeth and are driven by carburized input sun gear 110 having 19 teeth. Input thrust plates 102 B secure input planet gears 102 F to the input planet pins 102 E. Input/intermediate planet bushings 103 C support input planet gears 102 F and intermediate planet gears 103 F. Input planet pin retaining rings 102 G secure thrust plates 102 B in place to retain input planet pins 102 E. Input sun gear 110 is trapped against longitudinal movement by motor shaft 141 and intermediate sun gear 116 . Similarly input thrust washers 103 B secure intermediate planet gears 103 F to the intermediate planet pins 103 E. Input carrier 102 A is driven by input planet pins 102 E and is splined 173 to intermediate sun gear 116 . Intermediate sun gear 116 includes 19 carburized teeth and drives 180 intermediate planet gears 103 F which interengage and react against teeth of internal ring gear 188 of spindle 101 A.
[0038] Intermediate sun retaining ring 112 retains input carrier 102 A. Thrust spacer 120 resides between input carrier 102 A and intermediate carrier 103 A. Intermediate carrier roll pin 103 G secures the intermediate carrier 103 A to the intermediate pin 103 E. The intermediate carrier 103 A serves to maintain and secure the thrust washers 103 B in place. A shoulder (unnumbered) on output sun gear 111 secures the intermediate carrier 103 A in place and hence the intermediate gears in place as well. See FIG. 1 . Output carrier 104 A is splined 174 A to the internal ring gear 199 of the spindle 101 A and is stationary (fixed or is grounded). It should be noted that the input planet gears, the input carrier, the intermediate planet gears and the intermediate carrier are permitted to move longitudinally a small distance limited by retaining rings, thrust spacers and the other structure of the elements in proximity thereto.
[0039] FIG. 1B is an enlargement of a portion of FIG. 1 illustrating a portion 100 B of the brake 108 A. Inertia Dynamics Incorporated (hereinafter “IDI”) manufactures the spring applied-coil energized to release brake described herein. The IDI brake is adapted to be mounted to the spindle 101 A of the gear reducer in a direction opposite to the normal orientation so as to economically use the space 197 available within the spindle and the electric motor. The normal orientation of the brake can be viewed in FIGS. 2-4 . Energized coil 130 in brake 108 A attracts ferromagnetic actuating plate 126 (sometimes referred to as the clapper) against the force of springs 164 and away from friction plate 125 to permit friction plate 125 to rotate with motor shaft 141 / 141 A. See FIG. 1 . When coil 130 is actuated, plate 126 abuts body 108 A of the housing and gap 169 illustrated in FIG. 1B is eliminated. Coil 130 is a direct current coil operable at 80 Volts direct current, 27 Watts.
[0040] Friction plate 125 includes friction material 125 A affixed thereto. Adhesive is used to affix the friction material to the friction plate. The friction material is located near the circumferential extent of the friction plate 125 . When the brake is applied, springs 164 urge the actuating plate 126 against the friction plate 125 and, in particular, against the friction material 125 A affixed to the friction plate 125 . As illustrated in FIG. 1B , the friction material 125 A is illustrated against and in engagement with plates 126 and 124 . Plate 124 is shown pinned 162 to the spindles 101 A as the spacer or standoff 161 is trapped between the body 108 A of the brake and the pressure plate 124 . Spacer or standoff 161 includes a passageway 163 therethrough for bolt 199 . Similarly, plate 126 includes a passageway 163 P for the spacer to reside. Pressure plate 124 includes a passageway 163 Q for bolt 199 to reside. Bolts 199 secure the housing 108 A to the spindle 101 A and prevent rotation of the plates 124 , 126 . Bolt 199 , housing 108 A and spacer 161 secure plate 124 against and into engagement with spindle 101 A. Bolt 199 is illustrated forcing body 108 A against the spacer 161 which in turn forces the spacer against the pressure plate 124 which in turn forces the pressure plate 124 against the spindle 101 A. There are three bolts 199 and numerous springs 164 used in the assembly. Brake 108 A is sealed 108 C against the spindle 101 A.
[0041] FIG. 1C is a perspective view 100 C of the assembly of the preferred example of the motor-brake-gear reducer illustrating the exterior of the motor 107 A (Advanced 72V alternating current motor, IP67 protection rating), spindle 101 A, the hub 101 D, and the exterior of the output ring gear 101 E. Motor 107 A is an Advanced 72 Volt alternating current motor carrying an IP 67 protection rating. IP stands for ingress protection and “6” is the highest rating for protection of dust infiltration and “7” is a rating for water infiltration when the enclosure is submersed 15 cm to 1 meter for 30 minutes.
[0042] Referring to FIGS. 1 and 1C , motor 107 A has a generally cylindrically shaped tapered exterior. Motor shaft 141 / 141 A is an interference fit. Spring 140 bears upon disconnect shaft 109 . Towing of the machine is accomplished by reversing the orientation of the unnumbered cap which involves removal of the unnumbered screws. Once the orientation of the cap is reversed and is bolted in place, it forces an unnumbered rod leftwardly which forces rods 113 and 109 leftwardly. Once the disconnect cap is removed, the orientation of the cap is reversed such that the button portion of the cap is reversed (oriented leftwardly) pushing an unnumbered rod which acts upon disconnect rod 113 and disconnect shaft 109 moving them leftwardly causing disengagement of shaft 109 from the sun gear 110 . The bolts (unnumbered) are used to hold the button onto the cover 106 A. The reversely oriented button thus disconnects the motor from the gearbox putting it in the tow mode. Bushings 189 support internal disconnect rod 113 . Motor shaft 141 / 141 A is supported by bearings 142 at the generally leftward end of the motor and is supported by bearings 190 at the generally rightward end of the motor. Bearings reside between stationary brake 108 A and shaft 141 A. Brake 108 A is bolted with bolts 199 to spindle 101 A. Motor 107 A is sealed 107 C with O-rings to prevent the intrusion of water or dust at the joint of the spindle and motor. Motor 107 A is affixed to spindle 101 A with bolts which are unnumbered in FIG. 1C . Motor 107 A is sealed such that the wires which supply power to the motor and the coil as well as wires which communicate with sensor 128 pass through the motor enclosure such that they are sealed from the intrusion of dust and water.
[0043] Brake 108 A is mounted in a direction such that the coil 130 protrudes into a cavity or volume 197 between the motor's windings 123 and the shaft of the motor 141 / 141 A. Brake 108 A resides in the diametrical bore 196 of one end of the spindle 101 A. Bearings 190 are tensioned and retained in place by spring 108 E operable between ring 108 D residing in a groove in an inner diametrical bore of the brake and the bearing 190 . Spring 108 E urges bearing 190 against a shoulder on the exterior of the shaft 141 A. Spindle 101 A forms intermediate ring gear 188 .
[0044] Referring to FIG. 1A , input sun gear 110 is carburized and has 19 teeth. Input sun gear 110 is splined 172 to the disconnect shaft 109 . Input carrier 102 A is splined 173 to the intermediate sun 116 which in turn drives intermediate planet gears 103 F. Intermediate sun 116 and intermediate planet gears 103 F intermesh 181 with each other. It will be noticed that FIGS. 1 and 1A depict input planet gears 102 F which are less than one-half as wide as the intermediate planet gears 103 F which results in positioning the first and second planetary stages within ring gear 188 within the spindle 101 A thus saving axial space within the gearbox while effectively and efficiently transmitting power and torque.
[0045] Referring to FIGS. 1 and 1A , input seal 108 F and brake O-ring 108 C seal the gearbox from the motor preventing unwanted lubricating oil in the motor. Hub 101 D is affixed to output ring gear 101 E with bolts 101 M. Main lip seal 101 B seals between the output ring gear 101 E, hub 101 D, and the spindle/input ring gear 101 A. Main bearings 101 C interengaging wheel hub 101 D and spindle 101 A enabling rotation of the wheel hub 101 D with respect to the spindle 101 A which is affixed to the vehicle and is not rotatable. Bearing nut 101 F and set screws 101 G ensure that bearings 101 C are secured against the spindle 101 A. Seals such as elastomeric O-ring seals 118 are used in the gearbox where necessary.
[0046] Still referring to FIGS. 1 and 1A , intermediate gears 103 F drive intermediate carrier 103 A which is splined 174 to output sun gear 111 . The intermediate stage planet gears have 35 teeth. Carburized output sun gear 111 includes 25 teeth and drives 182 output planet gears 104 F which interengage teeth 188 A of the output ring gear 101 E. There are four output planet gears; however, different numbers of output planet gears may be used such as 3 or 5. Output carrier 104 A positions the output planet gears 104 F and output planet pins 104 E apart from the first (input stage) and the second (intermediate stage) and within the output ring gear 101 E. The number of teeth employed by the input planet gears, intermediate planet gears, and output planet gears are by way of example only as the invention includes the flexibility to employ different ratios by changing tooth combinations in the input and intermediate stages.
[0047] Still referring to FIGS. 1 and 1A , the output planet carrier 104 A is stationary. Spline 174 A of the output planet carrier is interconnected with the internal ring gear 188 of the spindle. Therefore, the output carrier 104 A is stationary. Output planet pins 104 E are fixed within the output planet carrier 104 A. Output planet gears 104 F rotate about stationary output planet pins 104 E and intermesh 188 A with the output internal ring gear causing it to rotate and drive a wheel (not shown) affixed by studs 101 M and nuts (not shown). Output planet thrust washers 104 B abut the output carrier 104 A and prevent side to side movement of the output planet gears 104 F. Output planet needle rollers 104 C are separated by an output planet spacer 104 D and enable rotation of the output gears 104 F with respect to output planet pins 104 E. Output planet roll pins 104 G secure the output planet pins 104 E to the output planet carrier 104 A.
[0048] A double walled intermediate carrier 103 A is splined to the output sun gear 111 . Intermediate planet thrust washers 103 B secure the intermediate planet gears 103 F longitudinally and bushings 103 C are interposed between the input planet gears and the input planet pins 102 E. Bushings 103 C are interposed between the intermediate planet gears 103 F and the intermediate planet pins 103 E. Intermediate carrier roll pin 103 G secures the intermediate carrier 103 A to the intermediate planet pins to be driven by the planet gears. A thrust spacer 120 is located between the input and intermediate carriers. See FIG. 1A .
[0049] Still referring to FIGS. 1 and 1A , planet output carrier 104 A is secured with pins 104 G to the planet output pins 104 E. Output planet thrust washers 104 B secures the output planet gears 104 F against longitudinal movement. Output planet spacer 104 D separates the output planet needle roller bearings which are interposed between the interior of the output planet gears 104 F and the output pins 104 E to enable rotation of the output gears with respect to the output pins. Cover assembly 106 A is retained by the cover retaining ring 106 G. Cover thrust washer 106 B interengages output sun gear 111 driven by the intermediate carrier 103 A.
[0050] An Advanced 72V AC electric motor 107 A has an IP67 Protection Rating (waterproof to 1 meter) and drives splined disconnect shaft 109 which in turn drives the input sun gear 110 which in turn drives the input planet gears 102 F. The motor housing 107 A is, of course, affixed to the spindle 101 A as illustrated in FIG. 1C .
[0051] Still referring to FIG. 1 , an O-ring seal 107 C is interposed between the motor housing 107 A and spindle 101 A. An electric brake 108 A is affixed to the spindle 101 A with brake mounting bolts 199 and a seal 108 C resides between the brake and the spindle 101 A. The brake assembly includes a pressure plate 124 , a stationary plate 126 , and a friction plate 125 . Friction plate 125 is affixed to (splined 178 ) the motor shaft 141 / 141 A and rotates with the electric motor shaft 141 / 141 A. When the coil 130 in the housing 108 A is energized, the pressure plate 124 is pulled away from and disengages the friction plate 125 thus negating the brake. Springs 164 force the pressure plate 126 into engagement with the friction plate 125 which prohibits rotation of shaft 141 / 141 A. Bearing pre-load spring 108 E acts upon snap ring 108 D which resides in a recess in the inner bore of the brake 108 A. Motor sensor 128 is illustrated for use in connection with the speed control of the motor. A water seal 129 for the electrical wires (unnumbered) is also illustrated. The brake housing 108 A is mounted within the coil windings 123 of the electric motor. In this way space is saved and the overall length of the motor-gearbox-assembly is minimized.
[0052] The input planet gears 102 F are not as wide as the intermediate planet gears 103 F. The gear arrangement set forth in the preferred example as set forth in FIGS. 1 , 1 A and 1 B is superior to other arrangements because it is short in length, has high reduction, and is relatively impervious to dust and water.
[0053] The machine described herein includes a hybrid system containing a generator set for charging a bank of batteries. The batteries power all the machine functions including the wheel drive assemblies. When the battery reaches a certain discharge stage, the generator set will turn on and charge the batteries. This inherently smooths out the peaks and valleys of the power draw. As a result, the engine is only producing the power that the machine needs resulting in a considerably more efficient system with less emissions and quieter operation.
[0054] The invention is short enough in axial length as depicted in FIG. 1 that it can be put onto a steer wheel of a vehicle without protruding too far outside the vehicle undercarriage and without protruding too far inside the vehicle undercarriage. The power density of the invention is a result of using a high speed AC motor (6000 RPM max) with a very compact high reduction gearbox and brake. High speed motors are much more compact than low speed motors for a given horsepower. The assembly is also capable of operating in an outdoor environment. The motor gearbox assembly has been designed for IP67 rating (submersible up to 1 m of water).
[0055] The invention includes the following features. The compact arrangement of a high speed motor, high reduction gearbox, and electromagnetic brake minimize the utilization of space. Below are some additional features of this invention.
[0056] Packaging the high speed (1st and 2nd stages) planetary stages within the main wheel support bearings saves space. Traditionally the high speed gearing in a planetary wheel drive gearbox is toward the cover end. By moving the high speed stages within the bearings, the three planetary stages, input 102 F, intermediate 103 F and output fit 104 F in a shorter axial length than a traditional two planetary stage assembly. In addition, with the high speed gearing away from the cover, the noise transmission to the outside environment is reduced considerably.
[0057] The invention as set forth in FIGS. 1 , 1 A, 1 B and 1 C includes nesting the brake within the winding end turns 123 of the motor 107 A which saves space. Induction AC motors traditionally have long winding end turns that normally just occupy space. The first example utilizes this axial length by nesting the brake housing 108 A within the end turns. This results in about a 1″ reduction in axial length.
[0058] Using the brake 108 A as a motor support piece saves space. The brake provides bearing support for the motor shaft 141 / 141 A as well as seals the motor from gearbox assembly (which contains oil).
[0059] Exiting the leads 129 in a sealed fashion allows use in wet environments. Power (high current) leads and low current leads that communicate power and control signals outside the motor exit the motor enclosure without breaking a seal. The low current wires exit through an overmolded grommet.
[0060] In the event of a power loss the brake 108 A will engage. If the machine needs to be towed, it is not necessary for the operator to remove the motor to access and release the brake mechanically. The disconnect 113 / 109 allows release from the brake with relative ease. Disconnect rod 113 is pushed inwardly/leftwardly when viewing FIG. 1 which in turn pushes disconnect spline 109 against the force of spring 140 which releases the splined interconnection between disconnect 109 and the input sun gear which enables the wheel hub to turn freely thus moving the vehicle.
[0061] FIG. 2 is a cross-sectional assembly view 200 of another example of the motor-brake-gear reducer. Referring to the examples set forth in drawing FIG. 2 , an internal brake is mounted such that the coils 230 in the housing 208 A of the brake which attracts the plate 224 are located in proximity to the spindle 201 A. In the preferred example of FIGS. 1 , 1 A and 1 B, the internal brake is mounted such that the coil 230 is mounted substantially within the electric motor thus saving space.
[0062] FIG. 2A is an enlargement 200 A of a portion of FIG. 2 illustrating the input planet gears 202 F and intermediate planet gears 203 F. In the example set forth in FIGS. 2 and 2A it will be noticed that input planet gears 202 F are the same width as the intermediate planet gears 203 F.
[0063] Lip seal 201 B seals the gap between the spindle/input ring gear and the wheel hub 101 D. Main bearings 201 C support the wheel hub 201 D and output ring gear 201 E for rotation relative to the spindle 201 A. Bearing nut 201 F and set screw 201 G secure the bearings 201 C in place longitudinally.
[0064] FIG. 2A is an enlargement 200 A of a portion of FIG. 2 illustrating the input planet gears 202 F and intermediate planet gears 203 F. Input carrier 202 A along with thrust plates 202 B are illustrated in FIG. 2 . Input planet pins 202 E secure input planet gears 202 F to the input planet carrier 202 A. The input planet gears 202 F are secured to the input planet pin 202 E by plates 202 B. Bushings 203 C reside between the input planet gears and the pins 202 E. The input sun gear 210 is driven by splined 272 disconnect shaft 209 . Teeth of the input sun gear 210 intermesh 280 with teeth of the input planet gears 202 F driving the input planet gears. Retaining ring 212 retains the intermediate sun gear 216 .
[0065] Still referring to FIG. 2A , input planet gears 202 F include 35 carburized teeth and are driven by carburized input sun gear 210 having 19 teeth. Input thrust plates 202 B secure input planet gears 202 F to the input planet pins 202 E. Input/intermediate planet bushings 203 C support input planet gears 202 F and intermediate planet gears 203 F. Input planet pin retaining rings 202 G secure thrust plates 202 B to input planet pins 202 E. Similarly input thrust plates 203 B secure intermediate planet gears 203 F to the intermediate planet pins 203 E. Input carrier 202 A is driven by input planet pins 202 E and the input carrier is splined 273 to intermediate sun gear 216 . Intermediate sun gear 216 includes 19 carburized teeth and drives 281 intermediate planet gears which interengage and react against teeth of internal ring gear 288 of spindle 201 A. See FIG. 2A .
[0066] Intermediate sun retaining ring 212 retains input sun gear 202 F and input carrier 203 A. Snap ring 220 and output carrier 204 A retains the intermediate carrier 203 A.
[0067] FIG. 2 illustrates a brake 208 A. Inertia Dynamics Incorporated (hereinafter “IDI”) manufactures the spring applied-coil energized to release brake described herein. The IDI brake is adapted to be mounted to the spindle of the gear reducer. Energized coil 230 in the brake 208 A attracts ferromagnetic actuating plate 226 (sometimes referred to as the clapper) against the force of spring 264 and away from friction plate 225 to permit friction plate 225 to rotate with disconnect shaft 209 . When coil 230 is actuated plate 226 abuts body 208 A of the housing permitting rotation of the shaft 241 and of the shafts within the gearbox. Coil 230 is a direct current coil operable at 80 Volts direct current, 27 Watts. Wires supplying power to coil 230 are not illustrated in FIGS. 2 or 2 A.
[0068] Friction plate 225 includes friction material affixed thereto. Adhesive is used to affix the friction material to the friction plate. The friction material is located near the circumferential extent of the friction plate 225 . When the brake is applied, spring 264 urges the actuating plate 226 against the friction plate 225 and, in particular, against the friction material affixed to the friction plate which prohibits rotation of the shaft 241 . The brake is sealed 208 C against the spindle 201 A. See FIG. 2A to view seal 208 C.
[0069] Referring to FIG. 2 , motor 207 A has a generally cylindrically shaped tapered exterior. Motor 207 A is affixed to spindle 201 A with bolts which are not illustrated. Spring 240 bears upon disconnect shaft 209 to enable disassembly of the device through removal of the cover assembly 206 A, cover thrust washer 206 B, and cover retaining ring 206 G. Once the cover 206 A, the thrust washer 206 B, and cover retaining ring 206 G are removed, internal disconnect rod 213 may be pushed inwardly and the cover may be reversed or flipped and reinstalled pushing disconnect rods 213 , 209 leftwardly to disengage the motor and the gearbox from each other. Disconnect rod 213 is ordinarily used to support output sun gear. Motor shaft 241 is supported by bearings 242 at the generally leftward end of the motor and is supported by bearings 290 at the generally rightward end of the motor. Bearings 290 reside between stationary brake housing 208 A and shaft 241 permitting rotation of the shaft with respect to the bearing housing. Brake 208 A is affixed with bolts 261 to spindle 201 A. Motor 207 A is sealed 208 C with O-rings to prevent the intrusion of water or dust at the joint of the spindle and motor.
[0070] Brake 208 A resides in the diametrical bore 296 of one end of the spindle 201 A. Bearings 290 are tensioned and retained in place by spring 208 E operable between ring 208 D residing in a groove in an inner diametrical bore of the brake and the bearing 290 . Spring 208 E urges bearing 290 against a shoulder on the exterior of the shaft 241 . Spindle 201 A includes intermediate ring gear 288 .
[0071] Input sun gear 210 is carburized and has 19 teeth. Input sun gear 210 is splined 272 to the disconnect shaft 209 . Input carrier 202 A is splined 273 to the intermediate sun gear 116 which in turn drives intermediate planet gears 203 F. It will be noticed that FIG. 2 depicts input planet gears 202 F which are as equally wide as the intermediate planet gears 203 F which results in positioning the first and second planetary stages within ring gear 288 within spindle 201 A. This saves axial space within the gearbox while effectively and efficiently transmitting power and torque.
[0072] Input seal 208 F and brake O-ring 208 C seal the gearbox from the motor preventing unwanted lubricating oil in the motor. Wheel hub 101 D is affixed to output ring gear 201 E with bolts 201 M. Main lip seal 201 B seals between the output ring gear 201 E, hub 201 D, and the spindle/input ring gear 201 A. Main bearings 201 C interengage wheel hub 201 D and spindle 201 A enabling rotation of the wheel hub 201 D with respect to the spindle 201 A which is affixed to the vehicle and is not rotatable. Bearing nut 201 F and set screws 201 G ensure that bearings 201 C are secured against the spindle 201 A. Seals such as O-ring seal 218 are used in the gearbox where necessary.
[0073] Intermediate gears 203 F drive intermediate carrier 203 A which is splined 274 to output sun gear 211 . Carburized output sun gear 211 includes 25 teeth and drives 282 output planet gears 204 F which interengage teeth 288 A of the output ring gear 201 E. There are four output planet gears. Output carrier 204 A positions the output planet gears 204 F and output planet pins 204 E apart from the first (input stage) and the second (intermediate stage) and within the output ring gear 201 E.
[0074] Output planet carrier 204 A is stationary. Output planet gears 204 F intermesh 288 A with teeth of the output internal ring gear causing it to rotate and drive a wheel (not shown) affixed by studs 201 M and nuts (not shown). Output planet thrust washers/plates 204 B restrict the side to side movement of the output planet gears. Output planet spacer 204 D and output planet needle rollers 204 C support the output planet gears and enable rotation of the output planet gears with respect to the output planet roll pins 204 E. Output planet pins 204 G secure the output planet roll pins 204 E to the stationary output planet carrier.
[0075] An intermediate carrier 203 A interengages the output sun gear 211 . Intermediate planet thrust plates 203 B secure the intermediate planet gears 203 F longitudinally. Bushings 203 C are interposed between the input planet gears 202 F and the input planet pins 202 E. Bushings 203 C are interposed between the intermediate planet gears 203 F and the intermediate planet pins 203 E.
[0076] Planet output carrier 204 A is secured with pins 204 G to the planet output pins 204 E. Output planet thrust washers/plates 204 B secures the output planet gears 204 F against longitudinal movement. Output planet spacer 204 D separates output planet needle roller bearings which are interposed between the interior of the output planet gears 204 F and the output pins 204 E to enable rotation of the output gears with respect to the output pins. Cover assembly 206 A is retained by the cover retaining ring. Cover thrust washer 206 B interengages output sun gear 211 driven by the intermediate carrier 203 A.
[0077] A Sauer AC electric motor 207 A drives splined disconnect shaft 209 which in turn drives the input sun gear 210 which in turn drives the input planet gears 202 F. The motor housing 207 A is, of course affixed to the spindle 201 A.
[0078] The examples of FIGS. 1 and 2 are different. FIG. 2 illustrates a spacer 269 and an “L” shaped sleeve between motor 207 A and forged spindle/input ring gear 269 in an opening in the large spacer/cover 269 S. FIG. 1 utilizes a different motor 107 A which is IP 67 rated. It will be noticed that brake 208 A is housed partially within the diametrical bore 296 in the end of spindle 201 A. In FIG. 1 plates 124 , 126 and friction plate 125 are housed within the diametrical bore 196 in the end of spindle 101 A and housing 108 A primarily resides between windings 123 of the motor and the motor shaft 141 A. FIG. 1 also employs a narrow input planet gear 102 F which together with the reverse orientation of the brake provides a motor-brake-reducer combination which is shorter in language. The advantage of the narrower input stage is that the intermediate stage gearing can be wider. The intermediate stage gearing is wider in the first example. prototypes and was causing premature failures in our testing. Spindle 101 A and spindles 201 A have the same profiles.
[0079] FIG. 2 illustrates a motor-brake-reducer combination which is longer than the motor-brake-reducer combination of FIG. 1 due to the orientation of the brake outside the motor windings 223 and the wider input planet gear 202 F. Because the brake does not fit within the motor, a spacer 269 and an “L” shaped sleeve between motor 207 A and forged spindle/input ring gear 269 reside in an opening in the large spacer/cover 269 S near a wiring harness leading to the exterior of the motor. FIG. 2 illustrates the spacer 269 and the “L” shaped sleeve 269 A extending longitudinally along the axis of the device about the thickness of the pressure plates 224 , 226 and the friction 225 .
[0080] FIG. 3 is a cross-sectional assembly view 300 of another example of the motor-brake-gear reducer which is identical in many respects to the example set forth in FIGS. 2 and 2A . Reference numerals in the 200 series in FIGS. 2 and 2A denote the same structure as reference numerals in the 300 series in FIGS. 3 , 3 A and 3 B except where discussed herein. FIG. 3A is an enlargement 300 of a portion of FIG. 3 illustrating the input planet gears 301 F and intermediate planet gears 303 F. FIG. 3A is included for completeness and is identical to FIG. 2 . FIG. 3 illustrates a motor-brake-reducer combination which is slightly longer than the example illustrated in FIG. 1 due to the orientation of the brake outside the motor windings 323 and due to the use of the Sauer 207 A motor. Because the brake does not fit within the motor 307 A, an integral spacer 369 and an “L” shaped sleeve 369 A resides between motor 307 A and forged spindle/input ring gear 369 and an opening in the large spacer/cover 369 S near a wiring harness leading to the exterior of the motor exists. Motor 307 A is affixed to spindle 101 A with bolts which are unnumbered in FIG. 3B . FIG. 3 illustrates the integral spacer 369 and the “L” shaped sleeve 369 A extending longitudinally along the axis of the device about the thickness of the pressure plates 324 , 326 and the friction 325 . FIG. 3B is an outside perspective view of the example illustrated in FIGS. 3 and 3A . A Sauer AC electric motor 307 A drives splined disconnect shaft 309 which in turn drives the input sun gear 310 which in turn drives the input planet gears 302 F. The motor housing 307 A is, of course affixed to the spindle 301 A.
[0081] FIG. 4 is a cross-sectional assembly view 400 of another example of the motor-brake-gear reducer. FIG. 4A is an enlargement 400 of a portion of FIG. 4 illustrating a portion of the brake 408 A. FIG. 4B is an outside perspective view 400 B of the example illustrated in FIGS. 4 and 4A . FIG. 4 is a cross-sectional assembly view 400 of another example of the motor-brake-gear reducer which is identical in many respects to the example set forth in FIGS. 2 and 3 . Reference numerals in the 200 and 300 series in regard to the respective FIGS. 2 , 2 A and 3 , 3 A and 3 B and denote the same structure as reference numerals in the 400 series in FIGS. 4 , 4 A and 4 B except where discussed herein. FIG. 4A is an enlargement 400 of a portion of FIG. 4 illustrating the input planet gears 401 F and intermediate planet gears 403 F. FIG. 4A is included for completeness and is identical to FIGS. 2A and 3A . FIG. 4 illustrates a motor-brake-reducer combination which is slightly longer than that shown in FIG. 1 due to the orientation of the brake 408 A outside the motor windings 423 and the Danaher motor 408 A. Because the brake does not fit within the motor, a spacer 469 and an “L” shaped sleeve 469 A reside between motor 407 A and forged spindle/input ring gear 401 A. Motor 407 A is affixed to spindle 401 A with bolts which are unnumbered in FIG. 4B . An opening in the large spacer/cover 469 S near a wiring harness leading to the exterior of the motor is also shown but is unnumbered. FIG. 4 illustrates the integral spacer 469 and the “L” shaped sleeve 469 A extending longitudinally along the axis of the device and is about the same as the thickness of the pressure plates 424 , 426 and the friction 425 . FIG. 4B is an outside perspective view 400 B of the example illustrated in FIGS. 4 and 4A . A Danaher AC electric motor 407 A drives splined disconnect shaft 409 which in turn drives the input sun gear 410 which in turn drives the input planet gears 402 F. The motor housing 407 A is, of course, affixed to the spindle 401 A.
[0082] The operation of FIGS. 2 , 3 and 4 of the gear set and the brake is the same as described in connection with the example of FIG. 1 except as described herein. FIG. 1 is the preferred example and due to the geometry of the various components and their arrangement is the most compact and efficient motor-brake-gear reducer.
[0083] The overall length of the example of FIG. 1 from left side motor covering 179 to the right side motor covering 179 A is approximately 16 inches. Similarly, the overall length of the example of FIGS. 2 and 3 from left side motor covering 279 , 379 to the right side motor covering 279 A, 379 A is approximately 16.3 inches. Similarly, the overall length of the example of FIG. 4 from the left side motor covering 479 to the right side motor covering 479 A is approximately 16.6 inches.
[0084] A Danaher AC electric motor 407 A drives splined disconnect shaft 409 which in turn drives the input sun gear 410 which in turn drives the input planet gears 402 F. The motor housing 407 A is, of course affixed to the spindle 401 A. All of the motors 107 A, 207 A and 307 A are 6 horsepower motors.
[0085] In general, all gearing, bearings, planet gear shafts, are made of carburized steel while the carriers and housings are made from ductile iron or steel. The input stage carrier is made out of through hardened steel. The spindle is made from gray iron/forged steel/steel alloy and the motor housings are aluminum.
[0086] In general there are three input planets, three intermediate planets, and three or four output planets depending on the gearbox rating required for the application. Other configurations as to the number of gears for each stage may be employed.
REFERENCE NUMERALS
[0000]
100 —cross-sectional view of torque hub with brake located partially within the electric motor
100 A—enlargement of a portion of FIG. 1
100 B—enlargement of a portion of FIG. 1A
100 C—enlargement of a portion of FIG. 1C
101 A—forged spindle/input ring gear
101 B—main lip seal
101 C—series main bearings
101 D—hub
101 E—output ring gear
101 F—series bearing nut
101 G—bearing nut set screw
101 M—studs
102 A—input carrier
102 B—input thrust plates
102 D—input planet bushing
102 E—input planet pins
102 F—input planets, 35t, carburized
102 G—input planet pin retaining rings
103 A—double wall intermediate carrier
103 B—intermediate planet thrust washers
103 C—input/intermediate planet bushings
103 E—intermediate planet pins
103 F—intermediate planet gear
103 G—intermediate carrier roll pin
104 A—4-planet output carrier
104 B—output planet thrust washer
104 C—output planet needle rollers
104 D—output planet spacer
104 E—output planet pins
104 F—output planet gear, 46t
104 G—output planet roll pins
106 A—cover assembly
106 B—cover thrust washer
106 G—cover retaining ring
107 A—Advanced 72V AC motor, IP67 protection rating
107 C—motor O-ring
108 A—electric brake
108 C—brake O-ring
108 D—brake retaining ring
108 E—bearing pre-load spring
108 F—input seal
109 —splined disconnect shaft
110 —input sun gear, 19t, carburized
111 —output sun gear, 25t, carburized
112 —intermediate sun retaining ring
113 —internal disconnect rod
116 —intermediate sun gear, 19t, carburized
118 —output ring gear o-ring
120 —thrust spacer between input & intermediate carrier
123 —electric motor winding end turns
124 —pressure plate
125 —friction plate
125 A—friction material affixed by adhesive to friction plate
126 —actuating plate
128 —motor speed controls
129 —water seal for electrical wires
130 —coils in brake
140 —thrust spring
141 —motor shaft
141 A—motor shaft
142 —bearings
160 —threaded bolt for affixing the brake to the forged spindle/input ring gear
161 —spacer between electromagnetic coil and the pressure plate, one of three
162 —interengagement of the pressure plate against the forged spindle/input ring gear
163 —passageway in the friction plate 125
163 A—threaded interconnection with spindle 101 A
163 P—passageway in ferromagnetic plate 126
163 Q—passageway in plate 124
164 —spring, one of three
169 —gap between inner coil housing 108 A and inner plate 126 when coil is de-energized
171 —spline interconnecting motor shaft and disconnect shaft
172 —spline interconnecting disconnect shaft 109 /input sun gear 110
173 —spline interconnecting input carrier 102 A
174 —spline interconnecting intermediate carrier 103 A and output sun 111
178 —splined
179 , 279 , 379 , 479 —left side motor covering
179 A, 279 A, 379 A, 479 A—right side motor covering
180 —intermeshing of input sun gear and input planet gears
181 —intermeshing of intermediate input sun 116 and intermediate planet gears 103 F
182 —intermeshing of output sun and output planet gears
188 —internal ring gear of spindle 101 A
189 —bushing operating between disconnect rod 113 and output sun gear 111
190 —bearings supporting motor shaft 141 A
196 —diametrical bore in end of spindle 101 A
197 —space between end of the motor windings 123 and motor shaft 141 / 141 A
199 —bolt affixing the body of the brake 108 A, the spacer and the plate 124 to the spindle 101 A
200 —cross-sectional view of torque hub with brake
200 A—enlargement of a portion of FIG. 2
201 A, 301 A, 401 A—spindle/input ring gear (forging)
201 B, 301 B, 401 B—main lip seal
201 C, 301 C, 401 C—main bearings
201 D, 301 D, 401 D—hub
201 E, 301 E, 401 E—output ring gear
201 F, 301 F, 401 F—bearing nut
201 G, 301 G, 401 G—bearing nut set screw
201 M, 301 M, 401 M—studs
202 A, 302 A, 402 A—input carrier
202 B, 302 B, 402 B—input thrust plates
202 E, 302 E, 402 E—input planet pins
202 F, 302 F, 402 F—input planets, 35t, carburized
202 G, 302 G, 402 G—input planet pin retaining rings
203 A, 303 A, 403 A—double wall intermediate carrier
203 B, 303 B, 403 B—intermediate planet thrust plates
203 C, 303 C, 403 C—input/intermediate planet bushings
203 E, 303 E, 403 E—intermediate planet pins
203 F, 303 F, 403 F—intermediate planet gear
203 G, 303 G, 403 G—intermediate carrier roll pin
204 A, 304 A, 404 A—4 planet output carrier
204 B, 304 B, 404 B—output planet thrust washers/plate
204 C, 304 C, 404 C—output planet needle rollers
204 D, 304 D, 404 D—output planet spacer
204 E, 304 E, 404 E—output planet pins
204 F, 304 F, 404 F—output planet gear, 46t
204 G, 304 G, 404 G—output planet roll pins
206 A, 306 A, 406 A—cover assembly
206 B, 306 B, 406 B—cover thrust washer
206 G, 306 G, 404 G—cover retaining ring
207 A, 307 A, 407 A—Sauer motor
208 A, 308 A, 408 A—electric brake
208 C, 308 C, 408 C—brake O-ring
208 D, 308 D, 408 D—brake retaining ring
208 E, 308 E, 408 E—bearing pre-load spring
208 F, 308 F, 408 F—input seal
208 G, 308 G, 408 G—standoff/interconnection between outer plate 226 and electric brake
208 A/coil 230
209 , 309 , 409 —splined disconnect shaft
210 , 310 , 410 —input sun gear, 19t, carburized
211 , 311 , 411 —output sun gear, 25t, carburized
212 , 312 , 412 —intermediate sun retaining ring
213 , 313 , 413 —internal disconnect rod
216 , 316 , 416 —intermediate sun gear, 19t, carburized
218 , 318 , 418 —output ring gear O-ring
220 , 320 , 420 —thrust spacer between input & intermediate carrier
221 , 321 , 421 —disconnect retaining ring
222 , 322 , 422 —disconnect washer, outside diameter 0.524; inside diameter, 0.286; thickness, 0.047;
223 , 323 , 423 —electric motor winding end turns
224 , 324 , 424 —pressure plate
225 , 325 , 425 —brake friction
226 , 326 , 426 —plate
230 , 330 , 430 —coil in brake
240 , 340 , 440 —spring
241 , 341 , 441 —motor shaft
242 , 342 , 442 —motor bearing
261 —spacer between electromagnetic coil and the pressure plate, one of three
264 , 364 , 464 —spring
269 , 469 —extension of forged spindle/input ring gear (forging)
269 A, 369 A, 469 A—“L” shaped sleeve
269 S, 369 S, 469 S—large spacer/cover
272 , 372 , 472 —spline interconnecting disconnect shaft 209 / 309 / 409 input sun gear 210 / 310 / 410
273 , 373 , 473 —spline interconnecting input carrier 202 A
274 , 374 , 474 —spline interconnecting intermediate carrier 203 A/ 303 A/ 404 A and output sun 211 / 311 / 411
274 A, 374 A, 474 A—spline interconnecting output carrier with spindle
281 , 381 , 481 —intermeshing of intermediate input sun and intermediate planet gears
288 , 388 , 488 —internal ring gear of spindle 201 A/ 301 A/ 401 A
290 , 390 , 490 —bearings supporting motor shaft
296 , 396 , 496 —internal diameter of spindle 201 A/ 301 A/ 401 A
300 —cross-sectional view of torque hub
300 A—enlargement of a portion of FIG. 3
300 B—perspective view of the torque hub
369 —integral extension of the spindle
400 —cross-sectional view of torque hub
400 A—enlargement of a portion of FIG. 4
400 B—perspective view of the torque hub
[0250] The invention has been set forth by way of example. Those skilled in the art will readily recognize that changes may be made to the invention without departing from the spirit and the scope of the appended claims.
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A compact gear reducer electric motor assembly with an internal brake disclosed and claimed wherein a high speed electric motor is interconnected with a gear reducer having substantial gear reduction. The assembly includes a spindle, a brake mounted substantially within said high speed electric motor and operable against a spring biasing said brake into engagement with ground. The brake is electrically actuated to permit transmission of energy to the gear reducer. The gear reducer includes an input, intermediate and output planetary stages. The input and intermediate stages residing within the spindle, and, the output planetary stage drives an output ring gear. Releasing means for releasing the output ring gear from the brake allowing rotation thereof.
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CROSS-REFERENCE TO RELATED PATENT APPLICATION
This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application. No. 61/213,539, filed on Jun. 18, 2009 in the U.S. Patent and Trademark Office, the entire disclosure of which is hereby incorporated by reference.
FIELD OF THE INVENTION
The present application relates to the areas of software encryption, licensing and security. Particularly, the present invention provides a system, apparatus and method for altering the generation and validation of cryptographic and/or license verification keys using a configurable combination code.
BACKGROUND OF THE INVENTION
Traditionally, application software use license verification systems for controlling use of application software and other protected content employing a key or key-pair that is generated and, at some point, used in protocols whose purpose is typically, but not exclusively, to verify ownership of a software or content license.
These key-based systems are frequently compromised by illegal key generator software applications produced by software crackers. Frequently referred to as “key-gens,” these programs are capable of mimicking the methods used to create license keys. These illegal keys can then be supplied to the application during product activation resulting in theft of the software license.
Traditionally, illegal “key-gen” applications typically rely on analyzing an installation key (i.e. product key) that is either entered manually or scraped from the system. The installation key is analyzed and a correctly paired activation key is generated. These applications are dependent on reproducing the methods that a legitimate system uses to produce these key pairs.
A fundamental technological issue when combating these key-gens is that the underlying primary verification methods and protocols are embedded within application source code. Modifying application logic to thwart illegal key-gens (that is, in order to generate new valid key pairs) can take months or potentially years on larger applications.
Because the effort to design and develop new key generation and license verification protocols is greater than the effort and time to reverse engineer them, the hacker community is capable of rapidly compromising these methods and systems, typically within weeks of a new release of software.
Traditional systems are rigid, difficult and time consuming to change. Like an old iron lock that must be re-forged to change the key, once the method to generate the key has been discovered, it takes far too long to address the problem of re-securing the system.
What is needed is a system that can rapidly alter the structure and methods used to generate the keys and re-secure the system at a rate that is equivalent to or better than the rate at which illegal key generators can compromise those structures and methods.
Illustrative embodiments of the present invention address at least the drawbacks associated with conventional system and provide many advantages.
SUMMARY OF THE INVENTION
As noted above, exemplary embodiments of the present invention address at least the above problems and/or disadvantages, and provide at least the advantages described below.
Exemplary embodiments of the present invention provide a system, method and apparatus that can rapidly alter the structure and methods used to generate the keys and re-secure the system at rate that is equivalent to or better than the rate at which illegal key generators can compromise the keys.
Exemplary embodiments of the present invention provide for a method, system and apparatus for generating and/or utilizing a mangled license key for invalidating an illegally produced key in a computer license validation system by generating a combination key that utilizes a subset of key obfuscation algorithms of a master set or collection of algorithms to encode an installation key, encrypting the installation key using the combination key, thereby producing a mangled license key, and decoding the mangled license key to produce the installation key.
Exemplary embodiments of the present invention provide a system, method and apparatus for invalidating the illegal keys produced illegally by illegal key generator software application programs by altering both the structure of the keys and the methods used to generate the keys. A changeable combination code is used to select a subset of key obfuscation algorithms from a larger master-set. The original key is then processed by this subset of algorithms producing a key that is incompatible with the illegal key generator.
Exemplary embodiments of the present invention provide a system, method and apparatus for altering a license key system to invalidate a compromised key without changing the fundamental construction of the license key system.
Exemplary embodiments of the present invention provide additional benefits relating to systems that use cryptographic data other than activation/installation key pairs.
Further, exemplary embodiments of the present invention provide for a system, method and apparatus for license key permutation in the context of using installation/activation key pairs.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other exemplary features, aspects and advantages of the present invention will become more apparent from the following detailed description of certain exemplary embodiments thereof when taken in conjunction with the accompanying drawings in which:
FIG. 1 is a schematic block diagram that illustrates an overview of the entire key permutation process within the context of product license activation method, system and apparatus of the present invention, according to an exemplary embodiment.
FIG. 2 is a schematic block diagram that illustrates how selection of a combination code relates to (for example, influences) the algorithms selected for employment during encoding and decoding within the context of product license activation method, system and apparatus of the present invention, according to an exemplary embodiment.
FIG. 3 is a schematic block diagram that illustrates interaction in a system using a static set of algorithms used to generate a mangled key within the context of product license activation method, system and apparatus of the present invention, according to an exemplary embodiment.
FIG. 4 is a schematic block diagram that illustrates how selection of a combination code relates to (for example, influences) the algorithms selected for employment during encoding and decoding within the context of product license activation method, system and apparatus of the present invention, according to an exemplary embodiment.
FIG. 5 is a schematic block diagram that illustrates how selection of a combination code relates to (for example, influences) the algorithms selected for employment during encoding and decoding within the context of product license activation method, system and apparatus of the present invention, according to an exemplary embodiment of the present invention.
FIG. 6 is a flow diagram that illustrates an overview of the method for utilizing a mangled installation key for invalidating an illegally produced installation key in a computer license validation system, according to an exemplary implementation of the present invention.
FIG. 7 is a schematic block diagram that illustrates an apparatus for generating a mangled license installation key for invalidating an illegally produced key, according to an exemplary embodiment of the present invention.
FIG. 8 is a schematic block diagram that illustrates a computer license validation system for generating a mangled license installation key for invalidating an illegally produced key, according to an exemplary embodiment of the present invention.
Throughout the drawings, like reference numerals will be understood to refer to like elements, features and structures.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
The matters exemplified in this description are provided to assist with a comprehensive understanding of exemplary embodiments of the present invention described with reference to the accompanying drawing figures. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the exemplary embodiments described herein can be made without departing from the scope and spirit of the present invention. Also, descriptions of well-known functions and constructions are omitted for clarity and conciseness. Likewise, certain naming conventions, labels and terms as used in the context of the present disclosure are, as would be understood by skilled artisans, non-limiting and provided only for illustrative purposes to facilitate understanding of certain exemplary implementations of the embodiments of the present invention.
FIGS. 1-8 illustrate exemplary embodiments of the present invention that provide for a method, system and apparatus for generating and/or utilizing a mangled installation key for invalidating an illegally produced installation key in a computer license validation system by generating a combination key to utilize a subset of key obfuscation algorithms to encode an installation key, encrypting the installation key in accordance with the combination key, thereby producing a mangled installation key, and then decoding the mangled installation key to produce the installation key.
FIG. 1 is a schematic block diagram that illustrates an overview of the key permutation process within the context of product license activation method, system and apparatus of the present invention, according to an exemplary embodiment. For example, when an application 1 generates an installation key 2 , it passes it to the encoder 3 for processing. A “combination key” 4 is generated by passing seed data 5 (for example, seed data can be any data that is known, generated or stored by the application, such as a hardware identifier, the original activation key or installation key) through a series of obfuscation algorithms (1 . . . n). The output of each algorithm is chained to the input of the next creating a complex code path 6 . An algorithm can be any algorithm such as a hashing algorithm, mathematical algorithm or any other algorithm, provided that the algorithm produces consistent results. Some exemplary obfuscation algorithms are:
Hashing the input using an array of bytes;
Using XOR with each byte of the input or an external buffer;
Reverse or jumble the bits in the key using a known pattern;
Run the input through an encryption algorithm;
Hashing the input using any algorithm (i.e. MD5, SHA1, etc), among other obfuscation algorithms.
Once generated, the combination key is used to encrypt 7 the original installation key and produce a new permutation of the key which can be referred to as a mangled key or mangled installation key 8 .
According to exemplary implementations of the present invention, the obfuscation algorithms used during the combination key generation phase are a sub-set of a larger collection of algorithms, all of which are known to the decoder (e.g., decoder 11 in FIG. 1 ) and are all stored at a server (e.g. key server 9 in FIG. 1 ) to allow it to generate an activation code corresponding to the installation code when license verification is desired. This allows the selection of a sub-set of the algorithms during the key obfuscation phase using a combination code which specifies the obfuscation algorithms to employ. Alternatively, the sub-set of algorithms can be selected and then the combination code generated based on those selected algorithms. Changing the combination code changes the selection of algorithms used to create the mangled installation key resulting in an output unique to the given combination code.
FIG. 2 is a schematic block diagram that illustrates a combination selection according to an exemplary implementation of the present invention, where any number or combination of algorithms may be used, order is not important, and each algorithm may preferably only be used once within a combination, so the formula to calculate the number of possible key combinations is:
∑
r
=
1
n
n
!
r
!
(
n
-
r
)
!
where n is the number of algorithms and r is the number selected. With modest obfuscation algorithms such as 16 algorithms, 65535 unique combinations are possible. Because the combination key is generated dynamically, it is not possible to use static analysis to determine how the installation key was encrypted (e.g., mangled) to thwart hackers from illegally obtaining and using the installation key. Furthermore, because the combination code is actually specifying the algorithms to employ, it forces the process of key generation through a path of execution unique to the given code. This, in turn, means that for any new combination, a software cracker would be forced to do an active re-analysis of the key generation process in order to produce an illegal key-gen for that code. This makes it difficult for the cracker to reverse engineer but easy for a legitimate system because all that is required is a change to the combination code.
With continued reference to FIG. 1 , when a key-server 9 needs to generate a key pair, it passes the mangled key 10 to the decoder 11 along with the combination code 12 . The decoder parses the combination code 12 to determine which algorithms were used to generate the combination key. The combination code may be supplied through various sources such as via an end user 13 , an external system 14 or by obfuscation 15 (for example, embedded in the application code), or passing it with the mangled key. The combination code is then used to decrypt and recover the original installation key. The key-server 9 then uses the usual method to create a correctly paired product activation key.
According to exemplary embodiments of the present invention, the key encoder may work in a static, dynamic or hybrid implementation employing both static and dynamic encoding.
According to an exemplary embodiment of the present invention, in a static implementation, the encoder is compiled using a hard coded sub-set of algorithms. The combination code in this case could be a static value well-known by the decoder. This has the advantage that there is no need to transmit the combination code and only a sub-set of the algorithms need to be exposed on a target system, making it impossible to perform any local analysis on the entire set of the collection of algorithms used by the server 9 .
FIG. 3 is a schematic block diagram that illustrates a static encoder which comprises a fixed set of obfuscation algorithms 16 (e.g., a subset of the collection of algorithms used by the server 9 ) that are hard-coded and compiled into the application code, according to an exemplary embodiment of the present invention. These algorithms generate the combination key 17 that is used to encrypt 18 the original key 19 producing a mangled key 20 . The decoder 11 must be supplied a combination code that matches the hard-coded algorithms employed in the static encoder. If an illegal key-gen program is discovered, a new version of the static encoder must be released that implements a different combination of all or some of the subset of hard-coded obfuscation algorithms 16 compiled into the application code.
According to an exemplary embodiment of the present invention, in a dynamic implementation, the encoder can implement preferably the entire set of the collection of obfuscation algorithms used by the server 9 . These algorithms are selected dynamically based on a given combination code. This method has the advantage that new combinations can be created without a software release (e.g., the combination can be communicated a different way to the decoder than compiled, for example, in the application code) but at the cost of exposing more of the system for analysis by a hostile party.
FIG. 4 is a schematic block diagram that illustrates a dynamic encoder implementing a richer set of obfuscation algorithms 21 than a static encoder (e.g., in FIG. 3 ), according to an exemplary embodiment of the present invention. During the encoding phase, a combination code 22 is supplied that specifies the algorithms to employ ( 23 ) when generating the combination key ( 24 ). The combination key ( 24 ) is used to encrypt ( 26 ) the given original key ( 27 ) producing a mangled key ( 28 ) that is unique to the given combination code ( 22 ).
According to an exemplary embodiment of the present invention, a hybrid implementation can use a combination of hard-coded algorithms and a dynamically selected set. This may provide the best balance between security and flexibility.
According to an exemplary embodiment of the present invention, if an illegal key-gen program is discovered, a different combination code is supplied to force the creation of an incompatible mangled key ( 28 ).
According to an exemplary embodiment of the present invention, FIG. 5 illustrates that, at some point, the original key is recovered so it can be used during a normal process of key-pair generation, encryption, verification or other key use typical of a cryptographic or secure system. There may be multiple versions of static and dynamic encoders that have been built for different usage scenarios or to combat illegal key-gens. The decoder includes every obfuscation algorithm ( 30 ) that is employed in these encoders.
Every algorithm in use has a unique identifier that is encoded in the combination code ( 31 ). This allows the decoder to determine which specific set of obfuscation algorithms ( 30 ) were employed in the generation of the mangled key ( 32 ). The correct set of algorithms is selected based on information from the combination code ( 31 ) and a combination key ( 33 ) is generated. The combination key ( 33 ) is used to decrypt ( 34 ) the mangled key ( 32 ) and recover the original key ( 35 ). Once the original key has been recovered, the system may use it normally in any cryptographic or other secure process.
FIG. 6 illustrates an exemplary embodiment of the present invention providing a method 600 for utilizing a mangled installation key for invalidating an illegally produced key in a computer license validation system, the method comprising the steps of obtaining an installation key 601 , selecting a subset of key obfuscation algorithms from a master set of key obfuscation algorithms based on a combination code 602 , generating a combination key by processing seed data with the subset of key obfuscation algorithms 603 , and generating the mangled installation key by processing the installation key with the combination key 604 , wherein the mangled installation key is different than the illegally produced key, and wherein the method is computer-implemented.
FIG. 7 illustrates an exemplary embodiment of the present invention providing a computer 706 , 707 implemented apparatus 700 generating a mangled installation key for invalidating an illegally produced key, the apparatus comprising an application unit for generating or obtaining an installation key 701 , a key server for generating a product activation key and installation key pair 702 , an encoding unit for generating a combination key by selecting a subset of key obfuscation algorithms from a master set of key obfuscation algorithms based on a combination code 703 , an encryption unit for encrypting the installation key using the combination key and thereby, producing a mangled installation key 704 , and a decoding unit for decoding the mangled installation key, thereby producing a result installation key, and further comprising selecting the subset of key obfuscation algorithms from the master set of key obfuscation algorithms provided at the decoding unit, based on the combination code 705 , wherein the mangled installation key is a varied permutation of the installation key.
FIG. 8 illustrates an exemplary embodiment of the present invention providing a computer license validation system 800 for generating a mangled installation key for invalidating an illegally produced key, the system comprising an encoder for encoding and producing the mangled installation key by processing an installation key with a subset of key obfuscation algorithms selected from a master set of key obfuscation algorithms based on a combination code 801 , and a decoder for decoding the mangled installation key by processing the mangled installation key with a subset of key obfuscation algorithms selected from a master set of key obfuscation algorithms provided at the decoder based on a combination code, thereby producing a result installation key 802 .
Further, FIG. 8 illustrates an exemplary embodiment of the present invention providing a system 800 comprising a computer processor 803 for executing a computer program embodied on a computer readable storage medium, the computer program executing instructions for generating a mangled installation key for invalidating an illegally produced key.
The above-described exemplary embodiments of an apparatus, system and method in computer-readable media include program instructions to implement various operations embodied by a computer. The media may also include, alone or in combination with the program instructions, data files, data structures, and the like. The media and program instructions may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of computer-readable media include magnetic media such as hard disks, floppy disks, and magnetic tape; optical media such as CD ROM disks and DVD; magneto-optical media such as optical disks; and hardware devices that are specially configured to store and perform program instructions, such as read-only memory (ROM), random access memory (RAM), flash memory, and the like. The media may also be a transmission medium such as optical or metallic lines, wave guides, and so on, including a carrier wave transmitting signals specifying the program instructions, data structures, and so on. Examples of program instructions include both machine code, such as produced by a compiler, and files containing higher level code that may be executed by the computer using an interpreter. The described hardware devices may be configured to act as one or more software modules in order to perform the operations of the above-described embodiments of the present invention.
Although exemplary embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions, and substitutions are possible, without departing from the scope of the present invention. Therefore, the present invention is not limited to the above-described embodiments, but is defined by the following claims, along with their full scope of equivalents.
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A system and method of dynamically altering the encoding, structure or other attribute of a cryptographic key, typically a license activation key, to render useless keys that have been created by illegal key generation “cracks”. An encoding/decoding engine provides a plurality of key obfuscation algorithms that may alter the structure, encoding or any other attribute of a given key. A changeable combination code is supplied to the encoding/decoding engine that specifies a subset of the algorithms to apply during the encoding or decoding phase. The encoding engine is used during key generation and the decoding engine used during key usage. The same combination code must be used during decoding as was used during encoding to recover the original key or a valid key will not be recovered. Thus, a system can be rapidly re-keyed by selecting a new combination of encoding/decoding algorithms. The selection of algorithms comprises a combination code. The new combination code will result in keys that are incompatible with any existing illegal key generators.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to Japanese Patent Application No. 2011-170622, filed Aug. 4, 2011, the disclosure of which is hereby incorporated by reference in its entirety.
BACKGROUND
The present disclosure relates to a sewing machine that can perform sewing of an embroidery pattern, an embroidery data creation device that creates data for sewing an embroidery pattern, and a non-transitory computer-readable medium that stores an embroidery data creation program.
A sewing machine is known that can sew an embroidery pattern based on a design that a user has selected. An embroidery data creation device is also known that creates embroidery data for sewing an embroidery pattern. Specifically, the embroidery data creation device is also known that acquires a design that a user has selected. The embroidery data creation device creates embroidery data for sewing the acquired design as an embroidery pattern. The embroidery data creation device can recognize characters in the acquired design and convert them into other characters of a different style. The embroidery data creation device is thus able to create embroidery data for sewing an embroidery pattern of a design that contains the characters of the different style.
SUMMARY
Demand has arisen to have characters of a particular style acquired in advance by a sewing machine, to have a character string created by combining the acquired characters as the user desires, and to have an embroidery pattern of the character string sewn by the sewing machine. The characters of a particular style may be characters in a handwritten style, for example. The known devices described above are not able to acquire characters of a particular style in advance. Therefore, cases may occur in which the embroidery data for sewing a character string that includes characters of a particular style cannot be created.
There may also be cases in which, after the embroidery data are created based on a character string that includes characters of a particular style, and that is acquired by the sewing machine as it is the user wants to change only a specific character within the character string to a different character and then sew the embroidery pattern.
In that case, it may be necessary for the sewing machine to acquire the entire character string once again, even if the greater part of the character string is the same, and to create the embroidery data all over again. Therefore, it may be not always be possible to create the embroidery data and perform the sewing efficiently.
Various exemplary embodiments of the general principles herein provide a sewing machine that may comprise a processor; and a memory. The memory may be configured to store computer-readable instructions therein, wherein the computer-readable instructions instruct the sewing machine to execute steps comprising acquiring image data including one or more characters, extracting, from acquired image data, one or more character designs with respect to each character included in the acquired image data, wherein the character design represents each character included in the acquired image data, generating embroidery data with respect to each character based on the extracted character design, wherein the embroidery data represents an embroidery pattern in a predetermined size, selecting specific embroidery data, in response to accepting an instruction for specifying character design, from the generated embroidery data corresponding to the specified character design, and generating a signal based on the selected embroidery data, wherein the sewing machine is configured to sew an embroidery pattern represented by the selected embroidery data based on the signal.
Exemplary embodiments herein provide an apparatus that may comprise a processor and a memory. The memory may be configured to store computer-readable instructions therein, wherein the computer-readable instructions instruct the apparatus to execute steps comprising acquiring image data including one or more characters, extracting, from acquired image data, one or more character designs with respect to each character included in the acquired image data, wherein the character design represents each character included in the acquired image data, and generating embroidery data with respect to each character based on the extracted character design, wherein the embroidery data represents an embroidery pattern in a predetermined size.
Exemplary embodiments also provide a non-transitory computer readable medium. The non-transitory computer readable medium may store computer readable instructions that, when executed, instruct an apparatus to execute steps comprising acquiring image data including one or more characters, extracting, from acquired image data, one or more character designs with respect to each character included in the acquired image data, wherein the character design represents each character included in the acquired image data, and generating embroidery data with respect to each character based on the extracted character design, wherein the embroidery data represents an embroidery pattern in a predetermined size.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments of the present disclosure will be described below in detail with reference to the accompanying drawing in which:
FIG. 1 is an oblique view of a sewing machine 1 ;
FIG. 2 is a left side view that shows an area around a needle bar 6 , a sewing needle 7 , a presser bar 91 , and a presser foot 92 ;
FIG. 3 is a block diagram that shows an electrical configuration of the sewing machine 1 ;
FIG. 4 is a figure that shows an embroidery pattern 41 of a character “B”;
FIG. 5 is a flowchart of character acquisition processing;
FIG. 6 is a flowchart of the character acquisition processing, continued from FIG. 5 ;
FIG. 7 is a figure that shows an image 50 and characters 51 ;
FIG. 8 is a figure that shows a binary image 70 and character designs 53 ;
FIG. 9 is a figure that shows character designs 55 ;
FIG. 10 is a figure that shows character designs 56 ;
FIG. 11 is a figure that shows an embroidery pattern 44 of a character “B”;
FIG. 12 is a flowchart of sewing processing;
FIG. 13 is a figure that shows an embroidery pattern 58 that has been sewn;
FIG. 14 is a figure that shows character designs 57 ; and
FIG. 15 is a figure that shows an embroidery pattern 59 that has been sewn.
DETAILED DESCRIPTION
Hereinafter, an embodiment will be explained with reference to the drawings. A configuration of a sewing machine 1 will be explained with reference to FIGS. 1 and 2 . In the explanation that follows, the lower right, the upper left, the upper right, and the lower left in FIG. 1 respectively correspond to the front side, the rear side, the right side, and the left side of the sewing machine 1 . A direction in which a bed 11 (described later) extends corresponds to an X-axis direction. A direction that is perpendicular to the X-axis direction and that is parallel to the top face of the bed 11 corresponds to a Y-axis direction.
As shown in FIG. 1 , the sewing machine 1 includes a bed 11 , a pillar 12 , an arm 13 , and a head 14 . The bed 11 is a base portion of the sewing machine 1 that is longer in the left-right direction. The pillar 12 extends upward from the right end of the bed 11 . The arm 13 extends to the left from the upper end of the pillar 12 such that it is opposite the bed 11 . The head 14 is a portion that is connected to the left end of the arm 13 . A needle plate (not shown in the drawings) is provided in the top face of the bed 11 . A feed dog, a feed mechanism, and a shuttle mechanism (which are not shown in the drawings), and a feed adjustment pulse motor 78 (refer to FIG. 3 ) are provided underneath the needle plate (that is, within the bed 11 ). The feed dog may be driven by the feed mechanism and feed a work cloth by a specified feed amount. The feed amount may be adjusted by the feed adjustment pulse motor 78 .
An embroidery frame 34 that holds a work cloth 100 can be disposed on the top side of the bed 11 . The embroidery frame 34 may be a known structure that is configured to hold the work cloth 100 by clamping it with an inner frame and an outer frame. An embroidery frame moving device 33 has a known structure that is configured to move the embroidery frame 34 , so it will be explained briefly. The embroidery frame moving device 33 can be removably mounted on the bed 11 . A carriage 35 that extends in the front-rear direction is provided on top of the embroidery frame moving device 33 . A frame holder (not shown in the drawings) on which the embroidery frame 34 can be removably mounted and a Y axis moving mechanism (not shown in the drawings) that is configured to move the frame holder in the front-rear direction (the Y axis direction) are provided in the interior of the carriage 35 . The Y axis moving mechanism may be driven by a Y axis motor 84 (refer to FIG. 3 ).
An X axis moving mechanism (not shown in the drawings) that is configured to move the carriage 35 in the left-right direction (the X axis direction) is provided inside the embroidery frame moving device 33 . The X axis moving mechanism may be driven by an X axis motor 83 (refer to FIG. 3 ). As the carriage 35 is moved in the left-right direction (the X axis direction), the embroidery frame 34 is moved in the left-right direction (the X axis direction).
A needle bar 6 (refer to FIG. 2 ) and the shuttle mechanism (not shown in the drawings) may be driven in conjunction with the moving of the embroidery frame 34 in the left-right direction (the X axis direction) and the front-rear direction (the Y axis direction). This causes a sewing needle 7 (refer to FIG. 2 ) that is mounted in the needle bar 6 to sew an embroidery pattern in the work cloth 100 that is held by the embroidery frame 34 . When an ordinary pattern that is not an embroidery pattern is to be sewn, the embroidery frame moving device 33 is removed from the bed 11 . In that state, the sewing is performed as the work cloth is moved by the feed dog.
A vertically rectangular liquid crystal display (hereinafter called an LCD) 15 is provided in the front face of the pillar 12 . An image may be displayed on the LCD 15 based on image data that includes various types of items, such as commands, illustrations, setting values, messages, and the like. A touch panel 26 is provided on the front face of the LCD 15 . Using a finger or a special touch pen, a user may perform a pressing operation on the touch panel 26 . Hereinafter, this operation is called a panel operation. The touch panel 26 detects a position which is pressed by a finger or a special touch pen etc., and the sewing machine 1 determines the item that corresponds to the detected position. Thus, the sewing machine 1 recognizes the selected item. By performing the panel operation, the user can select a pattern to be sewn or a command to be executed.
The arm 13 is provided in its top portion with a cover 16 that can be opened and closed. Underneath the cover 16 , that is, approximately in the middle of the arm 13 , a thread container portion 18 is provided that is a recessed portion that may contain a thread spool 20 . A thread spool pin 19 that projects leftward toward the head 14 is provided on an inner side wall on the pillar 12 side of the thread container portion 18 . The thread spool 20 may be mounted in the thread container portion 18 in a state in which the thread spool pin 19 has been inserted into an insertion hole (not shown in the drawings) of the thread spool 20 .
An upper thread (not shown in the drawings) that is wound around the thread spool 20 may be supplied from the thread spool 20 , through a thread hook portions (not shown in the drawings) that are provided in the head 14 , to the sewing needle 7 that is mounted in the needle bar 6 (refer to FIG. 2 ). The needle bar 6 may be driven by a needle bar up-and-down moving mechanism (not shown in the drawings) that is provided in the head 14 , such that the needle bar 6 moves up and down. The needle bar up-and-down moving mechanism may be driven by a drive shaft (not shown in the drawings) that may be rotationally driven by a sewing machine motor 79 (refer to FIG. 3 ). A presser bar 91 extends downward from the bottom end of the head 14 . A presser foot 92 that presses down on the work cloth 100 may be replaceably mounted on the presser bar 91 . A plurality of operation switches, including a start-and-stop switch 32 , are provided in the lower part of the front face of the arm 13 .
An electrical configuration of the sewing machine 1 will be explained with reference to FIG. 3 . A control portion 60 of the sewing machine 1 includes a CPU 61 , a ROM 62 , a RAM 63 , an EEPROM 64 , an external access RAM 68 , a card slot 17 , an input interface 65 , and an output interface 66 . These elements are electrically connected to one another by a bus 67 . A plurality of operation switches, including a power supply switch 31 and the start-and-stop switch 32 , are electrically connected to the input interface 65 , as are the touch panel 26 and the like.
The ROM 62 stores various types of programs for controlling the operation of the sewing machine 1 . The CPU 61 may perform various types of computations and processing in accordance with the programs that are stored in the ROM 62 , temporarily storing various types of data in the RAM 63 . Standard character embroidery data are also stored in the ROM 62 . The standard character embroidery data are data for sewing characters in a standard style as embroidery patterns. The standard character embroidery data may represent an embroidery data of a standard design of a character. Data that indicate needle drop points, which are positions where the sewing needle 7 pierces the work cloth 100 , are also included in the standard character embroidery data. A sewing order, a sewing starting point, and a sewing ending point of an embroidery pattern are also included in the standard character embroidery data. The sewing order, the sewing starting point, and the sewing ending point will be described in detail later. Hereinafter, the sewing order, the sewing starting point, and the sewing ending point are also called setting information. The sewing machine 1 is able to sew characters in the standard style as embroidery patterns, based on the standard character embroidery data.
The setting information that is included in the standard character embroidery data will be explained with reference to FIG. 4 . FIG. 4 shows an embroidery pattern 41 of the alphabetic character “B”. The embroidery pattern 41 of the alphabetic character “B” in FIG. 4 is an example of an embroidery pattern that is sewn in the work cloth 100 (refer to FIG. 1 ) based on the standard character embroidery data. The embroidery pattern 41 is sewn by causing the sewing needle 7 to pierce the work cloth 100 at the needle drop points in the order that is indicated by arrows 42 , 43 . Information that indicates the sewing will be performed in the directions that are shown by the arrows 42 , 43 and in the order indicated by the arrows 42 , 43 is equivalent to the sewing order. Information that indicates a starting point 421 and an ending point 422 of the arrow 42 is equivalent to the sewing starting point and the sewing ending point, respectively. In the same manner, information that indicates a starting point 431 and an ending point 432 of the arrow 43 is also equivalent to the sewing starting point and the sewing ending point, respectively.
The setting information, that is, the sewing order, the sewing starting point, and the sewing ending point, have been adjusted such that an embroidered pattern with high quality can be sewn in the work cloth 100 based on the standard character embroidery data. Specific examples will be explained. Value of the setting information is adjusted such that jump stitches and basting occur as little as possible, or to put it another way, such that the character is sewn, to the extent possible, as if it were written as a single continuous line. Thus the high quality of the embroidered pattern may be ensured. This may prevent the occurrence of boundary lines and differences in the sewing direction within the embroidery pattern. The parameters in the setting information are also adjusted such that the sewing starts and stops on the underside of the standard character, to the extent possible. In a case where embroidery patterns of a character string in which a plurality of the standard characters are combined and sewn, this may prevent jump stitches from passing over the embroidered pattern between the embroidered patterns for the individual characters, thereby ensuring the high quality of the embroidered pattern. It may also minimize the amount of jump stitch removal work the user must do.
As shown in FIG. 3 , a memory card 171 can be inserted into the card slot 17 . The CPU 61 is able to acquire, through the external access RAM 68 , information that is stored in the memory card 171 . In the present embodiment, the user may store in the memory card 171 image data which represents an image that contains at least one character in a desired style, in order for the at least one character in the desired style to be sewn as an embroidery pattern by the sewing machine 1 . The at least one character in the desired style may be a character that is handwritten by the user, a character that is prepared in a font of the user's own devising, or the like. The CPU 61 may acquire the image data that is stored in the memory card 171 . Then the CPU 61 may create embroidery data for sewing, as an embroidery pattern, each of the characters that are contained in the image represented by the image data. The embroidery data may be created based on the setting information that is included in the standard character embroidery data that are stored in the ROM 62 . The method for creating the embroidery data will be described in detail later. The created embroidery data may be stored in the EEPROM 64 .
Drive circuits 71 to 74 , 85 , and 86 are electrically connected to the output interface 66 . The drive circuit 71 may drive a feed adjustment pulse motor 78 . The drive circuit 72 may drive a sewing machine motor 79 . The drive circuit 73 may drive a swinging pulse motor 80 . The swinging pulse motor 80 may drive a needle bar swinging mechanism (not shown in the drawings) that swings the needle bar 6 . The feed adjustment pulse motor 78 and the swinging pulse motor 80 are not driven during the sewing of the embroidery pattern. The drive circuit 74 may drive the LCD 15 . The drive circuits 85 and 86 may respectively drive the X axis motor 83 and the Y axis motor 84 for moving the embroidery frame 34 .
Character acquisition processing and sewing processing that are performed by the sewing machine 1 will be explained with reference to FIGS. 5 to 15 . The character acquisition processing is processing that creates an embroidery data based on image data of at least one character that is stored in the memory card 171 . The sewing processing is processing that performs the sewing of an embroidery pattern based on the created embroidery data. Hereinafter, each type of processing will be explained in detail.
The character acquisition processing will be explained with reference to FIGS. 5 and 6 . The character acquisition processing is started by the launching of a character acquisition processing program that is stored in the ROM 62 , the program being launched in a case where the memory card 171 has been inserted into the card slot 17 . The character acquisition processing in FIGS. 5 and 6 is performed by the executing of the program by the CPU 61 . As shown in FIG. 5 , first, the image data that is stored in the memory card 171 is acquired (Step S 11 ). The acquired image data is stored in the RAM 63 . In the explanation that follows, which references FIGS. 7 to 10 , an example will be used in which image data of an image 50 shown in FIG. 7 is acquired and stored in the RAM 63 . The image 50 contains ten characters 51 (a character 51 A, a character 51 B, a character 51 C, a character 51 D, a character 51 E, a character 51 F, a character 51 G, a character 51 H, a character 51 I, and a character 51 J) that were handwritten by the user. Note that the characters 51 include an Arabic numeral, plus Japanese hiragana and kanji character.
As shown in FIG. 5 , the image data of the image 50 (refer to FIG. 7 ) that is stored in the RAM 63 is converted into binary image data of a binary image 70 (refer to FIG. 8 ) in order for the characters 51 (refer to FIG. 7 ) that are contained in the image 50 to be recognized (Step S 13 ). Various types of known methods can be used as the method for converting the image data of the image 50 into the binary image data of the image 70 . For example, a method that binarizes according to a threshold value can be used. Other examples of methods that can be used include a random dither method and an error diffusion method. Converting the image data of the image 50 into the binary image data of the image 70 makes the differences in the gray levels clearer between the areas where the characters 51 are and the areas outside the characters 51 , so it makes the characters 51 that are contained in the image 50 easier to recognize.
The characters 51 that are contained in the binary image 70 (refer to FIG. 8 ) are recognized by using a known character recognition method. The regions in which the characters 51 are respectively drawn in the binary image 70 are specified for each individual character 51 (Step S 15 ). Pattern matching by a superposition technique, for example, can be used as the known character recognition method. A rectangle 52 (refer to FIG. 8 ) is defined that is the smallest rectangle that encloses on all sides the region in which the individual character 51 is drawn. One of the regions in which one of the characters 51 is drawn is extracted from the binary image 70 according to the outline of the defined rectangle 52 , and image data of the extracted region is stored in the RAM 63 (Step S 17 ). Hereinafter, the design that indicates the image data of the extracted individual character will also be called a character design 53 (refer to FIG. 8 ). Note that because the rectangle 52 is the smallest rectangle that encloses on all sides the region in which the individual character 51 is drawn, cases may occur in which the vertical length and the horizontal length of the individual character design 53 are different, as shown in FIG. 8 . As shown in FIG. 5 , a determination is made as to whether the extracting of the character design 53 and storing the image data of the extracted character design 53 in the RAM 63 have been carried out for all of the characters 51 that are contained in the binary image 70 (Step S 19 ). In a case where a characters 51 remains for which the extracting of the character design 53 and its storing in the RAM 63 have not been carried out (NO at Step S 19 ), the processing returns to Step S 17 . The processing at Step S 17 is repeated for the remaining character 51 .
In a case where the extracting and storing have been completed for all of the characters 51 that are contained in the binary image 70 (YES at Step S 19 ), the image data of the first one of the plurality of character designs 53 that have been stored in the RAM 63 is selected, as shown in FIG. 6 . A character design 55 (refer to FIG. 9 ) is produced by making the lengths of the short sides of the rectangular character design 53 equal to the lengths of the long sides of the character design 53 (Step S 21 ). In other words the character design 55 is produced by redefining the character design 53 in accordance with a square 54 (refer to FIG. 9 ), each of whose sides is equal to the long side of the rectangle 52 that was defined by the processing at Step S 17 . The short sides of the rectangular character design 53 are lengthened equally, either toward the top and bottom or toward the left and right, so the character 51 that is contained in the character design 55 is positioned in the center of the square 54 . The shape of the character 51 that is contained in the character design 53 and the character design 55 is not changed.
The size of the character design 55 is adjusted. Specifically, in a case where the length of one side of the square 54 that contains the character design 55 is not a specified value, the character design 55 is one of enlarged and shrunk such that the length of one side of the square 54 becomes the specified value (Step S 23 ). The character design 55 whose size has been adjusted is then redefined as a character design 56 (refer to FIG. 10 ). Because the size of the character design 55 is one of enlarged and shrunk, the size of the character 51 that is contained in the character design 55 is also changed accordingly. Thus the character design 56 thus produced has the same size as the other character designs 56 that are respectively produced from all the other character designs 55 . Note that in a case where the length of one side of the square 54 that contains the character design 55 is the specified value, the size of the character design 55 is not changed, and the unchanged character design 55 is redefined as the character design 56 .
The character 51 that is contained in the character design 56 is recognized by a known character recognition method, and the type of the character 51 is specified (Step S 25 ). Pattern matching by feature extraction, for example, can be used as the known character recognition method. The specified character is compared to a standard character that is sewn according to the standard character embroidery data that are stored in the ROM 62 (Step S 27 ). A determination is made as to whether the standard character embroidery data for a character that is the same as the specified character are stored in the ROM 62 (Step S 29 ). In the present example, a determination is made as to whether the standard character embroidery data are stored in the ROM 62 for a character that is the same as whichever one of the character 51 A, the character 51 B, the character 51 C, the character 51 D, the character 51 E, the character 51 F, the character 51 G, the character 51 H, the character 51 I, and the character 51 J (refer to FIG. 7 ) is currently being processed.
In a case where the standard character embroidery data for the same character that is the same as the specified character are not stored in the ROM 62 (NO at Step S 29 ), the image data of the character design 56 is converted using a known conversion technology, and the embroidery data for sewing the character design 56 as an embroidery pattern are created (Step S 33 ). The embroidery data for the character design 56 are stored in the EEPROM 64 (Step S 35 ). The processing advances to Step S 37 .
The embroidery pattern that is sewn based on the embroidery data that have been created using the known conversion technology will be explained. With the known conversion technology, a character is ordinarily divided into block units. The setting information (the sewing order, the sewing starting point, and the sewing ending point) that is included in the embroidery data is set such that the sewing will be performed with adjacent blocks being taken into account. The blocks are sections into which the character is divided by curving portions. That means that even where it is possible to sew the character as if it were written as a single continuous line, in many cases the character is actually sewn in part. Therefore, cases may occur in which the quality of the embroidered pattern is affected by differences in the sewing direction and boundary lines that are formed within the character. Furthermore, with the known conversion technology, the sewing starting point and the sewing ending point are set such that the sewing is started at the upper left of the character, and the sewing ends at any chosen point in the character. Therefore, a case may occur in which a jump stitch passes over the embroidered character.
FIG. 11 shows an embroidery pattern 44 of the alphabetic character “B” as an example of an embroidery pattern that is sewn based on the embroidery data that have been created using the known conversion technology. The embroidery pattern 44 is sewn by causing the sewing needle 7 to pierce the work cloth 100 at the needle drop points in the order that is indicated by arrows 45 , 46 , which is based on the sewing order that is contained in the embroidery data. Values are set that indicate positions of a starting point 451 of the arrow 45 and a starting point 461 of the arrow 46 as the sewing starting points. In the same manner, values are set that indicate positions of an ending point 452 of the arrow 45 and an ending point 462 of the arrow 46 as the sewing ending points. Unlike the embroidery pattern 41 of the alphabetic character “B” (refer to FIG. 4 ), which is sewn based on the standard character embroidery data, the embroidery pattern 44 is divided at the position where the ending point 452 of the arrow 45 and the ending point 462 of the arrow 46 meet. A boundary line is therefore formed at that position. Furthermore, because the ending point 462 of the arrow 46 is positioned higher than the bottom edge of the character, in a case where embroidery patterns are sewn in which a plurality of characters are combined with the alphabetic character “B” to form a character string, a jump stitch between the embroidered patterns for the individual characters may pass over the embroidered pattern.
On the other hand, as shown in FIG. 6 , in a case where the standard character embroidery data for the same character as that of the character that was specified are stored in the ROM 62 at Step S 25 (YES at Step S 29 ), the embroidery data for sewing the character design 56 as an embroidery pattern are created based on the setting information that is included in the standard character embroidery data (Step S 31 ). Specifically, the setting information that is included in the embroidery data that are created is almost equal to the setting information that is included in the standard character embroidery data. Therefore, in a case where the sewing is performed based on the created embroidery data, the sewing order, the sewing starting point, and the sewing ending point respectively match the sewing order, the sewing starting point, and the sewing ending point that are included in the standard character embroidery data. As was explained with reference to FIG. 4 , the setting information (the sewing order, the sewing starting point, and the sewing ending point) that is included in the standard character embroidery data have been adjusted such that the high quality embroidered pattern can be sewn in the work cloth 100 based on the standard character embroidery data. Therefore, in a case where the embroidery data is created based on the setting information that is included in the standard character embroidery data, the embroidery data make it possible for the character design 56 to be sewn as an embroidered pattern with high quality. The embroidery data that are created for the individual character are stored in the EEPROM 64 (Step S 35 ). The processing advances to Step S 37 .
At Step S 37 , a determination is made as to whether the processing at Steps S 21 to S 35 has been performed for all image data of character designs 53 that were stored in the RAM 63 at Step S 17 (refer to FIG. 5 ) (Step S 37 ). In a case where image data of a character design 53 remains in the RAM 63 for which the processing has not been performed (NO at Step S 37 ), the processing returns to Step S 21 . In a case where the processing has been performed for all image data of character designs 53 were stored in the RAM 63 (YES at Step S 37 ), the embroidery data for sewing as embroidery patterns all of the characters 51 that are contained in the image 50 have been created character by character. The character acquisition processing is terminated.
The sewing processing will be explained with reference to FIG. 12 . An explanation will be given below, using a case in which the user first creates a character string in which the character designs 56 (refer to FIG. 10 ) that were acquired by the sewing machine 1 in the character acquisition processing (refer to FIGS. 5 and 6 ), are arranged in a desired order, and then sew the character string in the work cloth 100 as an embroidery pattern. The sewing processing is started by the launching of a sewing processing program that is stored in the ROM 62 , the program being launched in a case where a command to perform sewing of an embroidery pattern is input by the user through the touch panel 26 (refer to FIG. 1 ). The sewing processing is performed by the executing of the program by the CPU 61 .
First, in a case where the user's desired character string is input through the touch panel 26 , the input character string is accepted (Step S 41 ). The characters that are included in the accepted character string are specified. The embroidery data for sewing the specified characters as embroidery patterns are selected from among the embroidery data that were stored in the EEPROM 64 at Step S 35 in the character acquisition processing (refer to FIG. 6 ) (Step S 43 ). For example, the user inputs a character string in which the ten characters 51 (the character 51 A, the character 51 B, the character 51 C, the character 51 D, the character 51 E, the character 51 F, the character 51 G, the character 51 H, the character 51 I, and the character 51 J) that are contained in the image 50 (refer to FIG. 7 ) are arranged in the same order as in the image 50 . In this case, the embroidery data for sewing, as embroidery patterns, each of the characters 51 A to 51 J that are included in the input character string, respectively, are selected from the EEPROM 64 .
Next, in a case where the user performs, through the touch panel 26 , an operation that edits the character string, the content of the editing is accepted (Step S 45 ). The content of the editing may include alignment of the characters, adjustment of the embroidery position, rotation, and the like, for example. In accordance with the accepted editing content, edit processing is performed on the embroidery data that were selected at Step S 43 (Step S 45 ). The sewing of the embroidery patterns is performed by controlling the various types of motors based on the edited embroidery data (Step S 47 ). The result, as shown in FIG. 13 , is that an embroidery pattern 58 is sewn in the work cloth 100 , the embroidery pattern 58 including the character designs 56 (refer to FIG. 10 ) that were acquired by the character acquisition processing (refer to FIG. 5 ) and that include the characters 51 A to 51 J. The sewing processing is then terminated.
Now, another case will be given in which in addition to the image data of the image 50 (refer to FIG. 7 ), image data of an image that is different from the image 50 has been acquired from the memory card 171 (refer to FIG. 3 ) in the character acquisition processing (refer to FIGS. 5 and 6 ). In this case, based on the acquired image data, embroidery data has been created for sewing, as embroidery patterns, character designs 57 that are shown in FIG. 14 , and that the created embroidery data has been stored in the EEPROM 64 . Thus, the embroidery data for sewing, as embroidery patterns, the character designs 56 , which include the characters 51 A to 51 J (refer to FIG. 10 ), and the character designs 57 , which include a character 51 K, a character 51 L, a character 51 M, a character 51 N, a character 51 O, and a character 51 P (refer to FIG. 14 ), have been stored in the EEPROM 64 character by character.
For example, the character 51 K, the character 51 B, the character 51 L, the character 51 M, the character 51 N, the character 51 O, the character 51 F, the character 51 G, the character 51 H, the character 51 I, and the character 51 P (refer to FIGS. 10 and 14 ) are accepted at Step S 41 as the character string that the user desires. Of the characters 51 A to 51 J in the character designs 56 (refer to FIG. 10 ) that were created based on the image data of the image 50 , in this character string, the character 51 A is replaced by the character 51 K, while the character 51 C, the character 51 D, and the character 51 E are replaced by the character 51 L, the character 51 M, the character 51 N, and the character 51 O, and the character 51 J is replaced by the character 51 P. In this sort of case, the embroidery data that correspond to the individual characters that are included in the accepted character string are selected, character by character, from the embroidery data that are stored in the EEPROM 64 (Step S 43 ), and after the edit processing (Step S 45 ), the sewing of the embroidery pattern is performed (Step S 47 ). The result, as shown in FIG. 15 , is that an embroidery pattern 59 is sewn in the work cloth 100 , the embroidery pattern 59 including the character designs 56 , 57 that were acquired by the character acquisition processing and that include the character 51 K, the character 51 B, the character 51 L, the character 51 M, the character 51 N, the character 51 O, the character 51 F, the character 51 G, the character 51 H, the character 51 I, and the character 51 P.
As explained above, the sewing machine 1 is able to extract, character by character, the characters 51 that are contained in the acquired image 50 without changing the style of the characters 51 (Step S 17 ), and is able to sew the embroidery patterns for the character designs 56 of the extracted characters 51 (Step S 47 ). Therefore, the user is able to sew an embroidery pattern of a character that is not registered in the sewing machine 1 in advance, such as a character that is handwritten by the user or a character that is prepared in a special font, for example. Because the embroidery data are created character by character (Step S 17 ), the sewing machine 1 is also able to easily sew an embroidery pattern in which a plurality of character designs 56 are combined as the user desires (Steps S 41 to S 47 ). Even in a case where the sizes of the characters that are contained in the image 50 are not uniform, the sewing machine 1 creates the character designs 56 such that the character sizes are the same (Step S 23 ) and creates the embroidery data (Step S 31 ) that make it possible to sew the embroidery pattern. Therefore, in a case where the embroidery pattern that is sewn is of a character string in which a plurality of characters are positioned side by side, the characters can be sewn in a uniform size, so an attractive embroidery pattern that shows unity as a whole can be sewn. Note that the embroidery data are created after the character designs 56 have been adjusted by making the sizes of the character designs 55 uniform. Therefore, the sizes of the embroidery patterns to be sewn can be reliably made uniform.
The sewing machine 1 is also able to create the embroidery data based on the standard character embroidery data (Step S 31 ), so it is able to sew the embroidery pattern with a good finish. Specifically, the sewing machine 1 is able to make the setting information (the sewing order, the sewing starting point, and the sewing ending point) for the embroidery pattern of the character designs 56 resemble the setting information of the standard character embroidery data. This makes it possible for the sewing machine 1 to sew the embroidery pattern with an even better finish.
The sewing machine 1 can also create embroidery data of a character string by selecting from the EEPROM 64 (Step S 43 ) the embroidery data for the embroidery patterns of the character designs 56 that were created character by character in accordance with a character string that was input. Therefore, by using the sewing machine 1 , the user can freely create a character string that includes characters in a desired style and can perform the embroidering of the embroidery patterns for that character string.
Note that the present disclosure is not limited to the embodiment that is described above, and various types of modifications can be made. The sewing machine 1 may also always use a known conversion method to create the embroidery data for sewing the character designs 56 as embroidery patterns, without referring to the standard character embroidery data that are stored in the ROM 62 . The setting information that is included in the standard character embroidery data is not limited to being the sewing order, the sewing starting point, and the sewing ending point. Instead of creating the embroidery data after the sizes of the character designs 56 have been modified, the sewing machine 1 may first create the embroidery data based on the unmodified character designs 56 , then change the embroidery data such that the sizes of the embroidery patterns to be sewn according to the embroidery data are changed. The sewing machine 1 may also acquire the standard character embroidery data from a server or the like to which the sewing machine 1 is connected through a network.
The present disclosure may also be implemented in an embroidery data creation device that creates the embroidery data. The embroidery data creation device may be configured as a general-purpose computer, for example. In the embroidery data creation device, the embroidery data may be created by the performing of the character acquisition processing (refer to FIGS. 5 and 6 ). The created embroidery data may be acquired by the sewing machine 1 through the memory card 171 or the like. The sewing machine 1 may perform the sewing of the embroidery pattern based on the acquired embroidery data.
In the embodiment that is described above, the image data of the image 50 that is stored in the memory card 171 is acquired, and the character designs 56 are extracted. The image data of the image 50 may also be acquired by another method. For example, in a case where the sewing machine 1 is connected to a camera or a scanner, the sewing machine 1 may acquire the image data from the camera or the scanner. In a case where the embroidery data are created in the sewing machine 1 based on a plurality of character designs in which the characters are the same, the sewing machine 1 may also be made such that the user can select the embroidery data that are based on the desired character designs.
The setting information in the standard character embroidery data may also be made such that the user can adjust it. For example, the sewing machine 1 may be made such that the user can set the setting information in the embroidery data manually in a case where the standard character embroidery data for characters that are the same as the characters in the created character designs have not been stored in the ROM 62 . The sewing machine 1 may also create the embroidery data for sewing the character designs as the embroidery patterns based on the setting information that has been set.
In a case where the standard character embroidery data for characters that are the same as the characters in the created character designs have not been stored in the ROM 62 , the sewing machine 1 may also create the embroidery data for sewing the character designs as the embroidery patterns based on the setting information that is included in the standard character embroidery data for other characters whose shapes resemble those of the characters in the character designs.
The apparatus and methods described above with reference to the various embodiments are merely examples. It goes without saying that they are not confined to the depicted embodiments. While various features have been described in conjunction with the examples outlined above, various alternatives, modifications, variations, and/or improvements of those features and/or examples may be possible. Accordingly, the examples, as set forth above, are intended to be illustrative. Various changes may be made without departing from the broad spirit and scope of the underlying principles.
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An apparatus includes a processor and a memory. The memory is configured to store computer-readable instructions therein, wherein the computer-readable instructions instruct the sewing machine to execute steps comprising acquiring image data including one or more characters, extracting, from acquired image data, one or more character designs with respect to each character included in the acquired image data, wherein the character design represents each character included in the acquired image data, generating embroidery data with respect to each character based on the extracted character design, wherein the embroidery data represents an embroidery pattern in a predetermined size.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a division of U.S. patent application Ser. No. 08/598,926, filed Feb. 9, 1996, now U.S. Pat. No. 5,670,545, which is incorporated in its entirety by reference herein
FIELD OF THE INVENTION
The present invention relates to a method for the treatment of ischemic diseases using N-mercaptoalkanoylcysteine compounds. These compounds also protect tissue from the adverse effects of reactive oxygen species.
BACKGROUND OF THE INVENTION
In acute myocardial infarction, cardiac tissue is damaged by two sequential events, hypoxia in the ischemic phase and oxidative damage in the reperfusion phase. Damaged cardiac tissue in the ischemic phase can be salvaged by restoring blood flow to the ischemic region through reperfusion. However, restoration of blood containing oxygen can result in injury due to the production of reactive oxygen species Biochim. Biophys. Acta, 890:82-88 (1987)!. Two of these reactive oxygen species, hydrogen peroxide and superoxide radical, are thought to be of particular importance in causing injury to myocardial cells exposed to ischemia and reperfusion Free Radical Res. Commun. 9:223-232 (1990); Basic Res. Cardiol. 84:191-196 (1989)!. Injury from hydrogen peroxide and superoxide radicals occurs when in the presence of iron there is generation of highly toxic hydroxyl radicals Am. J. Physiol. (1994) 266:H121-H127!. Hydroxyl radicals can also be produced from the simultaneous generation of superoxide radical and nitric oxide, and this reaction could also cause tissue injury ( Biochemical J. 281:419-424 (1992)!. If hydrogen peroxide, superoxide radical, or other reactive oxygen species accumulate during the reperfusion phase, various toxic reactions can occur which result in myocardial cell injury or death. Similar injury to heart tissue can occur during heart surgery when bypass procedures or other manipulations result in an ischemic phase followed by a reperfusion phase. Similar injury to other organs such as the brain, kidney or intestine can also occur due to ischemia and reperfusion and production of reactive oxygen species J. Appl. Physiol. 71:1185-1195 (1991); Kidney Int. 40:1041-1049 (1991)!. Injury due to generation of reactive oxygen species, probably resulting from exposure to ischemia and reperfusion, also occurs during transplantation of organs such as hearts, kidneys, livers or lungs J. Thorax. Cardiovasc. Surgery (1992) 103:945-951; Clinical Transplantation (1995) 9:171-175!. In addition, injury due to reactive oxygen species to the coronary arteries or other blood vessels can occur either due to exposure to ischemia and reperfusion Am. J. Physiol. 260:H42-H49 (1990)! or under other conditions when they may contribute to atherosclerosis Proc. Natl. Acad. Sci. U.S.A. 84:2995-2998 (1987)!. Although ischemia followed by reperfusion is the usual cause of production of reactive oxygen species in the myocardium and blood vessels, there may be accumulation of reactive oxygen species in these organs from other mechanisms. For example, the accumulation of reactive oxygen species has been implicated in heart failure Free Radical Biology Med. 14:643-647 (1993)!. Production of superoxide radical or other reactive oxygen species in vascular tissue can cause tolerance to certain drugs used for treatment of heart disease, such as nitroglycerin and related nitrates J. Clin. Invest. 95:187-194 (1995)!.
There is a need for methods of treatment of ischemia and reperfusion which avoid the problems in prior art methods. More specifically, there is a need for improved methods of reperfusion in which the effects of reactive oxygen species are neutralized. This invention provides N-mercaptoalkanoylcysteine compounds that ameliorate or prevent the toxic effects of reactive oxygen species, including but not limited to hydrogen peroxide and superoxide radical, without themselves damaging tissue.
N-mercaptoalkanoylcysteine derivatives have been reported to be useful for a variety of pharmaceutical applications, for example for the treatment of hepatic diseases and autoimmune diseases such as rheumatoid arthritis (see Laid-Open Japanese Patent Application No. 2-776).
The N-mercaptoalkanoylcysteine, bucillamine (N-(2-methyl-2-mercaptopropionyl)-L-cysteine, also designated 2-mercaptoisobutyroyl-1-cysteine) (See: U.S. Pat. No. 4,305,958) which has formula: ##STR1## is reported useful in a variety of pharmaceutical applications: as a dissolving agent for sputum (see Laid-Open Japanese Patent Application No. 53-5112), an anti-rheumatic agent (see Laid-Open Japanese Patent Application No. 55-51020), a treatment for cataracts (see Laid-Open Japanese Patent Application No. 55-92315, a treatment for diabetes (see Laid-Open Japanese Patent Application No. 4-154721), and a treatment for osteoporosis (see Laid-Open Japanese Patent Application No. 4-154722). Its homolog N-2,2-dimethyl-3-mercaptopropionyl)-L-cysteine (See: U.S. Pat. No. 5,292,926), hereafter Compound A, of formula: ##STR2## is reported useful for treatment of cataracts (see Laid-Open Japanese Patent Application No. 6-56661). None of these reports of therapeutic applications of bucillamine, Compound A or other N-mercaptoalkanoylcysteines teaches or suggests the use of these compounds to prevent or treat reperfusion injury.
2-Mercaptopropionylglycine (MPG) of formula: ##STR3## and related compounds, including bucillamine (but not Compound A) were tested for their ability to treat mitochondrial dysfunction and postischemic myocardial damage (Arzneim-Forschung Drug Research (1985) 35:1394-1402). This reference suggests that a compound that has the ability to protect mitochondrial function (as assessed by several in vitro tests) will have some ability to protect cells from damage from ischemia and reperfusion. The results reported are that all thiols tested, at least partially, recouple FCCP-uncoupled mitochondria and that most thiols tested including MPG and bucillamine, protect mitochondrial function from aging. However, in the apparently key experiment to assess utility of the test compounds for improvement of damaged heart function, the assessment of increased aortic flow in a working rat heart preparation, MPG and its oxidized dimer were found to significantly enhance aortic flow, while bucillamine and a number of other thiols display negligible effect. This reference suggests that MPG, not thiols in general and not bucillamine, will have a therapeutic utility for treatment of reperfusion damage.
Contrary to the reports of the prior art, this invention demonstrates that bucillamine, its homolog Compound A and structurally related N-mercaptoalkanoylcysteines, are highly effective for protecting cultured cardiac myoctes against oxidant injury and are, in fact, about twice as effective in this assay compared to MPG.
SUMMARY OF THE INVENTION
This invention provides a method for treatment of ischemic diseases such as myocardial infarction, cerebral infarction, and related diseases such as heart failure and atherosclerosis and other conditions involving injury to mammalian tissue by reactive oxygen species. The methods of treatment of this invention involve the administration of a pharmaceutically effective amount of a N-mercaptoalkanoylcysteine derivatives of formula I: ##STR4## or a pharmaceutically acceptable salt thereof together with a pharmaceutically acceptable carrier to a mammal exhibiting symptoms of the disease or disorder. In formula I, R 1 and R 2 , independently of one another, can be alkyl groups, particularly lower alkyl groups; R 3 can be a carboxyl group or an ester or amide thereof; R 4 or R 5 , independently of one another, are selected from the group consisting of a hydrogen atom, an alkyl group, an alkanoyl group, a phenyl-alkyl group or a phenylcarbonyl group, and the phenyl ring in the phenyl-alkyl and phenylcarbonyl groups can be substituted by at least one selected from halogen atoms, and alkyl, hydroxy, alkoxy, alkylenedioxy, nitro, amino and alkylamino groups; n is an integer that is 0 or 1; and "A" is a lower alkylene group, such as a --CH 2 -- group. For all R groups of formula I that contain alkyl, alkenyl, phenyl-alkyl, alkanoyl, alkoxy, alkylenedioxy or alkylamino groups, preferred groups are those that contain from 1 to about 6 carbon atoms (i.e., lower alkyl).
Preferred N-mercaptoalkanoylcysteine derivatives are those which exhibit an enhanced pharmaceutical effect, substantially greater than that exhibited by MPG, for prevention of cell injury due to reactive oxygen species which are produced during reperfusion of ischemic organs. Preferred N-mercapto-alkanoylcysteine derivatives are those in which R 1 and R 2 are lower alkyl (having from 1 to about 6 carbon atoms); those in which R 4 and R 5 are hydrogen or methyl groups; those in which A is --CH 2 --. More preferred N-mercaptoalkanoylcysteine derivatives useful for treatment of ischemic diseases are bucillamine and Compound A.
The invention is also directed to a method of protecting live mammalian tissue from injury resulting from exposure to reactive oxygen species formed after reestablishment of blood flow to a body organ after restriction of blood flow to that organ. It comprises administration of a compound of formula I or a pharmaceutically acceptable salt thereof along with pharmaceutically acceptable carriers. Preferred compounds of formula I in this method are bucillamine and Compound A.
This invention is further directed to the use of compounds of this invention of formula I for the preservation of mammalian organs, organ tissue or other tissue during transplantation procedures. An amount of the compound effective for preservation of the organ or tissue is included in the preservation solution in which the organ or tissue is contacted during transplantation.
The pH in water of certain of the compounds of this invention is acidic so that it may be necessary to neutralize aqueous solutions with a base such as NaOH to preferably achieve physiologic pH.
The compounds of this invention can be easily administered either orally or parenterally as appropriate for treatment of a given ischemic disorder. They can be readily administered, for example, at the time of reperfusion to rapidly neutralize the damaging effects of reactive oxygen species.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph of Cell Injury Index as a function of time for exposure to 100 μM H 2 O 2 and various concentrations of BUC bucillamine (and one concentration of MPG). Cell injury index reflects release of lactate dehydrogenase (LDH) from injured cells. Results shown are for H 2 O 2 alone (solid line, open triangles); 250 μM MPG+H 2 O 2 (dashed line, solid squares); 125 μM Buc+H 2 O 2 (solid line, open squares); 250 μM Buc+H 2 O 2 (solid line, closed circles); 500 μM Buc+H 2 O 2 (solid line, open circles). These results were obtained when cultured adult rat cardiac myocytes were exposed to H 2 O 2 for 4 hours with or without simultaneous treatment with bucillamine or MPG. Both MPG and bucillamine reduced Cell Injury Index, but bucillamine was approximately twice as effective on an equimolar basis compared with MPG.
FIG. 2 is a graph of Cell Injury Index as a function of time for exposure to 100 μM H 2 O 2 with various concentrations of compound A (CpdA) or MPG. Cell Injury Index reflects release of LDH from injured cells. Results shown are for H 2 O 2 alone (solid line, open triangles); 250 μM MPG+H 2 O 2 (dashed line, solid squares); 125 μM CpdA+H 2 O 2 (solid line, open squares); 250 μM CpdA +H 2 O 2 (solid line, closed circles); 500 μM CpdA+H 2 O 2 (solid line, open circles). Cultured adult rat cardiac myocytes were exposed to H 2 O 2 for 4 hours with or without treatment with CpdA or MPG. Both MPG and CpdA reduce Cell Injury Index, but CpdA was approximately twice as effective on an equimolar basis compared with MPG.
DETAILED DESCRIPTION OF THE INVENTION
Definitions
The following terms used herein are defined:
The term "alkyl group" takes its standard meaning to indicate a linear or branched alkyl group. The term lower alkyl group indicates alkyl groups having from 1 to about 6 carbon atoms and includes for example methyl, ethyl, propyl, pentyl, hexyl, isopropyl, isobutyl, isopentyl, isohexyl, t-butyl and t-pentyl groups. More preferred lower alkyl groups are methyl and ethyl groups.
The term "alkoxy group" takes its standard meaning to indicate a linear or branched alkoxy group. The term lower alkoxy indicates alkoxy groups having from 1 to about 6 carbon atoms and includes for example methoxy, ethoxy, propoxy, pentoxy, hexlyoxy, isopropoxy, isobutoxy, isopentoxy, isohexyloxy, t-butoxy and t-pentoxy. groups. More preferred lower alkoxy groups are methoxy and ethoxy groups.
The terms "alkanoyl", "alkylene", and "alkylenedioxy" take their standard meaning in the art. When these terms are modified by the word "lower" they refer to linear or branched groups having from 1 or 2 (as appropriate for the particular group) up to about 6 carbon atoms. Alkylenedioxy groups have a linear or branched alkylene group between two oxygen atoms. Exemplary alkanoyl groups include: acetyl, propionyl, butyryl, valeryl, pivaloyl, among others. The more preferred alkanoyl group is acetyl. Exemplary alkenyl groups include, methylene, ethylene, trimethylene, hexamethylene, propylene, (ethyl)methylene, and (dimethyl)methylene groups. Exemplary alkylenedioxy groups include: methylenedioxy, ethylenedioxy, propylenedioxy, and (diethyl)methylenedioxy.
The term "phenyl-alkyl" refers to a group containing a phenyl and a linear or branched alkyl group. The group may be attached to the core via the alkyl group, such as in a benzyl group or the phenyl group, such as in a (4-methyl)phenyl group. The phenyl ring in the phenyl alkyl group can be substituted by at least one group selected from the group of halogen atoms (F, Cl, or I) lower alkyl, hydroxy, lower alkoxy, lower alkylenedioxy, nitro, amino, and lower alkylamino.
The terms "ester" or "amide" refer to ordinary esters or amides of carboxylic acids. Lower alkyl esters include methyl esters, ethyl esters, isopropyl esters, butyl esters and hexyl esters. Esters include phenyl-alkyl esters, such as benzyl esters. Amides include amides with ammonia; lower alkyl amines either primary or secondary amines, such as methyl amine, diethyl amine, ethyl amine, diethyl amine; and amides with phenyl-alkylamines, such as benzylamine. Preferred esters are methyl, ethyl or benzyl esters. Preferred amides are amides with ammonia or amides with methyl amine, dimethyl amine, ethyl amine or diethyl amine.
Pharmaceutically acceptable salts of the compounds of this invention are those acceptable for use in medicines administered to mammals or humans. They include, among many others, salts with alkali metals or alkaline earth metals; ammonium salts; and salts with organic amines such as diethylamine or triethanolamine.
The compounds of this invention include diastereomers and optical isomers of the compound whose formulas are specifically provided. The invention also includes the compounds specifically described in the form of their hydrates.
The clinical utility of the administration of the N-mercaptoalkanoylcysteine derivatives described above was demonstrated by application to adult rat cardiac myocytes. A method has been reported for determining the degree of cell damage in cardiac muscle due to exposure to reactive oxygen species by measuring the amount of lactate dehydrogenase released from cultured myocardial cells see Am. J. Physiol., 266:H121-H127 (1994)!. The amount of lactate dehydrogenase released is quantitated by measurement of the activity of this enzyme in the medium in wells in which cultured myocardial cells are grown. In this manner damage can be assessed by either the addition of hydrogen peroxide to wells containing cultured myocardial cells or by adding a mixture of xanthine and xanthine oxidase which is employed for production of hydrogen peroxide and superoxide radical in the wells. Using this method in cultured myocardial cells the compounds of the invention are tested to determine whether they prevent or reduce the cell-damaging effects of exposure to hydrogen peroxide alone or of exposure to xanthine and xanthine oxidase, for production of hydrogen peroxide and superoxide radical.
Method for Assessing Test Compounds for Utility in the Treatment of Ischemic Disorders and Protection form Reactive Oxygen Species
The thorax of a male rat was cut open. Calcium free, modified Krebs Ringer buffer solution that had been cooled with ice in water was introduced into the thoracic cavity, and the heart together with a contiguous portion of the aorta was excised. The aorta was then cannulated for perfusion of the heart by the noncirculating Langendorf technique using collagenase and hyaluronidase in a modified Krebs Ringer buffer solution containing 50 μM Ca 2+ , which was at 37° C. and gassed with oxygen and 5% carbon dioxide. The ventricles were then separated and cut into small pieces which were incubated in collagenase and trypsin in a modified Krebs Ringer buffer solution containing 50 μM Ca 2+ , which was at 37° C. and gassed with oxygen and 5% carbon dioxide. The tissue was then triturated after which a trypsin inhibitor at 4° C. was added to digest the tissue. The digested tissue was then filtered and centrifuged. The cell pellet was then suspended in a modified Krebs Ringer buffer solution containing 500 μM Ca 2+ . To remove damaged cells and gradually increase Ca 2+ , three gravity sedimentations were done in 500 μM, 1 mM, and 1.4 mM Ca 2+ at 37° C. The cells were then suspended in tissue culture medium containing 5% fetal calf serum and 1.4 mM Ca++ in 17 mm diameter wells.
The cells were cultured for 48 hours, after which they were washed and modified Krebs Ringer buffer solution containing 5% fetal calf serum and 1.4 mM Ca in 17 mm diameter wells was again added to the wells. In test wells either 100 mM reagent grade hydrogen peroxide or a mixture of xanthine 400 mM and xanthine oxidase 8.8 mU was added with or without a test compound. Wells to which none of these agents were added served as "controls." In other wells a detergent, polyoxyethylene (10) octyphenyl ether, which causes lysis of all cells, was added.
The degree of cell damage was measured as a cell injury index (CII) calculated according to the following equation:
CII(%)= (A-B/(C-B)!×100
where "A" is the lactate dehydrogenase activity in the medium in the test wells; "B" is the lactate dehydrogenase activity in the medium in the "control" wells; and "C" is the lactate dehydrogenase activity in the medium in the wells containing polyoxyethylene (10) oxtyphenyl ether.
Using the methods described above, the lactate dehydrogenase release from the cultured myocardial cells can be determined for specified treatment conditions for various periods of time, the corresponding CII value determined and the individual results calculated at each time period.
Results
Examples of the usefulness of the test compounds are shown below with the results summarized in Tables 1 and 2. Table 1 shows the cell-protective effect of bucillamine or Compound A on myocardial cells exposed to hydrogen peroxide and Table 2 shows the protective effect of bucillamine on myocardial cells exposed to hydrogen peroxide and superoxide radical generated by xanthine/xanthine oxidase.
Each result shown in Table 1 represents a mean value from two experiments performed in triplicate (n=6 wells). Exposure to hydrogen peroxide without either test compound present resulted in a CII of 81.6% at the end of 4 hours and lesser degrees of injury at 1 or 2 hours. However, addition of either bucillamine or Compound A markedly reduced the CII at 4 hours and also reduced CII at exposure times of 1 or 2 hours. The degree of protection afforded by bucillamine or Compound A depended upon the concentration of the compound added. This verifies that bucillamine or Compound A inhibited the release of lactate dehydrogenase from cultured myocardial cells due to injury caused by exposure to hydrogen peroxide.
TABLE 1______________________________________ Degree of Cell Damage (%) 1 hour 2 hours 4 hours______________________________________No test compound present 36.5 74.7 81.6Bucillamine 125 μM 17.8 32.6 41.0250 μM 7.6 16.9 17.9500 μM 3.9 6.6 8.8Compound A 125 μM 25.1 31.6 40.1250 μM 10.6 16.9 20.2500 μM 9.1 11.0 13.8______________________________________
TABLE 2______________________________________ Degree of Cell Damage (%) 1 hour 2 hours 4 hours______________________________________No test compound present 0.7 10.3 62.1Bucillamine 125 μM 1.0 0.3 17.6250 μM 0.9 -1.5 4.3______________________________________
Each result in Table 2 is the mean value from experiments which were performed in triplicate on three separate occasions (n=9 wells). When no test compound was present, exposure to xanthine/xanthine oxidase resulted in substantial cell damage (CII 62.1%) after 4 hours but little damage earlier. When bucillamine was added, the degree of cell damage at 4 hours of exposure to xanthine/xanthine oxidase was lowered substantially. The degree of protection depended upon the concentration of bucillamine. This verifies that bucillamine inhibited the release of lactate dehydrogenase from cultured myocardial cells due to injury caused by exposure to xanthine/xanthine oxidase, which causes generation of hydrogen peroxide and superoxide radical.
As has been demonstrated in the two examples above, the test compounds prevent myocardial cell damage caused by exposure to reactive oxygen species. Reactive oxygen species are produced when hearts or other organs are reperfused after transient ischemia.
The compounds of this invention can inhibit the release of lactate dehydrogenase from cultured myocardial cells due to injury caused by exposure to xanthine/xanthine oxidase, which causes generation of hydrogen peroxide and superoxide radical. The compounds of this invention are useful for treatment of myocardial infarctions, cerebral infarctions or other conditions in which an interruption of blood flow to an organ is treated by reperfusion. They are also useful for prevention of forms of vascular injury in which reactive oxygen species are involved, including exposure to ischemia and reperfusion and development of atherosclerosis. Because there is evidence that reactive oxygen species are a cause of heart failure, independently of the presence of ischemia and reperfusion, the compounds of this invention are also useful for the prevention or treatment of this condition. Because there is evidence that generation of superoxide radical or other reactive oxygen species cause tolerance to nitroglycerine and related compounds, the compounds of this invention are also useful for the prevention or treatment of this condition.
Certain compounds of this invention have been demonstrated in the test method described above to be significantly more effective than MPG in preventing cell injury. Exemplary results are shown in FIGS. 1 and 2 for bucillamine and Compound A, respectively, compared to MPG, employing a cell injury index based on release of LDH from cells damaged by H 2 O 2 . These results indicate that both bucillamine and Compound A are about twice as effective (on a weight basis) as MPG.
The ability of compounds to prevent injury by hydrogen peroxide or other reactive oxygen species in cultured cardiac myocytes is predictive of the ability of these compounds to prevent reperfusion injury in intact hearts in animals. For example, dimethylthiourea and MPG were effective in preventing injury due to hydrogen peroxide in cultured cardiac myocytes Am. J. Physiol (1994) 266:H121-H127! and both were also effective in reducing myocardial infarct size in canine hearts exposed to ischemia and reperfusion Circ. Res. (1991) 68:1652-1659); Circulation (1994) 89:1792-1801!.
The compounds of this invention are commercially available or can be prepared by well known techniques from readily available starting materials. U.S. Pat. Nos. 4,305,958 and 5,292,926 provide details of the preparation of these compounds.
The compounds of this invention can be administered either orally or parenterally. Oral dosage forms of the compounds of the invention include tablets, capsules, granules, powders, etc., all of which can be readily prepared by known techniques. Oral dosage forms can be formulated optionally with vehicles, lubricants, binders, disintegrators and coating agents, all appropriately chosen for the particular application. Parenteral dosage forms are prepared using known techniques with appropriate buffered vehicles. Dosage of the compounds of this invention can be determined as is understood in the art depending on the condition and age of the patient and the dosage form chosen.
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 without departing from its spirit and scope. All of the references cited herein are incorporated by reference in their entirety herein. These references provide among other things details of assays and sources of compounds of this invention.
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Bucillamine and N-2,2-dimethyl-3-mercaptopropionyl)-L-cysteine or related compounds can be used to prevent damage to living tissue from the formation or presence of reactive oxygen species. These reactive oxygen species are formed when tissue is first rendered hypoxic due to interruption of blood flow and then reoxygenated by restoration of blood flow. In particular, the invention is directed to the administration of bucillamine and N-2,2-dimethyl-3-mercaptopropionyl)-L-cysteine prior to or coincidental with reperfusion to prevent damage to myocardium from formation of reactive oxygen species. Also presented are application of these compounds to similar ischemia-related cell injury in other organs.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application Ser. No. 61/584,130 filed on Jan. 6, 2012, which is hereby incorporated by reference in its entirety and for all purposes.
BACKGROUND
Semiconductor and other thin film technologies often employ heated or cooled pedestals to control the temperature of workpieces prior to, during, or after processing of the workpieces. For example, a heated pedestal may be used in a processing chamber to heat and maintain a predetermined temperature of a workpiece during deposition of a layer onto the workpiece, removing materials from the workpiece surfaces, or performing other processing operations. Heated or cooled pedestals may also be provided in load locks for heating or cooling workpieces as they are being transferred in or out of the processing environment. Such pedestals may be made of aluminum or ceramic materials and formed into a single monolithic piece. A workpiece is supported above a surface of this pedestal to achieve heat transfer (i.e., heating or cooling depending on relative temperatures of the workpiece and pedestal). A gap between the pedestal surface and workpiece provides some control to this heat transfer such that a higher heat transfer rate corresponds to a smaller gap, while a lower heat transfer rate corresponds to a larger gap (i.e., the inverse proportional relationship).
Often, workpieces, particularly large but thin wafers (e.g., 450 millimeter wafers) are deformed when introduced into a processing system and need to be heated or cooled uniformly. Some common examples of such deformations include bowing, when a workpiece has a concave shape with its center portion extending downward with respect to the plane defined by its edges; and doming, when a workpiece has a convex shape with its center portion extending upward with respect to the plane defined by its edges. Deformations may also have various non-symmetrical shapes. Deformation may occur due to coefficient of thermal expansion differences among various materials forming workpieces, compressive or tensile films deposited on their surfaces, and other factors. Often workpieces in the same batch have different kinds and levels of deformation. These deformations are hard to anticipate and often random in nature. Furthermore, some deformation may occur during heat transfer, while the workpiece is already in the system. These “in process” deformations may be due to changes in workpiece temperature, deposition of additional materials, and other reasons. As such, it is difficult, and generally may not be possible to have preset heat transfer surfaces that always conform to deformed workpieces. Generally, pedestals with planar surfaces have been used because of this relatively unpredictable nature of deformations. While pedestals with predetermined curved surfaces have been proposed, their application is limited to only very specific types of deformation.
When a deformed workpiece is positioned over a planar surface of the pedestal, the gap between that surface and the workpiece will vary throughout the surface. This variation may cause non-uniform heat transfer throughout the surface, which may result in a non-uniform temperature profile of the workpiece. The temperature variation may interfere with processing and result, for example, in uneven deposition or material removal rates throughout the surface. Further, this temperature variation may cause further deformation and, in certain cases, permanent damage of the workpiece. For example, excessive deformation may cause slip dislocations in silicon structures, when portions of silicon lattice are displaced with respect to each other. This defect may degrade the electrical performance of the device. In some cases, workpieces may even break inside the apparatus, which causes prolonged shutdowns and expensive clean-ups.
SUMMARY
Provided are adaptive heat transfer methods and systems for uniform heat transfer to and from various types of workpieces, such as workpieces employed during fabrication of semiconductor devices, displays, light emitting diodes, and photovoltaic panels. This adaptive approach allows for reducing heat transfer variations caused by deformations of workpieces.
Deformation may vary in workpieces depending on types of workpieces, processing conditions, and other variables. Such deformations are hard to anticipate and may be random.
Provided systems may change their configurations to account for the deformation of each new workpiece processed. Further, adjustments may be performed continuously or discretely during heat transfer. This flexibility can be employed to improve heat transfer uniformity, to achieve uniform temperature profile, to reduce deformation, and for various other purposes. In disclosed embodiments, systems may include sensors for measuring temperature profiles of workpieces and/or gap variations between workpieces and heat transferring surfaces of the system. Positions and/or shapes of these surfaces can then be adjusted based on the responses of these sensors.
In certain embodiments, a heat transfer system for providing substantially uniform heat transfer to or from a workpiece exhibiting deformation is provided. The heat transfer system may include first and second heat transfer portions. The first heat transfer portion may have a first workpiece facing surface and a first set of minimum contact area supports extending from the first workpiece facing surface for supporting the workpiece that exhibits deformation. The first workpiece is supported at a predetermined distance above the first workpiece facing surface. The second heat transfer portion has a second workpiece facing surface. The second workpiece facing surface is movable with respect to the first workpiece facing surface to provide uniform heat transfer. Uniform heat transfer is provided between the workpiece exhibiting deformation and first workpiece facing surface as well as between the workpiece exhibiting deformation and the second workpiece facing surface. Uniform heat transfer helps to maintain a substantially uniform temperature profile throughout an entire area of the workpiece exhibiting deformation.
In certain embodiments, the second workpiece facing surface is movable with respect to the first workpiece facing surface to conform to a non-planar shape of the workpiece exhibiting deformation. The second workpiece facing surface may be movable with respect to the first workpiece facing surface, during heating or cooling, until an average gap between the second workpiece facing surface and the workpiece exhibiting deformation is substantially the same as an average gap between the first workpiece facing surface and the workpiece exhibiting deformation.
In certain embodiments, the heat transfer system also includes a system controller for controlling movement of the second workpiece facing surface with respect to the first workpiece facing surface while heating or cooling the workpiece exhibiting deformation. The heat transfer system may also include one or more sensors provided in the second workpiece facing surface and/or the first workpiece facing surface to provide input to the control system. These sensors may be configured to sense one or more parameters, such as a temperature profile of the workpiece exhibiting deformation, a gap between the second workpiece facing surface and the workpiece exhibiting deformation, and a gap between the first workpiece facing surface and the workpiece exhibiting deformation. The heat transfer system may also include a lifting mechanism controlled by the system controller to move the second workpiece facing surface with respect to the first workpiece facing surface.
In certain embodiments, the first workpiece facing surface has a circular (e.g., ring) shape having a first radius. In these embodiments, the sensors may include a first sensor positioned in a center of the first workpiece facing surface and at one end of the first radius, a second sensor positioned at another end of the first radius, and a third sensor positioned along the first radius in between the first sensor and the second sensor. The circular shape of the first workpiece facing surface may also have a second radius positioned at an angle with respect to the first radius. Another third sensor may be positioned along this second radius. In certain embodiments, the second radius is substantially perpendicular to the first radius.
The second workpiece facing surface may be positioned above and facing the first workpiece facing surface. In these embodiments, the workpiece exhibiting deformation is positioned in between the first and second workpiece facing surfaces. The first heat transfer portion may be a part of a first pedestal, while the second heat transfer portion may be a part of a second pedestal. The first and second pedestals are provided in a processing chamber or in a load lock. In other embodiments, the first heat transfer portion may be a part of the first pedestal, while the second heat transfer portion may be a part of the shower head. The shower head may have multiple openings for supplying a precursor during processing of the workpiece exhibiting deformation.
In certain embodiments, the first and second heat transfer portions form the same pedestal. In these embodiments, the second heat transfer portion may also include a set of minimum contact area supports extending from the second workpiece facing surface for supporting the workpiece at a predetermined distance above the second workpiece facing surface. The surface area of the first workpiece facing surface may be substantially the same as the surface area of the second workpiece facing surface. In specific embodiments, the first workpiece facing surface has a circular shape having a first diameter. The second workpiece has a disk shape having an inner diameter substantially the same as the first diameter of the circular shape of the first workpiece facing surface. The heat transfer system may also include a third heat transfer portion having a third workpiece facing surface. The third workpiece facing surface may have a disk shape with an inner diameter substantially the same as an outer diameter of the second workpiece facing surface. The third workpiece facing surface is movable with respect to the first workpiece facing surface independently from the second workpiece facing surface to provide uniform heat transfer. In these embodiments, two or more heat transfer portions are arranged as nested cylinders.
In other embodiments, the first and second workpiece facing surfaces have circle sector shapes. These surfaces may form a circle together with one or more additional workpiece facing surfaces of one or more additional heat transfer portions. The one or more additional workpiece facing surfaces may be movable with respect to the first workpiece facing surface to provide uniform heat transfer. In the same or other embodiments, the first workpiece facing surface, second workpiece facing surface, and one or more additional workpiece facing surfaces are pivotable with respect to a center of the circle.
Provided also is a heat transfer pedestal for providing uniform heat transfer to a workpiece exhibiting deformation. The heat transfer pedestal may include a base support and a bendable heat transfer plate including a continuous workpiece facing surface. The continuous workpiece facing surface is configured to change its shape in order to conform to a shape of the workpiece exhibiting deformation to provide uniform heat transfer between the workpiece exhibiting deformation and the continuous workpiece facing surface upon exerting a force on the bendable heat transfer plate. The force may be exerted by changing a pressure in a space between the base support and the bendable heat transfer plate by supplying or removing a gas or a liquid from the space between the base support and bendable heat transfer plate. In the same or other embodiments, the force may be exerted by one or more mechanical structures attached to the bendable heat transfer plate and configured to move with respect to the base support.
Provided also is a method for providing uniform heat transfer to or from a workpiece exhibiting deformation. The method may involve positioning the workpiece exhibiting deformation having a non-planar shape onto a first set of minimum contact area supports that extend from a first workpiece facing surface of a first heat transfer portion. The first workpiece facing surface may be movable with respect to a second workpiece facing surface. The temperature of the workpiece exhibiting deformation may be different from the temperature of the first workpiece facing surface and the temperature of the second workpiece facing surface. The method may proceed with determining one or more parameters, such as a temperature profile of the workpiece exhibiting deformation, a gap between the second workpiece facing surface and the workpiece exhibiting deformation, and a gap between the first workpiece facing surface and the workpiece exhibiting deformation. The method may continue with adjusting a position of the first workpiece facing surface with respect to the second workpiece facing surface based on the one or more determined parameters. The workpiece exhibiting deformation may be then removed when the workpiece reaches a predetermined temperature.
In certain embodiments, the method may involve repeating determining and adjusting operations described above one or more times prior to removing the workpiece. Examples of workpieces include a semiconductor substrate, a photovoltaic substrate, and a display substrate. In certain embodiments, the temperature profile of the workpiece exhibiting deformation deviates by less than about 5° C. prior to removing the workpiece. The workpiece may exhibit less deformation at the time of removing than at the time of positioning.
In certain embodiments, a method also involves applying photoresist to the workpiece, exposing the photoresist to light, patterning the resist and transferring the pattern to the workpiece, and selectively removing the photoresist from the workpiece. In these embodiments, a semiconductor processing system may include a stepper.
These and other embodiments are described further below with reference to the figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a drawing depicting a cross-sectional view of a flat workpiece supported above a workpiece facing surface of a pedestal using minimum contact area (MCA) supports, according to embodiments.
FIG. 1B is a drawing depicting a cross-sectional view of a deformed workpiece supported above the same workpiece facing surface of the pedestal of FIG. 1A .
FIG. 1C is a schematic drawing depicting a cross-sectional view of an apparatus for processing semiconductor workpiece, in accordance with embodiments.
FIG. 2A is a schematic drawing depicting a top view of an adaptive heat transfer pedestal having three concentric cylindrical portions that are independently movable with respect to each other in the vertical direction, in accordance with embodiments.
FIG. 2B is a schematic drawing depicting a top view of an adaptive heat transfer pedestal having four sector-shaped portions, in accordance with embodiments.
FIG. 2C is a schematic drawing depicting a top view of an adaptive heat transfer pedestal having twelve portions, in accordance with embodiments.
FIG. 2D is a schematic drawing depicting a top view of an adaptive heat transfer pedestal having multiple pegs that are movable in the vertical direction with respect to a base surface, in accordance with embodiments.
FIG. 3A is a schematic drawing depicting a cross-sectional view of a segmented adaptive heat transfer pedestal having three portions aligned with respect to a plane and a flat workpiece, in accordance with embodiments.
FIG. 3B is a schematic drawing depicting a cross-sectional view of the segmented adaptive heat transfer pedestal of FIG. 3A with the outer portions raised with respect to the plane and with a concave workpiece, in accordance with embodiments.
FIG. 3C is a schematic drawing depicting a cross-sectional view of the segmented adaptive heat transfer pedestal of FIG. 3A with the outer portions lowered with respect to the plane and with a convex workpiece.
FIG. 4A is a schematic drawing depicting a top view of an adaptive heat transfer pedestal having four sector-shaped portions that can pivot about a pivot center, in accordance with embodiments.
FIG. 4B is a schematic drawing depicting a cross-sectional view of the adaptive heat transfer pedestal of FIG. 4A and a flat workpiece.
FIG. 4C is a schematic drawing depicting a cross-sectional view of the adaptive heat transfer pedestal of FIG. 4A with portions pivoted to adjust the workpiece facing surfaces to provide more conformal orientation to the concave workpiece.
FIG. 4D is a schematic drawing depicting a cross-sectional view of the adaptive heat transfer pedestal of FIG. 4A with portions pivoted to adjust the workpiece facing surfaces to provide more conformal orientation to the convex workpiece.
FIG. 5 is a schematic drawing depicting a cross-sectional view of an adaptive heat transfer system having two heat transfer portions and positioned on opposing sides of a workpiece, in accordance with embodiments.
FIG. 6A is a schematic drawing depicting a side view of a pedestal having a base support and a bendable heat transfer plate supporting a planar workpiece, in accordance with certain embodiments.
FIG. 6B is a schematic drawing depicting a side view of the pedestal of FIG. 6A with the bendable heat transfer plate bent downward in the center and a workpiece with a bowed shape, in accordance with embodiments.
FIG. 6C is a schematic drawing depicting a side view of the pedestal of FIG. 6A with the bendable heat transfer plate bent upward in the center and a workpiece with a domed shape, in accordance with embodiments.
FIG. 6D is a schematic drawing depicting a side view of a pedestal having a base support, a bendable heat transfer plate supporting a planar workpiece, and a mechanical structure for bending the bendable heat transfer plate, in accordance with certain embodiments.
FIG. 7A is a schematic drawing depicting a side view of an adaptive heat transfer system including a segmented pedestal and a system controller, in accordance with certain embodiments.
FIG. 7B is a schematic drawing of a top view of a workpiece facing structure with sensor(s), in accordance with certain embodiments.
FIG. 8 is a flowchart illustrating a method for providing uniform heating/cooling of deformed workpieces, in accordance with certain embodiments.
FIG. 9 is a schematic drawing of a top view of multi-station process apparatus that may be equipped with adaptive heat transfer systems, in accordance with certain embodiments.
FIG. 10 is a schematic drawing of a top view of a multi-chamber apparatus that may be equipped with adaptive heat transfer systems, in accordance with certain embodiment.
FIG. 11A is a graph illustrating temperature profiles of conventional flat pedestals as compared to adaptive pedestals of embodiments.
FIG. 11B is a graph illustrating temperature profiles between the center and edge portions of a conventional flat pedestal and an adaptive pedestal of embodiments.
FIG. 11C is a graph illustrating deflection profiles of a conventional flat pedestal and an adaptive pedestal of embodiments.
DETAILED DESCRIPTION
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the presented concepts. The presented concepts may be practiced without some or all of these specific details. In other instances, well-known process operations have not been described in detail so as to not unnecessarily obscure the described concepts. While some concepts will be described in conjunction with the specific embodiments, it will be understood that these embodiments are not intended to be limiting.
Introduction
A deformed workpiece is compared to a flat workpiece in FIGS. 1A and 1B . Specifically, these figures illustrate gap variations between the center and edge portions of these workpieces positioned over the planar pedestal surfaces. FIG. 1A illustrates a flat workpiece 50 supported above a workpiece facing surface 62 of a pedestal 60 using, for example, minimum contact area (MCA) supports 52 . Since both workpiece 50 and workpiece facing surface 62 are flat, the gap between is constant throughout the entire workpiece. Specifically, the gap in the center portion of workpiece 50 (identified as D 1 ) is substantially the same as the gap near the edge portion of workpiece 50 (also identified as D 1 ). This constant gap is generally determined by the height of MCA supports 52 .
FIG. 1B illustrates a deformed workpiece 54 supported above the same workpiece facing surface 62 of pedestal 60 of FIG. 1A . Workpiece 54 is bowed. As a result, the gap between its center portion and workpiece facing surface 62 (identified as D 2 ) is less than the gap between its edge portions and workpiece facing surface 62 (identified as D 3 ), i.e., D 3 >D 2 . In this example, a heat flux between workpiece 54 and workpiece facing surface 62 may be greater in the center portion than near the edges because of these gap differences. During heating of workpiece 54 , its center portion is likely to have a higher temperature than its edges. In a similar manner, during cooling of workpiece 54 , its center portion is likely to have a lower temperature than its edges. This uneven temperature distribution is further reflected below in thermal modeling results.
Adaptive heat transfer systems and methods provide uniform heating and/or cooling of deformed workpieces. A system may adjust its one or more heat transfer surfaces to provide uniform heat transfer. For example, a system may move one of its multiple workpiece facing surfaces with respect to others or to change the shape of a continuous workpiece surface facing of a bendable heat transfer plate. In certain embodiments, these adjustments result in a more conformal workpiece facing surface than the initial surface and, as a result, more uniform heat transfer.
In certain embodiments, a pedestal may include multiple concentric cylinders independently movable with respect to each other in the direction substantially perpendicular to the workpiece. In other embodiments, a pedestal may include multiple sectors that are independently pivotable with respect to, for example, the center of the pedestal. In yet other embodiments, a workpiece is positioned between two workpiece facing surfaces, which may be substantially planar and parallel to each other. Even though neither one of these two workpiece facing surfaces may be conformal to the workpiece, the combined heat transfer may be still uniform. A portion of the workpiece, which is closer to one these surfaces, will be further away from another surface and vice versa. As such, even though each surface may provide non-uniform heat transfer, a combination of their individually non-uniform heat fluxes may be uniform.
Adjustment of various hardware components may be controlled based on one or more process parameters, such as a temperature profile of the workpiece and/or a gap profile between the workpiece and one or more workpiece facing surfaces. A system controller may be used to receive input from the sensors and control one or more mechanisms used for repositioning and/or adjusting shapes of one or more workpiece facing surfaces.
Uniform heat transfer features of various pedestals described below may be used for both cooling and heating workpieces. In order to keep this document focused and concise, references are generally made to heating a workpiece. However, one having ordinary skill in the art would understand how to apply these methods and systems for cooling workpieces as well.
To better understand various features of adaptive heat transfer systems and methods, a brief description of one example of a processing apparatus is provided herein. FIG. 1C is a schematic representation of apparatus 100 for processing semiconductor workpieces, in accordance with certain embodiments. Apparatus 100 generally represents various types of equipment configured, for example, to remove photoresist materials and/or other residue materials from semiconductor workpieces, as well conduct other semiconductor processing operations. Some specific examples include the GAMMA 2100, 2130 I2CP (Interlaced Inductively Coupled Plasma), G400, GxT, and the SIERRA, all of which are available from Novellus Systems in San Jose, Calif. Other systems include the FUSION line, which is available from Axcelis Technologies in Rockville, Md.; TERA21, which is available from PSK Tech in Korea; and ASPEN, which is available from Mattson Technology in Fremont, Calif. Some processing chambers containing adaptive heat transfer systems may be associated with cluster tools. For example, a strip chamber may be added to the CENTURA cluster tool, which is available from Applied Materials in Santa Clara, Calif. Other examples include ALTUS and VECTOR, available from Novellus Systems in San Jose, Calif.
Apparatus 100 includes plasma source 101 for generating and providing energized or activated reactant species into chamber 103 . Chamber 103 may be separated from plasma source 101 by showerhead assembly 105 . A showerhead 109 forms the bottom of showerhead assembly 105 . Plasma source 101 is connected to process gas inlet 111 , which supplies one or more process gasses through showerhead assembly 105 into processing chamber 103 . A low-pressure environment is attained in processing chamber 103 via vacuum pump and conduit 119 .
Processing chamber 103 includes pedestal 117 . Pedestal 117 is used to support a semiconductor workpiece 116 and to heat and/or cool semiconductor workpiece 116 . As such, pedestal 117 may be fitted with a heating and/or cooling element. In some embodiments, pedestal 117 is also configured for applying an electrical potential bias to semiconductor workpiece 116 . Pedestal 117 is shown to include multiple heat transfer portions, which are independently movable with respect to each other in the vertical direction. Other examples are adaptive heat transfer pedestals are described below.
During processing, one or more process gases are introduced via gas inlet 111 through plasma source 101 . The gases may contain one or more chemically active species. Plasma source 101 may be used to ionize the gases in order to generate activated species and to form plasma. In the illustrated example, plasma source 101 is equipped with Radio Frequency (RF) induction coils 115 . Showerhead 109 then directs these activated reactant species into processing chamber 103 through showerhead holes 121 . Any number and arrangement of showerhead holes 121 may be used to try to maximize uniformity of distribution of the activated reactant species towards the surface of semiconductor workpiece 116 .
Pedestal 117 may be temperature controlled and used for heating semiconductor workpiece 116 . There may be some gap between pedestal 117 and semiconductor workpiece 116 during processing. The gap may be provided by MCA supports, which are further described below with reference to FIG. 1A . In certain embodiments, some contact may be allowed between the workpiece-facing surface of pedestal 117 and workpiece 116 . The gap may be increased by lowering the pedestal 117 or decreased by raising the pedestal 117 . When the pedestal 117 is lowered, semiconductor workpiece 116 is supported by pegs 123 , which may be attached to the process chamber 103 . In other embodiments, fingers of an internal robot may support the semiconductor workpiece while the pedestal 117 is in the lowered position.
Some heat flux may be provided by thermal conduction. Some additional heat flux may be provided by radiation. The relative contributions of these two heat transfer methods depend on the size of the gap between pedestal 117 and workpiece 116 , emissivity of the workpiece-facing surface of pedestal 117 , pressure inside processing chamber 103 , and other factors. In certain embodiments, thermal conduction is the largest contributor to the overall heat flux.
The apparatus/process described hereinabove may be used in conjunction with lithographic patterning tools or processes, for example, for the fabrication or manufacture of semiconductor devices, displays, light emitting diodes (LEDs), photovoltaic panels, and the like. Typically, though not necessarily, such tools/processes may be used/conducted together in a common fabrication facility. Lithographic patterning of a film typically comprises some or all of the following steps, each step enabled with a number of possible tools: (1) application of photoresist on a workpiece (i.e., using a spin-on or spray-on tool); (2) curing of photoresist using a hot plate or furnace or ultraviolet (UV) curing tool; (3) exposing the photoresist to visible, UV, or x-ray light with a tool such as a wafer stepper; (4) developing the resist so as to selectively remove resist and thereby pattern it using a tool such as a wet bench; (5) transferring the resist pattern into an underlying film or workpiece by using a dry or plasma-assisted etching tool; and (6) removing the resist using a tool such as an RF or microwave plasma resist stripper.
Independently Controllable Multiple Workpiece Facing Surfaces
In certain embodiments, an adaptive heat transfer system includes multiple heat transfer portions with each portion having a separate workpiece facing surface. Positions of these workpiece facing surfaces are adjustable with respect to each other. The position of one workpiece facing surface may be fixed with respect to a workpiece by, for example, providing a set of MCA supports extending from this surface. This surface may be used as a reference surface for adjusting positions of other surfaces.
Positions of workpiece facing surfaces are adjusted to provide uniform heat transfer between a workpiece and a combination of all surfaces. For example, workpieces may have different deformations and may need different relative positions of the workpiece facing surfaces to conform to these different deformations and to provide substantially uniform heat transfer regardless of the deformation. Uniform heat transfer may ensure a substantially uniform temperature profile throughout the entire area of the workpiece. For example, temperature deviations throughout the entire area of the workpiece may be less than about 10° C. or, more specifically, less than about 5° C. These temperature deviations may define substantially uniform heat transfer.
Multiple workpiece facing surfaces may be positioned on the same side of a workpiece and form a combined adjustable workpiece facing surface. Multiple workpiece facing surfaces may be adjusted in a direction substantially perpendicular to the plane defined by a planar workpiece (i.e., the workpiece without any deformations). This type of adjustment may be referred to as a vertical adjustment. In these embodiments, multiple workpiece facing surfaces may remain parallel to each during vertical adjustment. In other embodiments, surfaces may be positioned at an angle with respect to each other, and these preset angles may be maintained during vertical adjustment of the workpiece facing surfaces. Alternatively, multiple workpiece facing surfaces may pivot with respect to each other and/or with respect to the center of the combined surface (e.g., a center of the pedestal). These pivotable surfaces may or may not have independent vertical adjustment in addition to pivoting.
In certain embodiments, two workpiece facing surfaces are provided on different sides of a workpiece. The uniform heat transfer is ensured by a combined heat transfer between the workpiece and two surfaces. Both surfaces may be planar and be substantially parallel to each other. In certain embodiments, both surfaces may have some curvature. Furthermore, each one of the two surfaces may include multiple surfaces independently adjustable with respect to each other as further explained above. The gap between two surfaces provided on the opposite sides of the workpiece depends on the thickness of the workpiece, deformation of the workpiece, temperature of each surface, a predetermined gap between the workpiece and one of these surfaces (e.g., provided by MCA supports) and other factors. The combined heat transfer from the two surfaces ensures an even temperature profile.
Each of these embodiments will now be explained in more details with reference to corresponding figures.
Vertically Adjustable Workpiece Facing Surfaces
FIG. 2A is a top schematic view of heat transfer pedestal 200 having three concentric cylindrical portions 202 , 204 , and 206 that are independently movable with respect to each other in the vertical direction, in accordance with certain embodiments. The vertical direction is defined as a direction substantially perpendicular to the X-Y plane shown in this figure. Further, the vertical direction is substantially perpendicular to a planar workpiece when one is positioned onto pedestal 200 . Sometimes pedestal 200 or similar pedestals are referred to as segmented pedestals. However, workpiece facing surfaces of portions of these segmented pedestals may correspond to any shapes/portions of the circle and are not limited to circle segments. For example, FIG. 2A shows portion 202 having a circular shape, while portions 204 and 206 have a disk shape. FIG. 2B shows portions 212 , 214 , 216 , and 218 having sector shapes. Sometimes, portions of such segmented pedestals are referred to as segments. However, unless specifically noted, segments may have workpiece facing surfaces of any shape.
A segmented pedestal may have any number of portions, such as two, three, four, or more portions. More portions allow for forming a combined workpiece facing profile that is more conformal to deformations, such as bowing and doming, of workpieces as further explained below with reference to FIGS. 3A, 3B and 3C . However, each movable segment may use a separate lifting mechanism, which may complicate the overall system.
FIG. 2A also illustrates MCA supports 208 provided on workpiece facing surfaces of concentric cylindrical portions 202 , 204 , and 206 . MCA supports 208 may extend by the same distance from their respective surfaces and be used to prevent a workpiece from touching these surfaces. In these embodiments, the uniformity of heat transfer may be associated with the number of MCA supports that come into contact with the workpiece. That is, the higher the number of MCA supports, the more uniformity. Also, a uniform distribution of MCA supports on the surface may provide higher heat transfer uniformity. In certain embodiments, the distribution of MCA supports is such that a distance between any pair of adjacent MCA supports is substantially the same.
FIG. 2B is a top schematic view of heat transfer pedestal 210 having four sector-shaped portions 212 - 218 , in accordance with certain embodiments. A sector is defined as a part of a circle enclosed by two radii of that circle and their intercepted arc. A sector is sometimes referred to as a pie-shaped part of a circle. These four sectors form a full circle that defines the boundary of pedestal 210 . As with the previous embodiments, a segmented pedestal may have any number of such sectors, generally three or more. The four sector-shaped portions 212 - 218 are independently movable with respect to each other in the vertical direction. This heat transfer pedestal may be used for workpieces that deform asymmetrically.
FIG. 2C is a top schematic view of heat transfer pedestal 220 having twelve portions 222 a - 226 d , in accordance with certain embodiments. These twelve portions may be organized into four sector groups (e.g., a first group containing portions 222 a , 224 a , and 226 a ; a second group containing portions 222 b , 224 b , and 226 b ; a third group containing portions 222 c , 224 c , and 226 c ; and a fourth group containing portions 222 d , 224 d , and 226 d ). These groups may be viewed as sector portions of the pedestal presented in FIG. 2B . These twelve portions may also be organized into three circular groups (e.g., a first group containing portions 222 a , 222 b , 222 c , and 222 d ; a second group containing portions 224 a , 224 b , 224 c , and 224 d ; and a third group containing portions 226 a , 226 b , 226 c , and 226 d ). These groups may be viewed as circular portions of the pedestal presented in FIG. 2B . All twelve portions may be independently movable with respect to each other in the vertical direction. Specifically, heat transfer pedestal 220 may be used for workpieces that deform asymmetrically similar to the pedestal presented in FIG. 2B . However, heat transfer pedestal 220 provides additional flexibility in controlling heat transfer. In certain embodiments, portions may also be moved in the various groups described above and/or various sub-groups.
FIG. 2D is a top schematic view of heat transfer pedestal 230 having base surface 232 and multiple pegs 234 that are movable with respect to base surface 232 in the vertical direction, in accordance with certain embodiments. The vertical position of pegs 234 may be varied individually to adjust heat transfer distribution. A peg 234 may be brought closer to the workpiece to increase heat transfer in this location. In a similar manner, a peg 234 may be lowered and therefore moved away from the workpiece to reduce the heat transfer in this location. The position of pegs 234 may be controlled by sensors, which may be installed in the workpiece facing surfaces of pegs 234 . Pegs 234 may have the same temperature as base surface 232 . In other embodiments, pegs 234 have a different temperature than base surface 232 . For example, when pedestal 230 is used for heating, pegs 234 may have a higher temperature than base surface 232 . In specific embodiments, pegs 234 may be used to heat base surface 232 (i.e., base surface 232 may not have a separate heater).
The vertical adjustment of multiple workpiece facing surfaces of a pedestal will now be explained with reference to FIGS. 3A-3C , which are schematic side views of segmented pedestal 300 having three portions 304 , 306 , and 308 having three different adjustments. Pedestal 300 may be similar to the pedestal illustrated in FIG. 2A and described above. FIG. 3A illustrates pedestal 300 supporting planar workpiece 302 . Workpiece facing surfaces of all three portions 304 , 306 , and 308 are aligned with respect to plane 310 that is substantially parallel to planar workpiece 302 . The gap between these workpiece facing surfaces and workpiece 302 is constant throughout the entire surface of workpiece 302 .
FIG. 3B illustrates pedestal 300 supporting concave workpiece 312 . This workpiece has its center closer to plane 310 than its edges. As such, if workpiece facing surfaces of the three portions 304 , 306 , and 308 are aligned with respect to plane 310 , the heat transfer may be be non-uniform. There may be more heat transferred between portion 308 and the center of concave workpiece 312 than, for example, between portion 304 and the edge of concave workpiece 312 . If pedestal 300 is used for heating workpiece 312 , this non-uniformity may result in the temperature of the center of workpiece 312 being higher than the temperature of the edge of workpiece 312 . To avoid this non-uniformity, portions 304 and 306 are raised with respect to plane 310 . Further, portion 304 may be raised more than portion 306 to better conform to the shape of concave workpiece 312 .
FIG. 3C illustrates pedestal 300 supporting convex workpiece 322 . This workpiece has its center further away from plane 310 than its edges. As such, if workpiece facing surfaces of three portions 304 , 306 , and 308 are aligned with respect to plane 310 , the heat transfer may also be non-uniform. However, unlike in the example described above with reference to FIG. 3B , there may be less heat transferred between portion 308 and the center of convex workpiece 322 than, for example, between portion 304 and the edge of convex workpiece 322 . If pedestal 300 is used for heating workpiece 322 , this non-uniformity may result in the temperature of the center of workpiece 322 being lower than the temperature of the edge of workpiece 322 . To try to avoid this non-uniformity, portions 304 and 306 are lowered with respect to plane 310 . Further, portion 304 may be lowered more than portion 306 to better conform to the shape of convex workpiece 322 .
Pivotable Workpiece Facing Surfaces
Instead of or in addition to moving portions of the same pedestal in the vertical direction, these portions may be pivoted with respect to each other. In certain embodiments, a reference point used to define pivoting is the center of the pedestal. FIG. 4A is a top schematic view of pedestal 400 having four sector-shaped portions 402 , 404 , 406 and 408 in accordance with certain embodiments and may be similar to the pedestal illustrated in FIG. 2B . Portions 402 - 408 may be pivoted with respect to pivot center 410 of pedestal 400 , with respect to edges 414 of pedestal 400 , and/or with respect to interfaces 412 of adjacent portions. Hinges or other pivotable mechanisms may be provided at one or more of these locations. The overall diameter of pedestal 400 or separations between adjacent edges of portions 402 - 408 may change depending on pivoting locations. In general, a pedestal may have three or more sector-shaped pivotable portions.
The pivotable adjustment of multiple workpiece facing surfaces of the pedestal will now be explained with reference to FIGS. 4B-4D , which are schematic side views of segmented pedestal 400 showing portions 406 and 408 having three different adjustments. FIG. 4B illustrates pedestal 400 supporting planar workpiece 420 . Workpiece facing surfaces of portions 406 and 408 are aligned with the same plane, and the angle between these surfaces is about 180° with respect to center 410 of pedestal 400 . The gap between these workpiece facing surfaces and workpiece 420 is constant throughout the entire surface of workpiece 420 .
FIG. 4C illustrates pedestal 400 supporting concave workpiece 422 . Workpiece 422 has its center lower than its edges in the Z direction. As such, if workpiece facing surfaces of portions 406 and 408 are aligned with the same plane (as in FIG. 4B ), the heat transfer may be non-uniform. There may be more heat transferred between the center portion of the workpiece and pedestal than between the edge portion. If pedestal 400 is used for heating workpiece 422 , this non-uniformity may result in the temperature of the center of workpiece 422 being higher than the temperature of the edge of workpiece 422 . To avoid this non-uniformity, portions 406 and 408 are pivoted with respect to center 410 of pedestal 400 such that the angle between these workpiece facing surfaces of these portions is less than 180° with respect to center 410 . This adjustment provides more conformal orientation of the workpiece facing surfaces and more uniform heat transfer.
FIG. 4D illustrates pedestal 400 supporting convex workpiece 424 . Workpiece 424 has its center higher than its edges in the Z direction. As such, if workpiece facing surfaces of portions 406 and 408 are aligned with the same plane (as in FIG. 4B ), the heat transfer may be non-uniform. There may be less heat transferred between the center portion of the workpiece and pedestal than between the edge portion. If pedestal 400 is used for heating workpiece 424 , this non-uniformity may result in the temperature of the center of workpiece 424 being lower than the temperature of the edge of workpiece 424 . To avoid this non-uniformity, portions 406 and 408 are pivoted with respect to center 410 of pedestal 400 such that the angle between these workpiece facing surfaces of these portions is greater than 180° with respect to center 410 . This adjustment provides more conformal orientation of the workpiece facing surfaces and more uniform heat transfer.
Two Workpiece Facing Surfaces on Opposite Sides of a Workpiece
In certain embodiments, multiple heat transfer portions do not form the same pedestal or some other common body. Instead multiple heat transfer portions may be positioned apart from each other. In specific embodiments, two heat transfer portions may be positioned on opposite sides of a workpiece. A gap between these portions is adjustable to provide uniform heat transfer as further explained below. A workpiece may have a set position with respect to one portion and a variable position with respect to another portion. For example, one portion may have a set of MCA supports for supporting a workpiece. In certain specific embodiments, both portions are adjustable with respect to a workpiece.
FIG. 5 illustrates adaptive heat transfer system 500 having two heat transfer portions 504 and 506 positioned on different sides of workpiece 502 . Workpiece 502 with a concave shape is used to illustrate differences in heat transfer fluxes at different locations throughout the workpiece 502 , such as center location 510 , midpoint location 512 , and edge location 514 . Workpiece 502 has top surface 502 a facing surface 506 a of heat transfer portion 506 and bottom surface 502 b facing surface 504 a of heat transfer portion 504 .
Bottom heat transfer portion 504 may be a pedestal/platen, while top heat transfer portion 506 may be another platen, shower head, or some other component having heat transfer surface 506 a . When adaptive heat transfer system 500 is a part of a load lock, two platens may be used for two heat transfer portions 504 and 506 . When adaptive heat transfer system 500 is a part of a processing chamber, a platen may be used for bottom heat transfer portion 504 , while a shower head may be used for top heat transfer portion 506 . During heat transfer between a workpiece and the shower head used as top heat transfer portion 506 , the shower head may or may not supply gas(es) into the processing chamber.
At center location 510 , a gap between top surface 502 a of workpiece 502 and surface 506 a of heat transfer portion 506 (shown as D 1 ) is greater than a gap between bottom surface 502 b of workpiece 502 and surface 504 a of heat transfer portion 504 (shown as D 2 ). As such, a heat flux through the D 2 gap may be greater than through the D 1 gap. The temperature of workpiece 502 at center location 510 may depend on the combined heat flux through both D 2 and D 1 gaps. Any deficiencies in the heat flux through the D 1 gap may be compensated by excesses in the heat flux through the D 2 gap and vice versa.
At midpoint location 512 , a gap between top surface 502 a of workpiece 502 and surface 506 a of heat transfer portion 506 (shown as D 5 ) may be substantially the same as a gap between bottom surface 502 b of workpiece 502 and surface 504 a of heat transfer portion 504 (shown as D 6 ). As such, a heat flux through the D 5 gap may be substantially the same as through the D 5 gap. Since heat transfer portions 504 and 506 are parallel (i.e., have a constant gap between their workpiece facing surfaces 504 a and 506 a ) and since the thickness of workpiece 502 is substantially the same, the total height of the D 5 and D 6 gaps may be sufficiently the same as a the total height of the D 1 and D 2 gaps. As such, the heat flux at center location 510 may be substantially the same as at midpoint location 512 .
At edge location 514 , a gap between top surface 502 a of workpiece 502 and surface 506 a of heat transfer portion 506 (shown as D 3 ) is less than a gap between bottom surface 502 b of workpiece 502 and surface 504 a of heat transfer portion 504 (shown as D 4 ). As such, a heat flux through the D 3 gap may be greater than through the D 4 gap. The temperature of workpiece 502 at center location 510 may depend on the combined heat flux through both D 3 and D 4 . Any deficiencies in the heat flux through the D 4 gap may be compensated by excesses in the heat flux through the D 3 gap and vice versa. Further, the combination of the D 3 and D 4 gaps may be substantially the same as the combination of the D 1 and D 2 gaps, which may be substantially the same as the combination of D 5 and D 6 gaps. As such, combined heat fluxes and/or temperatures at edge location 514 may be substantially the same as at midpoint location 512 and at center location 510 .
Bendable Heat Transfer Plate Having Continuous Workpiece Facing Surface
Instead of using multiple heat transfer portions with fixed surfaces to conform to various deformations of workpieces, a heat transfer pedestal may have a bendable heat transfer plate with a continuous surface that is configured to change its shape to conform to shapes of workpieces. For example, a thin round plate may be supported along its edges with respect to the base support of the pedestal. A vertical force may be applied to a center of the plate to change its shape from planar to domed or bowed. The entire pedestal structure may have sufficient flexibility to allow for the center of the plate to move in the vertical direction with respect to the edges. The pressure may be applied by changing a pressure under the plate or pushing/pulling on the back side of the plate using some mechanical structure.
FIG. 6A is a side schematic view of pedestal 600 having base support 606 and bendable heat transfer plate 604 supporting planar workpiece 602 , in accordance with certain embodiments. Bendable heat transfer plate 604 has continuous workpiece facing surface 605 configured to change its shape to conform to a shape of workpiece 602 . In this example, planar workpiece 602 is provided above surface 605 . As such, plate 604 is not bent and surface 605 is kept planar as well to provide uniform heat transfer between workpiece 602 and surface 605 .
FIG. 6B is a side schematic view of the same pedestal 600 having base support 606 and bendable heat transfer plate 604 supporting bowed workpiece 612 , in accordance with certain embodiments. To ensure uniform heat transfer, plate 604 is bent (relative to its state shown in FIG. 6A ) such that its workpiece facing surface 605 also has a bowed shape. Plate 604 may be bent in such a way by applying a vertical downward force on the plate at least in or around the middle portion of plate 604 . This force may be applied by reducing pressure below plate 604 , such as within cavity 608 formed by plate 604 . The pressure may be reduced by pumping liquid or gas out of cavity 608 .
FIG. 6C is a side schematic view of the same pedestal 600 having base support 606 and bendable heat transfer plate 604 supporting domed workpiece 622 , in accordance with certain embodiments. In this example, plate 604 is bent such that its workpiece facing surface 605 has a domed shape to conform to the shape of workpiece 622 . Plate 604 may be bent in such a way by applying a vertical upward force on the plate at least in or around the middle portion of plate 604 by, for example, increasing pressure below plate 604 . The pressure may be increased by pumping liquid or gas into cavity 608 .
In another embodiment shown in FIG. 6D , a force is exerted by mechanical structure 639 attached to plate 634 . Specifically, pedestal 630 includes base support 636 and bendable heat transfer plate 634 supporting workpiece 632 , in accordance with certain embodiments. Plate 634 is bent by a force exerted by mechanical structure 639 , which is configured to move with respect to base support 636 . When mechanical structure 639 moves upward in the vertical direction (i.e., in the Z direction), plate 634 is bent into a domed shaped. When mechanical structure 639 moves downward in the vertical direction (i.e., in the Z direction), plate 634 is bent into a bowed shaped.
Sensors and System Controller
Adaptive heat transfer systems may include closed-loop controls for adjusting positions of multiple heat transfer portions and/or for changing the shape of continuous workpiece facing surface as described above. Closed-loop controls may include one or more sensors provided within one or more heat transfer portions or, more specifically, within one or more workpiece facing surfaces. Closed-loop controls may also include a system controller that receive inputs from these sensors and controls various mechanisms for adjustments and/or changes described above. Various examples of these closed-loop control components will now be described in more detail.
FIG. 7A is a schematic representation of adaptive heat transfer system 700 including segmented pedestal 702 and system controller 720 , in accordance with certain embodiments. Segmented pedestal 702 includes three portions 704 , 706 , and 708 and may be similar to the pedestal shown in FIG. 2A as described above. Portions 704 , 706 , and 708 are independently movable in the vertical direction (in the Z direction) by drivers 724 , 726 , and 728 . In certain embodiments, one portion has a fixed position while the other two portions are movable. Portions 704 , 706 , and 708 have sensors 714 , 716 , and 718 installed in workpiece facing surfaces of portions 704 , 706 , and 708 . Sensors 714 , 716 , and 718 may be used to detect gaps between the workpiece and workpiece facing surfaces and/or the temperature profile of the workpiece. Additional information about types of sensors and position of sensors on the workpiece facing surfaces are described below with reference to FIG. 7B .
The output of sensors 714 , 716 , and 718 is provided into system controller 720 , which determines if the vertical positions of portions 704 , 706 , and 708 need to be adjusted. For example, if system 700 is used for heating a workpiece and sensors 714 and 718 identify that the edge of the workpiece has a lower temperature than the center of the workpiece, system controller 720 may instruct corresponding drivers to raise portion 704 and/or lower portion 708 .
Drivers 724 , 726 , and 728 are sometimes referred to as actuators. In certain embodiments, drivers 724 , 726 , and 728 are servo-driven motors, which may include position feedback. Position of portions 704 , 706 , and 708 may be based on feedback from various servo mechanisms or obtained through encoders and/or potentiometers mounted to the shafts of drivers 724 , 726 , and 728 . The rotary motion of drivers 724 , 726 , and 728 could be converted to axial motion for actuation of the pedestal segments using various mechanisms, such as lead-screw and/or ball-nut arrangements.
System controller 720 may receive input from all sensors as well as from a user interface (e.g., setting temperatures). System controller 720 typically includes one or more memory devices and one or more processors. The processor may include a central processing unit (CPU) or computer, analog and/or digital input/output connections, stepper motor controller boards, and the like. In certain embodiments, system controller 720 has a user interface associated with it. The user interface may include a display screen, graphical software displays of the apparatus and/or process conditions, and user input devices such as pointing devices, keyboards, touch screens, microphones, and the like.
System controller 720 or other system controllers (e.g. system controllers 921 or 1011 ) may control one or more of the activities of adaptive heat transfer system 700 . For example, a system controller (e.g., system controller 720 ) may execute system control software including sets of instructions for controlling the timing of various processing operations, vertical positions of different pedestal portions (e.g., portions 704 , 706 , and 708 ), workpiece and pedestal portion temperatures, gaps, and other process parameters. Other computer programs may be stored on memory devices associated with system controller 720 . These programs may be used for various processing and maintenance tasks. The computer program code for controlling the processing operations can be written in any conventional computer readable programming language: for example, assembly language, C, C++, Pascal, Fortran, or others. Compiled object code or script is executed by the processor to perform the tasks identified in the program. The controller parameters relate to process conditions such as, for example, timing of the processing operations, temperature of the workpiece (as controlled by, for example, the position of pedestal portions with respect to the workpiece and/or the energy/power delivered to the pedestal), and other parameters of a particular process. These parameters are provided to the user in the form of a recipe and may be entered utilizing the user interface.
The system software may be designed or configured in many different ways. For example, various chamber component subroutines or control objects may be written to control operation of the adaptive heat transfer system necessary to carry some operations described herein.
Adjustments within an adaptive heat transfer system may be performed once for every new workpiece, generally, soon after the workpiece is provided into the system. In other embodiments, adjustments are performed multiple times, such as after predetermined intervals or continuously while the workpiece is within the system. For example, a workpiece may change it shape due to the lessening of stresses within the workpiece because of heating or cooling. Further, a workpiece may change its shape due to coefficient of thermal expansion differences and/or increasing or reducing temperature gradients during heat transfer. In these situations, an initial adjustment of the pedestal may be insufficient to maintain uniform heat transfer after these changes in shape. An adaptive heat transfer system may dynamically adjust the vertical positions of different heat transfer portions and/or shapes of the continuous workpiece facing surface of the bendable heat transfer plate. For example, if a workpiece is initially provided with a dome shape, the central pedestal portion would be initially raised. As the workpiece relaxes and takes on a flatter shape, the central pedestal segments can be gradually lowered.
FIG. 7B is schematic representation of workpiece facing surface 750 illustrating various locations of sensors throughout surface 750 , in accordance with certain embodiments. Surface 750 may be formed by a single heat transfer portion, such as a bendable heat transfer plate or one of two plates positioned on opposite sides of the workpiece. In other embodiments, surface 750 may be formed by multiple heat transfer portions, such as concentric cylinders, sectors, or base surface/peg configurations described above. Although control components are described herein with reference to certain embodiments, similar control components can be used with reference to pedestals of other embodiments.
Surface 750 may have a round shape (as shown in FIG. 7B ) or any other shape, such as a polygon shape. For simplicity, the following description refers to the round surface. Surface 750 may be defined by its center 754 and edge 752 . For round surfaces, the distance between its center 754 and edge 752 is referred to as radius.
When workpieces have substantially symmetrical domed or bowed shapes, surface 750 may have two sensors positioned along one of its radius. For example, one sensor may be positioned at center 754 , while another may be positioned at edge 752 . If such sensors are used to measure the gap, they may reflect how deformed the workpiece is. In certain embodiments, an adaptive heat transfer system may include three or more sensors provided long the same radius. For example, one sensor may be positioned at center 754 , another may be positioned at edge 752 , while yet another one may be positioned in the middle between the other two sensors. This embodiment is illustrated in FIG. 7B with points 754 , 762 , and 760 .
To profile other parts of workpieces, particularly when asymmetrically shaped workpieces are used, sensors may be distributed along multiple radii that may be at a certain angle with respect to each other. For example, one or more sensors may be positioned along the radius extending in the X direction, and one or more sensors may be positioned along the radius extending in the Y direction.
Sensors may include temperature measuring instruments employing non-contact pyrometry and/or workpiece-heat transfer surface gap measuring instruments employing optical or capacitive methods.
Processing Operations
Provided also are methods for providing uniform heating and/or cooling of deformed workpieces. FIG. 8 illustrates one example of such methods. In this example, method 800 commences with heating or cooling one or more surfaces used for heat transfer during operation 801 . A workpiece is then positioned over the one or more surfaces in operation 802 . In operation 802 , one or more additional heat transfer surfaces may be provided above the workpiece.
Process 800 continues with monitoring one or more process parameters during operation 804 . For example, a temperature profile and/or gap variations between the workpiece and one or more workpiece facing surfaces may be measured during this operation. These measurements are then used in operation 806 to adjust one or more heat transfer surfaces based on these measurements. For example, vertical positions of different heat transfer portions may be adjusted based on the temperature profile to ensure that the workpiece has a uniform temperature. These measurements and adjustments may be performed multiple times as illustrated by decision block 808 . Repetitive measurements and adjustments may be referred to a dynamic process control.
Once the workpiece is heated or cooled to a predetermined temperature and, in certain embodiments, once various other operations (deposition, etching, etc.) are performed on the workpiece, it is removed from the one or more heat transfer surfaces during operation 810 .
Various operations may be repeated for other workpieces as reflected by decision block 812 . Multiple workpieces may have different degrees and types of deformations and may necessitate adjustments of one or more surfaces.
Multi-Station Apparatus Examples
Various heat transfer system examples described above may be used in a single station apparatus or a multi-station apparatus. FIG. 9 is a schematic illustration of a multi-station apparatus 900 , in accordance with certain embodiments. Apparatus 900 includes a process chamber 901 and one or more cassettes 903 (e.g., Front Opening Unified Pods) for holding wafers to be processed and wafers that have completed the desired process (deposition, etch, etc.). Processing chamber 901 may have a number of stations, for example, two stations, three stations, four stations, five stations, six stations, seven stations, eight stations, ten stations, or any other number of stations. The number of stations in usually determined by the complexity of the processing operations and the number of these operations that can be performed in a shared environment. FIG. 9 illustrates a process chamber 901 that includes six stations 911 - 916 . All stations 911 - 916 in the multi-station apparatus 900 within a single process chamber are exposed to the same pressure environment. However, each station 911 - 916 may have individual local plasma conditions as well as individual local heating conditions achieved by dedicated plasma generators, heaters, and platen configurations. One or more adaptive heat transfer systems described above may be provided to one or more of station 911 - 916 and/or load locks 905 a and 905 b.
A workpiece to be processed in apparatus 900 is loaded from one of the cassettes 903 through one or both load locks 905 a and 905 b into the station 911 . An external robot 907 may be used to transfer the workpiece between the cassette 903 and load locks 905 a and 905 b . In the depicted embodiment, there are two separate load locks 905 a and 905 b . Load locks 905 a and 905 b are used to transfer workpieces between one pressure environment (e.g., an atmospheric pressure outside of process chamber 901 ) and another pressure environment (e.g., a much lower pressure inside process chamber 901 ). Once the pressure is equilibrated to a level corresponding to the internal environment of process chamber 901 , another transferring device (not shown) may be used to move the workpiece from load lock 905 a onto the station 911 . The same or another transferring device may be used to move a workpiece from station 916 back into load lock 905 b for removal from processing chamber 901 . An internal robot 909 may be used to transfer workpieces among processing stations 911 - 916 . Internal robot 909 may include a spindle assembly having multiple arms extending towards processing stations. Each arm may have four fingers (e.g., two fingers on each side of the arm extending towards the stations). These fingers are used to lift, lower, and position workpieces within the processing stations.
Before a workpiece is positioned onto station 911 , the corresponding arms of the internal robot 909 are positioned such that four fingers (i.e., two fingers on each side of the two adjacent arms positioned on opposite sides of station 911 ) reside within the recesses of the platen. As explained above, these recesses are adapted for receiving such fingers. The fingers may then be lifted from the recesses of station 911 to support the workpiece above station 911 and to move the workpiece onto another station. Accordingly, the recesses of other stations are also configured for receiving these fingers. Overall, the recesses of any station are configured to receive any set of fingers of internal robot 909 . Internal robot 909 and the pedestals of stations 911 - 916 are configured to move vertically with respect to each other in order to raise the workpiece above the pedestals' surfaces or to position the workpiece onto the pedestals' surfaces. It would be understood by one having ordinary skills in the art that positioning the workpiece onto a pedestal's surface may or may not involve a direct contact between substantial portions of these components. For example, a pedestal may be equipped with a MCA support to prevent excessive contact with the back side of the workpiece. For purposes of describing overall semiconductor processing apparatus embodiments and processing embodiments, the workpiece is said to be positioned on the pedestal even though it is supported by the MCA supports. Furthermore, internal robot 909 and the pedestals of stations 911 - 916 are configured to move rotationally with respect to each other in order to move workpieces from one station to another. Since all stations are present in the same environment, there is no need for load locks or other types of transfer ports in between the stations. One workpiece may be processed (including heating) on each station or a selected sub-set of stations.
One station (e.g., station 911 ) may be reserved for the initial heating of the newly received workpiece wafer. This station may be equipped with a heating lamp positioned above the station. The initial temperature of the workpiece may be around room temperature (e.g., about 25° C.). The temperature after this pre-heating operation may exceed 300° C. and is generally determined by the subsequent operation, such deposition or etching. Various heat transfer systems described above may be used for this station. For example, a system with heat transfer portions positioned on opposites sides of the workpiece may be used on this station since no processing is performed on this station.
Other stations (e.g., stations 912 , 913 , 914 , 915 , and 916 ) may be used for other types of processing. Processing on multiple stations in the apparatus may be performed sequentially or in parallel. In certain embodiments, all or some selected processing stations of apparatus 900 may have adaptive heat transfer systems. As noted above, some or all of the processing stations may be provided with their own RF power supply, such as a downstream inductively coupled plasma RF source. These stations may also be equipped to apply a bias to a workpiece positioned on the pedestal surface. Furthermore, some or all of the platens may be equipped with a heating element. Various heat transfer systems described above may be used for these stations as well.
Different stations may have pedestals at different vertical positions with respect to internal robot 909 . For example, stations 912 and 913 may have their pedestals residing in lowered positions to have lower heat transfer fluxes from these pedestals. These stations may be used, for example, to etch an implanted crust from a photoresist. Thus, there may be a gap between the workpieces and pedestals during this operation to keep the workpieces at lower temperatures than during other operations performed on other stations. This gap may be between about 0.1 inches and 3 inches or, more specifically, between about 1.5 inches and 2.5 inches. The gap may be selected and/or adjusted during processing based on one or more factors, such as the emissivity of a wafer-facing surface of the platen, temperature of the platen, initial temperature of the wafer when it is transferred to the station, wafer temperature requirements during the operation, thermal budget of the wafer, resistivity of the wafer, type of the layers on the workpiece, and other process parameters. A lowered position of the pedestal is defined as any position where the pedestal (i.e., its workpiece-facing surface or MCA supports) is not in contact with the workpiece. These differences in the vertical orientations of the pedestals (i.e., between the raised and lowered positions) allows for achieving different workpiece temperatures while maintaining substantially similar pedestal heating configurations (both in terms of the pedestals' structures and heating elements' output). Alternatively, different stations may have different types of adaptive heat transfer systems or the same type of adaptive heat transfer systems that are configured differently. In the same or other embodiments, these pedestals may be made from less thermally conductive materials. Furthermore, the heaters' outputs may be controlled to achieve different workpiece temperatures.
One example of an etch process called high dose implant strip (HDIS) using multi-station apparatus 900 will now be briefly described. In this process, the workpiece is coated with a layer of photoresist that has been used to mask designated areas of the said workpiece during a process to implant dopants. Subsequent to the dopant implant, it is required that the remaining photoresist be etched or removed from the workpiece in preparation for subsequent processing steps. Due to the implant process, photoresist layers that have masked the designated areas of the workpiece develop a hardened crust on the outside, while retaining a softer bulk photoresist on the inside. A workpiece is first positioned on station 911 , with its pedestal in a raised position, and heated to a temperature of between about 120° C. and 140° C. When the workpiece is moved to station 912 and then to station 913 , the pedestals of these stations are in lowered positions so that the workpiece does not contact these pedestals and the heat transfer is minimized. Alternatively, one or both pedestals of stations 912 and 913 may be raised during a part of or the entire processing. In certain embodiments, these pedestals are configured to maintain the temperature of the workpiece at the same level (e.g., between about 120° C. and 140° C. reached on station 911 ) while the photoresist crust is etched. Then the workpiece is moved to station 914 to start bulk stripping. The workpiece temperature may need to be increased to at least about 250° C. or, more specifically, to about 280° C. The pedestal of this station may be in a raised position.
In certain embodiments, an apparatus is used to process different workpiece types. For example, the same apparatus may be used to strip “un-crusted” photoresist, which generally requires high-temperature conditions, and crusted photoresist, which needs lower temperature conditions. Switching between these different temperature operating regimes may use different configurations of adaptive heat transfer systems. This structural change of the apparatus may be coupled with changes in heater outputs and/or the vertical position of the pedestal.
In certain embodiments, a system controller 921 is used to control process conditions for various operations of the stripping process described below. For example, system controller 921 may control positions of the pedestals in each station 911 - 916 as well as their heater outputs and various parameters of adaptive heat transfer systems described above.
Multi-Chamber Apparatus Example
FIG. 10 is a schematic illustration of a multi-chamber apparatus 1000 that may be equipped with adaptive heat transfer systems, in accordance with certain embodiment. Apparatus 1000 may have three separate chambers 1001 , 1003 , and 1005 (as shown) or any other number of chambers. Each chamber 1001 - 1005 has its own pressure environment, which is not shared with other chambers. For example, chamber 1001 may operate at a different pressure level than chambers 1003 and 1005 or have a different chemical composition in its environment. This provides additional processing flexibility, but also requires transferring workpieces through transfer ports between different operating environments in order to prevent cross-contamination between these environments. Specifically, FIG. 10 illustrates each chamber having two load locks (i.e., chamber 1001 having a set of load locks 1021 , chamber 1003 having a set of load locks 1023 , and chamber 1005 having a set of load locks 1025 ). It should be understood that any number of load locks may be used for each individual chamber. Load locks 1021 - 1025 may be exposed to an intermediate environment 1031 , which may be different than the ambient environment of storage cassettes 1009 , and be separated from storage cassettes 1009 by a set of load locks (not shown). Furthermore, one or more chambers 1001 - 1005 may share its environment with intermediate environment 1031 and, therefore, one or more corresponding load lock sets 1021 - 1025 may be omitted or kept open on both sides.
FIG. 10 shows each chamber equipped with two stations. However, any number of stations may be used. In one embodiment, one or more chambers of the multi-chamber apparatus may be similar to the six-station examples described above with reference to FIG. 9 . Each chamber does not have to have the same number of stations. One or more stations of multi-chamber apparatus 1000 have adaptive heat transfer systems as described above. In certain embodiments, all of the stations in one of the chambers or in all chambers have adaptive heat transfer systems. Adaptive heat transfer systems may be positioned on any one of the processing chambers or load locks.
Multi-chamber apparatus 1000 may also have a shared workpiece handling robot 1007 for transferring wafers between load locks 1021 - 1025 and one or more cassettes 1009 or some other components. Each chamber, and even each individual station, may be controlled by a system controller 1011 , which may be configured similar to the ones described above with reference to FIG. 9 .
Experimental/Modeling
Modeling tests were performed to compare adaptive pedestals to conventional static pedestals. Silicon wafers having a diameter of 450 mm and a 1 millimeter initial domed deformation were used for modeling. The starting temperature was 350°. The temperature was initially uniform throughout the substrate.
One model involved a conventional flat substrate maintained at a temperature of 25° C. The substrate was positioned at a distance of about 254 micrometers from the substrate. Because of the domed deformation, the edge of the substrate was 1 millimeter closer to the pedestal surface than the center of the substrate. Another model involved an adaptive pedestal with three concentric cylindrical portions. The center portion had a diameter of 150 millimeters, the middle portion had an outer diameter of 300 millimeters, and finally the edge portion had an outer diameter of 450 millimeters. The inner diameter of the middle portion was substantially the same as the diameter of the center portion, while the inner diameter of the edge portion was substantially the same as the outer diameter of the middle portion. All three portions were kept at 25° C.
The three portions of the pedestal were adjusted to follow the profile of the substrate. That is, the center portion was raised by 1 millimeter with respect to the edge portion, and the middle portion was raised by 0.5 millimeters with respect to the edge portion.
These models were used to simulate cooing of the substrates for 10 minutes. The temperatures of substrate edges and centers were monitored during this time. Furthermore, deflection of both substrates was estimated during this period.
FIG. 11A illustrates four temperature profiles during the first 10 minutes of the modeling. Line 1102 is a temperature profile of the center portion of the substrate cooled using the conventional flat pedestal. Line 1104 is a temperature profile of the edge portion of the substrate cooled using the adaptive pedestal. Line 1106 is a temperature profile of the center portion of the substrate cooled using the adaptive pedestal. Line 1108 is a temperature profile of the center portion of the substrate cooled using the conventional pedestal. Clearly, lines 1104 and 1106 are much closer to each other than lines 1102 and 1108 , which indicates that the substrate cooled using the adaptive pedestal had a much more uniform temperature profile that the substrate cooled using the conventional flat pedestal.
The difference in performance is even more evident from FIG. 11B that illustrates two profiles of temperature differences between the center and edge portions for the two substrates. Line 1112 corresponds to the substrate cooled using the conventional flat substrate, while line 1114 corresponds to the substrate cooled using the adaptive pedestal described above. At some point during modeling, the center of the substrate cooled with the conventional flat substrate was 48° C. hotter than the edge. The temperature deviation for the substrate cooled with the adaptive pedestal was generally less than 10° C.
FIG. 11C illustrates modeled deflection profiles for the two substrates. Line 1122 represents deflection of the substrate cooled using the conventional flat substrate, while line 1124 represents deflection of the substrate cooled using the adaptive pedestal described above. Initially, both substrates had a deflection of about 1 millimeter. Deflection of the substrate cooled using the adaptive pedestal was actually reduced to about 0.6 millimeters during cooling. At the same time, deflection of the substrate cooled using the conventional flat pedestal increased and peaked at about 2.2 millimeters during cooling.
Although the foregoing concepts have been described in some detail for purposes of clarity of understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the appended claims. It should be noted that there are many alternative ways of implementing the processes, systems, and apparatuses. Accordingly, the present embodiments are to be considered as illustrative and not restrictive.
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Provided are adaptive heat transfer methods and systems for uniform heat transfer to and from various types of workpieces, such as workpieces employed during fabrication of semiconductor devices, displays, light emitting diodes, and photovoltaic panels. This adaptive approach allows for reducing heat transfer variations caused by deformations of workpieces. Deformation may vary in workpieces depending on types of workpieces, processing conditions, and other variables. Such deformations are hard to anticipate and may be random. Provided systems may change their configurations to account for the conformation of each new workpiece processed. Further, adjustments may be performed continuously of discretely during heat transfer. This flexibility can be employed to improve heat transfer uniformity, achieve uniform temperature profile, reduce deformation, and for various other purposes.
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This application is a continuation of application Ser. No. 555,528 filed Nov. 28, 1983, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an apparatus for determining the alignment accuracy of an ophthalmic instrument, and in particular to an apparatus capable of determining the accuracy of alignment between a pre-aligned eye to be examined and ophthalmic instrument and further effecting fine adjustment of the alignment.
2. Description of the Prior Art
When a light flux is to be projected onto an eye to be examined to thereby measure the refractive power or the like of the eye, unless alignment of the ophthalmic instrument and the eye to be examined is accurately effected, a measurement error may not only occur but it also may not be possible to obtain a photograph for use as a determination material when it is desired to effect determination of characteristics of the eye with a photograph or the like. Therefore, in an ophthalmic instrument, for example, a target mark for alignment is projected onto the eye to be examined, a corneal-reflection image (virtual image) formed by corneal reflection is caused to be imaged in a television camera while, at the same time, a target mark fixed to the ophthalmic instrument is caused to be imaged on the same picture plane, and the two images are made coincident with each other, thereby accomplishing alignment.
However, when the eye to be examined is continually moving, an error may sometimes occur to the measurement value due to displacement resulting from a time delay until the measurement is made even if alignment is effected.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an apparatus which is capable of discriminating the quality of the accuracy of alignment with the eye to be examined during measurement of the eye.
It is a further object of the present invention to provide an ophthalmic instrument in which a target mark for eye measurement functions also as a target mark for determining the quality of the accuracy of alignment with the eye to be examined.
It is a still a further object of the present invention to provide an apparatus in which a line sensor such as a CCD or a photodiode is used as a photodetector and the quality of the accuracy of alignment with the eye to be examined in horizontal, vertical and longitudinal directions is automatically discriminated.
The present invention will become fully apparent from the following detailed description thereof taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view of the construction of an optical system and a control circuit showing an embodiment of the present invention.
FIGS. 2 and 3 are plan views of projection charts for eye measurement and alignment, respectively.
FIGS. 4, 5 and 6 are plan views showing the positional relation between a line sensor and the corneal reflection images of the projection chart.
FIGS. 7 and 8 show the output waveforms when the line sensor is and is not aligned in the direction of the optic axis.
FIG. 9 is a plan view showing the positional relation between a line sensor in another embodiment and the corneal reflection images of a projection chart.
FIG. 10 shows the output waveform of the line sensor of the embodiment shown in FIG. 9.
FIG. 11 is a plan view showing the positional relation between a light-receiving element in still another embodiment and the corneal reflection images of a projection chart.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIG. 1, a light from a measuring projection chart 2 illuminated by a light source 1 is projected onto the fundus of an eye 7 to be examined through a lens 3, beam splitters 4, 5 and an objective lens 6. The light reflected from the fundus of the eye is transmitted through the objective lens 6 and the beam splitter 5 and is reflected by the beam splitter 4, whereafter it is detected by a light receiver 10 via a lens 8 and a light-receiving mask 9. The refractive power of the eye is found on the basis of the light detected by the receiver.
On the other hand, of the light from the chart 2, the light flux reflected by the cornea of the eye 7 to be examined passes through the objective lens 6 and is reflected by the beam splitter 5, whereafter it is reflected by a beam splitter 11 and projected by a lens 17 onto a light-receiving element, for example, a line sensor 18 such as a CCD. The light-receiving element 18 is rendered optically conjugate with the corneal reflection image position by the objective lens 6 and the lens 17. If the projection chart is a slit having openings in three directions as shown in FIG. 2 and the line sensor 18 is disposed relative to corneal reflection images 2a' and 2b' as shown in FIG. 4, vertical and horizontal deviations of alignment are detected from the positional relation between the two images 2a' and 2b' on the line sensor and longitudinal deviation of alignment is detected from blur.
Now, the standard for the alignment operation is as follows: the front portion of the eye to be examined is illuminated by light sources 16a and 16b and projected onto the light-receiving surface of a television camera 13 by the use of the objective lens 6 and relay lens 12. Simultaneously therewith, the image 14a' of the target mark 14a of a chart 14 shown in FIG. 3 which is illuminated by a light source 15 is made coincident with the corneal reflection images 16'a and 16'b of light sources 16a and 16b for illuminating the front eye portion, whereby the vertical and horizontal positions are adjusted and the longitudinal position is adjusted so that the corneal reflection images 16'a and 16'b are formed with smallest size. That is, the alignment accuracy obtained by effecting pre-alignment by this means is discriminated by the use of the present invention.
The positional relation between the line sensor 18 and the corneal reflection images 2a' and 2b' of the slits of the chart 2 will now be described in detail by reference to FIG. 4. This Figure shows the state when the eye to be examined and the apparatus according to the present invention have been properly aligned. In FIG. 4, l designates the optic axis of the optical system of the present apparatus and, when proper alignment has been achieved, the corneal reflection images 2a', 2b' and 2c' are in a point-symmetrical relation about the optic axis l. The line sensor 18 is disposed at a position deviated by y from the X-axis so that it is equal in horizontal measure relative to the XY coordinates having l as their origin and that in the vertical relation, it crosses the vicinity of the centers of the corneal reflection images 2a' and 2b'. Of course, detection of any alignment deviation would also be possible with an arrangement other than that shown in FIG. 4, but the arrangement of this Figure is more advantageous in respect of signal processing, detection range, etc. Further, it is desirable that the center n c of the line sensor be properly disposed relative to the Y-axis, but the interval per 1 bit of the line sensor is narrow and therefore, the center of the line sensor is sometimes not properly disposed. In such cases, the amount of deviation may be pre-measured and input by a digital switch or the like for correction.
Now, assuming that the line sensor 18 is divided into n o to n z , for example, 256 bits, the image 2a' is formed at an address n x and the imge 2b' is formed at an address n y . The output in this state is shown in FIG. 7. The waveform is formed by two pointed crests having their peaks respectively at the address n x and the address n y , and the peak level thereof is e. The addresses n x and n y are symmetrical relative to the center n c and thus, n c -n x =n y -n c and the interval d=n y -n x between n x and n y is of a predetermined width. This width d is pre-stored as a reference value in a ROM to be described later.
Description will now be made of cases where alignment of the eye to be examined and the present apparatus has not been properly effected. A first case is that where deviation occurs in the horizontal direction. If a deviation of Δ occurs as shown in FIG. 5, the output of the line sensor has its peaks deviated to n x' and n y' and d'=n y' -n x' remains unchanged. If the mid-point between n x' and n y' is n c' , n c' -n x' =n y' -n c' and n c -n c' =Δ.
Second, a case where deviation has occurred in the vertical direction is shown in FIG. 6. If a deviation of Δ' occurs, the output of the line sensor has its peaks deviated to n x" and n y" and the interval d"=n y" -n x" therebetween increases or decreases relative to the interval d=n y -n x when proper alignment has been achieved and therefore, it is compared with the reference value d stored in the ROM, whereby the deviation is detected. The amount of deviation Δ' can be calculated as
Δ=(d-d"/2)·tan θ
if the angle formed between the corneal reflection images 2a', 2c' and 2b', 2c' is θ.
Third, where deviation has occurred in the longitudinal direction (the direction of the optic axis), the corneal reflection images blur on the line sensor and therefore, the output of the line sensor assumes a blunted waveform in which the peak level e' is low as shown in FIG. 8.
In the manner described above, the amounts of deviation of alignment in the three-dimensional directions may be detected. If the allowable ranges of the horizontal deviation Δ and the vertical deviation Δ' are previously stored in a memory and the allowable value of the peak level reduction is determined to be e s resulting from longitudinal deviation, when measurement has been effected in an alignment state in which the allowable ranges have been exceeded, a display device 29 is caused to display a warning, thereby urging a re-measurement.
Turning back to FIG. 1, a signal control circuit 30 will be described hereinafter. The output of the line sensor 18 is amplified by an amplifier 19, is converted into a digital signal by an A/D converter 20 and is transferred to RAM 24 via the bus line 21 of a microcomputer. Reference numeral 22 designates the microcomputer MPU and reference numeral 23 denotes a ROM which drives a line sensor control circuit 26 through an interface 25. Reference numeral 27 designates a letter signal generator, and reference numeral 28 denotes a mixing circuit for mixing video signals and letter signals.
When the eye to be examined is measured by the present apparatus, part of the measuring light is reflected by the cornea of the eye, that corneal reflection image is projected onto the line sensor 18, and the light and dark portion of the image are accumulated in the sensor 18. Subsequently, a sensor read-out signal is applied to the sensor control circuit 26, and an analog signal corresponding to the light and dark portions accumulated in the sensor 18 is A/D-converted and stored in the RAM 24. MPU 22 reads out the content of the RAM 24 and calculates what position on the sensor 18 is bright, and also calculates the level of the brightness. The details of the detection of alignment deviations are as previously described. That is, the address and level of brightness of the corneal reflection image on the sensor 18 are compared with the reference value stored in the ROM 23, whereby the amounts and directions of deviation of alignment in the vertical, horizontal and longitudinal directions can be calculated. When measurement has been effected in the state in which the amount of deviation in each direction has exceeded the allowable value, the display device 29 is caused to display the measurement data and display a warning to the effect that the alignment has no been proper. That is, letters or symbols are generated by the letter generator 27 and the letters or symbols are displayed on a part of the video image of the front eye part by the mixing circuit 28. When the alignment deviation is great and the reliability of the measured value has been remarkably reduced, the measurement data is not displayed but an instruction for re-measurement is displayed. For example, the instruction may be: "Longitudinal alignment has been deviated. Align properly once again and effect re-measurement.
Alternatively, as an alignment index, use may be made of 100 for the case where proper alignment has been effected, and the amounts of deviation in the respective directions may be added up and applied to a predetermined formula, whereby 85 or 90 may be displayed. When the index is 70 or less, it may be designated as a case which requires re-measurement.
FIG. 9 shows another embodiment which is similar in general construction to the first embodiment except for the pattern of the slits of the chart 2. In this embodiment, two slits are disposed in each direction and corneal reflection images 2a', 2a" and 2b', 2b" are formed on the line sensor. The output of the line sensor in this state is shown in FIG. 10.
The curvature of the cornea will now be considered. The curvature of the cornea differs from person to person and in many eyes to be examined, it is about R 7.6 mm, but it is greater or smaller in some eyes. In the first embodiment, if the curvature of the cornea varies, the imaging magnifications of the corneal reflection images 2a' and 2b' also vary though slightly, and the interval d=n y -n x calculated from the output of the line sensor also varies. In many eyes to be examined, this variation is not so great that it affects the detection of alignment deviation, and the present embodiment can cope with eyes to be examined having curvatures of cornea greater or smaller than the normal curvature of cornea. That is, if the curvature of cornea of the eye to be examined varies, the interval Q varies in FIG. 10 while, at the same time, P and R also vary. When alignment is proper, P=R. Generally, there is established a predetermined relation between the curvature of cornea and (P/Q) or (P+Q+R/Q) and therefore, it is possible to effect correction by using this even when the radius of curvature of the cornea differs greatly from the standard (about 7.6 mm).
FIG. 11 shows still another embodiment. A chart 2' identical or similar in shape to the chart 2 in FIG. 2 is disposed on a light-receiving element 18. The light-receiving element 18 is a single element such as a photodiode and the light-receiving surface thereof covers the slits 240 a, 2'b and 2'c of the chart 2'. If alignment deviates by Δ, the corneal reflection images 2a', 2b' and 2c' will deviate from the slits 2'a, 2'b and 2'c and the output of the light-receiving element 18 will be reduced. Also, if alignment deviates in the longitudinal direction, each corneal reflection image will blur and again the output of the light-receiving element will be reduced. That is, the output of the light-receiving element becomes maximum when alignments in all of the horizontal, vertical and longitudinal directions have been effected properly. Accordingly, a warning representing unsatisfactory alignment can be put out when the output of the light-receiving element has become less than a certain level. In this embodiment, although the direction and amounts of deviation cannot be detected, there is merit in that the apparatus can be made inexpensively and with a simple construction.
Further, if, although not shown, as an improvement over the present embodiment, three light-receiving elements 18a, 18b and 18c identical or similar in construction are disposed correspondingly to the slits 2'a, 2'b and 2'c, respectively, it will also become possible to detect the directions of deviation.
Thus, the present apparatus capable of determining the alignment accuracy has the following advantages:
1. It effects the determination of the alignment accuracy by the eye measuring light flux and therefore, as compared with an apparatus provided with a separate projection optical system for determining the alignment accuracy, it suffers from no deviation of the projected light flux and can be high in accuracy. Also, the measurement data provides material for directly judging in what position of the eye to be examined the measurement hs been carried out, and can be used for the judgment of propriety, the obtainment of a reliability coefficient, the correction of error, etc.
2. Since the determination is effected by the use of the information at the moment when actual measurement has been effected, it is possible to effect error-free determination even for quick movement of the eye.
3. The fact that determination of the vertical, horizontal and longitudinal directions can be achieved by a single line sensor leads to the provision of a simple apparatus.
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An ophthalmic instrument for effecting eye measurement with an eye-measuring target mark projected onto an eye to be examined, includes a photodetector provided at a position optically conjugate with the position of the corneal reflection image of the eye-measuring target mark to thereby determine the quality of the accuracy of alignment with the eye to be examined.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. provisional application Ser. No. 62/491,258, titled “AUTOMATED CONTACT CENTER AGENT MOBILE DEVICE CLIENT INFRASTUCTURE TESTING” and filed on Apr. 28, 2017, and is also a continuation-in-part of U.S. application Ser. No. 15/613,168 titled “SYSTEM AND METHOD FOR AUTOMATED CONTACT CENTER AGENT WORKSTATION TESTING”, filed on Jun. 3, 2017, which claims benefit of U.S. provisional application 62/491,252, titled “SYSTEM AND METHOD FOR AUTOMATED CONTACT CENTER AGENT WORKSTATION TESTING” and filed on Apr. 28, 2017, which is also a continuation-in-part of U.S. application Ser. No. 15/491,965, titled “SYSTEM AND METHOD FOR AUTOMATED THIN CLIENT CONTACT CENTER AGENT DESKTOP TESTING” and filed on Apr. 19, 2017, which is a continuation-in-part of U.S. patent application Ser. No. 15/083,259 titled “SYSTEM AND METHOD FOR AUTOMATED END-TO-END WEB INTERACTION TESTING”, filed on Mar. 28, 2016, which is a continuation-in-part of U.S. patent application Ser. No. 14/854,023, titled “SYSTEM AND METHOD FOR AUTOMATED CHAT TESTING”, filed on Sep. 14, 2015, which is a continuation of U.S. patent application Ser. No. 14/141,424 titled “SYSTEM AND METHOD FOR AUTOMATED CHAT TESTING”, filed on Dec. 27, 2013, now issued as U.S. Pat. No. 9,137,184 on Sep. 15, 2015, which is a continuation of U.S. patent application Ser. No. 13/936,186 titled “SYSTEM AND METHOD FOR AUTOMATED CHAT TESTING”, filed on Jul. 6, 2013, and is also a continuation-in-part of U.S. patent application Ser. No. 12/644,343 titled “INTEGRATED TESTING PLATFORM FOR CONTACT CENTRES”, filed on Dec. 22, 2009, now issued as U.S. Pat. No. 8,625,772 on Jan. 7, 2014, and is also a continuation-in-part of U.S. patent application Ser. No. 13/567,089 titled “SYSTEM AND METHOD FOR AUTOMATED ADAPTATION AND IMPROVEMENT OF SPEAKER AUTHENTICATION IN A VOICE BIOMETRIC SYSTEM ENVIRONMENT”, filed on Aug. 6, 2012, and is also a continuation-in-part of U.S. patent application Ser. No. 14/140,449 titled “SYSTEM AND METHOD FOR AUTOMATED CHAT TESTING”, filed on Dec. 24, 2013, now issued as U.S. Pat. No. 9,137,183 on Sep. 15, 2015, which is a continuation of U.S. patent application Ser. No. 13/936,147 titled “SYSTEM AND METHOD FOR AUTOMATED CHAT TESTING”, filed on Jul. 6, 2013, the entire specifications of each of which are incorporated herein by reference in their entirety.
[0002] This application is a continuation-in-part of U.S. application Ser. No. 15/613,168 titled “SYSTEM AND METHOD FOR AUTOMATED CONTACT CENTER AGENT WORKSTATION TESTING”, filed on Jun. 3, 2017, which is a continuation-in-part of U.S. application Ser. No. 15/491,965, titled “SYSTEM AND METHOD FOR AUTOMATED THIN CLIENT CONTACT CENTER AGENT DESKTOP TESTING” and filed on Apr. 19, 2017, which is a continuation-in-part of U.S. patent application Ser. No. 15/157,384 titled “SYSTEM AND METHOD FOR AUTOMATED VOICE QUALITY TESTING”, filed on May 17, 2016, which is a continuation of U.S. patent application Ser. No. 14/709,252 titled “SYSTEM AND METHOD FOR AUTOMATED VOICE QUALITY TESTING”, filed on May 11, 2015, now issued as U.S. Pat. No. 9,344,556 on May 17, 2016, which is a continuation of U.S. patent application Ser. No. 14/140,470 titled “SYSTEM AND METHOD FOR AUTOMATED VOICE QUALITY TESTING”, filed on Dec. 25, 2013, now issued as U.S. Pat. No. 9,031,221 on May 12, 2015, which is a continuation of U.S. patent application Ser. No. 13/936,183 titled “SYSTEM AND METHOD FOR AUTOMATED VOICE QUALITY TESTING”, filed on Jul. 6, 2013, which is a continuation-in-part of U.S. patent application Ser. No. 12/644,343 titled “INTEGRATED TESTING PLATFORM FOR CONTACT CENTRES”, filed on Dec. 22, 2009, the entire specifications of each of which are incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
Field of the Invention
[0003] The disclosure relates to the field of system testing, and more particularly to the field of automated quality assurance testing of contact center customer mobile device function when used as part of a contact center's overall solution of both hardware and software components which may include mobile devices from multiple vendors running multiple operating systems.
Discussion of the State of the Art
[0004] FIG. 1 (PRIOR ART) is a typical system architecture diagram of a contact center 100 known to the art. A contact center is similar to a call center, but a contact center has more features. While a call center may communicate mainly by voice, a contact center may communicate via email; text chat, such as, but not limited to, instant messaging, social media posts, and SMS interaction; and web interfaces in addition to voice communication in order to facilitate communications between a customer endpoint 110 and a resource endpoint 120 . Resource 120 may include, but is not limited to, agents, sales representatives, service representatives, or collection agents handling communications with customers 110 on behalf of an enterprise. Resources 120 may be in-house within contact center 100 , or may be remote, such as out-sourcing to a third party, or agents working from home. Contact center 100 may be independently operated or networked with additional centers, and may often be linked to a corporate computer network.
[0005] Contact center 100 may further comprise network interface 130 , text channels 140 , multimedia channels 145 , and contact center components 150 . Text channels 140 may be communications conducted mainly through text, and may comprise social media 141 , email 142 , short message service (SMS) 143 , or instant messaging (IM) 144 , and would communicate through their counterparts within contact center components 150 , each respectively being social server 159 , email server 157 , SMS server 160 , and IM server 158 .
[0006] Multimedia channels 145 may be communications conducted through a variety of mediums, and may comprise a media server 146 , private branch exchange (PBX) 147 , interactive voice response (IVR) 148 , and bots 149 . Text channels 140 and multimedia channels 145 may act as third parties to engage with outside social media services and so a social server 159 may be required to interact with the third party social media 141 . Multimedia channels 145 , are typically present in an enterprise's datacenter; but could be hosted in a remote facility, in a cloud facility, or in a multifunction service facility.
[0007] Contact center components 150 may comprise a routing server 151 , a session initiation protocol (SIP) server 152 , an outbound server 153 , a computer telephony integration (CTI) server 154 , a state and statistics (STAT) server 155 , an automated call distribution facility (ACD) 156 , an email server 157 , an IM server 158 , a social server 159 , a SMS server 160 , a routing database 170 , a historical database 172 , and a campaign database 171 . It is possible that other servers and databases may exist within a contact center, but in this example the referenced components are used. Contact center components 150 , including servers, databases, and other key modules that may be present in a typical contact center may work in a black box environment, may be used collectively in one location, or may be spread over a plurality of locations. Contact center components 150 may even be cloud-based, and more than one of each component shown may be present in a single location.
[0008] Customers 110 may communicate by use of any known form of communication known in the art, be it by a telephone 111 , a mobile smartphone 112 , a tablet 113 , a laptop 114 , or a desktop computer 115 , to name a few examples. Similarly, resources 120 may communicate by use of any known form of communication known in the art, be it by a telephone 121 , a mobile smartphone 122 , a tablet 123 , a laptop 124 , or a desktop computer 125 , to name a few examples. Communication may be conducted through a network interface 130 by way of at least one channel, such as a text channel 140 or a multimedia channel 145 , which communicates with a plurality of contact center components 150 . Available network interfaces 130 may include, but is not limited to, a public switched telephone networks (PSTN) 131 , an internet network 132 , a wide area network (WAN) 133 , or a local area network (LAN) 134 .
[0009] To provide a few example cases, a customer calling on telephone handset 111 may connect through PSTN 131 and terminate on PBX 147 ; a video call originating from tablet 123 may connect through internet connection 132 and terminate on media server 146 ; or a customer device such as smartphone 112 may connect via WAN 133 , and terminate on IVR 148 , such as in the case of a customer calling a customer support line for a bank or a utility service. In another example, an email server 157 would be owned by the contact center 100 and would be used to communicate with a third-party email channel 142 . The number of communication possibilities are vast between the number of possible devices of resources 120 , devices of customers 110 , networks 130 , text channels 140 , multimedia channels 145 , and contact center components 150 , hence the system diagram on FIG. 1 indicates connections between delineated groups rather than individual connections for clarity.
[0010] Continuing from the examples given above, in some conditions where a single medium (such as ordinary telephone calls) is used for interactions that require routing, media server 146 may be more specifically PBX 147 , ACD 156 , or similar media-specific switching system. Generally, when interactions arrive at media server 146 , a route request, or a variation of a route request (for example, a SIP invite message), is sent to SIP server 152 or to an equivalent system such as CTI server 154 . A route request may be a data message sent from a media-handling device, such as media server 146 , to a signaling system, such as SIP server 152 . The message may comprise a request for one or more target destinations to which to send (or route, or deliver) the specific interaction with regard to which the route request was sent. SIP server 152 or its equivalent may, in some cases, carry out any required routing logic itself, or it may forward the route request message to routing server 151 . Routing server 151 executes, using statistical data from STAT server 155 and, optionally, data from routing database 170 , a routing script in response to the route request message and sends a response to media server 146 directing it to route the interaction to a specific target in resources 120 .
[0011] In another case, routing server 151 uses historical information from historical database 172 , or real-time information from campaign database 171 , or both, as well as configuration information (generally available from a distributed configuration system, not shown for convenience) and information from routing database 170 . STAT server 154 receives event notifications from media server 146 , SIP server 152 , or both regarding events pertaining to a plurality of specific interactions handled by media server 146 , SIP server 152 , or both, and STAT server 155 computes one or more statistics for use in routing based on the received event notifications. Routing database 170 may comprise multiple distinct databases, either stored in one database management system or in separate database management systems. Examples of data that may normally be found in routing database 170 may include, but are not limited to: customer relationship management (CRM) data; data pertaining to one or more social networks, including, but not limited to network graphs capturing social relationships within relevant social networks, or media updates made by members of relevant social networks; skills data pertaining to a members of resources 120 , which may be human agents, automated software agents, interactive voice response scripts, and so forth; data extracted from third party data sources including cloud-based data sources such as CRM and other data from SALESFORCE.COM™, credit data from EXPERIAN™, consumer data from DATA.COM™; or any other data that may be useful in making routing decisions. It will be appreciated by one having ordinary skill in the art that there are many means of data integration known in the art, any of which may be used to obtain data from premise-based, single machine-based, cloud-based, public or private data sources as needed, without departing from the scope of the invention. Using information obtained from one or more of STAT server 155 , routing database 170 , campaign database 172 , historical database 171 , and any associated configuration systems, routing server 151 selects a routing target from among a plurality of available resource devices 120 , and routing server 151 then instructs SIP server 152 to route the interaction in question to the selected resource 120 , and SIP server 152 in turn directs media server 146 to establish an appropriate connection between customer 110 and target resource 120 . In this case, the routing script comprises at least the steps of generating a list of all possible routing targets for the interaction regardless of the real-time state of the routing targets using at least an interaction identifier and a plurality of data elements pertaining to the interaction, removing a subset of routing targets from the generated list based on the subset of routing targets being logged out to obtain a modified list, computing a plurality of fitness parameters for each routing target in the modified list, sorting the modified list based on one or more of the fitness parameters using a sorting rule to obtain a sorted target list, and using a target selection rule to consider a plurality of routing targets starting at the beginning of the sorted target list until a routing target is selected. It should be noted that customers 110 are generally, but not necessarily, associated with human customers or users. Nevertheless, it should be understood that routing of other work or interaction types is possible, although in any case, is limited to act or change without input from a management team.
[0012] As contact center software solutions from a number of vendors which together perform all needed tasks, whether as a single monolithic service or a set of multiple service offerings, have become more complex, so have the systems and techniques needed to monitor and test them. The ability to qualify new software versions and variants on the entire range of hardware types expected to be deployed, to qualify new hardware or software combinations as they arise, or to monitor functional efficiency under conditions mimicking actual live usage has become much more important. These types of test software currently exists, and may run on either dedicated equipment, or on live equipment under instances of low live traffic. However, the current solutions may be inflexible in deployment; requiring significant preplanning and hardware resources; lack the ability to test function of important emerging system configurations, such as those that include mobile devices as endpoints of interaction; have little modification capability while running; lack the ability to run unobtrusively and thus cannot be used to diagnose problems encountered during actual call center use; have inflexible result reporting abilities; and require a significant amount of programming knowledge to administer.
[0013] What is needed are computer service package testing suites that are easy and flexible to deploy, that accept modifications without the use of complex procedures while running, that have highly configurable and easily specified reporting formats, that can be deployed through a centralized gateway using simplified runtime commands instead of programming changes to the suites' source code themselves and that can be used to test a wide range of both software and hardware combinations in use, including mobile devices.
SUMMARY OF THE INVENTION
[0014] Accordingly, the inventor has conceived and reduced to practice, a system and method for automated contact center customer mobile device client infrastructure testing which has a single interface, does not need significant programming ability to operate, automates many types of testing and allocates resources and pre-loads test payloads.
[0015] According to a preferred embodiment of the invention, a system and method for conducting centrally controlled, robust and easily customized contact center customer mobile device client tests has been created. This centralized test suite may execute tests for voice and chat interaction software, and other general functions (such as performing transactional operations that are utilized to set the context of a customer's subsequent interactions both via mobile and not) in conjunction with any support software frequently used by the contact center. Customer mobile devices with differing CPU, RAM, operating system vendor, versions and patch levels, voice or chat management software versions or vendors as well as third party software payloads may be easily tested concurrently with results categorized and information depth dictated by the test analysts. Test setup is accomplished using a robust set of simple test directive commands and modifiers which insulates the analyst from the underlying programming. Commands and modifiers may be strung together to form macros that represent more complex test case conditions. The embodiment allows for testing to be run on live customer mobile devices without noticeable disruption of actual customer time and also allows testing to be run on specially set aside, otherwise idle customer mobile devices depending on the needs of the test conditions. The suite is such that stopping or modifying a test under execution may be accomplished without catastrophic test disruption, or programming knowledge of test execution.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0016] The accompanying drawings illustrate several embodiments of the invention and, together with the description, serve to explain the principles of the invention according to the embodiments. It will be appreciated by one skilled in the art that the particular embodiments illustrated in the drawings are merely exemplary, and are not to be considered as limiting of the scope of the invention or the claims herein in any way.
[0017] FIG. 1 (PRIOR ART) is a typical system architecture diagram of a contact center including components commonly known in the art.
[0018] FIG. 2 is a block diagram illustrating an exemplary system architecture for an automated contact center test engine including a mobile device test module, according to a preferred embodiment of the invention
[0019] FIG. 3 is a block diagram illustrating an exemplary system architecture for a system and method for automated chat and automated voice testing services on customer mobile devices, according to a preferred embodiment of the invention.
[0020] FIG. 4 is a block diagram illustrating an exemplary system architecture 400 for a system and method for automated general functions testing according to a preferred embodiment of the invention.
[0021] FIG. 5 is a method flow diagram illustrating an exemplary system for certifying mobile devices of different operating systems, hardware configurations and possibly differing software payloads prior to a full scale update of call center voice software, call center chat software, call center customer relationship management system software or when issues in performance are detected with existing software on workstations of different configuration according to a preferred embodiment of the invention.
[0022] FIG. 6 is a block diagram illustrating an exemplary hardware architecture of a computing device used in an embodiment of the invention.
[0023] FIG. 7 is a block diagram illustrating an exemplary logical architecture for a client device, according to an embodiment of the invention.
[0024] FIG. 8 is a block diagram showing an exemplary architectural arrangement of clients, servers, and external services, according to an embodiment of the invention.
[0025] FIG. 9 is another block diagram illustrating an exemplary hardware architecture of a computing device used in various embodiments of the invention.
DETAILED DESCRIPTION
[0026] The inventor has conceived, and reduced to practice, in a preferred embodiment of the invention, a system and method for automated contact center customer client infrastructure testing.
[0027] One or more different aspects may be described in the present application. Further, for one or more of the aspects described herein, numerous alternative arrangements may be described; it should be appreciated that these are presented for illustrative purposes only and are not limiting of the aspects contained herein or the claims presented herein in any way. One or more of the arrangements may be widely applicable to numerous aspects, as may be readily apparent from the disclosure. In general, arrangements are described in sufficient detail to enable those skilled in the art to practice one or more of the aspects, and it should be appreciated that other arrangements may be utilized and that structural, logical, software, electrical and other changes may be made without departing from the scope of the particular aspects. Particular features of one or more of the aspects described herein may be described with reference to one or more particular aspects or figures that form a part of the present disclosure, and in which are shown, by way of illustration, specific arrangements of one or more of the aspects. It should be appreciated, however, that such features are not limited to usage in the one or more particular aspects or figures with reference to which they are described. The present disclosure is neither a literal description of all arrangements of one or more of the aspects nor a listing of features of one or more of the aspects that must be present in all arrangements.
[0028] Headings of sections provided in this patent application and the title of this patent application are for convenience only, and are not to be taken as limiting the disclosure in any way.
[0029] Devices that are in communication with each other need not be in continuous communication with each other, unless expressly specified otherwise. In addition, devices that are in communication with each other may communicate directly or indirectly through one or more communication means or intermediaries, logical or physical.
[0030] A description of an aspect with several components in communication with each other does not imply that all such components are required. To the contrary, a variety of optional components may be described to illustrate a wide variety of possible aspects and in order to more fully illustrate one or more aspects. Similarly, although process steps, method steps, algorithms or the like may be described in a sequential order, such processes, methods and algorithms may generally be configured to work in alternate orders, unless specifically stated to the contrary. In other words, any sequence or order of steps that may be described in this patent application does not, in and of itself, indicate a requirement that the steps be performed in that order. The steps of described processes may be performed in any order practical. Further, some steps may be performed simultaneously despite being described or implied as occurring non-simultaneously (e.g., because one step is described after the other step). Moreover, the illustration of a process by its depiction in a drawing does not imply that the illustrated process is exclusive of other variations and modifications thereto, does not imply that the illustrated process or any of its steps are necessary to one or more of the aspects, and does not imply that the illustrated process is preferred. Also, steps are generally described once per aspect, but this does not mean they must occur once, or that they may only occur once each time a process, method, or algorithm is carried out or executed. Some steps may be omitted in some aspects or some occurrences, or some steps may be executed more than once in a given aspect or occurrence.
[0031] When a single device or article is described herein, it will be readily apparent that more than one device or article may be used in place of a single device or article. Similarly, where more than one device or article is described herein, it will be readily apparent that a single device or article may be used in place of the more than one device or article.
[0032] The functionality or the features of a device may be alternatively embodied by one or more other devices that are not explicitly described as having such functionality or features. Thus, other aspects need not include the device itself.
[0033] Techniques and mechanisms described or referenced herein will sometimes be described in singular form for clarity. However, it should be appreciated that particular aspects may include multiple iterations of a technique or multiple instantiations of a mechanism unless noted otherwise. Process descriptions or blocks in figures should be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps in the process. Alternate implementations are included within the scope of various aspects in which, for example, functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those having ordinary skill in the art.
Conceptual Architecture
[0034] FIG. 2 is a block diagram illustrating an exemplary system architecture 200 for an automated contact center test engine including a mobile device test module, according to a preferred embodiment of the invention. According to the embodiment, system 200 may comprise a standard contact center 100 with the addition of new elements: an automated end-to-end contact center testing system 281 , and a mobile device testing module 285 , both of which may be operating on at least one network 130 , 287 as illustrated.
[0035] As discussed above in FIG. 1 , a plurality of customers 110 and network-connected resources 120 may connect to a contact center 150 via a network 130 using a variety of specific communication means which may include, but not limited to, text-based communication channels 140 , such as social media networks 141 , email 142 , SMS 143 , instant messaging 144 ; or via multimedia communication channels 145 , such as through media server 146 , PBX 147 , IVR system 148 , or via communication bots 149 that may automate or simulate communication (as may be used for testing purposes without relying on actual customer communication). Communication may occur over a variety of network interfaces 130 , such as, but not limited to, PSTN 131 , the Internet 132 , WAN 133 , or LAN 134 according to various arrangements. For example, internal testing may occur exclusively within a LAN, whereas testing of online helpdesk interactions may use Internet-connected IM, email, or other arrangements to provide practical metrics pertaining to bandwidth, server load, and the like.
[0036] A contact center may comprise a number of systems and features common in the art, such as, for example, a routing server 151 that directs other components based on routing instructions from a routing database 170 to route interactions to appropriate handling endpoints (such as agents to answer calls or IMs), a SIP server 152 that handles SIP-based telephony, an outbound server 153 that processes outbound interaction attempts such as customer callbacks, STAT server 155 that manages internal contact center state monitoring and statistics (for example, tracking interaction metrics such as handle time, queue wait time, number of interactions handled or transferred, and other various metrics that are commonly tracked in contact center operations), or an automated call distributor (ACD) that may be used to automatically distribute interactions to endpoints (for example, based on customer input or agent skills). Additionally, a variety of interaction servers may be used to appropriately receive, process, and handle interactions such as a CTI server 154 that may be used to connect telephony and computer-based or IP technologies, email server 157 that may be used to handle email-based interactions, IM server 158 that may be used to handle web-based instant messaging, social server 159 that may be used to handle content from social media networks (such as communicating directly with a social network's public API, for example to read and process content and user messages), or SMS server 160 that may be used to handle SMS-based text messages. Additionally, contact center campaign information (for example, metric goals pertaining to a particular customer or campaign) may be stored in campaign database 171 for reference, and historical interaction information may be stored in historical database 172 , such as to store call recording for later reference or analysis.
[0037] FIG. 3 is a block diagram illustrating an exemplary system architecture 300 for a system and method for automated chat and automated voice testing services on customer mobile devices, according to a preferred embodiment of the invention. End-to-end contact center testing systems 281 are invariably quite complex and may greatly benefit from a deployment system that allows scheduling, initiation, specification, management, and allocation of resources for a wide range of analyses without the need for extensive programming knowledge on the part of the analyst.
[0038] A system for automated chat testing 310 may incorporate common contact center elements, including customer mobile devices such as smartphones 393 a to 393 n , and tablets 392 a to 392 n , each running one or more command center package clients and support software employed by the customer contact center. Testing of these mobile devices may require that a set of varied mobile devices with regard to type, underlying operating system and individual software payload be seamlessly tested, and the results, which may be different in format due to operating system differences, normalized for meaningful presentation with data from other sources. These control and normalization capabilities may require the presence of a dedicated mobile device testing module 285 . For contact center testing engine 281 to be most predictive to performance under operation, it may run in parallel to actual contact center operations. As illustrated, chat testing system 310 may implement a test case management (TCM) platform 311 , which may serve as the beginning or origin of a test case. TCM platform 311 may operate autonomously using preprogrammed standard tests tailored to a specific customer, or optionally may accept human interaction from a test system control portal 350 . In some cases, a local test control terminal 351 may be used. Local test control terminal 351 may provide a graphical user interface for manipulation of test cases using runtime commands and parameters rather than through modification of test function code, and may also provide a means for accessing an output module 352 to allow viewing of both interim and final test result reports on a text-based output terminal. These results and test related code may also be permanently stored in a testing database 312 . Other embodiments may employ a networked test deployment terminal and output module (not shown) which may connect from a distance using a network connection 395 , such as a virtual private network or similar secure long-distance connection familiar to those skilled in the art. When a test is run, TCM platform 311 initiates a test case with chat cruncher 313 and contact center manager (CCM) platform 314 , which may each then begin their respective automated testing processes. In embodiments that are configured to exercise contact center customer mobile devices 392 a to 392 n , 393 a to 393 n , chat cruncher 313 may simulate a plurality of virtual customers 320 , which may operate via a web server 319 , to send and receive data from the mobile devices through one or more mobile device control modules 362 and associated mobile device response log data store 363 . CCM platform 314 may similarly simulate virtual contact center agents 315 which may receive and respond to data requests on each of a plurality of mobile devices which may have differing physical specifications and third-party software loads. Data requests sent by simulated customers 320 through the mobile device control module 362 and then to a mobile device automation module 394 a - n operating on a mobile device 392 a - n , 393 a - n . Commands may come through a wireless network (which may include a WiFi connection or network of device's cellular provider 391 ), or a direct physical data connection (such as a universal serial bus or USB memory device). Any mobile device specific commands may originate from a mobile device command data store 361 . Mobile device commands may be commands that may be required to prepare and support each mobile device undergoing testing, including, but not limited to, the ability of the CCM simulated agents to issue and retrieve responses, and case management text to each mobile device as required by test module parameters provided by mobile device control module 362 . A mobile device automation module 394 a - n may then execute commands on the processor of the mobile device, interacting as needed with other device hardware or software to perform the command tasks, for example to initiate a voice call (which may be a telephony call or a VoIP call using a packet data network) using click-to-dial, and optionally pre-authenticating the customer by retrieving and providing any needed credentials (such as an access code or account number to be provided to an IVR system that is being dialed). Responses, both those from simulated agents and from possible data flow metrics and mobile device status information, may follow the reverse transmission pathway from the mobile device through the wireless network to the mobile device control module 362 , where that information may then be forwarded to a test data store 312 or mobile device response log data store 363 , depending on the nature of the data and test specific parameters. Using the described test architecture, it will be appreciated that the flow of data requests within a test case is bidirectional. For example, requests may continually and asynchronously be sent from simulated customers 320 to simulated agents 315 and vice-versa, without necessitating a strict pattern or rhythm of data flow. It will also be appreciated that in such a manner, it is possible to simulate a customer sending multiple chat requests (or other text- or voice-based requests) while an agent waits to send a response, or for an agent to send multiple requests while a customer waits. Such occurrences are commonplace in practice, and in this manner a test case may more accurately simulate actual contact center operations for more relevant and reliable testing data.
[0039] Contact center voice interaction with customers may place significantly more load on the customer's mobile devices 392 a - n , 393 a - na ; on the wireless network(s) on which the mobile device operates, as voice may require a wider bandwidth to present; and there may be speech-to-text transcription functions to perform at some point within the contact center system. There may also be some pressure to provide a faster response during voice interaction which may lead to increased concurrent use of a wide range of software resources in a voice interaction environment. A system for automated voice call testing 370 may incorporate common contact center elements and running in parallel to actual contact center operations. As illustrated, and similar to chat testing system 310 , call testing system 370 may also have its own TCM platform 371 that may serve as the beginning or origin of a test case. TCM platform 371 may also operate autonomously, or, optionally, may accept human interaction at a test system control portal 350 via test terminal 351 for manipulation of test cases, and viewing of both interim and final test result reports with output module 352 . Test results may be stored in a testing database 372 . When a test is run, TCM platform 371 initiates a test case with call generator 373 and CCM platform 374 , which may each begin their respective automated testing processes. Call flow generator 373 may simulate a plurality of virtual customers 380 , which operate via a web server 379 , and may send voice data requests pre-stored in a call flow testing data store 381 . In this embodiment, all outbound and inbound voice data is transmitted through a mobile device control module 362 to the wireless network interface 391 , which may be the contact center's wireless network, such as WiFi, or the mobile device's service provider's network. CCM platform 374 may similarly simulate virtual contact center agents 375 , which may receive and respond to voice data requests by exercising various features of the contact center's customer relationship management software (CRM) mobile device client app in response to the test parameters possibly as supported by a mobile device command data store 361 operating as part of the function of mobile device control module 362 . Data requests sent by simulated customers 380 arriving at the mobile device control module 362 may be forwarded to a receiving mobile device under test 392 b and requests from agents 392 b to customers also via a mobile device control module 362 . Virtual agents 375 may operate by interacting with the mobile device control module 362 according to the specific nature of a test case. During and/or after the execution of a test case, data may be stored in data store 372 by CCM platform 374 or call generator 373 , for the formulation of test reports to be stored for later viewing by a user via TCM platform 371 . In this manner, it will be appreciated that the flow of data requests within a test case is bidirectional, i.e. requests may continually and asynchronously be sent from simulated customers 380 to simulated agents 375 and vice-versa, without necessitating a strict pattern or rhythm of data flow. It will be appreciated that in such a manner it is possible to simulate a customer uttering multiple voice requests, requiring further CRM interaction while an agent attempts to fulfill a prior task, or for an agent to have to wait while a customer produces needed data. Such occurrences are commonplace in practice, and in this manner a test case may more accurately simulate actual contact center operations for more relevant and reliable testing data.
[0040] Besides testing chat and voice services, a business may want to conduct generalized testing of their mobile website or mobile apps, to monitor and test various non-interaction usage that may provide additional information pertaining to a customer “journey” as they interact with various software and systems. For example, if a customer performs a balance transfer via a banking app and then uses a click-to-dial button to call for assistance, the balance transfer may provide additional insight into the reason for the call, and this information may be used to expedite IVR interaction or to bring a contact center agent up to speed on the customer's situation. This scenario may be simulated during testing to (for example) ensure that the proper information is being collected and sent to the correct endpoints (IVR, real or virtual agents, etc.) so that the customer journey is handled efficiently. To provide this function, automated contact system test engine may be configured to conduct more generalized testing. FIG. 4 is a block diagram illustrating an exemplary system architecture 400 for a system and method for automated general functions testing according to a preferred embodiment of the invention. General testing system 400 may be identical to chat and voice testing system 300 with components and functions, such as, a network connection 395 , a testing system control module 350 , a test deployment terminal 351 , an output module 352 , a mobile device command data store 361 , a mobile device control module 362 , a mobile device response log data store 363 , a wireless network 391 , and mobile devices 392 [ a - n ] and 393 [ a - n ]. Functions discussed above such as the ability to modify tests during runtime, and creation or modification of tests without extensive programming knowledge, to name a few, are also available. The difference is the automated testing system; whereas testing system 300 features an automated voice testing system 370 , and automated chat testing system 310 , for testing voice systems and chat systems, respectively, general testing system 410 may test general functions of a mobile website or a mobile app. Automated general testing system 410 , itself, may have many features that may be found in automated voice testing system 370 , and automated chat testing system 310 , such as, a TCM platform 411 for starting and running tests, test data store 412 for storing of test results and test code, a CCM platform 414 for running of simulated agents 415 , and a web server 419 for running of simulated customers 420 . The unique feature of general testing system 410 is an action simulator 413 . Action simulator 413 may be configured by a tester to designate emulate actions that a user or agent may issue when browsing a mobile website, or using a mobile app using a wide variety of mobile device configurations. These actions may include, but is not limited to, logging-in to a system, accessing or exiting a mobile site or mobile app, navigating a website or app, accessing data stored on system databases, using unique functions provided by the website or app, activating and conducting simulated customer-agent interactions, and the like. Testing may be conducted in conjunction and in parallel with live systems without disruption of running services, or conducted in isolation on a test system. Additionally, general testing system 410 may spawn a large number of simulated agents, and simulated customers to test the mobile website or mobile app under stressed conditions. This may provide the business with valuable insight into any problematic parts and failure points before deploying new software or new versions to the public.
[0041] Centralized deployment of all test set-up, initiation and status review is afforded by logically connecting the test system portal 350 and user interface 351 to the TCM Platforms 311 , 371 , 471 of the test system. Remote review of test status, as well as review of test results, is also afforded by network connection 395 of test system portal 350 .
[0042] It should be understood that although automated chat test system 310 , automated voice test system 370 , and automated general test system 410 are illustrated in separate systems, this is not meant to indicate any type of limitation of the invention. These features, amongst others, may be featured on a single system, or a plurality of systems depending on the requirements of the user.
DETAILED DESCRIPTION OF EXEMPLARY ASPECTS
[0043] FIG. 5 is a flow diagram illustrating an exemplary method 500 for certifying mobile devices of different operating systems, hardware configurations, and software payloads prior to a full-scale update of call center voice software, call center chat software, call center customer relationship management system software; or when issues in performance are detected with existing software on workstations of different configuration according to a preferred embodiment. Testing of each mobile device and mobile device clients begins when the embodiment connects to the mobile device at step 501 . This may be through a contact center's wireless network such, as a WiFi network or over mobile device's service provider's network. At step 502 , once a stable bidirectional logical connection has been established, connection metrics are recorded. Connection metrics may include, but would not be limited only to, connection set-up time, connection signal strength, mobile device location (as determined by GPS or LAN/WAN station triangulation), and applications running on the mobile device among other items known to those skilled in the art. At step 503 , contact center clients and support apps may then be opened if not already running. While this function is only listed once in the flow diagram for simplicity, applications may be remotely opened as needed to fulfill the specifications of a running mobile device operation test at any point during testing. At step 504 , the metrics of starting the standard contact center apps on each mobile device, which may include but are not limited to time from app initiation to ready for input, CPU usage during launch and at ready for input, and active memory usage among other factors known to those skilled in the art will be monitored and recorded. At step 505 , the software modules for generating and implementing varying simulated chat communication tests, chat testing module 310 described in FIG. 3 , along with other possible processes specified by test parameters, may then be used to fully exercise contact center chat support applications. At step 506 , chat operational metrics for the tested mobile device will then be recorded for later review. At step 507 , a similar exercise of voice call support apps on mobile device may then be undertaken in manners analogous to simulated chat testing in step 505 with call testing module 370 . At step 508 , metrics of interest from the simulated call testing may be recorded for later review. At step 509 , other mobile device resident applications that may affect contact center app operation either by a direct yet unforeseen interaction with those contact center apps or through factors such as but not limited to CPU usage, and running memory usage may be undertaken per specific preprogrammed test parameters with general test module 410 . At step 510 , the pre-designated results of such preprogrammed supplemental testing may also be recorded for later review.
[0044] It should be noted that although method 500 illustrates a comprehensive test of chat, call, and general functions, the various tests may be conducted in any order, and particular tests may be picked and executed according to user requirements. For example, if a business only requires testing of the chat functions of a mobile website or mobile app, only the chat function may be conducted, and voice and general functions testing may be omitted.
Hardware Architecture
[0045] Generally, the techniques disclosed herein may be implemented on hardware or a combination of software and hardware. For example, they may be implemented in an operating system kernel, in a separate user process, in a library package bound into network applications, on a specially constructed machine, on an application-specific integrated circuit (ASIC), or on a network interface card.
[0046] Software/hardware hybrid implementations of at least some of the aspects disclosed herein may be implemented on a programmable network-resident machine (which should be understood to include intermittently connected network-aware machines) selectively activated or reconfigured by a computer program stored in memory. Such network devices may have multiple network interfaces that may be configured or designed to utilize different types of network communication protocols. A general architecture for some of these machines may be described herein in order to illustrate one or more exemplary means by which a given unit of functionality may be implemented. According to specific aspects, at least some of the features or functionalities of the various aspects disclosed herein may be implemented on one or more general-purpose computers associated with one or more networks, such as for example an end-user computer system, a client computer, a network server or other server system, a mobile computing device (e.g., tablet computing device, mobile phone, smartphone, laptop, or other appropriate computing device), a consumer electronic device, a music player, or any other suitable electronic device, router, switch, or other suitable device, or any combination thereof. In at least some aspects, at least some of the features or functionalities of the various aspects disclosed herein may be implemented in one or more virtualized computing environments (e.g., network computing clouds, virtual machines hosted on one or more physical computing machines, or other appropriate virtual environments).
[0047] Referring now to FIG. 6 , there is shown a block diagram depicting an exemplary computing device 10 suitable for implementing at least a portion of the features or functionalities disclosed herein. Computing device 10 may be, for example, any one of the computing machines listed in the previous paragraph, or indeed any other electronic device capable of executing software- or hardware-based instructions according to one or more programs stored in memory. Computing device 10 may be configured to communicate with a plurality of other computing devices, such as clients or servers, over communications networks such as a wide area network a metropolitan area network, a local area network, a wireless network, the Internet, or any other network, using known protocols for such communication, whether wireless or wired.
[0048] In one aspect, computing device 10 includes one or more central processing units (CPU) 12 , one or more interfaces 15 , and one or more busses 14 (such as a peripheral component interconnect (PCI) bus). When acting under the control of appropriate software or firmware, CPU 12 may be responsible for implementing specific functions associated with the functions of a specifically configured computing device or machine. For example, in at least one aspect, a computing device 10 may be configured or designed to function as a server system utilizing CPU 12 , local memory 11 and/or remote memory 16 , and interface(s) 15 . In at least one aspect, CPU 12 may be caused to perform one or more of the different types of functions and/or operations under the control of software modules or components, which for example, may include an operating system and any appropriate applications software, drivers, and the like.
[0049] CPU 12 may include one or more processors 13 such as, for example, a processor from one of the Intel, ARM, Qualcomm, and AMD families of microprocessors. In some aspects, processors 13 may include specially designed hardware such as application-specific integrated circuits (ASICs), electrically erasable programmable read-only memories (EEPROMs), field-programmable gate arrays (FPGAs), and so forth, for controlling operations of computing device 10 . In a particular aspect, a local memory 11 (such as non-volatile random access memory (RAM) and/or read-only memory (ROM), including for example one or more levels of cached memory) may also form part of CPU 12 . However, there are many different ways in which memory may be coupled to system 10 . Memory 11 may be used for a variety of purposes such as, for example, caching and/or storing data, programming instructions, and the like. It should be further appreciated that CPU 12 may be one of a variety of system-on-a-chip (SOC) type hardware that may include additional hardware such as memory or graphics processing chips, such as a QUALCOMM SNAPDRAGON™ or SAMSUNG EXYNOS™ CPU as are becoming increasingly common in the art, such as for use in mobile devices or integrated devices.
[0050] As used herein, the term “processor” is not limited merely to those integrated circuits referred to in the art as a processor, a mobile processor, or a microprocessor, but broadly refers to a microcontroller, a microcomputer, a programmable logic controller, an application-specific integrated circuit, and any other programmable circuit.
[0051] In one aspect, interfaces 15 are provided as network interface cards (NICs). Generally, NICs control the sending and receiving of data packets over a computer network; other types of interfaces 15 may for example support other peripherals used with computing device 10 . Among the interfaces that may be provided are Ethernet interfaces, frame relay interfaces, cable interfaces, DSL interfaces, token ring interfaces, graphics interfaces, and the like. In addition, various types of interfaces may be provided such as, for example, universal serial bus (USB), Serial, Ethernet, FIREWIRE™, THUNDERBOLT™, PCI, parallel, radio frequency (RF), BLUETOOTH™, near-field communications (e.g., using near-field magnetics), 802.11 (WiFi), frame relay, TCP/IP, ISDN, fast Ethernet interfaces, Gigabit Ethernet interfaces, Serial ATA (SATA) or external SATA (ESATA) interfaces, high-definition multimedia interface (HDMI), digital visual interface (DVI), analog or digital audio interfaces, asynchronous transfer mode (ATM) interfaces, high-speed serial interface (HSSI) interfaces, Point of Sale (POS) interfaces, fiber data distributed interfaces (FDDIs), and the like. Generally, such interfaces 15 may include physical ports appropriate for communication with appropriate media. In some cases, they may also include an independent processor (such as a dedicated audio or video processor, as is common in the art for high-fidelity AN hardware interfaces) and, in some instances, volatile and/or non-volatile memory (e.g., RAM).
[0052] Although the system shown in FIG. 6 illustrates one specific architecture for a computing device 10 for implementing one or more of the aspects described herein, it is by no means the only device architecture on which at least a portion of the features and techniques described herein may be implemented. For example, architectures having one or any number of processors 13 may be used, and such processors 13 may be present in a single device or distributed among any number of devices. In one aspect, a single processor 13 handles communications as well as routing computations, while in other aspects a separate dedicated communications processor may be provided. In various aspects, different types of features or functionalities may be implemented in a system according to the aspect that includes a client device (such as a tablet device or smartphone running client software) and server systems (such as a server system described in more detail below).
[0053] Regardless of network device configuration, the system of an aspect may employ one or more memories or memory modules (such as, for example, remote memory block 16 and local memory 11 ) configured to store data, program instructions for the general-purpose network operations, or other information relating to the functionality of the aspects described herein (or any combinations of the above). Program instructions may control execution of or comprise an operating system and/or one or more applications, for example. Memory 16 or memories 11 , 16 may also be configured to store data structures, configuration data, encryption data, historical system operations information, or any other specific or generic non-program information described herein.
[0054] Because such information and program instructions may be employed to implement one or more systems or methods described herein, at least some network device aspects may include nontransitory machine-readable storage media, which, for example, may be configured or designed to store program instructions, state information, and the like for performing various operations described herein. Examples of such nontransitory machine-readable storage media include, but are not limited to, magnetic media such as hard disks, floppy disks, and magnetic tape; optical media such as CD-ROM disks; magneto-optical media such as optical disks, and hardware devices that are specially configured to store and perform program instructions, such as read-only memory devices (ROM), flash memory (as is common in mobile devices and integrated systems), solid state drives (SSD) and “hybrid SSD” storage drives that may combine physical components of solid state and hard disk drives in a single hardware device (as are becoming increasingly common in the art with regard to personal computers), memristor memory, random access memory (RAM), and the like. It should be appreciated that such storage means may be integral and non-removable (such as RAM hardware modules that may be soldered onto a motherboard or otherwise integrated into an electronic device), or they may be removable such as swappable flash memory modules (such as “thumb drives” or other removable media designed for rapidly exchanging physical storage devices), “hot-swappable” hard disk drives or solid state drives, removable optical storage discs, or other such removable media, and that such integral and removable storage media may be utilized interchangeably. Examples of program instructions include both object code, such as may be produced by a compiler, machine code, such as may be produced by an assembler or a linker, byte code, such as may be generated by for example a JAVA™ compiler and may be executed using a Java virtual machine or equivalent, or files containing higher level code that may be executed by the computer using an interpreter (for example, scripts written in Python, Perl, Ruby, Groovy, or any other scripting language).
[0055] In some aspects, systems may be implemented on a standalone computing system. Referring now to FIG. 7 , there is shown a block diagram depicting a typical exemplary architecture of one or more aspects or components thereof on a standalone computing system. Computing device 20 includes processors 21 that may run software that carry out one or more functions or applications of aspects, such as for example a client application 24 . Processors 21 may carry out computing instructions under control of an operating system 22 such as, for example, a version of MICROSOFT WINDOWS™ operating system, APPLE macOS™ or iOS™ operating systems, some variety of the Linux operating system, ANDROID™ operating system, or the like. In many cases, one or more shared services 23 may be operable in system 20 , and may be useful for providing common services to client applications 24 . Services 23 may for example be WINDOWS™ services, user-space common services in a Linux environment, or any other type of common service architecture used with operating system 21 . Input devices 28 may be of any type suitable for receiving user input, including for example a keyboard, touchscreen, microphone (for example, for voice input), mouse, touchpad, trackball, or any combination thereof. Output devices 27 may be of any type suitable for providing output to one or more users, whether remote or local to system 20 , and may include for example one or more screens for visual output, speakers, printers, or any combination thereof. Memory 25 may be random-access memory having any structure and architecture known in the art, for use by processors 21 , for example to run software. Storage devices 26 may be any magnetic, optical, mechanical, memristor, or electrical storage device for storage of data in digital form (such as those described above, referring to FIG. 6 ). Examples of storage devices 26 include flash memory, magnetic hard drive, CD-ROM, and/or the like.
[0056] In some aspects, systems may be implemented on a distributed computing network, such as one having any number of clients and/or servers. Referring now to FIG. 8 , there is shown a block diagram depicting an exemplary architecture 30 for implementing at least a portion of a system according to one aspect on a distributed computing network. According to the aspect, any number of clients 33 may be provided. Each client 33 may run software for implementing client-side portions of a system; clients may comprise a system 20 such as that illustrated in FIG. 7 . In addition, any number of servers 32 may be provided for handling requests received from one or more clients 33 . Clients 33 and servers 32 may communicate with one another via one or more electronic networks 31 , which may be in various aspects any of the Internet, a wide area network, a mobile telephony network (such as CDMA or GSM cellular networks), a wireless network (such as WiFi, WiMAX, LTE, and so forth), or a local area network (or indeed any network topology known in the art; the aspect does not prefer any one network topology over any other). Networks 31 may be implemented using any known network protocols, including for example wired and/or wireless protocols.
[0057] In addition, in some aspects, servers 32 may call external services 37 when needed to obtain additional information, or to refer to additional data concerning a particular call. Communications with external services 37 may take place, for example, via one or more networks 31 . In various aspects, external services 37 may comprise web-enabled services or functionality related to or installed on the hardware device itself. For example, in one aspect where client applications 24 are implemented on a smartphone or other electronic device, client applications 24 may obtain information stored in a server system 32 in the cloud or on an external service 37 deployed on one or more of a particular enterprise's or user's premises.
[0058] In some aspects, clients 33 or servers 32 (or both) may make use of one or more specialized services or appliances that may be deployed locally or remotely across one or more networks 31 . For example, one or more databases 34 may be used or referred to by one or more aspects. It should be understood by one having ordinary skill in the art that databases 34 may be arranged in a wide variety of architectures and using a wide variety of data access and manipulation means. For example, in various aspects one or more databases 34 may comprise a relational database system using a structured query language (SQL), while others may comprise an alternative data storage technology such as those referred to in the art as “NoSQL” (for example, HADOOP CASSANDRA™, GOOGLE BIGTABLE™, and so forth). In some aspects, variant database architectures such as column-oriented databases, in-memory databases, clustered databases, distributed databases, or even flat file data repositories may be used according to the aspect. It will be appreciated by one having ordinary skill in the art that any combination of known or future database technologies may be used as appropriate, unless a specific database technology or a specific arrangement of components is specified for a particular aspect described herein. Moreover, it should be appreciated that the term “database” as used herein may refer to a physical database machine, a cluster of machines acting as a single database system, or a logical database within an overall database management system. Unless a specific meaning is specified for a given use of the term “database”, it should be construed to mean any of these senses of the word, all of which are understood as a plain meaning of the term “database” by those having ordinary skill in the art.
[0059] Similarly, some aspects may make use of one or more security systems 36 and configuration systems 35 . Security and configuration management are common information technology (IT) and web functions, and some amount of each are generally associated with any IT or web systems. It should be understood by one having ordinary skill in the art that any configuration or security subsystems known in the art now or in the future may be used in conjunction with aspects without limitation, unless a specific security 36 or configuration system 35 or approach is specifically required by the description of any specific aspect.
[0060] FIG. 9 shows an exemplary overview of a computer system 40 as may be used in any of the various locations throughout the system. It is exemplary of any computer that may execute code to process data. Various modifications and changes may be made to computer system 40 without departing from the broader scope of the system and method disclosed herein. Central processor unit (CPU) 41 is connected to bus 42 , to which bus is also connected memory 43 , nonvolatile memory 44 , display 47 , input/output (I/O) unit 48 , and network interface card (NIC) 53 . I/O unit 48 may, typically, be connected to keyboard 49 , pointing device 50 , hard disk 52 , and real-time clock 51 . NIC 53 connects to network 54 , which may be the Internet or a local network, which local network may or may not have connections to the Internet. Also shown as part of system 40 is power supply unit 45 connected, in this example, to a main alternating current (AC) supply 46 . Not shown are batteries that could be present, and many other devices and modifications that are well known but are not applicable to the specific novel functions of the current system and method disclosed herein. It should be appreciated that some or all components illustrated may be combined, such as in various integrated applications, for example Qualcomm or Samsung system-on-a-chip (SOC) devices, or whenever it may be appropriate to combine multiple capabilities or functions into a single hardware device (for instance, in mobile devices such as smartphones, video game consoles, in-vehicle computer systems such as navigation or multimedia systems in automobiles, or other integrated hardware devices).
[0061] In various aspects, functionality for implementing systems or methods of various aspects may be distributed among any number of client and/or server components. For example, various software modules may be implemented for performing various functions in connection with the system of any particular aspect, and such modules may be variously implemented to run on server and/or client components.
[0062] The skilled person will be aware of a range of possible modifications of the various aspects described above. Accordingly, the present invention is defined by the claims and their equivalents.
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An automated contact center agent mobile device client infrastructure testing system comprising a mobile device command repository is disclosed. The system also has a mobile device control module that retrieves mobile device commands from the repository, receives instructions, data, and parameters for contact center device testing, runs predesignated contact center device test suites on at least one mobile device, receives contact center device test suite result data from mobile devices, and forwards the contact center device test suite result data received from mobile devices to a contact center device test manager system.
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CROSS-REFERENCE AND INCORPORATION BY REFERENCE
This application is a 371 of International Application No. PCT/EP2012/054700, filed on Mar. 16, 2012, which, in turn, claims priority to German Application No. DE 20 2011 100627.5, filed on May 12, 2011, and to German Application No. DE 20 2011 101599.1, filed on May 31, 2011. Each of these applications are incorporated by reference.
This invention relates to an offshore foundation for wind energy installations. Such foundations or supporting structures are used to anchor wind energy installations securely to the seabed.
FIELD OF THE INVENTION
For some time now, wind energy installations have been installed not just onshore, i.e. on land, but also offshore, i.e. at sea, as for example in the offshore wind farms in the North Sea and the Baltic Sea. Offshore wind energy installations are subject to extreme conditions. For example, they are anchored in sea depths of 20 to 60 meters using a foundation. The foundation, which can also be referred to as a supporting structure, is subject to extreme mechanical and chemical loads and sea currents. Different types of offshore to foundations are known, for example monopile, jacket, tripod, tripile or bucket designs. This invention primarily concerns a jacket construction design. This is a latticework made of steel.
SUMMARY OF THE INVENTION
The object of this invention is to present an offshore foundation or supporting structure for wind energy installations, specifically an offshore foundation which can be manufactured, transported, assembled and/or repaired with little effort or expense.
The invention resolves this issue by using an offshore supporting structure with multiple, preferably six, piles which can be anchored in the seabed and are specifically tubular, and a composite latticework structure consisting of many bars, specifically steel tubes, such that the latticework structure can be made of multiple prefabricated latticework segments, where each latticework segment has six corners that can be connected to the corners of another latticework segment.
The steel tubes are preferably attached to the latticework structure using nodes. This type of node preferably connects two or more, specifically at least three, tubes to one another. The latticework segments are designed to be hexagonal, in accordance with the invention. Here, a hexagonal design refers essentially to a cross-section of the latticework segment. The latticework segments will preferably have a hexagonal cross-section relative to a central axis, and will preferably be essentially cylindrical or conical in design. The hexagonal shape of the supporting structure in particular, which is preferably supported on six piles that can be anchored in the seabed, is advantageous because it offers advantageous load transfer. The supporting structure is also highly rigid and stable, allowing the overall weight and therefore the quantity of materials used in the supporting structure to be reduced.
Pursuant to another aspect of the invention, or a preferred embodiment, the issue specified at the start will be resolved by a supporting structure, where the latticework segments are essentially constructed from HFIW tubes. HFIW (high-frequency induction welding) tubes are easy to manufacture, as sheets of metal are rolled, formed into tubes and then sealed along their length with an HFIW weld seam. Such tubes are easily available and inexpensive. The benefit of constructing the supporting structure from this type of tube is that costs can be reduced. Moreover, manufacturing times for this type of supporting structure are shortened because HFIW tubes are readily available on the market.
In another aspect or a preferred embodiment, the supporting structure resolves the issue specified above with a supporting structure, where some or all nodes in the prefabricated latticework segments are made of double-walled tube structures. It is easy to manufacture this type of double-walled tube structure. These tubes offer a simple method of connecting tubes. This type of double-walled tube structure will preferably be formed by initially heating a section of tube or tube shaft. A second section of tube, which has an external diameter that is essentially the same as the internal diameter of the heated tube shaft, is therefore inserted into the heated tube shaft. The tube shaft is shrunk by rapid cooling, forming a bond between the tube shaft and the tube section with the smaller diameter. The tube section with the smaller diameter is then positioned inside the tube shaft in such a way that a small part of it protrudes from the tube shaft, allowing a second tube to be pushed onto the protruding part of the tube section with the smaller diameter. Costs are further reduced by using this simple bonding method.
In one preferred embodiment, the supporting structure consists of six piles in the seabed, which are essentially positioned parallel to one another. The piles are arranged to support the supporting structure, which will preferably be tall enough that it essentially reaches from the seabed to the surface of the water. As the piles are essentially parallel to one another, and essentially perpendicular to the surface of the water, they are particularly easy to anchor in the seabed. They will preferably be of a length to provide secure under-pinning of the supporting structure.
Pursuant to another preferred embodiment, a latticework segment will be attached to the piles by multiple base nodes, where in each case, there will be one node on the upper end of a pile and one in a corner of the latticework segment. The supporting structure can therefore be connected using base nodes. Preferably, pursuant to this embodiment, there will be connector elements on the piles and on the base nodes that can be used to attach the supporting structure to the piles. These connector elements will preferably be designed such that manufacturing and assembly tolerances will be balanced. This allows for easy assembly.
These base nodes will preferably be laid out on one plane, which will be defined by the upper end sections of the piles sunk into the seabed. This plane will preferably be uniformly hexagonal.
It is particularly preferable that four tubes in the latticework structure can be attached to one another using the base nodes. Being able to attach four tubes with base nodes means the supporting structure will be very stable.
Pursuant to another preferred embodiment, at least one latticework segment will have a middle node in each corner, which can be used to attach the latticework segment to another latticework segment. The middle nodes therefore represent the point of connection between two latticework segments arranged one above the other. Here, being arranged one above the other refers to standard installation of the supporting structure on the seabed. An upper latticework segment therefore applies force on a lower latticework segment via the middle nodes. The middle nodes will preferably be arranged in such a way that they lie on one plane and define a uniform hexagon. Preferably, the middle nodes will also be aligned such that the hexagon they define will be arranged concentrically, with respect to the hexagon defined by the piles sunk into the seabed. This allows good force transmission and makes the supporting structure very stable.
Preferably, six tubes can be connected to one another using the middle node. Preferably, it will be possible to arrange two of these tubes so that they lie on the plane defined by the middle nodes, and another two will point upwards or point downwards and form part of the adjacent latticework segments. This will allow the best possible connection to adjacent latticework segments. It also stabilizes the supporting structure and reduces the quantity of materials required.
Preferably, each latticework segment will have at least one cross node, where a cross node is placed between the lower corners of a latticework segment and the upper corners of a latticework segment. These cross nodes are well suited as connector elements between two planes delimited by the latticework segments. A cross node is preferably also used on the supporting structure to transmit any torsional forces in effect. This increases stability further, but also means fewer materials are required.
Preferably, these cross nodes will have an essentially x-shaped structure.
Pursuant to another preferred embodiment, at least one latticework segment will have upper nodes on the upper corners, on which three tubes can be connected together. This type of latticework segment is particularly well-suited as the top segment. It will preferably form the end segment of the supporting structure, which reaches up to or above the surface of the water.
It is particularly preferred that the steel tubes be bonded to the respective nodes using orbital welding. This is particularly beneficial if the nodes are made of double-walled tube structures. A tube can then be slid over the protruding smaller tube of the node and bonded to the node using orbital welding. The tube shaft of the node will therefore preferably have essentially the same external diameter as the external diameter of the tube. Orbital welding is a process that is particularly well-suited for attaching this type of tube structure. It allows the supporting structure to be produced even more cost-effectively, thereby reducing costs. Furthermore, using orbital welding for weldseams produces higher quality goods, thereby improving the lifespan and load capacity of the supporting structure.
In another preferred embodiment, there will be an interface for mounting a wind energy installation tower above the latticework structure. The interface will preferably be located at a height which is above the surface of the sea. By using such an interface, the supporting structure can be connected to the tower particularly easily, thereby simplifying assembly.
It is also preferred that there be an accessible platform beneath the interface, located approximately in the area of the upper corner of the upper latticework segment. Such an accessible platform may be used as a landing stage for service ships. This type of platform will also allow access for maintenance staff who have to maintain the wind energy installation mounted on the supporting structure. This will make it easier to operate the supporting structure.
Pursuant to another embodiment, it is preferred that the tubes have a wall thickness of up to approximately 30 mm, preferably approximately in the range of 25.4 mm, and/or are manufactured using a hot-rolled wide strip process. Such wall thicknesses are particularly well suited to the supporting structure. They offer excellent stability without entailing the use of unnecessarily large quantities of materials. This also allows costs to be reduced. The hot-rolled wide strip process is also a simple way of manufacturing this type of tube. Preferably, the tubes will finally be attached using an HFIW weldseam.
In another preferred embodiment, the tubes will be at least partially coated with a coating, specifically with a plastic coating. The supporting structure is therefore adapted for use in the sea. The salt content of seawater makes it a highly corrosive environment for the supporting structure. Coating the supporting structure will protect it from corrosion, thereby improving the lifespan of the supporting structure. This also reduces maintenance costs.
It is particularly preferred that the supporting structure have six piles and three or four latticework segments. Three or four latticework segments are preferred numbers of segments, through which, on the one hand, a supporting structure of the correct height can be manufactured and, on the other hand, good stability can be achieved with few materials.
Preferably, the piles and bars of the latticework structure will be made of steel. Steel is a readily available material which guarantees good stability. Steel is also inexpensive.
When assembling a supporting structure in accordance with the invention, the following procedure is preferred. First, the working platform or nodes that can be attached to a working platform or that can form an interface to a wind energy installation is/are attached to an assembly stage. Such an assembly stage will preferably be height-adjustable. It will preferably be constructed on a ship or on land. The supporting structure will then be constructed from top to bottom. This means that the next step is, preferably, to attach the top segment beneath the working platform or any equivalent. This segment can also then be at least partially prefabricated and then assembled and fitted. Alternatively, individual steel tubes can be individually attached to the nodes fixed to the assembly stage. This will preferably be done using orbital welding. After one segment is completed, the next segment will be fitted. The segment with the base nodes will be the last segment to be fitted. Then the latticework structure constructed in this way can be mounted on the piles sunk into the seabed.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
By way of example, the invention is described in more detail below using some exemplary embodiments, with reference to the accompanying figures. The figures show the following:
FIG. 1 a first exemplary embodiment of an offshore foundation in a perspective view;
FIG. 2 a second exemplary embodiment of an offshore foundation in a perspective view;
FIG. 3 a third exemplary embodiment of an offshore foundation in a perspective view;
FIG. 4 a middle node;
FIG. 5 an upper node;
FIG. 6 a cross node; and
FIG. 7 a base node.
DETAILED DESCRIPTION OF THE INVENTION
According to FIG. 1 , the offshore supporting structure 1 for wind energy installations has six piles that can be anchored in the seabed (only two have reference numbers). A latticework structure 4 is attached to the plies 2 . The latticework structure 4 is designed to be essentially conical or frustum-shaped and essentially has a rectangular cross-section based on a longitudinal axis of the latticework structure 4 . It is connected by its six lower corners 3 a (only one has a reference number) to the six piles 2 . The latticework structure 4 has four segments 6 , 8 , 10 , 12 , which are placed above one another, essentially coaxially to one another. The latticework structure 4 as well as segments 6 , 8 , 10 , 12 are formed of tubes 14 (only one has a reference number), which are attached to one another by nodes 20 , 22 , 24 , 26 .
Each segment 6 , 8 , 10 , 12 is essentially conical or frustum-shaped and has a hexagonal cross-section, which accordingly is uniformly hexagonal. A segment 6 , 8 , 10 , 12 therefore has six lower corners 3 a , 3 b , 3 c ; 3 d and six upper corners 5 a , 5 b , 5 c , 5 d (only one of each corner type has a reference number). Therefore, for example, the lowest segment 6 has six lower corners 3 a (only one has a reference number) and six upper corners 5 a (only one has a reference number). The six upper corners 5 a of the lowest segment 6 simultaneously form the lower corners 3 b of the second lowest segment 8 . On the corners 3 a of the lowest segment are base nodes 20 while on the corners 3 b , 5 a , 3 c , 5 b , 3 d , and 5 c there are middle nodes 24 . The base nodes 20 and the middle nodes 24 are therefore each essentially connected to horizontally placed tubes 14 , thereby forming an essentially uniform hexagon. The upper corners 5 a , 5 b , 5 c , 5 d of each segment 6 , 8 , 10 , 12 are also connected to the lower corners 3 a , 3 b , 3 c , 3 d of each segment 6 , 8 , 10 , 12 via tubes 14 and cross nodes 22 in a vertical direction and spaced apart. The tubes 14 and the cross nodes 22 are therefore arranged on the latticework structure 4 so that they essentially lie in a lateral surface of the latticework structure 4 . The inside of the latticework structure 4 is therefore hollow or free of tubes and braces. The precise configuration of the individual nodes 20 , 22 , 24 , 26 can be seen in FIGS. 4 to 7 .
At the upper end of the supporting structure 1 , an interface 16 is positioned on the latticework structure 4 to hold a wind energy installation. The interface 16 is therefore attached to the upper nodes 26 of the top segment 12 . A working platform 18 is also located on the interface 16 . For example, service ships used by maintenance staff to reach the supporting structure 1 can land at this working platform in order to maintain one of the wind energy installations attached to it.
While the supporting structure 1 is particularly well-suited for large wind energy installations with high towers and high outputs, pursuant to the first exemplary embodiment ( FIG. 1 ), the supporting structures 1 are also well-suited for smaller wind energy installations, pursuant to the second and third exemplary embodiments ( FIGS. 2 and 3 ).
The embodiments regarding the supporting structures 1 , pursuant to the second and third exemplary embodiments ( FIG. 2 and FIG. 3 ), are identical and equipped with similar elements with the same reference numbers. In this respect, reference is comprehensively made to the above description of the supporting structure 1 , pursuant to the first exemplary embodiment ( FIG. 1 ).
The supporting structure, pursuant to the second exemplary embodiment ( FIG. 2 ), has six piles 2 that can be anchored in the seabed. The latticework structure 4 of the supporting structure 1 has three segments 6 , 8 , 10 , which are placed above one another, essentially coaxially to one another. All segments 6 , 8 , 10 have an essentially hexagonal cross-section, based on a longitudinal axis which is essentially formed according to a uniform hexagon. While the lowest segment 6 is therefore conical or frustum-shaped, both of the upper segments 8 , 10 are essentially cylindrical.
The latticework structure 4 and the segments 6 , 8 , 10 are formed, as in the first exemplary embodiment ( FIG. 1 ), of tubes 14 and nodes 20 , 22 , 24 , 28 . The upper nodes 28 , pursuant to the second exemplary embodiment ( FIG. 2 ), are slightly different from the upper nodes 26 , pursuant to the first exemplary embodiment ( FIG. 1 ). The reason for this is that the interface 16 for holding the wind energy installation, pursuant to the second exemplary embodiment, is designed slightly differently from the interface 16 , pursuant to the first exemplary embodiment.
The supporting structure 1 , pursuant to the third exemplary embodiment ( FIG. 3 ), has a latticework structure 4 formed of three segments 6 , 8 , 10 , which are essentially cylindrical with a hexagonal cross-section. Contrary to the first two exemplary embodiments ( FIGS. 1 and 2 ), the supporting structure 1 , pursuant to the third exemplary embodiment, only has four piles 2 that can be anchored in the seabed. The upper sections of the piles 2 are attached to specially-formed attachment braces 30 (only one has a reference number), so that the hexagonal segment 6 can be attached to the attachment braces 30 using base nodes 20 . Fitting the supporting structure 1 with only four piles 2 may be advantageous if the wind energy installation being mounted on the supporting structure 1 is smaller, or if the seabed does not allow more than four piles 2 to be driven in.
FIGS. 4 to 7 illustrate the various nodes 20 , 22 , 24 , 26 in detail. Pursuant to FIG. 4 , a middle node 24 is designed to be able to form one corner of a supporting structure 1 (not shown in FIGS. 4 to 7 ). The middle node 24 is designed as a double-walled tube structure and is constructed in order to connect six tubes 14 to one another. The tubes 14 are preferably HFIW tubes and attached to the middle nodes 24 using orbital weldseams.
The upper node 26 illustrated in FIG. 5 is essentially V- or Y-shaped and is constructed in order to connect three tubes 14 to one another. The tubes 14 are in turn attached by orbital welding to the nodes 26 (only one weldseam 15 has a reference number). The upper tube 14 shown in FIG. 5 is constructed so that it can be attached to a platform 18 or an interface 16 of the supporting structure 1 (not shown in FIG. 5 ). The two lower tubes (shown in FIG. 5 ) will preferably form part of a top segment 10 or 12 .
The cross node 22 shown in FIG. 6 is essentially X-shaped and includes two acute and two obtuse angles between its arms. The cross node 22 is constructed to connect four tubes 14 to one another. The tubes 14 are therefore connected to one another by the cross node such that they all lie essentially on one plane.
The base node 20 ( FIG. 7 ) is constructed to connect four tubes 14 to one another. The base node 20 also has an interface 21 for connecting to the piles 2 (not shown in FIG. 7 ).
All nodes 20 , 22 , 24 , 26 are preferably designed as double-walled tube structures. The tubes 14 are preferably attached using orbital welding to nodes 20 , 22 , 24 , 26 .
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This invention relates to an offshore supporting structure ( 1 ) for wind energy installations with multiple, preferably six, specifically tubular piles ( 2 ) that can be anchored in the seabed, and a latticework structure ( 4 ) assembled from multiple bars, specifically steel tubes ( 14 ). Pursuant to the invention, we propose that the latticework structure ( 4 ) be assembled from multiple, prefabricated latticework segments ( 6, 8, 10, 12 ), where each latticework segment ( 6, 8, 10, 12 ) has six lower corners ( 3 a, 3 b, 3 c, 3 d ) and six upper corners ( 5 a, 5 b, 5 c, 5 d ), where the upper corners ( 5 a, 5 b, 5 c ) of one latticework segment ( 6, 8, 10 ) can be attached to the lower corners ( 3 b, 3 c, 3 d ) of an adjacent latticework segment ( 8, 10, 12 ).
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BACKGROUND OF THE INVENTION
[0001] The present invention relates generally to an image sensor, and more particularly, to a photo detector device capable of detecting an image input from a stylus, pen, torch or a shadow.
[0002] With the rapid development in the high-tech industry, pen tablets have been widely applicable to Personal Digital Assistants (PDAs), Personal Computers (PCs) and other electrical appliances used in our daily life. Generally, a pen tablet includes one of a resistor-type, electromagnetic inductance-type, capacitor-type and optoelectronic-type writing panel. As an example of the conventional optoelectronic-type pen tablet, an optical signal is converted into electrical charges, which in turn is stored in a capacitor of a detector array including capacitors, optoelectronic components and switch transistors before it is subsequently read. The capacitors may require additional areas and therefore adversely reduce the aspect ratio of the panel. Furthermore, the charges generated by a background light source and an input signal are equally stored in the capacitor, adversely resulting in a relatively narrow dynamic range. It is therefore desirable to have a photo detector device that is able to convert an optical signal into a photocurrent, eliminating the storing capacitors used in the conventional panels.
BRIEF SUMMARY OF THE INVENTION
[0003] Examples of the invention may provide a photo detector device that comprises a photosensitive transistor capable of detecting an optical signal including an image component and a background component and converting the optical signal into a current including an image current corresponding to the image component and a background current corresponding to the background component, a first amplifier module electrically connected to the photosensitive transistor capable of canceling the background current and amplifying the image current, and a second amplifier module electrically connected to the first amplifier module capable of detecting a direct-current (dc) portion of the image current.
[0004] Examples of the invention may also provide a photo detector device that comprises a plurality of first conductive lines extending in parallel with each other, a plurality of second conductive lines extending in parallel with each other and being orthogonal to the plurality of first conductive lines, and an array of optical detectors each of which is disposed near one of the plurality of first conductive lines and one of the plurality of the second conductive lines, and comprises a photosensitive transistor capable of detecting an optical signal including an image component and a background component and converting the optical signal into a current including an image current corresponding to the image component and a background current corresponding to the background component, a first amplifier module electrically connected to the photosensitive transistor capable of canceling the background current and amplifying the image current, and a second amplifier module electrically connected to the first amplifier module capable of detecting a direct-current (dc) portion of the image current.
[0005] Some examples of the invention may also provide a photo detector device that comprises a substrate, a gate electrode over the substrate, an insulating layer over the gate electrode and the insulating layer, a semiconductor layer over the insulating layer, a first diffused region over the semiconductor layer, a second diffused region over the semiconductor layer, and a third diffused region over the semiconductor layer and the gate electrode between the first diffused region and the second diffused region, wherein the first diffused region, the gate electrode and the third diffused region form a first photosensitive transistor capable of detecting an optical signal, and the second diffused region, the gate electrode and the third diffused region form a second photosensitive transistor capable of detecting an optical signal.
[0006] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0007] 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 are shown in the drawings examples consistent with the invention. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown.
[0008] In the drawings:
[0009] FIG. 1A is a schematic circuit diagram of a photo detector array consistent with an example of the present invention;
[0010] FIG. 1B is an enlarged circuit diagram of a photosensitive transistor of the photo detector array illustrated in FIG. 1A ;
[0011] FIG. 1C is an enlarged circuit diagram of a first amplifier module of the photo detector array illustrated in FIG. 1A ;
[0012] FIG. 1D is an enlarged circuit diagram of a second amplifier module of the photo detector array illustrated in FIG. 1A ;
[0013] FIG. 1E is an enlarged circuit diagram of a third amplifier module of the photo detector array illustrated in FIG. 1A ;
[0014] FIG. 2A is a schematic diagram of a photo detector array consistent with another example of the present invention;
[0015] FIG. 2B is an enlarged circuit diagram of a photosensitive transistor and a switching transistor of the photo detector array illustrated in FIG. 2B ;
[0016] FIG. 2C is a schematic cross-sectional diagram of a photo detector array incorporated in a thin film transistor liquid crystal display panel consistent with an example of the present invention;
[0017] FIGS. 3A and 3B are respectively a cross-sectional view and a top view of a photo detector device consistent with examples of the present invention;
[0018] FIG. 3C is a top view of a conventional photo detector device;
[0019] FIGS. 4A and 4B are respectively a cross-sectional view and a top view of a photo detector device consistent with examples of the present invention; and
[0020] FIG. 4C is a top view of another conventional photo detector device.
DETAILED DESCRIPTION OF THE INVENTION
[0021] Reference will now be made in detail to the present embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
[0022] FIG. 1A is a schematic circuit diagram of a photo detector array 10 consistent with an example of the present invention. Referring to FIG. 1A , the photo detector array 10 includes a photosensitive transistor array 14 , and a first amplifier module 11 , a second amplifier module 12 and a third amplifier module 13 electrically connected to each row of the photosensitive transistor array 14 . The photosensitive transistor array 14 includes a plurality of photosensitive transistors 14 - 1 formed in rows and columns. A representative photosensitive transistor 14 - 1 is disposed near an intersection of one of a plurality of gate lines 14 -G and one of a plurality of data lines 14 -D orthogonal to the gate lines 14 -G. Each of the plurality of data lines 14 -D is electrically connected to the first amplifier module 11 , which in turn is electrically connected to the second amplifier module 12 and the third amplifier module 13 connected in parallel with the second amplifier module 12 . The photo detector array 10 may further include a first detector 15 - 1 and a second detector 15 - 2 , which are electrically connected to the second amplifier module 12 and the third amplifier module 13 , respectively.
[0023] FIG. 1B is an enlarged circuit diagram of the photosensitive transistor 14 - 1 of the photo detector array 10 illustrated in FIG. 1A . The photosensitive transistor 14 - 1 functions to detect light and serve as a switch. Referring to FIG. 1B , the photosensitive transistor 14 - 1 includes a first electrode 141 , a second electrode 142 and a gate electrode 143 . The first electrode 141 , which serves as a drain of the photosensitive transistor 14 - 1 , is connected to the gate line 14 -G. The second electrode 142 , which serves as a source of the photosensitive transistor 14 - 1 , is connected to the data line 14 -D. The gate electrode 143 is connected to the gate line 14 -G and thus is short-circuited to the first electrode 14 - 1 , which advantageously prevents parasitic capacitance from accumulation therebetween. In the absence of an input optical signal provided from, for example, a light source such as a stylus or torch, a pressure source such as a force applied from an ordinary pen or fingertip, or even the shadow of an object, only the background light will be detected by the photosensitive transistor 14 - 1 if the gate line 14 -G is selected. The background light is converted to a photo current I B , which is generally a relatively small current. In the presence of an input optical signal, the photosensitive transistor 14 - 1 generates a current I if the gate line 14 -G is selected. The current I includes an image current I M due to the input optical signal and the photo current I B due to the background light. The current I is provided to the first amplifier module 11 .
[0024] FIG. 1C is an enlarged circuit diagram of the first amplifier module 11 of the photo detector array 10 illustrated in FIG. 1A . Referring to FIG. 1C , the first amplifier module 11 includes a first variable resistor 111 , a second variable resistor 112 , a capacitor 113 , an operational amplifier 114 and a resistor 115 . The first amplifier module 11 functions to obtain the image current I M out of the current I by removing the photo current I B . The resistance of the first variable resistor 111 varies as the photo current I B varies. Specifically, the resistance of the first variable resistor 111 is automatically adjusted in response to the variation in the background light intensity so as to provide differential signal compensation. Therefore, the photo current I B is cancelled in the operational amplifier 114 due to a differential amplifier circuit function. As a result, interference caused by the background light is minimized, which enhances the system sensitivity and expands the dynamic range of the photo detector array 10 .
[0025] In the absence of an input optical signal, the first variable resistor 111 maintains an output voltage of the first amplifier module 11 at a stable level. That is, the gain of the first amplifier module 11 may be designed with a substantially large value (but not infinite) such that the signal response is sensitive enough to determine whether an input optical signal is light or shadow. In one example consistent with the present invention, when an output value is smaller than the level, it is determined that an input optical signal is provided by a stylus. Furthermore, when an output value is greater than the level, it is determined that an input optical signal is provided by a shadow. In another example, when an output value is greater than the level, it is determined that an input optical signal is provided by a stylus. Furthermore, when an output value is smaller than the level, it is determined that an input optical signal is provided by a shadow. In still another example, the stable level is a gray scale value 128, given 8 bits per pixel. A relatively white-color optical input signal has a gray scale value ranging from 128 to 255, while a relatively black-color optical input signal has a gray scale value ranging from 0 to 128. The compensation process therefore compensates for the variation in the background light and the differences of optoelectronic characteristics of the plurality of photosensitive transistors 14 - 1 as well. Consequently, the output voltage of each of the plurality of photosensitive transistors 14 - 1 of the photo detector array 10 is maintained at a stable level in the absence of an input optical signal. Therefore, a stylus may be used as an entry tool. Similarly, the shadow of finger, chopstick or ordinary pen may also serve as an entry tool. In one example, an input optical signal having a diameter of approximately 3 millimeter or greater is detectable by the photo detector array 10 .
[0026] FIG. 1D is an enlarged circuit diagram of the second amplifier module 12 of the photo detector array 10 illustrated in FIG. 1A . Referring to FIG. 1D , the second amplifier module 12 includes a first resistor 121 , a second resistor 122 , a capacitor 123 and an operational amplifier 124 . The second resistor 122 and the capacitor 123 form a low pass filter. The second amplifier module 12 functions to process a direct-current (dc) component of a signal provided by the first amplifier module 11 . Specifically, the second amplifier module 12 filters out or attenuates frequencies higher than the cutoff frequency of the low pass filter, thereby reducing the high-frequency noise in the dc component. The dc component is generated by an optical input through, for example, a general stylus, pen, torch, finger or chopstick. In one example consistent with the present invention, the photo detector array 10 includes an analog-to-digital converter (not shown) of a multiplexer (not shown) electrically connected to the second amplifier module 12 at a subsequent stage to further process the dc component.
[0027] FIG. 1E is an enlarged circuit diagram of the third amplifier module 13 of the photo detector array 10 illustrated in FIG. 1A . Referring to FIG. 1E , the third amplifier module 13 includes a first resistor 131 , a second resistor 132 , a first capacitor 133 , a second capacitor 135 and an operational amplifier 134 . The third amplifier module 13 functions to serve as a band pass filter, and process an alternating-current (ac) component of a signal provided by the first amplifier module 11 . The ac component is generated by an optical input through, for example, a dedicated stylus having a specific output specification such as frequency. The third amplifier module 13 is able to detect a modulated optical signal from the dedicated stylus, which converts a force applied therethrough on a panel into a frequency. In one example consistent with the present invention, the photo detector array 10 includes a phase-locked-loop (“PLL”) circuit (not shown) electrically connected to the third amplifier module 13 at a subsequent stage to convert the frequency of the dedicated stylus into a voltage signal.
[0028] Referring to FIG. 1A , each of the first detector 15 - 1 and the second detector 15 - 2 includes a diode (not numbered) and a low pass filter (not numbered) connected in parallel with the diode. The second detector 15 - 2 is able to detect the amplitude of the signal from the third amplifier module 13 .
[0029] FIG. 2A is a schematic diagram of a photo detector array 20 consistent with another example of the present invention. Referring to FIG. 2A , the photo detector array 20 is similar to the photo detector array 10 illustrated in FIG. 1A except a photosensitive transistor array 24 . The photosensitive transistor array 24 includes a plurality of photosensitive transistors 24 - 1 and a plurality of switching transistors 24 - 2 formed in rows and columns. A representative photosensitive transistor 24 - 1 and a representative switching transistor 24 - 2 are disposed near an intersection of one of a plurality of gate lines 24 -G and one of a plurality of data lines 24 -D orthogonal to the gate lines 24 -G.
[0030] FIG. 2B is an enlarged circuit diagram of the photosensitive transistor 24 - 1 and the switching transistor 24 - 2 of the photo detector array 20 illustrated in FIG. 2B . Referring to FIG. 2B , the photosensitive transistor 24 - 1 includes a first electrode 241 , a second electrode 242 and a gate electrode 243 , which serve as a drain, source and gate of the photosensitive transistor 24 - 1 , respectively. The first electrode 241 and the gate electrode 243 are short-circuited to prevent parasitic capacitance from accumulation therebetween. The switching transistor 24 - 2 includes a first electrode 242 , a second electrode 244 and a gate electrode 245 , which serve as a drain, source and gate of the switching transistor 24 - 2 , respectively. The gate electrode 245 is connected to the gate line 24 -G, and the second electrode 244 is connected to the data line 24 -D. In the absence of an input optical signal provided from, for example, a stylus, an ordinary pen, a torch, a fingertip or even the shadow of an object, only the background light will be detected by the photosensitive transistor 24 - 1 if the gate line 24 -G is selected, which turns on the switching transistor 24 - 2 and the photosensitive transistor 24 - 1 . The background light is converted to a photo current I B . In the presence of an input optical signal, the photosensitive transistor 24 - 1 generates a current I if the gate line 24 -G is selected. The current I includes an image current I M due to the input optical signal and the photo current I B due to the background light. The current I is provided to the first amplifier module 11 .
[0031] FIG. 2C is a schematic cross-sectional diagram of the photo detector array 24 incorporated in a thin film transistor liquid crystal display panel 21 consistent with an example of the present invention. Referring to FIG. 2C , the panel 21 includes a pair of polarizers 201 , 202 , a pair of glass substrates 203 , 204 , a pair of alignment films 205 , 206 , a color filter film 207 , a common electrode 208 , a liquid crystal cell 209 , a backlight unit 210 and a thin film transistor (“TFT”) layer 211 . The photo detector array 24 is formed in the TFT layer 211 . In one example consistent with the present invention, the gate lines 24 -G illustrated in FIG. 2B serve as a portion of gate lines for switching transistors in the TFT layer 211 .
[0032] FIGS. 3A and 3B are respectively a cross-sectional view and a top view of a photo detector device 30 consistent with examples of the present invention. Referring to FIG. 3A , the photo detector device 30 includes a substrate 31 , a gate electrode “G” over the substrate 31 , an insulating layer 32 over the gate electrode G, a semiconductor layer 33 over the insulating layer 32 , and a first source electrode “S 1 ”, a drain electrode “D” and a second source electrode “S 2 ” over the semiconductor layer 33 . To avoid accumulation of parasitic capacitance, the drain electrode D and the gate electrode G are coupled to one another as illustrated in FIG. 1A . In the present example, the gate electrode G is aligned with the first source electrode S 1 and the second source electrode S 2 . In other examples, the gate electrode G may cross over a portion of the first source electrode S 1 or the entire first source electrode S 1 . Similarly, the gate electrode G may cross over a portion of the second source electrode S 2 or the entire second source electrode S 2 . Referring to FIG. 3B , the photo detector device 30 includes two channel widths “W” and therefore two folds of channel width-to-length ratio, i.e., 2 (W/L), L being the channel length, in five unit areas, each of which is substantially equal to a source or drain electrode area.
[0033] FIG. 3C is a top view of a conventional photo detector device 31 . To achieve the same two folds of channel width-to-length ratio, a total number of six unit areas are required in the conventional photo detector device 31 , including a first channel width defined by a first set of source, drain and gate electrodes S′, D′ and G′, respectively, and a second channel width defined by a second set of source, drain and gate electrodes S″, D″ and G″, respectively. By comparison, the photo detector device 30 illustrated in FIG. 3A or 3 B is more area effective than the conventional photo detector device 31 .
[0034] FIGS. 4A and 4B are respectively a cross-sectional view and a top view of a photo detector device 40 consistent with examples of the present invention. Referring to FIG. 4A , the photo detector device 40 includes a substrate 41 , a first gate electrode “G 1 ” and a second gate electrode “G 2 ” over the substrate 41 , an insulating layer 42 over the gate electrodes G 1 and G 2 , a semiconductor layer 43 over the insulating layer 42 , and a first source electrode “S 1 ”, a first drain electrode D 1 , a second drain electrode D 2 and a second source electrode S 2 over the semiconductor layer 43 . The first gate electrode G 1 and the second gate electrodes G 2 are the gates of a photosensitive transistor and a switching transistor, respectively. To avoid accumulation of parasitic capacitance, the first drain electrode D 1 and the first gate electrode G 1 are coupled to one another as illustrated in FIG. 2A . The first gate electrode G 1 may overlap the first source electrode S 1 or the second drain electrode D 2 or both. The second gate electrode G 2 is aligned with the second source electrode S 2 and the second drain electrode D 2 . In other examples, however, the second gate electrode G 2 may cross over a portion of the second source electrode S 2 or the entire second source electrode S 2 . Similarly, the second gate electrode G 2 may cross over a portion of the second drain electrode D 2 or the entire second drain electrode D 2 . Referring to FIG. 4B , the photo detector device 40 includes two channel widths “W” and therefore two folds of channel width-to-length ratio, i.e., 2 (W/L), in seven unit areas.
[0035] FIG. 4C is a top view of another conventional photo detector device 41 . To achieve the same two folds of channel width-to-length ratio, a total number of eight unit areas are required in the conventional photo detector device 41 , including a first channel width defined by a first set of source, drain and gate electrodes S′, D′ and G′, respectively, and a second channel width defined by a second set of source, drain and gate electrodes S″, D″ and G″, respectively. A third transistor including S′″, G′″ and S′″ serves as a switching transistor. By comparison, the photo detector device 40 illustrated in FIG. 4A or 4 B is more area effective than the conventional photo detector device 41 .
[0036] It will be appreciated by those skilled in the art that changes could be made to one or more of the examples described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular examples disclosed, but it is intended to cover modifications within the scope of the present invention as defined by the appended claims.
[0037] Further, in describing certain illustrative examples of the present invention, the specification may have presented the method and/or process of the present invention as a particular sequence of steps. However, to the extent that the method or process does not rely on the particular order of steps set forth herein, the method or process should not be limited to the particular sequence of steps described. As one of ordinary skill in the art would appreciate, other sequences of steps may be possible. Therefore, the particular order of the steps set forth in the specification should not be construed as limitations on the claims. In addition, the claims directed to the method and/or process of the present invention should not be limited to the performance of their steps in the order written, and one skilled in the art can readily appreciate that the sequences may be varied and still remain within the spirit and scope of the present invention.
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A photo detector device includes a photosensitive transistor capable of detecting an optical signal including an image component and a background component and converting the optical signal into a current including an image current corresponding to the image component and a background current corresponding to the background component, a first amplifier module electrically connected to the photosensitive transistor capable of canceling the background current and amplifying the image current, and a second amplifier module electrically connected to the first amplifier module capable of detecting a direct-current (dc) portion of the image current.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This application is a continuation-in-part of application Ser. No. 06/713,116 filed Mar. 18, 1985. now abandoned.
This invention relates to prostacyclin derivatives and to a process for preparing them. More particularly the invention relates to novel prostacyclin (PGI 2 ) derivatives. More particularly, this invention relates to PGI 2 derivatives of formula I, Chart A with discloses allenic carbacyclins.
2. Description of Prior Art
The prostaglandins, prostacyclins, carbacyclins, and their analogs are well-known organic compounds derived from prostanoic acid which was the structure and atom numbering shown in figure II chart A.
As drawn hereinafter the formulas represent a particular optically active isomer having the same absolute configuration as PGI 2 . However, both the R and S configuration at carbon 15 (bearing the hydroxyl group) or mixtures are included within the scope of this invention.
In the formulas, broken line attachments to the cyclopentane ring or side chain indicate substituents in alpha configuration, i.e. below the plane of the cyclopentyl ring or side chain. Heavy solid line attachments indicate substitutents in beta configuration, i.e. above the plane.
For background on prostaglandins, see for example Bergstrom et al., Pharmacol. Rev. 20, 1 (1968). For related compounds see Pace-Asciak et al., Biochem., 10 3657 (1971). Related compounds are described in a publication on 6-keto-prostaglandin F 1 α by Pace-Asciak, J. Am. Chem. Soc. 2348 (1976) and a publication on "PGX" (6,9α-oxido-9α,15α-dihydroxyprosta(Z)5,(E)13-dienoic acid) by E. J. Corey et al., J. Am. Chem. Soc. 99 20016 (1977).
The potential pharmaceutical value of prostacyclins and prostacyclin analogs is described by S. Moncada. Br. J. Pharmac. (1982), 76, 003-031 and by Honn et al. (U.K.) Biochemical Pharmacology (1983) 32, No. 1, 1-11.
The compounds of this invention may be regarded as analogs of prostacyclin and prostacyclin type compounds.
Prostacyclin, an organic compound related to prostaglandins, is (5Z)-9-deoxy-6,9α-epoxy-Δ 5 -PGF 1 . For its synthesis and structure see for example R. A. Johnson et al., J. Am. Chem. Soc. 99, 4182 (1977) and Prostaglandins, 12, 915 (1976), and E. J. Corey et al., cited above. For some of its biological properties uses see the references cited in the Johnson references.
Prostaglandins and prostacyclin-type compounds, including derivatives and analogs, are extremely potent in causing various biological responses. For that reason, these compounds are useful for pharmacological purposes. A few of those biological responses are: inhibition of blood platelet aggregation, stimulation of smooth muscle, inhibition of gastric secretion, inhibition of tumor cell metastasis, and reduction of undesirable gastrointestinal effects from systemic administration of prostaglandin synthetase inhibitors.
Because of these biological responses, prostaglandins and prostacyclin-type compounds are useful to study, prevent, control, or alleviate a wide variety of diseases and undersirable physiological conditions in mammals, including humans, useful domestic animals, pets, and zoological specimens, and in laboratory animals, for example, mice, rats, rabbits, and monkeys.
Prostacyclin and prostacyclin-type compounds are useful whenever it is desired to inhibit platelet aggregation, to reduce the adhesive character of platelets, and to remove or prevent the formation of thrombi or tumor cell metastasis in mammals, including man, rabbits, and rats. For example, these compounds are useful in the treatment and prevention of myocardial infarcts, to treat and prevent postoperative surgery, and to treat conditions such as atherosclerosis, hypertension, arteriosclerosis, blood clotting defects due to lipemia, and other clinical conditions in which the underlying etiology is associated with lipid imbalance or hyperlipidemia. Other in vivo applications include geriatric patients to prevent cerebral ischemic attacks and long term prophylaxis following myocardial infarcts and strokes. For these purposes, these compounds are administered systemically, e.g., intravenously, subcutaneously, intramuscularly, and in the form of sterile implants for prolonged action. For rapid response, especially in emergency situations, the intravenous route of administraton is preferred. Doses in the range about 0.01 to about 10 mg. per kg. of body weight per day are used, the exact dose depending on the age, weight, and condition of the patient or animal, and on the frequency and route of administration.
The addition of prostacyclin and prostacyclin-type compounds to whole blood provides in vitro applications such as storage of whole blood to be used in heart lung machines. Additionally, Whole blood containing these compounds can be circulated through limbs and organs, e.g. heart and kidneys, whether attached to the original body, detached and being preserved or prepared for transplant, or attached to a new body. Blocking of aggregated platelets is avoided by the presence of these compounds. For this purpose, the compound is added gradually or in single or multiple portions to the circulating blood, to the blood of the donor person or animal, to the perfused body portion, attached or detached, to the perfused body portion, attached or detached, to the recipient, or to two or all of those at a whole blood. These compounds are also useful in preparing platelet-rich concentrates from blood for use in treating thrombocytopenia or in chemotherapy.
Prostaglandins E and F and related compounds are extremely potent in causing stimulation of smooth muscle, and are also highly active in potentiating other known smooth muscle stimulators, for example, oxytocic agents, e.g., oxytocin, and the various ergot alkaloids including derivatives and analogs thereof. Therefore, they are useful in place of or in combination with less than usual amounts of these known smooth muscle stimulators, for example, to relieve the symptoms of paralytic ileus, or to control or prevent atonic uterine bleeding after abortion or delivery, to aid in expulsion of the placenta, and during the puerperium. For the later purpose, the compound is administered by intravenous infusion immediately after abortion or delivery at a dose in the range about 0.01 to about 50 μg. per kg. of body weight per minute until the desired effect is obtained. Subsequent doses are given by intravenous, subcutaneous, or intramuscular injection or infusion during puerperium in the range 0.01 to 2 mg. per kg. of body weight per say, the exact dose depending on the age, weight, and condition of the patient or animal.
Prostaglandins and prostacyclin-type compounds are also useful in mammals, including man and certain useful animals, e.g. dogs and pigs, to reduce and control excessive gastric secretion, thereby reduce or avoid gastrointestinal ulcer formation, and accelerate the healing of such ulcers already present in the gastrointestinal tract. For this purpose, these compounds are injected or infused intravenously, subcutaneously, or intramuscularly in an infusion dose range about 0.1 μg. per kg. of body weight per minute, or in a total daily dose by injection of infusion in the range about 0.01 to about 10 mg. per kg. of body weight per day, the exact dose depending on the age, weight, and condition of the patient or animal, and on the frequency and route of administration.
Prostaglandins and prostacyclin-type compounds and their analogs are also useful in mammals, including man, to treat primary neoplasms and other cancers or tumors by inhibiting the production of metastasis away from the primary lesion. These compounds can be used singularly or in combination with other anti-metastatic treatment such as chemotherapy and radiation therapy. See Honn et al., Biochemical Pharmacology, 32, 1-11 (1983), for mechanisms by which prostacyclins (PGI 2 ) are thought to prevent the metastasis by inhibiting the association of the released tumor cells with platelets and/or the blood vessel wall thereby inhibiting the formation of new metastatic foci away from the primary lesion.
To treat with an anti-metastatic amount of the prostaglandin or prostacyclin type compound, the compound is administered by infusion or injection, intravenously, subcutaneously or intramuscularly in an infusion dose range of about 0.001-50 mg/kg of body weight per minute, or in a total daily dose by injection in the range of about 0.01 to 10 mg/kg of body weight per day, the exact dose depending upon the age, weight and condition of the patient or animal, and on the frequency and route of administration.
Prostaglandins and prostacyclin-type compounds are also useful in reducing the undesirable gastrointestinal effects resulting from systemic administration of anti-inflammatory prostaglandin synthetase inhibitors, and are used for that purpose by concomitant administration of prostaglandins or prostacyclin-type compound and anti-inflammatory prostaglandin synthetase inhibitor. See Partridge et al., U.S. Pat. No. 3,781,429, for a disclosure that the ulcerogenic effect induced by certain non-steroidal and steroidal anti-inflammatory agents in rats is inhibited by concomitant oral administration of certain prostaglandins of the E and A series, including PGE 1 , PGE 2 , PGE 3 , 13,14-dihydro-PGE 1 , and the corresponding 11-deoxy-PGE and PGA compounds. Prostaglandins and prostacyclin-type compounds are useful, for example, in reducing the undesirable gastrointestinal effects resulting from systemic administration of indomethacin, phenylbutazone, and aspirin. These are substances specifically mentioned in Partridge et al., as non-steroidal, anti-inflammatory agents. These are also known to be prostaglandin synthetase inhibitors.
The anti-inflammatory cyclooxygenase inhibitor, for example indomethacin, aspirin, or phenylbutazone, is administered in any of the ways known in the art to alleviate an inflammatory condition, for example, in any dosage regimen and by any of the known routes of systemic administration.
The prostaglandins or prostacyclin-type compound is administered along with the anti-inflammatory prostaglandin synthetase inhibitor either by the same route of administration or by a different route. For example, if the anti-inflammatory substance is being administered orally, the prostaglandins or prostacyclin-type compound is also administered orally, or alternatively, as administered rectally in the form of a suppository or, in the case of women, vaginally in the form of a suppository or a vaginal device for slow release, for example as described in U.S. Pat. No. 3,545,439. Alternatively, if the anti-inflammatory substance is being administered rectally, the prostaglandin or prostacyclin-type compound is also administered rectally. Further, the prostaglandin or prostacyclin derivative can be conveniently administered orally or, in the case of women, vaginally. It is especially convenient when the administration route is to be the same for both anti-inflammatory substance and prostaglandin or prostacyclin-type compound to combine both into a single dosage form.
The dosage regimen for the prostaglandin or prostacyclin-type compound in accord with this treatment will depend upon a variety of factors, including the type, age, weight, sex and medical condition of the mammal, the nature and dosage regimen of anti-inflammatory synthetase inhibitor being administered to the mammal, the sensitivity of the particular prostaglandin or prostacyclin-type compound to be administered. For example, not every human in need of an anti-inflammatory substance experiences the same adverse gastrointestinal effects when taking the substance. The gastrointestinal effects will frequently vary substantially in kind and degree. But it is within the skill of the attending physician or veterinarian to determine that administration of anti-inflammatory substance is causing undersirable gastrointestinal effects in the human or animal subject and to prescribe an effective amount of the prostaglandin or prostacyclin-type compound to reduce and then substantially to eliminate those undesirable effects.
Prostaglandin or prostacyclin-type compounds are also useful in the treatment of asthma. For example, these compounds are useful as bronchodilators or as inhibitors of mediators, such as SRS-A, and histamine which are released from cells activated by an antigen antibody complex. Thus, these compounds control spasm and facilitate breathing in conditions such as bronchial asthma, bronchitis, pneumonia and emphysema. For these purposes, these compounds are administered in a variety of dosage forms, e.g., orally in the form of tablets, capsules, or liquids; rectally in the form of suppositories; parenterally, subcutaneously, or intramuscularly, with intravenous administration being preferred in emergency situations; by inhalation in the form of aerosols or solutions for nebulizers; or by insufflation in the form of powder. Doses in the range of about 0.01 to 5 mg. per kg. of body weight are used 1 to 4 times a day, the exact dose depending on the age, weight, and condition of the patient and on the frequency and route of administration. For the above use the prostaglandin or prostacyclin-type compound can be combined advantageously with other asthmatic agents, such as sympathomimetics (isoproterenol, phenylephedrine, ephedrine, etc.); xanthine derivatives (theophylline and aminophylline); and corticosteroids (ACTH and prednisolone).
prostaglandin or prostacyclin-type compounds are effectively administered to human asthma patients by oral inhalation or aerosol inhalation.
For administration by the oral inhalation route with conventional nebulizers or by oxygen aerosolization it is convenient to provide the prostacyclin ingredient in dilute solution, preferably at concentrations of about 1 part of medicament to form about 100 to 200 parts by weight of total solution. Entirely conventional additives may be employed to stablize these solutions or to provide isotonic media, for example, sodium chloride, sodium citrate, citric acid, and the like can be employed.
For administration as a self-propelled dosage unit for administering the active ingredient in aerosol form suitable for inhalation therapy the composition can comprise the above ingredient suspended in an inert propellant (such as a mixture of dichloro-difluoromethane and dichloro-tetrafluoroethane) together with a co-solvent, such as ethanol, flavoring materials and stabilizers. Instead of a co-solvent there can be used a dispensing agent such as oleyl alcohol. Suitable means to employ the aerosol inhalation therapy technique are described fully in U.S. Pat. No. 2,868,691 for example.
Prostaglandins or prostacyclin-type compounds are useful in mammals, including man, as nasal decongestants and are used for this purpose in a dose range of about 10 μg. to about 10 mg. per ml. of a pharmacologically suitable liquid vehicle or as an aerosol spray, both for topical application.
Prostacyclin or prostacyclin-type compounds are also useful in treating peripheral vascular disease in humans. The term peripheral vascular disease as used herein means disease of any of the blood vessels outside of the heart, the microvasculature serving the heart and to disease of the lymph vessels, for example, frostbite, ischemic cerebrovascular disease, arteriovenous fistulas, ischemic leg ulcers, phlebitis, venous insufficiency, gangrene, hepatorenal syndrome, ductus arteriosus, nonobstructive mesenteric ischemia, artritis lymphangitis and the like. These examples are included to be illustrative and should not be construed as limiting the term peripheral vascular disease. For these conditions the prostacyclin compounds are administered orally or parentally via injection or infusion directly into a vein or artery.
The dosages of such compounds are in the range of 0.01-10 μg. administered by infusions at an hourly rate or by injection on a daily basis, i.e. 1-4 times a day, the exact dose depending on the age, weight, and condition of the patient and on the frequency and route of administration. Treatment is continued for one to five days, although three days is ordinarily sufficient to assure long-lasting therapeutic action. In the event that systemic or side effects are observed the dosage is lowered below the threshold at which such systemic or side effects are observed.
Prostacyclin or prostacyclin-type compounds are accordingly useful for treating peripheral vascular diseases in the extremities of humans who have circulatory insufficiencies in said extremities, such treatment affording relief of rest pain and induction of healing of ulcers.
For a complete discussion of the nature of and clinical manifestations of human peripheral vascular disease and the method previously known of its treatment with prostaglandins see South African Pat. No. 74/0149 referenced as Derwent Farmdoc No. 58,400V. See Elliott et al., Lancet, Jan. 18, 1975, pp. 140-142. Prostaglandins or prostacyclin-type compounds are useful in place of oxytocin to induce labor in pregnant female animals with intrauterine death of the fetus from about 20 weeks to term. For this purpose, the compound is infused intravenously at a dose of 0.01 to 50 μg. per kg. of body weight per minute until or near the termination of the second stage of labor i.e., expulsion of the fetus. These compounds are especially useful when the female is one or more weeks post-mature and natural labor has not started, or 12 to 60 hours after the membranes have ruptured and natural labor has not yet started. An alternative route of administration is oral.
Prostaglandins or prostacyclin type compounds are further useful for controlling the reproductive cycle in menstruating female mammals, including humans. By the term menstruating female mammals is meant animals which are mature enough to menstruate, but not so old that regular menstruation has ceased. For that purpose the prostaglandin compound is administered systemically at a dose level in the range 0.01 mg. to about 20 mg. per kg. of body weight of the female mammal, advantageously during a span of time starting approximately at the time of ovulation and ending approximately at the time of menses or just prior to menses. Intravaginal and intrauterine routes are alternate methods of administration. Additionally, expulsion of an embryo or a fetus is accomplished by similar administration of the compound during the first or second trimester of the normal mammalian gestation period.
Prostaglandin or prostacyclin-type compounds are further useful in causing cervical dilation in pregnant and nonpregnant female mammals for purposes of gynecology and obstetrics. In labor induction and in clinical abortion produced by these compounds, cervical dilation is also observed. In cases of infertility, cervical dilation produced by these compounds is useful in assisting sperm movement to the uterus. Cervical dilation by prostaglandin compounds is also useful in operative gynecology such as D and C (Cervical Dilation and Uterine Curettage) where mechanical dilation may cause perforation of the uterus, cervical tears, or infections. It is also useful for diagnostic procedures where dilation is necessary for tissue examination. For these purposes, the prostacyclin compound is administered locally or systemically.
The prostaglandin compound, for example, is administered orally or vaginally at doses of about 5 to 50 mg. per treatment of an adult female human, with from one to five treatments per 24 hour period. Alternatively the compound is administered intramuscularly or subcutaneously at doses of about one to 25 mg. per treatment. The exact dosages for these purposes depend on the age, weight, and condition of the patient or animal.
Prostaglandins and prostacyclin-type compounds are further useful in domestic animals as abortifacients (especially for feedlot heifer), as an aid to estrus detection, and for regulation or synchronization of estrus. Domestic animals include horses, cattle, sheep, and swine. The regulation or synchronization of estrus allows for more efficient management of both conception and labor by enabling the herdsman to breed all his females in short pre-defined intervals. This synchronization results in a higher percentage of live births than the percentage achieved by natural control. The prostaglandin or prostacyclin-type compound is injected or applied in a feed at doses of 0.1-100 mg. per animal and may be combined with other agents such as steroids. For example, mares are given the prostaglandin compound 5 to 8 days after ovulation and return to estrus. Cattle are treated at regular intervals over a 3 week period to advantageously bring all into estrus at the same time.
Prostaglandin or prostacyclin-type compounds increase the flow of blood in the mammalian kidney, thereby increasing volume and electrolyte content of the urine. For that reason, these compounds are useful in managing cases of renal dysfunction, especially those involving blockage of a renal vascular bed. Illustratively, these compounds are useful to alleviate and correct cases of edema resulting, for example, from massive surface burns, and in the management of shock. For these purposes, these compounds are preferably first administered by intravenous injection at a dose in the range 10 to 1000 μg. per kg. of body weight or 0.001 to 10 μg. per kg. of body weight per minute until the desire effect is obtained. Subsequent doses are given by intravenous, intramuscular, or subcutaneous injection or infusion in the range 0.05 to 2 mg. per kg. of body weight per day.
Prostaglandin or prostacyclin-type compounds are useful for treating proliferating skin diseases of man and domesticated animals, including psoriasis, atopic dermatitis, non-specific dermatitis, primary irritant contact dermatitis, allergic contact dermatitis, basal and squamous cell carcinomas of the skin, lamellar ichthyosis, epidermolytic hyperkeratosia, premalignant sun-induced keratosis, nonmalignant keratosis, acne, and seborrheic dermatitis in humans and atopic dermatitis and mange in domesticated animals. These compounds alleviate the symptoms of these proliferative skin disease: psoriasis, for example, being alleviated when a scale-free psoriasis lesion is noticeably decreased in thickness or noticeably but incompletely cleared or completely cleared.
For those purposes, such compounds are applied topically as compositions including a suitable pharmaceutical carrier, for example as an ointment, lotion, paste, jelly, spray, or aerosol, using topical bases such as petrolatum, lanolin, polyethylene glycols, and alcohols. These compounds, as the active ingredients, constitute from about 0.1% to about 15% by weight of the composition, preferably from about 0.5% to about 2%. In addition to topical administration, injection may be employed, as intradermally, intra- or perilesionally, or subcutaneously, using appropriate sterile saline compositions.
Prostaglandin or prostacyclin-type compounds are useful as antiflammatory agents for inhibiting chronic inflammation in mammals including the swelling and other unpleasant effects thereof using methods of treatment and dosages generally in accord with U.S. Pat. No. 3,885,041, which patent is incorporated herein by reference.
Antiplatelet substances such as PGI 2 are known and have been used to afford relief from the aggregate condition.
PGI 2 is a notably unstable substance. Although effective, PGI 2 often affords unwanted hypotensive effects. However, there may be occasions when such a hypotensive effect is desirable, such as in the treatment of hypertension. Also the antiplatelet aggregation effect is short lived (and the hazardous condition associated with uncontrolled platelet aggregation returns quickly). The stability of PGI 2 as a medicine is not satisfactory because its half life at physiological pH is only about several minutes. The instability of PGI 2 is considered to be due to the fact that chemically the vinyl ether structure containing a double bond at Δ 5 is readily hydrated to 6-oxoprostaglandin F 1 α and in vivo, it is rapidly metabolized by a 15-position dehydrogenase. On the other hand, PGI 2 is considered to be not entirely satisfactory in its pharmacological actions because its doses required for platelet aggregation inhibiting action and antihypertensive action are almost equal to each other and its selectivity of action as a medicine is inferior. Accordingly, a great deal of efforts have been made in the art to synthesize many kinds of PGI 2 and remedy the aforesaid defects of PGI 2 (see, for example, S. M. Roberts, Chemistry, Biochemistry & Pharamcological Activity of Prostanoids, Pergamon Press, Oxford, 1979). New Synthetic Routes to Prostaglandins and Thromboxanes, Eds S. M. Roberts and F. Scheinmann, Academic Press, 1982). Additional examples of stabilized PGI 2 structures can be found in European patent application No. 0054795A2 at page 2, which is herein incorporated by reference.
PGI derivatives and prostacyclin derivatives are well known in the art as described above. U.S. Pat. Nos. 4,123,444 and 4,124,599 described PG derivatives namely prostacyclins. These patents describe 5 and 6 keto substituents as well as 9-deoxy-9-deoxo-9-hydroxymethyl substituents. The patents are described as having general prostaglandin activity. U.S. Pat. No. 4,145,535 relates to certain trans-4, 5-didehydro-PGI compounds which are also stated to exhibit general prostacyclin like properties. U.S. Pat. No. 4,233,121 describes certain 5-halo-6,9-oxido prostaglandin derivatives which have anticoagulant activity. European patent application No. 0054795A2/1982 discloses novel 5 or 7 monohalogenated or 5,7-dihalogenated prostacyclins useful for controlling vascular actions and inhibiting tumor matastasis.
BRIEF DESCRIPTION OF THE DRAWINGS
Chart A Structure I discloses the numbering system of the allenic prostacyclin compounds of this invention. Structure II discloses the numbering system of the prostane skeleton. Structure III discloses the numbering system for prostacyclin.
Chart B Illustrates the general reaction scheme I for the synthesis of the allenic prostacyclins.
Chart C Illustrates the general reaction scheme II for synthesis of the allenic prostacyclins.
SUMMARY OF THE INVENTION
The present invention particularly provides:
A compound of the formula: ##STR2## wherein: n is 0, 1, or 2;
R 1 is hydrogen, lower alkyl, or a pharmaceutically acceptable cation;
R 2 is hydrogen, lower alkyl, cycloalkyl, heteroaryl, halogen, phenyl, alkylthio, phenylthio, alkylsulfinyl, phenylsulfinyl or trifluoromethyl;
R 3 is lower alkyl, cycloalkyl, phenyl, benzyl, cycloheteroalkyl, lower alkyl having one to eight carbons substituted with one or more fluorines or containing 1 or 2 unsaturated bonds; and
carbon 15 may be in the R or the S configuration, or a mixture of R and S.
The allenic prostacyclins of the present invention represent novel chemical structures that are chemically stable in the dry state or in solution as a sodium, potassium or calcium salt. These allenic prostacyclins present a superior therapeutic profile when compared with prostacyclin. The allenic compounds of the present invention, unlike the prior art prostacyclin compounds, unexpectedly were found not to cause an undesirable hypotensive effect when administered
Lower alkyl is a straight or a branched hydrocarbon chain having one to eight carbons. Cycloalkyl is a cyclic hydrocarbon group compound containing three to seven carbons. Cycloheteroalkyl is a cycloalkyl in which one ring carbon is replaced with one oxygen or one sulfur. Heteroaryl is an aromatic ring system having 5 or 6 ring atoms wherein one such ring atom is nitrogen, oxygen, or sulfur, and the other such ring atoms are carbons. Alkylthio is a sulfur substituted with a lower alkyl. Alkylsulfinyl is a sulfinyl function substituted with a lower alkyl. A pharmaceutically acceptable cation is cation that, when combined to form a salt with an anion such as a carboxylate function, is generally considered suitable for human consumption.
R 1 may be a lower alkyl, such as methyl, ethyl, propyl, butyl and the like. R 1 may be H or a pharmaceutically acceptable cation, such as sodium, potassium, calcium, or a quaternary alkyl ammonium ion.
R 2 may be a lower alkyl, such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl and the like. R 2 may a cycloalkyl, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and the like. R 2 may be a heteroaryl, such as pyridyl, furyl, or thienyl; a halogen such as fluorine, chlorine or bromine; phenyl; an alkylthio such as methylthio; phenylthio; an alkyl sulfinyl such as methylsulfinyl; phenylsulfinyl; or trifluoromethyl.
R 3 may be a cycloalkyl containing three to seven carbons, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and the like. R 3 may be a cycloheteroalkyl, such as tetrahydropyranyl, tetrahydrofuranyl, tetrahydrothiopyranyl and the like. R 3 may be lower alkyl containing 1 or 2 unsaturated bonds, that is, lower alkene or lower alkyne. R 3 may be lower alkene, such as ethylene, propylene, 1-butene, 2-butene, 1-pentene, 2-pentene, 3-pentene, 1-hexene, 2-hexene, 1-heptene, 2-heptene, 1-octene, 2-octene and the like. R 2 alkenes may be in either the cis or trans configuration. R 3 may be lower alkyne, such as acetylene, propyne, 1-butyne and the like, 1-pentyne and the like, 1-hexyne and the like, 1-heptyne and the like, and 1-octyne and the like, and may be optionally substituted by methyl, dimethyl or fluoro. R 3 may be a lower alkyl such as ethyl, propyl, butyl, pentyl, hexyl, heptyl or octyl and may be optionally substituted by fluoro. R 3 may also be phenyl or benzyl.
The term "carbon 15" refers to the side-chain carbon labeled as such in Chart A, structure I. To maintain consistency with usual prostanoid numbering schemes, the central allenic carbon is labeled "5a" and the term "carbon 15" is applied to the same side-chain carbon, regardless of whether n is 0, 1, or 2. Carbon 15 may have the R or S configuration or be a mixture thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
General Method
The allenic carbacyclins of this invention may be obtained as outlined in Scheme I or II or a modification thereof.
The starting material for Scheme I (I) is obtained as in P. A. Aristoff, J. Org. Chem, 46, 1954 (1981). R 3 can be adjusted as necessary (For synthesis of different R 3 s see Prostaglandin Synthesis, J. S. Bindra and R. Bindra, Academic Press 1977, p. 462)
PG 2 is a suitable protecting group, e.g. ethoxyethyl, tetrahydropyranyl or trialkylsilyl.
PG 1 is a suitable protecting group, e.g. trialkylsilyl when PG 2 =ethoxyethyl (EE) or tetrahydropyranyl (THP) or tert-butylmethoxyphenylsilyl when PG 2 =trialkylsilyl.
Treatment of this bicyclic ketone(I) with an acetylide anion of the type VII (generated from the alkyne and an appropriate base such as n-butyl lithium, see, for example, E. P. Oliveto in J. Fried and J. A. Edwards. Organic Reactions in Steroid Chemistry, Vol. II, Van Nostrand Reinhold Comp., New York 1972, p. 139) provides an intermediate alkoxide which can be quenched with water to give the propargylic carbinol (II) or trapped with a suitable electrophile, say acetic anhydride, to afford for example the propargylic acetate VIII [A propargylic sulfinate would be another possibility, see, for example, H. Westmijze, I. Nap, J. Meijer, H. Kleijn and P. Vermeer, Recl. Trav. Chim. Pays-Bas, 102, 154 (1983) and references therein.] The carbinol (II) may be treated with an electrophile such as benzenesulfenyl chloride to afford the allenic sulfoxide (III) which can be converted to the allene using a base such as methyl lithium (See, V. Van Rheenen and K. P. Shephard, J. Org. Chem., 44, 1583 (1979) and G. Neef, V. Eder and A. Seeger, Tet. Letters, 21, 903 (1980)). The protecting group on the primary hydroxyl can now be removed with a suitable fluoride source such as tetra n-butyl ammonium fluoride in tetrahydrofuran or cesium fluoride in acetonitrile or diglyme, and the alcohol converted to the corresponding acid (V, R'=H) using an appropriate oxidizing agent such as Jones reagent (8.1N) chromic acid) [For relevant literature see P. Baret, E. Barreiro, A. E. Greene, J-L. Luche, M. A. Teixeira and P. Crabbe, Tetrahedron, 35, 293 (1979)]. At this point, if an ester is required, the acid may be treated with an appropriate alkylating reagent/base combination, e.g. ethyl iodide/DBU (V, R'=Et). If a methyl ester is required, the acid may be reacted with diazomethane (V, R'=CH 3 ). If an amide is required, the acid may be condensed with an appropriate amine, e.g. dimethylamine (Me 2 NH) in the presence of a suitable dehydrating agent such as dicyclohexylcarbodiimide (V, R'=NMe 2 ) or by other well known literature procedures. The protecting group PG 2 , say THP, may be removed upon exposure to acid. Other PG 2 s may be removed by methods known in the literature (see Protective groups in Organic Chemistry, T. Greene, Wiley-Interscience, 1980). Thereby, VI can be obtained.
If a salt of the carboxylic acid is required, VI can be reacted with an appropriate base, e.g. sodium hydroxide potassium hydroxide, calcium oxide or barium hydroxide (VI, R'=Na, K, Ca, Ba).
The carbinol (II) can be utilized to access halogenated or trifluoromethylated allenes by procedures known in the literature (see, for example, The Chemistry of the Allenes, S. R. Landor Ed., Vol. I, Academic Press (1982)). For instance, a chloro-allene (IX, R 2 =Cl) can be obtained by the reaction of (II) with a chlorinating agent such as thionyl chloride in an inert solvent such as ether in the presence of a base such as pyridine or triethylamine.
Alkylated allenes or sulfur containing allenes can be accessed as shown in Scheme II. The carbinol (II) can be converted to an acetate (VIII, R=Ac) or methanesulfinate (VIII, R=CH 3 SO) as previously described.
Compounds of type VIII can be effectively converted into allenes (IX) by treatment with an appropriate organocopper reagent, e.g. dimethyl copper lithium (Me 2 CuLi, 4 equivalents, 0° C., ether) which affords R 2 =CH 3 . (For background on organocopper reagents, see G. Posner, An Introduction to Synthesis using Organocopper Reagents, Wiley-Interscience, 1980.) Thioallenes R 2 =S(Ph), SCH 3 , etc. can be accessed using VIII or another suitable intermediate using the procedure of A. J. Bridges and R. J. Ross, Tet. Letters, 24, 4797 (1983), in which a propargylic, mesylate, triflate or methanesulfinate is reacted with a organo thiocopper complex in a solvent such as methylene chloride or benzene.
The compounds of the instant invention are novel in that, compared to natural occurring PGI 2 , they are surprisingly more stable and are active against platelet aggregation over a longer period of time.
By virtue of this anti-platelet aggregation activity the compounds of formula I are useful in treating platelet dysfunction in human and animals. A physician or veterinarian of ordinary skills could readily determine a subject who is exhibiting platelet dysfunction symptoms. Regardless of the route of administration selected, the compounds of the present invention are formulated into pharmaceutically acceptable dosage forms by conventional methods known to the pharmaceutical arts.
The compounds can be administered in such oral unit dosage forms such as tablets, capsules, pills, powders, or granules. They also may be administered rectally, vaginally in such forms as suppositories or creams; they may also be introduced in the form of eye drops, parenterally, subcutaneously, or intramuscularly, using forms known to the pharmaceutical art. In general, the preferred form of administration is orally.
An effective but non-toxic quantity of the compound is employed in treatment. The dosage regimen for preventing or treating platelet dysfunction by the compounds of this invention is selected in accordance with a variety of factors including the type, age, weight, sex, and medical condition of the mammal, the severity of the symptoms, the route of administration and the particular compound employed. An ordinarily skilled physician or veterinarian will readily determine and prescribe the effective amount of the agent to prevent or arrest the progress of the condition. In so proceeding, the physician or veterinarian could employ relatively low dosages at first, subsequently increasing the dose until a maximum response is obtained.
The acidic compounds of this invention can also be administered as pharmacologically acceptable basic salts such as sodium, potassium and calcium.
EXPERIMENTAL SECTION
1 H and 13 C NMR spectra were recorded on a Varian FT80 or XL200 spectrometer at 80 or 200 MHz (for 1 H) and 50.3 MHz (for 13 C) with chemical shifts reported in parts per million (δ) downfield from tetramethylsilane as an internal standard. Splitting patterns are designated as s, singlet; d, doublet; t, triplet; q, quartet; and m, multiplet
Infrared spectra (IR) were obtained as solution in chloroform (CHCl 3 ) and are given in cm -1 . (Only major frequencies are recorded.) Mass Spectra were run on a Kratos MS30 or MS50 at 70 eV and an ionizing current of 300 mA.
Elemental analyses were performed by the microanalytical department at G. D. Searle & Co.
EXAMPLE 1
5-Hexyn-1-ol t-butyldimethylsilyl ether (2) ##STR3##
5-Hexyn-1-ol(9.8 g, 0.1 Mol) was dissolved in dry DMF (25 cm 3 ) containing Imidazole (13.6 g, 0.2 Mol) and tert-butyldimethylsilyl chloride (18.0 g, 20.1 Mol). The mixture was stirred at 25° C. under nitrogen for 10 hours and then poured into water (50 cm 3 ). The aqueous material was thoroughly extracted with hexane (4×100 cm 3 ) and the combined organic extracts washed with water (100 cm 3 ) and brine (100 cm 3 ). Evaporation of dried (Na 2 SO 4 ) solvent in vacuo afforded 20.2 g of crude product, which was distilled under reduced pressure (1.5 mmHg) b.p 65° C. to afford 16.1 g of pure silyl-ether.
Analytical data
NMR ( 1 H,δ, CDCl 3 , 80 MHz) 3.6 (2H,t,--CH 2 OSit-BuMe 2 )
IR (CHCl 3 ) 3300 cm -1 (C.tbd.C)
Microanalysis:Found: C, 67.72, H, 11.79. Calc: C, 67.79, H, 11.30.
EXAMPLE 2
(3aβ,6aβ)-4β-[3R*-cyclopentyl-3-[(tetrahydro-2H-pyran-2-yl)oxy]-1E-propenyl]-2-[6-[[(1,1-dimethylethyl)dimethylsilyl]oxy]-1-hexynyl]octahydro-5α-[(tetrahydro-2H-pyran-2-yl)oxy]-2S,2α-pentalenol, acetate, and,
(3aα,6aα)-4α-[3S*-cyclopentyl-3-[(tetrahydro-2H-pyran-2-yl)oxy]-1E-propenyl]-2-[6-[[(1,1-dimethylethyl)dimethylsilyl]oxy]-1-hexynyl]octahydro-5β-[(tetrahydro-2H-pyran-2-yl)oxy]-2R,2α-pentalenol, acetate. ##STR4##
Compound (2) (1.05 g) was dissolved in dry THF (15 cm 3 ) and cooled to -25° C. (argon, mag. stirring). A solution of n-Butyllithium in hexane (1.63 M, 3.0 cm 3 ) was added via syringe and the mixture stirred at -25° C. for 1 hour. At this point, Compound (3) was added as a solution in THF and the mixture stirred for 1 hour at 0° C. Ac 2 O (1 cm 3 ) was added via syringe and the mixture stirred at 0° C. for 30 minutes and then at 25° C. for 30 minutes. The mixture was partitioned between ether and sodium bicarbonate. The organic layer was separated, washed with brine and dried (Na 2 SO 4 ). Evaporation of the volatiles in vacuo afforded 2.1g of crude product. Purification by chromatography on silica gel (Merck 60, ethylace tate/hexane 20:80) afforded 3.1g of propargylic acetates.
NMR ( 1 H,δ,CDCl 3 , 80 MHz) 0.2 (6H,s,(CH 3 ) 2 Si--), 0.9 (9H,s,(CH 3 )C--Si--), 2.1 (3H,s,OAc) 1.25-2.5 (40H,m,cycloalkyl Hs and α chain Hs), 3.25-4.0 (8H,m,THPH's α to 0, +CH--O Hs 4.6 (2H,m,THP anomeric Hs), 5.25-5.75 (2H,m,olefinic Hs)
Ir (CHCl 3 ) 2210, 1745, 1250 cm -1 . 0.35 g of propargylic alcohols (5)
NM,R ( 1 H,δ,CDCl 3 , 80 MHz), 0.2 (6H, s, (CH 3 ) 2 Si--), 0.9 (9H, s, (CH 3 )C--Si) 1.25-2.5 (40H, m, cycloalkyl Hs and α-chain Hs), 3.25-4.0 (8H, m, THP Hs α to 0, +CH-OHs), 4.6 (2H, m, THP anomeric Hs), 5.25-5.75 (2H, m, olefinic Hs)
The structure and names of the products are:
(3aβ, 6aβ)-4β-[3R*-cyclopentyl-3-[(tetrahydro-2H-pyran-2-yl)oxy]-1E-propenyl]-2-[6-[[(1,1-dimethylethyl)dimethylsilyl]oxy]-1-hexynyl]octahydro-5.alpha.-[(tetrahydro-2H-pyran-2-yl)oxy]-2S,2α-pentalenol, acetate, and
(3aα,6aα)-4α-[3S*-cyclopentyl-3-[(tetrahydro-2H-pyran-2-yl)oxy]-1E-propenyl]-2-[6-[[(1,1-dimethylethyl)dimethylsilyl]oxy]-1-hexynyl]octahydro-5β-[(tetrahydro-2H-pyran-2-yl)oxy]-2R,2α-pentalenol. ##STR5##
EXAMPLE 3
(3aα, 6aα)-2-[[1S*-cyclopentyl-3-[5-[6[[(1,1-dimethylethyl)dimethylsilyl]oxy]-2S*-(phenylsulfinyl)-1-hexenyliden]octahydro-2β-[(tetrahydro-2H-pyran-2-yl)oxy]-1R, 1α-pentalenyl]-2E-propenyl]oxy]tetrahydro-2H-pyran, and,
(3aα, 6aα)-2-[1S*-cyclopentyl-3-[5-[6-[[(1,1-dimethylethyl)dimethylsilyl]oxy]-2R*-(phenylsulfinyl)-1-hexenylidene]octahydro-2β-[(tetrahydro-2H-pyran-2-yl)oxy]-1R, 1α-pentalenyl]-2E-propenyl]oxy]tetrahydro-2H-pyran. ##STR6##
Compound (5) (0.39 g, 0.6 mMol) was dissolved in CH 2 CH 2 (10 cm 3 ) containing triethylamine (2.5 equivalents) and the mixture cooled to -70° C. A solution of benzenesulfenyl chloride (30.1 g, 1.5 equiv) was added dropwise over a period of 10 mins (mag. stirring, argon). The mixture was stirred at -70° C. for 1 hour and then warmed to -20° C. Stirring was continued at -20° C. for a further hour and the mixture was then poured into 2N NaHCO 3 /CH 2 Cl 2 . The organic layer was separated and washed with brine; evaporation of the volatiles in vacuo afforded 410 mgs of crude product which was purified by chromatography on Merck 60 (ethyl acetate/hexane, 2:8) to afford 311 mgs of allene sulfoxides (6).
NMR ( 1 H,δ, CDCl 3 , 80 MHz) 0.2 (6H, m, --Si(CH 3 ) 2 ), 0.9(9H,d,Sit-Bu), 1.25-2.6 (40H, m, cycloalkyl Hs and α-chain Hs), 3.3-4.0 (8, Hm, THPHs α to 0+CH--O Hs), 4.65 (2H, m, THP anomeric Hs), 5.25-5.75 (2H, m, olefinic Hs), 7.5 (5H, m. aromatic Hs)
Ir (CHCl 3 ) 1250, 1080, 1030, 1020 cm -1
EXAMPLE 4
(3aα,6aα)-2-[[1S*-cyclopentyl-3-[5R*-[6-[[(1,1 -dimethylethyl)dimethylsilyl ]oxy]-1-hexenylidene]octahydro-2-[(tetrahydro-2H-pyran-2-yl)oxy]-1R,1.alpha.-pentalenyl]-2E-propenyl]oxy]tetrahydro-2H-pyran, and,
(3aα,6aα)-2-[[1S*-cyclopentyl-3-[5S*-[6-[[(1,1-dimethylethyl)dimethylsilyl]oxy]-1-hexenylidene]octahydro-2-[(tetrahydro-2H-pyran-2-yl)oxy]-1R,1α-pentalenyl]-2E-propenyl]oxy]tetrahydro-2H-pyran ##STR7##
Compound (6) (0.311 g, 0.41lmMol) was dissolved in dry THF (10 cm 3 ) (-70° C., argon, stirring) and methyllithium (1.2M in Et 2 O, 1.4 cm 3 , 4 equiv) added via a syringe. The mixture was stirred at -70° C. for 15 minutes and then quenched with ammonium chloride solution. The cold mixture was thoroughly extracted with ether and the combined organic extracts washed with brine and dried (Na 2 SO 4 ). Evaporation of the volatiles in vacuo afforded 0.25 g of crude product. Chromatography on Merck 60 silica gel (10% ethyl acetate/hexane) afforded 170 mgs of pure allene sulfoxides 7(69%).
NMR ( 1 H,δ, CDCl 3 , 80 MHz) 0.2 (6H, m, --Si(CH 3 ) 2 ), 0.9(9H,d,Sit-Bu) 1.25-2.6 (40H, m, cycloalkyl Hs and α-chain Hs), 3.3-4.0 (8H, m, THP Hs α to 0+CH--O Hs) 4.65 (2H, m, THP anomeric Hs), 5.05 (1H, m, allene H) 5.25-5.75 (2H, m, olefinic Hs)
Ir (CHCl 3 ) 1250, 1110, 1045, 1020 cm -1 .
EXAMPLE 5
(3aS,3aα,6aα)-6-[4α-[3R*-cyclopentyl-3-[(tetrahydro-2H-pyran-2-yl)oxy]-1E-propenyl]hexahydro-5β-[(tetrahydro-2H-pyran- 2-yl)oxy]-2(1H)-pentalenylidene]-5S*-hexen-1-ol, and,
(3aS,3aα,6aα)-6-[4α-[3R*-cyclopentyl-3-[(tetrahydro-2H-pyran-2-yl)oxy]-1E-propenyl]hexahydro-5β-[(tetrahydro-2H-pyran-2-yl)oxy]-2(1H)-pentalenylidene]-5R*-hexen-l-ol. ##STR8##
Compound (7) (0.35 g, 0.59 mMol) was dissolved in anhydrous THF (10 cm 3 ) and a solution of tetrabutylammonium fluoride in THF (1M, 2cm 3 , xs) was added via syringe. The mixture was stirred at 25° C. for 10 hours (argon) and then partitioned between ether and 2N NaHCO 3 . The organic layer was separated and the aqueous layer thoroughly extracted with ether. The combined organic extracts were washed with brine, dried (Na 2 SO 4 ) and evaporated in vacuo. The crude product was purified by chromatography on silica gel (Merck 60, EA/hexane 35:65) to afford 0.17 g of alcohol.
NMR ( 1 H, δ, CDCl 3 , 200 MHz) 1.2-2.65 (40 H, m cycloalkyl Hs and α-chain Hs), 3.3-4.0 (8H, m, THP Hs α to 0+CH--O Hs), 4.65 (2H, m, THP anomeric Hs), 5.1 (1H, m, allene H), 5.25-5.75 (2H, m, olefinic Hs)
Ir (CHCl 3 ) 3450-3500 cm -1
EXAMPLE 6
methyl (3aS,3aα,6aα)-6-[4α-[3R*-cyclopentyl-3-[(tetrahydro-2H-pyran-2-yl)oxy]-1E-propenyl]hexahydro-5β-[(tetrahydro-2H-pyran-2-yl)oxy]-2(1H)-pentalenylidene]-5S*-hexenoate, and,
methyl (3aS,3aα,6aα)-6-[4α-[3S*-cyclopentyl-3-[(tetrahydro-2H-pyran-2-yl)oxy]-1E-propenyl]hexahydro-5β-[(tetrahydro-2H-pyran-2-yl)oxy]-2(1H)-pentalenylidene]-5R*-hexenoate. ##STR9##
Compound (8) (0.12 g, 0.2 mMol) was dissolved in distilled (acetone (10 cm 3 ) at -25° C. Jones reagent (0.21 cm 3 ) was added dropwise via a syringe. The mixture was stirred at -20° C. for 2 hours and then quenched with isopropanol (1 cm 3 ). The mixture was partitioned between EtOAc and brine; the organic layer was separated and the aqueous layer thoroughly extracted with more EtOAc. The combined organic extracts were dried (Na 2 SO 4 ) and evaporated in vacuo. The crude gum thus obtained was treated with excess diazomethane in ether and evaporated under nitrogen. The product was purified by chromatography on Merck silica gel 60 (hexane/EA 9:1) to afford 75 mgs of ester.
NMR ( 1 H, δ, CDCl 3 , 200 MHz) 1.2-2.65 (40 H, m, cycloalkyl Hs and α-chain Hs), 3.3-4.0 (6H, m, THP Hs α to 0+CH--O Hs) 3.7 (3H, s, CO 2 CH 3 ) 4.65 (2H, m, THP anomeric Hs), 5.1 (1H, m, allene H), 5.25-5.75 (2H, m, olefinic Hs)
Ir (CHCl 3 ) 1730 cm -1
EXAMPLE 7
methyl (3aS,3aα,6aα)-6-[4α-(3R*-cyclopentyl-3-hydroxy-1E-propenyl)hexahydro-5β-hydroxy-2(1H)-pentalenylidene]-5S*-hexenoate, and,
methyl (3aS,3aα,6aα)-6-[4α-(3R*-cyclopentyl-3-hydroxy-1E-propenyl)hexahydro-5α-hydroxy-2(1H)-pentalenylidene]-5R*-hexenoate ##STR10##
Compound (9) (75 mg) was dissolved in a mixture of acetic acid, THF and water (5 cm 3 , 3:1:1) and stirred under argon at 25° C. for 24 hrs. At this point, the reaction was neutralized with solid K 2 CO 3 and partitioned between EtOAc and water. The organic layer was separated and the aqueous layer thoroughly extracted with more EtOAc. The combined organic extracts were dried (Na 2 SO 4 ) and evaporated in vacuo to afford 60 mgs of crude product. Careful chromatography on silica gel (Merck 60, EA/hexane 55:45) afforded 52 mgs of α-H allene and 4 mgs of β-H allene.
NMR ( 1 H, δ, CDCl 3 , 200 MHz) 1.2-2.6 (24H, m, cycloalkyl and α-chain H's), 2.9 (2H, broad, OH), 3.65 (3H, s, CO 2 CH 3 ), 3.65-3.85 (2H, m, CH--0 Hs), 5.1 (1H, m, allene H), 5.5 (2H, m, olefinic Hs) ( 13 C, δ, CDCl 3 50.3 MHz) ##STR11##
IR (CHCl 3 ) 3500 (broad), 1730 cm -1
Microanalysis: C 23 H 34 O 4 requires C:73.76, H:9.15; Found C:73.4, H:9.03.
EXAMPLE 8
(3aS,3aα,6aα)-6-[4α-(3R*-cyclopentyl-3-hydroxy-1E-propenyl)hexahydro-5β-hydroxy-2(1H)-pentalenylidene]-(5S*)-hexenoic acid sodium salt ##STR12##
Compound (10) (40 mgs) was dissolved in methanol (0.5 cm 3 ) and 1.1 equivalents of a 1N solution of sodium hydroxide in water were added via syringe. The mixture was stirred under argon at 25° C. for 10 hours and then evaporated in vacuo to afford 42 mgs of sodium salt (11).
EXAMPLE 9
(3aα, 6aα)-2-[[1S*-cyclopentyl-3-[5-[6-[[(1,1-dimethylethyl) dimethylsilyl]oxy]-2R*-methyl-1-hexenylidene]octahydro-2β-[(tetrahydro-2H-pyran-2-yl)oxy]-1R,1α-pentalenyl]-2E-propenyl]oxy]tetrahydro-2H-pyran, and
(3aα,6aα)-2-[[1S*-cyclopentyl-3-[5-[6-[[(1,1-dimethylethyl) dimethylsilyl]oxy]-2S*-methyl-1-hexenylidene]octahydro-2β[(tetrahydro-2H-pyran-2-yl)oxy]-1R,1α-pentalenyl]-2E-propenyl]oxy]tetrahydro-2H-pyran ##STR13##
Compound (4) (0.634 g, 0.92 mMol) in dry Et 2 O (2 cm 3 ) was added via syringe to a solution of lithium dimethylcuprate (4 equivalents) in ether at -20° C. (Mag. stirring, argon). The reaction mixture was stirred at 0.5° C. for 2 hours and then quenched with NH 4 Cl solution. The mixture was thoroughly extracted with ether and the combined extracts were washed with water, brine and then dried (Na 2 SO 4 ). Evaporation of the volatiles in vacuo afforded 0.61 g of crude product which was purified by chromatography on silica gel (Merck 60, 10% EA/hexane) to afford 0.578 g of allenes (97%)
NMR ( 1 H, δ, CDCl 3 , 80 MHz) 0.2 (6H, m, --Si(CH 3 ) 2 ), 0.9(9H,d,Sit-Bu)1.25-2.6 (40H, m, cycloalkyl Hs and α-chain Hs), 1.85 (3H, s, allenic CH 3 ), 3.3-4.0 (8H, m, THPHs α to 0+CH--0 Hs), 4.65 (2H, m, THP anomeric Hs), 5.25-5.75 (2H, m, olefinic Hs) ( 13 C, δCDCl 3 , 50.3 MHz) ##STR14##
Ir (CHCl 3 ) 1250, 1110, 1072, 1030, 1020 cm -1
EXAMPLE 10
(3aS,3aα,6aα)-6-[4α-[3R*-cyclopentyl-3-[(tetrahydro-2H-pyran-2-yl)oxy]-1E-propenyl]hexahydro-5β-[tetrahydro-2H-pyran- 2-yl)oxy]-2(1H)-pentalenylidene]-5S*-methyl-5-hexen-1-ol, and,
(3aS,3aα,6aα)-6-[4α-[3R*-cyclopentyl-3-[(tetrahydro-2H-pyran-2-yl)oxy]-1E-propenyl]hexahydro-5β[(tetrahydro-2H-pyran-2-yl)oxy]-2(1H)-pentalenylidene]-5R*-mehtyl-5-hexen-1-ol. ##STR15##
Compound (12) (0.538 g, 0.8 mMol) was treated with an excess of n-Bu 4 NF (1M in THF) as in Example 5. Chromatography on silica gel (Merck 60, 25% EA/hexane) afforded 0.48 g of alcohol.
NMR ( 1 H, δ, CDCl 3 , 80MHz) 1.25-2.6 (40 H, m, cycloalkyl Hs and α-chain Hs) 1.65 (3H, s, allenic CH 3 ), 3.3-4.0(8H, m, THP Hs α to O+CH--O Hs), 4.65 (2H, m, THP anomeric Hs), 5.25-5.75 (2H, m, olefinic Hs)
Ir (CHCl 3 ) 3500-3600 cm -1 (ν-OH)
EXAMPLE 11
methyl (3aS,3aα,6aα)-6-[4α-[3R*-cyclopentyl-3-[(tetrahydro-2H-pyran-2-yl)oxy]-1E-propenyl]hexahydro-5β-[(tetrahydro-2H-pyran-2-yl)oxy]-2(1H)-pentalenylidene]-5S*-methyl-5-hexenoate, and,
methyl (3aS,3aα,6aα)-6-[4α-[3R*-cyclopentyl-3-[(tetrahydro-2H-pyran-2-yl)oxy]-1E-propenyl]hexahydro-5-β-[(tetrahydro-2H-pyran-2-yl)oxy]-2(1H)-pentalenylidene]-5R*-methyl-5-hexenoate. ##STR16##
Compound (13) (0.39 g, 0.7395 mMol) was oxidized with Jones reagent in acetone at -20° C. as in Example 6. After treatment of the crude acid with CH 2 N 2 , the residue was purified by chromatography on silica gel (Merck 60, hexane/10% EA) to afford 280 mgs of ester.
NMR ( 1 H, δ, CDCl 3 , 80 MHz) mixture of allene isomers 1.2-2.65 (40 H, m, cycloalkyl Hs and α-chain Hs), 1.65 and 1.70 (3H, 2 singlets, allene methyls), 3.3-4.0 (SH, m, THPHs α to O+CH--O Hs), 3.65 and 3.70 (3H, two singlets, CO 2 CH 3 ) 4.65 (2H, m, THP anomeric Hs), 5.25-5.75 (2H, m, olefinic Hs).
Ir (CHCl 3 ) 1730 cm -1
EXAMPLE 12
methyl (3aS,3aα,6aα)-6-[4α-(3R*-cyclopentyl-3-hydroxy-1E-propenyl)hexahydro-5β-hydroxy-2(1H)-pentalenylidene-5S*-methyl-5-hexenoate, and,
methyl (3aS,3aα,6aα)-6-[4α-(3R*-cyclopentyl-3-hydroxy-1E-propenyl)hexahydro-5β-hydroxy-2(1H)-pentalenylidene]-5R*-methyl-5-hexenoate ##STR17##
Compound (14) (0.22 g, 0.39 mMol) was treated with AcoH/THF/H 2 O (15 cm 3 , 3:1:1) as in Example VIII. After chromatography on Merck 60 (EA/hexane 6:4) 100 mgs of β-methyl allene was obtained plus 15 mgs of α-methyl allene (slightly higher Rf) (71%).
NMR ( 1 H, δ, CDCl 3 , 80 MHz) 1.2-2.6 (24H, m, cycloalkyl and α-chain Hs), 1.65 (3H, s, allene CH 3 ), 3.65 (3H, s, CO 2 CH 3 ), 3.65-3.85 (2H, m, CH--O Hs), 5.5 (2H, m, olefinic Hs), 1.2-2.6 (24H, m, cycloalkyl and α-chain Hs), 1.7 (3H, s, allene CH 3 ), 3.70 (3H, s, CO 2 CH 3 ), 3.65-3.85 (2H, m, CH--O Hs), 5.5 (2H, m, olefinic Hs) ( 13 C, δ, CDCl 3 , 50.3 MHz) ##STR18##
Ir (CHCl 3 ) 3500-3400, 1730 cm -1
High Resolution M.S. M+--H 2 O, Found for C 24 H 34 O 3 370.2501; Deviation from calculated M+--H 2 O=-2.0 ppm. M+--(H 2 O) 2 , Found for C 24 H 32 O 2 352.2398; Deviation from calculated M+--(H 2 O) 2 =-1.4 ppm.
EXMAPLE 13
(3aS,3aα,6aα)-6-[4α-(3R*-cyclopentyl-3-hydroxy-1E-propenyl)hexahydro-5β-hydroxy-2(1H)-pentalenylidene]-5R*-methyl-5-hexenoic acid, sodium salt ##STR19##
Compound (15) (0.115 g, 0.28 mMol) was saponified in the manner described previously in Example 8. Thus obtained were 120 mgs of a cream-white amorphous solid compound (16).
EXMAPLE 14
(3aα,6aα)-2-[3-[5-[2R*-chloro-6-[[(1,1-dimethylethyl) dimethylsilyl)oxy]-1-hexenylidene]-1R,1α-[3S*-cyclopentyl-3-[(tetrahydro-2H-pyran-2-yl)oxy]-1E-propenyl]octahydro-2β-pentalenyl]oxy]tetrahydro-2H-pyran, and,
(3aα,6aα)-2-[3-[5-[2S*-chloro-6-[[(1,1-dimethylethyl) dimethylsilyl]oxy]-1-hexenylidene]-1R,1-[3S*-cyclopentyl-3[(tetrahydro-2H-pyran-2-yl)oxy]-1E-propenyl]octahydro-2αpentalenyl]oxy]tetrahydro-2H-pyran ##STR20##
Compound (5) (0.39 g, 0.6 mMol) was dissolved in dry ether (10 cm 3 ) containing triethylamine (1.5 equivalents) and the mixture cooled to -20° C. Thionyl chloride (1.0 equivalents) was added via a syringe and the mixture stirred at 0° C. until all starting material had been consumed. The mixture was partitioned between sodium bicarbonate and ether. The organic layer was separated, dried (Na 2 SO 4 ) and evaporated in vacuo to afford the crude product which could be purified by chromatography on silica gel (Merck 60).
EXMAPLE 15
(3aα,6aα)-2-[[1S*-cyclopentyl-3-[5-[6-[[(1,1-dimethylethyl) dimethylsilyl]oxy]-2-(phenylthio)-1-hexenylidene]octahydro-2-β[(tetrahydro-2H-pyran-2-yl)oxy]-1R,1α-pentalenyl]-2E-propenyl]oxy]tetrahydro-2H-pyran ##STR21##
Mesylate (18) (prepared in situ by the Method of Crossland and Servis, J. Org. Chem., 35, 3195 (1970) was treated as a solution in CH 2 Cl 2 at 0° C. with one equivalent of phenylthiocopper-trimethylphosphite complex. The mixture was stirred at room temperature overnight and then partitioned between ether and cold dilute hydrochloric acid. The suspension was filtered under vacuum and the organic layer washed with water and brine and then dried (Na 2 SO 4 ). Chromatography of the crude product provided pure (19).
BIOLOGICAL TESTING
The Inhibition of ADP-Induced Platelet Aggregation
The procedure for testing platelet anti-aggregatory activity in vitro is the following one described by E. R. Waskawic. Aggregation was determined with a Payton Dual Channel Aggregation module. A Riken-Denshi recorder was used for recording the aggregation curves.
Citrated whole blood (1 part 3.8% sodium citrate and 9 parts blood) was centrifuged to obtain platelet rich plasma (PRP) (700 RPM for 11 mins.) in an IE centrifuge (Model PR 6000). After the PRP fraction was removed, the remainder was spun at 900 ×g for 15 mins. to obtain platelet poor plasma (PPP) (1800 RPM in IEC PR 6000). The number of platelets per ml PRP is determined by counting a 5 μl aliquot of PRP in a Coutter ZBI counter and channelyzer Model C-1000.
PRP is diluted with PPP 1:2 to obtain a count of approx. 25000 on the screen or 10 9 platelets/ml PRP to evaluate the anti-aggregating agent. The module was standardized with an aliquot of PPP and that of diluted PRP.
The aggregating agent used is ADP prepared as follows:
4.7 mgs ADP (MW 427) in 10 ml saline yields a 10 μL PRP, of ADP disodium (MW=473).
______________________________________Vol. of stock (ml) Volume of saline (ml) [f] cuvette (μM)______________________________________1.6 0.4 81.2 0.8 60.8 1.2 40.4 1.6 20.2 1.8 1______________________________________ [f] = final concentration
Prostacyclin is used as the standard of antiaggregatory activity for determining the potency of compounds tested. A 10 2 M solution (to give a starting concentration of 10 -4 M when 4 μL is added to 400 μL PRP) is diluted serially to obtain solutions with final concentrations of 10 -6 , 10 -7 , 10 -8 , 10 -9 M.
Compounds to be screened are dissolved in absolute ethanol, saline or water to achieve a 10 -2 M solution if 4 μL added to PRP giving a [f] in the cuvette equal to 10 -4 M. Serial dilutions in saline give 10 -5 , 10 -6 and 10 -7 M.
1. Determine the dose of ADP which on a standard curve would be on the linear portion and allow reversal of the aggregation curve.
2. Determine the PGI 2 standard curve of percentage inhibition of aggregation. Use saline in control cuvette to compare the extent of inhibition by PGI 2 as represented by the depth of the aggregation curve. Allow the PRP to preincubate for approximately one minute prior to the addition of prostacyclin and another minute with PGI 2 prior to the addition of ADP. ##EQU1##
The % inhibition is plotted against prostacyclin dose on semilog paper. The IC 50 value is equal to the PGI 2 dose effecting 50% inhibition of the control response.
3. The test compound is added to PRP and preincubated for 1 minute prior to ADP administration. If the compound has an IC 50 less than 10 -4 M, it is considered to be active.
Hypotensive Activity in the Hexamethonium Treated Rat
Animals are anesthetized with barbital (100 mg kg) and pentobarbital (25 mg/kg). A tracheotomy tube is inserted and animals are allowed to breathe 100% O 2 spontaneously. Jugular and carotid cannulae are implanted (for drug administration and pressure measurement, respectively). Animals are maintained at 37° C. body temperature. Rats are then dosed with 1 mg/kg hexamethonium, i.v. bolus. Steady-state levels are allowed to be reached in 5 min. and animals are dosed with drug. All compounds are dissolved in either dimethyl sulfoxide or aqueous ethanol or glycine buffer (pH ˜10), and in a volume of 1 ml/kg. Approximate ED 50 doses are administered and changes in mean arterial pressure are recorded every 30 sec. for 5 min. Surprisingly, the tested compounds, while active in the inhibition of ADP induced platelet aggregation, did not exhibit the hypotensive effect exhibited by the prostacyclins.
__________________________________________________________________________BIOLOGICAL TESTING OF SELECT EXAMPLES In Vitro Inhibition of ADP InducedCompound Platelet Aggregation Hypotensive Effect__________________________________________________________________________Example 7 ##STR22## 1 × 10.sup.-6 M None up to 100 mg/kgExample 8 ##STR23## 4 × 10.sup.-6 M None up to 100 mg/kgExample 12 ##STR24## 1.3 × 10.sup.-5 M None up to 100 mg/kgExample 12 ##STR25## 1.0 × 10.sup.-6 M None up to 100 mg/kgExample 13 ##STR26## 2.1 × 10.sup.-7 M None up to 100 mg/kgExample 13 ##STR27## 1 × 10.sup.-5 M None up to 100 mg/kg__________________________________________________________________________
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The present invention describes allenic prostacyclin derivatives of the formula: ##STR1## wherein: n is 0, 1, or 2;
R 1 is hydrogen, lower alkyl, or a pharmaceutically acceptable cation;
R 2 is hydrogen, lower alkyl, cycloalkyl, heteroaryl, halogen, phenyl, alkylthio, phenylthio, alkylsulfinyl, phenylsulfinyl or trifluoromethyl;
R 3 is lower alkyl, cycloalkyl, phenyl, benzyl, cycloheteroalkyl, lower alkyl having one to eight carbons substituted with one or more fluorines or containing 1 or 2 unsaturated bonds; and
carbon 15 may be in the R or the S configuration, or a mixture of R and S.
These compounds are useful for the treatment of platelet dysfunction, atherosclerosis, allergic disorders, gastric ulcers, hypertension and tumor cell metastasis. Also disclosed is the process for preparing them and the appropriate intermediates.
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BACKGROUND TO THE INVENTION
The present invention relates, in general terms, to torsion-damping devices comprising at least two coaxial parts mounted rotatably relative to one another within the limits of a specific angular movement and against the action of elastic means designed to act circumferentially between them, referred to below for the sake of convenience as elastic means with circumferential action.
As is known, such a torsion-damping device is conventionally employed in a clutch plate assembly, especially for a motor vehicle, in which case one of its rotary parts comprises a friction disc intended to be fixed in rotation to a first shaft, in practice a drive shaft, for example the output shaft of the engine in the case of a motor vehicle, whilst another of the said rotary parts is carried by a hub intended to be fixed in rotation to a second shaft, in practice a driven shaft, for example the input shaft of a gearbox in the case of such a motor vehicle.
Such a torsion-damping device makes it possible to ensure controlled transmission of the torque applied to one of its rotary parts when the other is itself subjected to a torque, that is to say to filter the vibrations liable to arise over the entire length of the kinematic chain which extends from the engine to the controlled wheel shafts in the case of a motor vehicle.
The elastic means with circumferential action usually consist of springs of the helical-spring type which extend substantially tangentially to a circumference of the assembly and which, each individually, are arranged partly in a receptacle provided for this purpose in one of the rotary parts in question and partly in a receptacle likewise provided for this purpose in the other of the said rotary parts.
Also, more often than not, these elastic means with circumferential action are distributed in what is commonly called several "stages" which are of different rigidities and the intervention of which is adjusted as a function of the angular movement between the two rotary parts in question; only a first of these stages of relatively low rigidity intervenes at the start of this movement, and, in proportion to the development of the latter, one or more other stages of relatively higher rigidity subsequently add their own effects to those of the first.
In practice, for each of the springs of the stages of relatively high rigidity, the intervention of which is to be delayed in this way, a certain play is provided circumferentially for this purpose between the end edge of the receptacle, in which such a spring is located in one of the rotary parts in question, and the corresponding end edge of the receptacle in which it is located in the other of the said rotary parts.
In a given embodiment, this play is not necessarily the same for both directions of change in the angular movement between the rotary parts in question; it can, for example, be greater for that direction of change which corresponds to operation of the assembly in "traction", and is consequently less for that direction which corresponds to the operation of the latter "on the overrun".
Likewise, for a given total play, the relative values of this play for both of the directions of change in the angular movement are not necessarily the same for all the practical embodiments liable to arise.
The present invention is intended more particularly for the case where, in addition to the springs used in this way, the elastic means with circumferential action, interposed between the two rotary parts in question, incorporate at least one elastically deformable arm which, extending between two bearing elements, one designed to be fixed in rotation in a positive way to one of the said rotary parts and the other being provided with drive means designed to connect it in rotation to the other of the said rotary parts over at least one range of the angular movement between these, is cut out in one piece with the said bearing elements from a blank of small thickness.
Such an arrangement, which can advantageously make it possible to minimise the number of receptacles to be provided for springs in the two rotary parts in question, is described particularly in the French Patent filed on 3rd Nov. 1980 under No. 80/23,447 and published under No. 2,493,446, in which, in practice, the elastically deformable arm or arms used in this way constitute the first stage of relatively low rigidity of the corresponding elastic means circumferential action, instead of springs.
In this French Patent, pins or the like are provided more particularly for fixing one of the bearing elements of such an elastically deformable arm positively to one of the rotary parts in question.
Although such an arrangement is satisfactory, it has disadvantages, especially in that it is necessary to make perforations for installing such pins.
The subject of the present invention is, in general terms, an arrangement making it possible to avoid this disadvantage and resulting in other advantages.
SUMMARY
More specifically, its subject is a torsion-damping device, particularly a clutch plate assembly, of the type comprising at least two coaxial parts mounted rotatably relative to one another within the limits of a specific angular movement and counter to elastic means designed to act circumferentially between the said parts, called elastic means with circumferential action, the said elastic means with circumferential action incorporating at least one elastically deformable arm which, extending between two bearing elements, one designed to be fixed in rotation in a positive way to one of the said rotary parts and the other being provided with drive means designed to connect it in rotation to the other of the said rotary parts over at least one range of the angular movement between these, is cut out in one piece with the said bearing elements from a blank of small thickness, this torsion-damping device being characterised in that the said bearing element which is fixed in rotation in a positive way to one of the rotary parts incorporates, projecting radially from it, at least two barbs which are forceably engaged axially in a bearing surface of the said rotary part and between which the said bearing element is elastically deformable radially and circumferentially.
In practice, the bearing element in question incorporates, distributed circularly, a plurality of barbs, but in limited numbers, for example three.
At all events, when they engage in the relevant bearing surface of one of the rotary parts in question, these barbs machine axially on the surface of the latter furrows or grooves as a result of the upsetting of material, and the capacity for elastic deformation which the bearing element carrying them possesses radially and circumferentially makes it possible advantageously to mitigate the consequences of the unavoidable production tolerances between such a bearing element and such a rotary part and/or to compensate the plays which inevitably arise during operation between the barbs of this bearing element and the furrows or grooves machined by them.
This compensates for the fact that because of construction these barbs are cut out from a blank of relatively reduced thickness.
Of course, it is already known, particularly from the French Patent filed on Dec. 28th 1973 under No. 73/46,897 and published under U.S. Pat. No. 2,256,686, to join together two concentric components by providing on one of them teeth which, when it is fitted onto the other, machine furrows in the surface of the latter.
However, apart from the fact that, in this French Patent, such an arrangement is used for fastening to a hub not an element bearing an elastically deformable arm of small thickness, but a simple relatively thick disc, the teeth which this disc thus possesses are contiguous, immediately following one another circularly, so that there is a relatively large number of them and so that between such teeth disc does not possess any particular capacity for elastic deformation radially and/or circumferentially.
The reason for this is, in particular, that during operation a relatively high torque must pass from the disc to the hub via these teeth.
The same does not apply in this case to the elastically deformable arm or arms of the bearing element in question, belonging to a stage of relatively low rigidity of the elastic means with circumferential action, so that the torque to be transmitted by means of this stage, and therefore the torque which, via the barbs of this bearing element, must pass from the latter to the rotary part in question, is always relatively low.
It is for the very reason that the torque to be transmitted is therefore relatively low that the arrangement according to the invention can be envisaged in combination with, on the one hand, a reduction in the number of teeth or barbs used and, on the other hand, the joint development of a capacity for radial and circumferential deformation in the relevant bearing element between two of these teeth or barbs.
However, the arrangement according to the invention also results in other advantages.
First of all, it makes it possible advantageously to make do with a single bearing surface for the component of the rotary part in question, on which the bearing element of one or more elastically deformable arms is fitted, whereas in the French Patent mentioned above the corresponding component has axially in succession two cylindrical bearing surfaces separated from one another by a transverse shoulder of small extent.
Furthermore, without prejudging the angular orientation to be given to the relevant bearing element in relation to the axis of the assembly, it makes it possible, if desired, to adjust as required, before the axial engagement of this bearing element on the bearing surface provided for this purpose on one of the rotary parts in question, particularly as a function of possible special manufacturing and/or production requirements to be observed, the angular orientation at rest of this rotary part in relation to the other rotary part with which it is associated.
In other words, by means of the arrangment according to the invention, it is possible to adjust, as desired and according to the requirements prevailing at any particular time, in one direction or the other, the circumferential play which exists at rest between the end edges of the receptacles, in which, as regards one of the rotary parts in question, are arranged the springs belonging to the other stages of the elastic means with circumferential action used, and the corresponding edges of the receptacles in which, as regards the other of the said rotary parts, these same springs are likewise arranged.
This results advantageously in a simplification of production, since one and the same arrangement is equally suitable for different productions, and consequently, overall, in a general saving in the assembly as a whole.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial elevation view of a torsion-damping device according to the invention;
FIG. 2 is a view of this in an axial section along the broken line II--II of FIG. 1;
FIG. 3 repeats on a larger scale the details of FIG. 2 identified by an insert III in the latter;
FIG. 4 is, on the scale of FIG. 3, a partial view of the torsion-damping device in a cross-section along the line IV--IV of FIG. 3;
FIGS. 5 and 6 are partial views of this, on the scale of FIG. 3, in an axial section respectively along the lines V--V and VI--VI of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In these Figures, the torsion-damping device in which the invention is used constitutes, by way of example, a clutch plate assembly with a damping hub, especially for a motor vehicle.
In the embodiment illustrated, this clutch plate assembly comprises two coaxial parts, namely a driving part A and a driven part B which are mounted rotably relative to one another within the limits of a specific angular movement and against the action of elastic means designed to act circumferentially between them; subsequently referred to as elastic means with circumferential action.
The driven part B comprises a hub 10 and a hub disc 11 which extends transversely round the hub 10 and which is fixed to the latter.
The hub 10 is designed to be engaged on a shaft, in practice a driven shaft, for example the input shaft of the gearbox, in the particular case, of a clutch plate assembly for a motor vehicle.
To fix it in rotation to such a shaft, the hub 10 in the embodiment illustraed has splines 12 on its inner periphery.
The driving part A comprises two guide washers 13 which extend transversely round the hub 10 on either side of the hub disc 11 and at a distance from the latter and which are fixed to one another by spacers 14 passing with play through notches 15 provided for this purpose on the periphery of the said hub disc 11.
In the embodiment illustrated, there are three of these spacers 14; each having a circular cross-section.
The driving part A also incorporates a friction disc 17 which, via a disc 18, is fixed to the guide washers 13 by means of the axial spacers 14. Friction linings 19 are fixed to the periphery of the disc 18 on either side.
Such a friction disc 17 is intended to be clamped by means of its friction linings 19 between two plates fixed in rotation to a second shaft, in practice a drive shaft, the output shaft of the engine, in this particular case, of a clutch plate assembly for a motor vehicle.
In the embodiment illustrated, the friction disc 17 is coupled by means of its disc 18 to one of the guide washers 13, and located between the periphery of the assembly formed in this way and the hub 10 is a bearing 20 to which is fixed a radial collar 21 inserted axially between the said assembly and the hub disc 11.
Between the rotary parts A, B formed in this way there are friction means with which axially acting elastic clamping means are associated.
In the embodiment illustrated, these friction means consist of a friction washer 22 which is applied to the guide washer 13 opposite that with which the bearing 20 and the radial collar 21 are associated, and which by means of axial lugs 25 engaged for this purpose in recesses 26 in the hub disc 11, the associated axially acting elastic clamping means consisting moreover of an elastic washer 24 of the "ONDUFLEX" type, which, bearing on the hub disc 11, permanently stresses the friction washer 22 in the direction of the guide washer 13 with which it is in contact.
The elastic means with circumferential action, interposed between the rotary parts A, B, comprises springs 28A, 28B of the helical-spring type and an elastically deformable arm 29 cut out from a blank of small thickness 30.
In the embodiment illustrated, two springs 28A are provided in positions diametrically opposite one another, and, alternating with these, two springs 28B are also provided in positions diametrically opposite one another.
These springs 28A, 28B which extend substantially tangentially to a circumference of the assembly are arranged partly in receptacles provided for this purpose in the rotary part B, namely apertures 31 in the hub disc 11, and partly in receptacles provided for this purpose in the rotary part A, namely apertures 32 in the guide washers 13.
In practice, in the configuration at rest of the assembly, as shown in FIG. 1, the springs 28A, 28B are engaged without play in the apertures 32 in the guide washers 13, but the circumferential extent of the apertures 31 in the hub disc 11 is greater than that of the apertures 32, so that in the said configuration of rest there exists, at each of the ends of the springs 28A, 28B, a circumferential play between such an end and the corresponding radial edge of the aperture 31 of the hub disc 11, in which such a spring 28A, 28B is accommodated.
As regards the circumferential direction identified by the arrow F in FIG. 1, which corresponds to the most frequent direction of rotation of the assembly, that is to say that relating to forward movement of the vehicle, and which likewise corresponds to an operation of this assembly in "traction", this play, measured angularly, has a value J1 for the springs 28A and a value J'1, greater than the preceding value, for the springs 28B.
As regards the circumferential direction opposite the preceding one, which corresponds to an operation of the assembly "on the overrun", this play, measured angularly, has for the springs 28A a value J2 less than that of the corresponding play J1, and likewise for the springs 28B it has a value J'2 less than that of the corresponding play J'1.
As regards the elastically deformable arm 29, this extends between two bearing elements 34, 35 with which it is cut out in piece from the corresponding blank 30.
In the embodiment illustrated, the bearing element 34, which is radially the innermost and which, by means described in detail below, is designed to be fixed in rotation in a positive way to one of the rotary parts A, B, in practice the rotary part B, consists of a circularly continuous washer.
In conjunction with this, the bearing element 35, which is radially the outermost and which is provided with drive means designed to connect it in rotation to the other of the rotary parts A, B, in practice the rotary part A, over at least one range of the angular movement between the said rotary parts A, B consists of a circular segment which extends substantially over 180° and which has, projecting radially outwards at each of its end, a pair of radial fingers 37 for engagement for example without play, as illustrated, on the springs 28A.
These radial fingers 37 constitute the drive means for this, as will be described below.
In practice, in the embodiment illustrated, the elastically deformable arm 29 extends over a little less than 360° from a first end, by means of which it is substantially continuous with the circular segment constituting the bearing element 35, to a second end by means of which it engages radially with the washer constituting the bearing element 34.
These arrangements are well known per se, particularly from the French Patent mentioned above, and they will therefore not be described in detail here.
Bearing element 34 is fixed in rotation to the rotary parts B and incorporates, projecting radially from it, at least two barbs 40 which are forceably engaged axially in a bearing surface 41, of different transverse dimensions, of the said rotary part B and between which the said bearing element 34 is elastically deformable radially and circumferentially.
The angle at the centre between two barbs 40 is always relatively large and is preferably always at least 30°. In the embodiment illustrated, only three barbs 40 are thus provided, and, since these barbs are uniformly distributed circularly, the angle at the centre between any two successive barbs is equal to 120°.
In the embodiment illustrated, each of the barbs 40 has a triangular contour, and the angle at the vertes of such a barb 40 is greater than 90° and is, for example, as illustrated, in the neighbourhood of 120°.
The barbs 40 extend on the inner periphery of the washer constituting the bearing element 34 to interact with a bearing surface 41 of the hub 10 of the rotary part B.
As will be noted, this bearing surface 41 is the only one.
In practice, it extends axially on the outside of the guide washer 13 with which a bearing 20 and a radial collar 21 are associated, and the blank 30 from which the elastically deformable arm 29 and its bearing elements 34, 35, are cut out is itself transversely arranged on the outside of the volume delimited by the two guide washers 13.
Between the barbs 40 there is a radial play j between the washer constituting the bearing element 34 and the bearing surface 41 of the hub 10 of the rotary part B.
Between two barbs 40, this washer can thus effectively elastically exercise play radially in relation to this hub 10, as indicated by arrows F' in FIG. 1, as well as circumferentially.
The conventional part of the bearing surface 41 of the hub 10 has transversely a diameter D1 greater than that D2 of the circumference C on which is located the end point of the barbs 40, as indicated by broken lines in FIG. 4.
Furthermore, the material constituting the blank 30, and threfore these barbs 40, has a hardness higher than that of the material constituting the hub 10.
For example, the blank 30 can be made of hardened and/or cyanide-hardened steel, and the hub 10 can be made only of medium-hard steel.
The blank 30 is forceably engaged on the hub 10, more specifically on the bearing surface 41 of the latter, for example after the assembly has been fitted together.
During this engagement, the barbs 40 which it incorporates machine on the bearing suface 41 of the hub 10 furrows or grooves 44 of complementary transverse contour.
The engagement of the blank 30 on the hub 10 is continued until this blank 30 is engaged firmly with the springs 28A, as mentioned above, by means of the radial fingers 37 of the circular segment constituting the bearing element 35.
The configuration of rest of the assembly is determined thereby, the guide washers 13 of the rotary part A being wedged on the springs 28A and these being in turn wedged on the rotary part B by means of the blank 30.
In other words, in this configuration of rest, the circumferential plays J1, J2, J'1, J'2 mentioned specifically above are determined.
However, as will be understood, before the blank 30 is put in place, it is possible, as required, to give the rotary part B any angular orientation in relation to the rotary part A about the axis of the assembly and within the limits of the total circumferential play J1+J2 associated with the springs 28A.
As a result, it is possible, without modifying the elements used, to adjust, as desired, the relative value of the plays J1, J2 and consequently J'1, J'2 for the configuration of rest of the assembly.
It is sufficient, for this purpose, before the blank 30 is fitted, to give a suitable angular orientation to the rotary part B in relation to the rotary part A, and the blank 30, after it has been fitted, automatically fixes in a definitive way, as mentioned specifically above, the configuration of rest selected in this way for the assembly.
Moreover, during the fitting of the blank 30 on the bearing surface 41 of the hub 10, each of the barbs 40 axially displaces material from the hub 10, and the latter forms locally a bead 46 at the end of the corresponding furrow 44.
Thus, on the axially inner side of the washer forming the bearing element 34, each of the barbs 40 is axially up against such a local bead 46 on the corresponding bearing surface 41 of the rotary part B in question.
Because of the elastic clamping force to which the barbs 40 are subjected and also because the blank 30 does not undergo any axial force, no special measure need normally be taken to retain this blank axially on the hub 10.
However, if desired and as illustrated, there can be for safety's sake, on the axially outer side of the washer forming the bearing element 34, crimping beads 47 which, originating as a result of the upsetting of material of the bearing surface 41 of the hub 10, are in contact with the said washer, preferably without disturbing its capacity for elastic radial deformation.
In fact, and without any increase in costs, such crimping beads 47 can be formed even during the positioning of the blank 30.
Consequently, these crimping beads 47 are each individually arranged circularly between two barbs 40 at the end of an individual axial furrow 48 resulting from their formation.
For the assembly to operate in "traction", (the direction of rotation of the said assembly being that identified by the arrow F in FIG. 1) a torque is applied in an increasing trend to the rotary part A, and this torque is initially transmitted via the single elastically deformable arm 29 to the rotary part B, as described in detail in the French Patent mentioned above.
This first operating phase continues until the circumferential play J1 is absorbed.
The springs 28A are activated in turn, adding their effects to that of the elastically deformable arm 29 which remains tensioned.
Then, when the circumferential play J'1 is absorbed in turn, the springs 28B are also activated, adding their effects to those of the springs 28A and of the elastically deformable arm 29, until, because the turns of at least any one of these springs become contiguous to one another or because the spacers 14 come up against the corresponding radial edge of the notches 15 in the hub disc 11, through which they pass, there is direct positive drive of the rotary part B by the rotary part A, the transmitted torque then being sufficient.
For a decreasing trend in the torque between these rotary parts, corresponding to an operation of the assembly "on the overrun", a process opposite that described briefly above takes place, until, if appropriate, the said assembly returns to its initial configuration of rest.
Provided that there remains a capacity for elastic radial and circumferential deformation of the relevant bearing element between two barbs, there can be any number of barbs which the latter possesses to fix it in rotation to the rotary parts in question.
Furthermore, this rotary part is not necessarily the radially innermost rotary part, but may be the radially outermost rotary part, in which case the barbs possessed by the corresponding bearing element project, for example, on the outer periphery of the latter.
Finally, the scope of application of the invention is also not limited to that of torsion-damping devices comprising only two coaxial parts mounted rotatably relative to one another, but also extends to that of torsion-damping devices comprising a greater number of such parts.
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A torsion-damping device of the kind comprising two rotary parts capable of limited relative angular displacement with elastic means interposed circumferentially between the two rotary parts, incorporates an elastically deformable arm extending between two bearing elements one of which is fixed in rotation to one of the rotary parts. This bearing element incorporates at least two radially projecting barbs which are forceable engaged axially in a bearing surface of the respective rotary part and between which it is elastically deformable radially and circumferentially. The invention is especially applicable to damping hubs for clutch plate assemblies in motor vehicles.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to copending U.S. provisional application entitled, “Fibreboard Sheets With Vacuum Breaking Perforations,” having Ser. No. 60/234,729, filed Sep. 22, 2000, which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention relates to palletizing sheets for receiving, handling, storing and shipping a unitized load product and, more particularly, to an improved palletizing sheet for use in automated palletizing systems.
BACKGROUND OF THE INVENTION
[0003] In many applications, product, e.g., cartoned or bagged product, is unitized to achieve economies by receiving, shipping, handling and storing the product in bulk loads. For many years, these unitized loads were carried on conventional hard wood pallets. The wooden pallet system for handling unitized loads was adopted and became the most popular system initially because the wood pallet was low in cost, availability of wood was adequate, and it was easy to handle the product on the wooden pallet with a standard forklift truck. However, the use of wooden pallets has suffered from a number of disadvantages. These include high initial investment cost, problems in inventorying and storage, high cost of pallet maintenance to keep the pallets in service, high cost of pallet replacement, problems of lost pallets, and high weight and volume which add significant cost to shipment and space requirements for storage of the pallets. Because wooden pallets are rather bulky and require large amounts of space for storage, they are often stored in the outside environment between uses. As such, they are susceptible to the elements and infestation by both rodents and insects, which can ultimately lead to infestation of the products to be palletized. As well, wooden pallets can also cause damage to the load during handling and storage, for example, by nails and broken boards rupturing packages mounted on the pallets.
[0004] For these and other various reasons, the palletizing sheet method of handling unitized loads was adopted and its use has continued to expand up to the present day. A palletizing sheet is a thin sheet of material that is of a length and width generally the size of the unit load. Various constructions of palletizing sheets perform different functions within the palletizing process. For example, there are those palletizing sheets upon which an entire unitized load is placed, and there are those sheets that are placed between the various layers of a given load. The former are often referred to as slipsheets, and the latter as tiersheets. Slipsheets typically have one or more “pull tabs” which extend about three or four inches beyond the load, allowing the slipsheet to be gripped and pulled onto the platens of a forklift truck with the aid of a gripper or push-pull attachment mounted to the forklift truck. Typically, the slipsheets are provided with pull tabs on adjacent sides allowing the load to be picked up either from the front or the side for convenience of loading and full utilization of trailer width. However, they can be made with any number of tabs. Tiersheets, on the other hand, typically do not require pull tabs because they are placed between the various layers of a load.
[0005] In the palletizing or unitizing process, a stack of palletizing sheets is typically provided for use in assembling multiple loads. The sheets are sequentially picked up and transferred one by one to a loading area, and the load unitized on the palletizing sheet for shipment. Typically, the top palletizing sheet of the stack is removed from the stack and transferred to the loading area by means of a suction gripping apparatus. This is a device that includes one or more gripping heads to which suction is applied. The suction causes the gripping heads to grip the upper surface of the top palletizing sheet. The gripper with attached palletizing sheet is then transferred to the loading and/or palletizing area where the suction is released, in turn releasing the palletizing sheet. The gripper is then moved back to the stack of palletizing sheets to grip the sheet now at the top of the stack, and the process is repeated. The load to be palletized is placed on the palletizing sheet, which has been transferred, and that load is secured such as by stretch wrapping. As noted above, the palletizing sheet underlying the entire load is the slipsheet, and tiersheets may or may not be used within the load to separate various layers. The palletized load, along with its underlying slipsheet, is then transferred to a storage or transport area. Once this load is removed, the next palletizing sheet is gripped by the transfer apparatus and transferred to the loading and/or palletizing area. This transfer process from the stack of palletizing sheets to the loading area continues until the stack is exhausted.
[0006] A major problem that has been observed with this method of transferring palletizing sheets is that, often, a vacuum exists between the top palletizing sheet and subsequent sheets. Consequently, the vacuum may cause one or more sheets, in addition to the top palletizing sheet, to be transferred to the palletizing area at the same time. Generally, this problem occurs in palletizing sheets having a thickness on the order of between 0.02 inch to 0.120 inch. As a result, there exists a significant problem in handling and transporting palletizing sheets using the suction gripping method of transfer.
[0007] Prior art attempts to solve this problem have included embossing or lightly dusting the surfaces of the palletizing sheets in an effort to allow airflow between adjacent sheets. Although such methods have reduced the problem of multiple palletizing sheet pick-ups, they have not eliminated the problem.
SUMMARY OF THE INVENTION
[0008] The problem of multiple palletizing sheet transfer described above is overcome without the use of embossing rollers or the added processing step of applying fine dust to the boards. In accordance with the present invention, the palletizing sheets are provided with at least one perforation that extends from the upper surface to the lower surface of each palletizing sheet. The perforations are such that when the palletizing sheets are stacked upon one another, the perforations form an airflow passage between the upper surface of the top palletizing sheet and the bottom surface of the top sheet, which is in contact with the upper surface of the adjacent palletizing sheet. By so providing, any potential vacuum existing between adjacent palletizing sheets during suction transfer will be negated and the transfer of individual palletizing sheets, one at a time, will be possible. The perforations are normally placed on the palletizing sheet such that it will not be within the area on the palletizing sheet contacted by the suction gripper apparatus.
[0009] Palletizing sheet formation is well known in the prior art. Numerous means may be adequate for forming the perforations required in the present invention. However, a preferred embodiment of the present invention would include palletizing sheets which are cut to the desired size. After the palletizing sheet is the desired size, the desired number of perforations would be die cut at the necessary locations and in the necessary shapes and sizes.
[0010] These and other objects and advantages of the details of construction will become apparent upon reading the following description of the illustrative embodiment describing the principles of the present invention with reference to the attached drawings wherein like reference numerals have been used to refer to like parts throughout the several figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIGS. 1 A- 1 F are top views of palletizing sheets of the present invention showing various embodiments of perforation shape, number and location.
[0012] [0012]FIG. 2 is a flow chart depicting the process of using palletizing sheets of the present invention in the palletizing/unitizing process.
[0013] [0013]FIG. 3 is a top view of the palletizing sheet as shown in FIG. 1A, showing various placements of a suction gripper apparatus.
[0014] [0014]FIG. 4 is a partial side view of the palletizing sheet as shown in FIG. 1F, along line IV-IV.
[0015] [0015]FIG. 5 is a flow chart depicting a process of producing palletizing sheets of the present invention.
DETAILED DESCRIPTION
[0016] Referring now to FIGS. 1 A- 1 F, in the automated palletizing process, a load which is unitized, for example, by taping, tying, gluing, cartoning or stretch wrapping, has a defined unit width and length. A palletizing sheet 10 is the medium upon which the unit load is placed, and is sized in accordance with the size of the load to be placed thereon. Palletizing sheets 10 are often placed between the various layers of the unit load. The underlying palletizing sheet 10 (commonly referred to as a slipsheet) typically has two pull tabs 12 , generally three to four inches in width, on adjacent sides of the palletizing sheet upper surface 14 (defined by edges 16 ) which facilitate transferring the unitized load once it has been placed on the palletizing sheet 10 . However, any shape or number of tabs 12 may be used, and may be configured about the edges 16 of the palletizing sheet 10 as desired. An indentation is often provided consistent with the edge 16 along which a pull tab 12 is attached. Although not necessary, the indentation permits the pull tab 12 to be more readily deflected, thereby allowing a gripper apparatus on a forklift (not shown) to more easily grasp the pull tab. Also, in that the pull tab 12 is more easily deflected, it is less likely to puncture and damage adjacent goods than is a pull tab without the capability to deflect. Those palletizing sheets 10 that are placed between various layers of the unit load (commonly referred to as tiersheets) typically have no pull tabs 12 .
[0017] Note that any number of perforations 18 can be used, and that the location of those perforations can also be varied as desired. Any shape (circular, triangular, square, irregular, etc.) can be used for the perforation 18 so long as adequate airflow is allowed therethrough, thereby negating any potential vacuum that may exist between adjacent palletizing sheets 10 during transfer of the top palletizing sheet 10 . Although various shapes, sizes, numbers and locations, of perforations 18 are within the scope of the present invention, in the preferred embodiment represented in FIG. 1A, the palletizing sheet upper surface 14 has three perforations 18 , one being distributed in each of three comers. In the preferred embodiment, predominantly circular perforations 18 , approximately 0.250 inches in diameter, have been found to perform satisfactorily. Note, however, that the required size of the perforations 18 can vary greatly depending on the number of perforations used, as well as the thickness of the palletizing sheet 10 and the material used in its construction. For example, perforations 18 with diameters ranging from 0.1 inch to 3.0 inches have been found to function adequately without jeopardizing the structural integrity of the palletizing sheets 10 . Although the perforations 18 may be formed at any location on the upper surface 14 of the palletizing sheet, placement in the comers approximately three inches from adjacent edges 16 of the upper surface has been found to perform satisfactorily.
[0018] The palletizing or unitizing process is depicted in FIG. 2. First, as shown in block 200 , a stack of palletizing sheets 10 is provided. Typically, the palletizing sheets 10 of the stack are picked up and transferred to a loading station, one at a time. The top palletizing sheet 10 of the stack is picked up and transferred to the loading area by a suction gripping apparatus, (not shown) as is well known in the art. The suction gripping apparatus typically has one or more gripping heads. As described in block 202 , the suction heads are normally positioned on the upper surface 14 of the top palletizing sheet 10 , such that the gripper heads do not encompass any of the perforations 18 . FIG. 3 shows the palletizing sheet 10 of FIG. 1A with potential placements of the gripper head (not shown) depicted as broken circles. Next, the gripper head is used to create a suction, thereby “gripping” the top palletizing sheet 10 , as described in block 204 . This is the point at which prior art systems experience problems. Because of the tendency for a natural vacuum to form between the top palletizing sheet 10 and those subsequent palletizing sheets 10 in the stack, the simultaneous transfer of multiple palletizing sheets 10 often occurs with prior art systems.
[0019] As previously noted, perforations 18 are used to overcome this problem by “breaking” the natural vacuum that may develop between adjacent palletizing sheets 10 , as described in block 206 . As shown in FIG. 4, as the top palletizing sheet 10 is lifted from the stack, air passes through the perforations 18 (as depicted by the arrows) and between the bottom surface 15 of the top palletizing sheet 10 and the upper surface 14 A of the adjacent palletizing sheet 10 A, thereby preventing the formation of a natural vacuum. As such, only the top palletizing sheet 10 will be lifted and transferred to the loading and/or palletizing area, as described in block 208 . Once in the loading and/or palletizing area, the suction is released, in turn releasing the palletizing sheet 10 . As described in block 210 , once a load is placed on the palletizing sheet 10 , the load and associated palletizing sheet 10 are removed to a storage or transport area. Again, palletizing sheets 10 may also be used between various layers of the load when desired.
[0020] Although numerous materials can be used to produce the palletizing sheets 10 of the present invention (i.e., plastic, nylon, polymers, fibreboard, chipboard), the preferred embodiment includes laminating multiple plies of paperboard material, such as kraft paper. One method of manufacturing palletizing sheets 10 in accordance with the present invention is described in FIG. 5. First, as described in block 500 , multiple plies are laminated together, as in a paster. Next, as described in block 502 , the palletizing sheets 10 are cut to the desired size. Frequently, this is dictated by factors such as load size, load weight, or space available in a transport vehicle or storage facility. Finally, as described in block 504 , the desired number and shape of perforations 18 are created in the palletizing sheets 10 at the desired locations. In the preferred embodiment, the perforations are die-cut; however, other methods or means of providing the perforation or perforations can be employed to produce the same result and are considered to be within the scope of the present invention. In its simplest form, the perforation or perforations could be cut by hand. Single ply or multi-ply palletizing sheets 10 are encompassed within the scope of the present invention. Whether single ply or multi-ply sheets are required will depend on factors such as the material, dimensions and weight of load, etc.
[0021] It should be emphasized that the above-described embodiments of the present invention, particularly, any “preferred” embodiments, are merely possible examples of implementations, merely set forth for a clear understanding of the principles of the invention. Many variations and modifications may be made to the above-described embodiment(s) of the invention without departing substantially from the spirit and principles of the invention. All such modifications and variations are intended to be included herein within the scope of this disclosure and the present invention and protected by the following claims.
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A perforated palletizing sheet 10 and method for forming such palletizing sheets 10 for receiving, handling, storing and shipping unitized loads. The method includes placing at least one perforation 18 in a upper surface 14 of the palletizing sheet 10 . The size, shape, number, and placement of perforations 18 acting to prevent formation of a vacuum between adjacent sheets such that when an attempt is made to transfer the top palletizing sheet 10 from a stack thereof, only the top sheet is transferred.
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This is a divisional of U.S. patent application Ser. No. 09/876,509 filed on Jun. 7, 2001 now U.S. Pat. No. 6,735,155, which is a divisional of U.S. patent application Ser. No. 08/834,715 filed on Apr. 1, 1997 now U.S. Pat. No. 6,252,838.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is related with an information recording method and apparatus for adding and recording new record information subsequent to old record information recorded previously on a recordable information record medium, such as a high-density optical disc and the like, represented by DVD-R (DVD-Recordable) on which the information can be recorded only once.
2. Description of the Related Art
Generally, in the recordable information record medium on which the information can be recorded only once, when it is tried to later overwrite the new record information to an area on which the old record information has once been recorded, both the old record information and the new record information may be broken.
In the information recording method and apparatus for adding and recording the new record information to this kind of the recordable information record medium, when recording the new record information subsequent to the old record information, a linking area (or a boundary area) corresponding to an information amount of a single error correction unit, such as an ECC (Error Correcting Code) block and the like according to the error correcting system used therein, was conventionally provided at the linking or boundary portion of the old record information and the new record information. In the linking area, a meaningless dummy information or a predetermined RF (Radio Frequency) signal is recorded at a last portion of the old record information or a first portion of the new record information, and then the new record information is recorded thereon.
The reason why this linking portion is provided is as follows. If the linking portion is not provided, at the time of consecutively reproducing the new record information, recorded later, as well as the old record information, the RF signal may be discontinuous at the boundary of the record area of the old record information and the record area of the new record information, thereby resulting in an unstable focus servo or tracking servo control.
The reasons why the linking portion is provided for the data capacity corresponding to one ECC block is and why the meaningless dummy information or the like is recorded therein are explained below. In the conventional error correcting process, the error correction is performed by each error correction unit. If the new record information is recorded from the middle of the error correction unit, the appropriate error correction can not be performed for a head portion of the new record information, at the time of consecutively reproducing the old record information and the new record information later. Thus, the appropriately continuous reproduction can not be performed. In this regard, if the meaningless dummy information or the predetermined RF signal is recorded for one ECC block within the linking area as mentioned above, it is possible to reproduce the old record information and the new record information continuously by skipping the linking area and reproduce the new record information from an ECC block next to the linking portion, even though the overlapped portion of the old record information and the new record information in the linking portion is broken.
Further, another reason why the linking area is provided is as follows. If the new record information is recorded to follow the old record information without providing the linking area, both of the old record information and the new record information may be broken at the overlapped portion of them. In that case, if the information broken portion exceeds a single error correction unit, it is impossible to recover the broken record information. For the reasons described above, the linking area is provided at the linking or boundary portion of the old record data and the new record data.
However, the conventional error correction unit has relatively large capacity, for example, approximately 32K bytes, and this area is entirely filled with meaningless information having no relation with the recorded information. Therefore, there is a problem that it results in an extremely ineffective use of the high-density disk or the like, which needs to record a large amount of information.
SUMMARY OF THE INVENTION
The present invention is proposed from the viewpoint of the above mentioned problems. It is therefore an object of the present invention to provide an information recording method and apparatus, which can add and record new record information with effectively utilizing a record area on an information record medium and accurately perform a consecutive and successive reproduction of old record information and new record information.
According to one aspect of the present invention, there is provided an information recording method including the steps of: applying a predetermined processing to record information divided into error correction units and generating processed record information including a plurality of record units; recording the processed record information on an information record medium; and recording, after the recording of the processed record information, predetermined dummy information for an information amount corresponding to the plurality of record units, on the information record medium, subsequent to the processed record information recorded.
In accordance with the method thus designed, a predetermined processing is applied to record information to generate processed record information. Then, the processed record information is recorded on the information record medium, and dummy information is recorded for the information amount of plural record units, subsequent to the processed record information thus recorded. Therefore, in a case of consecutively reproducing the processed record information, by replacing the reproduced dummy information with pre-set data, it is possible to perform the consecutive reproduction while carrying out the error correction within a range of an error correction capability.
The method may further include the step of overwriting dummy information including the steps of: detecting a head position of an old dummy information previously recorded on the information record medium; and recording new dummy information on the information record medium, based on the detected head position, such that a total information amount of the old dummy information after the recording of the new dummy information and the new dummy information recorded is no more than an information amount of one error correction unit.
In accordance with the method thus designed, a head position of an old dummy information previously recorded on the information record medium is detected. Then, new dummy information is recorded on the information record medium, based on the detected head position, such that a total information amount of the old dummy information after the recording of the new dummy information and the new dummy information recorded is no more than an information amount of one error correction unit.
Further, the processed record information recording step may further include the step of recording new record information on the information recording medium from a position subsequent to the new dummy information recorded. Still further, the dummy information recording step may record the new dummy information over a part of the old dummy information previously recorded.
Thus, the new record information is added and recorded subsequent to dummy information whose content is known in advance. As a result, in a case of consecutively reproducing old record information recorded prior to the old dummy information and the new record information, it is possible to perform the consecutive reproduction while carrying out the error correction within the range of the error correction capability. Since the total information amount of the old dummy information and the new dummy information is no more than that of one error correction unit, within the linking portion of the old record information and the new record information, it is possible to make an area used for recording the record information larger, as compared with the case of providing a linking portion corresponding to one error correction unit. In addition, since the recording area of the old and new dummy information, which may likely be broken due to the overwriting, is smaller than a single error correction unit, the error correction of the neighboring record information is not disturbed. As a result, it is possible to accurately perform the consecutive reproduction.
Alternatively, the processed record information recording step may include the steps of: detecting a head position of the dummy information previously recorded on the information record medium; determining a recording start position from which new record information is recorded on the basis of the detected head position of the dummy information and an information amount in a single error correction block which is a minimum information unit of error correction; calculating an information removal amount corresponding to an information capacity in an area from the head position to the recording start position; removing the record information corresponding to the calculated removal amount from a head of the record information so as to produce an actual record information; and recording the actual record information from the recording start position onto the information recording medium.
In accordance with the method thus designed, an information amount of the new record information at the head portion, which may likely be broken at the time of recording the new record information, is no more than the correction block that is the minimum unit for an error correcting process. Accordingly, it is possible to minimize the deterioration of the error correction performance in consecutively reproducing the old record information and the new record information. As a result, even if there is dust or the like on the information record medium at the time of reproduction, it is possible to achieve reliable error correction performance. Moreover, there is apparently no existence of the linking portion between the old record information and the new record information because the dummy information portion recorded previously and the new record information, which is likely be broken, are restorable by the error correction. As a result, it is possible to make the area used for recording the record information larger, as compared with the case of providing the linking portion corresponding to the entire error correction unit.
Also, the recording start position determining step may determine the recording start position within an area where the dummy information is previously recorded. By this, new record information is recorded subsequent to the dummy information having a content that is known in advance. As a result, it is possible to make the deterioration of the error correction performance smaller, when consecutively reproducing the old record information and the new record information.
According to another aspect of the present invention, there is provided an information recording apparatus including: a unit for applying a predetermined processing to record information divided into error correction units and generating processed record information including a plurality of record units; a unit for recording the processed record information on an information record medium; and a unit for recording, after the recording of the processed record information, predetermined dummy information of an information amount corresponding for the plurality of record units, on the information record medium, subsequent to the processed record information recorded.
The apparatus may further include a unit means for overwriting dummy information including: a unit for detecting a head position of an old dummy information previously recorded on the information record medium; and a unit for recording new dummy information on the information record medium, based on the detected head position, such that a total information amount of the old dummy information after the recording of the new dummy information and the new dummy information recorded is no more than an information amount of one error correction unit.
Still further, the processed record information recording unit may further include a unit for recording new record information on the information recording medium from a position subsequent to the new dummy information recorded. Also, the dummy information recording unit may record the new dummy information over a part of the old dummy information previously recorded.
Alternatively, the apparatus may be so configured that the processed record information recording unit includes: a unit for detecting a head position of the dummy information previously recorded on the information record medium; a unit for determining a recording start position from which the new record information is recorded on the basis of the detected head position of the dummy information; a unit for calculating an information removal amount corresponding to an information capacity in an area from the head position to the recording start position; a unit for removing the record information corresponding to the calculated removal amount from a head of the record information to produce an actual record information; and a unit for recording the actual record information from the recording start position onto the information recording medium. Further, the recording start position determining unit may determine the recording start position within an area where the dummy information is previously recorded.
The nature, utility, and further features of this invention will be more clearly apparent from the following detailed description with respect to preferred embodiments of the invention when read in conjunction with the accompanying drawings briefly described below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a view showing a data structure of record information in an embodiment,
FIG. 1B is a view showing a configuration of an ECC block in the record information of the embodiment,
FIG. 2 is a view showing a physical format of the record information of the embodiment,
FIG. 3 is a block diagram showing a schematic configuration of an information recording apparatus according to the present invention,
FIG. 4 is a flow chart showing a process according to a first embodiment of an information recording operation;
FIG. 5 is a view explaining the recording manner of the record information by the process of the first embodiment;
FIG. 6 is a flow chart showing a process according to a second embodiment of the information recording operation; and
FIG. 7 is a view explaining the recording manner of the record information by the process of the second embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Next, preferred embodiments of the present invention are explained with reference to the drawings. The following embodiments explain the embodiments in which the present invention is applied to an information recording apparatus for recording information on a DVD-R.
(I) Embodiment of Record Format
At first, a generally physical format for recording record information on the DVD-R and an error correcting process in the record information are explained with reference to FIGS. 1 and 2 .
The error correcting process in the DVD-R of this embodiment and an ECC block, serving as an error correction unit, in the error correcting process are firstly explained with reference to FIGS. 1A and 1B .
Generally, the record information recorded on the DVD-R has a physical structure including a plurality of data sectors 20 shown in FIG. 1A . One data sector 20 is composed of, from a head portion thereof, an ID information 21 indicative of a start position of the data sector 20 , an ID information error correction code (IEC) 22 for correcting errors of the ID information 21 , a reserve data 23 , a data 24 which is the main data to be recorded, and an error detection code (EDC) 25 for detecting errors in the data 24 . The record information to be recorded is constituted by a continuous plurality of the data sectors 20 .
Next, process for constituting the ECC block by the data sectors 20 are explained with reference to FIG. 1B .
When constituting an ECC block 30 by the data sectors 20 , one data sector 20 is firstly divided into plural blocks each of which is 172 bytes data, as shown in FIG. 1B , and each divided data (this is hereafter referred to as a “data block 33 ”) is arranged in a vertical direction (refer to the left side of FIG. 1B ). At this time, the data blocks 33 are arranged in 12 lines in the vertical direction.
For each data block 33 arranged in the vertical direction, ECC internal code (PI (Parity In) sign) 31 having 10 bytes data is affixed to the end of the data block 33 to constitute one correction block 34 (refer to right side of FIG. 1B ). At this stage, the correction blocks 34 to which the ECC internal codes 31 are affixed are arranged in 12 lines in the vertical direction. After that, this process is repeated with respect to 16 data sectors 20 . Accordingly, the correction blocks 34 of 192 lines are obtained.
Then, the correction blocks 34 of 192 lines are divided in the vertical direction from the beginning thereof, for each one byte, in the state that the 192 lines of the correction blocks 34 are arranged in the vertical direction. 16 ECC external codes (PO (Parity Out) signs) 32 are affixed to each of the vertically divided data blocks. It is noted that the ECC external code 32 is also affixed to a portion of the ECC internal code 31 within the correction block 34 .
From the above mentioned process, one ECC block 30 including 16 data sectors 20 is produced as shown in FIG. 1B (right side). At this time, a total amount of the information included within one ECC block 30 is expressed by an equation described below.
(172+10) bytes×(192+16) lines=37856 bytes
The actual data 24 (i.e., other than ECC codes) in it is expressed by an equation described below.
2048 bytes×16=32768 bytes
In the ECC block 30 shown in FIG. 1B , data of one byte is indicated by [D#. *]. For example, [D 1 . 0 ] indicates the data of one byte positioned at a first line and a zeroth column, and [D 190 . 170 ] indicates the data of one byte positioned at a 190th line and a 170th column. Thus, the ECC internal codes 31 are positioned at 172nd to 181st columns, and the ECC external codes 32 are positioned at 192nd to 207th lines. The correction blocks 34 are consecutively recorded on the DVD-R.
The reason why the ECC block 30 is constituted so as to include both the ECC internal code 31 and the ECC external code 32 , as shown in the right side of FIG. 1B , is that the data arranged in the horizontal direction in FIG. 1B is corrected by the ECC internal code 31 and the data arranged in the vertical direction is corrected by the ECC external code 32 . That is, it is possible to perform the error correction in both the horizontal and vertical directions within the ECC block 30 shown in FIG. 1B . Thus, the effective and stable error correction can be performed as compared with the error correcting process used in the conventional CD (Compact Disk) and the like.
More concretely, for example, even if a certain one of the correction blocks 34 (as mentioned above, consecutively recorded on the DVD-R and each totally having the data of 182 bytes including the ECC internal codes 31 for one line) is entirely broken by defect and the like existing on the DVD-R, it is merely the one-byte data break with respect to the ECC external codes 32 at one column, as viewed in the vertical direction. Thus, by carrying out the error correction using the ECC external codes 32 at each column, it is possible to appropriately carry out the error correction to restore the original correct information from the broken information, even though one correction block 34 is entirely broken.
The manner of actually recording on the DVD-R the data sectors 20 included in the ECC blocks 30 shown in FIG. 1B is explained with reference to FIG. 2 . In FIG. 2 , the data indicated in [D#. *] corresponds to the data described in the right side of FIG. 1B .
In recording the ECC blocks 30 , on the DVD-R, the ECC blocks 30 are firstly aligned along one line in a horizontal direction for each correction block 34 , as shown in a top stage of FIG. 2 , and then are interleaved to be divided into 16 recording sectors 40 . At this time, one recording sector 40 includes information of 2366 bytes (=37856 bytes/16), and the data sectors 20 and the ECC internal codes 31 and the ECC external codes 32 are included in the manner being mixed with each other in the recording sector 40 . However, the ID information 21 (refer to FIG. 1A ) in the data sector 20 is positioned at a head portion of each recording sector 40 .
The recording sector 40 is divided into a plurality of data 41 each having 91 bytes, and a header H is added to each data 41 . After that, one sync frame 42 is produced from one data 41 by 8-16-modulating the recording sector 40 including the pairs of the header H and the data 41 . At this time, one sync frame 42 is composed of a header H′ and data 43 . Further, an information amount within one sync frame 42 is expressed by an equation described below.
91 bytes×8×(16/8)=1456 bytes
Then, the information is written to the DVD-R 1 in a form of the continuous sync frames 42 . At this time, one recording sector 40 includes 26 sync frames 42 .
By constituting the above explained physical format to record the information on the DVD-R, the 8-16-demodulation and de-interleave (refer to FIG. 2 ) are performed at the time of reproducing the recorded information to thereby reproduce the original ECC block 30 and to perform the effective error correction to accurately reproduce the information.
(II) Embodiment of Information Recording Apparatus
Next, an embodiment of an information recording apparatus, in accordance with the present invention, for recording information on the DVD-R 1 according to the physical format explained with reference to FIGS. 1 and 2 is explained with reference to FIGS. 3 to 7 . Here, the following assumptions are made in the embodiment described below. That is, in the DVD-R 1, pre-pits carrying address information on the DVD-R 1 and the like are formed in advance on the information tracks, on which the record information is to be recorded. Then, in recording the record information, the address information on the DVD-R 1 is obtained by detecting the pre-pits. By this, a record position on the DVD-R 1 where the record information is to be recorded is detected, and then the record information is recorded.
A configuration of the information recording apparatus in accordance with the present invention is firstly explained with reference to FIG. 3 .
As shown in FIG. 3 , an information recording apparatus S of the embodiment is provided with a pick-up 2 , a reproduction amplifier 3 , a decoder 4 , a pre-pit signal decoder 5 , a spindle motor 6 , a servo circuit 7 , a processor 8 , an encoder 9 , a switch 10 , a power control circuit 11 and a laser drive circuit 12 .
Next, a whole operation is explained.
The pick-up 2 includes a laser diode, a deflection beam splitter, an objective lens, light detectors and the like (not shown), and irradiates a light beam B onto the information record surface of the DVD-R 1 on the basis of a laser drive signal S DL , and detects the pre-pits on the basis of a reflected light thereof to thereby record the record information. Moreover, in a case of the existence of old record information that has already been recorded, the pick-up 2 detects the old record information on the basis of the reflected light of the light beam B.
Then, the reproduction amplifier 3 amplifies a detection signal S DT including the pre-pits outputted by the pick-up 2 and the information corresponding to the old record information that has already been recorded, outputs a pre-pit signal S PP corresponding to the pre-pits, and also outputs an amplification signal S P corresponding to the old record information.
After that, the decoder 4 applies the 8-16-demodulation and the interleave to the amplification signal S P to thereby decode the amplification signal S P and then outputs a demodulation signal S DM and a servo demodulation signal S SD .
On the other hand, the pre-pit signal decoder 5 decodes the pre-pit signal S PP to thereby output the demodulation pre-pit signal S PD .
The servo circuit 7 outputs a pick-up servo control signal S SP for focus servo control and tracking servo control in the pick-up 2 , on the basis of the demodulation pre-pit signal S PD and the servo demodulation signal S SD , and also outputs a spindle servo signal S SS for servo-controlling the rotation of the spindle motor 6 for rotating the DVD-R 1.
Along with this, the processor 8 temporally stores and outputs a record information signal S R corresponding to the record information that is inputted from an external portion, and also outputs to the external a reproduction signal S OT corresponding to the old record information on the basis of the demodulation signal S DM , and further outputs a switch signal S SW described later, on the basis of the demodulation pre-pit signal S PD .
The encoder 9 affixes the ECC internal code 31 and the ECC external code 32 to the record information signal S R to thereby constitute the ECC block 30 , and also applies the interleave and the 8-16-modulation to the ECC block 30 to thereby output an encode signal S RE .
At this time, the switch 10 switches between the encode signal S RE and a ground signal to thereby output as an output signal S PC .
Then, the power control circuit 11 outputs a drive signal S D for controlling an output of the laser diode (not shown) within the pick-up 2 on the basis of the output signal S PC .
After that, the laser drive circuit 12 actually drives the laser diode on the basis of the drive signal S D to thereby output a laser drive signal S DL for emitting the light beam B.
Further, the information recording apparatus S may reproduce the information recorded on the DVD-R 1. In that case, the reproduction signal S OT is outputted to the external through the processor 8 on the basis of the demodulation signal S DM .
An operation for finishing the recording of record information and an operation for starting the additional recording of new record information, according to the present invention, are explained with reference to FIGS. 4 to 7 , with classifying the cases.
(III) First Embodiment of Information Recording Operation
The first embodiment of the recording operation of the record information is firstly explained with reference to FIGS. 4 and 5 .
In the information recording operation of the first embodiment, when the recording of old record information (hereinafter referred to as “old data”) is finished, old dummy information (hereinafter referred to as “old dummy data”) 44 having an information amount corresponding to two sync frames 42 is recorded, with an ID information 21 at a head portion, subsequent to the old data. When the additional recording of new record information (hereinafter referred to as “new data”) is started, new dummy information (hereinafter referred to as “new dummy data”) 45 having the same content as the old dummy data 44 is firstly recorded (i.e., overwritten) on an area corresponding to the second sync frame 42 of the areas on which the old dummy data 44 is previously recorded. At this time, a data amount of the new dummy data 45 is determined in such a way that a total data amount of the remainder of the old dummy area after the additional recording of the new dummy data 45 and an area of the new dummy data 45 is equal to or less than the data amount of a single recording sector 40 . After that, the new data which is to be primarily recorded is recorded subsequent to the new dummy data 45 .
FIG. 4 is a flow chart indicating the process of additionally recording information on the DVD-R. FIG. 5 shows the information recording manner of the DVD-R 1 before and after the new data is recorded, according to the first embodiment of the information recording operation.
In FIGS. 4 and 5 , it is assumed that the ID information 21 in the final recording sector 40 of the old data is recorded at the address N, and that the ID information 21 in the recording sector 40 of the old dummy data 44 is recorded at the address (N+1).
In the first embodiment of the information recording operation, as shown in FIG. 4 , when the additional recording of the new data is started, the address N corresponding to the ID information 21 in the recording sector 40 of last old data is searched (Step S 1 ). This operation is performed by the processor 8 , on the basis of the demodulation signal S DM supplied from the decoder 4 .
When the ID information 21 corresponding to the address N is detected, the old data recorded on a recording sector 40 subsequent to the detected ID information 21 is detected (Step S 2 ). Then, it is judged by the processor 8 , on the basis of the demodulation signal S DM from the decoder 4 , whether or not the ID information 21 corresponding to the address (N+1) is detected (Step S 3 ). If the ID information 21 corresponding to the (N+1) is not detected yet (Step S 3 ; NO), the detection of the old data is continued until it is detected. If it is detected, (Step S 3 ; YES), the new dummy data 45 , which contents is [0000 . . . ], for example, having an information amount corresponding to:
(one recording sector—one sync frame)
is supplied from the processor 8 to the encoder 9 to be temporarily stored therein. Then, a record information signal S R corresponding to new record information to be recorded subsequent to the new dummy data 45 is supplied to the encoder 9 , which encodes it and temporarily stores the encoded data therein (Step S 4 ).
At this time, an ECC block 30 for the new data may include the new dummy data 45 , or may not include it, i.e., the ECC block 30 for the new data begins from an end position of the new dummy data 45 and is composed of only new data.
Next, old dummy data 44 (for example, [0000 . . . ]) recorded subsequent to the ID information 21 corresponding to the address (N+1) is detected, and header H at the head portion of each sync frame 42 is detected on the basis of the demodulation signal S DM supplied from the decoder 4 . Then, it is judged by the processor 8 whether or not the area corresponding to a second sync frame 42 is detected in the area of the old dummy data 44 (Step S 5 ). If the area corresponding to the second sync frame 42 is not detected yet (Step S 5 ; NO), the detection of the old dummy data 44 is continued until it is detected. If it is detected (Step S 5 ; YES), the switch 10 is changed over to the terminal A side thereof, on the basis of the switch signal S SW from the processor 8 . By this, the new dummy data 45 temporarily stored in the encoder 9 and new data subsequent thereto are read out as the encode signal S RE , and then are outputted as the output signal S PC via the switch 10 (Step S 6 ). Accordingly, the new dummy data 45 and the new data subsequent thereto are recorded on the DVD-R 1 by means of the light beam B emitted from the pick-up 2 .
The power of the light beam B is maintained to be a constant reproducing power, until the switch 10 is changed over to the terminal A side, as shown in FIG. 5 . After the switch 10 is changed over to the terminal A side (on and after the position corresponding to the head portion of the second sync frame 42 in the area of the old dummy data 44 ), the power of the light beam is repeatedly switched between the recording power and the reproducing power in correspondence with the contents of the new dummy data 45 included in the output signal S PC and the new data subsequent thereto. The reason why the emission of the light beam B is continuously kept at the reproducing power even when the data is not recorded is that the reflected light used for the tracking servo control is required in order to permit the light beam B to trace the information track on the DVD-R 1, even if the data is not recorded there.
At the step 6 , when the switch 10 is changed over to the terminal A side and thereby the new dummy data 45 and the new data are recorded, it is judged by the processor 8 whether or not the new data from the encoder 9 ends (Step S 7 ). If it does not end (Step S 7 ; NO), the recording of the new data is continued while maintaining its original state. If the new data ends (Step S 7 ; YES), the dummy data (for example, [0000 . . . ]) having an information amount corresponding to two sync frames 42 is outputted by the encoder 9 and recorded subsequent to the last new data (Step S 8 ). When the recording of the dummy data is finished, the switch 10 is changed over to the terminal B side (i.e., the ground side), and the power of the light beam B is changed to the reproducing power (Step S 9 ). By this, the additional recording process for the new data is completed.
In the above mentioned process shown in FIG. 4 , the new data is recorded subsequent to the new dummy data 45 as shown in FIG. 5 . Moreover, when the recording of the new data is finished, the dummy data is recorded, for the information amount corresponding to two sync frames 42 , subsequent to the new data thus recorded (the old data in FIG. 5 have been recorded previously by this operation), and then the process is finished. The additional recording of the record information is performed by repeating the above mentioned process. However, in this case, as for the state of the DVD-R 1 at the linking portion between the old data and the new data, the dummy data ([0000 . . . ]) is recorded for the information amount equal to or less than one recording sector 40 , as shown in the lowest stage of FIG. 5 . Here, in a portion where the old dummy data 44 and the new dummy data 45 are overlapped with each other (this is the information amount corresponding to the one sync frame 42 and indicated as the data broken area D (hatched area) in FIG. 5 ), both of the old dummy data 44 and the new dummy data 45 may be broken due to the overwriting of the new dummy data 45 . However, in the case of consecutively reproducing the old data and the new data later, it is known that the dummy data at a boundary between the old data and the new data is [0000 . . . ], even if the data in the D is broken. Therefore, by replacing the data detected from the data broken area D with the known data [0000 . . . ], it is possible to perform the consecutive reproduction without disturbing the error correction in the consecutive reproduction (without deteriorating the error correcting performance in the consecutive reproduction).
In this embodiment, the dummy data is recorded for the data amount corresponding to at most only one recording sector 40 . As a result, it is possible to record more record information by effectively using the recording capacity of the DVD-R 1, as compared with a case of providing a linking area for one ECC block 30 in the conventional manner.
Moreover, the ID information 21 (at the address (N+1)) corresponding to the recording sector 40 positioned at the linking portion between the old data and the new data is never broken because no overwriting is executed on the ID information area 21 (see. address (N+1) in FIG. 5 ). As a result, it is possible to accurately perform the consecutive reproduction of the recorded information.
(IV) Second Embodiment of Information Recording Operation
The second embodiment of the recording operation of record information is explained with reference to FIGS. 6 and 7 .
In the information recording operation of the second embodiment, similarly to the first embodiment, old dummy data 44 of an information amount corresponding to two sync frames 42 is recorded, with an ID information 21 at the head portion, subsequent to the record information.
On the other hand, at the time of the additional recording of new data, the recording is started from the second sync frame of new data, i.e., new data corresponding to first one sync frame 42 is removed from the beginning of the new data.
FIG. 6 is a flow chart indicating the operation of additional recording of the new data after the old data which has already been recorded. FIG. 7 shows the recording manner of the DVD-R 1 before and after the new data is recorded by the second embodiment of the information recording operation.
In FIGS. 6 and 7 , it is assumed that the ID information 21 in the final recording sector 40 of the old data is recorded at the address N, and that the ID information 21 in the recording sector 40 of the old dummy data 44 is recorded at the address (N+1). Moreover, the identical step numbers are given to the operations identical to those of the first embodiment of the information recording operation shown in FIG. 4 , and the explanation of the detailed portions is omitted for those steps.
In the second embodiment of the information recording operation, as shown in FIG. 6 , when the additional recording of the new data is started, the operations identical to the steps S 1 to S 3 shown in FIG. 4 are firstly executed. Then, the ID information 21 at the head portion of the area of the old dummy data 44 is detected.
If the ID information 21 corresponding to the address (N+1) is detected (Step S 3 ; YES), a record information signal S R corresponding to the new record information to be recorded is outputted, without inserting the dummy data, from the processor 8 to the encoder 9 , which encodes the new data and temporarily stores the encoded data therein (Step S 10 ).
After that, the operations identical to those of the steps S 5 to S 9 shown in FIG. 4 are executed. New data from the second sync frame (i.e., after new data of first one sync frame 42 is removed from the beginning of the new data) is recorded from the position corresponding to the second sync frame 42 of the area of the old dummy data 44 . When the all new data is recorded, dummy data of an information amount corresponding to two sync frames 42 is recorded subsequent to the new data. Then, the recording of the new data ends.
The power of the light beam B is maintained to be a constant reproducing power, until the switch 10 is changed over to the terminal A side, as shown in FIG. 5 . After the switch 10 is changed over to the terminal A side (on and after the position corresponding to the head portion of the second sync frame 42 in the area of the old dummy data 44 ), the power of the light beam is switched between the recording power and the reproducing power in correspondence with the contents of the new dummy data 45 included in the output signal S PC and the new data subsequent thereto.
According to the above mentioned process shown in FIG. 6 , at the time of the additional recording of the new data, the recording is performed from the new data of second sync frame, i.e., the new data from which first one sync frame 42 thereof is removed from its beginning, as shown in FIG. 7 . Moreover, when the recording of the new data is finished, the dummy data is recorded for the information amount corresponding to two sync frames 42 , subsequent to the new data thus recorded (like the manner of old data shown in FIG. 7 ). In this way, the process is finished. The additional recording of the record information is performed by repeating the above mentioned process.
In this case, as for the state of the DVD-R 1 at a linking portion between the old data and the new data in the additional recording, data different from the new data is recorded in a portion of first two sync frames 42 from the beginning of the new data, as shown in the lowest stage of FIG. 7 . That is, the old dummy data 44 is recorded at the first one sync frame 42 , and the second sync frame 42 subsequent to it becomes the data broken area D (hatched area). However, in the case of the consecutive reproduction of the old data and new data, since both the ECC blocks of the old data and the new data have the structures of the ECC blocks 30 shown in FIG. 1 , the data amount of the two sync frames 42 corresponds to the one correction block 34 in the ECC block 30 . Thus, as mentioned in the explanation of the ECC block 30 , according to the structure of the ECC block 30 in which the error correction is performed in both the vertical and horizontal directions using the ECC internal code 31 and the ECC external code 32 , even if one correction block 34 is entirely broken, it is only the data break of one byte for the ECC external code 32 at one column as viewed in the vertical direction. Therefore, by carrying out the error correction using the ECC external code 32 at each column, it is possible to appropriately carry out the error correction for the two sync frames 40 (i.e., one correction block 34 ) to thereby perform the accurate reproduction. As a result, the consecutive reproduction can be performed without having substantial influence on the error correction.
Further, the total data amount of the dummy data area and the data broken area D is at most equal to two sync frames 42 , this may not put any substantial influence on the error correction in the consecutive reproduction. Therefore, the consecutive reproduction can be performed without providing relatively large linking area between the old data and the new data (the dummy area becomes a meaningless area in the consecutive reproduction of the old data and the new data). As a result, it is possible to record more information by effectively utilizing the record area on the DVD-R 1, as compared with the case of providing the linking area corresponding to one ECC block 30 in the conventional manner.
Further, the second embodiment provides more improved use of data capacity of the DVD-R 1, compared with the first embodiment. In the first embodiment, the dummy data is recorded in first one recording sector 40 beginning from the address (N+1), and hence one recording area 40 is used entirely in vain (see. FIG. 5 , lowest stage). In contrast, according to the second embodiment, the recording sector 40 beginning from the address (N+1) is recorded with new data, and even though the data brake takes place there, the broken data can be corrected by the ECC function as described above. Therefore, no recording sector is vainly filled with dummy data in the second embodiment, and the data recording efficiency is further improved.
Furthermore, the ID information 21 (corresponding to the address (N+1)) in the recording sector 40 at the linking portion of the old data and the new data is never broken because, in either of the first and the second embodiments, no data is overwritten on the ID information 21 at the address (N+1). As a result, the consecutive reproduction is not suffered by the lack or break of the ID information 21 , thereby enabling the stable consecutive reproduction.
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An information recording apparatus includes: a unit for applying a predetermined processing to record information divided into error correction units and generating processed record information including a plurality of record units; and a unit for recording the processed record information on an information record medium; a unit for recording, after the recording of the processed record information, predetermined dummy information of an information amount corresponding for the plurality of record units, on the information record medium, subsequent to the processed record information recorded.
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BACKGROUND OF THE INVENTION
Materials suitable for such applications as electrical insulation, heat insulation, sound insulation, and decorative building elements consisting essentially of ceramic fibers bonded into an article of a desired geometry utilizing an organic or inorganic binder have been marketed commercially for many years. Depending upon the destined application, which can range from acoustic ceiling tile to wrappings for liquid-carrying pipes, the ceramic fibers employed have included such widely-varying materials as asbestos, calcium sulfate, fiber glass, mica, perlite, cellulose, and mineral wool, to name but a few of the most common.
It is quite apparent that the strength imparted to the final article by the binder is of great significance. The chemical durability and weathering resistance of the binder are also highly important and, where highly elevated temperatures are to be experienced, the binder must demonstrate sufficient refractoriness and heat stability. The use of an inorganic binder generally removes the threat of flammability inherent in the use of organic bonding media.
U.S. Pat. No. 4,239,519 discloses the production of inorganic, crystal-containing gels which perform as precursors for the preparation of papers, fibers, films, boards, and coatings. The patented method for developing the gels contemplates three basic elements: first, a fully or predominantly crystalline body (most preferably a glass-ceramic body) is formed which contains crystals consisting essentially of a lithium and/or sodium water-swelling mica selected from the group of fluorhectorite, hydroxyl hectorite, boron fluorphlogopite, hydroxyl boron phlogopite, and solid solutions among those and between those and other structurally-compatible species selected from the group of talc, fluortalc, polylithionite, fluorpolylithionite, phlogopite, and fluorphlogopite; second, that crystalline body is contacted with a polar liquid, customarily water, to cause swelling and disintegration of the body accompanied with the formation of a gel; and, third, the solid:liquid ratio of the gel is adjusted to a desired value depending upon the utility to which the final product is to be placed.
The crystals developed following the disclosure of U.S. Pat. No. 4,239,519 demonstrate a morphology of a continuum of flakes, rectangular-like strips, and interwoven ribbons in parallel or sub-parallel zones or sheaths with said flakes being irregularly shaped with diameters between about 0.5-10 microns and cross sections of less than 100 Å, and said strips and ribbons being about 0.5-10 microns long, about 500-5000 Å wide, and less than about 100 Å thick. That morphology yields crystals displaying a very high aspect ratio, higher than naturally-occurring mica, and large surface area, both of those characteristics rendering the materials useful for reinforcing various matrices.
Good chemical durability is endowed to the papers, fibers, films, boards, coatings, etc., prepared from the gels by contacting those products with a source of large cations to effect flocculation of the gel and an ion exchange reaction to occur between the large cations and the Li + and/or Na + ions from the interlayer of the crystals, and then washing and drying the resulting materials. The patent observed the utility of K + , Rb + , Cs + , Ag + , Cu + , NH 4 + , H 3 O + , Ca +2 , Sr +2 , Ba +2 , Pb +2 , and certain organic polycations, specifically reciting aniline hydrochloride and quaternary ammonium compounds as illustrative of operable large cations.
If desired, the ion exchange reaction may be carried out with the gel, i.e., before paper, fibers, films, boards, coatings, or other products are formed therefrom, or it may be conducted during the actual forming process for the product. However, no matter at what juncture the ion exchange reaction is undertaken, its occurrence is unequivocally required to prevent spontaneous degradation of the products in the presence of water.
Where products produced in accordance with that patent have been subjected to long term testing, it has been discovered that such physical properties thereof as mechanical strength, dielectric strength, loss tangent, and ionic conductivity are deleteriously affected by an atmosphere of high relative humidity. Thus, the physical characteristics exhibited by those products are not permanently stable in the presence of moisture.
U.S. application Ser. No. 461,672, filed concurrently herewith in the name of Shy-Hsien Wu under the title ORGANIC-INORGANIC COMPOSITES OF NEUTRALIZED POLYELECTROLYTE COMPLEXES now U.S. Pat. No. 4,455,382 and U.S application Ser. No. 461,571, also filed concurrently herewith in the names of S. N. Hoda and A. R. Olszewski under the title ORGANIC-INORGANIC COMPOSITES CONTAINING SYNTHETIC MICA, now U.S. Pat. No. 4,454,237 have for their objectives the development of means for rendering products produced in accordance with the method of U.S. Pat. No. 4,239,519 relatively insensitive to changes in relative humidity in the surrounding environment.
The basis of the first disclosure lies in the discovery that a neutralized polyelectrolyte complex can be prepared via the reaction of an anionic gel prepared in the manner described in U.S. Pat. No. 4,239,519 with an equivalent amount of an organic polycation. Such a complex, when formed into paper, fiber, film, board, or coating, displays exceptional toughness, excellent hydrophobicity, high mechanical strength, and good electrical properties. And, because of the resistance of the products to attack by moisture, the physical characteristics thereof are quite insensitive to variations in relative humidity of the atmospheres to which they are exposed. The exceptional hydrophobic character exhibited by the products of Ser. No. 461,672 is acquired through the formation of a strong polycation-polyanion interaction. Moreover, the long chain nature of a polycation imparts high strength and toughness to the composites, since the polycation can react with itself and/or with adjoining chains upon curing.
As is mentioned in Ser. No. 461,672 , ion exchange of an organic polycation with an anionic gel was cursorily alluded to in U.S. Pat. No. 4,239,519. Nevertheless, there was no teaching in the patent of the criticality for maintaining charge neutrality in the exchanged system. In contrast, charge neutrality comprises the very crux of the inventive materials disclosed in Ser. No. 461,672. That is, each of the exceptionally desirable chemical and physical properties exhibited by the inventive materials can be laid to the organic polycations reaction with an equivalent quantity of inorganic polyanions' (gels) to form a neutralized polyelectrolyte complex. In sum, any significant movement away from charge neutrality yields a polyelectrolyte complex system which is virtually of no practical utility because of its high sensitivity to deterioration in a moisture-laden environment.
The inventive method disclosed in Ser. No. 461,672 to produce paper, fiber, film, board, or coating involves six general steps:
(a) a fully or predominantly crystalline body is prepared according to the practice described in U.S. Pat. No. 4,239,519 and having an overall composition and microstructure as disclosed in that patent;
(b) that body is contacted with a polar liquid, customarily water, for a period of time sufficient to cause swelling and disintegration thereof accompanied with the formation of a gel having crystals dispersed therewithin;
(c) that gel is contacted with a source of organic polycations in an amount and for a time sufficient to cause an ion exchange reaction to take place between the organic polycations and the Li + and/or Na + ions from the interlayer of the above-noted crystals and to neutralize the charge density of those crystals, thereby promoting the formation of a neutralized polyelectrolyte complex;
(d) that complex, normally existing in the form of floc, is dispersed into a liquid selected from the group of polar organic liquids, aqueous NH 4 OH solutions, and aqueous salt solutions of large cations selected from the group of K + , Rb + , Cs + , Ag + , Cu + , NH 4 + , Ca +2 , Sr +2 , and Pb +2 ;
(e) the solid:liquid ratio of the complex and liquid is adjusted to a desired fluidity; and
(f) paper, fiber, film, board, or coating is prepared therefrom.
Formamide is noted as being the preferred organic liquid dispersing solution and aqueous solutions of KC1 and NH 4 OH as the preferred inorganic dispersants.
Ser. No. 461,672 discloses and describes three categories of organic cations which are operable in that invention, viz., N + , P + and S + . The most common of those is N + , of which there are four types:
(1) a primary amine solubilized with acid, exemplified by
R--NH.sub.3.sup.+ X.sup.- ;
(2) a secondary amine solubilized with acid, illustrated by ##STR1##
(3) a tertiary amine solubilized with acid, represented by ##STR2##
(4) a quaternary ammonium acid salt, designated by ##STR3## wherein the cationic characteristic increases from the primary amine up to the quaternary cation.
Illustrative of the P + cation is the quaternary phosphonium acid salt ##STR4##
The S + cation is represented by the ternary sulfonium acid salt ##STR5##
The most preferred source of organic polycations disclosed in Ser. No. 461,672 is stated to be KYMENE 557H solution, marketed by Hercules, Incorporated. That material is described as a cationic, water soluble condensate of a basic polyamide and epichlorohydrin which has assumed a polyamide-polyamine-epichlorohydrin resin form. Other operable polyquaternary ammonium salts cited in Ser. No. 461,672 include ACCOSTRENGTH 711, marketed by American Cyanamid Company, Wayne, N.J., and NALCOLYTE 7134, marketed by Nalco Chemical Company, Chicago, Ill.
The inventive method disclosed in Ser. No. 461,571 to produce composite articles of various geometries such as paper, fiber, film, board or coating utilizes five general steps:
(1) a fully or predominantly crystalline body is formed according to the method disclosed in U.S. Pat. No. 4,239,519 and having an overall composition and microstructure as defined in that patent;
(2) that body is contacted with a polar liquid, conveniently water, for a period of time sufficient to cause swelling and disintegration thereof accompanied with the production of a gel having crystals dispersed therewithin;
(3) that gel is contacted with a source of organic cations selected from the group of aminosilanes and organic chrome complexes in an amount and for a time sufficient to cause an ion exchange reaction to take place between said cations and Li + and/or Na + ions from the interlayer of said crystals;
(4) the solid:liquid ratio of the exchanged gel and the liquid is adjusted to a desired fluidity; and
(5) paper, fiber, film, board, or coating is prepared therefrom.
Ser. No. 461,571 discloses Z6020, N-β-aminoethyl-γ-aminopropyl trimethoxy silane, marketed by Dow Corning Corporation, Midland, Mich., as illustrative of an operable aminosilane, and teaches suitable organic chrome complexes as being selected from the group of a chemically reactive Werner complex, methacrylato chromic chloride, wherein methacrylic acid is coordinated with chromium (VOLAN), and a chemically reactive Werner complex wherein a C 14 -C 18 fatty acid is coordinated with trivalent chromium (QUILON C), both marketed by E. I. DuPont de Nemours & Co., Wilmington, Del.
U.S. Pat. No. 4,239,519 is primarily concerned with the use of glass-ceramics as starting materials for producing crystal-containing gels. Several other means for producing operable starting materials are available, however.
For example, "Fluorine Micas", Bureau of Mines Bulletin 647, pages 236-242 (1969) describes sintering and recrystallizing a batch composed of raw materials such as talc, silica, magnesia, and fluoride in the proper proportions to form water-swelling fluormicas that can be utilized to make inorganic paper.
As an alternative to that simple reaction sintering practice, a synthetic lithium and/or sodium water-swelling, gel-forming material can be prepared by firing a batch of a predetermined composition in an autoclave. As illustrative of that technique, a lithium fluormica can be produced by hydrothermally treating a batch compounded from talc, a source of silica such as silicic acid or powdered silica, lithium silicate, magnesia, lithia, and fluorides of lithium, magnesium, or ammonium in the proper proportions to yield the stoichiometry of the desired lithium fluormica.
In yet another method, magnesium and silica-containing species are co-precipitated in the presence of Li + , Na + , and F - ions and that precipitate subjected to a hydrothermal treatment. In a variation of that technique, SiO 2 is precipitated into a preformed aqueous suspension of a water insoluble magnesium compound. That mass is then subjected to a hydrothermal treatment in the presence of excess lithium or sodium compounds.
As can be observed, each of those methods requires the batch constituents to be present in such amounts that the reaction product will approximate a desired stiochiometry.
SUMMARY OF THE INVENTION
We have found that, by modifying the processes disclosed in Ser. No. 461,672 and Ser. No. 461,571, a binder system can be developed for fabricating articles formed from inorganic and/or organic fibers such that the resulting products demonstrate relatively high mechanical strength when exposed to atmospheres of low and high relative humidity along with exceptional heat stability where inorganic fibers are employed. In essence, the inventive binder system demands the presence of two basic materials:
(a) a lithium and/or sodium water-swelling mica selected from the group of fluorhectorite, hydroxyl hectorite, boron fluorphlogopite, hydroxyl boron phlogopite, and solid solutions among those and between those and other structurally-compatible species selected from the group of talc, fluortalc, polylithionite, fluorpolylithionite, phlogopite, and fluorphlogopite; and
(b) a source of organic polycations, aminosilanes, and/or organic chrome complexes.
Whereas glass-ceramics prepared in accordance with the disclosure of U.S. Pat. No. 4,239,519 are deemed to constitute the preferred starting materials because of the inherent capability of the glass-ceramic process for carefully controlling the microstructure and crystal identity of the body plus obtaining crystals of relatively uniform signs, the inventive binder system is operable with any synthetic lithium or sodium water-swelling mica of the type described above in paragraph (a).
The organic polycations disclosed in Ser. No. 461,672 are quite suitable in the present invention. Thus, organic polycations operable in the present invention are selected from the group of:
(1) a primary amine solubilized with acid;
(2) a secondary amine solubilized with acid;
(3) a tertiary amine solubilized with acid;
(4) a quaternary ammonium acid salt;
(5) a quaternary phosphonium acid salt; and
(6) a ternary sulfonium acid salt.
For a more complete discussion of those organic polycations, attention is directed to Ser. No. 461,672, the disclosure of which is incorporated herein by reference.
In like manner, the aminosilanes and organic chrome complexes described in Ser. No. 461,571 are operable in the present inventive method and the disclosure of that application is also specifically incorporated herein by reference.
In general, the starting materials will consist essentially, expressed in terms of weight percent on the oxide basis, of
Li 2 O:0-12
Na 2 O:0-10
Li 2 O+Na 2 O:0.5-14
MgO: 10-38
B 2 O 3 :0-30
Al 2 O 3 :0-10
SiO 2 :35-70
F:0-15
OH:0-15
F+OH:4-15
with the preferred compositions consisting essentially of
Li 2 O:0.5-12
Na 2 O:0-10
Li 2 O+Na 2 O:0.5-14
MgO:14-38
B 2 O 3 :0-15
Al 2 O 3 :0-10
SiO 2 :35-70
F:5-15
The inventive process preferably comprehends the following required and optional steps:
(a) a crystal-containing body is formed wherein said crystals consist essentially of a lithium and/or sodium water-swelling mica selected from the group of fluorhectorite, hydroxyl hectorite, boron fluorphlogopite, hydroxyl boron phlogopite, and solid solutions among those and between those and other structurally-compatible species selected from the group of talc, fluortalc, polylithionite, fluorpolylithionite, phlogopite, and fluorphlogopite;
(b) said body is contacted with a polar liquid for a time sufficient to cause swelling and disintegration thereof accompanied with the formation of a gel;
(c) organic and/or inorganic fibers inert to said polar liquid are dispersed in a quantity of said polar liquid or another polar liquid which is miscible with said polar liquid;
(d) either said gel or an ion exchangeable compound selected from the group of an organic polycation, an aminosilane, and an organic chrome complex or a mixture of said gel and said ion exchangeable compound is blended into said dispersion of fibers;
(e) where a mixture of said gel and said ion exchangeable compound was not blended into said dispersion of fibers in Step (d), either said gel or said ion exchangeable compound, whichever ingredient was not blended into said dispersion of fibers in Step (d) is blended into said dispersion of fibers, the combination of said gel and said ion exchangeable compound causing an ion exchange reaction to take place between the interlayer Li + and/or Na + ions in the crystals of said gel and cations from said ion exchangeable compound resulting in a reaction product of a floc;
(f) excess liquid is removed from said fiber/floc dispersion to yield a wet mass;
(g) said wet mass is optionally washed;
(h) said wet mass is dried and cured.
Drying and curing are conveniently undertaken in air, care being taken to essentially completely dry the mass at temperatures sufficiently low to avoid the development of bubbles prior to curing the mass. Curing will be conducted at temperatures below the degradation temperature of the ion exchangeable compound. Normally, satisfactory curing can be secured at temperatures no higher than 150° C.
Inasmuch as the flocs are formed in the presence of the fibers, fiber entanglement occurs and what has been termed fiber/floc agglomerates are produced. A high percentage of the binder is retained in the entangled fibers.
The fiber/floc mixture will be dispersed into a body of a predetermined geometry. For example, the fiber/floc mixture may be drained on a screen to form a mat. Where desired, that mat may be pressed to a denser state and excess liquid may be removed utilizing a vacuum. Boards, tiles, etc., can be fashioned from the mat. Other body configurations amenable to formation through conventional ceramic product forming techniques are possible. This embodiment of the inventive method is especially adaptable to the continuous production of sheet utilizing the wellknown Fourdrinier process.
In another embodiment of the general inventive method, a wet mass of fibers in polar liquid is formed and gel is brought into contact with that mass to impregnate it, the crystals in the gel forming a coating on the fibers. After removing excess liquid, the ion exchangeable compound is brought into contact with the gel-impregnated mass to impregnate it and cause the ion exchange reaction to occur. The doubly impregnated mass can be optionally washed and then dried and cured.
This sequence of steps is quite applicable for the production of flat articles, such as tile, but lacks flexibility in shaping more complex configurations. Furthermore, the method is not readily amenable to the continuous production of sheet as, for example, utilizing the Fourdrinier process.
However, because the ion exchange reaction is carried out directly at the site of application, viz., in the presence of the fibers, good bonding of the fibers is secured which leads to a final product demonstrating high mechanical strength.
As is described above in the description of the overall general method, it is possible to mix the gel and ion exchangeable compound (forming a floc) and then blend that mixture into the dispersion of fibers. After optionally washing the mass resulting from the fiber/floc dispersion, it can be dried and cured.
The sequence of steps in this embodiment of the inventive method allows great flexibility in the shaping of final products of widely-varying configurations, including the use of the Fourdrinier process for forming sheet. Nevertheless, because the ion exchange reaction is not carried out in situ in the presence of the fibers, the final products resulting therefrom do not have quite the mechanical strength and thermal stability exhibited by articles prepared in accordance with the first two above-described embodiments of the invention.
In order to insure good bonding of the fibers with the consequent production of a strong final product, at least about 5% by weight of binder will be present. Very high loadings of binder may be incorporated but to no practical advantage, and greatly increase the cost of the product. Accordingly, loadings of about 10-20% are preferred.
The invention will now be described by means of the following working examples which must be deemed illustrative only of the inventive process and in no way limiting.
DESCRIPTION OF PREFERRED EMBODIMENTS
In Examples 1 and 2, a glass-ceramic body having a composition approximating Example 14 of U.S. Pat. No. 4,239,519 (the preferred composition of that patent) was utilized as a starting material. In preparing that glass-ceramic, a glass body having the following approximate composition, expressed in terms of weight percent on the oxide basis as calculated from the batch, of
SiO 2 :64.5
MgO:10.8
Li 2 O:8.0
MgF 2 :16.7
was exposed to a temperature of about 700° C. for about four hours to yield a highly crystalline article containing very uniformly-sized lithium fluorhectorite as the predominant crystal phase.
KYMENE 557H was found to be the preferred source of organic polycations and, hence, was utilized in the examples. Nevertheless, it will be appreciated that the other organic cations disclosed in Ser. Nos. 461,672 and 461,571 are also operable.
Finally, whereas organic and inorganic fibers of all types can be operable in the inventive process, cellulose fibers and mineral wool are especially desirable in yielding a very strong final product. Although the mechanism acting to impart the greater strength is not fully understood, it is believed that the organic polycations react with the cellulose fibers and mineral wool to improve the bonding and thereby enhance the mechanical strength of the product. Mineral wool was employed in each of the following examples since it imparts higher use temperature capability to a product than does the incorporation of cellulose fibers. Mineral wool is a frequent component in ceiling and acoustic tile.
EXAMPLE 1
160 grams of mineral wool were dispersed into 7 liters of deionized water and mixed thoroughly for 2 minutes. 240grams of 3 % KYMENE 557 H solution (7.2 grams dry solids) were added to the slurry and mixed thoroughly for 1 minute. 192 grams of gel (7.5% solids solution--14.4 grams dry solids), prepared by immersing the above-described glass-ceramic into water, were charged into the slurry and thoroughly mixed for 2 minutes.
The slurry was poured onto a No. 100 United States Standard Sieve (149 microns) and allowed to drain therethrough. A vacuum was subsequently applied for 2 minutes to draw off the excess water. A tile having a thickness of about 2.3 cm was formed which was thereafter air dried and cured in a heating chamber utilizing the following schedule:
Overnight at 60°0 C.
1 hour at 80° C.
1 hour at 100° C.
2 hours at 120° C.
The tiles demonstrated an average modulus of rupture at ambient temperature and 50% relative humidity of about 180 psi, and a modulus of rupture at 40° C. and 80% relative humidity of about 110 psi. Whereas the tiles manifested some decrease in mechanical strength at the higher temperature and humidity levels, the values are above the minimum strengths demanded for many applications (e.g., 100 psi for ceiling tiles).
EXAMPLE 2
160 grams of mineral wool were dispersed into 7 liters of deionized water and mixed thoroughly for 4 minutes. The slurry was poured onto a No. 100 United States Standard Sieve, allowed to drain, the top surface thereof gently patted with a flat plate to render it smooth and level, and a vacuum applied for 1 minute to draw off the excess water, thereby forming a fibrous mat.
710 grams of gel (7.5% solids solution--53.3 grams dry solids), prepared by immersing the above-described glass-ceramic into water, were poured onto the fibrous mat and allowed to rest upon and soak therein for 2 minute. A vacuum was applied for 1 minute to draw the gel through the mat.
950 grams of 6% KYMENE 557H solution (57 grams dry solids) were poured onto the mat and permitted to rest upon and soak therein for 5 minutes. The impregnation of the mat by the gel was advanced by applying a vacuum for 3 seconds and then allowing the mat to rest for 1 minute. That sequence was repeated. After the second 1-minute rest, the vacuum was applied for 2 minutes and the mat then permitted to be at rest for the final 1 minute. A tile having a thickness of about 1.5 cm was found.
The following procedure was employed to rinse the tile:
500 ml deionized water were poured onto the mat.
A vacuum was applied for 30 seconds.
The above sequence of steps was repeated 6 times.
A vacuum was applied for 2 minutes.
The tiles were air dried as above in Example 1. The final bodies exhibited an average modulus of rupture at ambient temperature and 50% relative humidity of about 220 psi, and a modulus of rupture at 40° C. and 80% relative humidity of about 150 psi. It is quite evident that the mechanical strengths of the instant products exceed the conventional minima.
As has been discussed above, articles can be formed by blending the gel and KYMENE solution together to produce floc and the mat then impregnated with the floc. However, the strength demonstrated by such articles has commonly been found to be somewhat less than when the gel and KYMENE solution are applied seriatim to the fibrous mat. The reason for this apparent lower strength has not been fully elucidated. It has been conjectured that impregnating the mat with floc results in simple mechanical intertwining of the floc and fibers whereas, when flocculation is carried out in situ among the fibers, the floc tends to coagulate around the fibers, thereby providing a stronger bond. It must also be appreciated that KYMENE polymerizes with hydroxyl groups. Cellulose has available OH - groups . Accordingly, KYMENE can bond directly to cellulose fibers.
Tiles were formed therefrom following the process described above in Example 1 utilizing mineral wool as the fiber component and ion exchanging the above synthetic mica with a 3% KYMENE 557H solution to form the binder, the binder being present in an amount of about 13% by weight. The tiles exhibited an average modulus of rupture of 326 psi at ambient temperature and 50% relative humidity and an average modulus of rupture of 246 psi at 38° C. and 80% relative humidity.
As can be observed, there is a sharp decrease in mechanical strength (˜25%) evidenced when these tiles were exposed to higher temperatures and humidities. Nonetheless, the final value is well above the minimum 100 psi discussed above.
EXAMPLE 3
A batch consisting of 10.9 parts by weight SiO 2 , 24 parts by weight talc, 14.2 parts by weight MgSiF 6 ·6H 2 O, and 13.1 parts by weight LiOH·H 2 O was compounded and fired to sintering. The sintered material had a composition approximating the stoichiometry of LiMg 2 LiSi 4 O 10 F 2 ·(0.25)LiF. Upon immersion into water, a gelatinous suspension formed containing about 10% by weight solids which was filtered through a No. 200 United States Standard Sieve (74 microns) to remove impurities.
EXAMPLE 4
A batch consisting of 11.4 parts by weight of SiO 2 , 20.3 parts by weight of talc, 22.8 parts by weight of MgSiF 6 ·6H 2 O, and 21 parts by weight of LiOH·H 2 O was compounded and sintered to yield a material having a stoichiometry approximating (LiF) (LiMg 2 LiSi 4 O 10 F 2 ). Tiles were made therefrom in the manner described in Example 1 again utilizing mineral wool as the fiber component and ion exchanging the above synthetic mica with a KYMENE 557H solution to serve as the binder, the binder being included in an amount of about 9.8% by weight. The tiles demonstrated an average modulus of rupture of 450 psi at ambient temperature and 50% relative humidity and 254 psi at 38° C. and 80% relative humidity.
As can be observed from the above examples, the method employed to prepare the synthetic water-swelling mica is not a primary factor to be considered in producing articles in accordance with the instant invention. Nevertheless, the method utilized may impact significantly the final physical characteristics of the products because of effects which the synthetic processing may have upon the properties of the synthetic mica. However, the formation of the strong bonding medium is the result of the ion exchange reaction taking place between the synthetic water-swelling mica particles and the organic polycations, an aminosilane, and/or organic chrome complex. The overall effectiveness of the bond is determined by the morphology, size, and layer charge of the synthetic mica, along with the hydrophobicity of the binder materials.
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The present invention is directed to the production of articles exhibiting high mechanical strengths which are relatively insensitive to changes in relative humidity. The articles consist essentially of organic and/or inorganic fibers and a binder, the binder being composed of the product of reaction between an organic polycation, and/or an aminosilane, and/or an organic chrome complex and crystals of a lithium and/or sodium water-swelling mica selected from the group of fluorhectorite, hydroxyl hectorite, boron fluorphlogopite, hydroxyl boron phlogopite, and solid solutions among those and between those and other structurally-compatible species selected from the group of talc, fluortalc, polylithionite, fluorpolythionite, phlogopite, and fluorphlogopite.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 13/466,301 entitled “Connection Mechanism”, filed May 8, 2012. The entire contents of the above mentioned application are hereby specifically incorporated by reference in their entirety.
BACKGROUND
[0002] Portable electronic devices are ubiquitous. For example, Global Positioning System (GPS) receivers and mapping devices are found as standalone devices or incorporated into mobile telephones or other devices. Many people carry tablet or slate computers for accessing the Internet or for running various applications.
[0003] In many cases, users of these devices carry the devices in their pockets, but there are many instances where a user may wish to attach the device to a dashboard in a car, handlebars of a bicycle, a golf cart, or any other application.
SUMMARY
[0004] A connection mechanism between two components may use one or more metallic pins that are magnetically extended when the components are engaged, and a sloped groove that retracts and unlocks the pins when the components are rotated. The components are locked in place by the pins during engagement. Disengagement may be performed by rotating the two components with respect to each other. The connection mechanism may include one or more magnets mounted on either or both components. The magnets may be arranged to attract the components when the components are in the locking orientation and to repel the components when the components are rotated to an unlocked position. The connection mechanism may include electrical connections between the components.
[0005] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] In the drawings,
[0007] FIG. 1 is a diagram illustration of an embodiment showing two connection components.
[0008] FIG. 2A is a schematic illustration of a pair of connection components in a first position.
[0009] FIG. 2B is a schematic illustration of a pair of connection components in a second position.
[0010] FIG. 2C is a schematic illustration of a pair of connection components in a third position.
[0011] FIG. 3 is a diagram illustration of an embodiment showing the connection components being used for mounting a mobile telephone.
DETAILED DESCRIPTION
[0012] A connection mechanism or coupler may use metallic pins that are normally retracted into a first component, but may extend into a slot in a second component by magnetic attraction. The slot may be configured so that when the components may be rotated with respect to each other, the pin may be moved back to its refracted position. When retracted, the components may be separated, but when the pin is engaged in the slot, the components may be held together.
[0013] The components may engage each other in different sequences. In one sequence, the components may be mated but may be rotated with respect to each other, such that the pin or pins do not align with the slot. As the components are rotated to the locking position, the pins may extend. The components may be unlocked by rotating the components with respect to each other.
[0014] In a second sequence, the components may be mated such that the pin or pins are aligned with the slots. As the components are mated, the pins may be extended and the components may be locked in place. As with the previous sequence, the components may be unlocked by rotating the components with respect to each other.
[0015] Some embodiments may include one or more engagement magnets that may attract the components together. In some such embodiments, the engagement magnets may be arrayed such that they attract the components in a locked position but repel the components in an unlocked position. Such embodiments may give a user a tactile feedback when the components are unlocked and locked.
[0016] The connection mechanism may mechanically lock the components together, but may be readily separated by rotating the components. In the locked position, the connection mechanism may transmit forces from one component to the other component.
[0017] In some embodiments, the components may also include various connections, such as electrical connections, air or gas connections, liquid connections, or other connections. With access flow or integration points between the components, such embodiments may be useful for connecting various electrical signals, hoses, pipes, or other conduits in an easy to install and easy to remove system.
[0018] Throughout this specification, like reference numbers signify the same elements throughout the description of the figures.
[0019] When elements are referred to as being “connected” or “coupled,” the elements can be directly connected or coupled together or one or more intervening elements may also be present. In contrast, when elements are referred to as being “directly connected” or “directly coupled,” there are no intervening elements present.
[0020] FIG. 1 is a schematic illustration of an embodiment 100 showing a first and second component. FIG. 1 is not to scale. Embodiment 100 illustrates an example of a mating pair of components oriented so that the mating surfaces are shown.
[0021] Embodiment 100 illustrates a first component 102 and second component 104 oriented to view the mating surfaces 126 and 154 . When the first component 102 is engaged to the second component 104 , the first component 102 may be flipped over such that the mating surfaces 126 and 154 are touching each other.
[0022] Embodiment 100 illustrates an example of a mating pair of components that may be locked in one of four positions. Each of the four locking positions may be 90 degrees from the next. Other embodiments may have one, two, three, four, five, six, or more locking positions.
[0023] The first component 102 has a set of pins 106 , 108 , 110 , and 112 that may correspond to the slots 128 and 130 of the second component. The second component may have additional slots that are not shown. The slots 128 and 130 may form lips 132 and 134 . When the first component 102 is engaged to the second component 104 , the various pins may extend into the slots of the second component 104 , thereby locking the two components together.
[0024] The pins on the first component 102 may be drawn into the slots of the second component 104 by magnets 136 , 138 , 140 , and 142 that may be positioned near the slots. As the two components are engaged, the magnets 136 , 138 , 140 , and 142 may magnetically attract the pins from their retracted position and into an extended position. In the extended position, the pins may extend into the slots and the first component 102 may be locked to the second component 104 . The magnets 136 , 138 , 140 , and 142 may be located inside the second component 104 but near the various slots.
[0025] The slots may be constructed so that when the first component 102 is rotated with respect to the second component 104 , the pins may be forced back into the refracted position. When in the retracted position, the two components may be separated from each other.
[0026] Embodiment 100 shows locking positions that may be equally positioned around the primary axes 156 and 158 . Embodiment 100 further illustrates an embodiment where each pin may be engaged into a corresponding slot in the mating component. Other embodiments may have the various pins and slots located such that one or more of the locking positions may not engage all of the various pins and slots.
[0027] In one such type of embodiment, the second component 104 may have more slots than the first component has pins. In another type, the first component 102 may have more pins than the second component 104 has slots. In still another type, the orientation and position of the various pins and slots may be such that not all of the pins may be engaged into slots in a locking position.
[0028] The various pins 106 , 108 , 110 , and 112 are illustrated as rectangular bars. The pins may be formed in many different shapes and move in various manners in other embodiments. For example, the pins may have a circular, square, or other shaped cross-section.
[0029] In the example of embodiment 100 , the pins may move linearly. Other embodiments may use pins that rotate about a hinge point or slide in a curved fashion.
[0030] Embodiment 100 shows pins that move in a channel or hole that is perpendicular to the primary axis 156 . Other embodiments may have a similar channel or hole, but that channel or hole may not be perpendicular to the primary axis 156 .
[0031] The first component 102 has an engagement face 124 that is circular in shape which is a revolved surface about the primary axis 156 . The engagement face 124 may fit against the engagement face 152 of the second component 104 when the two components are mated. The engagement face 152 of the second component 104 may be a revolved surface about the primary axis 158 .
[0032] The engagement face 124 of the first component 102 may be slightly smaller in diameter than the engagement face 152 of the second component 104 . The difference in diameters may vary with different embodiments. In some embodiments, the diameter difference may be on the order of a slip fit, which may be 0.005 in to 0.020 in in some cases. Some embodiments may have a diameter difference of 0.020 in to 0.050 in or larger.
[0033] The engagement faces 124 and 152 are illustrated as being complete circles. With the arrangement of the pins and slots, embodiment 100 is an example embodiment where the two components 102 and 104 may be rotated 360 degrees with respect to each other.
[0034] In some embodiments, the engagement faces 124 and 152 may be sectors of circles and the embodiments may permit the components to rotate only a limited arc with respect to each other. Such embodiments may permit only one, two, three, four, or more locking positions, but may not allow the components to rotate more than the limited arc when the mating surface 126 of the first component 102 is in contact with the mating surface 154 of the second component.
[0035] The two components 102 and 104 are illustrated as being outfitted with some engagement magnets. The first component 102 is illustrated as having magnets 114 , 116 , 118 and 120 , while the second component 104 is illustrated as having magnets 144 , 146 , 148 , and 150 . The engagement magnets may be exposed or located below the surface of the various components.
[0036] The various engagement magnets may draw the two components together when the components are in a locked position. The polarity of the magnets may be selected so that when the components are rotated to an unlocked position, the engagement magnets may repel each other, causing the components to repel.
[0037] The engagement magnets are illustrated as being placed in groups of three. In such an arrangement, the center magnet may have a different polarity than the two other magnets. The corresponding set of magnets on the opposite component may be arranged similarly, but so that the sets of magnets attract when the components are in the locking position.
[0038] The position and arrangement of the engagement magnets in embodiment 100 is merely one example of many different placements of engagement magnets. Embodiment 100 illustrates the engagement magnets within the periphery of the engagement faces, but other embodiments may have engagement magnets located outside of the radius of the engagement faces.
[0039] Embodiment 100 further illustrates an example embodiment where electrical connections may be made when the two components are engaged. The first component 102 may have several concentric electrical contacts 122 that may mate with the electrical contacts 160 of the second component 104 .
[0040] The electrical contacts 160 may be spring loaded contacts that may slide along the concentric electrical contacts 122 when a user couples and decouples the components. Other embodiments may have other connections, such as hose connections that may pass gasses or liquids through the components. Such hose connections may be passed through the center of the components along the primary axis is some embodiments. Some embodiments may pass light, including laser light, through the components.
[0041] FIGS. 2A , 2 B, and 2 C illustrate embodiments 202 , 204 , and 206 showing three different positions of a first component 208 and a second component 210 . Embodiments 202 , 204 , and 206 are schematic illustrations of how the components move from an unlocked position to a locked position and are not to scale.
[0042] Embodiment 202 illustrates the components in an unlocked position. Embodiment 206 illustrates the components in a locked position, and embodiment 204 shows the components in between locked and unlocked.
[0043] The locking sequence may be seen by viewing the embodiments in order from top to bottom. The unlocking sequence operates in reverse.
[0044] In the first position shown in embodiment 202 , the first component 208 is rotated with respect to the second component 210 such that the pin 216 is illustrated as being away from the slot 214 . The pin 216 is illustrated in a retracted position within the channel 218 .
[0045] As the first component 208 is rotated as shown in embodiment 204 , the magnetic attraction of the magnet 212 may draw the pin 216 out of the channel 218 and into the slot 214 .
[0046] When the first component 208 reaches a locked position as shown in embodiment 206 , the pin 216 may be fully extended into the slot 214 . The pin 216 may be extended to the locking position by the magnetic attraction provided by the magnet 212 . When in the locked position, the pin may engage a lip formed by the slot and thereby mechanically restrict the components from being pulled apart.
[0047] In many devices, a set of engagement magnets (not shown) may help hold the two components in the locked position.
[0048] In order to unlock the components, the first component 208 may be rotated to the position shown in embodiment 204 . As the first component 208 is rotated, the slot 214 may force the pin 216 to retract into the channel 218 .
[0049] As the unlocking process continues, the first component 208 may be further rotated to the position shown in embodiment 202 . As the first component 208 is further rotated, the slot 214 may force the pin 216 further into the channel 218 and into a refracted position.
[0050] FIG. 3 is an illustration of an embodiment 300 showing a mechanical coupler used to mount a mobile phone. FIG. 3 is not to scale.
[0051] The mechanical coupler may be used in many different applications. In merely one example of such a use, the coupler may be used to mount a mobile telephone to a holder. The holder may be, for example, mounted on a bicycle handlebar, automobile dashboard, or some other location. The mobile telephone may be mounted in a removable case that includes the mating coupler component so that the mobile telephone may be quickly mounted and removed.
[0052] In the example of embodiment 300 , the first component 302 may be mounted to a mobile phone case 310 . The second component 304 may be mounted to a stand or other mechanism.
[0053] The first component 302 is illustrated with pins 306 and 308 , as well as electrical contacts 312 . Embodiment 300 may provide electrical power and signal connections between the stand (not shown) to which the second component 304 is attached, to the mobile phone held in the case 310 .
[0054] The foregoing description of the subject matter has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the subject matter 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 except insofar as limited by the prior art.
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A connection mechanism between two components may use one or more metallic pins that are magnetically extended when the components are engaged, and a sloped groove that retracts and unlocks the pins when the components are rotated. The components are locked in place by the pins during engagement. Disengagement may be performed by rotating the two components with respect to each other. The connection mechanism may include one or more magnets mounted on either or both components. The magnets may be arranged to attract the components when the components are in the locking orientation and to repel the components when the components are rotated to an unlocked position. The connection mechanism may include electrical connections between the components.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention in general relates to a prime mover based upon a centrifugal reverse flow disk turbine, which is applicable to steam, gas, water, and air turbines, and a method to yield a rotational power thereby.
2. Related Art
In conventional turbines, which have been operated in fossil and nuclear power plants, for example, large-scale steam (water) turbines more than one gigawatt (GW) under a supercritical condition are utilized in order to minimize the steam rate and to improve the thermal efficiency thereof.
However, it is estimated that these fossil and nuclear fuels on the earth would run out at end of this century as clearly projected in FIG. 11 . FIG. 11 includes all kind of energy resources on the earth, i.e. fossil fuels (oil, coal, and natural gas), and nuclear fuel, as well as methane hydrate therewith.
Another crucial issue human beings are now facing with is global warming due to carbon dioxide (CO 2 ) emissions into earth's thin planetary boundary layer, mainly caused by combustion of fossil fuels as mentioned above. The British government's chief scientific adviser, Sir David King, has described global warming as a greater threat than terrorism. (The Japan Times, Feb. 4, 2005)
According to a recent super-computer projection (Saitoh and Wakashima, Green Life, Mar. 2006), as indicated in FIG. 10 , the CO 2 concentration in the atmosphere will increase to 1250 ppmv within 100˜200 years as in FIG. 12 . What is the most outstanding feature of our simulations is that after taking a maximum, the CO 2 concentration will stay almost constant during 50000 years thereafter.
While, urban environment in mega-cities like Tokyo is still getting worse and worse. For example, the concentration of NO 2 is still increasing and above a regulated level in the Tokyo metropolitan area. The cause of aggravation of the urban environment can be mainly attributed to increase of automobiles in the urban area. This serious environmental issue is called “urban warming (or heat island)”, which is caused by a concentrated consumption of energy in the urban area.
These two major restrictions oblige human to change their life styles and use renewable energies including solar, wind, ocean, geothermal, and biomass, other than fossil fuels.
However, the renewable energy is dispersed and attainable temperature and pressure are sometimes low, thereby leading to a down-sized prime mover. This down-sizing brings conventional turbine a great aggravation of thermal efficiency illustrated clearly in FIG. 13 .
Further, multi-staging and reheating/regenerating cycles, which have been very common in conventional large-steam turbines could not be exploited in a small turbine because of a strict cost limitation.
A typical conventional large-scale steam turbine is of axial flow one having three-dimensional static and moving blades mounted on the housing and the rotor, respectively. The working fluid (for ex. water steam), in general, flows axially, so that the physical properties of steam may considerably change on its way to the last stage, thereby bringing the rotor diameter variation.
This causes complicatedness and high cost of a entire system (about 100˜500 times higher than conventional gasoline engine and the same power rated engines). This fact greatly hinders market permeation of the small-sized turbines.
In above-mentioned large-scale steam turbines, a supercritical condition (a condition exceeding pressure: 22.12 MPa, and temperature: 375.15 degree Celsius for water vapor) was adopted to raise its thermal efficiency. Nonetheless, the thermal efficiency of even the latest most advanced fossil-powered steam turbine is at most 40˜42%, this value being only 60% of the ideal Carnot cycle efficiency.
If the conventional steam turbine were down-sized to 10 kW, say, the thermal efficiency would be reduced to only 3˜5%, which is by far less than average photovoltaic cell efficiency (about 10%; annual mean).
[Tesla's Pioneering Works on Bladeless Disk Turbine]
Nikola Tesla (1857-1943), who was a US electric engineer, known as an inventor of induction motor, alternating current, Tesla coil, and magnifying transmitter, etc., conducted an intensive work on his Tesla bladeless turbine during the period from 1908 to 1930. Examples of his invention are seen in many prior art patents, including U.S. Pat. No. 1,061,142 and U.S. Pat. No. 1,061,206.
In the disk turbine, which bears his name, the rotor is composed of a plurality of flat plates which are set in motion through the adhesive and viscous action of the working fluid, entering the system tangentially at the periphery and leaving it at the center. At that time, the Tesla's turbine was spotlighted as a thermodynamic transformer of an actively surprising by far that of any other prime mover theretofore.
Around 1910, Tesla built his 200 horsepower turbine with rotor diameter of 18 inches, which turned at a speed of 9000 revolutions per minute. This turbine was situated in the Waterside Station, the main powerhouse of the New York Edison Company.
However, at his time, the trend was rapidly changing toward another type of turbines; i.e. Parsons and Curtis turbines, these were well entrenched in the development stage. As the history shows, these axial flow turbines have swept over the world thereafter. Tesla was a late starter. Had Tesla advanced with the development of his turbine as early as 1889 when he returned from the Westinghouse plant, the Tesla turbine might perhaps have been completed. This was really a turning point for the Tesla turbine.
However, mankind is now facing an unprecedented environmental age; namely, global warming due to CO 2 emissions, urban warming due to heat emissions in city area, exhaustion of fossil and nuclear fuels, problems of population growth, food production, drinking water scarcity, and other resources. In order to resolve all crucial issues stated above, exploitation of renewable energies such as solar, wind, geothermal, ocean thermal, biomass, various kinds of temperature differences etc. is inevitable and some of those have been partly introduced in the market. A Green New Deal Plan also comes up with by the Obama cabinet, last year.
With a tailwind of time and recent advancement of materials, and cutting-edge manufacturing technology, and computer simulation technique, as well as numerical methods involved, a sophisticated and highly-advanced version of Tesla turbine is brought back to life in a long absence of 100 years. In this sense, Tesla was a prodigal genius who dreamed and projected the future.
Advanced technologies such as multi-staging and reheating/regenerating cycles, which have been very common in conventional large-steam turbines, could not be exploited anymore in a small turbine because of a strict cost limitation. Instead, the present invention based on Tesla turbine having the great advantages of i) simplicity of design, ii) low noise and vibration level, iii) stability in operation, easy maintenance, iv) economies of construction, and lastly, v) very high-efficiency will reign over the world in the 21 st century.
It is especially noted here that without Tesla's pathfinding and profound original works, the present invention could not be accomplished at all.
As an important measure for evaluating all kinds on prime movers which will appear in the 21 st century, the most appropriate one will be the Carnot efficiency ratio (abbreviated as CER thereafter), this being a ratio of the real prime mover (engine) against the Carnot efficiency, that implies a maximum attainable limit among all kinds of prime movers ever appeared in the history or will appear in the future.
The Carnot efficiency ratios for typical engines and prime movers are illustratively plotted in FIG. 13 , including Gasoline engine (TOYOTA Prius), Diesel engine, Gas turbine, Steam turbine, Scroll engine, Gas engine, Vane-type engine, Stirling engine, and recent Fuel cell. It is again noted that the thermal efficiency is about twice better than conventional gasoline engine (see Prius in FIG. 13 ).
[Prius]
Since the great invention of gasoline-powered vehicle by Gottlieb Daimler and Karl Benz, almost simultaneously, in 1886, the gasoline engines have been widely accepted and swept over the whole world more than a century. Further, those engines are still dominating the world.
Although its reliability and cost effectiveness are overwhelming, efforts toward an improvement of the thermal efficiency of the gasoline engine is strictly limited owing to an old cycle of the engine, i.e. the Otto cycle. This engine could not survive any more in the environment-compatible 21 st century.
Evaluating the Prius (first manufactured in 1997 by TOYOTA) which has the best thermal efficiency (as a gasoline engine vehicle) in the world, one can judge whether the Prius would be earth-compatible or not. For example, the Carnot efficiency ratio (CER) of the Prius is only 0.44, thereby indicating a low compatibility against the environment.
Spencer Abraham, who was the Administrator of Energy Agency of Clinton Cabinet, estimated that the number of cars in 2050 would be 3.5 Billions. If this projection were true, and the business would go as usual, the energy consumption by cars would amount to about 9 TW (terawatts), this being more than a half of the current consumptions.
The Prius can curtail the fuel consumption to a half, however, this is not sufficient to mitigate global warming at all, since the energy consumption by cars will exceeds 16 TW even if all vehicles were replaced with the hybrids equivalent with the Prius.
[Fuel Cell]
As a next generation prime mover, fuel cell has been spotlighted and many automobile manufacturers placed much attention upon this promising future technology.
However, the fuel cell has three major crucial problems, which can not be solved easily; one is the energy resource. The fuel cell uses gaseous hydrogen, but hydrogen does not exist in nature as it is. It must be reformed from existing fossil fuels or by virtue of electrolysis from water by utilizing electricity via e.g. photovoltaic cell which is a carbon-free energy source. However, total transforming efficiency of solar to hydrogen route is very low, say, 3˜5% at maximum.
Secondly, the energy transforming efficiency of the fuel cell is relatively low; a theoretical efficiency reaches over 50%, but the auxiliary power needs at least 7% of generated electricity, thereby reducing the net power from the fuel cell. Current efficiency is around 40%, which is almost equal to the Prius' efficiency.
Lastly, life expectancy and cost itself; since the fuel cell involves a chemical reaction process, degradation such as membrane is inevitable, thereby reducing its life expectancy. Also considered as another crucial barrier is its cost.
It will take a long time period (more than 30˜50 years) to resolve three problems mentioned above.
[Stirling Engine]
Stirling engine, invented in 1816 by Robert Stirling who was a Scotland engineer, was once regarded as a promising prime mover in 1980's. In early times of development, the Stirling engine was considered to work at a low temperature difference, which is appropriate for solar applications.
However, at present, the Stirling engine can operate efficiently only for a high-temperature range above 700˜800 degree Celsius. Further, its thermal efficiency is not sufficient.
[FORD Organic Rankine Cycle Turbine]
From 1976 to 1984, a Solar Thermal Power System Project was conducted by the Jet Propulsion Laboratory (JPL). Ford Aerospace and Communications Corporation designed and assembled the organic Rankine cycle turbine, which was the first tentative Rankine cycle and a pioneering work toward an epoch-making prime mover (Leonard D. Jaffe, J. of Solar Energy Engineering, Vol. 110, November 1988, pp. 275-281). As an expander, a radial turbine of single stage impulse type was adopted and toluene was used for the working fluid to cover a high temperature range.
Although the turbine adopted was the conventional radial turbine, they obtained the maximum conversion efficiency of 23 percent and the output power of 21.6 kW with the Carnot efficiency ratio being 44 percent.
This project was indeed very valuable one since it was done as early as 1970's and the validity of organic Rankine cycle was first recognized. If the present invention were incorporated in that project, the vehicle mileage would be at least twice better than the Prius; i.e. 89.4 mpg (or 76 km/l).
[Photovoltaic Cell]
Photovoltaic cell (PV) was first introduced as early as 1950's in US Space program. It has over 50 years history, but the generation efficiency for electricity is still as low as only 10 percent on yearly averaged base. PV is promising technology among solar electricity generation devices. However, there are some barrier in dissemination of PV systems. One is relatively low efficiency and another high cost.
Moreover, the PV can not be used as a bottoming cycle and it needs a battery for energy storage, thereby restricting vulnerability.
[NASA Micro-Gas Turbine]
A micro-gas turbine for use in space was developed by NASA, schematically shown in FIG. 14 . The turbine includes solar receiver, waste heat radiator, regenerator (heat exchanger), compressor, generator, and turbine expander. The output power is 10 kW at 36000 rpm, under inlet temperature of 1144K. According to NASA, its thermal efficiency is reported to be 29%, which indicates that the CER(Carnot efficiency ratio) is only 0.39.
[Previous Off-Centered Design Disk Turbine]
A disk turbine with reverse direction channel flow, which is different from the present invention, is described in Japanese patent application laid-open disclosure number 2004-278335 and 2005-188378. A typical experimental result was designated in FIG. 15 , showing output power versus speed of rotation. It is quite noteworthy that a stall phenomenon clearly appears after taking its maximum power around 3500 rpm. An abrupt decrease of power is seen, thereby causing a dead output at early rotational speed of 5000 rpm as indicated in FIG. 15 . This stall phenomenon is of crucial importance since the thermal efficiency is restricted thereby.
Power due to the viscous force in the above case is proportional to 2.5 power to angular velocity of rotation (ω), so that viscous power loss increases abruptly with rotational speed.
This fatal disadvantage was brought about owing to off-centered design concept itself. Further, there existed a Joule-Thomson effect, which appears in tip clearance region between the housing and the rotor tip.
[Steam Turbine in Power Plants]
FIG. 16 shows the relation between a power rating and a specific steam rate for a steam turbine in power plants, etc., wherein an ordinate indicates the steam rate (kg/h) for generating a power of 1 kW. In this graph, it is seen that the higher the performance of the steam turbine becomes, the lower the steam rate, and this implies the reason why the steam rate in a giant power plant such as a power rate of 1,000,000 kW is low. On the other hand, it is understood in the graph that the efficiency becomes worse in a micro steam turbine of 1 to 100 kW by one tenth.
It is considered that this is resulted from the fact that a flow through (useless flow; not contributing to the power) which flows through tip clearances around a periphery of a rotor, blades, and so on becomes large. In addition, heat transfer and friction loss at wall per unit flow rate are increased to extremely lower an efficiency, together with a surface area per unit flow is large.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an improved down-sized centrifugal reverse flow disk turbine.
Another object of the invention is to provide an improved down-sized centrifugal reverse flow disk turbine having a low steam rate and a high thermal efficiency.
Further object of the invention is to provide an improved down-sized centrifugal reverse flow disk turbine with high cost performance.
The present invention provides a centrifugal reverse flow disk turbine for power generation, comprising; a) a turbine shaft; b) a disk rotor disposed on said turbine shaft; c) a housing, having said turbine shaft and said disk rotor, bearings, seal devices, and at least one jet nozzle means; d) a plurality of radially engraved channel for transporting working fluid from entering ports, placed axially near said turbine shaft; e) plurality of said channels having two curvatures; first curvature has a small radius, and concaved pertinent to rotational direction of said rotor, starting from the entering port to middle of its flow path, and the second curvature has a large radius, convexed pertinent to rotational direction of said rotor, positioned near the peripheral of said rotor; a plurality of a bucket attached at every flow channel, directing against nozzle disposed on said housing, thereby deriving impinging counter supersonic flow.
Also, the present invention provides a method for earning rotational power using said centrifugal reverse flow disk turbine described above, including: a) an impulse force coming from impinging supersonic flows from jets out of nozzles disposed on said housing; b) a reaction force coming from impinging supersonic flows from jets out of nozzles disposed on said housing; c) a force due to counter supersonic flow which arises when two jets, one from fixed nozzle disposed on said housing, and another from rotating blade disk rotor, impinge each other at the prescribed locations; d) a thrust exerted by jet flow from rotating blade disk rotor, which is effective only when the nozzle ejection velocity exceeds the peripheral velocity of rotation; e) a force due to change of momentum at the second curvature of the flow channel; f) a viscous force produced at both walls in a narrow gap between two plain disks, due to radial and the same directional flow as rotation of rotor.
Furthermore, the present invention provides a turbine structure, comprising: a rotor mounted on a shaft, the rotor having a channel for flowing working fluid; a housing for rotationally supporting the shaft to accommodate the rotor in an interior space thereof; and at least one nozzle for ejecting the working fluid to the interior space of the housing at a supersonic velocity, at least one nozzle being provided on an inner wall of the interior space; wherein the rotor is rotated at a first predetermined velocity by receiving the working fluid at a first end portion of the channel, so that the working fluid flows through the channel in the first direction, and the rotor is rotated at a second predetermined velocity higher than the first predetermined velocity by receiving the working fluid from a second end portion of the channel, so that the working fluid flows through the channel in a second direction opposite to the first direction to produce a counter supersonic flow force.
BRIEF DESCRIPTION OF THE DRAWINGS
Next, preferred embodiments according to the invention will be explained in conjunction with appended drawings:
FIG. 1A is a partial cross sectional view for explaining the operation of the centrifugal reverse flow disk turbine.
FIG. 1B is a partial cross sectional view for explaining the operation of the turbine, when the rotational speed is low.
FIG. 1C is a perspective illustration of the turbine.
FIG. 1D is an illustration showing an example of an axi symmetric nozzle arrangement.
FIG. 1E is an illustration showing an example of a two-dimensional nozzle.
FIG. 2A is a vertical sectional view showing the centrifugal reverse flow disk turbine.
FIG. 2B is a parallel sectional view showing the centrifugal reverse flow disk turbine.
FIG. 2C is an exploded perspective illustration showing the centrifugal reverse flow disk turbine.
FIG. 3A is an elevational view of a spacer disk which forms the disk rotor of the first embodiment.
FIG. 3B is an elevational view of a blade disk which forms the disk rotor of the first embodiment.
FIG. 3C is an elevational view of an assembled laminate of the blade disc and the spacer disk.
FIG. 4A is an illustration of Logarithmic spiral.
FIG. 4B is an illustration of Archimedes' spiral.
FIG. 4C is an illustration of Parabolic spiral.
FIG. 4D is an illustration of Hyperbolic spiral.
FIG. 4E is an illustration of Epitrochoid.
FIG. 4F is an illustration of Involute.
FIG. 4G is an illustration of Catenary.
FIG. 4H is an illustration of Involute of Catenary.
FIG. 5A is a cross sectional view of a convergent and divergent nozzle.
FIG. 5B is a cross sectional view of a parallel shaped nozzle.
FIG. 5C is a cross sectional view of a convergent nozzle.
FIG. 6 is a diagram showing the relationship between the Carnot efficiency ratio (CER) and the speed of rotation, for present invention and FreePower radial turbine.
FIG. 7 is a diagram showing the relationship between the pressure and the enthalpy.
FIG. 8 is a conceptual diagram showing a method to obtain a rotational power (cascading stage).
FIG. 9 is a conceptual diagram showing a method to obtain a rotational power (multi-fluid stage).
FIG. 10 is a result of global warming simulations, showing earth's surface temperature rise when CO 2 concentration is doubled.
FIG. 11 is a primary energy production for two scenarios. A solid curve is based on the projection by US Geological Survey, and a dotted curve by Saitoh and Wakashima.
FIG. 12 is a long-term variation of atmospheric CO 2 concentration. After taking peak value in 2100, it will stay almost constant. The most probable curve will be upper curve. Lower curve is obtained from the paper that predicts maximum absorption by ocean and land ecosystems.
FIG. 13 is a Carnot efficiency ratios for various engines. CER of all of existing engines falls under a line of 50% except present SHINLA turbine.
FIG. 14 is a NASA 10 kW micro gas turbine engine for space application.
FIG. 15 is a typical experimental result of a disk turbine with reverse direction channel flow, which is different from the present invention.
FIG. 16 shows the relation between a power rating and a specific steam rate for a steam turbine in power plants, etc.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Best Mode for Carrying Out the Invention
[Operation]
The working principle of the invention will be explained by virtue of FIG. 1A and FIG. 1B , in which only a part of flow channels formed inside the disk rotor is depicted.
In a centrifugal reverse flow disk turbine, when the rotational speed of the rotor is small, the jet ejected from the nozzle 3 disposed on the housing wall flows inwardly along the radial channel 26 after impinging the bucket (cusp) 23 of the rotor. Namely, since the inlet pressure P 1 of the working fluid is higher than the outlet pressure P 2 , a pressure difference ΔP(=P 1 −P 2 ) causes this radially-inward flow (Pressure effect) as shown in FIG. 1B .
Under this range of low speed of rotation, the peripheral rotor velocity u r (=Rω, R: rotor radius, ω: angular velocity of rotation) is much smaller than the ejection velocity u j , and the energy transforming efficiency is reduced to a great extent. On the other hand, if the speed of rotation were increased further, the flow direction in the flow channel 26 may be reversed owing to body force (i.e. centrifugal force), from inward to outward as shown in FIG. 1A . In FIG. 1A , the reference letter “a” shows an inward jet flow ejected from the nozzle 3 , the reference letter “b” shows an outward flow caused by the centrifugal force and the reference letter “c” shows a centrifugal reverse flow in the channel 26 . Thus, there exists a tipping point (or critical point), where the channel flow phenomena is drastically reversed.
The critical rotational speed of the rotor in the present centrifugal reverse flow disk turbine above which the centrifugal effect becomes dominant, is provided by solving the following equation (1);
Tesla
-
Saitoh
number
=
TS
=
Re
Fe
=
R
2
ω
v
Δ
P
μω
>
2
f
1
(
a
,
A
,
R
,
β
,
ϕ
)
where
,
TS
:
Tesla
-
Saitoh
number
=
Re
Fe
Re
:
Reynolds
number
=
R
2
ω
v
Fe
:
Flow
energy
number
=
Δ
P
μω
(
1
)
R: rotor radius
ΔP: pressure difference between at tip clearance and inlet near rotor shaft
ω: angular velocity of rotation
v: kinematic viscosity of working fluid
A, β, φ: parameters determined by given geometry of flow channel
a: starting radius of logarithmic spiral
β
:
S
2
R
(
S
2
:
length
of
flow
channel
)
In the previous equation (1), centrifugal driving is initiated when the Tesla-Saitoh number exceeds a value 2.915 in case that flow channel geometry obeys a logarithmic spiral;
r=a·e p′θ (2)
here,
a: starting radius of logarithmic spiral
θ: angle measured from start line
r: radius
If typical physical properties were given (in this example, one of Hydro Fluoro Carbons: HFC is selected as a working fluid) and R=0.05 m, β=2, φ=60°, A=√(1+p′ 2 )/p′=3.333, and N=40, the critical speed of rotation n can be calculated to be;
n= 10310 rpm
If the speed of rotation exceeds this critical value, the present centrifugal disk turbine will be operated under a centrifugal mode. The optimal speed of rotation is approximately 12000 rpm for previously given conditions.
On the other hand, the optimal speed of rotation for a pressure effect mode is about 6100 rpm, which is much lower than that for a centrifugal mode. In the present centrifugal driving mode, the following six kinds of forces can be utilized to gain rotational power, thereby greatly contributing to a high efficient use of incoming kinetic energy from the nozzle.
(a) P imp : Impulse Force
The force exerted on the disk rotor when the supersonic jet flow from the nozzle 3 impinges bucket 23 and hollow 29 .
(b) P reac : Reaction Force
The force exerted on the disk rotor due to a rebound flow (reaction flow), which is formed after the supersonic jet flow from the nozzle 3 impinges the bottom of the bucket 23 and the hollow 29 .
Thus, two kinds of forces appear when the jet flow impinges the bucket shown in FIG. 1A .
The sum of the two forces is expressed by the following equation;
P imp +P reac =m*u j 2 αr (1− r ) (3)
here,
{dot over (m)}*: mass flow rate of the working fluid
u j : jet velocity from the nozzle
α: coefficient
r: u r /u j =Rω/u j (R: radius, ω: angular velocity)
(c) P csf′ : Counter Supersonic Flow Force
The working fluid entering from an axial mouth 27 is conveyed due to a centrifugal force to the bucket 23 at peripheral of the rotor, and ejected in the opposite direction to the rotation of the rotor. This outward flow brings a counter supersonic flow with the jet from the nozzle fixed to the housing. As a result, P csf has a similar effect as an impulse force, thereby increasing the rotational power. The counter supersonic flow effect is evaluated by the following equation;
P csf ={dot over (m)}*u j 2 αr·r csf (4)
here,
r csf : velocity ratio due to counter supersonic flows
(d) P th : Thrust
The working fluid entrained from the axial mouth 27 is transported due to a centrifugal effect to the bucket 23 at peripheral of the rotor, and ejected into tip clearance space. If this injection velocity is larger than the rotor tip speed u R (=Rω), the thrust is produced, which is expressed by the following equation;
P th ={dot over (m)}*u R ( v r −u R ) (5)
here,
v r : ejection velocity from the bucket 23
u R : rotor tip speed
(e) P vis : Viscous Force
The torque force in the rotational direction exerted by a viscous (friction) effect which is generated when the working fluid entrained from the axial mouth 27 passes through a narrow-spaced flow channel 26 . This force is available when the first curvature 30 has a concaved geometric configuration opposite to the direction of rotation. The viscous force P vis is designated by the following equation;
P
vis
=
π
4
G
′
(
0
)
N
μω
2
R
3
Re
(
6
)
here,
Re: Reynolds number
R: radius of the rotor
ω: angular velocity of rotation
μ: viscosity
N: number of blade disk
The above equation gives an important relationship to clarify the mechanism of the invention. In equation (6), G′(0) means the velocity gradient at the wall of the flow channel, and its value is obtained by solving the relevant partial differential equations to be G′(0)=0.6160.
(f) P mc : Momentum Change Force
This force is generated at the second curvature 31 of the flow channel 26 when the direction of the flow turns abruptly, thereby changing its momentum M(=mv, m: mass, v: velocity). The force due to momentum change is given by the following equation;
P
mc
=
R
ω
ⅆ
M
ⅆ
t
(
7
)
here,
M: momentum
t: time
ω: angular velocity of rotation
In conventional large-scale steam power plants of 1 GW (gigawatt) class, including fossil and nuclear powered, obtainable forces are only two kinds; (a) impulse force, and (b) reaction force, which are available under a supersonic flow from the nozzle. On the other hand, in the present invention, six kinds of forces and effects can be exploited as mentioned before. Further, whereas the conventional large-scale steam turbines use the water vapor (H 2 O) as a working fluid, the invention uses a working fluid with very low kinematic viscosity (about two order of magnitude smaller than the water vapor).
This is of crucial importance in the present invention since the boundary layer near the spacer disk gets very thin, thereby making radially-outward viscous flow eminent even if the disk spacing is very narrow (for example, 100 micron meters). This also contributes to a highest possible power density and a lowest cost of the invention compared with the conventional prime movers. As a result, Carnot efficiency ratio (CER) of the invention reaches about 90%.
Best Mode for Carrying out the Invention
In the first embodiment of the present invention as illustrated in FIG. 2A , FIG. 2B and FIG. 2C , the centrifugal reverse flow disk turbine 10 includes a turbine shaft 5 , a disk rotor 1 fixed on said turbine shaft 5 , and a housing or casing 2 which installs said disk rotor 1 and a plurality of supersonic nozzle 3 . Said rotor 1 is placed with rotational-free onto said turbine shaft 5 .
Said rotor 1 and said housing 2 is spaced with a prescribed spacing so that the windage loss due to rotation of the rotor 1 could be reduced, preferably spacing is chosen to be 1˜3 percent of the rotor radius. In the vicinity of the turbine shaft 5 of said housing 2 , there are exhaust port 4 . Aforesaid nozzle 3 is preferably the convergent and divergent nozzle (i.e. de Laval nozzle).
In this embodiment, the nozzle 3 is an axi symmetric nozzle which has a convergent portion 3 a , a throat portion 3 c and a divergent portion 3 b as shown in FIG. 1D . The nozzles 3 may include various geometries and are not limited to the specific shape being shown and may have different shapes. FIG. 1C shows axially-aligned three nozzles 3 of the housing 2 . In the case of a larger power (for example, more than 5 kW), a plurality of axially-aligned nozzles 3 or a two-dimensional nozzle 3 is preferably used in the rotor 10 . FIG. 1E shows an example of a two-dimensional nozzle.
It should be appreciated that any number of nozzles 3 can be used with the present disclosure, and this number can vary depending on the output power. In this embodiment, there are two nozzles 3 in a circumferential direction as shown in FIG. 2A . Preferably a number of nozzles 3 in the circumferential direction are 4-8, the more the better.
The disk rotor 1 , as designated in FIG. 1A , has the flow suction mouth 27 , which penetrates in the axial direction and connects with two spaces between the housing 2 and the disk rotor 1 . The disk rotor 1 also has a plurality of radial flow channels 26 and these disks and the neighboring spacer disks are laminated together in the axial direction. Aforementioned axial suction mouth 27 can take an arbitrary shape, but it is desirable that the total aperture area should be by far larger than the total inlet area of the radial flow channels.
The disk rotor 1 is comprised of a rib-shaped blade disk with flow channels having two curvatures, radially directed, and axial suction mouths placed near said rotor shaft and two plain spacer disks having buckets (cusps) at peripheral and axial mouths placed near said rotor shaft, and further, a plurality of lamination of disks of above a) and b) in the axial direction. The previous bucket 23 of the radial flow channel 26 , preferably, has a nozzle. It is also desirable that small bucket 22 are formed in order to get impulse and reaction forces from supersonic flows out of nozzles attached onto the housing.
In this embodiment, there are forty pairs of blade and spacer disks which forms a rotor 1 in the turbine 10 and there are ten buckets 23 formed on each of the rotors 1 . It should be appreciated that any number of rotors 1 and buckets 23 can be used with the present disclosure, and these number can vary depending on the output power. Preferably a number of buckets 23 formed on the rotor 1 are 60-80, the more the better. Also, a number of pairs of blade and spacer disks, which consists rotor 1 in the turbine 10 can be 100-200.
The First Embodiment of the Present Invention
Said disk rotor 1 in the first embodiment is comprised of a spacer disk 20 shown in FIG. 3A , and a rib-shaped blade disk with flow channels, shown in FIG. 3B , and two kinds of disks are laminated by turns in the axial direction to make a disk rotor. The spacer disk has buckets (cusps) at peripheral and axial mouths placed near said rotor shaft. The blade disk has a plurality of rib-shaped blades 25 and small buckets 22 with the same shape as the one in spacer disk 20 .
As shown in FIG. 3C , by laminating the blade disk and the spacer disk together in the axial direction, the radial flow channel 26 is formed in between two disks. This flow channel has two curvatures; one is located on the way to the second curvature and has a large radius of curvature with a concaved shape to rotational direction, another is located near the tip and having a small radius curvature with a convexed shape to rotational direction.
Axial suction mouths are placed near said rotor shaft for entraining working fluid, and both spacer and blade disks have buckets (cusps) at peripheral so that supersonic jet from the nozzle impinges. There are screw holes 32 to fasten the lamination of the spacer and blade disks. Serrated buckets for receiving supersonic jets from the nozzle 3 are composed by lamination of these disks, as a consequence.
The number N of blade and spacer disks can be determined by using equation (6), for example, so that the friction and entropy losses do not exceed an appropriate value. The extractable power from the invention is strongly dependent upon the rotor diameter, the number of blade and spacer disks, and given flow conditions, including flow rate, pressure, temperature, physical properties of the working fluid used, and the geometry of the housing such as spacing between the disk rotor and the housing, and tip clearance between the rotor tip and the ceiling of the housing.
Geometric configuration of the first curvature of said flow channel of the blade disk is desirable to be the following curves (see FIG. 4A to FIG. 4H );
(a) Logarithmic Spiral;
r=ae p′θ ( a> 0) (8)
(b) Archimedes' Spiral;
r=aθ ( a> 0) (9)
(c) Parabolic Spiral;
r 2 =aθ ( a> 0) (10)
(d) Hyperbolic Spiral;
rθ=a ( a> 0) (11)
(e) Epitrochoid;
r= 2 a (1+cos θ)( a> 0) (12)
(f) Involute;
x =(cos φ)+φ sin φ
y=a (sin φ−φ cos φ (13)
(g) Catenary;
y = a cosh x a = a 2 ( ⅇ x a + ⅇ - x a ) ( a > 0 ) ( 14 )
(h) Involute of Catenary;
x
=
a
arccos
a
y
±
a
2
-
y
2
(
a
>
0
)
(
15
)
Another curve is conceivable smooth and gentle shaped similar one derived from the above mathematical curves. In an example illustrated in FIG. 3C , a logarithmic spiral, with the same flow direction as that of rotation of said rotor, thereby utilizing a friction force (viscous force) formed between a narrow spacing of said blade disk.
The second curvature of the previous flow channel 26 , placed in the vicinity of the blade disk tip, is desirable to take a crooked bend in order to yield a momentum change (for example, in FIG. 3C , angle change is about 90 degrees). The number of the blade 25 in FIG. 3C is ten, however, if there is no manufacturing limitation, it is desirable to take as many as possible. There are optimal values for said radii of the spacer disk and the blade disk, numbers thereof, speed of rotation, depending upon given working fluid and various flow conditions at the inlet of the rotor housing. The optimal design can be done using equations prescribed before (see eqs. (1)˜(7)).
[Micro-Nozzle Configurations]
As for configuration of micro-nozzle set at the exit of blade disk, the preferable one is a convergent and divergent nozzle (i.e. de Laval nozzle) as in FIG. 5A , but a convergent nozzle or a parallel shaped nozzle will be selected in some cases (in FIG. 5B and FIG. 5C ). Of these, the de Laval type nozzle can be utilized only for gaseous fluids.
In particular, in case of the working fluid having a very low kinematic viscosity, such as Chloro Fluoro Carbons (CFCs), Hydro Fluoro Carbons (HFCs), Hydrogenerated Chloro Fluoro Carbons (HCFCs), Hydro Carbons (HCs), and Alcohols, etc., an appropriate thickness of the blade disk (spacing of the flow channel) takes an optimal value of order of micron-, submicron-, and nano-meter.
The material for said spacer and blade disks is preferably made of metal; such as stainless steel, aluminum, titan, and other corrosion-resistant metal alloys. However, in some cases, plastics, fiber reinforced plastic (FRP), ceramics, and heat-resistant glasses. The previous mentioned spacer and blade disks can be manufactured by using a laser processing, discharging processing of electricity, and punching processing, as well.
[Experiment]
In one experiment of the present invention, a typical experiment was performed using one of HFCs as the working fluid for a prescribed condition appropriate for solar applications. The number of blade/spacer disk set is 40, the number of blade (flow channel) for one blade disk 10 , diameter 0.1 m, the flow rate 0.0262 kg/s, inlet pressure of nozzle 1.5 MPa, inlet temperature 126 degrees Celsius, and the rotational speed 11800 rpm. In this experiment, twin nozzles are utilized, being secured to the housing with 180° apart.
The results of experimental performance is plotted in FIG. 6 . The ordinate shows the Carnot efficiency ratio (CER), previously defined, and the abscissa shows the speed of rotation. A peak power is obtained around n=10000˜12000 rpm, and it is noteworthy that the CER value of the present invention reaches about 90%.
Also plotted in the figure is an estimated performance curve of conventional radial Rankine cycle turbine (3-stage) manufactured by FreePower Company (UK). By comparison of two results, it is clearly known that the CER value of the present invention is by far superior to the conventional one, thereby validating the present invention.
Referring now to FIG. 7 , there is shown a pressure-enthalpy diagram of the present invention, undergoing organic Rankine cycle. By a circulating pump, the fluid (liquid) at state 1 ′ is pumped to the state 2 ′, then the fluid is evaporated from the state 2 ′ to the state 3 ′, where the maximum enthalpy state is achieved. High pressure and temperature gas is introduced to the nozzles, disposed to the housing, thereby ejecting supersonic flows against the rotor to yield a rotational power.
The exhaust gas is recirculated after reaching the state 4 ′ and entrained through the mouth disposed near the shaft. By a centrifugal force, the entrained fluid is conveyed raidially-outward toward the exit (micro-nozzle), at the same time, the working fluid is heated by the entropy increase due to friction on the walls of the narrow channel, thereby causing an increase of entropy and temperature, as a path from the state 4 ′ to the state 5 ′ shown in FIG. 7 . Then, the Rankine cycle is closed by taking a path from the state 5 ′ to the state 1 ′(original state).
It is especially noted that the recirculating centrifugal flow plays an important role to produce supersonic flows from the micro-nozzles attached to the rotor at the sacrifice of the entropy loss during the state 4 ′ and the state 5 ′, thereby making 400 supersonic flows (in this experiment). This is the most important feature in the present invention.
The Second Embodiment of the Present Invention
The second mode for carrying out the invention is a united or integrated structure including said two spacer disks and one blade disk. This structure is quite different from that of the first mode for carrying out the invention, in which a plurality of spacer and blade disks are alternatively laminated. An entire rotor is combinedly formed by piling up in the axial direction.
The said disk rotor 1 also has a plurality of radial flow channels 26 and the united blade and spacer disks are laminated in the axial direction. Aforementioned axial suction mouth can take an arbitrary shape, but it is desirable that the total aperture area should be by far larger than the total inlet area of the radial flow channels.
Said disk rotor 1 is comprised of lamination of a united hub-and-spoke shaped blade and spacer disk with flow channels having two curvatures, radially directed, and axial suction mouths placed near said rotor shaft and united blade and spacer disks having buckets (cusps) at peripheral and axial mouths placed near said rotor shaft. The previous bucket 23 of the radial flow channel 26 , preferably, has a nozzle. It is also desirable that small bucket 22 are formed in order to get impulse and reaction forces from supersonic flows out of nozzles attached onto the housing.
The number N of blade and spacer disks can be determined by using equation (6), for example, so that the friction and entropy losses do not exceed an appropriate value. The extractable power from the invention is strongly dependent upon the rotor diameter, the number of blade and spacer disks, and given flow conditions, including flow rate, pressure, temperature, physical properties of the working fluid used, and the geometry of the housing such as spacing between the disk rotor and the housing, and tip clearance between the rotor tip and the ceiling of the housing. There are optimal values for said radii of the spacer disk and the blade disk, numbers thereof, speed of rotation, depending upon given working fluid and various flow conditions at the inlet of the rotor housing. The optimal design can be done using equations prescribed before (see eq. (1)˜(7)).
In particular, in case of the working fluid having a very low kinematic viscosity, such as Chloro Fluoro Carbons (CFCs), Hydro Fluoro Carbons (HFCs), Hydrogenerated Chloro Fluoro Carbons (HCFCs), Hydro Carbons (HCs), and Alcohols, etc., an appropriate thickness of the blade disk (spacing of the flow channel) takes an optimal value of order of micron-, submicron-, and nano-meter.
The material for said spacer and blade disks is preferably made of metal; such as stainless steel, aluminum, titan, and other collosion-resistant metal alloys. However, in some cases, plastics, fiber reinforced plastics (FRP), ceramics, and heat-resistant glasses. The previous mentioned spacer and blade disks can be manufactured by using a laser processing, discharging processing of electricity, and punching processing, as well.
[Method to Obtain a Rotational Power]
An impulse force is obtained when the supersonic jet from the nozzle 3 placed on the housing 2 , impinges a bucket 22 formed at peripheral of the previous rotor 1 , and simultaneously, the supersonic jet reached the bottom 29 of said bucket rebounds in the direction opposite to rotor rotation, thereby making a reaction force.
On the other hand, in case that the rotational speed of the rotor 1 exceeds a threshold value (a tipping point) designated by the previous equation (1), the working fluid flow through channel 26 changes its direction to a radially outward flow, owing to a centrifugal effect exerted by a high rotational speed. As a consequence, this centrifugal flow ejects from the nozzle 28 disposed on the peripheral of the rotor 1 , thereby producing a thrust (propulsion force).
Further, a counter flow occurs when this supersonic jet from the nozzle 28 impinges the supersonic jet from the nozzle 3 . The resultant counter supersonic flow (CSF) greatly enhances the impulse force. In addition, a rotationally-positive torque is generated due to a viscous effect when the working fluid passes first curvature of flow channel 26 . Lastly, the force due to momentum change is yielded when the working fluid passes the second curvature 31 , thereby contributing a positive rotational power.
A special notice should be said on the working fluid, since a working fluid with an extremely low kinematic viscosity is strongly recommended for the present invention; for instance, Chloro Fluoro Carbons (CFCs), Hydro Fluoro Carbons (HFCs), Hydrogenerated Chloro Fluoro Carbons (HCFCs), Hydro Carbons (HCs), and Alcohols, and their alternatives.
Most preferable range of kinematic viscosity will be less than about 2×10 −7 m 2 /s. For example, whereas the kinematic viscosity of water vapor and carbon dioxide (CO 2 ) take 1.2×10 −5 and 1.45×10 −5 m 2 /s, respectively, at the same temperature of 120 degree Celsius, one of Hydro Fluoro Carbons (HFCs) takes a value 1.3×10 −7 m 2 /s, this being about two order of magnitude lower than that of water vapor and carbon dioxide.
Selecting a working fluid with a very low kinematic viscosity is of crucial importance, unless otherwise the size of the prime mover becomes large to a great extent. A high-efficient and compact turbine could not be expected at all if the working fluid with high kinematic viscosity were chosen, since enough viscous force, counter supersonic flow, thrust, and increased impulse force are not available. This gives a solution to the reason why the conventional steam turbine of moderate size were inefficient.
Above mentioned points are a key factor in the present invention. Energy possessed by the working fluid 50 is further extracted efficiently by placing a plurality of the previous centrifugal reverse flow disk turbine 10 on the same shaft, as shown in FIG. 8 . The working fluid passes these turbine units in a cascading manner. Power can be generated by the generator 55 connected co-axially with the rotor shaft. Electric power thus generated is utilized to drive either electric or hybrid vehicle. The shaft power can be also directly connected with compressor to operate air conditioners. Although, in FIG. 8 , only a 3-stage disk turbine is designated, however, the stage number can be chosen arbitrarily.
It is also possible to extract a rotational power from the multi-stage centrifugal reverse flow turbine as indicated in FIG. 9 . In this case, the different working fluids 50 , 51 , 52 passes the respective unit under the different cycle (multi-fluid cycle). In FIG. 9 , only a 3-stage disk turbine is illustrated, however, the stage number can be selected arbitrarily. Moreover, the kind of the working fluid is also taken arbitrarily.
The present invention can be used in various applications such as (1) solar applications, (2) automobiles, aircraft, ship, and railroad applications, (3) space applications, (4) sea water desalination, (5) fuel production, for example hydrogen, ethanol, methanol and biogases, (6) industrial/public welfare applications, (7) steam production, (8) separation/recovery, underground storage, sequestration in deep sea of carbon dioxide, (9) ocean thermal energy conversion and (10) food production and breeding. The total world marketing value will be 59.5 Trillion$.
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A centrifugal reverse flow disk turbine for power generation, comprising; a) a turbine shaft; b) a disk rotor disposed on said turbine shaft; c) a housing, having said turbine shaft and said disk rotor, bearings, seal devices, and at least one jet nozzle means; d) a plurality of radially engraved channel for transporting working fluid from entering ports, placed axially near said turbine shaft; e) a plurality of said channels having two curvatures; first curvature has a small radius, and concaved pertinent to rotational direction of said rotor, starting from the entering port to middle of its flow path, and the second curvature has a large radius, convexed pertinent to rotational direction of said rotor, positioned near the peripheral of said rotor; a plurality of a bucket attached at every flow channel, directing against nozzle disposed on said housing, thereby deriving impinging counter supersonic flow.
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CROSS REFERENCE TO RELATED APPLICATION
This application claims priority from German Patent Application Nos. 103 389 47.4 dated 25 Aug. 2003 and 10 2004 033 509.5 dated 10 Jul. 2004, the disclosures of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
The invention relates to a card top assembly for a carding machine.
In a known kind of carding machine cotton, synthetic fibres and the like, there is at least one card top bar having card top clothing, the card top clothing being fastened to the card top bar and positioned opposite to the clothing of a roller, e.g. the cylinder, and at least the regions of the clothing that face the card top bar being made of a ferrous product, especially steel.
In a known arrangement (U.S. Pat. No. 3,151,362), the card top bar consists of a back portion and a carrier body (carrier) having a foot face. Fastened to the foot face (portion that accommodates the clothing) is all-steel clothing or a clothing strip (flexible clothing) that extends in the longitudinal direction of the foot face. The all-steel clothing consists of a large number of saw-tooth wire portions arranged adjacent to one another. The clothing strip comprises a carrying element consisting of a plurality of textile layers, in which a large number of small wire hooks (clothing tips) are fastened. The regions of the steel clothings that are in each case remote from the tips are associated with the card top bar. The clothing strip is fastened along the longitudinal sides of the carrier body by means of two clamps (brackets, clips). With one end, the clamps encompass the longitudinally oriented edge regions of the clothing strip and with their other end engage in recesses in the carrier body. In practice, the clamps consist of a sheet metal strip, one longitudinal edge of which is cut into the textile material. On assembly, the textile material of the clothing strip is fastened to the carrier body of the card top bar in a positive fit under considerable stress. In the process, the clamps exert tensile forces in such a manner that the textile material is deformed convexly away from the foot face, so that the clothing tips facing outwards are also, undesirably, arranged on a convex-shaped envelope. When not in use, the resulting card top assembly has a precision of 0.05 mm in height and evenness. In use, the differences in height in the assembly increase to approximately 0.2 mm. Sharpening the clothing on the machine improves precision only insignificantly. After a throughput of approximately 400 t of fibre material, the card top clothing is so worn that it has to be replaced. In order to dismantle the sheet metal staples, the card top bar is clamped and the positive fit is reversed by means of a lever and pincers. The considerable forces that occur during assembly and dismantling have a deleterious effect on the dimensional stability of the card top bar.
It is an aim of the invention to provide an arrangement of the type described at the beginning that avoids or mitigates the disadvantages mentioned, makes it possible, especially in simple manner, to obtain a clothed card top bar that is dimensionally stable and enables simpler and more rapid reclothing (clothing replacement).
SUMMARY OF THE INVENTION
The invention provides a card top bar for a carding machine, comprising a card top bar carrier member; a clothing member comprising a ferrous portion; and at least one magnetic element positioned between the card top bar carrier member and said ferrous portion of said clothing member.
The solution makes it possible to obtain a simplified seating for the clothing strip (carrier layer and wires arranged in accordance with the setting configuration) on the card top bar, which additionally enables replacement to be made without causing any damage. For example, when the clothing is worn, the clothing strip to be replaced can be removed easily and the undamaged card top bar having the clothing seating according to the invention can be used for a new clothing strip.
Advantageously, a magnetic component comprising a said magnet is fastened to the card top bar carrier member. Advantageously, a magnetic component comprising a said magnetic element is fastened by means of an adhesive layer or the like. Advantageously, a magnetic component comprising a said magnetic element is fastened by a screw connection or the like. Advantageously, the or each magnetic element is a permanent magnet, for example is of a permanent magnetic material. Advantageously, the magnetic force is greater than the forces acting upon the clothing member, e.g. carding force, force of a rotating cleaning roller or the like. Advantageously, the clothing member is detachable from the magnetic component. Advantageously, the clothing member is connected to the card top bar by means of the magnetic component as fastening element.
Advantageously, the clothing is reversibly detachable from the magnetic component. Advantageously, the clothing, which is set into a backing layer, e.g. fabric or the like, consists of wires or the like that are bent approximately in a U-shape and are so inset that the web portion of the U-shaped wires or the like runs on the reverse side of the backing layer. Advantageously, a compensating layer is present between the card top bar carrier member and the clothing member, which compensating layer is able to compensate for different spacings between the carrier member and the clothing member. Advantageously, the compensating layer is able to compensate for different spacings between the reverse face of the card top clothing member and the foot face of the card top bar carrier member. A compensating layer may be able to compensate for one or more of: different spacings between the sliding surfaces of the card top heads and the foot face of the card top bar; different spacings between the sliding surfaces of the card top heads and the circle formed by the tips of the clothing; different spacings between the circle formed by the tips of the clothing and the circle formed by the tips of the clothing on the cylinder; local different spacings between the reverse face and the foot face. The upper face of the cylinder clothing may constitute a reference surface for the orientation of the card top bar carrier member and of the card top clothing member. The card top bar may form part of a revolving card top. The card top bar may be a fixed carding element.
Advantageously, flexible clothing is present. Advantageously, the flexible clothing comprises a carrier and clothing tips, wires, hooks or the like. Advantageously the carrier is strip-shaped. Advantageously, the clothing consists of saw-tooth wire strips, e.g. all-steel clothing. Advantageously, the clothing is mounted on the card top bar carrier member in the region of the foot face. Advantageously, a plastics material, an artificial resin, e.g. epoxy resin, or the like is provided as compensating substance. The card top bar carrier member may be a shape extruded from a light metal, e.g. aluminium. The extruded shape may be a hollow shape. Advantageously, two end pieces (card top heads) are associated with the carrier body. Preferably, the end pieces are pins of hardened steel or the like. Advantageously, the carrier element (textile material) and the compensating layer are arranged in a recess of the foot face (carrier body). Preferably, the recess is limited by at least two lateral webs or the like on the longitudinal sides of the carrier body.
Advantageously, the underside of the clothing strip, on which the spines of the bent wires are located, is held securely by means of a magnet fixed to the card top bar carrier member. Advantageously, the clothing strip is additionally fixed laterally to the side faces of the carrier layer, for example by webs mounted on the card top bar carrier member. Advantageously, all the clothing strips, e.g. irrespective of the setting configuration, are arranged to be held flexibly by a magnet, so providing the connection to the card top bar carrier member.
Advantageously, the connection is supported mechanically, e.g. by pieces of sheet metal fastened to the card top bar carrier member. Advantageously, there is additional securing or holding of the clothing strip in the horizontal plane e.g. by the clothing strips being held mechanically by webs. Advantageously, two webs are present on the longitudinal sides and/or two webs are present on the transverse sides. Advantageously, a clothing strip is accommodated, to which there is additionally fastened, by way of a compensating adhesive layer, a piece of sheet metal which is brought into contact with the magnet of the card top bar carrier member. Advantageously, the vertical connection is supported mechanically. Advantageously, the clothing strip is additionally provided with e.g. wire claws or the like at its outer edges where there is only carrier layer and none of the wires embedded therein.
Advantageously, the magnetic component, e.g. magnetic tape, magnetic strip, magnetic bar or the like, extends in the longitudinal direction of the card top bar. Advantageously, a plurality of magnetic elements is present in the longitudinal direction of the card top bar. Advantageously, the magnetic elements are arranged spaced from one another. Advantageously, the magnetic elements are arranged offset relative to one another. Advantageously, the direction of offsetting is the working direction. Advantageously, a base made from a magnetic material is arranged on the reverse side of the card top clothing member. Preferably, the base is a steel tape, piece of sheet metal or the like.
Preferably, the base has on its sides attachments, webs or the like that are bent at an angle. Advantageously, the card top clothing member has at least two groups of clothing, each of which is held by a magnet. Advantageously, at least two groups of clothing each have a heel zone relative to the roller clothing. Advantageously, the card top clothing member consists of a large number of all-steel clothing wires arranged axially relative to the clothed roller, e.g. cylinder. Advantageously, the card top clothing member is held on the card top bar carrier member by at least one magnetic element. Advantageously, the card top bar carrier member consists of a fibre-reinforced plastics material, for example, a glass-fibre-reinforced plastics material is used. Advantageously, a carbon-fibre-reinforced plastics material is used. Advantageously, the magnetic element is integrated in the fibre-reinforced plastics material, for example, by casting the magnetic element integrally with the plastics card top bar carrier member. The magnetic element may be cast or pressed into the plastics card top bar carrier member. Advantageously, the magnetic element is incorporated during manufacture of the plastics card top bar carrier member. Advantageously, at least one and preferably each of the edge regions bordering the longitudinal edges is provided with tips.
The invention also provides a card top bar for a carding machine, having a card top bar carrier member and a clothing member attached to the card top carrier member with an inner surface of the clothing member facing the carrier member, at least a region of the inner surface comprising a ferrous material, wherein at least one magnetic element is provided between the carrier member and the ferrous region or regions of the clothing member.
Moreover, the invention provides an arrangement at a carding machine for cotton, synthetic fibres and the like, in which there is at least one card top bar having card top clothing, the card top clothing being fastened to the card top bar and positioned opposite to the clothing of a roller, e.g. the cylinder, and at least the regions of the card top clothing that face the card top bar being made of a ferrous product, especially steel, wherein between the card top bar and the regions of the card top clothing facing the card top bar there is at least one magnetic element.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic side view of a carding machine comprising an arrangement according to the invention;
FIG. 2 shows card top bars with a cut-away view of a slideway and a flexible bend;
FIG. 3 is a perspective view of a clothing strip comprising a carrier layer and small wire hooks;
FIG. 4 is a side view of a card top bar, in detail, comprising magnetic strip and all-steel clothing;
FIG. 5 a is a side view of a card top bar, as in FIG. 4 but with the magnetic strip and clothing strip (small wire hook clothing), in the assembled state;
FIG. 5 b is a side view of a card top bar, as in FIG. 5 a , but with the clothing strip detached;
FIG. 5 c is a cut-away view of a card top foot having two recesses;
FIG. 6 is a side view of a card top bar having additional fastening elements for the card top clothing;
FIG. 7 is a side view of a card top bar having an additional sheet metal base, for example a steel strip and a compensating layer on the reverse side of the card top clothing;
FIG. 8 is a plan view of an integral magnetic strip;
FIG. 9 is a plan view of a magnetic element consisting of a plurality of individual magnets;
FIG. 10 is a side view of a card top bar having two groups of clothing, each having a heel zone and having two magnets;
FIG. 11 is a perspective view of a card top bar comprising a large number of all-steel clothing wires arranged parallel to the axis of the clothed roller;
FIG. 12 a is a side view of a card top bar made from fibre-reinforced plastics having an integrated magnetic element; and
FIG. 12 b shows a portion of the card top bar according to FIG. 12 a with card top clothing fastened to the magnet.
DESCRIPTION OF PREFERRED EMBODIMENTS
With reference to FIG. 1 . a carding machine, for example a TC 03 carding machine made by Trützschler GmbH & Co. KG of Mönchengladbach, Germany, comprises a feed roller 1 , feed table 2 , lickers-in 3 a , 3 b , 3 c , cylinder 4 , doffer 5 , stripper roller 6 , nip rollers 7 , 8 , web-guiding element 9 , web funnel 10 , draw-off rollers 11 , 12 , revolving card top 13 having card-top-deflecting rollers 13 a , 13 b and card top bars 14 , can 15 and can coiler 16 . The directions of rotation of the rollers are indicated by curved arrows. Reference letter M denotes the centre (axis) of the cylinder 4 . Reference numeral 4 a denotes the clothing and reference numeral 4 b denotes the direction of rotation of the cylinder 4 . Reference letter C denotes the direction of rotation of the revolving card top 13 at the carding location and reference letter D denotes the direction in which the card top bars 14 are moved on the reverse side.
Referring to FIG. 2 , a flexible bend 17 comprising a plurality of adjusting screws is fastened laterally by screws to each side of the machine framework. The flexible bend 17 has a convex outer face 17 a and a lower face 17 b . Above the flexible bend 17 there is a slideway 20 , for example made of a slideable plastics material, that has a convex outer face 20 a and a concave inner face 20 b . The concave inner face 20 b rests on the convex outer face 17 a . The card top bars 14 , which are extruded from aluminium, have a carrier body 14 c and, at both their ends, have a card top foot 14 a to which there are fastened axially two steel pins 18 which slide on the convex outer face 20 a of the slideway 20 in the direction of arrow C. The card top clothing 24 is attached to the lower face of the card top foot 14 a . Reference numeral 23 denotes the circle formed by the tips of the card top clothings 24 .
The cylinder 4 has around its circumference a cylinder clothing 4 a , for example saw-tooth clothing. Reference numeral 22 denotes the circle formed by the tips of the cylinder clothing 4 a . The distance between the tip circle 23 and the tip circle 22 is denoted by reference letter a and is, for example, 2/1000″. The distance between the convex outer face 20 a and the tip circle 22 is denoted by reference letter b. The variable radius of the convex outer face 20 a is denoted by reference letter r 1 and the constant radius of the tip circle 22 is denoted by reference letter r 2 . The radius r 2 intersects the centre M (see FIG. 1 ) of the cylinder 4 . Reference numeral 14 c denotes the backs of the card top bars. Reference numeral 19 denotes a clamping element that engages the card top pins 18 and that is connected to the drive belt (not shown) for the card top bars 14 .
In the embodiment of FIG. 3 , the card top clothing 24 consists of clothing tips 26 (small wire hooks) and a carrier element 25 of a textile material. The small wire hooks 26 are approximately U-shaped and are fastened in the carrier element 25 by being pushed through the surface 25 ′. The bent-round regions 26 ′ of the small wire hooks 26 project above the surface 25 ′. The ends of the wire hooks 26 , that is to say the clothing tips, are free. The wire hooks 26 are made of steel wire.
In the embodiment of FIG. 4 , two webs 14 d , 14 e are arranged on the card top foot 14 a laterally in the longitudinal direction, so that in the region of the foot face 14 b (see FIG. 5 c ) there is a two-step recess 14 f 1 , 14 f 2 (see FIG. 5 b , 5 c ). As a result, the card top clothing 24 2 is held, protected and embedded. In the upper recess 14 f 1 there is arranged a magnetic element 29 , for example a magnetic tape, magnetic strip, magnetic bar or the like, which is fastened to the foot face 14 b 1 by an adhesive layer 30 . In the lower recess 14 f 2 there is arranged the card top clothing 24 2 , which consists of a large number of saw-tooth all-steel clothing strips 28 that are held in position by a steel cassette 27 . The card top clothing 24 2 is fastened to or held in position on the magnetic element 29 by its region remote from the free clothing tips (teeth).
In the embodiment shown in FIGS. 5 a and 5 b , the card top clothing 24 , consists of small wire hooks 26 and a carrier element 25 (see FIG. 3 ). FIG. 5 a shows the card top bar 14 and the card top clothing 24 , in the assembled state, the card top clothing or its bent-round regions 26 ′ being held securely by the magnet 29 so that forces acting on the card top clothing 24 , by the carding machine in operation are not able to detach the card top clothing 24 , from the magnet 29 . According to FIG. 5 b , the card top clothing 24 , has been separated from the magnet 29 and removed from the recess 14 f 21 for example in the event of wear, damage or the like of the clothing hooks 26 . Separation from the magnet 29 can be effected by a suitable tool by means of which the holding magnetic force can be overcome. The separation can also be effected while the carding machine is running in operation during the return of the card top bars 14 on the reverse side (see arrow D in FIG. 1 ).
FIG. 5 c shows a portion of the two-step recess, recess 14 f 1 having a foot face 14 b 1 and recess 14 f 2 having a foot face 14 b 2 . As can be seen in FIGS. 4 , 5 a and 5 b , 6 and 7 , the width c of recess 14 f 1 is smaller than the width d of recess 14 f 2 .
In the embodiment of FIG. 6 , two pieces of sheet metal 31 a and 31 b , for example made from aluminium, are mounted on the longitudinal outer sides of the webs 14 d and 14 e , the free end regions of which pieces of sheet metal are bent at right angles in opposite directions ( 31 a ′ counter-clockwise and 31 b ′ clockwise) around the lower region of the webs 14 d , 14 e . In the position shown in FIG. 6 , the regions that have been bent round 31 a ′, 31 b ′ provide additional holding of the carrier element 25 of the card top clothing 24 1 . Before detachment of the card top clothing 24 1 from the magnet 29 , the end regions are bent open through 90° ( 31 a ′ clockwise and 31 b ′ counter-clockwise). The sheet metal pieces 31 a , 31 b can also be formed resiliently in the form of clips.
FIG. 7 shows an embodiment of a simplified seating for clothing (magnet 29 ) that additionally comprises a compensating layer 32 , by means of which it is possible to obtain greater card top precision and a larger fastening surface area. The compensating layer 32 is advantageously an adhesive layer, to which a piece of sheet metal 33 or the like, for example a piece of sheet steel, is fastened, which is in contact with the magnet 29 . The magnet 29 is fastened to the card top foot 14 a by lateral screws 34 a , 34 b.
FIG. 8 shows an elongate strip-shaped magnet 29 . According to FIG. 9 , the magnetic element consists of a plurality or large number of magnets 29 a to 29 n.
In the embodiment of FIG. 10 , the tips of the clothing 26 are divided into two groups 26 1 , 26 2 with two carrier elements 25 , and 252 , respectively. The two card top clothing strips so formed are each fastened to an associated magnetic element 291 and 292 , respectively, for example, by respective adhesive strips 30 1 and 30 2 . The tips of the groups 261 , 262 are arranged at a tangent to the clothing 4 a of the cylinder 4 at angles α and β, respectively. In that manner each group has a heel zone (narrowest point between the card top clothing and the cylinder clothing). The card top clothing may have a ground heel portion known per se (not shown) at the narrowest point. The heel zone and ground heel portion may similarly be present in the other embodiments of the invention.
In the embodiment of FIG. 11 , a large number of all-steel clothing wires 35 are arranged parallel to the axial direction, for example, of the cylinder 4 , and are held in position by the magnet 29 .
In the embodiment of FIGS. 12 a and 12 b a card top bar 14 is made from a fibre-reinforced plastics material, for example carbon-fibre-reinforced plastics. In the recess 14 f 1 (see FIG. 5 c ) there is a magnetic tape 29 which is incorporated at the time of manufacture of the card top bar 14 and is thus an integral component of the card top bar 14 . The card top bar 14 can be manufactured, for example, by pressing, drawing, injection-moulding or the like. Provided a mould (matrix) is used, the magnetic strip 29 can be placed into the mould and cast or pressed at the same time. According to FIG. 12 b , the card top clothing 24 1 is arranged in the other recess 14 f 2 (see FIG. 5 c ) and is held in position and fixed by the magnetic tape 29 .
The invention provides simplified accommodation of clothing on the card top bar 14 , which additionally enables damage-free replacement of the strip. The invention enables simplified seating of the clothing strip (carrier layer and wires arranged according to the setting configuration) on the card top bar 14 , which also allows damage-free replacement. For example, in the event of the clothing being worn, the clothing strip to be replaced can be removed easily and the undamaged card top bar 14 with the clothing seating can be used for a new clothing strip. The underside of the clothing strip, on which the spines of the bent wires are located, is held in position by means of a magnet 29 fixed to the card top bar 14 , and thus the clothing strip is fixed to the card top bar 14 ( FIG. 5 a , 5 b ). The clothing strip can additionally be fixed laterally to the side faces of the carrier layer, for example by webs mounted on the card top bar 14 , so providing additional securing/holding of the clothing strip in the horizontal plane of movement. All the clothing strips (e.g. irrespective of the setting configuration) are arranged to be held flexibly by a magnet, so providing the connection to the card top bar. If required, the connection is supported mechanically, e.g. by pieces of sheet metal fastened to the card top bar ( FIG. 6 ). Advantageously additional securing/holding of the clothing strip in the horizontal plane is made possible, for example by the clothing strips being held mechanically by way of webs (e.g. two on the longitudinal sides and optionally two on the tranverse sides). Advantageously, in addition to the use of the clothing strips known in the art, it is also possible to use a modified clothing strip to which there is additionally fastened, by way of a compensating adhesive layer, a piece of sheet metal which is brought into contact with the magnet of the card top bar. Advantages of that compensating and fastening layer and of the additional sheet metal piece are that card tops can be manufactured with greater precision and the surface area of the magnetic contact is increased. In that embodiment it is also possible optionally for the vertical connection to be supported mechanically (according to FIG. 6 ). If required, the clothing strip is preferably additionally provided with e.g. wire claws at its outer edges where there is only carrier layer and none of the wires embedded therein, so increasing the securing of the clothing strip.
Although the foregoing invention has been described in detail by way of illustration and example for purposes of understanding, it will be obvious that changes and modifications may be practised within the scope of the appended claims.
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In an arrangement at a carding machine for cotton, synthetic fibres and the like, at least one card top bar has a carrier and card top clothing. The card top clothing is fastened to the card top bar carrier and is positioned opposite to the clothing of a roller, e.g. the cylinder, and at least the regions of the clothing that face the card top bar carrier are made of a ferrous product, especially steel. In order to enable there to be obtained in simple manner a dimensionally stable clothed card top bar and simpler and more rapid reclothing (clothing replacement), at least one magnetic element is present between the card top bar carrier and the regions of the clothing member that face the card top bar carrier.
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FIELD OF THE INVENTION
This invention relates to millwork building construction members, and more particularly to an improved member of that type and to a method of fabricating such a member.
BACKGROUND OF THE INVENTION
The term millwork refers to formed building construction members that are often rabbeted. Doorjambs, trim pieces and window frame components are representative of millwork.
A doorjamb, for example, which is a structure for receiving a door when closed, typically consists of three members, two vertical "legs" and one horizontal "head" which connects the upper ends of the legs. These doorjamb members have been commonly fabricated from lumber by cutting a single piece to yield the desired rabbeted shape.
When fabricating doorjamb members and the like from lumber, problems result the non-uniformity of the material, e.g., the presence of irregularities such as mixed grains, wood texture variations, moisture content differences, splits and/or knots. Shaping the lumber to achieve the desired configuration can be costly and results in a significant waste of material. Moreover, the cost of lumber of suitable quality has increased substantially in recent years.
To improve the relatively low fire rating of lumber, which is a measure of its ability to withstand a specified temperature for a specified time period, conventional wooden doorjamb members are sometimes given a fire retardant coating or impregnation. Laminated film and paint print coatings or veneers are sometimes applied for decorative purposes. The application of a veneer can be done manually in longitudinal sections, but requires additional fabrication expense, and produces interfaces where delamination could occur later.
Other such members have been formed from aluminum, by an extrusion process, or from steel. However, metal doorjambs are generally more expensive. For aesthetic or decorative reasons and to prevent oxidation, they have been often painted or otherwise covered in a decorative manner, requiring an additional step and higher labor costs in their fabrication. Steel members are difficult to install requiring tools and skill that often are not readily available at the construction site.
A principal objective of the present invention is to provide doorjamb members and other millwork building construction members that are made of relatively inexpensive materials. A further objective is to retain the advantages of conventionally constructed members and providing new solutions to some problems associated with previously known members of this type. A still further objective is to provide an improved method for the fabrication of such members.
SUMMARY OF THE INVENTION
The present invention resides in an improved millwork member for use in construction that accomplishes the above objectives. It includes a non-lumber wood product core, preferably a composition board such as fiberboard, and a thin bendable exterior skin which may be vinyl or acrylic film, aluminum, paper, wood veneer, or another sheet material selected for its decorative or fire-retardant properties.
Internal structural features of the member will be apparent from a method of making the member, this method being another aspect of the invention. First, the skin is bonded to a major surface of a panel that is to form the core. V-shaped grooves are then formed on the side of the panel opposite the skin, thereby dividing the panel into successive parallel rectangular sections. It is best to score the skin slightly when making the grooves. According to a preferred embodiment of the invention in which a doorjamb member is formed, there are five such grooves defining six sections.
Next, the panel is folded, closing the grooves. The skin is thus wrapped around the core and forms the entire exterior surface of the member.
In the case of a rabbeted member that is generally L-shaped, it is preferable to notch one edge of the panel on the side thereof to which the skin is attached. When the panel is folded, this notch receives the opposite end of the panel. Glue can be applied to selected portions of the panel before folding to later hold the panel in its folded position.
If a heat-conducting skin, such as aluminum, is used, a saw cut can be made along one exterior surface of the member, if desired. This break in the skin forms a thermal barrier, and can retain weather stripping if desired.
Other features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a doorway featuring a doorjamb constructed in accordance with the present invention, a fragmentary portion of a door mounted within the jamb being shown;
FIG. 2 is a cross-sectional perspective view of the doorjamb taken along line 2--2 in FIG. 1;
FIG. 3 is a cross-sectional view of the grooved composition board panel from which one member of the doorjamb member is assembled, phantom lines illustrating part of the procedure of folding the panel to yield the assembled doorjamb member; and
FIG. 4 is a cross-sectional view of another doorjamb also constructed in accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A rabbeted doorjamb member 10, shown in FIGS. 1-3 and embodying the present invention, includes a composition board core 12 and a thin exterior skin 14. Three such members 10 can be combined to form the legs and head of one doorjamb, as shown in FIG. 1.
Each member 10 is of a generally L-shaped configuration in cross-section, as best shown in FIG. 2. It has a first door receiving surface 16, parallel to the plane of a door 18 and perpendicular to a second door receiving surface 20. The door receiving surfaces 16 and 20 meet to form an inside corner 22 in which an edge of a door 18 is positioned when closed in the conventional manner.
An entrance surface 24 is perpendicular and adjacent to the first door receiving surface 16, and a back surface 26 extends perpendicular to the entrance surface and parallel to the first door receiving surface. Perpendicular to the back surface 26 in an attachment surface 28 that permits securement of the member 10 to an abutting wall 30. A front surface 32 connects the attachment surface 28 to the second door receiving surface 20, being perpendicular to both.
The internal structural features of the member 10 are best understood from the following description of a method of making the member. First, the exterior skin 14 is bonded to a major surface of the core 12 while the core is in the form of a flat rectangular panel 34. The panel 34 is of a non-lumber wood-product, meaning that although made of wood it is manmade or fabricated industrially and is not simply cut from logs. The preferred material is composition board, which includes particle board, wafer board, oriented strand board and hard board. Fiberboard is a particularly advantageous form of hard board. Exterior plywood is another suitable non-lumber product. The panel material should have a density of not less than 44 pounds per cubic foot. The skin 14 can be chosen for its decorative qualities and may be vinyl, acrylic, paper, a resin impregnated paper such as melamine, aluminum, brass or a wood veneer. A non-wood skin may be imprinted or embossed with a wood grain pattern. A wood veneer should have a depth of at least 0.010 to 0.012. Aluminum skin does not require a depth of more than 0.012. In the case of a composition board panel 34, the skin 14 is applied to a surface that lies perpendicular to the direction in which the panel was pressed when formed.
Five V-shaped grooves 36 are formed in the panel 34 (as shown in FIG. 3) dividing the panel into six elongated, parallel, rectangular sections 38a, b, c, d, e and f. Each groove 36 faces away from the skin 14, the sides of the groove forming ninety-degree angles with each other and forty-five-degree angles with the panel surfaces when the panel 34 is laid flat. The depth of the grooves 36 is such that they extend substantially all the way through the panel 34 to the skin 14. Preferably, the grooves are deep enough to score the skin. For example, a skin of 0.012 inches should be scored to a depth of 0.002 to 0.003 inches.
A notch 40 of rectangular cross-section is formed along one edge 42 of the panel 34 on the side to which the skin 14 is bonded. The grooves 36 and the notch 40 can be formed by a molder cutter head or other cutting tool, as known to those skilled in the art. Glue is applied in the grooves 36 and the notch 40 and on surfaces that are to be mated.
The panel 34 is then folded so that the grooves 36 become closed incisions where adjacent sections 38 are disposed at right angles to each other, as shown in FIG. 2. The notch 40 receives the opposite edge 44 of the panel 34, with the first and third sections 38a and c, which define the second door receiving surface 20 and the attachment surface 28, being pressed against each other. A remaining part of the third section 38c, together with the fourth, fifth and sixth sections 38d, e, and f define an internal cavity 43 of rectangular cross section that extends throughout the length of the member 10. If desired, a staple or tack can be driven through the third section 38c into the opposing edge 44 of the panel 34 to hold the panel in its folded position while the glue dries.
Once the member 10 is assembled, the one-piece skin 14 has been wrapped completely around it, forming all exterior surfaces. Since the skin 14 is bonded to the panel 34, it is bent when the panel 34 is folded and need not be handled separately.
In a second embodiment of the invention, shown in FIG. 4, a doorjamb member 46 is formed which is generally similar to number 10 described above. In this case, however, the skin 48 is aluminum which is a good thermal conductor. To provide a thermal barrier, preventing heat loss from one side of the door to the other, the skin 48 is interrupted by a first shallow groove 50 cut along the attachment surface 52 and a second groove 54 cut along the first door receiving surface 56. The second groove 54 provides the dual function of receiving a conventional weather strip 58.
The cavity formed by the core 60 of the member 46 is filled with a plastic foam 62 for added strength and rigidity. Alternatively, an extruded plastic insert or an insert of any other suitable material can be used.
It will be appreciated from the foregoing that the present invention enables a high quality doorjamb to be constructed of composition board and other inexpensive materials. Waste of materials is minimized and the assembly process is unusually simple and economical.
There are other important advantages that are not so easily apparent. First, it should be noted that many desirable core materials such as particle board present serious screw retention problems. Such materials do, however, have satisfactory screw retention properties if the screw is driven in a direction perpendicular to the core panel 12, i.e., in the direction in which the panel was pressed when formed. According to this invention, a screw driven perpendicular to any exposed major surface of the member 10 or 46 covered by the skin 14 or 48 enters the panel in a direction in which it will be retained satisfactorily.
It should also be noted that the non-lumber materials that are used for the core are of uniform consistency. This eliminates the differential expansion and contraction and attendant warps that might occur if the various sections of the core were made of lumber.
While particular forms of the invention have been illustrated and described, it will be apparent that various modifications can be made without departing from the spirit and scope of the invention.
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A millwork building construction member of rabbeted construction such as a doorjamb which includes a core to which a thin bendable exterior skin is bonded. The core is a non-lumber wood material such as composition board that has been folded after V-shaped grooves have been cut and the skin has been affixed. The skin is thus wrapped around the folded core to form the exterior surface of the member, while a cavity is defined that extends longitudinally through the core. The cavity can be filled for added strength. The skin may be selected for its decorative or fire-retardant properties.
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RELATED APPLICATION DATA
[0001] This patent application is a continuation of U.S. patent application Ser. No. 11/754,919, filed May 29, 2007 (U.S. Pat. No. 7,460,726), which is a continuation of Ser. No. 10/277,617, filed Oct. 21, 2002 (U.S. Pat. No. 7,224,819). The 10/277,617 application is a continuation-in-part of U.S. patent application Ser. No. 09/525,865, filed Mar. 15, 2000 (U.S. Pat. No. 6,611,607), which claims priority to U.S. Provisional Patent Application No. 60/180,364, filed Feb. 4, 2000. The 09/525,865 application is a continuation-in-part of U.S. patent application Ser. No. 09/503,881, filed Feb. 14, 2000 (U.S. Pat. No. 6,614,914). Application Ser. No. 09/503,881 is a continuation-in-part of U.S. patent application Ser. No. 09/186,962 (U.S. Pat. No. 7,171,016), filed Nov. 5, 1998, which is a continuation of U.S. patent application Ser. No. 08/649,419, filed May 16, 1996 (U.S. Pat. No. 5,862,260). Application Ser. No. 08/649,419 is a continuation-in-part of U.S. patent application Ser. No. 08/508,083, filed Jul. 27, 1995 (U.S. Pat. No. 5,841,978) and Ser. No. 08/436,098 (now U.S. Pat. No. 5,636,292), filed May 8, 1995. The 10/277,617 application also claims the benefit of U.S. Provisional Patent Application No. 60/350,082, filed Oct. 19, 2001. Each of the above U.S. patent documents is hereby incorporated herein by reference.
TECHNICAL FIELD
[0002] The invention relates to deriving identifiers from multimedia content. In some cases, the derivation involves, e.g., digital watermarking.
BACKGROUND AND SUMMARY
[0003] Digital watermarking is a process for modifying media content to embed a machine-readable code into the data content. The data may be modified such that the embedded code is imperceptible or nearly imperceptible to the user, yet may be detected through an automated detection process. Most commonly, digital watermarking is applied to media such as images, audio signals, and video signals. However, it may also be applied to other types of data, including documents (e.g., through line, word or character shifting), software, multi-dimensional graphics models, and surface textures of objects.
[0004] Digital watermarking systems have two primary components: an embedding component that embeds the watermark in the media content, and a reading component that detects and reads the embedded watermark. The embedding component embeds a watermark pattern by altering data samples of the media content in the spatial or frequency domains. The reading component analyzes target content to detect whether a watermark pattern is present. In applications where the watermark encodes information, the reader extracts this information from the detected watermark.
[0005] Recently, digital watermarks have been used in applications for encoding auxiliary data in video, audio and still images. Despite the pervasiveness of multimedia content, such applications generally focus on ways to embed and detect watermarks in a single media type.
[0006] One aspect of the invention is a method for decoding auxiliary data in multimedia content with two or more media signals of different media types. This method decodes watermarks in the media signals, uses the watermarks from the different media signals to control processing of the multimedia content. There are many applications of this method. One application is to use the watermark in one media signal to locate the watermark in another media signal. This is applicable to movies where a watermark in one media signal, such as the audio or video track, is used to locate the watermark in another media signal.
[0007] The watermark messages from different media signals may be combined for a variety of applications. One such application is to control processing of the multimedia signal. For example, the combined message can be used to control playback, copying or recording of the multimedia content.
[0008] Watermarks can be decoded such that a watermark decoded from a first media signal of a first media type is used to decode a second media signal. The first and second media signals may be of the same or different types. Also, they may be part of the same composite media signal, such as an audio or video sequence. The term, “composite,” refers to a collection of media signals, which may be temporal portions (e.g., time frames in audio or video), or spatial portions (e.g., blocks of pixels in an image or video frame) of a visual, audio, or audio visual work. As an example, the first media signal may be an audio or video frame (or frames) in an audio or video sequence and the second media signal may be subsequent frames in the same sequence.
[0009] This method may be used in a variety of applications. The watermark in the first media signal may be used to de-scramble, decrypt, or decompress the second media signal. In addition, the watermark in the first media signal may be used to decode a different watermark from the second signal.
[0010] Another aspect of the invention is a method that uses a watermark decoded from a first media signal of a first media type to decode metadata associated with the first media signal. The watermark may be used to locate the metadata, which may be hidden for security purposes. The metadata located from the watermark may be located on the same storage medium that includes the first media signal. For example, the metadata may be located on portable storage device, such as flash memory, a magnetic memory device (e.g., tape or disk), or an optical memory device (e.g., CD, DVD, SACD, minidisk, etc.). The metadata may be located in a file header or some other place (e.g., encoded in the disk wobble).
[0011] There are a variety of applications of the watermark in this context. It may carry a key to decrypt, decompress, descramble, or locate the metadata. The metadata, in turn, may be used to control processing of the media signal in a computer or consumer electronic device. For example, it may be used to control usage rights, playback, recording, copying, transfer, etc.
[0012] Yet another aspect of the invention is a method that decodes first and second watermarks and forms a key for decoding data from the first and second watermarks.
[0013] The watermarks may be decoded from the same or different media signals. For example, the watermarks may be decoded from media signals from the same composite signal. They may be derived from different types of media signals, such as the audio and video tracks of a movie. Alternatively, they may be derived from different parts of the same type of media signal, such as an audio sequence, video sequence, or image. The watermarks may be extracted from a signal or signals stored in a storage device, such as a portable storage device (e.g., optical or magnetic disk or tape, flash memory, etc.).
[0014] The key formed from the watermarks may be used for a variety of applications. It may be used as a watermark key to decode a watermark from a media signal. It may be used as a decryption or de-scrambling key. Also, it may be used a decompression key (e.g., a parameter used to decompress a media signal).
[0015] Further features of the invention will become apparent with reference to the following detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a diagram of a watermark encoder system for encoding watermarks in multimedia content.
[0017] FIG. 2 is a diagram of a watermark decoder system for multimedia data.
[0018] FIG. 3 is a diagram of a watermark decoder system where watermark detectors for different media types collaborate.
[0019] FIG. 4 is a diagram of a watermark decoder system where watermark readers for different media types collaborate.
[0020] FIG. 5 illustrates an operating environment for implementations of the invention.
DETAILED DESCRIPTION
Introduction
[0021] The following sections describe applications for integrating watermarks in multimedia data. In general, these applications exploit some level of interaction between watermarks and/or metadata associated with two or more different media types. The types of media supported in a given implementation vary with the application, and may include, for example, audio (e.g., speech, music, etc.), video, images, graphical models, etc.
[0022] The initial sections describe ways to integrate watermark embedder and detector systems in multimedia data. These techniques may be applied to many different applications, including, for example, copy protection, content authentication, binding media content with external data or machine instructions, etc.
[0023] Later sections discuss specific application scenarios.
Integration of Watermarks and Metadata of Different Data Types
Defining Multimedia
[0024] The term, multimedia, as used in this document, refers to any data that has a collection of two or more different media types. One example is a movie, which has an audio and video track. Or another example is music (or other audio) that has multiple audio channels. Or another example is a combination of audio/video and data (e.g., subtitles, karaoke, text, binary data, source code, etc.). Other examples include multimedia collections that are packaged together on a storage device, such as optical or magnetic storage device. For example, media signals such as still images, music, graphical models and videos may be packaged on a portable storage device such as CD, SACD, DVD, tape, or flash memory card. Different media signals may be played back concurrently, such as the video and audio tracks of a movie, or may be played independently.
Levels of Integration of Watermark Systems
[0025] The extent of integration of watermark systems for different media types ranges from a low level of integration, where watermark decoders operate independently on different media types, to a high level of integration, where the decoders functionally interact. At a low level of integration, the watermark systems for different media types operate on their respective media types independently, yet there is some relationship between the auxiliary data embedded in each type. At a high level of integration, components of the watermark detectors and readers share information and assist each other to perform their respective functions.
[0026] FIG. 1 illustrates an encoder system for embedding messages into multimedia content with two or more media types. One example of multimedia content is a movie with video and audio tracks. For the purpose of illustrating the system, the following sections use a movie as an example of multimedia content. Similar methods may be implemented for other forms of multimedia content, such as combinations of three-dimensional/two-dimensional graphics and animation, audio, video, and still images.
[0027] In the encoder system shown in FIG. 1 , there is a watermark encoder 20 , 22 for each media type. Each encoder may embed a message 24 , 26 into the corresponding media type 28 , 30 in the native domain of the signal (e.g., a spatial or temporal domain) or in some transform domain (e.g., frequency coefficients). The result is multimedia content 32 having watermarks in different media types. The multimedia content 32 may be packaged and distributed on a portable storage device, such as a CD, DVD, flash memory, or delivered electronically from one machine or device to another in a file or streaming format.
[0028] There are a variety of ways to integrate the encoder functions. One way is to use a unified key that controls how a given message or set of messages are encoded and located within the respective media types. Another way is to insert a common message component in two or more different media types. Yet another way is to make a message inserted in one media type dependent on the content of one or more other media types. For example, attributes of an image may be extracted from the image and encoded into an audio track, and similarly, attributes of an audio track may be extracted and encoded in an image. Finally, the message in one media type may be used to control the processing of another media type. For example, copy control flags in a movie's audio track may be used to control copying of the movie's video track or the movie; and, copy control flags in the video track may be used to control copying of the audio track or the movie.
[0029] The following sub-sections describe various scenarios for integrating watermarks in different media types from the perspective of the decoder.
Auxiliary Data Embedded in Different Media Types
[0030] FIG. 2 depicts a framework for low level integration, where watermark decoders 40 , 42 for different media types 44 , 46 operate independently, yet an application 58 uses the auxiliary data associated with each of the media types. The auxiliary data may be encoded in a watermark message within a media signal or may be located in metadata accompanying the media signal (e.g., on the storage device and/or within a header of a file or data packet encapsulating the media). The multimedia content 50 is annotated with a “*” to reflect that it may not be identical to the original version of the content (e.g., the content shown at item 32 , FIG. 1 ) at the time of encoding due to intentional or unintentional corruption (e.g., filtering, compression, geometric or temporal transforms, analog to digital, and digital to analog conversion). A content reader 52 receives the multimedia data and identifies the distinct media types within it. The functionality of the content reader may be built into a watermark decoder or provided by a separate computer program or device. In the example of a movie, the content reader identifies the audio and video tracks.
[0031] Watermark decoders for each media type operate on their respective media data. In extracting the watermark from the signal domain in which the embedder inserted it, the decoder functions compliment the embedder functions. In many applications, the media types may be coded in a standard or proprietary format. In the example of a movie, both the audio and video tracks are typically compressed (e.g., using some lossy transform domain compression codec like MPEG). The watermark decoders may operate on compressed, partially compressed or uncompressed data. For example, the decoders may operate on frequency coefficients in the compressed image, video or audio data. As shown in FIG. 2 , the decoders 40 , 42 operate independently on corresponding media types to extract messages 54 , 56 from watermarks in each media type.
[0032] In the low-level integration scenario of FIG. 2 , an application 58 uses the messages from different media types to process the multimedia content. The application is a device, software process, or combination of a device and software. The specific nature of this processing depends on the requirements of a particular application. In some cases, the message embedded in one media type references content of another type (e.g., link 60 from message 54 to media type 2 ). For example, text sub-titles in a movie may be embedded in the audio track, and may be linked to specific frames of video in the video track via frame identifiers, such as frame numbers or addresses. The application, in this scenario, controls the playback by superimposing the text sub-titles on the linked frames.
[0033] In many applications, it may be useful to insert a link in one media type to content of another media type within the multimedia data. For example, one might want to link a still image or a video texture to a graphical model. Then, a graphics rendering application may use the link to determine which image (or video) to map to the surface of a graphical model. As another example, one might link an audio clip to an image, graphical model or other media object. When instructed to render the image, model or other media object, the rendering application then uses the link to also initiate playback of the linked audio clip, and optionally, to synchronize playback of the linking media signal with the signal linked by the watermark. For example, the video watermark could specify which audio clip to play and when to initiate playback of parts of the audio clip. Stated more generally, the embedded link from one media type to another may be used by the rendering application to control the relationship between the linked media objects during playback and to control the playback process.
[0034] The media signals within multimedia content can be linked together through watermarks and embedded with control information and metadata that is used to control playback. The entire script for controlling playback of a multimedia file or collection may be embedded in watermarks in the media signals. For example, a user could initiate playback by clicking on an image from the multimedia content. In response, the rendering application extracts control instructions, links, and/or metadata to determine how to playback video, audio, animation and other media signals in the multimedia content. The rendering application can execute a script embedded in a watermark or linked via a reference in the watermark (e.g., a watermark message includes a pointer to, or an index or address of a script program stored elsewhere). The watermark message may also specify the order of playback, either by including a script, or linking to a script that contains this ordering. Several media signals may be tied together in a playback sequence via a linked list structure where watermarks embedded in the media signals reference the next media signal to be played back (as well as media signals to be played back concurrently). Each media signal may link to another one by providing a media signal identifier in the watermark message, such as an address, pointer, index, name of media title, etc.
[0035] As the rendering application plays back multimedia content, it can also display metadata about the media signals (e.g., the content owner, a description of the content, time and location of creation, etc.). The watermark messages embedded in the media signals can either include this metadata or link to it. In addition, the watermark messages may include instructions (or a link to instructions) for indicating how and when to display metadata. The metadata need not be in text form. For example, metadata may be in the form of speech output (via a text to speech synthesis system), a pre-recorded audio clip, video clip, or animation.
[0036] To embed a variety of different information, instructions and links into the media signals within multimedia content, the embedder can locate watermark messages in different temporal portions (e.g., time multiplex different messages) of a time varying signal like audio or video. Similarly, the embedder can locate different watermark messages in different spatial portions of images, graphical models, or video frames. Finally, the embedder can locate different watermark messages in different transform domains (e.g., Discrete Fourier Transform, Discrete Cosine Transform, Wavelet transform, etc.) of image or audio signals.
[0037] The following sub-sections describe additional application scenarios.
Copy Protection
[0038] In a copy protection application, the messages embedded in each media type convey information to the application specifying how it may use the content. For example, each message may provide copy control flags specifying “copy once”, “copy no more”, “copy freely”, and “copy never.” These flags indicate whether the application may copy the media type or the multimedia content as a whole, and if so, how many times it may copy the pertinent content.
[0039] Copy control flags can be collected from different media types to determine the extent to which the media types can be copied or selected. For example, a movie may include an audio channel and a video channel. A “copy once” watermark may be embedded in the video channel, with a “copy no more” watermark added to a copy of the movie can be added to the audio track since it may be easier to embed the audio track in real-time for the copy.
Ownership Management
[0040] In multimedia content, each media type may be owned by different entities. The messages embedded in the content may contain an owner identifier or link to an owner. An ownership management application can then collect the ownership information, either from each of the messages in each media type, or by requesting this information by following the link to the owner. For example, the link may be associated with an external database that provides this information. The application may use the link to query a local database for the information. Alternatively, the application may use the link to query a remote database via a wire, wireless, or combination of wire and wireless connections to a remote database on a communication network (e.g., the Internet). One or more intermediate processing stages may be invoked to convert the link into a query to the remote database. For example, the link may be a unique number, index or address that cross-references the URL of a database server on the Internet.
Media Authentication
[0041] An authentication application may use watermark messages and/or metadata to authenticate media signals within the multimedia content. One or more of the media signals in multimedia content may be tampered with. Multimedia content poses an additional problem because media signals may be swapped into the content in place of the original signals. For example, in a video used as evidence, one might swap in a fake audio clip or remove a portion of the audio track. One way to authenticate the media signals is to extract features from them, hash the features, and insert the hashed features into the watermark messages of one or more of the media signals at encoding time.
[0042] To verify authenticity, the application at the decoder side repeats the process of extracting the features from the received media types (e.g., 44, 46), hashing these features, and then comparing the new hash with the hash extracted from the watermark message or messages. The objective of the hash is to create a content dependent parameter that may be inserted into a watermark message, or in some cases, in metadata associated with a media signal. The hash is not necessary if the size of the extracted features is such that they fit within a message.
[0043] Examples of features in images include the location of identifiable objects (such as the location of eyes and noses of human subjects), the shape of objects (e.g., a binary mask or chain code of an object in an image), the inertia of an image, a low pass filtering of an image, the Most Significant Bit of every pixel in a selected color plane (luminance, chrominance, Red, Green, Blue, etc.).
[0044] Examples of features in audio include the temporal location of certain aural attributes (e.g., a transition from quiet to high intensity, sharp transitions in spectral energy, etc.), a low pass filter of an audio clip, etc.
[0045] Features from one media type may be inserted into a watermark or the metadata of another media type. Alternatively, they may be combined and inserted in one or more of the media types in a watermark embedded in a watermark of the media signal or its metadata.
[0046] An additional level of security may be added using public key encryption techniques to create a digital signature that identifies the source of the multimedia content. Some cryptography examples include RSA, DES, IDEA (International Data Encryption Algorithm), skipjack, discrete log systems (e.g., El Gamal Cipher), elliptic curve systems, cellular automata, etc. Public key cryptography systems employ a private and public key. The private key is kept secret, and the public key is distributed to users. To digitally sign a message, the originator of the message encrypts the message with his private key. The private key is uniquely associated with the originator. Those users having a public key verify that the message has originated from the holder of the private key by using the public key to decrypt the message.
Forensic Tracking
[0047] In a forensic tracking embodiment, video content (or media) includes a first watermark signal. (Forensic tracking may involve identifying content and/or tracking a distribution source or history of the content. Forensic tracking may also involve uniquely serializing content to a user or user device. Forensic tracking is particularly helpful in identifying content or a distribution source when the content is discovered in an unexpected or unauthorized channel or location.). The first watermark signal preferably includes a content identifier (“ID”) and, optionally, a distributor ID. The content ID uniquely identifies the content (e.g., with a serial number, unique ID or other multi-bit data). Alternatively, the content ID identifies a class or family of content. The class or family may represent the type of content, e.g., by genre, artists, actors, studio, time period, copyright owner, etc., etc. The distributor ID preferably identifies the content distributor. Examples of a content distributor include a studio, network, company, etc. Alternatively, the distributor ID identifies a distribution channel, medium or protocol.
[0048] The content and distributor IDs can be used as an index to interrogate a data record or database to retrieve information related to content and/or distributor identification. Alternatively, the multi-bit data comprising the identifiers carries sufficient information to allow identification of the content/distributor.
[0049] The first watermark signal is preferably static or unchanging. A static watermark signal enables tracking of the video content item. When video content is found in an unexpected or unauthorized channel or location, the content ID (and optionally the distributor ID, if present) is decoded to identify the content. If a distributor ID is present, it is also extracted (e.g., decoded) from the content and used to identify the distribution source. For example, these IDs are used to query a database to retrieve content or distribution information. Or the multi-bits are decoded to reveal the content or distribution information. Content leaks (or unauthorized distribution) can be traced back to the source. Accordingly, unauthorized distribution or counterfeits, bootlegs, etc. of content items is “forensically” tracked to the misappropriating source via the content/distribution ID.
[0050] In a modified embodiment, the video watermark signal is embedded in a compressed domain. Once compressed, the video content signal is conveyed to an embedding module, which embeds the video watermark signal. Preferably, the video watermark is robust to survive decompression/recompression. In an alternative embodiment, the video watermark is embedded in an uncompressed domain. The video watermark signal preferably survives compression of the watermark signal.
[0051] A second watermark signal is embedded in an audio channel, which is associated with the video content. (For example, MPEG video includes an audio stream. Also, DVD and VHS have designated audio channels. Of course, any format having both a video channel and an audio channel will benefit from this aspect of the present invention. Furthermore, the second digital watermark can alternatively be embedded in subtitle/karaoke content common in DVDs.). The second watermark signal preferably includes a transaction ID. The transaction ID is preferably dynamic, e.g., allowing customization of the transaction ID by individual rendering device (e.g., MP3 player, set-top box, DVD player, VHS, personal computer, network node, receiving stations, etc.). Audio content becomes associated with a user or rendering device via our dynamic transaction ID. Since the multimedia content will typically be associated together, video content can also be associated with a user via the transactional ID embedded in an audio or other auxiliary channel. Although not required, once embedded, the second watermark signal is preferably static.
[0052] Alternatively, the audio channel is digitally watermarked by a broadcaster, repeater or transmitting source, instead of a user or user device.
[0053] In one implementation, the transaction ID is uniquely tailored to a particular transaction in a receipt-like manner. In this implementation, the ID is transaction specific. The transaction ID is optionally associated in a database along with customer, distribution channel, user and/or device information. Alternatively, a transaction ID can be unique to a particular customer. In this case the customer is assigned a unique account number (or other identifier). This customer-specific number is optionally associated with billing information, address, customer rates, content usage rights, distribution channel, etc. A customer's account number is then embedded as or with the transaction ID before (or concurrently as) the video content is rendered to the customer.
[0054] Consider one forensic tracking application. A user downloads content (or rips content from a DVD) including watermarked video and an unmarked audio. The watermarked video preferably includes a static watermark to identify at least the content. A user-rendering device (or the broadcasting device) digitally watermarks the audio associated with the video content. The digital watermark preferably includes a transactional ID. The transactional ID uniquely identifies either the device or the user. Hence, when the content is found in an authorized or unexpected channel the transactional ID is extracted from the audio and used to identify the user or user's rendering device. In this case, the content and/or distributor IDs can be optionally extracted from the video and then used to interrogate an appropriate user database, or to help identify the content. Of course there are many more alternative applications for transactional, content and distributor IDs.
[0055] As an optional arrangement, the audio content is embedded with a third watermark signal as the video/audio content is passed from a first user to a second user. (Or the audio content is watermarked upon receipt by the second user.). The third watermark signal uniquely identifies the second user or second user's device. After such, the audio channel preferably includes both the second and third watermark signals. A distribution trail is formed from the distribution source (via a distribution ID) to the first user (via the audio watermark's transactional ID) to the second user (via the third watermark).
[0056] Like discussed above with respect to the video watermark signal, the audio watermark can be embedded in the audio content in a compressed domain.
[0057] Of course, the content ID could be embedded in an audio channel, while the transactional ID is embedded in a video channel. We note, however, the above content ID in video and transaction ID in audio is preferred since audio embedders are a bit easier to implement in consumer rendering devices or personal computers. As such, a content ID is preferably embedded by a studio or distributor into corresponding video via a professional embedder, potentially a custom hardware device, while an audio transactional ID is embedded by a transaction server, such as a video-on-demand (VOD) PC server, or a user's PC receiving or rendering software.
[0058] As a further implementation, the transactional ID is uniquely associated with the content or distributor ID. In this implementation, the transactional ID and content ID can be cross-correlated for authentication purposes. Or information regarding an expected attribute of the video signal can be embedded in the audio watermark, and/or vice versa.
Integrating Watermark Detection Processes
[0059] Another way to integrate processing of media types is to integrate watermark detectors for different media types. One function of some watermark detectors is to determine the orientation and strength of a watermark within a host media signal. The orientation may provide the watermark location, and possibly other orientation parameters like warp (e.g., an affine or non-linear warp, temporal and/or spatial), scale, rotation, shear, etc. As the media content is subjected to various transformations, the watermark orientation and strength may change. Watermark detectors use attributes of the watermark signal to identify its location and orientation within a host signal. In multimedia content where different media signals are watermarked, detectors for the respective media signals can assist each other by sharing information about the orientation and/or strength of a watermark in the media signals. While the watermarks in different media types may be transformed in different ways, the orientation information found in one media signal might help locate a watermark in a different media signal.
[0060] FIG. 3 depicts a watermark decoder framework in which the watermark detectors for different media types collaborate. Each detector 70 , 72 operates on its respective media type 74 , 76 , yet the detectors share information. The detectors determine the presence, and in some cases, the strength and/or orientation of a watermark in a host media signal. In some applications, such as authentication, the detector identifies portions of the media signal that have a valid watermark signal, and portions where the watermark has been degraded (e.g., the watermark is no longer detectable, or its strength is reduced). Depending on the nature of the host signal, these portions may be temporal portions (e.g., a time segment within an audio signal where the watermark is missing or degraded) or spatial portions (e.g., groups of pixels in an image where the watermark is missing or degraded). The absence of a watermark signal, or a degraded watermark signal, may evidence that the host signal has been tampered with.
[0061] In applications where the watermark carries a message, each detector may invoke a watermark reader 78 , 80 to extract a message from the watermark. In some cases, the reader uses the orientation to locate and read the watermark. The strength of the watermark signal may also be used to give signal samples more or less weight in message decoding. Preferably, each reader should be able to read a watermark message 82 , 84 from a media signal without requiring the original, un-watermarked media signal.
[0062] One example of integrated detection is a scheme where watermark detectors operate on respective media types concurrently and share orientation parameters. To illustrate the scheme, consider the example of a movie that has a watermarked audio and video track. While video and audio are distinct media signals in the content delivery and storage formats, the video and audio tracks are carefully synchronized so that the audio closely tracks the movement of actors' mouths and other motion depicted in the video. The embedding scheme places audio watermarks within a specified temporal range of the video watermarks. Because the video and audio tracks need to be temporally synchronized to avoid noticeable artifacts during playback, the temporal locations of the audio and video watermarks are likely to remain within a predictable temporal distance in their respective host signals. As such, the watermark detectors can take advantage of the temporal relationship of the watermarks in different media types to facilitate detection.
[0063] The location of a watermark detected in one media signal can provide information about the location of a watermark yet to be detected in another media signal. For example, when the video watermark detector finds a watermark in a video frame (e.g., an I frame in MPEG video), it signals the other detector, passing information about the temporal location of the video watermark. Leveraging the temporal relationship between the video and audio watermarks, the audio watermark detector confines its search for an audio watermark to a specified temporal range in the audio signal relative to the location of the corresponding video watermark in the video signal.
[0064] In this scenario, the audio watermark detector may provide similar information to the video watermark detector to help it identify the frame or sequence of frames to be analyzed for a video watermark.
[0065] Another example is a method where one watermark detector operates on a media type, and then passes orientation parameters to a detector of another media type. This scheme reduces the complexity of the second detector because it uses the orientation parameters extracted from a first media type to assist computation of the orientation in another media type. Applying this scheme to the previous example of a movie, the watermark decoder method reduces the complexity of the audio detector by confining its search to a specified range defined relative to the location of a video watermark. This is a simpler case than the previous example in the sense that the orientation information flows from a first detector to a second one. The second detector searches in a confined space around the location specified by the other detector, and does not have to pass orientation information to the other detector. In addition, a detector or calibration signal in one media type can be more robust than another, such that this calibration signal is used to extract the payload from the other media types. For example, in a movie, the audio and video may contain a calibration signal, and the video contains the payload. The video may have been played at a higher rate so the TV station can include more ads (thus, more revenue). It may be hard to read the payload from this time-compressed video, but the higher payload carrying capacity of the video is required so that a content ID can be detected at an interval sufficient, e.g., for interactive TV (e.g., at 1 second intervals). In this example, a watermark in an accompanying audio track can be used to obtain the calibration information, especially since audio watermarks are sometimes embedded in a frequency domain. This calibration information is used to detect the video watermark, especially for a video watermarking technique that embeds different payloads in various frames for increased payload capacity.
Applications of Integrated Watermark Detectors
[0066] As in the previous sections, there are a variety of applications for watermark systems with integrated detectors. The watermarks may be used to encode data or links to external data or other media signals within the multimedia content.
[0067] The watermarks may also be used to encode authentication information. In the movie example, the watermarks in one media type can reference one or more watermarks in another media type. For example, if an audio detector does not find an audio watermark designated by the video watermark to be in a specified range within the audio signal, then it can mark that specified range as being corrupted. Similarly, the video detector can authenticate video frames based on presence or absence of video watermarks designated by audio watermarks.
[0068] In copy control applications for mixed media like movies, integrated detectors can be used to locate audio and video watermarks carrying copy control flags. If the audio or the video tracks have been tampered with or transformed in a way that removes or degrades the watermarks, then a copy control application can take the appropriate action in response to detecting the absence of a watermark or a degraded watermark. The actions triggered in response may include, for example, preventing copying, recording, playback, etc.
Integrating Watermark Message Reading of Different Media Types
[0069] FIG. 4 illustrates yet another scenario for integrating watermark decoders where the watermark readers for different media types collaborate. In this scheme, watermark detectors 100 , 102 for different media types 104 , 106 operate independently (or collaborate as described above) to detect the presence, and optionally the orientation, of watermarks in their respective media types. Watermark readers 108 , 110 then extract messages from the detected watermarks. The watermark readers pool the message data 112 that they extract from the different media types.
[0070] Then, a message decoder 114 attempts to decode the pooled message data. The message decoder may perform various error correction decoding operations, such as Reed Solomon, BCH, Turbo, Convolution operations. In cases where the watermark embedder uses spread spectrum modulation to spread raw message bits in the host media signal into chips, the message decoder may perform the inverse of a spread spectrum modulation function to convert spread spectrum chip values back to raw message values.
[0071] The result of the decoding operations provides information about the media signals. Depending on the application and implementation, the decoded message 116 can be interpreted in different ways. For example, in some cases, to generate a valid decoded message (as indicated by an error detection process such as a CRC or parity check), watermark message data from each media signal must be valid. In other cases, the decoded message may specify which media signals have valid messages, and which do not.
Applications
[0072] Like the other scenarios described above, the scheme for integrating watermark readers of different media types can be applied to many applications, including data embedding and linking, content authentication, broadcast monitoring, copy control, etc. This scheme is particularly suited for content authentication and copy control because it can be used to indicate content tampering and to disable various operations, such as copying, playback, recording, etc. For example, it can be used in a copy control scheme for content with audio and video tracks. Each track contains watermark messages that must be detected and converted to the raw message data 112 before the decoder 114 can decode a valid message. Thus, valid copy control information in both the video and audio tracks must be present before a valid copy control message 116 will be produced. A player can then process the multimedia content based on the control information in the valid copy control message. Alternatively, the content can be prevented from being passed into a player or other application or device if a valid control message is not generated.
Using Watermark Messages to Store Keys to Other Watermarks or Metadata
[0073] The watermark message in one media signal may be used to specify a key of a watermark in another media signal. In this scenario, the watermark reader for one media type supplies the watermark decoder for another media type with the key. This key may specify the location of the watermark as well as information about how to extract the watermark from another media signal, and information to decode or decrypt the watermark message.
[0074] The watermark message in a media signal may also specify a key to access other metadata on the storage device of the media signal. For example, the message may specify a key to decrypt or decode metadata on the storage device, such as metadata in a header file or encoded within tracks of a CD or DVD (e.g., encoded within the disk wobble). The key may also specify the location of the associated metadata.
Applications
[0075] The scheme described in the previous section may be used in many applications, including those discussed previously. This scheme is particularly suited for content authentication and copy protection. In order to authenticate the content, each of the media signals in multimedia content need to have valid watermarks. The watermark in one media signal cannot be located without extracting a key from a watermark in another media signal.
[0076] In copy protection applications, the decoding system would need to find the watermarks in each of the media signals before enabling certain actions (e.g., playback, recording, copying, etc.).
Using Watermark Data in One Media Type to Control Playback of Another Media Type
[0077] For some applications, it is not necessary that each media signal in multimedia content have a watermark. For example, a watermark in one media signal could provide the desired functionality for the entire content, or for selected portions of the content. For example, in copy protection applications for movies, a watermark in the audio track could be used to encode copy control flags to control copying, playback, or recording of audio and/or video tracks.
[0000] Using Watermark Data in Conjunction with Other Data or Applications
[0078] The watermark message data can be used in conjunction with other data or applications to control processing of the multimedia or single media content. Using any of the scenarios above, for example, a decoder can extract a message that is used to control further media processing.
[0079] One example is where the watermark message is used as a necessary key for decoding or decrypting the media content. For example, the watermark message may contain necessary bits for decompressing (e.g., MPEG decoding) of the media signal or signals within the content (audio, video or both). Examples of necessary bits are CRC bits that are required to reconstruct coded video or audio data. This technique is particularly useful when the message is derived from watermark messages embedded in different media signals. In a movie copy control application, for instance, the decoder would have to generate a valid message based on decoding the raw message information from audio and video watermark messages before allowing playback, recording, etc. In this case, the embedder would spread the necessary control information into watermark messages inserted in the audio and video tracks. For example, watermark messages in audio or video frames include decompression parameters or descrambling keys to decompress or descramble subsequent audio or video frames.
[0080] The same approach can be implemented by embedding other forms of control data in one or more watermark messages in different media signals. Another example is a decryption key that is necessary to decrypt other media signals within the content, or other portions of the same media signal. Watermark messages in audio or video frames may include decryption keys to decrypt subsequent frames. One watermark message may include a key, or a portion of a key, needed to decrypt or unscramble other signal portions or other watermark messages. In the case where the watermark message includes only a portion of a key (e.g., one parameter in a key comprising two or more parameters), the other portion may be constructed by extracting another component of the key from another watermark message (in the same or different media signals) or from other metadata (e.g., in the disk wobble, the header file of MPEG content, etc.).
[0081] Another form of control data is region data that indicates that a particular media signal may only be played when the region data of the media signal and the player match. A similar region data scheme is understood to be implemented in the Content Scrambling System currently used for DVDs. The region data can be embedded in one or more watermarks in the same or different media signals. By placing this information in different media signals, the decoder must be able to extract consistent region data from watermarks in each of the media signals as a pre-requisite to further use of the content. Then, assuming all of the region data creates a valid region data message, then the copy control application would control playback based on whether the region data decoded from the watermarks (and/or metadata of the different media signals) matches the region data of the player.
Implementation of Watermark Encoders and Decoders
[0082] The state of watermark encoders and decoders for audio, video and still images is quite advanced. Some examples of watermark systems for multimedia data include U.S. Pat. Nos. 5,862,260, 5,930,369, and U.S. patent application Ser. No. 09/503,881 (now U.S. Pat. No. 6,614,914). Examples of watermark systems targeted to audio signals include U.S. Pat. Nos. 5,945,932, 5,940,135, 6,005,501, and 5,828,325. Other watermark systems are described in U.S. Pat. Nos. 5,940,429, 5,613,004, 5,889,868, WO 99/45707, WO 99/45706, WO 99/45705, and WO 98/54897. Examples of watermark systems used in copy control are: WO 00/04688, WO 00/04712, WO 00/04727, and WO 99/65240. These documents include examples where a copy protection scheme uses watermark data and metadata to control processing of a media signal.
[0083] Watermark systems that operate on compressed content are shown, e.g., in U.S. Pat. No. 5,687,191 and WO 00/04722.
[0084] These watermark systems may be used to implement the scenarios described above.
Location of the Watermark Decoder
[0085] The watermark decoder may be implemented in one or more components. The location of these components varies depending on the application. For multimedia content on portable memory devices like DVDs or CDs, the decoder may be implemented in the drive hardware or in an interface to the drive hardware. Alternatively, the decoder may be located in an application program or device. One example is a media codec, like an MPEG codec. If the media signals are compressed, the detector may have to implement at least portions of the codec. For example, if the watermark is coded in frequency coefficients in MPEG video and audio, the decoder system may include an MPEG parser and dequantizer to identify the media signals (audio and video signals) and extract the coefficients from each of the media signals. Placing the watermark decoder in the media codec, such as the MPEG codec, saves resources because many of the resources used for decoding the media signals may also be used for detecting and reading the watermarks.
Operating Environment
[0086] FIG. 5 illustrates an example of a computer system that may serve as an operating environment for software implementations of the watermarking systems described above. The encoder and decoder implementations as well as related media codecs and applications may be implemented in C/C++, Java, or other suitable programming languages and are portable to many different computer systems. Components may also be implemented in hardware devices or in a combination of hardware and software components. These components may be installed in a computing device such as a Personal Digital Assistant, Personal Computer, Hand-held media player, media players (DVD players, CD players, etc.) or implemented in a hardware module such as an integrated circuit module, ASIC, etc. FIG. 9 generally depicts one example of an operating environment for encoder and decoder systems.
[0087] The computer system shown in FIG. 9 includes a computer 1220 , including a processing unit 1221 , a system memory 1222 , and a system bus 1223 that interconnects various system components including the system memory to the processing unit 1221 .
[0088] The system bus may comprise any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using a bus architecture such as PCI, VESA, Microchannel (MCA), ISA and EISA, to name a few.
[0089] The system memory includes read only memory (ROM) 1224 and random access memory (RAM) 1225 . A basic input/output system 1226 (BIOS), containing the basic routines that help to transfer information between elements within the computer 1220 , such as during start-up, is stored in ROM 1224 .
[0090] The computer 1220 further includes a hard disk drive 1227 , a magnetic disk drive 1228 , e.g., to read from or write to a removable disk 1229 , and an optical disk drive 1230 , e.g., for reading a CD-ROM or DVD disk 1231 or to read from or write to other optical media. The hard disk drive 1227 , magnetic disk drive 1228 , and optical disk drive 1230 are connected to the system bus 1223 by a hard disk drive interface 1232 , a magnetic disk drive interface 1233 , and an optical drive interface 1234 , respectively. The drives and their associated computer-readable media provide nonvolatile storage of data, data structures, computer-executable instructions (program code such as dynamic link libraries, and executable files), etc. for the computer 1220 .
[0091] Although the description of computer-readable media above refers to a hard disk, a removable magnetic disk and an optical disk, it can also include other types of media that are readable by a computer, such as magnetic cassettes, flash memory cards, digital video disks, and the like.
[0092] A number of program modules may be stored in the drives and RAM 1225 , including an operating system 1235 , one or more application programs 1236 , other program modules 1237 , and program data 1238 .
[0093] A user may enter commands and information into the personal computer 1220 through a keyboard 1240 and pointing device, such as a mouse 1242 . Other input devices may include a microphone, sound card, radio or television tuner, joystick, game pad, satellite dish, digital camera, scanner, or the like. A digital camera or scanner 43 may be used to capture the target image for the detection process described above. The camera and scanner are each connected to the computer via a standard interface 44 . Currently, there are digital cameras designed to interface with a Universal Serial Bus (USB), Peripheral Component Interconnect (PCI), and parallel port interface. Two emerging standard peripheral interfaces for cameras include USB2 and 1394 (also known as firewire and iLink).
[0094] In addition to a camera or scanner, watermarked images or video may be provided from other sources, such as a packaged media devices (e.g., CD, DVD, flash memory, etc), streaming media from a network connection, television tuner, etc. Similarly, watermarked audio may be provided from packaged devices, streaming media, radio tuner, etc.
[0095] These and other input devices are often connected to the processing unit 1221 through a port interface 1246 that is coupled to the system bus, either directly or indirectly. Examples of such interfaces include a serial port, parallel port, game port or universal serial bus (USB).
[0096] A monitor 1247 or other type of display device is also connected to the system bus 1223 via an interface, such as a video adapter 1248 . In addition to the monitor, personal computers typically include other peripheral output devices (not shown), such as speakers and printers.
[0097] The computer 1220 operates in a networked environment using logical connections to one or more remote computers, such as a remote computer 1249 . The remote computer 1249 may be a server, a router, a peer device or other common network node, and typically includes many or all of the elements described relative to the computer 1220 , although only a memory storage device 1250 has been illustrated in FIG. 9 . The logical connections depicted in FIG. 9 include a local area network (LAN) 1251 and a wide area network (WAN) 1252 . Such networking environments are commonplace in offices, enterprise-wide computer networks, intranets and the Internet.
[0098] When used in a LAN networking environment, the computer 1220 is connected to the local network 1251 through a network interface or adapter 1253 . When used in a WAN networking environment, the personal computer 1220 typically includes a modem 1254 or other means for establishing communications over the wide area network 1252 , such as the Internet. The modem 1254 , which may be internal or external, is connected to the system bus 1223 via the serial port interface 1246 .
[0099] In a networked environment, program modules depicted relative to the personal computer 1220 , or portions of them, may be stored in the remote memory storage device. The processes detailed above can be implemented in a distributed fashion, and as parallel processes. It will be appreciated that the network connections shown are exemplary and that other means of establishing a communications link between the computers may be used.
[0100] In one implementation, a watermark embedder or detector operates in software as part of the operating system (OS) or plug-in for an application or multimedia layer of the OS. The watermark embedder or detector can be alternatively implemented in hardware as part of a graphics card, network card, sound card, CPU, motherboard chipset, or video recording card. Or the embedder or detector can be implemented with a software controller that uses hardware specific pieces to optimally process the watermark.
[0000] Relationship with Other Applications of Metadata
[0101] Watermarks can facilitate and cooperate with other applications that employ metadata of multimedia objects. As demonstrated above, this is particularly true in copy protection/control applications where the copy control information in the watermark and the metadata are used to control playback. The watermark message and metadata (in the MPEG file header or encoded in the disk wobble) can form components in a unified key that is a necessary prerequisite to playback or some other use of the content.
[0102] The watermarks in the media signals can each act as persistent links to metadata stored elsewhere, such as a metadata database server on the Internet or some other wire or wireless network. Applications for viewing and playing content can display metadata by extracting the link and querying a metadata database server to return the metadata (e.g., owner name, content description, sound or video annotation, etc.). The watermark decoder or an application program in communication with it can issue the query over the Internet using standard communication protocols like TCP/IP, database standards like ODBC, and metadata standards like XML. The query may be sent to a metadata router that maps the link to a metadata database server, which in turn, returns the metadata to the viewing application for display or playback to the user.
Concluding Remarks
[0103] The watermarking technology detailed herein can be employed in numerous diverse applications. See, e.g., the applications for watermarking detailed in commonly-owned U.S. Pat. No. 5,862,260, and copending application Ser. Nos. 09/292,569, 60/134,782, 09/343,104, 09/473,396, 09/476,686, and 60/141,763.
[0104] Having described and illustrated the principles of the invention with reference to several specific embodiments, it will be recognized that the principles thereof can be implemented in other, different, forms.
[0105] To provide a comprehensive disclosure without unduly lengthening the specification, applicant incorporates by reference the patents and patent applications referenced above.
[0106] The particular combinations of elements and features in the above-detailed embodiments are exemplary only; the interchanging and substitution of these teachings with other teachings in this and the incorporated-by-reference patents/applications are also contemplated.
[0107] In view of the wide variety of embodiments to which the principles of the invention can be applied, it should be recognized that the detailed embodiment is illustrative only and should not be taken as limiting the scope of the invention. Rather, we claim as our invention all such embodiments as may come within the scope and spirit of the following claims, and equivalents thereto.
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The presently claimed invention relates generally to content identification, such as deriving identifiers from content itself. One claim recites a method including: using a processor, deriving first information from audio elements of an audio signal; using a processor, deriving second information from data representing picture elements of a video signal that is associated with the audio signal; and utilizing the first information or the second information in a content filtering process, said process utilizes a recognition unit or device to sample content being distributed on a network, and controls further distribution of the content in the network based at least in part on the first information or the second information. Of course, other combinations and claims are provided as well.
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BACKGROUND OF THE INVENTION
The present invention relates to a process for producing a laminated sheet comprising an alumina fiber precursor spun out from a spinning solution containing an aluminum compound. More particularly, it relates to a process for producing a laminated sheet comprising an alumina fiber precursor having a uniform basis weight throughout. Alumina fiber sheet obtained by calcining the said laminated sheet has excellent refractory and heat insulating properties as well as high mechanical strength and chemical stability even under high temperatures and are used as a high-temperature refractory/heat insulator, high-temperature cushioning medium and such.
It is known to produce alumina fiber by first forming an alumina fiber precursor by spinning from a spinning solution, and then calcining the said precursor. This method is especially suited for producing alumina fiber whose alumina content exceeds 65% by weight, such the production that the conventional melt fiber-forming method is inapplicable. The spinning solution used in this method is principally comprising an aluminum compound and contains small amounts of various adjuvants. The adjuvants include those which become the structural elements of the finally produced alumina fiber, such as metal compounds, and those which serve for adjusting the properties of the spinning solution, such as water-soluble polymeric compounds. For example, a spinning solution prepared by adding silica sol and polyvinyl alcohol to a basic aluminum chloride solution formed by dissolving aluminum in hydrochloric acid is used.
Blowing method and spindle method utilizing centrifugal force are known for spinning out an alumina fiber precursor from a spinning solution, but usually blowing method is used. According to this blowing method, the spinning solution is supplied into a high-speed spinning air stream from a nozzle, the supplied spinning solution being drawn out in the spinning air stream, deprived of moisture and solidified to form an alumina fiber precursor.
The thus formed alumina fiber precursor is amassed to form an alumina fiber precursor sheet having a specified basis weight, i.e., a specified weight per unit area. Although the constituent alumina fiber precursor has flexibility, the precursor sheet itself is low in fiber strength and also unstable as it contains structural water and/or additives in fiber, so that usually this precursor sheet, can not be offered as a commercial product in the form as it is. Therefore, it is necessary to calcine the alumina fiber precursor sheet to form an alumina fiber sheet having high crystallinity while maintaining a stable oxide state. It is also possible to obtain an alumina fiber sheet with even higher mechanical strength by needling the precursor sheet before calcining. (See U.S. Pat. Nos. 4,752,515, 4,931,239 and 5,104,713).
As means for producing an alumina fiber precursor sheet having a specified basis weight (fiber weight per unit area or basis area weight) by amassing the alumina fiber precursor, a method is known in which the alumina fiber precursor in the spinning air stream is fallen and stacked on an accumulator until a sheet with a specified basis weight is formed. For example, the alumina fiber precursor is fallen and stacked on a rotating endless belt, and the alumina fiber precursor sheet formed by stacking the said precursor is successively tugged out from the endless belt.
A method is also known in which the alumina fiber precursor carried in the spinning air stream is fallen and stacked on an accumulator to form a thin lamina sheet which is far smaller in thickness than the sheet to be formed having a specified basis weight, and this lamina sheet, in the next step, is wound round a number of times until forming the sheet with a specified basis weight. In a typical example of this method, a spinning air stream containing the alumina fiber precursor is let impinge almost at right angles against a rotating endless belt of the type which allows easy passage of air, such as a belt made of (metal) wire mesh (net). The spinning air stream is allowed to pass through the endless belt, but the alumina fiber precursor is caught and amassed on the endless belt to form a lamina sheet. This lamina sheet of alumina fiber precursor is pulled apart from the endless belt and wound around a rotator in whatever layers until forming a sheet having a specified basis weight. Then the roll of the laminated sheet on the rotator is cut into sections, and subjected to the ensuing steps such as calcining.
According to the above method, although capture and amassing of the alumina fiber precursor from the spinning air stream is easy, the sheet forming operations are complicated as they are batch type, and further, since the length of the sheet that can be treated depends on the circumferential length of the rotator, it is impossible to obtain sheets of all required lengths.
A further problem of the said conventional method is that the formed alumina fiber precursor sheet is non-uniform in basis weight along the width thereof, the basis weight being particularly small at both end portions of the sheet. This is for the reason that when the alumina fiber precursor is fallen from the spinning air stream and stacked on an accumulator, the precursor does not stack uniformly along the whole width of the accumulator, and most remarkably the stacking at both ends in the width direction is relatively small.
That the basis weight of the alumina fiber precursor sheet is non-uniform along the width thereof, particularly small at both ends, signifies corresponding variation of the basis weight of the calcined alumina fiber sheet in its width direction. An alumina fiber sheet as a commercial product is required to be uniform in basis weight in its entirety, so that both end portions in the width direction where the basis weight is smaller than the specified value must be cut out rather overly, which results in a reduced yield of the alumina fiber sheet. Also, even if both end portions are cut out, the sheet would have to be disposed off as a substandard product if there still exists a portion where the basis weight is outside the specified range.
In recent years, attention is focused on application of alumina fiber sheets to such areas as holding means for exhaust gas cleaning systems, heat-resistant filters and the like, and in such uses, higher precision of sheet thickness than in the conventional uses is required. For example, in the internal combustion engines, as a measure for disposal of exhaust gas, a cleaning system having a honeycomb catalyst housed in a casing is provided in the exhaust gas passage. For securely holding such honeycomb catalyst in the catalyst casing, it is necessary to wind a holding mat for catalyst holding member around the honeycomb catalyst to as much a uniform thickness as possible and house this catalyst in the casing so that it will be closely secured to the inside wall of the casing by the restoring force of the holding member. Such a holding member is preferably a fiber sheet which is proof against fiber deterioration and capable of maintaining an appropriate surface pressure even under high temperatures. Japanese Patent Application Laid-Open (KOKAI) No. 7-286514, for instance, teaches that among alumina fiber sheets, the one produced by laminating alumina fiber having a composition of Al 2 O 3 :SiO 2 =70-74:30-26 (by weight) and needling the laminate is especially preferred.
As a result of the present inventors' earnest studies to solve the above problem, it has been found that by folding the thin lamina sheet of alumina fiber precursor by a predetermined width while stacking the folded sheet and continuously moving the stacking sheet in the direction orthogonal to the folding direction, the obtained alumina fiber precursor sheet has uniform basis weight along the full width thereof.
The present invention has been attained on the basis of the above finding.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a process for producing an alumina fiber precursor sheet which is uniform in basis weight along the full width thereof.
To attain the above aim, in the first aspect of the present invention, there is provided a process for producing a laminated sheet comprising an alumina fiber precursor, which process comprises spinning out an alumina fiber precursor from a solution mainly comprising an aluminum compound, falling and stacking said alumina fiber precursor on the surface of an accumulator to form a thin lamina sheet of alumina fiber precursor, continuously pulling out said lamina sheet from the accumulator, transferring the resultant lamina sheet to a folding device, and folding the sheet by a predetermined width while stacking the folded sheet and continuously moving the stacking sheet in the direction orthogonal to the folding direction.
In the second aspect of the present invention, there is provided a process for producing an alumina fiber sheet which comprises calcining a laminated sheet of alumina fiber precursor obtained from a process according to the first aspect.
In the third aspect of the present invention, there is provided a holding mat for catalyst holding member, which comprises an alumina fiber sheet produced by needling and calcining a laminated sheet of alumina fiber precursor obtained from a process comprising spinning out an alumina fiber precursor from a solution mainly comprising an aluminum compound, falling and stacking said alumina fiber precursor on the surface of an accumulator to form a thin lamina sheet of alumina fiber precursor, continuously pulling out said lamina sheet from the accumulator, transferring the resultant lamina sheet to a folding device, and folding the sheet by a predetermined width while stacking the folded sheet and continuously moving the stacking sheet in the direction orthogonal to the folding direction.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic flow sheet illustrating an embodiment of the present invention.
FIG. 2 is a schematic illustration of a folder system usable in carrying out the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in detail below.
In the present invention, preparation of the spinning solution and formation of the alumina fiber precursor can be accomplished according to the conventional methods. For example, the spinning solution can be prepared by forming a basic aluminum chloride solution by dissolving aluminum in hydrochloric acid, and adding silica sol to the solution so that the finally obtained alumina fiber will have a composition of Al 2 O 3 :SiO 2 =preferably 65˜98:35˜2, more preferably 70˜97:35˜3 (by weight). When the silicon content increases excessively, although it becomes easy to form fibers, heat resistance lowers excessively, while a too small silicon content make the fibers fragile. In order to improve spinnable properties, it is preferable to add a water-soluble organic polymer such as polyvinyl alcohol, polyethylene glycol, starch, cellulose derivatives or the like. In some cases, the solution is properly concentrated to adjust the viscosity usually to 10 to 100 poise.
Blowing method, in which the spinning solution is supplied into a high-speed spinning air stream, is preferably used for forming alumina fiber precursor from the spinning solution. The nozzles usable in the blowing method include two types: in one type, a spinning solution nozzle is provided in an air stream nozzle which generates a spinning air stream; in the other type, a spinning solution nozzle is provided so as to supply the spinning solution externally to the spinning air stream. Both types can be used in the present invention. In case where spinning is carried out according to the said blowing method, preferably an endless belt made of metal gauze is set substantially at right angles against the spinning air stream, and the spinning air stream containing the formed alumina fiber precursor is let impinge against the rotating belt. The alumina fiber precursor formed by the said spinning is usually about several micrometers (μm) in diameter and several ten to several hundred mm in length.
The thin lamina sheet of alumina fiber precursor formed on the accumulator is successively pulled out from the accumulator and transferred to a folder by which the sheet is folded to a predetermined width and amassed, and the amassed sheet is continuously moved in the direction orthogonal to the folding direction. In other words, the lamina sheet is successively pulled apart from the accumulator, folded and stacked in the advancing direction of the sheet, and continuously moved transversely to the folding direction. Therefore, the folded sheet width becomes equal to the width of the laminated sheet to be formed. Thereby both end portions in the width direction of the lamina sheet are dispersed in the formed laminated sheet, so that the basis weight of the laminated sheet becomes uniform throughout the sheet.
The basis weight of the lamina sheet should at least be enough to form a thinnest allowable sheet; it is usually 10 to 200 g/m 2 , preferably 30 to 100 g/m 2 . This thin lamina sheet is not necessarily uniform in both of its crosswise and longitudinal directions, so that the laminated sheet is formed by laminating the lamina sheet in at least 5 layers, preferably 8 or more layers, more preferably 10 to 80 layers. By this lamination, local non-uniformity of the lamina sheet is countervailed, so that it is possible to obtain a laminated sheet having a uniform basis weight throughout. The number of laminations is not specifically limited, but it is to be noted that a too large thickness of the sheet may make it unable to obtain preferred improvement of peel strength in the thickness direction by needling normally conducted in a later step, or may cause a reduction of sheet productivity.
For forming the laminated sheet, the lamina sheet is delivered out continuously from the accumulator and transferred to a folder whereby the sheet is folded to a predetermined width, stacked and continuously moved in the direction orthogonal to the folding direction. For example, in the accumulator, alumina fiber precursor is stacked on a metal gauze-like rotating endless belt to form a thin lamina sheet, and this sheet is separated from the endless belt and forwarded to the folder. In this folder, the sheet is folded to a predetermined width and piled up on an endless belt rotating in the direction substantially orthogonal to the folding direction. The number of laminations of the laminated sheet depends on the moving speed of the endless belt. Slow speed increases the number of laminations, while fast speed decreases the number of laminations.
FIG. 1 is a schematic flow sheet illustrating an embodiment of the present invention. In this embodiment, there is used a folding system 3 comprising an endless belt 1 for carrying the lamina sheet 2 , another endless belt 5 for carrying the laminated sheet, said endless belt 5 being disposed at a position lower than the endless belt 1 and in the direction transverse thereto, and a folding means by which the lamina sheet hanging from the rear end of the endless belt 1 is folded and stacked on the endless belt 5 . In this folding system 3 , the folding means is arranged movable laterally, and the width of the laminated sheet is decided by the range of travel of the folding means. Use of such folding system makes it possible to continuously produce a laminated sheet 4 of any optional width from the continuously transferred thin lamina sheet.
The folding system usable in the present invention is not limited to the structure illustrated in FIG. 1; it is possible to use a vertical folding system such as illustrated in FIG. 2 .
The thus produced laminated sheet of alumina fiber precursor is then calcined by a conventional method and thereby made into an alumina fiber sheet. Calcining is carried out usually at a temperature not lower than 500° C., preferably 1,000 to 1,300° C. When the laminated sheet is subjected to needling before calcining, it is possible to obtain an alumina fiber sheet with high mechanical strength in which the alumina fibers are also oriented in the thickness direction. Needling is conducted usually at a rate of 1 to 50 stitches/cm 2 . Generally, the higher the needling rate is, the higher become the bulk density and peel strength of the obtained alumina fiber sheet.
According to the present invention, it is possible to produce a laminated sheet of alumina fiber precursor having a uniform basis weight throughout. By calcining this laminated sheet by a conventional method after needling, if necessary, there can be obtained an alumina fiber sheet having a uniform basis weight throughout. Further, the present invention enables continuous production of alumina fiber sheet of any optional length with ease and can remarkably improve production efficiency over the conventional methods.
EXAMPLES
The present invention is described in further detail by showing the examples thereof, which examples however are merely intended to be illustrative and not to be construed as limiting the scope of the invention.
Example 1
To an aqueous solution of basic aluminum chloride (aluminum content: 70 g/l, Al/Cl=1.8 (atomic ratio)) was added silica sol so that the finally obtained alumina fibers would have a composition of Al 2 O 3 :SiO 2 =72:28 (by weight). After further adding polyvinyl alcohol, the mixed solution was concentrated to prepare a spinning solution having a viscosity of 40 poises and an alumina/silica content of about 30% by weight, and spinning thereof was carried out with this spinning solution according to the blowing method. A spinning air stream carrying the thus formed alumina fiber precursor was let impinge against a metal gauze-made endless belt, thereby capturing and amassing the alumina fiber precursor to obtain a 1,050 mm wide thin sheet thereof with a basis weight of 40 g/m 2 , which was relatively non-uniform and had the alumina fiber precursor arranged randomly in the plane.
This thin sheet of alumina fiber precursor was folded and stacked using a folding device of a structure shown in FIG. 1 to produce a continuous 950 mm wide laminated sheet of alumina fiber precursor comprising 63 layers of folded lamina sheet. This laminated sheet was calcined by first placing it under 300° C. for 2 hours, then successively raising the temperature to 300˜550° C. at a rate of 2° C./min and then to 550˜1,250° C. at a rate of 5° C./min, and finally leaving it under 1,250° C. for 30 minutes to make a continuous alumina fiber sheet measuring about 25 mm in thickness and about 650 mm in width. This alumina fiber sheet was cut to a width of 600 mm and both end portions comprising the turnups were removed. A 2,000 mm portion of this alumina fiber sheet was divided into 6 equal sections in the width direction and into 20 equal sections in the longitudinal direction, and the basis weight of each section was measured. The mean value of basis weight in the width direction of the longitudinally eicosasected sections and the tripled value (3σ/mean value of basis weight×100; %) of its standard deviation were determined. The scatter determined by averaging the determinations in the longitudinal direction (n=20) was 7.7%.
COMPARATIVE EXAMPLE 1
A thin lamina sheet obtained according to the same procedure as in Example 1 was wound around a round rotator to produce a 1,050 mm wide laminated sheet of alumina fiber precursor comprising 63 layers of the lamina sheet, and this laminated sheet was calcined to obtain an approximately 40 mm thick and approximately 740 mm width alumina fiber sheet. This alumina fiber sheet was cut to a width of 600 mm and subjected to the same test as said above. The scatter determined in the same way as in Example 1 was 17.4%.
Example 2
A thin lamina sheet with a basis weight of 40 g/m 2 and a width of 1,050 mm obtained in the same way as in Example 1 was folded, stacked and separated at a higher rate than in Example 1 to produce a 950 mm wide continuous laminated sheet of alumina fiber precursor comprising 30 layers of the lamina sheet. To this laminated sheet was sprayed 30 ml/kg of a 10 wt % higher fatty acid ester/mineral oil solution as a lubricant, after which the sheet was subjected to needling at a rate of 5 stitches/cm 2 and then calcined in the same way as in Example 1 to make a continuous alumina fiber sheet having a thickness of about 10 mm and a width of 650 mm. Evaluations of this alumina fiber sheet by the same method as used in Example 1 showed a scatter of 6.7%.
In order to evaluate suitability of the obtained alumina fiber sheet for use as a holder for exhaust gas cleaning systems, five 50 mm×50 mm square test pieces were collected from the sheet by cutting it in the width direction at equal intervals, and each test piece was subjected to 5-time repetition of a compression/release operation which comprised compressing the test piece to a thickness of 4 mm at room temperature by a compression tester, measuring the surface pressure and then releasing the compression. Each test piece was also subjected to 5-time repetition of a compression/release operation which comprised compressing the test piece to a thickness of 3 mm, measuring the surface pressure and releasing the compression. The results of the above evaluation tests are shown in Table 1.
COMPARATIVE EXAMPLE 2
A thin lamina sheet obtained in the same way as in Comparative Example 1 was wound around a round rotator to produce a 1,050 mm wide laminated sheet of alumina fiber precursor comprising 30 layers of the said lamina sheet, and this laminated sheet was needled and calcined as in Example 1 to obtain an alumina fiber sheet having a thickness of about 10 mm and a width of about 740 mm. The scatter of this alumina fiber sheet as determined in the same way as described above was 16.8%.
Suitability of the obtained alumina fiber sheet for use as a holder for exhaust gas cleaning systems was evaluated in the same way as in Example 2, the results are shown in Table 1. Comparing Example 2 and Comparative Example 2, both are high in surface pressure, which is little reduced even if thickness alteration is repeated, and both are also high in restorative force of fibers and suited for use as a holder. However, it is remarkable that Example 2 is small in scatter of surface pressure properties between the sheets than Comparative Example 2, and particularly suited for use as a holder material.
TABLE 1
Example 2
Comp. Example 2
Compression thickness
4 mm
3 mm
4 mm
3 mm
Surface pressure (after
1st/5th application of
compression, kg/cm 2 )
Test piece 1
1.5/1.3
3.9/3.8
1.0/1.0
2.8/2.8
Test piece 2
1.4/1.3
3.7/3.7
1.6/1.5
3.9/3.8
Test piece 3
1.6/1.5
4.0/3.9
1.1/1.0
2.9/2.8
Test piece 4
1.5/1.4
3.8/3.7
1.7/1.5
4.3/4.1
Test piece 5
1.6/1.5
4.1/4.0
2.5/2.1
5.2/4.7
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The present invention relates to a process for producing a laminated sheet comprising an alumina fiber precursor, which process comprises spinning out an alumina fiber precursor from a solution mainly comprising an aluminum compound, falling and stacking said alumina fiber precursor on the surface of an accumulator to form a thin lamina sheet of alumina fiber precursor, continuously pulling out said lamina sheet from the accumulator, transferring the resultant lamina sheet to a folding device, and folding the sheet by a predetermined width while stacking the folded sheet and continuously moving the stacking sheet in the direction orthogonal to the folding direction.
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This application is a continuation-in-part application of my prior application Ser. No. 455,897 filed Mar. 28, 1974, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates generally to machinery for the production of ornamentally patterned pile fabrics, and particularly to the formation of nonwoven pile fabrics which are produced by needling pile fibers into a supporting web with the fibers arranged thereon in a particular pattern corresponding to the ornamental arrangement desired. The invention also concerns a particular method for producing such pile fabric and a needling machine for performing the method.
Prior art methods for the production of needled, ornamentally patterned, nonwoven pile fabrics are known, for example, from U.S. Pat. No. 3,705,064, wherein at least two nonwoven fabric webs strengthened by a needling operation are used to form the finished fabric. Patterning is achieved by joining together fabric webs which are solid colored or which comprise mixed colors with one of the webs being printed on one side with pigment dyes to form an ornamental pattern. The printed side of one nonwoven fabric web is arranged to face away from the unprinted side of the other nonwoven fabric web, and the webs are subsequently subjected to a needling operation from the unprinted surface so that the fibers of the unprinted web blend with the fibers of the printed web to thereby form a nap upon the printed area. In this manner, a printed ornamental pattern is produced with a soft, patterned 3-dimensional effect.
In another prior art method known from German Pat. No. 1,960,753, a patterned nonwoven needled fabric is produced by application of a glue upon side of a solid colored needled fabric web with the desired ornamental pattern penetrating into the web. After it is dried, this web is placed with the side remote from the glued side against a second differently colored needled web having mixed or contrasting colors, with both the webs being jointly needled from the glued side. In this method, the ornamental pattern is obtained by needling fibers on the unglued side of the glued web through the web to be patterned so that a pattern is formed on the visible surface appearing thereon as a finished nap. However, in the range of the glued areas, the web which is ornamentally patterned with the glue is only partially needled with the web which is to be patterned.
In still another known method according to German Pat. No. 1,960,363, production of a patterned and needled nonwoven fabric is accomplished by utilizing two solid colored or mixed colored nonwoven fabric webs which are strengthened by needling with one of the webs being printed with a differently colored pattern and with the webs being placed one upon another and needled through from the printed web side so that the fibers colored by the printing penetrate to the outer surface of the unprinted web thereby forming a visible pattern on the nonwoven fabric. A product produced by this method has upon the originally unprinted visible side the pattern of the printed rear web, with the entire visible surface having a naplike appearance due to the needling process which is effected over the entire area. Both the unprinted fibers and those which are colored by the printing process appear on the visible side and thereby produce upon the visible surface the ornamental pattern which is printed on the back of the web.
It has also been known in the prior art to print a desired ornamental pattern directly upon the visible side of a web. This, however, involves a considerable disadvantage inasmuch as when such a nonwoven fabric is used as a floor covering, the ornamental pattern will be worn off within a relatively short time due to the fact that the pattern lacks the depth which is achieved by some of the previously mentioned prior art methods. Furthermore, because the fabric is printed directly upon the visible side it loses its nappy appearance due to the printing process.
Most known methods for the production of ornamentally-patterned nonwoven fabrics involve disadvantages by virtue of the fact that several operations are required for the production of the ornamental pattern. Printing of the pattern on one side or the other of one or more of the webs which are utilized is necessary and the webs must be subsequently needled and, as in one of the known methods, glue must be applied in the form of the ornamental pattern to be achieved. Apart from the time consuming operations which are required to form the ornamental pattern by application of printing ink or glue, such known methods involve further disadvantages since considerable amounts of glue and ink must be used.
In view of the foregoing, attempts have been made in accordance with German Pat. No. 1,977,417 to produce an ornamental pattern by utilizing needles which are arranged in the form of the pattern to be effected with two differently dyed nonwoven fabric webs being placed one upon the other and then needled through only within the range of the area where the ornamental pattern is to be achieved. In this approach, the fibers of the second web which are of a different color become visible in accordance with the arrangement of the needles upon the visible side of the web. However, a disadvantage arises in this situation inasmuch as the two webs are only needled in the range or area where the ornamental pattern is desired and no needling is effected in areas or regions which are to be free of the ornamental design. A further disadvantage resides in the fact that only solid colored ornamental patterns can be produced thereby rendering patterns having multicolored configurations unattainable.
In view of the foregoing, the present invention, which proceeds from the last-mentioned method for the production of ornamentally patterned nonwoven fabrics involving needling of fibers into a supporting web only in the area corresponding to the ornamental pattern to be achieved, is intended as an improvement over such methods whereby there may be developed an approach which permits achievement of multicolored patterns and which allows the entire surface area of a nonwoven fabric to be needled during the production process.
SUMMARY OF THE INVENTION
In accordance with the present invention, the production of ornamentally patterned nonwoven fabrics is performed by applying loose, staple fibrous material of a particular color upon a solid-colored or mixed-colored nonwoven or woven supporting fabric web which is strengthened by needling and/or by binders. The supporting fabric forms a backing web and the loose staple fibrous material is needled into this supporting web from the backside of the web within the range or area where the ornamental pattern is to be provided. During the needling process, the supporting web is maintained stationary and immediately after the needling process has been performed, fibers which have not been adhered to the backing web by the needling operation are drawn off by a suction or vacuum. The supporting web is intermittently fed through the needling apparatus backside-up with the needling of the fibers into the web being performed each time the web is stopped. During this operation, the entire surface of the supporting web may be covered with fibers and, if necessary, an additional prestrengthened nonwoven fabric layer may be applied over the entire surface of the supporting web.
The apparatus of the present invention comprises a plurality of needling stations at which there are located needles which are disposed in a particular arrangement to impart a predetermined pattern to fibers which are to be needled into the supporting web. Each of the needle stations may have the needles located thereat arranged in such a manner that each station produces only a designated portion of the ornamental pattern which is to be applied. A feed duct arranged adjacent each needling station on the upstream side thereof delivers fibers onto the intermittently moving web through a discharge port located to extend across the web transversely of its feed direction. A driven roller is located in the vicinity of the discharge port and operates to distribute the delivered fibers upon the web. A suction duct is located downstream of each needling station and as the web passes beyond the needles, loose fibers which have not been properly adhered to the web are drawn off from the backside of the web through an inlet port of the suction duct extending across the web transversely of the feed direction.
In accordance with the invention, a supporting web of the type previously described is thus moved intermittently through the apparatus with its backside facing upwardly and loose staple fiber material of a desired color is applied upon the web and is mechanically joined to the web by needling within the region or area of the ornamentation which is to be produced. Needling is selectively effected at those points where a corresponding color for the desired pattern is to be applied. As a result of the needling operation, the front side of the web which is intended as the visible side of the fabric when it is in use and which is downwardly-facing during the needling operation, has produced thereupon the desired ornamental pattern.
During the patterning process, the intermittently-advancing web is maintained stationary while fibers of a particular color are applied and is subsequently moved an appropriate distance to a succeeding station after the patterning of a certain color is completed.
After loose staple fibrous material of a certain color has been applied to form a particular part of the ornamental pattern, those fibers which have not been joined with the supporting web by the needling operation are drawn off by suction or vacuum immediately downstream of each needling station. It is considered preferably to arrange the needles of the apparatus closely together in order that there may be obtained a precise and adequate connection of the fibers upon the supporting material. A limited number of strokes of the needles is thus sufficient to obtain adequate connection of the fibers with the supporting material. However, the strengthening which thus occurs is not sufficient for proper formation of mechanically strengthened nonwoven fabric since the mechanical fastening which occurs is effected with unavoidable intervals between the individual needles. It has been found, for example, that intervals of 3 mm will occur between individual needles. In view of this, removal of the unneedled staple fibers by suction may be followed under a uniform feed of the supporting web by a process of needling up, down or through the web over its entire surface so that, if necessary, an additional prestrengthened nonwoven fabric may be applied to the supporting web.
If, for example, the staple fibers are needled through following the patterning, it may be of particular advantage to apply an additional prestrengthened nonwoven fabric in order to achieve a backing which is smooth and which imparts an aestehtic appearance to the fabric. This may be accomplished even before the continuous pile needling but after the intermittent patterning is completed. The mechanically prestrengthened nonwoven fabric cover may have a neutral color so that the finished pile rows which are formed appear on the front side of the web as a color mixture of the fibers of the additional cover fabric, on the one hand, and of the patterning color of the applied fibers, on the other hand. The color intensity of the color mixture in the pile rows depends particularly upon the selection of the needles, the depth of puncture, the thickness of the supporting material used and hence of the supporting web and, in the given case, upon the cover web used on the one hand, taken relative to the amount of fibers used for the pattern, on the other hand.
In accordance with another feature of the invention, the needling of additional ornamental regions into the supporting web by utilizing loose staple fiber material of a different color to achieve an additional ornamental section or pattern, and the drawing off by suction of the unneedling staple fiber material, may be repeated a number of times corresponding to the number of colors which are to be used in forming the ornamental pattern. The patterning process may thus be repeated as necessary until the fibrous material is mechanically connected with the supporting web in the various colors which are to appear in the ornamental pattern. This is accomplished until the pattern is thus completed.
It is of course possible to use a single color for the pattern or several colors may be used. Also, the supporting material may be partially covered with the applied fibers or it may be covered therewith over its entire surface area. If, for example, four colors are to be used, four needling units will be required to perform the entire patterning operation. In such a case, the repeat distance may be identical with the respective width of an individual needle board. If the repeat is to be greater, that is if its dimensions are to exceed the width of a needle board, it is possible to utilize two or more patterning units for a particular color and in this way obtain the desired repeat. For example, with four colors and three needling units per color, a total of twelve needling units may be arranged in series. The size of the repeat may thus be determined within wide limits. There will also be a wide available range with regard to the number of colors which may be utilized.
During the patterning operation described above, it is important that the fibers which form the desired pattern are adequately connected with the supporting material at the proper point determined by the pattern of the ornament in order to be able to remove those fibers which are not connected with the supporting material.
After the patterning has been completed in the manner described above, the staple fibers are drawn up, down, or in the case of a nonwoven pile fabric, through in a known manner in a continuous feed.
In a further development of the method according to the present invention, a brushing or shearing operation may be arranged to immediately follow the needling operation whereby removal by suction of loose staple fiber material which has not been properly connected with the supporting web may be facilitated.
It is of particular advantage that the needling which is performed is effected from the backside of the web since this not only facilitates the removal of loose fiber but it also renders unnecessary utilization of a latex coating or layer upon the backside of the fabric. As a result, the combination of needling from the backside and utilization of suction, with or without a brushing or shearing operation, enables formation of the desired ornamental pattern with better accuracy.
The invention is further concerned with a needling machine for carrying out the method according to the invention wherein at least one needle board is associated with the intermittently moving prestrengthened supporting material and which can be moved back and forth for the needling process perpendicularly to the plane of the supporting web.
In the operation of the apparatus of the present invention, the loose staple fiber material is first applied upon the backside of the supporting web at a point prior to passage of the web by the needle board which comprises the particular needle arrangement corresponding to the ornament shape which is desired for the applied fiber. The particular fiber color is thus needled into the supporting web in the shape desired for the particular color involved with the unneedled fiber being subsequently removed after the web has passed from the area of the needle board. In order to facilitate removal of the loose fiber material after needling, a driven brushing or shearing roll may be arranged downstream of the needle board but upstream of the suction duct.
If needling machines or needling units of the aforementioned type are arranged in series, and if a supporting web is moved through each station comprising a needling unit, each machine will produce a particular ornamental pattern. The arrangement of the needles and of the needle board may be such that the differently colored ornaments may adjoin each other directly and complement each other to yield total ornaments of different patterns and colors.
If the required needle arrangement for each needling board is maintained together with the indicated arrangements for the feed duct, the distributor roller, the suction duct and the brushing or shearing roller, conventional needling machines of various types may be utilized together with principal elements of the present invention. Such prior art machines may thus be supplemented with the features of a machine according to the present invention thereby permitting utilization of the method of the invention.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated and described a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a side elevation showing a schematic representation of a machine arranged with a plurality of individual needling units in accordance with the present invention; and
FIG. 2 is a schematic plan view showing a nonwoven fabric upon which there is produced a multicolored ornament during passage of the fabric through the needling machine of the invention.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1, a needling machine is schematically represented which includes three needling units but which may be arranged to include additional needling units (not shown) following the three units which are depicted.
In the arrangement depicted, the driving motor of one needling unit serves to simultaneously drive an adjacent needling unit. A pair of input rolls 1 and 2 operate to introduce into the apparatus a supporting web which is strengthened by needling. Corresponding exit rollers (not shown) may be arranged at the opposite or right hand end of the machine, in order to appropriately receive the finished web, for example, by winding the web upon a drum.
The supporting web which is introduced through the feed rolls 1 and 2 is moved through the apparatus in an intermittent fashion and is supported in the range of each of the needling units or stations by support plates 4 which are provided with holes or oblong slots for passage there through of needles. Located above the supporting plates 4 and arranged at a distance corresponding to the thickness of the moving fabric there are provided vertically adjustable retaining plates 5 which are configured with holes to permit passage therethrough of needles which extend from needle boards 6, 7 and 8. The needle boards 6, 7 and 8 are each located, respectively, at one of the three needling stations depicted in FIG. 1 and they are secured within slides 9 to be vertically movable upwardly or downwardly relative to each of the needling stations. Guides 10 located in the machine frame operate to direct the vertical movement of the needle boards 6, 7 and 8 and eccentric cranks 11 are articulated at their upper ends and are provided to drive the needle boards 6, 7 and 8 through their vertical movement upwardly or downwardly of each needling station. The eccentric cranks 11 are attached to eccentric disks 12 which are rotatably arranged to drive the slides 9, and thus the needle boards 6, 7 and 8, upwardly or downwardly.
The depth of puncture of the needles of each of the needle boards may be varied by adjusting gear (not shown) in a manner which permits displacement of bearing blocks 14 which are arranged to support the eccentric disks 12 within guides 15. The eccentric disks 12 are driven by belts 16 which are operatively associated in pairs with motors 17 to transmit driving power therefrom. Tension rollers 18 engaging the belt 16 insure the necessary belt tension when the vertical position of the bearing blocks 14 is changed. It will be noted that two driving motors 17 are shown and that each of the driving motors 17 is arranged to drive a pair of adjacent units through a pair of belts 16, with the driving motor 17 located at the rightmost end of the drawing being arranged to drive a needling unit which is not shown but which would be located to the right of the arrangement shown in FIG. 1.
Thus it will be seen that each of the needling boards 6,7 and 8 defines a needling station and that as the supporting web 3 is passed to the right, as viewed in FIG. 1, through the apparatus of the invention, a separate needling operation will occur at each of the needling stations defined by each of the needle boards 6, 7 and 8.
Directly adjacent each of the needling units there is provided a feed duct 19 located on the upstream side of each needling station. The feed duct 19 includes at its lowermost end a discharge port which extends across the entire width of the supporting web 3 in a direction transversely of the feed direction of the web 3. Loose staple fiber material preferably of a predetermined desired color, is fed through a duct 21 by means of a blower 20 into the feed duct 19 and through its discharge port from which it is delivered directly upon the upwardly facing surface of the supporting web 3. A driven distributor roller 22 is located in the mouth of the discharge port of the feed duct 19 and extends across the supporting web 3 transversely of its feed direction. The roller 22 is rotatively driven in order to distribute the loose staple fiber material with a certain layer thickness over the upper surface of the supporting web 3.
On the downstream side of the needling station and directly beyond the retaining plate 5, a brushing or shearing roller 23 is arranged to extend across the width of the supporting web 3 transversely of the feed direction thereof. A suction duct 24 is located downstream of the brushing roll 23 with an inlet port extending across the entire width of the supporting web 3 in a direction transversely of the feed direction of the web 3. The inlet port of the suction duct 24 is located above the web 3 adjacent thereto and loose staple fiber material which is not suitably attached to the web 3 by the needling operation is drawn off by suction from the upper surface through the duct 24 by means of the blower 20 which creates a vacuum enabling such loose staple fibers to be passed from the duct 24 to be recycled back into the feed duct 19 so that they may be once again redelivered upon the supporting web 3 for passage through the needling station.
Each of the needle boards 6, 7 and 8 are arranged with a set of needles adapted to produce a particular ornamental shape or configuration in the supporting web 3. For example, and referring more particularly to the supporting web shown in FIG. 2, it may be assumed that the needle board 6 is equipped with needles arranged in such a manner that an ornamental pattern corresponding to the pattern labeled A in FIG. 2 may be produced upon supporting web 3 when it is passed through the needling station defined by the needle board 6. In the operation of the device, the supporting web 3 is stopped so that a section of the web 3 at which the pattern A is to be produced is located and held beneath the needles of the needle board 6. With the web held stationary in this position, the operation of the needle board 6 is performed and the web is subsequently passed to the next succeeding needling station. As it leaves the needling station of the needle board 6, the web 3 will have thereupon a pattern or ornamental outline such as the pattern A.
Thus, for example, assuming that the supporting web 3 consists of fabric made of material which has not been dyed, and assuming that a red ornamental pattern is to be needled into it, red staple fibers would be applied upon the supporting web 3 through the first duct 19 located upstream of the needling board 6 with distribution of the red fibers being effected by the distributor roller 22. With the supporting web 3 being intermittently advanced, as previously described, the needling will be effected by the needles of the needle board 6 with the web 3 held stationary so that the loose red staple fibers located within the range of the needles of needle board 6 will be attached to the web 3 to produce the ornamental pattern A.
Subsequently, supporting web 3 is moved further downstream of the apparatus until the ornamental pattern A is within the range of the needles of needle board 7. As this section of the supporting web 3 passes from beneath the needle board 6, the roller 23 will loosen or raise staple fibers which have not been suitably attached to the supporting web 3 or, if the roller 23 is designed as a brush roll, it will brush up such excess fibers. As the web 3 passes beyond the roller 23, the loose fibers whose disengagement has been promoted by the roller 23 will be drawn off through the suction duct 24 adjoining the needle board 6. The supporting web 3 will thus be devoid of red colored staple fibers except for those which have been suitably adhered to the web 3 to form the ornamental pattern A by the needles of the needle board 6.
As the supporting web 3 moves downstream of the apparatus, the section thereof containing the ornament A will be stopped at an appropriate location beneath the needle board 7 so that the ornamental pattern A may be supplemented by the addition of a further ornamental section or pattern B which may, for example, be of a blue color. The needle board 7 will thus be equipped with needles arranged in a pattern which is designed to produce the ornamental pattern B adjoining the ornamental pattern A. Thus, an overall pattern which is the combination of A and B will be effected. The operation of the apparatus at the needling station defined by the needle board 7 is identical to that of the needling station defined by the needle board 6. Thus, blue staple fibers will be delivered through a feed duct 19 upstream of the needle board 7 and they will be distributed upon the web 3 by a distributor roller 22. Following the needling operation, whereby the ornamental pattern B is effected by the needle board 7, loose fibers will be alleviated by the roller or brush 23 and they will be withdrawn by suction through a duct 24 immediately downstream of the needle board 7.
It will be apparent that a similar process may be performed at each of a plurality of serially arranged needling stations along the length of the apparatus. For example, one additional needling station is shown in FIG. 1 which comprises a needle board 8 whose needles are arranged to produce the ornamental section labeled C in FIG. 2. With the ornamental sections A and B already applied, the needling station defined by the needle board 8 will supplement the ornamental pattern by the addition of the ornamental section C. This ornamental section may be of any desired color and it may, of course, comprise a color different than the colors of sections A and B. It will be apparent that after the production of section C, further ornamental sections, such as for example the ornamental section D, may be produced by additional downstream sections of the needling apparatus. Thus, an overall ornamental pattern comprising the sections A, B, C and D, as depcited in FIG. 2 may be produced. At each needling station, the fibers are delivered by a feed duct 19 and distributed by a distributor roller 22 and loose fibers are withdrawn through a suction duct 24 cooperating with a roller or brush 23. At each phase of the needling operation, the web 3 is stopped with appropriate sections located beneath the needle boards of each of the needling stations so that a desired pattern may be obtained.
The application of ornaments such as the pattern comprised of sections A, B, C and D, produced by needling staple fibers into a supporting web produces a local thickening of the web at the area where the fibers are needled-in. If a uniform fabric thickness is desired in the finished product, additional needling units may be provided with needle boards having a needle arrangement which effect additional inclusion of fibers in regions outside of those regions where the ornamental pattern is produced. For example, referring to FIG. 2, the ornamental pattern comprising the sections A, B, C and D may be supplemented by additional needling operation whereby the fiber of a contrasting color is applied in the areas surrounding each of the ornamental sections. Such additionl needling operations do not serve directly for producing a particular ornamental pattern but rather serve the purpose of filling in intervals between the patterns previously produced.
The aforementioned needling operations are subsequently followed by a conventional or usual needling operation to strengthen the nonwoven fabric by needling up, down or through the web. Such strengthening may be performed by means of known needling machines and this approach is of particular importance with regard to the production of three-dimensional, nonwoven pile fabrics, where a pile needling machine is used for the through-needling and the formation of the pile, respectively.
The needles which are utilized for the needle boards 6, 7 and 8 are of the type which will produce the desired pile layer forming the ornamental pattern of the fabric on the underside of the supporting web 3. That is, the loose fiber which is delivered upon the upper surface of the web 3 will actually be needled so as to form the desired visible pile layer upon the underside of the web 3. Thus, in terms of the finished fabric which is produced, the upper side will be the backside of the fabric and the underside will be the front or visible side. The needled fibers will protrude in loops or tufts from the underside in order to form thereon the pile of the fabric which will be arranged in the manner previously described, to form the desired ornamental pattern.
As a result of applying the loose fiber from the backside of the fabric, removal of loose fiber which has not been adequately needled into the web 3 is greatly facilitated. Since the dense pile will be formed on the underside, the suction duct 24 will operate much more effectively on the backside of the web to remove the loose fiber. Fiber removal will be faciliated to an even greater extent when the shearing or brushing rollers 23 are utilized in conjunction with the suction ducts 24.
As a result of the method of the invention, the ornamental pattern of the pile layer may be formed with greater accuracy. Loose fiber which has not been adequately needled into the supporting web 3 will be more thoroughly removed prior to movement of the web to a next succeeding needle board. Thus, each needle board will needle into the web only fiber which has been delivered upstream thereof, and not fiber intended for needling by a preceding needle board. The integrity of the pattern will be maintained and, particularly where differently colored fibers are to be needled-in by adjacent needle boards, undesired intermingling of colors will be avoided.
As previously discussed, the concepts of the present invention can be practiced by utilizing the various apparatus of the present invention together with known needling machines, for example, of the conventional type depicted in FIG. 1. However, the method according to the present invention may also be applied with other known needling machines. Such machines will require merely the addition of the feed ducts 19 and of the suction ducts 24 with the blowers 20, as well as the arrangment of the distributor rolls 22 and of the brushing rolls 23. However, the specific needling equipment may vary and may be conventional within the context of the present invention.
It will be seen that the method and apparatus of the present invention do not require means for printing ornaments upon a fabric or other additional machines for the production of the ornamental pattern. The pattern can, instead, be combined directly with the needling operations and the production of the patterns performed simultaneously with the needling operations. Only the needle boards will require equipment with needles corresponding to the ornamental patterns to be produced and care must be taken to insure that the intermittent feed of the supporting web is maintained with sufficient accuracy so that individual ornamental patterns which are to complement each other to form the overall pattern desired fit together exactly. Of course, it will be apparent that certain minor inaccuracies are not necessarily unacceptable since a pattern of rather soft coloration is obtained particularly since the underside of the supporting web becomes the visible surface. This is also true when additionl nonwoven fabric is applied and superimposed upon the needled fabric and is needled jointly therewith with the pattern fabric.
The nonwoven fabrics and fibers which may be utilized with the present invention include staple fibers of synthetic material which may, for example, be selected from the group consisting of polyamide, polyacrylic, polyester and polypropylene fibers.
While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.
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Pile fabric is produced by needling in an ornamental pattern a pile layer of loose fibers through the back or nonvisible side of a fabric backing web which is intermittently passed with its back side up through a series of needling stations comprising needles disposed in a particular arrangement to form the fibers into the backing web in a predetermined pattern. A feed duct including a discharge port extending across the fabric web transversely of its feed direction is arranged to deliver fibers onto the back side of the web at a point upstream from the needling station. A suction duct located downstream from the needling station draws loose fibers from the back side of the web through an inlet port which extends across the web transversely of the feed direction. A driven roller located at the discharge port of the feed duct operates to distribute across the web the fibers being delivered thereon and a brush or shearing roller may be arranged downstream of the needling station near the inlet port of the suction duct to draw off loose fibers which have not been suitably needled into the backing web. A pile layer in a predetermined ornamental pattern which is visible from the front or lower side of the web may be formed by sequentially intermittently passing the web through a plurality of needling stations each of which comprises needles disposed to form a section of the overall pattern desired.
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CROSS-REFERENCES TO RELATED APPLICATION
Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The invention relates to dust separating apparatus, particularly but not exclusively to dust separating apparatus for use in vacuum cleaners.
(2) Description of the Related Art
Vacuum cleaners which incorporate dust separating apparatus consisting of two cyclones and a shroud are known. The cyclones are arranged one inside the other with the shroud located between them so that, in use, air first enters the low efficiency cyclone and then passes through the shroud before entering the inner, high efficiency cyclone. In order to ensure that the airflow in each cyclone follows an appropriate helical path, each cyclone has a tangential air inlet consisting of a conduit which approaches the relevant cyclone tangentially and terminates at the cylindrical or conical outer wall of the cyclone. Air flowing along the conduit then passes tangentially into the cyclone and follows the appropriate helical path.
The need for a tangential air inlet to each cyclone, combined with the belief that any irregular protrusions within the outer wall of the cyclone will disturb the airflow, has meant that, until now, all cyclonic dust separation means used in vacuum cleaners have had horizontal air inlets, ie. air inlets arranged perpendicular to the longitudinal axis of the cyclones. The development of a compact cylinder-type vacuum cleaner which utilises cyclonic dust separation apparatus has now created a need for such apparatus having an air inlet which is vertical or parallel to the axes of the cyclones. The provision of such apparatus in a vacuum cleaner would then allow a wand or hose to be attached to the inlet via a swivel coupling pivotable within a generally horizontal plane which then gives greater flexibility and freedom of movement of the wand or hose.
SUMMARY OF THE INVENTION
The invention provides a dust separating apparatus present and a vacuum cleaner. Preferable and advantageous features are set out in the detailed description.
As mentioned above, the invention allows a hose or wand to be coupled to the inlet via a swivel coupling. Also, because the conduit projects into the cyclone, the conduit is rendered easily visible and accessible thus facilitating the removal of blockages of the inlet. The projection of the conduit into the cyclone also means that the cyclone can be increased in length with the result that the cyclone has added capacity to collect separated dirt and dust.
An embodiment of the invention will now be described with reference to the accompanying drawings wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional side view of dust separating apparatus according to the invention; and
FIG. 2 is a perspective side view of the inlet and shroud forming part of the apparatus shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The apparatus 10 shown in the drawings is suitable for use in a vacuum cleaner. The apparatus 10 incorporates a dirty air inlet 12, an outer low efficiency cyclone 14, a shroud 16, an inner high efficiency cyclone 18, a fine dust collector 20 and an exit port 22. The outer cyclone 14, the shroud 16, the inner cyclone 18, the collector 20 and the exit port 22 are all of known design and do not form essential parts of the present invention. Therefore, they will be described only briefly here.
The outer cyclone 14 has an outer wall 14a having an inner surface 14b. A dirt and dust collecting area 14c is located adjacent the lower end of the outer wall 14a.
The inner cyclone 18 consists of a frusto-conical wall 18a having an inner surface 18b and a longitudinal axis 18c. The conical wall 18a terminates in a cone opening 18d which opens into the fine dust collector 20. The fine dust collector 20 is substantially larger in diameter at its outer walls 20a than the cone opening 18d. The outer walls 20a are connected to the frusto-conical wall 18a of the inner cyclone 18 by means of inclined walls 20b. These inclined walls 20b also form the lower boundary of the dust collecting area 14c of the outer cyclone 14.
Positioned between the outer and inner cyclones 14,18 is the shroud 16. The shroud 16 is manufactured separately from the frusto-conical wall 18a of the inner cyclone 18 and connected thereto during manufacture. The shroud 16 has a cylindrical portion 16a which contains a multiplicity of perforations (not shown). Depending from the cylindrical portion 16a is an annular lip 16b comprising a parallel-sided portion having an inclined end surface. The inclined end surface is preferably inclined at an angle of 45° to the longitudinal axis 18c of the inner cyclone 18. Means for allowing passage of air from the interior of the shroud 16 to the interior of the inner cyclone 18 are provided but, for reasons of clarity, are not shown. The air transfer means ensure that air passing from the interior of the shroud 16 to the interior of the inner cyclone 18 enter the upper end of the inner cyclone 18 in a tangential manner.
The inner cyclone 18 is also provided with an exit port 22 which is located substantially centrally of the end of the inner cyclone 18 having the larger diameter. The exit port 22 is conveniently connected to an appropriate clean air exhaust port.
The apparatus shown in FIG. 1 is normally used in the following manner. Dirt-laden air enters the outer cyclone 14 tangentially via an air inlet. The airflow spirals down the inner surface 14b of the outer wall 14a and, whilst the airflow then continues along the airflow path by passing upwardly towards the shroud 16, larger particles of fluff and dirt are collected in the dirt and dust collecting area 14c of the outer cyclone 14. As the airflow passes towards the shroud 16, the lip 16b discourages any blocking of the perforations of the shroud 16. The airflow passes through the perforations in the cylindrical portion 16a of the shroud 16 and then passes from the interior of the shroud 16 to the upper end of the inner cyclone 18. Because of the tangential entry into the inner cyclone 18, the airflow spirals down the inner surface 18b of the frusto-conical wall 18a of the inner cyclone 18. Most of the air subsequently moves towards the axis 18c of the inner cyclone 18 and then exits via the exit port 22. However, dirt and dust particles previously entrained within the airflow spiral downwards towards the cone opening 18d and emerge into the collector 20 at very high speeds. The dirt and dust particles are flung towards the side walls 20a of the collector 20 and collect at the bottom of the collector 20. The remaining air passes back through the cone opening 18dinto the inner cyclone 18 and subsequently exits the apparatus via the exit port 22.
In all prior art apparatus, the air inlet 12 has consisted of a conduit arranged substantially horizontally, ie. perpendicular to the longitudinal axis 18c of the inner cyclone 18, and which terminates at the outer wall 14a of the outer cyclone 14. This has previously effected a tangential entry into the outer cyclone 14 without causing any unnecessary disturbance to the airflow within the outer cyclone 14. According to the present invention however, the inlet 12 consists of a conduit 12a arranged substantially vertically or parallel to the axis 18c of the inner cyclone 18. The conduit 12a passes into the interior of the outer cyclone 14 between the outer wall 14a and the cylindrical portion 16a of the shroud 16. The conduit 12a also comprises a right angle bend 12b which causes the incoming airflow to exit the conduit 12a in a manner which is tangential to the outer wall 14a. It has been found that this arrangement does not unduly disturb the airflow within the outer cyclone 14. The distance between the outer wall 14a of the outer cyclone 14 and the cylindrical portion 16a of the shroud 16 is preferably between 15 mm and 30 mm and the efficiency of the apparatus is particularly high if this distance is substantially 20 mm.
It is highly advantageous to be able to-introduce the airflow into the outer cyclone from above the outer cyclone 14. In particular, this allows a hose 12c to be attached to the conduit 12a by means of a swivel coupling. When the apparatus 10 is utilised in a cylinder-type vacuum cleaner, this allows the hose 12c, to the end of which a cleaning tool is attached, to be swivelled through 360° about the axis 12d of the conduit 12a, ie. within a substantially horizontal plane. This in turn allows greater flexibility and maneouverability of the machine than would be achievable without the swivel coupling.
It will be appreciated that it is not necessary to attach the hose 12c to the conduit 12a in a plane which is perpendicular to the axis 12d of the conduit. An inclined connection could be provided which would allow the hose 12c to swivel in a plane which is inclined to the axis 12d. This is particularly useful when the apparatus 10 is incorporated into a vacuum cleaner in an inclined manner, ie. the axis 18c is inclined to the vertical. This, in turn, means that the axis 12d will be inclined to the vertical but the swivel coupling between the hose 12c and the conduit 12a can be such that the hose 12c can swivel in a substantially horizontal plane or, indeed, any other convenient plane.
It will be apparent to any reader skilled in the art that the invention is not limited to the specific embodiment described above. Various modifications and alterations will fall within the scope of the invention.
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The invention provides dust separating apparatus (10) including a cyclone (14) having an outer wall (14a) and an air inlet (12), a shroud (16) and an airflow path, the airflow path being arranged so as to direct an airflow flowing, in use, in the dust separating apparatus into the cyclone (14) via the air inlet (12) and out of the cyclone through the shroud (16). The air inlet (12) of the cyclone (14) is formed by a conduit (12a) projecting into the cyclone (14) between the outer wall (14a) and the shroud (16). This allows a swivel coupling to be attached to the air inlet (12) providing greater flexibility and maneuverability of the dust separating apparatus (10).
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CROSS-REFERENCE TO RELATED APPLICATION(S) AND CLAIM OF PRIORITY
[0001] The present application claims the benefit under 35 U.S.C. section 119(a) of Japanese Patent Application filed in the Japan Patent Office on Jul. 4, 2007 and assigned serial number 2007 - 176029 , the disclosure of which is incorporated herein by reference.
FIELD OF INVENTION
[0002] This invention relates to a friction material for use as a disc brake pad and a brake lining for automobiles.
BACKGROUND OF THE INVENTION
[0003] A friction material mounted on a rear brake of an automobile is often used for both service brakes and parking brakes. The required performance for the friction material to be used in the service brake is different from the required performance for the friction material to be used in the parking brake. The service brake needs such as excellent and stable brake effectiveness, good fading resistance and good wearing resistance, high mechanical strength, and low incidence of noise. The parking brake needs high static coefficient of friction and a small amount of thermal expansion and contraction so as to securely hold an automobile on a slope.
[0004] For the friction material with high static coefficient of friction when using the parking brake, the patent document 1 (Japanese Unexamined Patent Publication No. 9-67449) discloses a friction material for a parking brake made by entirely or partially coating a rubber or solution of rubber compounds on a friction surface of the friction material and by heating and vulcanizing the same, and the patent document 2 (Japanese Unexamined Patent Publication No. 9-67450) discloses a hybrid friction material for a parking brake made by forming as placing a high dumping raw material plate made of rubber or rubber compounds, when pre-forming the friction material, on agitation compounds for the friction material manufacturing to be embedded therein to coexist surfaces with different characteristics on the friction surface. Also, the patent document 3 (Japanese Unexamined Patent Publication No. 2005-233283) discloses a friction material for a parking brake which uses 25-40 volume % of a hard inorganic particle with an average particle diameter of between 200 and 400 μm and Mohs hardness of 7-9 as the abrasive.
[0005] However, these friction materials are used solely for parking brakes, and they cannot satisfy the required performance when used for service brakes. Even if a material with a high dumping capacity is applied on the friction surface of the friction material, just like the patent documents 1 and 2, effective performance does not last because the high dumping material becomes worn out after continuous use of the same for the service brake, and the friction material includes abrasive largely just like the patent document 3 and thus causes a problem of increasing the abrasiveness against a mating member (such as a disc brake rotor and a brake drum) when the service brake is applied.
[0006] On the other hand, study regarding the friction material used to secure both service brake and parking brake performances has been done, and the patent document 4 (Japanese Unexamined Patent Publication No. 2002-275452) discloses a friction material that offers superior brake effectiveness for the service brake and at the parking brake operation restricts the noise generation due to oscillation of a vehicle body when the driver gets off the vehicle after applying the parking brake. This friction material includes 1-15 volume % of an inorganic fiber with Mohs hardness of lower than 4.5 and 1-15 volume % of cashew dust. However, no study has ever been conducted as to the improvement of the static coefficient of friction during the parking brake and restriction of the thermal expansion and contraction of the friction material.
[0007] Patent Documents
[Patent Document 1] Japanese Unexamined Patent Publication No. 9-67449. [Patent Document 2] Japanese Unexamined Patent Publication No. 9-67450. [Patent Document 3] Japanese Unexamined Patent Publication No. 2005-233283. [Patent Document 4] Japanese Unexamined Patent Publication No. 2002-275452.
SUMMARY OF THE INVENTION
[0012] This invention was made in consideration of the above-situations and provides a friction material with an excellent balance for both service brake and parking brake usages which satisfies the required performance for the service brake and maintains the high static coefficient of friction during parking brake operation; and restricts the thermal expansion or contraction of the friction material to restrain reduction of the pressing force against the mating member.
[0013] The inventors of the present application conducted a thorough study to achieve the above-described objects and then found that eliminating a factor of reducing the brake force is more effective than positively increasing the static coefficient of friction during the parking brake operation for the friction material generally used for both service brake and parking brake and that (1) the pressing force against the mating member (e.g., disc brake rotor or brake drum) is reduced by contracting the friction material by naturally cooling the same when the friction material, which is expanded due to the frictional heating during the service brake operation, is used for the parking brake, and (2) graphite generally applied as the solid lubricant for the friction material reduces the static friction coefficient when a high humidity atmosphere exists, such as during the night time when the parking brake is frequently used.
[0014] <1> This invention discloses a friction material comprising a fibrous base material, a friction modifier, and a binder, wherein said friction modifier includes 5-20 volume % of cashew dust, 10-25 volume % of a rubber composition, and 2-5 volume % of a solid lubricant, a total volume of said cashew dust and said rubber composition is less than 30 volume %, and said friction modifier is without graphite.
[0015] <2> This invention also discloses the friction material according to <1>, wherein the cashew dust is manufactured using furfural as a curing agent
[0016] <3> This invention also discloses the friction material according to <1> and <2> wherein a part of the rubber composition is a vulcanized acrylic rubber powder, and the friction material includes at least 5 volume % or more of a vulcanized acrylic rubber powder as the rubber composition
[0017] <4> This invention also discloses the friction material according to <1>-<4>, wherein the solid lubricant is molybdenum disulfide.
[0018] This invention can provide a friction material that:
(1) gives a superior braking effect, good fading and wearing resistance, high mechanical strength, and low incidence of noise when used as a service brake; (2) can maintain a high static friction coefficient and at the same time minimizes and reduces the pressing force required to brake by restricting the thermal expansion and contraction of the friction material against the surface of the mating member and also securely keeps the vehicle on the slope when used as a parking brake, and (3) can be used as both service brake and parking brake.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The above and other objects of the present invention will become readily apparent by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:
[0023] FIG. 1 is a table showing evaluation results of embodiments 1-8 and comparative examples 1-4;
[0024] FIG. 2 shows the evaluation method and standards; and
[0025] FIG. 3 shows the evaluation method for the static coefficient of friction during parking brake operation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0026] The friction material of the present invention is prepared by forming a friction material granulation which is comprised of a fibrous base material, a friction modifier, and a binder and then curing the same thereafter. Here, in the friction material of the present invention, the friction modifier is characterized to include cashew dust and rubber composition but does not include graphite.
[0027] An inorganic fiber and organic fiber without asbestos, which is generally used for the friction material, may be used as the above-addressed fibrous base material. Examples of the inorganic fibers are a steel fiber, stainless fiber, copper fiber, brass fiber, bronze fiber, aluminum fiber, potassium titanate fiber, glass fiber, rockwool, wollastonite, and more, and examples of the organic fibers are aramid fiber, carbon fiber, polyimide fiber, cellulose fiber, acrylic fiber, and more. Among these fibrous base materials they can be used alone or as a combination of two or more types. An amount of overall fibrous base materials included in the friction material may be adjusted within a range that does not lose the advantages of the present invention.
[0028] The friction modifier is added to adjust the coefficient of friction, suppress the noise, and to prevent rust and has such as an inorganic filler, an organic filler, and a solid lubricant as appropriate, where the organic filler may be such as cashew dust and rubber composition. The cashew dust is added to stabilize the coefficient of friction during the service brake operation. If the friction material frictionally engages the surface of the mating member during the service brake operation, the cashew dust in the friction material melts due to the frictional heating, and a thin organic film uniformly covers the surface of the mating member. Covering the surface with the film stabilizes the coefficient of the friction material. However, the cashew dust expands and contracts in great extent due to the heat, which causes the friction material to thermally expand and contract. Here, adding the rubber composition helps to restrict the thermal expansion of the friction material. The rubber composition, functioning as an elastic member, contracts the same, or in equal proportion to, (equally) the amount of expansion of the cashew dust due to the frictional heating so that the thermal expansion of the friction material itself is restricted.
[0029] Also, the addition of the rubber composition increases the elasticity of the friction material, and therefore the amount of contraction of the friction material increases when pressing the friction material against the mating member. If the amount of contraction of the rubber composition is equal to or more than the amount of expansion of the friction material, then when the friction material is contracted by cooling, no radical reduction of the pressing force can be seen, thereby restraining a decrease of the pressing force against the mating member.
[0030] Also, the solid lubricant is used to secure the wearing resistance during the service brake operation. Adding a solid lubricant that is something other than graphite to the friction material can effectively restrict the reduction of the static coefficient of friction during parking brake operation. This is true because graphite is characterized by the fact that the coefficient of friction thereof becomes lower in humid air than in dry air.
[0031] The amount of cashew dust is preferably 5-20 volume %. If the amount of cashew dust is less than 5 volume %, it is difficult for the cashew dust film to form on the mating member. If the cashew dust film is not formed on the mating member, iron composition of the mating member is transferred to stick on the friction material, which causes an iron to iron grinding type friction to increase the abrasiveness against the mating member and to damage the wearing resistance. Also, if the amount of cashew dust is more than 20 volume %, the cashew dust film formed on the mating member becomes too thick, which tends to reduce the coefficient of friction during the service brake operation.
[0032] The cashew dust is made by curing cashew nut shell liquid, or polymer of the same, by curing agents such as furfural, formaldehyde (as one type of an aldehyde), or hexamethylenetetramine, then cooling and crushing. In this invention, the cashew dust, which is obtained by using such as formaldehyde and hexamine as a curing agent, and the cashew dust, which is obtained as using furfural as a curing agent, can be used independently or in combination; however, the cashew dust, which is obtained as using the furfural as the curing agent is preferable. Comparing the cashew dust which is obtained using the furfural as the curing agent, and the cashew dust which is obtained using such as the formaldehyde and hexamine as the curing agent, the former cashew dust, shows high heat resistance and can restrict the thermal expansion.
[0033] The amount of rubber composition is preferably 10-25 volume %. If the amount of the rubber composition is less than 10 volume %, the thermal expansion of the friction material itself becomes larger and the elasticity of the friction material itself becomes smaller, and therefore the static coefficient of friction, during the parking brake operation, tends to decrease. Also, the vibration damping effect becomes less effective, and a squealing noise tends to be caused during the service brake operation. If the amount of the rubber composition is more than 25 volume %, the wearing resistance is decreased.
[0034] The rubber composition may be any one of or any combination of natural rubber, polyisoprene rubber (IR), acrylonitrile butadiene rubber (NBR), styrene butadiene rubber (SBR), butadiene rubber (BR), chloroprene rubber (CR), butyl rubber (IIR), ethylene propylene rubber (EPM or EPDM), urethane rubber, silicone rubber, fluoro rubber, powder of vulcanized rubber or unvulcanized rubber of acrylic rubber, and crushed powder of tire tread rubber or wiper rubber or window strip rubber. Also, as a part of the rubber composition, vulcanized acrylic rubber powder with high heat resistance is preferably included at 5 volume % or more relative to the total amount of friction material.
[0035] The amount of the cashew dust and the rubber composition combined is preferably 30 volume % in total or less. If the total amount of the cashew dust and the rubber composition is more than 30 volume %, the amount of organic substance involved in the friction material becomes too much, which worsens the fading resistance (tends to fading).
[0036] Next, the solid lubricant can be one of or a combination of metallic sulfide, without graphite, such as molybdenum disulfide, stannic sulfide, and tungsten sulfide; however, the molybdenum disulfide, which is especially not likely to be affected by humidity, is preferably used independently. The amount of the solid lubricant relative to the entire amount of the friction material is preferably 2-5 volume %. If the amount of the solid lubricant is less than 2 volume %, lubrication of the friction material agency is insufficient, which damages the wearing resistance during the service brake operation. Also, if the amount of solid lubricant is more than 5 volume %, the lubrication agency becomes too much, which reduces the coefficient of friction during the service brake operation, and therefore sufficient brake effectiveness cannot be obtained.
[0037] An inorganic filler may be zirconium silicate, zirconium oxide, magnesium oxide, silicon carbide, silicon dioxide, aluminum oxide, barium sulfate, calcium carbonate, calcium hydroxide, mica, vermiculite, triiron tetroxide, a metal powder such as steel, stainless, copper, brass, bronze, aluminum, tin, and zinc. The above-listed examples of metal powders can be used alone or in combination of two or more types.
[0038] A binder that can generally be provided for the friction material can be used. For example, one of or a combination of two or more of such as phenol resin, acrylic rubber denatured phenol resin, NBR denatured phenol resin, phenol alkyl resin, melamine resin, epoxy resin, and benzoxazine resin may be used. The amount of binder relative to the entire amount of the friction material is preferably 10-30 volume %.
[0039] The manufacturing method of the friction material of the present invention is to mix the above-identified compositions evenly using mixers such as a Henschel mixer, a Loedige mixer, an Eirich mixer, to pre-mold in a mold, and to form the molded product by forming the pre-molded product at 140-180° C., 20-50 MPa for 5-15 minutes. Next, the obtained molded product is heat-treated (postcured) at 140-250° C. for 2-48 hours and then is spray-painted, baked, and grinded on the surface as necessary to achieve a final product. When manufacturing a disc brake pad, the disc brake pad is manufactured by placing the pre-molded product on a steel or aluminum plate which is cleaned, surface-treated, and adhesive-coated in advance, and in this situation, molding by the mold for molding, heat-treating, painting, baking, and grinding.
Embodiments
[0040] Embodiments and comparative examples are shown in the following sections to explain the present invention concretely, but the present invention is not limited to the following embodiments.
[0041] The composition of the friction material as shown in FIG. 1 is mixed with the Loedige mixer for 5 minutes and is pressed in the metal mold for molding at 10 MPa for 1 minute so as to pre-form. The pre-molded product is mounted on the iron plate which is cleaned, surface-treated, and adhesive-coated in advance, and in this situation, molding by the mold for molding at the molding temperature of 150° C., the molding pressure of 40 MPa for 10 minutes, heat-treated (postcured) at 200° C. for 5 hours, and grinded to manufacture the friction material (disc brake pad for passenger cars) (as appears in the embodiments 1-8 and the comparative examples 1-4). The friction material is evaluated with respect to the dynamic coefficient of friction during the service brake operation, the static coefficient of friction during the parking brake operation, the wearing resistance, and the fading resistance. FIG. 1 shows the evaluation results; FIG. 2 shows the evaluation method and standards; and FIG. 3 shows the evaluation method for the static coefficient of friction during parking brake operation.
[0042] While the embodiments of the present invention disclosed herein are presently considered to be preferred embodiments, various changes and modifications can be made without departing from the spirit and scope of the present invention. The scope of the invention is indicated in the appended claims, and all changes that come within the meaning and range of equivalents are intended to be embraced therein.
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To provide a friction material with an excellent balance for both service brake and parking brake usage that satisfies the required performance for the service brake and improves the static coefficient of friction for the parking brake. The friction material comprising a fibrous base material, a friction modifier, and a binder, wherein said friction modifier comprises 2-20 volume % of cashew dust, 10-25 volume % of a rubber composition, and 2-5 volume % of a solid lubricant, a total volume of the cashew dust and the rubber composition is 30 volume % or less, and said friction modifier does not use graphite because it can cause the reduction of the coefficient of friction during the parking brake operation.
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BACKGROUND OF THE INVENTION
The invention relates generally to an acoustic detection system, and, more particularly, to a system which is sensitive to sounds outside the frequency range of human hearing to enable a user to enhance his hearing capability.
It is often required in police surveillance and military operations to passively detect the movement of personnel or machinery at extended distances. In many instances, vision is obscured due to darkness, low visibility, obstacles, or dense vegetation. Reception of sounds produced by personnel and machinery may thus be the only method of detecting their presence or movement. However, reception of sound waves solely in frequencies audible to human beings may not provide adequate detection capability.
Sounds outside the frequency range of human beings may, however, exhibit significantly different propagation characteristics. For example, ultrasonic (higher than audible) sound waves produced by movement of personnel, whispering, the impact of metal parts, and sharp explosions, such as from firearms, are more directional than audible sound waves. Infrasonic (lower than audible) sound waves produced by heavy machinery, large vehicles, and helicopter blade chop, on the other hand, may propagate over greater distances. It is therefore desirable to provide the capability for detection, identification, and classification of noise sources for sounds such as those described above in the ultrasonic and infrasonic ranges. Similar requirements also exist in many fields of scientific research, where the events of interest include animal and insect sounds produced in the ultrasonic range and meteorological and seismic events which produce sounds in the infrasonic range.
Events of interest may well produce a variety of sounds over a wide range of frequencies extending from below the lower frequency limit of human hearing to well above the upper frequency range thereof. Initial indication of events of interest may occur in one frequency range, whereas sounds confirming the existence of such activities may be produced in other ranges. It is therefore desirable to provide acoustic detection apparatus which can detect sound waves over a wide range of frequencies both inside and outside the frequency range of human hearing. Equipment which can detect ultrasonic or infrasonic waves has up to this time been large, heavy, and expensive, and was thus more suited to the laboratory than to the field. Accordingly, it is an objective of the present invention to provide acoustic detection apparatus which is low in cost, rugged, and light in weight so as to be suitable for portable operation in the field
SUMMARY OF THE INVENTION
In accordance with the principles of the present invention, there is provided a method for passive acoustic detection, and related apparatus responsive to sound waves outside the range of human hearing which is rugged and lightweight, as well as lower in cost than prior art apparatus. The apparatus includes transducer means for receiving vibratory signals outside the range of human hearing which are generated by events to be detected and for generating electrical signals representative of the received vibratory signals. The apparatus also includes frequency converter means connected to the transducer means for generating signals perceptible to human beings in response to the generated electrical signals.
The transducer comprises a microphone responsive to sound waves having frequencies ranging from infrasonic to ultrasonic. The output signal of the microphone is amplified and supplied in parallel to an infrasonic channel, a sonic channel, and an ultrasonic channel.
The infrasonic channel includes a low-pass filter which has a cut-off frequency somewhat above the lower frequency limit of human hearing and which is connected between the microphone element output and a frequency converter. The frequency converter includes an oscillator and mixer which produces, by the frequency hetereodyning process, an output frequency within the range of human hearing which is equal to the sum and difference of the output signal frequencies of the low-pass filter and the oscillator.
The sonic channel includes a band pass filter having a lower cut-off frequency approximately equal to the cut-off frequency of the low-pass filter and an upper cut-off frequency approximately equal to the upper frequency limit of human hearing.
The ultrasonic channel includes a high-pass filter connected between the microphone output and a second frequency converter including a second oscillator and a second mixer. The output of the second frequency converter is a signal having frequencies within the range of human hearing equal to the difference between the output signal frequencies of the high-pass filter and the second oscillator. The output signals of any or all of the infrasonic, sonic, and ultrasonic channels are selectively passed through a channel selector and mixer, and an appropriate amplifier to an output transducer, such as a headphone. The system thus provides the ability to detect and analyze sounds outside the range of human hearing by converting them to sounds within the range of human hearing. The result is low cost, rugged, lightweight apparatus well suited for use in the field.
The accompanying drawings, which are incorporated in, and constitute a part of this specification, illustrate one embodiment of the invention, and together with the description serve to explain the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of passive acoustic detection apparatus which is preferred embodiment of the invention;
FIGS. 2A and 2B are front elevational views and side sectional views, respectively, of a transducer of the apparatus shown in FIG. 1;
FIG. 3 is an electrical schematic diagram of the channel selector and audio mixer shown in FIG. 1;
FIG. 4 is an electrical schematic diagram of the audio amplifier and volume control shown in FIG. 1; and
FIG. 5 is an electrical schematic diagram of the power supply of the apparatus of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings in which like reference characters refer to corresponding elements, FIG. 1 shows a block diagram of an acoustic detection system 10 which is a preferred embodiment of the present invention. The invention includes transducer means for receiving vibratory signals outside the range of human hearing which are generated by events to be detected and for generating electrical signals representative of the received sound waves. In the preferred embodiment, the transducer means is responsive to airborne sound waves and comprises includes a microphone transducer and preamplifier 12 and microphone buffer 16 as shown in FIG. 1.
The microphone transducer and preamplifier 12 in the preferred embodiment comprises a pair of parallel-connected electret microphone elements which may be, for example, type BT-1759 electret microphone elements obtainable in commercial quantities from the Knowles Corporation. The preamplifier is of conventional construction and may include a two-stage preamplifier circuit using a pair of NE5534 operational amplifiers obtainable in commercial quantities from the Motorola Corporation. Specific methods of constructing such preamplifiers are described in the IC Op Amp Cookbook, by Walter G. Jung published by the Howard Sams Corporation. In a preferred embodiment, the preamplifier provides approximately 65 dB of gain.
Although the transducer means of the preferred embodiment is responsive to airborne sound waves, the invention is not so limited. In alternative embodiments, microphone transducer and preamplifier 12 may comprise a hydrophone responsive to sound waves transmitted through liquids such as water, or seismic sensors responsive to vibrations transmitted through the earth. Furthermore, such hydrophones and sensors may be present either signly or in combination with each other or with microphone elements.
The output of the microphone transducer and amplifier 12 is passed through a ferrite bead 14 to reduce parasitic oscillations and increase stability of the transducer and preamplifier 12, and is connected to the microphone buffer 16. The preferred embodiment comprises a trio of parallel-connected unity gain operational amplifiers which may be constructed using type MC34002 dual operational amplifiers manufactured by the Motorola Corporation.
The invention also includes converter means connected to the transducer means for generating signals perceptible to human beings in response to the electrical signals generated by the transducer means. As embodied herein, the converter means includes an ultrasonic channel 22 connected to the output of microphone buffer 16, a channel selector and audio mixer 42, an audio amplifier and volume control 44, and an earphone 48. Also connected to microphone buffer 16 is an infrasonic channel 18 and a sonic channel 20.
Infrasonic channel 18 includes a filter 24 which in the preferred embodiment is an 8-pole Butterworth low-pass filter having an upper cut-off frequency of 200 Hz. The filter 24 may be constructed using a Motorola type MC34004 quad operational amplifier as described in the article "RC Filter Design By The Numbers" by Russell Kincaid, published in the October 1968 issue of Electronic Engineer magazine, the disclosure of which is hereby expressly incorporated by reference. The output of filter 24 is connected to a mixer 26, which is also supplied with the output signal from an oscillator 28. Mixer 26 processes the output signals of filter 24 and oscillator 28 through a frequency heterodyning process to produce an output signal having a frequency equal to the sum and difference of the output signal frequencies of filter 24 and oscillator 28. In a preferred embodiment, oscillator 28 has an operating frequency of 1000 Hz and employs a type XR-2206 integrated circuit oscillator obtainable in commercial quantities from the Exar Corporation.
The output of mixer 26 is connected to a frequency multiplier circuit which in the preferred embodiment constitutes a frequency doubler 29 producing an output signal having a frequency of twice that of the output signal of mixer 26. In a preferred embodiment, mixer 26 and frequency doubler 29 each include a type MC1496 balanced modulator-demodulator obtainable in commercial quantities from the Motorola Corporation. The specific electrical configuration of mixer 26 and doubler 29 are well-known to those skilled in the art and are described in detail in Motorola Linear Integrated Circuits, a data book published in 1979 by the Motorola Corporation.
The output signals supplied by microphone buffer 16 emerge from filter 24 ranging in frequency from DC (0 Hz) to 200 Hz. These signals are processed by mixer 26 such that they range in frequency from 800 Hz to 1200 Hz and are supplied as input to frequency doubler 29. The output of frequency doubler 29 thus constitutes a signal having frequencies ranging from 1600 Hz to 2400 Hz. This output signal is passed through a notch filter 30 having a rejection frequency of 2000 Hz to eliminate bleed-through of signals from oscillator 28. The specific construction of notch filter 30 is well-known to those skilled in the art and is described in detail in the aforementioned IC Op Amp Cookbook.
It can thus be appreciated that infrasonic channel 18 converts signals having frequencies below the range of human hearing to signals having frequencies well within the range of human hearing.
The output of microphone buffer 16 is also supplied to sonic channel 20, which includes a bandpass filter 32 having upper and lower cut-off frequencies of 200 Hz and 15 KHz, respectively. Filter 32 in the preferred embodiment is a 3 db ripple 8-pole Chebychev bandpass filter having 4 poles of roll-off for each edge of the filter. Filter 32 may also be constructed using a Motorola type MC 34004 quad operational amplifier using principles well-known to those skilled in the art as described in the above-identified article by Russell Kincaid.
Ultrasonic channel 22 includes a bandpass filter 34 having upper and lower cut-off frequencies of 15 KHz and 30 KHz, respectively. Filter 34 in the preferred embodiment is identical to filter 32 with the exception of the cut-off frequencies. The output of filter 34 is connected to a mixer 36, which is also connected to the output of an oscillator 38 having a frequency of 15 KHz. Mixer 36 combines the outputs of filter 34 and oscillator 38 in a frequency heterodyning process to provide an output signal having frequencies equal to the sum and difference between the output frequencies of filter 34 and oscillator 38. The output signal of mixer 36 thus has a frequency ranging from 0 to 15 KHz. Oscillator 38 is identical to oscillator 28, with the exception of the operating frequency. Mixer 36 is identical to mixer 26 and can thus be constructed using a type MC 1496 balanced modulator-demodulator integrated circuit device connected according to information contained in the above-mentioned Motorola data book.
The output of mixer 36 is supplied to a low pass filter 39 having a cut-off frequency of 15 KHz, the output of which is passed through a notch filter 40 having a rejection frequency of 15 KHz. Filter 39 is a 3 dB ripple 4 pole Chebychev filter designed according to well-known principles described in the above-identified article by Kincaid, and filter 40 is designed according to principles described in the aforementioned IC Op Amp Cookbook. Filters 39 and 40 ensure that the output of ultrasonic channel 22 is free from noise signals having frequencies of 15 KHz and above. Ultrasonic channel 22 thus converts signals having frequencies above the range of human hearing to frequencies substantially within the range of human hearing.
The output signals from infrasonic channel 18, sonic channel 20, and ultrasonic channel 22 are each supplied to channel selector and audio mixer 42. These three output signals may thus be selected and combined in any desired combination and supplied to audio amplifier and volume control 44. The output of audio amplifier and volume control 44 is passed through a 100 mH inductor 46 and supplied to an output transducer which in the preferred embodiment comprises earphone 48. Earphone 48 may be a conventional in-the-ear device having an input impedance of, for example, 4-100 ohms. Inductor 46 is provided to increase stability of audio amplifier and volume control 44 when operated under high gain conditions.
Microphone transducer and preamp 12 may include a microphone and reflector assembly 50 shown in greater detail in FIGS. 2A and 2B. Assembly 50 is mounted in a box 52 of any suitable material such as aluminum or polystyrene. In a preferred embodiment, box 52 has height, width and depth dimensions of approximately 3 inches, 3 inches and 11/2 inches, respectively. A parabolic reflector 54 of material such as polystyrene is mounted in the box 52. Reflector 54 has a diameter of approximately 21/2 inches and a depth of approximately of 11/2 inches. First and second directional microphone elements 56 and 58 are positioned as shown in FIGS. 2A and 2B. Element 56 is mounted on the reflecting surface of reflector 54 at the center thereof and is mounted with its direction of maximum sensitivity facing to the right as seen in FIG. 2B. Element 58 is mounted in the center of reflector 54 by struts 59, and is offset from the reflecting surface thereof by a distance which in the preferred embodiment is approximately 0.445 inches, with its direction of maximum sensitivity facing to the left as seen in FIG. 2B. It has been determined that placement of microphone elements in this manner is particularly effective in obtaining a flat frequency response from below the lower frequency limit of human hearing to well above the upper frequency limit of human hearing. The outputs of microphone elements 56 and 58 are connected parallel in a conventional manner to a preamplifier as described above.
An electrical schematic diagram of channel selector and audio mixer 42 is shown in FIG. 3. As can be seen therein, the output signals of filters 30, 32, and 40 from channels 18, 20, and 22, respectively, are connected over lines 30a, 32a, and 40a to analog bilateral electronic switches 60, 62, and 64, respectively. Each of the switches 60, 62 and 64 includes an input terminal connected to filters 30, 32, 34, respectively, an output terminal connected to one end of separate dropping resistors 66, and a control terminal 68. Control terminals 68 are each connected to the output terminal of inverters 70. Separate pull-up resistors 72 are connected between the input of each inverter 70 and the positive terminal of a power supply. The input of each inverter 70 is also connected through a switch 74 to the negative terminal of a power supply. Switches 60, 62, and 64 are of conventional construction and may be type 4016 CMOS switches available in commercial quantities from Motorola. Similarly, inverters 70 are of conventional construction and may be type 4049 CMOS inverters also obtainable from Motorola.
Operation of any of the switches 74 to connect the associated inverter input terminal to the negative power supply is operative to provide a positive signal to input terminal 68 of the respective switches 60, 62, and 64, thus establishing a low impedance path between the input and output terminals of the associated switch. Signals from channels 18, 20, and 22 are supplied in parallel over dropping resistors 66 to the input of an operational amplifier 76, acting as a summing, or mixing circuit, through the action of feedback resistor 78. Operational amplifier 76 may be, for example, one half of a type MC 34002 dual operational amplifier obtainable from Motorola.
The construction of channel selector and audio mixer 42 is provided to ensure superior reliability in harsh environments commonly encountered under field conditions. Specifically, switches 60, 62, and 64 are sensitive to non-nominal voltages applied to input terminals 68. Thus, direct connection of a power supply terminal through switch contacts subject to corrosion and degradation could result in unreliable operation. On the other hand, inverters 70 are very tolerant of a wide range of input voltages and are thus not susceptible to improper operation due to poor condition of the contacts of switches 74. Accordingly, the construction shown in FIG. 3 provides superior performance under field conditions.
FIG. 4 is an electrical schematic diagram of audio amplifier and volume control 44. Output signals from channel selector and audio mixer 42 are provided through a system gain potentiometer 80 to one input of an operational amplifier 82 functioning as a voltage controlled amplifier. Operational amplifier 82 may be, for example, one half of a type MC 34002 dual operational amplifier available for Motorola. The other input of operational amplifier 82 is connected to the drain terminal of a field effect transistor 84, the source terminal of which is grounded. Field effect transistor 84 is operated over its linear range and functions as a variable resistor connected between an input of operational amplifier 82 and ground. The voltage supplied to the gate of field effect transistor 84 is set by a capacitor 86. Capacitor 86 is in turn charged or discharged through high value resistors 88, 90 and analog switches 92, 94 which serve to selectively connector capacitor 86 to either the positive power supply terminal or ground. Switches 92 and 94 are in turn controlled by inverters 96 and 98, the inputs of which are controlled by push button switches 100 and 102, respectively.
Operation of which 102 places the input of inverter 98 at a negative voltage potential, thus causing activation of analog switch 94 which permits capacitor 86 to slowly discharge through resistor 90 to ground. This in turn causes the impedance of field effect transistor 84 to slowly decrease, thus causing the output of preamplifier 82 to slowly increase.
In a similar manner, operation of switch 100 will, through the action of inverter 96, activate switch 92 and cause capacitor 86 to slowly charge to a value approaching that of the positive power supply terminal. This in turn increases the impedance of field effect transistor 84 to decrease the output of preamplifier 82 and lower the volume of signals supplied to earphone 48.
An analog switch 104 is connected between capacitor 86 and the positive power supply terminal. Switch 104, in conjunction with a capacitor 106 and a resistor 108, insures that when the system 10 is first energized the volume from earphone 48 will be low, to avoid initial discomfort to the user. As capacitor 106 charges, switch 104 will open and volume can be set in the manner described above.
The output of preamplifier 82 is connected through a coupling capacitor 83 and resistor 107 to an output amplifier 103 which is of conventional construction and may include, for example, a type LM 386 integrated circuit audio output driver obtainable from the National Semiconductor Corporation. The output of amplifier 103 is connected through a coupling capacitor 109 and inductor 46 to earphone 48.
Power for the system 10 may be supplied by a battery pack providing appropriate voltages. In the preferred embodiment, eight 1.5 volt dry cell batteries 110 are connected to form a plus and minus 6 volt power supply as shown in FIG. 5. A pair of electrolytic capacitors 112 and a pair of disc capacitors 114 are connected across the power supply terminals as shown in FIG. 5. Capacitors 112 and 114 suppress parasitic oscillation which might otherwise occur due to the varying impedance characteristics of the batteries 110.
All components of the system 10, with the exception of microphone transducer and preamplifier 12 and earphone 48 are contained in a small portable package which may be mounted on the belt of the operator. Microphone transducer and preamplifier 12 may be mounted on a harness at chest level. Earphone 48 is, of course, mounted in the ear. Alternatively, headphones may be supplied in place of earphone 48.
In operation, the operator may select any or all of the channels 18, 20 and 22 to listen to sounds in the infrasonic, sonic, or ultrasonic ranges, respectively. It has been found that when the operator is moving, it is often convenient to activate only the sonic channel 20, since considerable infrasonic and ultrasonic noise is generated as the operator walks. When the operator remains stationary, the infrasonic or ultrasonic channels may be activated, thus permitting the operator to detect sounds in these frequency ranges that represent activities which do not produce sounds in the sonic range that are detectable at the same distance. Accordingly, the ability of the operator to detect, identify, and classify sounds is considerably enhanced.
It has been determined that filter cut-off frequencies as described above produce highly satisfactory results. However, other filter cut-off frequencies are possible. For example, it has been determined that considerable sonic energy is present in the lower frequencies within the range of human hearing of, for example, roughly 50 to 200 KHz. Sounds in these frequency ranges may thus mask desired sounds in the upper sonic range. Accordingly, the operator may select only the sonic channel for operation. At certain times, when it is suspected that activities may be occurring which generate infrasonic waves, the sonic channel may be deactivated and the infrasonic channel activated. Sounds of interest, such as heavy vehicles and helicopter rotor chop, may then be detected. Cut-off frequencies of 200 Hz, that is, above the lower frequency limit of human hearing, for filters 24 and 32 thus provide superior performance.
Clandestine communication between multiple operators each equipped with systems 10 is possible in the ultrasonic range by lightly tapping certain objects together to produce sounds inaudible in the sonic range but readily detectable in the ultrasonic range.
It is possible to provide some of the benefits of the present invention using a system 10 which includes only one of the channels 18 or 22. However, increased performance is possible in a system including two or more of channels 18, 20, or 22 over that provided by only a single channel, due to the varying nature of sound sources and propagation characteristics in the various frequency ranges.
It will be apparent to those skilled in the art that various modifications and variations can be made in the detection system of the present invention, and in the construction of the specific circuitry, without departing from the scope or spirit of the invention. For example, the various filters can have more or fewer poles depending on the specific characteristics desired and the ultimate cost of the system. Also in certain applications output transducers such as strip chart recorders or threshold alarms may be substituted for earphone 48. Thus, it is intended that the present invention cover modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
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Apparatus for enhancing human hearing includes a pair of parallel-connected directional microphone elements responsive to frequencies ranging from below the audible frequency range to above the audible frequency range, the microphone elements facing in opposite directions and mounted in a parabolic reflector. The microphone element output signals are separated into infrasonic, sonic, and ultrasonic channels by filters. The infrasonic and ultrasonic channel signals are processed by a frequency heterodyning process to signals having frequencies within the range of human hearing. The channel signals are then selectively combined, amplified, and supplied to an earphone to render audible sounds outside the range of human hearing and aid in the detection, location, and classification of events of interest.
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BACKGROUND OF THE INVENTION
1. Field of the Invention:
The present invention relates to a logic circuit, and more particularly to an ECL (Emitter Coupled Logic) circuit suitable for being formed in a semiconductor substrate.
2. Description of the Prior Art:
The ECL circuit in the prior art is formed of a current switch section receiving an input logic signal and an emitter follower output section. The current switch section includes a reference transistor, at least one switching transistor having an emitter connected to the emitter of the reference transistor, and a current source transistor connected to the commonly connected emitters of the reference and switching transistors. The base(s) of the switching transistor(s) receives the input logic signal(s) and the base of the reference transistor is held at a reference voltage generated from a first constant voltage source. The base of the current source transistor is held at another constant voltage generated from a second constant voltage source. By the suitable circuit arrangement of the second constant voltage source, the constant voltage can be made free from temperature variation. The small variation of the reference voltage does not affect the operating current. Thus, the operating current is not changed by the change in the reference and constant voltages.
The current switch section of the ECL circuit further includes a first load resistor connected to the collector of the reference transistor, a second load resistor connected in common to the collector(s) of the switching transistor(s), and an emitter resistor of the current source transistor. The ECL circuit further comprises an emitter-follower transistor having a base connected to an output node between the second load and the switching transistor(s) and an emitter resistor thereof, in the emitter follower output section. The resistances of those four resistors employed in the ECL circuit have temperature dependency which is not compensated by circuit arrangement. For example, the diffusion resistor formed by an impurity diffusion into a semiconductor substrate has a positive temperatre coefficient. Therefore, if the operating temperature changes, the current flowing through the ECL circuit changes. More specifically, if the resistors have a positive temperature dependency, the operating current decreases with an increase in temperature.
Generally, transistor circuit has such tendency that the delay time of the output signal from the input signal becomes large as the operating current decreases. Therefore, the ECL circuit has a drawback that the delay time depends on the operating temperature. Furthermore, since the operating temperature changes by ambient temperature and operating condition, the time delay is unstable and unpredictable. Due to the instability of operating current, power consumption is also unstable and unpredictable. These facts make the system design difficult.
SUMMARY OF THE INVENTION
The primary object of the present invention is to provide a logic circuit having a delay time free from an affection from the variation in the operating temperature.
Another object of the present invention is to provide a logic circuit having little temperature dependency of total power consumption.
Still another object of the present invention is to provide a logic circuit which is capable of making the system design easy and suitable for being formed in a semiconductor integrated circuit.
According to the present invention, there is provided a logic circuit comprising a current switch section formed of transistors and resistors and receiving an input logic signal to be compared with a reference voltage and an output section formed of at least a transistor and a resistor and producing an output signal in response to the output from the current switch section, the resistors in the current switch section having resistances of a negative or positive temperature coefficient, the negative or positive sign thereof being opposite so that of the temperature coefficient of the resistor in the output section. The current switch section is preferably of an emitter-coupled type and uses polycrystalline resistors as the resistors. The output section is preferably an emitter follower stage and uses a diffused resistor as the resistor.
The present invention makes the sign of the temperature coefficient of the resistor different between that in the current switch section and that in the output section. Therefore, when the operating temperature changes, the changes in the currents flowing through the current switch section and the output section are opposite to each other. Thus, the change in the total power consumption becomes very small by the mutual compensation. For the same reason, the change in the time delay of the output signal also becomes very small.
Thus, the logic circuit of the present invention has stable and predictable total power consumption and time delay of output signal. Since a semiconductor integrated circuit has a limited power consumption, the stable and predictable total power consumption is convenient for the design of a semiconductor integrated circuit using the logic circuit of the present invention. Since a matching of signal timing is important in logic systems, the stable and predictable time delay of output signal facilitates the design of a system using the logic circuit of the present invention.
Furthermore, the resistors having negative and positive temperature coefficients are easily achieved by using diffused resistor and polycrystalline resistor. These resistors may be formed on a semiconductor chip through ordinary manufacturing process. Thus, the logic circuit of the present invention is suitable for being formed in a semiconductor integrated circuit.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and further objects, features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a circuit diagram of an ECL circuit in the prior art;
FIG. 2 is a graphic view for explaining the relationship between the current flowing though the current switch section of FIG. 1 and the time delay of the output therefrom;
FIG. 3 is a graphic view for explaining the relationship between the current flowing through the emitter follower output section of FIG. 1 and the time delay of output therefrom;
FIG. 4 is a circuit diagram of an embodiment according to the present invention;
FIG. 5 is a circuit diagram of an example of the second constant voltage generator;
FIG. 6 is a circuit diagram of an example of the second constant voltage generator;
FIG. 7 is a sectional view of circuit elements formed in a semiconductor integrated circuit and used in the embodiment of the present invention;
FIG. 8 is a graphic view for explaining the relationship between the signal time delays in the respective sections and the whole circuit and the operating temperature; and
FIG. 9 is a graphic view for explaining the relationship between the power dissipation in the respective sections and the whole circuit and the operating temperature.
The ECL circuit in the prior art is shown in FIG. 1 and composed of a current switch section including a reference transistor Q 2 , at least one switching transistor Q 1 , a current source transistor Q 3 , a first and second load resistors R 2 and R 1 and an emitter resistor R 3 , a first constant voltage source 1 generating a reference voltage V REF and a second constant voltage source 2 generating a constant voltage V cs and an emitter follower output section including a transistor Q 4 and a resistor R 4 . The current source transistor Q 3 has a base receiving the constant voltage V cs and an emitter connected with the emitter resistor R 3 and constitutes a current source. The switching and reference transistors Q 1 and Q 2 have emitters connected in common to the collector of the current source transistor Q 3 and collectors connected respectively to the second and first load resistors R 1 and R 2 . An input logic signal is applied to the base of the switching transistor Q 1 through an input terminal 3. The reference voltage V REF is applied to the base of the reference transistor Q 2 . The input signal is compared with the reference voltage V REF . A result of the comparison is derived at the connection point between the collector of the switching transistor Q 1 and the second load R 1 and applied to the base of the emitter follower transistor Q 4 . The final output signal is produced at an output terminal 4 through the emitter of the transistor Q 4 .
The second constant voltage source 2 is generally arranged to produce a constant voltage V cs free from the temperature variation. By such arrangement, the ECL circuit produces an output signal having a constant logical amplitude. In other words, the operating current is kept constant by the stable and constant voltage V cs . The small variation of the reference voltage V REF changes a comparison reference of the input logic signal but does not affect the operating current.
However, resistance values of the resistors used in the ECL circuit have temperature dependencies. When the ECL circuit is formed in a semiconductor integrated circuit, the resistors are formed as diffused resistors which use impurity-diffused regions. Such diffused resistors have resistances of positive temperature coefficient. With the increment of temperature, their resistance values increase.
While the base of the transistor Q 3 is held at a stable and constant voltage V cs , the resistance of the resistor R 3 connected at the emitter of the transistor Q 3 has a positive temperature coefficient. Therefore, the operating current I cs of the switching section decreases when the operating temperature rises. Similarly, the operating current I EF of the emitter follower output section is affected by the tempeature coefficient of the resistance of the resistors R 4 , R 3 and R 1 . These relationship can be expressed by the following equations (1) and (2). ##EQU1## where: V cc . . . , a power voltage;
V F . . . a base-emitter voltage of transistors Q 3 and Q 4 ;
V L . . . a logical amplitude which nearly equals ##EQU2## ΔT j . . . an increment of operating temperature; α . . . a temperature coefficient of resistances of the resistors;
R 4 ,R 3 ,R 1 . . . resistances of the resistors R 4 , R 3 and R 1 .
The time delays at the current switch section and the emitter follower output section increase with decrements of operating currents I cs and I EF , as shown in FIGS. 2 and 3. That is, in the respective sections, the operating currents decrease as the operating temperature increases, causing enlarged delay times in the respective sections. These respective delay times are accumulated in the delay time of the final output signal. since the delay times depend on the operatng temperature, the delay time of the final output is unstable and unpredictable in actual operating condition. Therefore, the design of logical system using such ECL circuits encounters difficulty in matching the signal timing.
The temperature dependencies of the operating currents is another cause of unstable and unpredictable power consumption. Especially, the allowable power consumption in a semiconductor integrated circuit is limited. Therefore, the unstable and unpredictable power consumption makes the design of the semiconductor integrated circuit using such ECL circuits difficult. Thus, the ECL circuit in the prior art is not suitable for being formed in a semiconductor integrtated circuit.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 4 shows a embodiment of the present invention which has a circuit similar to the ECL circuit shown in FIG. 1. The difference is in that the resistors R 1 ', R 2 ' and R 3 ' in the current switch section are formed in a semiconductor integrated circuit by using polycrystalline silicon layers deposited on the silicon chip, while the resistor R 4 ' in the emitter follower output section is formed by using an impurity-diffused region formed in the single crystal region of the silicon chip. As a result, the former resistors have a negative temperature coefficient and the latter resistor has a positive one. Those resistors R 1 ', R 2 ' and R 3 ' and the resistor R 4 ' are shown in FIG. 7 which will be explained later.
An example of the second constant voltage source 2 is shown in FIG. 5. A diode-connected transistor Q 11 and a resistor R 11 are serially connected between the output terminal 6 of the constant voltage V cs and the ground line (V GND ). In parallel with the diode-connected transistor Q 11 , a series connection of a base-emitter junction of a transistor Q 12 and a resistor R 12 is connected. The collector of the transistor Q 12 is connected with resistors R 13 , R 14 and R 15 and a capacitor C 12 . The other end of the resistor R 13 is grounded. A base-emitter junction of a transistor Q 13 is connected between the other end of the resistor R 15 and the ground line (V GND ). The capacitor C 12 is connected in parallel with the resistor R 15 and the base-collector junction of the transistor Q 13 . The other end of the resistor R 14 s connected with the output terminal 6 and an emitter of a transistor Q 14 having a collector connected with the power line (V cc ) and a base connected with resistors R 16 and R 17 and a capacitor C 11 . The other end of the resistor R 16 is connected with the collector of the transistor Q 13 and the capacitor C 12 . The other end of the resistor R 17 is connected with the power line (V cc ). The other end of the capacitor is grounded to the ground line (V GND ). The constant voltage V cs produced at the output terminal 6 has no temperature coefficient.
An example of the first constant voltage source shown in FIG. 6 uses the constant voltage V cs produced from the second constant voltage source 2 and applied through an input terminal 7. The constant voltage V cs is applied to a base of a transistor Q 15 which has an emitter grounded through a resistor R 19 and a collector connected to the power line (V cc ) through a parallel connection of a resistor R 18 and a capacitor C 13 . The voltage obtained at the collector of the transistor Q 15 is applied to a base of a transistor Q 16 having a collector connected to the power line (V cc ) and an emitter connected to a resistor R 20 and an output terminal 8. The other end of the resistor R 20 is grounded to the ground line (V GND ). Since the reference voltage V REF obtained at the output terminal 8 is produced from the constant voltage V cs which has no temperature coefficient, the temperature coefficient of the reference voltage V REF is very small.
By use of those examples of the first and second constant voltage generators 1 and 2, the operating currents flowing through the ECL circuit shown in FIG. 4 may not depend on the temperature dependencies of the reference voltage V REF and the constant voltage V cs . Another cause of the temperature dependency of the operating currents is the temperature coefficients of the resistors R 1 ' through R 4 '. In accordance with the embodiment shown in FIG. 4, the resistors R 1 ', R 2 ' and R 3 ' are polycrystalline resistors having resistances of a negative temperature coefficient and the resistor R 4 ' is a diffused resistor having a resistance of a positive temperature coefficient.
Those polycrstalline resistors and diffused resistor may be formed as shown in FIG. 7. On a P-type silicon substrate 11, N + -type buried layers 14 and an N-type epitaxial layer are formed. The N-type epitaxial layer is divided into a plurality of N-type regions 13 and 13' by a formation of a P + -type isolation region. In one of the N-type region 13', a bipolar transistor 72 is formed by diffusing an N + -type collector contact region 17, a P-type base region 18, a P + -type base contact region 19 and an N + -type emitter region 20. A thick SiO 2 layer 21 is formed outside the element regions and between the N + -collector contact region 17 and the P-type base region 18. The thick SiO 2 layer 21 is produced by a thermal oxidation. The electrodes of emitter, base and collector are led out by a doped polycrystalline layer 22. The doped polycrystalline layer is once formed all over the surface, and then undesired part of the polycrystalline layer except for the wiring regions and polycrystalline resistor regions are converted into SiO 2 layer 23 by the selective thermal oxidation. On the polycrystalline layers 22 and the SiO 2 layer 23, another SiO 2 layer 24 is deposited by a process of vapor deposition.
The diffused resistor 71 is formed in the N-type region 13 which is a single crystal region. A P-type region 15 having a sheet resistance of 8 KΩ/□ is formed in the N-type region 13. At two separated portions of the P-type region 15, P + -regions 16 are formed for contacting with the doped polycrystalline layers 22. The interconnection with other circuit elements is made by A1 wiring layers 25. The diffused resistor 71 has a resistance of positive temperature coefficient which mainly depends on the sheet resistance of the P-type region 15.
The polycrystalline resistor 73 is formed by the doped polycrystalline layer 22' having a sheet resistance of 4 KΩ/□ and deposited on the SiO 2 layer 21. The doped polycrystalline layer 22' is deposited simltaneously with other doped poycrystalline layer 22. The interconnection with other circuit elements is made by A1 wiring layers 25. The polycrystalline resistor 73 has a resistance of negative sign temperature coefficient, if the sheet resistance of the doped polycrystalline layer 22' is larger than a few hundreds ohms/□. Pratically, the sheet resistance is selected more than three hundreds ohms/□ for the resistors having a negative sign temperature coefficient of resistance. For obtaining a positive sign temperature coefficient of resistance, the sheet resistance is selected as lower than 100 ohms/□.
Turning back to FIG. 4, when the operating temperature rises by ΔT(°C.), it changes operating current I' cs at the current switch section of transistors Q 1 , Q 2 and Q 3 and the operating currents I' EF at the emitter follower output section. The changing values ΔI' cs and ΔI' EF of the operating currents I' cs and I' EF are as follows; ##EQU3## where, αis a temperature coefficient of resistances of the resistors R 1 , R 2 and R 3 and β is that of the resistor R 4 .
According to this embodiment, since the signs of the temperature coefficients "α" and "β" are respectively negative and positive, the operating currents I' cs and I' EF increase and decrease, respectively. The time delay tpd(cs) of the signal at the current switch section becomes short, while the time delay tpd(EF) of signal at the emitter follower output section becomes long. The change in total time delay becomes small as exemplarily shown in FIG. 8. Since the total time delay does not change widely by temperature variation, the circuit design using the ECL circuit becomes very easy.
The power consumption will now be explained. The total power consumption P W can be expressed as follows;
P.sub.W =(I'.sub.EF +I'.sub.cs)×V.sub.cc . . . (5)
When the operating temperature rises by ΔT, the total power consumption P' W changes as follows;
P.sub.W ={(I'.sub.EF -ΔI'.sub.EF)+(I'.sub.cs +ΔI'.sub.cs)}×V.sub.cc (6)
The change in power consumption ΔP W is as follows;
ΔP.sub.W =(-ΔI'.sub.EF +ΔI.sub.cs)×V.sub.cc (7)
These relationships between the power consumption and the temperature change in the respective sections and the whole circuit are shown in FIG. 9 in which P W (cs) and P W (EF) are power consumptions in the current switch section and the emitter follower output section. The ECL circuit of the present invention does not change widely its power consumption and is suited for use in a semiconductor integrated circuit in which the allowable power consumption is limited.
The temperature coefficients of the resistances of the diffused resistor and the polycrystalline resistor may be controlled by sheet resistances in the diffused region 15 and the polycrystalline layer 22'. Therefore, the controls of the time delay and the power consumption may be achieved by the normal techniques used in a semiconductor integrated circuit. Furthermore, by adjusting those sheet resistances, the temperature dependencies of the signal time delay and the power consumption may be made zero.
Although the diffused resistor having a resistance of positive temperature coefficient and the polycrystalline resistor having a resistance of negative temperature coefficient are respectively used in the emitter follower output section and the current switch section, they may be reversely used. That is, the diffused resistor and the polycrystalline resistor may be respectively used in the current switch section and the emitter follower output section and even in that case, the changes in total signal time delay and the whole power consumption are equally made small or zero. The temperature coefficient of the resistance of the polycrystalline resistor can be controlled from negative to positive by adjusting its sheet resistance. Therefore, the resistors in both of the current switch section and the emitter follower output section may be made with polycrystalline resistors only. That is, the resistor(s) used in one of the sections is the polycrystalline resistor(s) made by a polycrystalline layer having a sheet resistance smaller than 100 ohms/□, and the resistor(s) used in the other section is that made by a polycrystalline layer having a sheet resistance larger than 300 ohms/□. It is obvious to the skilled in the art that the base of the transistor Q 4 in FIG. 4 may be connected with the collector of not the switching transistor but the reference transistor Q 2 to obtain an inverted output signal.
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A logic circuit such as an emitter coupled logic includes a current switch section formed of transistors and resistors and comparing an input signal with a reference voltage and an output section formed of at least a transistor and a resistor and producing an output signal in response to the comparison result, the resistors in the current switch section being polycrystalline resistors, for example, having a negative temperature coefficient of resistance whose sign is opposite to that of the resistor, for example a diffused resistor, having a positive temperature coefficient in the output section.
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RELATED APPLICATIONS
The present invention was first described in and claims the benefit of U.S. Provisional Application No. 61/903,477, filed Nov. 13, 2013, the entire disclosures of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates generally to a flood gate system placed in front of a doorway and sealed to a structure supporting the doorway. When floodwaters become imminent, the slide panel is inserted into the slide panel guides and slid down to provide a waterproof gate.
BACKGROUND OF THE INVENTION
When disaster strikes, every second counts in preventing the loss of life or property. This is especially the case when dealing with floods where water can rise at alarming rates, engulfing entire towns, and destroying family belongings that have been collected over many generations. As a result, family heirlooms such as photographs, antiques, and other irreplaceable items risk being lost forever, without hope for recovery. This being the case, people are willing to go to great lengths to ensure the safety of their homes and belongings during floods caused by hurricanes, tornadoes, and floods. Unfortunately, with the exception of sandbags, dikes, and massive construction projects, there is little that can be done to protect ones home or building against the ravages of a flood. Accordingly, there is a need for a means by which flood waters from natural disasters can be restricted from buildings and homes, in a manner that is quick, easy, and effective while doing it in a cost-effective manner.
SUMMARY OF THE INVENTION
The disadvantages of the prior art are overcome by the present invention in providing a flood gate system for a doorway utilizes a frame having a slide panel guide located at lateral and bottom edges thereof. A slide panel is slidably adjusted within the slide guides. The slide panel guides, perimeter edges of the frame, and bottom of the slide panel are provided with seals to provide a waterproof abutment and securement of the system. The slide panel guide is permanently affixed to the front frame of a doorway and sealed to the structure supporting the doorway frame. When floodwaters become imminent, the slide panel is inserted into the slide panel guide and slid down to provide a waterproof gate for the doorway. The use of the flood gate system safely controls flood waters at a doorway resulting from natural disasters, in a manner that is quick, easy, and effective, thus protecting personal property and belongings.
BRIEF DESCRIPTION OF THE DRAWINGS
The advantages and features of the present invention will become better understood with reference to the following more detailed description and claims taken in conjunction with the accompanying drawings, in which like elements are identified with like symbols, and in which:
FIG. 1 is an environmental view of a flood gate system for a doorway 10 in accordance with the preferred embodiment of the present invention;
FIG. 2 is an isometric view of a slide panel guide 20 of the flood gate system for a doorway 10 attached to a building 100 in accordance with the preferred embodiment of the present invention; and,
FIG. 3 is an isometric view of a slide panel 50 of the flood gate system for a doorway 10 in accordance with the preferred embodiment of the present invention.
DESCRIPTIVE KEY
10 system
20 slide panel guide
22 side member
24 base member
26 first side flange
28 second side flange
32 web member
34 throat
36 first aperture
38 second aperture
42 third aperture
46 threaded fastener
50 slide panel
54 blocking
52 core
56 sheathing
58 handle
62 seal
100 building
104 door
120 pad
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The best mode for carrying out the invention is presented in terms of its preferred embodiment, herein depicted within FIGS. 1 through 3 . A person skilled in the art will appreciate that many other embodiments of the invention are possible without deviating from the basic concept of the invention. Any such work around will also fall under scope of this invention. While only one particular configuration is shown and described that is for purposes of clarity and disclosure and not by way of limitation of scope.
The present invention describes a flood gate system for a doorway (herein referred to as the “system”) 10 , which provides a means to place a temporary, sealed barrier into a permanent frame at a doorway of a building 100 to obviate the entrance of floodwaters. Referring now to FIG. 1 , an environmental view, and FIG. 2 , an isometric view of the slide panel guide 20 , of the system 10 according to the preferred embodiment of the present invention, are disclosed. The system 10 includes a slide panel guide 20 and a slide panel 50 . The slide panel guide 20 is adapted to be attached to the building 100 and the slide panel 50 is inserted into the slide panel guide 20 in order to seal off access to the door 104 so as to not allow water therein. The slide panel guide 20 is configured as a formed, or stamped, metal piece with two (2) parallel vertical side members 22 and an interconnecting horizontal base member 24 . Each of the side members 22 and the base member 24 are generally “C”-shaped channels with a first side flange 26 parallel to a second side flange 28 and a perpendicular web member 32 therebetween. The first side flanges 26 , the second side flanges 28 , and the web members 32 of the two side members 22 and the base member 24 define the finite space between them as the throat 34 of the slide panel guide 20 . The slide panel guide 20 is preferably composed of aluminum or some other metal which is both economical and resistant to corrosion. However, other materials, such as an extruded rigid polymer or a high-strength composite, may be utilized without limiting the scope of the system 10 .
As shown in FIG. 1 , the slide panel guide 20 will be oriented with the first side flanges 26 of the side members 22 and the base member 24 abutting a doorway of a building 100 . Disposed in an evenly spaced pattern along the first side flanges 26 is a plurality of first apertures 36 , each being countersink as oriented toward the doorway. Disposed in a matching pattern along the second side flange 28 of the side members 22 and the base member 24 , is an equal and corresponding plurality of second apertures 38 . The second apertures 38 are aligned opposite from the first apertures 36 and are of sufficient size so that a tool, such as a screwdriver, may be inserted through a second aperture 38 to reach and drive a threaded fastener 46 into an opposing first aperture 36 to secure the slide panel guide 20 to the building 100 .
It should be appreciated that the second aperture 38 may be larger in diameter than the first aperture 36 , or of any comparative size, to permit the proper clearances for the threaded fastener 46 and a driving tool. The threaded fastener 46 would preferably be of a flat head, or countersunk, type in order to thread entirely into its particular first aperture 36 and not have any portion projecting into the throat 34 . Additionally, disposed along the web member 32 of the base member 24 in a preferably evenly spaced pattern is a plurality of third apertures 42 . These third apertures 42 are countersink on the upper surface of the web member 32 of the base member 24 to allow the heads of the downwardly driven fasteners 46 to be recessed. These downwardly driven fasteners may engage the frame other hard base surface the frame may be attached to.
Referring now to FIG. 3 , an isometric view of the slide panel 50 , of the system 10 according to the preferred embodiment of the present invention, is disclosed. The slide panel 50 would preferably be composed of a thin gauge metal sheathing 56 , such as aluminum sheet, formed around a light-weight core 52 , such as a closed-cell polymer foam. It is understood that other materials and methods of construction may be utilized for the sheathing 56 , such as an epoxy coated steel sheet, and for the core 52 without limiting the scope of the system 10 . It may also be necessary to add some type of framing to the core 52 to increase the structural rigidity of the slide panel 50 , however, it is understood that any such eventualities do not modify the scope or intent of the present system 10 and this preferred embodiment does not preclude any other embodiment.
Disposed upon the upper edge of the slide panel 50 are preferably two (2) handles 58 to aid in the manipulation and transport of the slide panel 50 . The handles 58 are secured to the slide panel 50 by means of threaded or other type fasteners retained in blocking 54 . The blocking 54 , as seen in the cut-away portion of FIG. 3 , is a reinforcing insert, preferably comprised of wood, or other suitable material, formed into the core 52 to withstand certain loading normally beyond the capacity of the constituent core 52 material.
Disposed along the side and lower edges of the slide panel 50 is a seal 62 . The seal 62 may be a single piece or separate but contiguous seals attached to, or incorporated into, the sheathing 56 . In this manner, a watertight barrier is formed between the slide panel 50 and the side members 22 and the base member 24 of the slide panel guide 20 after the slide panel 50 has been inserted into the slide panel guide 20 . The seals may be configured to have any grooves, channels, or other surface features so as to optimize the exclusion of water and debris from the system 10 . Alternately, the seals may extend to some portion of the front and the rear faces of the slide panel 50 so as to form a barrier which would involve the first side flange 26 and the second side flange 28 of the members 22 , 24 .
The preferred embodiment of the present invention can be utilized in a simple and straightforward manner with little or no training. A layer of a substance, such as caulk, would be applied to the face of the first side flange 26 of each member 22 , 24 prior to securing the slide panel guide 20 to the building 100 so as to fill any gaps or irregularities to achieve a water-tight seal. The substance used to achieve this seal would preferably not shrink upon setting or drying and would maintain good adhesion between the first side flange 26 and the building 100 over an extended period of time, such as a good quality silicone or latex caulk. However, the substance used for this sealing is not the subject of the present system 10 and as such may encompass any material, or materials, capable of bringing about the water-tight seal.
As a preparatory step to the installation of the slide panel guide 20 on a building 100 , a pad 120 would have to be prepared. The pad 120 is a new, or an existing block, preferably composed of concrete, into which threaded inserts have been secured for the purpose of retaining the threaded fasteners 46 installed in the base flange 32 of the base member 24 . The requirements of the pad 120 would be that it be essentially coplanar with the base flange 32 of the base member 24 after the slide panel guide 20 is attached to the building 100 . Prior to attaching the slide panel guide 20 to the building 100 water-tight seals, as previously discussed, would be installed between the slide panel guide 20 and the building 100 and between the slide panel guide 20 and the pad 120 .
After initial purchase or acquisition of the system 10 , it would be installed as indicated in FIG. 1 . The method of installing and utilizing the system 10 may be achieved by performing the following steps: acquiring a model of the system 10 having a size to adequately cover the desired door; preparing the pad 120 to accept the base member 24 of the slide panel guide 20 by making the necessary adjustments to the level of the pad 120 and installing the necessary threaded inserts to retain the threaded fasteners 46 ; using the slide panel guide 20 as a template and marking the locations for holes to be drilled into the building 100 for threaded fasteners 46 ; making the appropriate sized holes depending on the materials of construction of the building 100 for the threaded fasteners 46 ; positioning the slide panel guide 20 against the building and pad 120 with caulk or other sealing material in place; fastening the slide panel guide in position by securing the threaded fasteners 46 into the walls of the building 100 and into the pad 120 ; and prior to the weather event or other such happenstance which results in flooding, installing the slide panel 50 into the throat 34 of the slide panel guide 20 using the handles 58 . The slide panel 50 may be removed from the slide panel guide 20 and stored in a convenient location after the flood has subsided. Subsequent usage of the system 10 will not require execution the steps involved with attaching the slide panel guide 20 to the building 100 .
The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention and method of use to the precise forms disclosed. Obviously many modifications and variations are possible in light of the above teaching. The embodiment was chosen and described in order to best explain the principles of the invention and its practical application, and to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions or substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but is intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention.
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A flood gate system for a doorway utilizes a frame having a slide panel guide located at lateral and bottom edges thereof. A slide panel is slidably adjusted within the slide guides. The slide panel guides, perimeter edges of the frame, and bottom of the slide panel are provided with seals to provide a waterproof abutment and securement of the system. The slide panel guide is permanently affixed to the front frame of a doorway and sealed to the structure supporting the doorway frame. When floodwaters become imminent, the slide panel is inserted into the slide panel guide and slid down to provide a waterproof gate for the doorway.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to port collars for use in a tubular string. Specifically, the invention relates to a two-position port collar which can be repeatedly opened and closed and securely retained in each position.
2. Background of the Related Art
Port collars typically have a tubular housing which can be made up into a tubular string to form a part thereof. The port collar has a sliding sleeve disposed therein which may be used to selectively communicate fluid flow between an annular area of the well and an interior of the tubing string. In one example, a port collar is installed in a tubular string in a closed position and the tubular string is then inserted into a wellbore, locating the port collar at a predetermined depth in the well. Packing elements are installed above and below the port collar to isolate a specific zone of the annulus. Thereafter, the sliding sleeve of the port collar is remotely opened and the interior of the tubular is placed into communication with production fluid in the annulus. The port collar may also be used to permit fluid flow from the interior of the tubing string into the annulus of a well. For example, in cementing deep wells, a two-part cementing job is often used wherein the lower portion of a casing or liner string is cemented and then, using a port collar, the upper annulus is cemented to avoid hydrostatic pressures present in the lower portion of the annulus.
While many port collar designs have been made and used, certain problems exist with current designs. For example, most port collars rely on shear screws or some other type of mechanically shearable connection to unlock the sleeve from an initial position and permit movement of the sleeve to a second position within the collar. In a typical example, the shearable connection holds the sleeve in a closed position and then, when the collar is in the wellbore and ready to be opened, the shearable members are caused to fail with mechanical or hydraulic force. Once the shearable connection has failed, the sleeve is left prone to accidental shifting in the housing, unless it is permanently locked into either an open or closed position.
There is a need therefore, for a port collar that does not rely on a shearable connection to lock the sleeve into position within the housing. There is a further need for a port collar that can be repeatedly shifted and locked into the opened and closed positions. There is yet a further need for an easily shiftable port collar that can be used with other port collars in a single tubular string to create a larger assembly for selectively exposing different areas of an annulus to communication with the interior of the tubing string.
SUMMARY OF THE INVENTION
The present invention generally provides a port collar assembly comprising a housing and a sleeve disposed therein. The sleeve is moveable between a first or opened and a second or closed position relative to the housing. In the closed position, the port collar prevents communication of the fluid between the exterior and interior of the port collar. The assembly includes a locking system for each position comprising ratchet teeth formed on the exterior surface of the sleeve and mating ratchet teeth formed on the interior surface of the housing. One set of mating ratchet teeth are designed to secure the sleeve in an opened position within the housing and a second set of mating ratchet teeth secures the sleeve in a closed position. In one aspect of the invention, the ratchet teeth on the interior surface of the housing are formed on the inner surface of an inwardly biased C-ring disposed in a groove formed in the interior surface of the housing. A plurality of buttons are disposed within apertures formed in the exterior surface of the sleeve and the buttons can be urged in an outward radial direction by a shifting tool disposed within the sleeve. The buttons urge the C-rings into the grooves of the housing and out of engagement with the mating ratchet teeth formed on the surface of the sleeve. In this manner, the sleeve and housing are unlocked from each other and the tool can be shifted to the other position.
In another aspect of the invention, cavities and shifting shoulders are formed on the interior of the sleeve opposite each locking system. Corresponding unlocking and detenting formations are formed on a shifting tool including a formation designed to urge the buttons of the sleeve in a radial outward direction. A shifting surface on the shifting tool, corresponding to a shoulder formed on the interior of the sleeve, allows a force to be applied to move the sleeve to a second location in the housing after being unlocked.
In another aspect of the invention, several port collars are installed in a tubular string in a wellbore. Thereafter, in order to open and close the port collars, a number of shifting tools are run into the well on a run-in string in a pre-determined, spaced-apart orientation. The shifting tool at the lowest point on the string opens each port collar as it passes therethrough. In order to close the port collars, the string of shifting tools is pulled upwards and the shifting tool designed to close the port collars closes each collar as it passes therethrough. By accurately spacing the shifting tools along the run-in string, the direction of the string can be reversed in order to open a certain port collar while leaving the others in a closed position.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings.
It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
FIG. 1 is a partial section view showing the port collar of the present invention. in an open position.
FIG. 1A is an enlarged view of a locking portion of the port collar of FIG. 1 .
FIG. 2 is a partial section view of the port collar in a closed position.
FIG. 3 is a perspective, side view of a shifting tool used to open the port collar including an opening portion and a closing portion.
FIG. 4 is a section view showing the port collar in the open position with a shifting tool installed therein.
FIG. 4A is an enlarged view showing the opening portion of the shifting tool engaged in the sleeve of the port collar.
FIG. 5 is a section view showing a collet-like function of the shifting tool.
FIG. 5A is an enlarged view thereof.
FIG. 6 is a side view of a wellbore showing a plurality of port collars disposed on a string of tubulars.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a side view, partially in section of the port collar 200 of the present invention. The port collar 200 includes a housing 205 , which is typically connected at each end to a tubular string (not shown). The housing 205 includes a plurality of housing apertures 210 formed in a wall thereof and constructed to align with sleeve apertures 212 formed in a wall of a sleeve 206 when the port collar 200 is in an open position as in FIG. 1 . The sleeve 206 is disposed within the housing 205 and is installed therein in a certain rotational orientation which is predetermined and is secured with lock screws or set screws (not shown) between the housing 205 and the sleeve 206 . Axial movement of the sleeve 206 within the housing 205 is limited by stops 215 , 217 formed at each end of the interior of the housing 205 . The stops prevent axial movement of the sleeve 206 within the housing beyond that movement necessary to locate the sleeve 206 in the open or closed position.
The port collar 200 includes a first locking system, generally labeled 300 to retain the sleeve 206 in a closed position and a second locking system 301 to retain the sleeve in an open position. In FIG. 1, locking system 301 is engaged and the port collar 200 is locked in the open position with fluid communication possible between the inside and outside of the port collar 200 through aligned apertures 210 , 212 . The sleeve 206 is prevented from axial movement in a first direction by stop 217 and in the direction of the closed position by engaged locking system 301 .
Each locking system 300 , 301 includes locking surfaces formed on the perimeter of the sleeve 206 and locking surfaces formed on the inner surface of the housing 205 . The surfaces prevent the sleeve 206 from moving within the housing 205 in one direction. FIG. 1A is an enlarged view showing a portion of engaged locking system 301 . Specifically, the locking surface formed on the sleeve 206 includes ratchet teeth 325 extending around the sleeve perimeter. In the preferred embodiment, the mating locking surface of the housing 205 includes at least one groove 365 formed in the inner surface of the housing with an inwardly biased C-ring 370 disposed therein. On the inside surface of the C-ring 370 , facing the sleeve 206 , ratchet teeth 375 are formed and are designed to interact with ratchet teeth 325 formed on the exterior of the sleeve 206 such that the sleeve 206 is prevented from axial movement in the housing 205 in a first direction when the mating teeth 325 , 375 of the sleeve and the C-ring are engaged. As depicted in FIG. 1A, the engaged ratchet teeth 325 , 375 will move across each other with little resistance in a first direction but will interfere with each other preventing movement in a second direction. Specifically, the design allows the ratchet teeth 325 , 375 to move across each other as the port collar 200 is shifted to the open position shown in FIG. 1 . Thereafter, the interaction of the teeth 325 , 375 prevent the sleeve 206 from moving back towards the closed position. In the open position therefore, the sleeve 206 is prevented from axial movement in one direction by stop 217 acting between the sleeve 206 and the housing 205 and in the opposite direction by the locking system 301 .
Interspersed with the ratchet teeth 325 on the outer perimeter of the sleeve 206 are at least one button 335 , one of which is visible in FIG. 1 A. The buttons 335 are housed in countersunk apertures 336 formed in the sleeve 206 and a head portion 337 of each button 335 is retained on a reduced diameter shoulder 338 formed in each aperture. The buttons can be urged outwardly radially by a shifting tool described hereafter. The placement of apertures 336 with the buttons 335 therein correspond to the location of the ratchet teeth 325 formed on the outer surface of the sleeve 206 such that the buttons 335 , when urged outwards, extend out above the ratchet teeth 325 . By urging the buttons outward, the head portion 337 of the buttons move the inwardly biased C-ring 370 back into the groove 365 and out of engagement with the ratchet teeth 325 of the sleeve. In this manner, the locking system 301 is unlocked and the sleeve 206 can be moved axially within the housing 205 . The number of buttons utilized can be increased for redundancy. Additionally, each locking system can utilize multiple locking surfaces. For example, if a particular tool is run through a port collar and one set of buttons is inadvertently urged outwards thereby disengaging a first C-ring, a second C-ring with its locking surface will remain engaged with corresponding ratchet teeth of the sleeve, thereby preventing premature shifting of the port collar.
FIG. 2 is a partial section view showing the port collar 200 in a closed position with the sleeve apertures 212 out of alignment with the housing apertures 210 . In the closed position, there is no fluid communication between the interior and exterior of the port collar 200 . As with locking system 301 , locking system 300 includes ratchet teeth formed on the exterior of the sleeve 206 and ratchet teeth formed on the inside surface of a C-ring housed in a groove formed on the inside surface of housing 205 . In the closed position, the sleeve 206 is prevented from movement in a first axial direction by stop 215 and in the direction of the open position by the engaged locking system 300 .
Unlocking and shifting of the port collar 200 between the open and closed positions are performed through the use of a shifting tool. FIG. 3 is a perspective view of shifting tool 400 which is comprised of an opening portion 410 and closing portion 450 , each portion having an opposing orientation along the length of the shifting tool. Portions 410 , 450 , when run into the wellbore, are independently seated in the interior of the port collar sleeve 206 . FIG. 3 illustrates the opening portion 410 including a tool oriented to open the port collar 200 and closing portion 450 oriented to close the port collar 200 . The spacing between the opening 410 and closing 450 portions is adjustable depending upon operational conditions and requirements. Each portion 410 , 450 of the shifting tool 400 includes collet-like features with a plurality of slots 436 formed longitudinally within the tool. The slots create fingers 435 therebetween which move in a spring-like manner when force is applied to the surface thereof. In the preferred embodiment, at least four equally spaced fingers 435 are formed around the shifting tool 400 .
Considering the opening portion 410 of the tool in greater detail, each finger 435 includes two unlocking formations 412 , 430 designed to interact with corresponding surfaces on the interior of the sleeve 206 . Unlocking formation 430 also serves to move the sleeve 206 within the housing 205 via engagement between surfaces of the formation 430 and the sleeve 206 . Unlocking formations 412 , 430 include upper surfaces 413 , 431 substantially parallel to the surface of finger 435 and three angled surfaces 414 , 415 , 433 . Unlocking formation 430 also includes one shifting surface 432 substantially perpendicular to the surface of finger 435 . The shifting surface 432 provides a means to urge the sleeve 206 from the closed to the open position as described hereafter. A detenting formation 420 has one upper surface 421 substantially parallel to finger 435 and two angled surfaces 422 , 423 .
Closing portion 450 similarly includes two unlocking formations 470 , 480 and are detenting formation 460 . As with the opening portion, formations 480 , 470 include surfaces 481 , 471 substantially parallel to the surface of finger 435 and three angled surfaces 483 , 472 , 473 . Additionally, shifting formation 480 includes shifting surface 482 substantially perpendicular to finger 435 . A detenting formation 460 includes an upper surface 461 and also a two surfaces 462 , 463 angled to the surface of finger 435 .
Formed in the interior of the sleeve 206 , opposite each locking system 300 , 301 are cavities constructed and arranged to interact with the formations and surfaces of the shifting tool 400 . FIG. 4 is a partial section view of the port collar 200 showing the closing portion 450 of the shifting tool 400 engaged with the corresponding cavities in the sleeve opposite locking system 301 . With the closing portion 450 of the shifting tool 400 inserted, the sleeve 206 may be urged in the direction of stop 215 , mis-aligning the apertures 210 , 212 of the sleeve and housing and closing the port collar 200 . As illustrated in FIG. 4A, an enlarged view of locking system 301 , formations 460 , 470 , 480 of the closing portion 450 of the shifting tool 400 have engaged corresponding cavities of the sleeve 206 . The interior of the sleeve 206 opposite locking system 301 includes two unlocking cavities 430 , 436 and one shifting shoulder 440 constructed and arranged to interact with unlocking formations 470 , 480 and detenting formation 460 formed on the closing portion 450 of the shifting tool 400 . In FIG. 4A, shifting surface 482 of the shifting tool is in contact with shoulder 440 of the sleeve 206 . Surfaces 481 , 471 of formations 470 , 480 have contacted the lower surface 338 of buttons 335 disposed in the sleeve 206 and the buttons have been urged outwards in a radial direction. The head portion 337 of each button 335 has contacted and urged the C-rings 370 into the grooves 365 formed on the interior surface of the housing 205 . In this manner, the ratchet teeth 375 have been moved out of engagement with the mating ratchet teeth 325 (not visible) on the exterior of the sleeve 206 .
With the ratchet teeth 325 , 375 out of engagement, force applied against shoulder 440 by shifting surface 482 will cause the sleeve 206 to move axially within the housing 205 . As the sleeve 206 moves into the closed position, axial movement of the sleeve 206 is limited by stop 215 and locking system 301 will prevent axial movement towards the open position, thereby locking the port collar 200 in the closed position. As visible in FIG. 1, there are two cavities 437 , 434 and a shifting shoulder 436 opposite locking system 300 to interact with formations 412 , 430 and shifting surface 432 of the opening portion 410 of the shifting tool 400 . Locking system 300 is disengaged in a similar manner as locking system 301 and those skilled in the art will appreciate that the foregoing description is equally applicable to locking system 300 .
FIG. 5 is a partial section view of the port collar 200 having been shifted to the open position by the opening portion 410 of the shifting tool 400 . FIG. 5 illustrates the collet-like movement of the fingers 435 allowing the opening portion 410 of the shifting tool 400 to be urged out of engagement with the sleeve 206 . FIG. 5A is an enlarged view showing the interaction of the various surfaces of the shifting tool 410 , sleeve 206 and housing 205 . After the port collar is shifted to the open position and additional axial movement of the sleeve 206 is prevented by stop 217 , continued force applied to the shifting tool will cause a surface 423 of the detenting formation 420 to contact and move downward across an undercut surface 218 of the sleeve 206 formed below stop 217 . The downward component of force exerted upon surface 423 urges the flexible finger 435 downward until shifting surface 432 is no longer in contact with corresponding shoulder 502 of sleeve 206 . In this manner, the shifting tool 400 can be moved out of engagement with the port collar.
Typically, a port collar 200 is placed in a well in the closed position whereby the annular area around the port collar 200 is isolated from the interior of the port collar. In order to open the port collar 200 , a shifting tool 400 is run into the well on a run-in string of tubular. The opening 410 and closing 450 portions of the shifting tool 400 allow the port collar 200 to be opened and then closed again at the completion of some downhole operation. As the shifting tool enters the closed port collar, the opening portion 410 passes through the formations opposite the locking system 301 and subsequently, the opening portion 410 interacts with formations opposite the locking system 300 and the shifting tool becomes fixed within the sleeve 206 . In this position, the shifting tool urges the buttons 335 of the locking system 300 outwards thereby moving the C-rings 370 out of engagement with the ratchet teeth 325 of the sleeve. Continued force applied to the shifting tool 400 will then urge the sleeve 206 down and into the open position. Thereafter, continued force upon the shifting tool 400 causes the collet-like fingers of the opening portion 410 of the shifting tool to collapse and come out of engagement with cavities of the sleeve 206 , as illustrated in FIG. 5 A.
The present invention can also be used in a wellbore wherein numerous port collars 200 are arranged in series at various depths in the well and are then alternately opened or closed by multiple shifting tools run into the well along a run-in string. FIG. 6 is a side view of a wellbore showing a plurality of port collars 200 disposed on a string of tubulars 220 . For example, port collars 200 can be located adjacent formations and then selectively opened to access production fluid. Subsequently, the port collars 200 can be re-closed isolating the interior thereof from the annular well fluid. In other examples, the port collars 200 are opened to permit cement to be injected into the annular area therearound and then re-closed after the cementing process is complete.
As a run-in string with shifting tools installed therein is lowered into a wellbore, the opening tool portion 410 of the shifting tool opens the port collars as it passes therethrough. Closing portion 450 of the shifting tool, because it is designed to operate only while moving in an upward direction through the port collars 200 , passes downward through the port collars 200 with no effect. After the shifting tool 400 has passed through and opened all of the port collars 200 , the run-in string housing the shifting tools can be pulled upwards towards the surface of the well such that the closing portion of a shifting tool 450 will re-close the lower most port collars. Finally, if necessary, the opening portion 410 of the shifting tool 400 can then be lowered back through an intermediate port collar(s), leaving the port collar(s) in the open position. In this manner, port collars are selectively opened and closed in a string of multiple port collars.
While foregoing is directed to the preferred embodiment of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
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The present invention generally provides a port collar assembly comprising a housing and a sleeve disposed therein. The sleeve is moveable between a first or opened and a second or closed position relative to the housing. In the closed position, the port collar prevents communication of the fluid between the exterior and interior of the port collar. In the open position, the port collar permits communication of the fluid between the exterior and interior of the port collar. The assembly includes a locking mechanism for the opened and closed positions comprising ratchet teeth formed on the exterior surface of the sleeve and mating ratchet teeth formed on the interior surface of the housing. The mating ratchet teeth are designed to secure the sleeve in a first position within the housing. A second set of mating ratchet teeth secures the sleeve in a second position.
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FIELD OF THE INVENTION
The present invention relates to surgical drapes and more particularly to a surgical drape specifically adapted to be used in certain endourological procedures, specifically nephroscopy, nephrolithotomy and nephrolithotripsy procedures.
PRIOR ART
Surgical drapes are customarily used in the operating room to protect the site of the operation from possible contamination from bacteria which may be found on other portions of the patient's body or which may be airborne or conveyed to the operative site by operating room personnel. The use of surgical drapes is generally considered to be necessary to isolate the patient from the operating room environment and from the operating room staff. The drapes are usually placed over the patient to completely isolate the patient other than that portion of the patient's body which is the actual site of the surgical procedure.
Surgical drapes which provide some mechanism for the direction of body fluids or operating room fluids have previously been known. For example, U.S. Pat. No. 3,791,382 discloses a surgical drape construction which provides a pocket in the outer surface of the drape to receive fluid runoff from the site of the surgical procedure. U.S. Pat. Nos. 4,076,017 and 4,105,019 disclose surgical drapes in which the pocket is formed on the outer surface of the drape by folding an edge of the drape upon itself and sealing it together. U.S. Pat. No. 4,169,472 discloses a surgical drape which includes an impervious bag used for collecting liquids and other fluids which may be present during the operating procedure. U.S. Pat. Nos. 4,378,794; 4,414,968 and 4,462,396 disclose surgical drapes for cystoscopy procedures and these drapes which include some type of fluid collection bag.
Surgical drapes which include an incise film are also known. An incise film is a clear plastic film with adhesive on the patient contact side of the film. The film is adhered to the patient over the operative site. The surgical incision is made through the film and the patient's skin. Incise films are considered to be advantageous to prevent bacterial migration from the patient's skin which is adjacent the surgical incision site. Examples of such drapes are disclosed in U.S. Pat. Nos. 3,826,253; 4,027,665 and 4,489,720.
Tubing or cord holders of various types have also been used on surgical drapes. Examples of tube or cord holders are disclosed in U.S Pat. Nos. 3,721,234; 3,881,474 and 4,323,062.
Although all of the above-mentioned drapes disclose constructions that can be used to collect fluids and hold tubing, the construction of the drapes is not entirely suitable for endourological procedures generally, and such drapes are not suitable for the newly developed percutaneous nephrolithotripsy procedure. The percutaneous nephrolithotripsy procedure is a method of breaking kidney stones using ultrasonic vibrations. In the procedure, a percutaneous incision is made in the patient, and an angiographic guide wire is inserted into the kidney, aided by fluoroscopy, to the vicinity of the stone. The stone itself can be broken with a nephroscope which has an ultrasonic lithotriptor at the end of the scope. When the ultrasonic lithotriptor is in the vicinity of the stone, ultrasonic vibrations will break up the stone, which can be flushed from the kidney with irrigation fluids. This procedure utilizes very large amounts of irrigation fluids and employs a large number of sophisticated medical instruments including angiographic guide wires, an endoscope, pigtail catheter, dialators, a nephroscopy tube containing the ultrasonic lithotriptor, as well as tubing to direct fluid into the operative site and suction tube to remove excess fluid. Prior to the present invention, there was no surgical drape specifically adapted to be used in the nephrolithotripsy procedure. Because of the large amounts of fluid used and the multiplicity of sophisticated surgical instrumentation that is used in these procedures, drapes which have been developed for other procedures were not suitable for use in the nephrolithotripsy procedure.
SUMMARY OF THE INVENTION
The present surgical drape provides multiple tubing guides to hold liquid and suction tubing in place, as well as to provide for the placement of various wires and ready placement of instruments that are used in nephroscopy procedures. The drape employs a fluid collection bag with a large capacity and has a fenestration which is particularly useful in nephrolithotripsy procedures.
Other features of the present invention will be readily apparent to one skilled in the art from the description of the invention which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of the surgical drape of the present invention.
FIG. 2 is a fragmentary, isometric view of the central region of the drape of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The surgical drape of the present invention is generally shown in FIG. 1. The drape has a main sheet 10, which has a top edge 11, a bottom edge 12 and two opposing side edges 13 and 14. The drape has a lower surface 29 which is in contact with the body of the patient and an upper surface 30 which is opposite the lower surface. The drape has a reinforcement area 31 generally located in the central region on the upper surface of the main sheet. The center of the reinforcement area consists of a plastic film 15. There is a fenestration 16 through the plastic film and the main sheet. There is a transparent plastic film 17 which overlies the fenestration. The plastic film 17 has an adhesive coating on its lower surface which will be in contact with the skin of the patient and which aids in securing the drape to the surface of the skin of the patient. There is a small circular fenestration 18 in the incise film. The portion of the reinforcement, other than the plastic film, and which is shown in the drawing as 32, may be an absorbent nonwoven fabric backed with a plastic film which is secured directly to the upper surface of the main sheet. There are a series of tube holders 19, 20 and 21 attached to the reinforcement area of the drape. The tube holders may be formed by doubling over the reinforcing fabric. One edge of the tube holders is secured to the upper surface of the main sheet, and the other edge is not attached, so that the tube holders may be turned perpendicular to the upper surface of the main sheet. The tube holders have a multiplicity of holes 33 through them to accommodate threading wires and tubings through the holes to keep them in the vicinity of the operative site, which would be the area of the fenestration. The holes 33 in the tube holders are aligned with the holes in the other tube holders. There can be any number of holes in the tube holders, but there should be at least three in each of the tube holders to accommodate the various wires and tubing used in the procedure. The tube holders 21, which are adjacent the fenestration, have extended ends 34 which extend into a plastic fluid collection bag 23 to direct fluid into the bag. The fluid collection bag has a piece of nonwoven fabric or a screen 24 to trap stone particles or dropped instruments. There is a port 25 at the bottom of the bag which may be connected to tubing 26 to empty the bag if necessary. There may also be clamping tabs 22 around the edges of the reinforcement area to provide additional sites to clamp various surgical instruments to the upper surface of the drape. There are flaps 35 at the lower edges of the reinforcement area adjacent the fluid collection bag. These flaps can be bent upward from the upper surface of the main sheet and can be clamped to the tube holders to form instrument bags into which instruments can be placed during the surgical procedure. This is shown in FIG. 2. The edges of the flaps 35 are clamped with surgical clamps to the edges of the tube holders to form a surface into which instruments can be readily placed.
There is a moldable strip 27, made from metal or a moldable plastic, secured on the upper surface of the plastic portion of the reinforcement area between the fenestration and the fluid collection bag. There is a second moldable strip 28 secured to the upper portion of the plastic bag. This is shown in both FIGS. 1 and 2. The strips can be bent and are capable of being maintained in a fixed configuration after bending. This allows the strip 27 to be bent to conform to the body of the patient and the strip 28 to be bent in a concave fashion to allow the fluid collection bag to be maintained in an open condition and assist in directing fluid into the bag.
The small circular fenestration 18 in the incise sheet is used in the procedure to allow the angiographic wires to be fed from the body of a patient and through the fenestration 18 when the drape is placed on a patient. The angiographic guide wires are very often placed in the patient prior to the patient being sent to the operating room. These wires would be placed by the radiology department, as it is necessary that the placement be done with a fluoroscope or other imaging equipment.
The drape may be folded into a compact form to allow the drape to be readily placed on the body of the patient. The incise film 27, which has adhesive on the patient side, is usually covered with a release sheet which is removed from the adhesive prior to the placement of the drape on the patient. When the drape is placed on the patient, the release sheet is removed, the angiographic guide wires would be fed through the fenestration hole 18 and the incise sheet 17, and then the drape would be placed on the patient. After the drape is in place on the patient, the various wires and tubes for the instruments used in the procedure may be threaded through the holes 33 in the tubing holders 19, 20 and 21 to locate the wires and tubes in the vicinity of the fenestration 16 in the drape.
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A surgical drape for endourological procedures is disclosed. The drape has a plurality of tube holders on the surface of the drape, a fluid collection bag with strips to hold the bag open during the procedure, and a fenestration specifically adapted for endourological procedures.
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BRIEF SUMMARY OF THE INVENTION
This invention relates to an identification bracelet, and more particularly, to a disposable hospital identification bracelet with which a photograph or other pictorial likeness the wearer may readily be associated.
In conventional modern-day hospital practice, when a patient is admitted, he or she is immediately provided with an identification bracelet which states the patient's name as well as other information, such as, typically, an identification number, attending physician's name, hospital service to which the patient is admitted, blood type and the like. Similar information is placed on a chart, which accompanies the patient if the patient is moved within the hospital.
In one presently used form of identification bracelet, the bracelet is a tubular band, into which a slip of paper or light cardboard, upon which the indicia is typewritten, may be inserted. Typically, in the use of such identification bracelets, after preparation of the information-bearing slip and insertion of it into the bracelet, the bracelet is sealed about the patient's wrist by swaging or deforming a metallic clasp. The band is removed only when the patient is discharged.
Notwithstanding nearly universal usage of some form of patient identification, it occasionally happens that medication is given to or procedures performed upon the wrong patient. Such errors, which obviously can have disastrous consequences, often occur when the patient is unconscious or otherwise unable to communicate, and it is necessary for an orderly, nurse or physician to check information on the identification bracelet against the patient's chart to be certain of identification.
The present invention is directed to a form of identification bracelet which is adapted to carry, in addition to the usual written or printed matter, a pictorial likeness of the patient. Thus, positive patient identification becomes a matter of little more than comparing the appearance of the patient with the likeness on the bracelet and, perhaps, an identical likeness affixed to the patient's chart.
Accordingly, it is an object of this invention to provide a novel identification bracelet, capable of carrying a pictorial likeness of the wearer. It is another object to provide a disposable hospital identification bracelet which is simple to manufacture and use. Other objects will appear hereinafter.
The foregoing and other objects of this invention are realized, in a presently preferred embodiment, by an identification bracelet in which a band portion is adapted to encircle a limb of a wearer to secure the bracelet to the limb; clasp means are associated with the band portion for securing the bracelet; and an enclosure, integrally formed with the band portion, has an outwardly facing transparent portion through which the likeness is visible. Thus, a likeness may be placed in the enclosure and seen through the transparent portion of the enclosure. A closure member is provided for the enclosure, preferably integrally molded with the band portion and hingedly attached to it, and the cover member is so positioned and arranged that it can fold beneath the band to cover the underside of the enclosure. Snap-engaging means associated with the cover member and enclosure also serve to secure the cover member in its enclosure-covering position.
For the purpose of illustrating the invention, there is shown in the drawings a form of the invention which is best mode presently contemplated, it being understood, however, that the invention is not limited to the precise arrangement and instrumentalities shown.
DESCRIPTION OF DRAWINGS
FIG. 1 is a perspective view of an identification bracelet in accordance with the present invention, in its initial, non-operative condition.
FIG. 2 is a cross-sectional view, taken along the line 2--2 in FIG. 1, but showing the invention in preparation for usage.
FIG. 3 is a cross-sectional view taken along the line 3--3 in FIG. 2.
FIG. 4 is a cross-sectional view taken along the line 4--4 in FIG. 2.
DETAILED DESCRIPTION
Referring now to the drawings in detail, wherein like reference numerals indicate like elements, there is seen in FIG. 1 an identification bracelet designated generally by the reference numeral 10.
The identification bracelet 10 comprises a band portion 12 adapted to circle a limb of a wearer to secure the bracelet 10 thereto. It will be appreciated that the bracelet 10 will ordinarily be placed around the wrist of a wearer, but it may, if necessary or desired, be applied elsewhere.
Clasp means are provided in association with the band portion 12 to facilitate closing of the band portion to form a continuous limb-encircling bracelet.
Referring now to FIGS. 1 and 2, the clasp means in the illustrated form of the invention comprises a guide portion 14 disposed adjacent one end of the band portion 12, an abutment 16 associted with the guide portion 14, and a series of ratchet members 18 associated with and disposed upon the other end of the band portion 12.
Referring now to FIG. 2, the manner in which the clasp means operates to secure the band portion 12 should now be apparent. The end of the band portion 12 which bears the ratchet members 18, it will be seen, may be threaded through the guide portion 14. The ratchet members 18 are so configured in profile that movement through the guide portion 14 in a band-tighting direction (indicated by the arrow "A" in FIG. 2) is facilitated. If, on the other hand, an effort is made to withdraw the end of the band portion 12 from the guide portion 14, a perpendicular surface 20 of a ratchet member 18 engages the abutment 16, and prevents loosening of the hand portion 12. Although it may be made removable if so desired for particular applications, it is preferable, and greatly to be desired in the usual case, that the identification bracelet 10 not be removable except by severing of the band portion 12.
Referring now to FIGS. 1 through 4, associated with the band portion 12 is an enclosure 22, which facilitates coupling to the band portion 12 of a pictorial likeness of the wearer. The enclosure 22 includes a transparent portion 24, which, when the bracelet 10 is operatively disposed, faces outwardly away from the limb of the wearer.
The underside of the enclosure 22 is open, but a closure member 26, associated with the band portion 12 and enclosure 22 in a manner which will be described below, serves to close and seal the underside of the enclosure 22 when the closure member 26 is operatively disposed.
Referring again to FIGS. 1 and 4, the closure member 26, in the illustrated form of the invention, is operatively associated with the enclosure 22 by means of a self-hinge 28, which enables the closure member 26 to rotate through an arc of approximately 180 degrees from its open, inoperative position illustrated in FIG. 1, to the operative position seen in cross-section in FIGS. 2 and 4.
Referring now to FIGS. 1, 2 and 4, the edges 30 of the closure member 26 in the illustrated embodiment are chamfered at an angle of approximately 30 degrees (30), and the chamfered edges 30 are associated, when the closure member 26 is operatively disposed, with a complimental chamfer 32 encircling the rear of the enclosure 22. The chamfered edges 30 and 32, it will be understood, provide a snap-engaging action, which causes the closure member 26 to securely and sealingly engage the rear of the enclosure 22 to close the enclosure 22. Closing of the closure member 26 serves to secure within the enclosure 22 a photograph 34 or other pictorial likeness of the wearer. The likeness, it will be appreciated, is oriented so that it can be viewed through the transparent portion 24 of the enclosure 22.
The orientation of the closure member 26 with respect to the limb of the wearer, when the bracelet 10 is operatively disposed, is such that the disposition of the rear of the closure member 26 with respect to the limb prevents the closure member 26 from inadvertently opening. Indeed, if the band portion 12 is suitably snug in its engagement with the limb of the wearer, opening of the enclosure 22 while the bracelet 10 is in position may be virtually impossible. The snap-engaging action of the closure member 26 and the enclosure 22 and the above mentioned disposition of the closure member 26 with respect to the limb of the wearer compliment each other, and together assure against inadvertent opening of the enclosure 22 and loss or removal of the photograph or other likeness.
Disposed within the band portion 12 of the identification bracelet 10 in a presently preferred embodiment is an elongated enclosure 36, which has a transparent portion 38 like the transparent portion 24 of the above-described enclosure 22. The enclosure 36 is adapted to receive and retain the usual and presently conventional written identifying indicia 39. The enclosure 36 is also provided with a closure member, designated by the reference numeral 40. The closure member 40 is coupled to the band portion 12 by a self-hinge 42, and like the closure member 26, the closure member 40 may be provided with chamfered edges 44 to compliment similarly chamfered edges 46 of the enclosure 36.
In its preferred embodiment, the identification bracelet 10 is molded in a single piece, perhaps most advantageously by injection molding techniques, from a clear material such as the tough, resilient semi-rigid and highly transparent polymer sold under the trademark "Surlyn" by E. I. du Pont de Nemours Co. Other suitable materials will occur to those skilled in the art. If desired, the surface texture of the bracelet 10 may be made rough so as to render the material translucent, except where transparency is desired, as at the transparent portions 24 and 38.
The present invention may be embodied in other specific forms without departing from its spirit or essential attributes, and, accordingly, reference should be made to the appended claims rather than the foregoing specification as indicating the scope of the invention.
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An identification bracelet has a band portion and an enclosure for a likeness of the wearer having an outwardly facing transparent portion, and a closure member adapted for snap closing of the enclosure. A second enclosure is provided for other identifying indicia. The enclosures and closure members are preferably integrally molded with the band portion.
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This application is a continuation-in-part of application Ser. No. 493,759 which was filed on Mar. 15, 1990 and which has now been abandoned.
BACKGROUND OF THE DISCLOSURE
The present disclosure is directed to a diaper for incontinent dogs, both male and female. Moreover, it is adapted for use with older dogs which have become messy because of age. Alternately, it can be used with younger dogs which are momentarily afflicted with various ailments, all for a short interval until the dog reestablishes control and does not mess or soil the immediate vicinity.
As long as people live in congregated areas, and as long as they keep pets, it is axiomatic that people will keep dogs in the house, mostly indoors for city dwellers. In contrast with an outdoor dog, such as one that stays at the barn or in the pasture, a house bound dog runs the risk of messing the interior area, and this is particularly true of older or sick dogs.
Newborn puppies typically are house broken after just a few weeks and a pleasant state of affairs is established with the owner. As the dog becomes older and the family attachment becomes stronger, sometimes the dog loses its control much to the upset and chagrin of the family, especially where the dog normally stays indoors. This is particularly a problem with older dogs, but it is also a momentary problem with dogs that are being medically treated, perhaps recovering from an ailment, injury or the like. Suffice it to say, incontinence and loss of control in general whether occasioned by old age, injury or ailment creates a problem for a house kept dog and the dog owner.
The present disclosure sets forth a kind of diaper which is intended for use with the dog. In particular, it is constructed in the form of an elongate pad having corner located tabs. There are four tabs, and they extend parallel to one another from opposite edges of the pad. The four tabs thereby enable the user to install the diaper on the house pet with a view of reducing consequences, that is, reducing the mess occasioned by loss of control of the older or sick dog. In this instance, it is particular helpful so that the difficulties resulting therefrom, whether permanent or temporary, can be reduced, and hopefully eliminated.
The present disclosure is a disposable diaper readily affixable to a dog. It is constructed in the form of an elongate pad. One particular feature is an opening or hole cut into the pad. The tail hole is sealed by a waterproof strip containing openings through which the tail is positioned. A strip of this nature provides a better seal around the dog's tail than would a mere hole or other opening, enhancing the ability of the diaper to prevent leakage caused by activity or movement of the animal.
Additionally, use of the strip provides better protection on a greater variety of dogs. For a particular size of the present apparatus, a device which can be scaled for larger or smaller dogs, there is some variety in tail dimensions including the diameter of the base of the tail, and the relative position of the tail on the dog, i.e. whether the tail is relatively high or low on the hind quarters. Additionally, the angle of deflection is different for each animal, meaning some dog's tails are carried high (e.g., a Beagle) while others point downward. In either case, the present apparatus is installed by sliding the tail through an opening provided in the strip, registering the diaper on the dog. Due to the various placement of the tail on the animal, the use of such a diaper provides greater latitude in the positioning of the diaper around the animal while still maintaining an effective seal.
The pad is wrapped in a U-shaped fashion around the body of the dog, partly over the top and partly below the hind quarters, thereby aligning the four tabs, two of the tabs on top and two on the bottom in corresponding positions on the left and the right of the animal. The tabs are easily attached to their opposing tabs by adhesive strips, thereby fixing the diaper to the dog. Removal is easily accomplished by simply peeling off the adhesive strips joining the tabs, thereby permitting diaper removal.
The present apparatus is a throw-away diaper which can then be discarded. It is constructed with multiple plies of material which may be biodegradable. The outer or exposed ply is a waterproof strength ply. The intermediate ply is an absorbent ply which preferably extends close to and parallel to the edges but it need not extend completely to the edges of the outer ply. The third ply is equal in area and similar in shape to the outer waterproof ply and it has edges that correspond the the outer ply. The third or inside ply is particularly provided for strength to hold the diaper together even when wet, but is sufficiently porous to enable the absorbent middle ply to accomplish its intended purpose.
While the foregoing summarizes the structure of the present disclosure, details of its construction and its mode of use or installation are set forth below with the description of the preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings.
It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
FIG. 1 shows a diaper in accordance with the teachings of the present disclosure which is constructed with an elongate pad which extends outwardly into four tabs at the corners thereof, and the four tabs aligned so that the diaper can be affixed to a dog. The diaper further includes an opening for the tail which is defined between two opposing adhesive planar sheets, with the strips containing slits the protrusion of the animal's tail;
FIG. 2 is a sectional view through the diaper of FIG. 1 along the line 2--2 and showing the layered construction of the three plies of material; and
FIG. 3 is a detailed sectional view along the line 3--3 of FIG. 1 showing the seams joining the outer and inner layers at a border.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Attention is now directed to FIG. 1 of the drawings where the diaper 10 of the present disclosure is shown. This view shows the shape of the diaper and includes features important to its successful use. As will be understood, the diaper 10 can be scaled to different sizes for large or small dogs. It is believed that the description given hereinafter will suffice for a representative size, and it can be scaled from that size to other sizes. The diaper 10 will be described as a planar member, it being understood that the diaper is folded and placed on the dog in the fashion set forth below. In addition, a description will be given of the constituent layers of the diaper. The diaper 10 has a pad region 12. The pad region is located below a tail hole 14. The tail hole is spaced from another region 16 which will be described as the back strap. This is a strap that fits in the fashion of an inverted U on the back of the dog and which is located forward of the tail and which extends against left and right ribs of the dog forward of the hind quarters. The back strap 16 is sufficiently long at the dimension 18 that it extends approximately fifty to seventy percent around the girth of the dog. The location is preferably about even with the kidneys or over the ribs of the dog. It need not stretch up to the chest region. The dimension 18 terminates at the left tab 20 and there is a symmetrical or right tab 22. As shown in the drawings, the entire structure is symmetrical along a centerline vertically through FIG. 1.
The tabs 20 and 22 are of equal width. The tail opening 14 is offset from the tabs 20 and 22 by a distance which accommodates the position of the tail on the body of the dog. Surprisingly, there is a good deal of variety between dogs of comparable weight or size. The variety arises in part with breeds, and this is manifest by the positioning of the tail on the body, relatively speaking. Moreover, the angle and size of the tail may vary. For that reason, a relatively long rectangle 14 is cut so that it will coincide with the region of the tail. To prevent leakage through the tail hole 14 and to provide a wider range of diaper placement, the tail hole 14 is marginally sealed with two adhesive strips which border the tail hole through which the tail is placed. This permits the tail to protrude through the tail hole 14 with some clearance while still maintaining an effective seal. It is also useful as a type of alignment or locator mark on the diaper. In other words, when the tab 20 and 22 and central portion 16 are positioned on the dog forward of the tail, diaper location is somewhat limited by the position of the diaper referenced to the tail of the dog.
The dimension 24 of the diaper 10 is preferably equal in length to the dimension 18. It terminates at left and right tabs 26 and 28. These tabs also are approximately equal in length to the tabs 20 and 22. The tabs 26 and 28 are positioned opposite the tabs 20 and 22 respectively. Thus, the tab 20 will be located on the left side of the dog extending from above the dog while the tab 26 is positioned on the left side of the dog extending upwardly from below. The dimension 24 is folded into a U-shape which positions the tabs 26 and 28 so they can reach up the sides of the dog approximately even with the tabs 20 and 22. This locates the tabs 26 and 28 approximately even with the kidneys or even with the rib cage. All four tabs are located forward of the hind quarters. The tabs 26 and 28 fold up and over the ends of the tabs 20 and 22. The dimensions 18 and 24, preferably equal, provide sufficient surplus length that the two tabs overlapping on the left and the two overlapping on the right can be fastened together. As a generalization, the dimensions 18 and 24 are preferably equal, and the sum of these two dimensions is greater than the circumference of the dog. This permits some overlap at the tabs.
The tabs are positioned one over the other, i.e., the tab 26 overlays the tab 20, or in reverse fashion. The tabs are thus joined when they overlap. To this end, short adhesive tabs 30 and 32 of suitable length are also included, and they adhere on the exposed exterior waterproof surface of the diaper 10. These tabs are preferably supplied with the adhesive on the adhesive tapes 30 and 32 folded so that the adhesive side adheres at a location out of the way and so that the tabs 30 and 32 can be extended to lap over the opposing tabs 20 and 22 thereby anchoring the diaper on the dog. The tab 30 is extended from the stored and folded position, and then it is lapped over the tab 20 and adheres to that tab. The same is accomplished on the other side.
Going to FIG. 2 of the drawings, it will be observed that the diaper 10 is formed of three plies of material. First of all, there is an outer ply 34 which is a waterproof thin layer. It is typically in the range of about one to four mils thick and is preferably a thin sheet plastic which is waterproof. It is fairly strong and resists tearing. In addition to that, there is another surface layer on the opposite side. These two layers hold therebetween an absorbent layer 36. The layer 36 is formed of multiple plies of absorbent material. It is woven or felted in the fashion of mesh or the like. Moreover, the absorbent pad forms a fairly thick sandwich between the outer layers, the layer 36 having an uncompressed thickness of up to about one centimeter. The absorbent layer need not have the width of the exposed surface layer 34. Therefore, the layer 36 is only slightly smaller in dimensions. The exposed surface ply 38 is opposite the outer surface ply 34. The layer 38 is relatively thin and yet it is porous. It is porous so that moisture can be absorbed into the absorbent ply therebetween. The ply 38 is therefore highly porous and able to admit moisture. It is, however, still somewhat strong. It is about the same in thickness as the layer 34. The layer 38 is preferably formed of an elastomeric material which is similar to the elastomeric material used in the surface layer 34.
The layers 34 and 38 join at the common edges around the periphery and at the hole 14. There, one method of joinder is machine stitching or, preferably, they are heat bonded into a common beaded seam. This defines the seam so that it is complete, there being a seam all the way around the opening 14.
In order to maintain a superior seal around the tail of the dog while maintaining a greater range of possible tail position and animal size, the tail hole 14 is sealed within two adhesive strips 42 and 44. The exterior strip 42 is a thin waterproof adhesive strip positioned as shown, completely covering the tail hole 14 and maintaining sufficient contact with the outer sheet 34 to provide adequate adherence. The interior adhesive strip 44 is a thin porous adhesive strip positioned as on the opposite face, completely covering the tail hole 14 and maintaining sufficient contact with the inner sheet 38 to provide adequate adherence. The two strips contact each other in the hole and are cut away to leave marginal edges or beads around the hole where the two strips seal adhesively.
DESCRIPTION OF THE PREFERRED MATERIALS
The layer 36 is absorbent layer which is intended to hold moisture. It is a biodegradable product of Weyerhaeuser which is approximately 88% biodegradable and is primarily formed of wood fluff pulp and related tissue which is primarily cellulose and also may include a cornstarch filled cover. The layers 34 and 38 are sheet material, typically of about one mill thickness. An important feature of the present construction is the mode in which the tail opening is formed. Briefly, the layers 34, 36, and 38 are cut with a rectangular opening of a certain size. Using a conventional die cutter, a rectangular hole is cut. More importantly, the thin sheet film members 34 and 38 are cut to a certain dimension, but, because of the felting of the innermost layer 36, it tends to cut and tear away so that the opening punched through the layer 36 is slightly larger than the opening in the layers 34 and 38. After that, the large opening is patched by adhering an outside film strip to the layer 34 and an external film strip to the layer 38. The inside layer 38 is closed by sealing it with a strip of surgical tape bearing the trademark "Micropore", which is a product of the Three M firm. It is a porous tape which permits the free passage of air and moisture through the tape. The tape is porous to air and moisture vapor transmission. In the descriptive literature regarding this product, the tape is formed with a synthetic polymeric acrylate adhesive which has a backing typically formed of rayon fibers yielding a product which is approximately 0.005 inches thick. This is shown at 42 in FIG. 1 of the drawings.
On the exterior face of the diaper, a similar, preferably equal strip is affixed to cover over the opening previously formed in the layers 34, 26, and 38. This is a layer of tape from the same Three M firm and bears the model number 2185 matte white film tape. The tape has a white matte finish on a polypropylene film with an adhesive. A rubber tacky adhesive is preferred. The thickness is approximately about 4 mils. The two strips of material are coextensive in area. They cover over and marginally adhere to the respective layers around the rectangular hole. In FIG. 1 of the drawings, this marginal region of adherence is illustrated. Thus, the rectangular openings in the layers 34 and 38 are identified by the hidden lines 46, while the adhesive margin 48 identifies the area where the layers 42 and 44 adhere to the areas which they contact. The two strips of film thus join as shown at one edge of the tail hole as shown in FIG. 3. That is, FIG. 3 shows how the strips 42 and 44 join to the body of the diaper surrounding the cut opening and extend into that opening and adhere to each other on the interior of the strip borders at 48. This forms a sealed seam. Preferably, the two strips 42 and 44 are stamped with a cutting die which forms an opening in the two of them, this die being somewhat smaller than the hidden cut line at 46 which is made by a larger die. This inner edge is identified at 50. The difference in dimensions is relatively small but is sufficient to permit marginal contact of the two strips 42 and 44 to thereby complete a closure or seam around the tail opening 14. The tail hole has a width B equal to about 40 to 60% of the strips 42 and 44.
As can be seen, fabrication is quite easy and straight forward. The first step is to cut through the layers 34, 36, and 38 by means of rectangular die cutting apparatus. Precautions are made to cut the absorbent layer 36 at the line 52 so that it is cut to form a hole having a larger dimension and the edge is back and out of the way. The next step is to adhere the two rectangular adhesive patches 42 and 44 so that they are closely aligned with each other and the two join to close over and seal the opening. Then, the third step is carried out, namely cutting a smaller rectangular opening through the two strips, leaving an encircling margin so that they join. This forms a seam at 50 closing the marginal edge or gap into the absorbent layer 36. This seam is leak proof. This seam is closed by this mode of manufacture. It provides a highly reinforced tail opening which will not tear at the relative narrow width of the diaper as shown in FIG. 1. The completed product can be successful sized to several sizes and fitted on a dog in the manner of operation as described below.
In operation, the device of the present disclosure is installed on an appropriately sized dog. The diaper can be made to size for the smallest and the largest dogs. For a particular sized dog, and one on which the dimensions are properly selected, the device is placed on the dog in the following fashion. The dog's tail is threaded through the opening and centered in the tail hole 14. The tabs 20 and 22 are pulled over the back of the dog so that the diaper 10 extends along the back of the dog for some distance and the tabs 20 and 22 are folded downward. They are deployed on opposite sides of the dog adjacent either the kidneys or the ribs. At the same instant, the reminder of the diaper is installed by folding the entire diaper downward, and then extending it forwardly of the dog so that the tabs 26 and 28 can be folded upwardly in front of the hind quarters of the dog. The tabs 26 and 28 align with tabs 20 and 22. The four tabs are positioned, two on the right and two on the left. When so positioned, the adhesive tabs 30 and 32 are unfolded and extended so that they adhere to the tabs 20 and 22 above. The tabs thus position the absorbent pad 36 within the diaper so that it is practically impossible for the dogs to form an untidy mess. The diaper is strategically placed on the dog so that soiling of the domestic area is prevented. Accordingly, this apparatus is particularly helpful in cleanliness where the dog has the run of the place.
While the foregoing is directed to the preferred embodiment, the scope thereof is determined by the claims which follow.
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A canine diaper is set forth and is comprised of three sheets of material. The outer sheet is a thin flexible waterproof sheet, the next sheet is an absorbent pad of multi-plyed construction, and the inner sheet is porous, and the diaper is shaped with a central tail hole in a strip which extends from the tail above and below the body terminating in four tabs which reach adjacent the ribs for fastening by adhesive strips.
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This application claims the benefit of U.S. Provisional Application No. 60/296,666, filed on Jun. 7, 2001.
FIELD OF THE INVENTION
The field of this invention is packers or plugs which undergo large expansions to set, such as through tubing, followed by setting in casing or open hole.
BACKGROUND OF THE INVENTION
In through tubing and open hole applications, annular seals are required which have large radial expansion capabilities. For mechanically set elements, the larger the required radial expansion, the more serious the problem of element extrusion under high differential pressure loads. Extrusion would occur beyond the end rings placed there to control that condition. Various designs for backup rings have been tried with only limited success with the exception being where the extrusion gap around such rings is kept to a minimum. This situation usually involved a traditional casing packer application. Prior designs, in large expansion applications have allowed a gap to exist, which has been sufficiently large to allow extrusion to occur.
Another problem plaguing prior designs of mechanically set packers has been the inability to get a proper set over the length of the element. This happened because element would be pushed from a first end and start to set from that end. If the end near where the setting force was being applied engaged the casing or the open hole, further pushing would not allow the balance of the element to be firmly pressed against the casing or borehole.
The preferred embodiment of the present invention addresses these shortcomings of the past designs. It has a mechanism for setting from the end opposite of where the pushing force is being applied. Because of this, very long elements can be reliably mechanically set. The sealing element assembly includes a composite structure, which effectively closes the extrusion gap regardless of the large expansion. While the preferred embodiment accomplishes these objectives, the scope of the invention is far broader as will be explained in detail below and illustrated in the claims.
Of interest with regard to prior designs are U.S. Pat. Nos. 2,132,723; 2.254,060; 2,660,247; 2,699214; 2,738,013; 2,738,014; 2,738,015; 3,392,785; 3,784,214; 4,258,926; 5,775,429; 5,904,354; and 5,941,313. Of more interest among this group of patents is U.S. Pat. No. 5,941,313. It discloses using deformable sheaths surrounding a material placed therein. This structure is taught for service as a main seal or a backup member to the seal but not both. The sheath is a thin walled tubular member formed from a metallic or other material having sufficient strength and elasticity to bend without fracturing. In some embodiments, a resilient material is overlaid on the sheath but no provisions are made to keep this layer from extruding upon set. In another embodiment, exterior deformation surfaces interact with the sheath to redirect its deformation. No explanation is offered as to how pushing on the sheath at a second end results in initial deformation of the sheath against the exterior deformation surface adjacent the first end.
Testing by applicants has shown that one major concern with pressure set elements is that the element portions closer to where the element is being pushed expand first. This has the potential of weakening the grip of the remaining portions of the element. The present invention overcomes this problem by temporarily stiffening the end being pushed on to allow the remainder of the sealing element to contact the casing or the well bore. Thereafter, with the remote part of the element against a firm support, the proximate portion of the element is forced into sealing contact, overcoming the temporary stiffening. The invention encompasses a variety of ways to accomplish this objective and to prevent or minimize extrusion after the set.
SUMMARY OF THE INVENTION
A packing element, which is a composite structure, is disclosed. Components contain the sealing portion to minimize extrusion. The element is retained in tension when running in to minimize damage. In the preferred embodiment, a collapsing sleeve transfers setting force applied at one end, to the opposite end to avoid the problem of bunching up the element adjacent to where it is being compressed which could, if not addressed, result in insufficiently low sealing contact pressure in regions remote from where the pushing force is applied.
DETAILED DESCRIPTION OF THE DRAWINGS
FIG. 1 is an outer view, partly in section, showing the innermost components adjacent to the mandrel;
FIG. 2 is the view of FIG. 1 showing the internal sealing element:
FIG. 3 is the view of FIG. 2 showing the layers above the internal sealing element:
FIG. 4 is the view of FIG. 3 showing the outer sealing element that makes contact with the casing, tubular or borehole.
FIG. 5 is a run in view of the assembly in part section;
FIG. 6 is the view of FIG. 5 in the set position;
FIG. 7 is a section view along lines 7 — 7 of FIG. 5 ;
FIG. 8 is a section view along lines 8 — 8 of FIG. 5 ;
FIG. 9 is a section view along lines 9 — 9 of FIG. 5 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 and 2 the mandrel 10 has a top thread 12 and a bottom thread 14 to allow running into a well. It further comprises a stationary sleeve 16 and a movable sleeve 18 . Sleeve 18 may be actuated in an up-hole direction by known techniques such as use of wellbore hydrostatic pressure against an atmospheric chamber or applied mechanical or hydraulic pressure or combinations of the above. On top of the mandrel 10 are a pair of collapsing sleeves 20 which preferably have openings 22 to selectively weaken them. In between the sleeves 20 is a spacer 24 , which preferably distributes what would be essentially a line contact between ends of sleeves 20 if they were stacked end to end. The spacer 24 can have opposing female receptacles to allow ends of adjacent sleeves 20 to be inserted so they can be guided and held in alignment as a force is applied to movable sleeve 18 . The reasons for using sleeves 20 can be better understood by examining FIGS. 1 and 2 together. As shown in FIG. 2 , the internal sealing element 26 spans over sleeves 20 and spacer 24 as it extends between stationary sleeve 16 and movable sleeve 18 . It also covers a seal ring 28 , which has an internal o-ring 30 for the purpose of internal sealing along the mandrel 10 . The problem addressed by sleeves 20 is that when movable sleeve 18 is set in up-hole motion, the element 26 , in the absence of sleeves 20 will tend to bunch up and contact the casing or wellbore at end 32 rather than uniformly along its length or more preferably from the up-hole end 34 . Expansion initially at end 32 is not desirable because it can prevent sufficient contact pressure from reaching the up-hole end 34 for a proper seal.
The present invention seeks to direct the pushing force from movable sleeve 18 through a mechanism other than the seal 26 for a predetermined portion of its length. Sleeves 20 have sufficient structural rigidity to redirect the pushing force from movable sleeve 18 to the up-hole segment 34 of the sealing element 26 such that the up-hole segment expands first into contact with the casing, tubular or wellbore. After sufficient contact pressure develops, further pushing by movable sleeve 18 collapses one or both sleeves 20 to allow the pushing force from movable sleeve 18 to go into the lower end 32 of the seal 26 and push it out into sealing contact in the manner just accomplished for up-hole segment 34 . The openings 22 are designed to allow sleeves 20 to buckle after up-hole segment 34 is in sealing contact, at which point, in the preferred embodiment they serve no further significant structural purpose. Sealing force on the lower segment 32 of the seal 26 is principally determined by the pushing force into the resilient lower segment 32 after the upper segment has set. Those skilled in the art can appreciate that one or more sleeves can be uses and that each sleeve can be in round or other cross-sectional shape. The column strength of multiple sleeves or even of a single sleeve 20 can vary along its length, by a variety of techniques. The opening, pattern, number, or size can be varied and/or the wall thickness can change along the length. Different materials can be used along the length. The objective of the various combinations described is to have sufficient aggregate column strength to transfer initial expansion by compression of seal 26 to its upper segment 34 first, through the sleeve or sleeves 20 . It is then preferred that after buckling. The sleeves 20 play a minimal part in the compression of the remainder of seal 26 , while recognizing that the mere presence of the collapsed sleeve 20 in the lower end 32 will, by its mere presence distribute some pushing force from movable sleeve 18 to lower end 32 . It should also be noted that sleeve or sleeves 20 could be complete cylinders, with or without a seam or sheet turned into a cylindrical shape or other shape by scrolling. Sleeves 20 can have longitudinal corrugations as another technique for adjusting their column strength. Instead of sleeves, other structures that have column strength to a point and then will buckle can be used to get the desired movement of seal 26 as described above. Some examples are stacked beveled washers, springs, rods and similar elongated structures that ultimately collapse, bend or deform under load. Also envisioned are materials whose properties can change in response to various fields or currents applied to them. Also envisioned is a variability on the hardness of seal 26 acting in conjunction with sleeves 20 to allow for segment 34 being less resistant to expansion so it will make sealing contact first and the balance getting progressively or suddenly stiffer or harder to promote the desired direction of expansion from up-hole segment 34 to downhole segment 32 of seal 26 .
Apart from the problem of not getting enough contact pressure for a good seal, there is another potential problem that is addressed by the present invention. That problem is element extrusion through end gaps after setting. The solution of the preferred embodiment is shown in FIGS. 3 and 4 . FIG. 3 illustrates the use of tubes 36 and 38 , which extend respectively from sleeves 16 and 18 and can be seen in the section view at the top of FIG. 3 . Tubes 36 and 38 preferably do not cover the length of seal 26 leaving a gap 40 in between. The preferred material is a continuous-aramid, Kevlar or carbon fiber, tube that is mechanically secured at sleeves 16 and 18 . Tubes 36 and 38 are preferably constructed of braided fibers to facilitate radial expansion of not only seal 26 but also of outer seal 42 (FIG. 4 ), which is mounted in a recess 44 ( FIG. 2 ) of seal 26 . In the preferred embodiment, the recess 44 is centrally mounted but offset locations can also be used. The recess 44 is optional but its use facilitates the resistance to extrusion after set, as will be explained below. The seal 26 can preferably be a solid rubber mass or segments or a particle material. A particle material offers an added advantage of being able to move freely during the setting operation and a greater ability to conform to irregularities in the shape of the wellbore. The use of tubes 36 and 38 further makes particle materials such as rubber useful because the rubber is elastic and can store energy, which is contained by tubes 36 and 38 . These strong tubes are a significant element in keeping the seal 26 from extruding past sleeves 16 or 18 . Tubes 36 and 38 can be used alone or can be reinforced with overlaying tube segments 37 (see FIG. 7 ), secured to sleeves 16 and 18 . Such reinforcing tubes can be of the same material or fiberglass matte or woven metal mesh. They would provide additional resistance to extrusion in an area where the mechanical stresses are the greatest.
Another feature is the use of a tube 46 , which extends from sleeve 16 to sleeve 18 and is securely attached to both. It is preferably a reinforced steel mesh sleeve which provides support for the element 42 when set because it expands into contact with the casing, tubular or wellbore above and below element 42 , thus acting as an extrusion barrier for it. The actual main sealing occurs along the length of element 42 in contact with the wellbore, tubular, or casing. During run in, tube 46 keeps seal 26 in tension to reduce its profile and protects it from abrasion as it is run into the well. Additionally, as the depth increases the additional hydrostatic force applied to an unbalanced piston area in a hydrostatic setting mechanism, helps to keep the seal 26 taut. The use of a recess 44 to mount the seal 42 insures that portions of the tube 46 expand into contact with the wellbore, casing or tubular both above and below seal 42 and preferably in contact with it on both ends to prevent extrusion and, to a lesser extent, apply an additional sealing force.
Optionally, a barrier material 48 having some lubricity can be applied over tube 46 but under seal 42 . The preferred material is PTFE and its presence keeps the seal 42 from bonding to seal 26 through tube 46 . Other materials such as a mold release can also be used. The objective is to keep adjacent seal components from bonding to each other. If the material further promotes sliding, due to its lubricating qualities, then its performance is even better. As previously stated, tubes 36 and 38 leave a gap 40 in between and the barrier material, preferably in the form of tape can span that gap 40 , thus keeping rubber from seal 42 from bonding to seal 26 at gap 40 . The presence of the barrier material 48 allows seal 46 to move into uniform contact with the surrounding environment without kinking or binding.
Those skilled in the art will appreciate that the packing element described above insures proper expansion of the underlying or fill material of seal 26 beginning at the end furthest from where the expansion force is being applied. This is accomplished by channeling the applied force to the remote end by a force transfer mechanism such as sleeves 20 . The force transfer mechanism, by design, is overcome after the upper segment 34 is firmly against a surrounding surface to allow the balance of the seal 26 at its lower segment 32 to complete the expansion. While that is going on tubes 36 and 38 and any backup tubes guard against extrusion. The outer seal 42 can expand against the surrounding surface and be surrounded above and below by portions of the mesh tube 46 . For additional protection against extrusion, the ends of the sleeves 16 and 18 can have longitudinal splits giving the effect of long fingers. These fingers 50 are spread against the surrounding space to give an added extrusion barrier. They can be held together initially for run in so as to keep them out of the way. Additionally, tube 46 keeps the run in profile low as well as serving as an extrusion barrier to both seal 26 and outer seal 42 .
The above description is representative of the preferred embodiment and the various modifications and alterations that can be made within the scope of the invention are clearly defined below in the appended claims:
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A packing element, which is a composite structure, contains the sealing portion to minimize extrusion. The element is retained in tension when running in to minimize damage. In the preferred embodiment, a collapsing sleeve transfers setting force applied at one end, to the opposite end to avoid the problem of bunching up the element adjacent to where it is being compressed which could, if not addressed, result in insufficiently low sealing contact pressure in regions remote from where the pushing force is applied.
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[0001] This nonprovisional application claims priority to German Patent Application No. DE 10 2013 223 066.4, which was filed in Germany on Nov. 13, 2013, and which is herein incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a thermally driven condenser unit and an adsorption heat or refrigeration plant.
[0004] 2. Description of the Background Art
[0005] WO 2007/068481 A1, which corresponds to U.S. Pat. No. 8,806,883, which is incorporated herein by reference, describes an adsorption heat pump, having a plurality of hollow elements, each having an adsorption-desorption region and an evaporation-condensation region, i.e., a phase change region. The hollow elements have a heat transport fluid flowing through them in each of these regions, with cyclic changes by means of valve arrangements in the interconnection of the hollow elements with regard to the fluid flow. The plurality of hollow elements to be filled with a working medium may have the disadvantage of a high cost of installation.
[0006] WO 2013/011102 A1, which corresponds to US 20140223955, and which describes a concept of a sorption module, in which tube bundles arranged in a shared housing are arranged for transfer of the adsorption-desorption heat to an adsorber structure on the one hand and heat of condensation and evaporation to a phase change structure on the other hand, wherein the housing concept comprise a supporting structure which accommodates the pressure difference between the external atmospheric pressure and the vacuum prevailing in the working medium space.
[0007] A disadvantage in the conventional art is that in desorption of working media from the sorption zone, a portion of the working medium is condensed in cool locations of the housing wall and thereby lost for the subsequent evaporation. This lost condensate additionally cools the housing wall in re-evaporation, causing a cold surface in the next partial cycle with renewed condensation so that unwanted faulty condensation takes place there again. This is associated with a loss of power and efficiency. In addition, the possibility cannot be ruled out that in automotive applications, larger amounts of working media already condensed may be lost due to spillage because of vibration of the housing wall. Another disadvantage is the complex construction of the sorption module, the manufacture of which requires expensive tools.
[0008] One disadvantage of sorption modules known in the past having an integrated condensation and evaporation structure is the storage of refrigeration which has not previously been implemented. This requires an externally controllable fluid cutoff option between the condensation structure and the evaporation structure. Although this is a given with known approaches having separate condensers, nonreturn valves for the desorbed vapor are required for this purpose and must have an opening pressure, which is subject to loss, and a sufficient cross section for the vapor density of the working medium.
SUMMARY OF THE INVENTION
[0009] It is therefore an object of the present invention to provide a thermally driven condenser unit and an adsorption heat or refrigeration plant in which all the heat of condensation is made available for optional heating purposes and the amount of condensate for subsequent evaporation is made available to withdraw heat from a low temperature heat source and adsorption heat and/or evaporation refrigeration can optionally be stored almost without any loss.
[0010] An exemplary embodiment relates to a thermally driven condenser unit with a thermal compressor wherein the thermal compressor forms a modular component with a condenser. This modular thermally driven condenser unit combines the thermal compression of working media and the condensation in one module.
[0011] The thermal compressor advantageously has a housing which forms a fluid-tight working medium space in its interior, in which the thermal compressor designed as a sorption heat exchanger is arranged, and the sorption heat exchanger is connected to a first fluid guidance system, which is in turn connected thermally to an adsorber structure, the condenser being formed by a jacket, which surrounds the housing on the outside and has a second fluid guidance system for guiding the coolant and absorbing heat of condensation during a desorption phase of the adsorber structure. Due to the combination of a sorption heat exchanger with a thermally activated housing wall, all the loss mechanisms attributable to foreign condensation and subsequent evaporation of foreign media are prevented, so that the performance and efficiency of the heat pump or refrigeration system having this design are increased.
[0012] In an embodiment, the housing can be designed to be approximately cylindrical and is sealed at the bottom with a condensate collecting device that protrudes above the housing, thereby connecting a condensate drain line having a first nonreturn valve. Because of the cylindrical shape of the housing and of the jacket surrounding the housing, the condensate that is formed flows by gravity down the inside of the jacket, which is positioned largely vertically, and is collected by the condensate collecting device. The condensate collecting device may be designed here as a channel that is open at the top or as a ring channel. The condensate can then be drained out of the thermally driven condenser unit by means of the first nonreturn valve.
[0013] In a variant, the first nonreturn valve in the cross section and/or opening pressure can be designed so that a liquid working medium can pass through with a negligible pressure. In this context, “negligible” can mean that the saturation temperature of the liquid working medium drops only by few degrees Kelvin, for example, less than 5K, in passing through the first nonreturn valve. In the presence of gaseous working media, the valve cross section limits the volume flow due to the vapor pressure, which is reduced significantly. This first nonreturn valve thus functions as a supercooling control element.
[0014] In an embodiment, the condensate collecting device can be designed as a collecting channel having a gradient to the condensate drain line. This ensures that the condensate will run out of the thermally driven condenser unit without requiring any additional auxiliary component for conveyance of the condensate.
[0015] Alternatively, however, a pressure different may also be built up for displacement of the condensate by actively or passively cooling the liquid collector connected thereto. The saturated steam pressure of the condensate stored in the liquid collector is kept below the condensation pressure so that the condensate is drawn out of the condensate collection device even without auxiliary aids and, if necessary, also against the force of gravity, overcoming the opening pressure of the nonreturn valve.
[0016] In the following adsorption process, the nonreturn valve prevents the working medium from flowing back out of the liquid collector into the thermal compressor.
[0017] The nonreturn valve on the high pressure side may be designed to be much smaller and thus less expensive, which is advantageous in particular for the use of water as a working medium with its great density difference between liquid and gaseous phases.
[0018] A suction line connection designed with a second nonreturn valve can be arranged on the housing for suction intake of gaseous working medium. By means of this suction line connection, the working medium vapor is drawn in from an evaporator at the evaporation pressure level, for example, and then adsorbed in the adsorber structure with dissipation of the heat of adsorption. In the subsequent desorption and condensation with a pressure level that has been raised accordingly, this second nonreturn valve prevents the working medium vapor from being forced back into the evaporator.
[0019] In an embodiment, an intermediate space between the jacket and the housing has coolant flowing through it continuously in parallel to the axis of the cylindrical housing. Therefore, no fluid controller is necessary, which simplifies the dissipation of condensation heat.
[0020] In an embodiment, an inside surface of the jacket and/or of the condensate collecting device can be designed, so that only a small amount of liquid working medium remains in the working medium space when there is a pressure change between a condensation pressure and an evaporator pressure. This can be achieved by a geodetic arrangement of the functional components, for example, without requiring any additional aids.
[0021] A refinement of the invention relates to an adsorption heat or refrigeration plant, having at least one thermally driven condenser unit. In an adsorption heat or refrigeration plant, which may be designed as an adsorption heat pump or as an adsorption heat storage device and/or refrigerant storage device, the total condensation heat is thus available for optional heating purposes as well as the amount of condensation heat being available for the subsequent evaporation for removal of heat from a low temperature heat source when the condenser unit is designed according to the embodiments herein. In such a system, any number of condenser units may be installed and combined in an adsorption heat or refrigeration plant, so that the power and the storage capacity of the adsorption heat or refrigeration plant, for example a heat pump, can be easily adapted to existing requirements.
[0022] In one variant the at least one condenser unit can be connected to an evaporator unit, i.e., a condenserless unit, by means of a liquid line and a suction vapor line, wherein the evaporator unit combines in another module a liquid collector, an electrically controllable expansion valve and an evaporator for cooling a fluid in another module. For fluid connection of a plurality of condenser units, there are several possibilities to permit either high power densities or high COP values with efficient heat recovery. The condenser unit can be combined with various embodiments of an evaporator unit. Thus, for example, the evaporator may be used for cooling a coolant or may also be used for direct cooling of air.
[0023] Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] 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 limitive of the present invention, and wherein:
[0025] FIG. 1 shows an exemplary embodiment of a thermally driven condenser unit,
[0026] FIG. 2 shows an exemplary embodiment of a jacketed tube of the condenser unit according to the invention, as shown in FIG. 1 ,
[0027] FIG. 3 shows an exemplary embodiment of a jacketed tube of a liquefier wet according to FIG. 1 ,
[0028] FIG. 4 shows an exemplary embodiment of the tube bundle of a sorption heat exchanger,
[0029] FIG. 5 shows an exemplary embodiment of a thermally driven condenser unit,
[0030] FIG. 6 shows an exemplary embodiment of an adsorption heat pump and/or a refrigeration and heat storage device.
DETAILED DESCRIPTION
[0031] FIG. 1 shows an exemplary embodiment of the thermally driven condenser unit according to the invention. This condenser unit 1 is designed as a module having a housing 2 , which forms a fluid-tight working medium space 3 in its interior. A sorption heat exchanger 4 , which has fluid connections 5 , 6 , is arranged inside the working medium space 3 . A fluid guidance system, which is in thermal contact with another adsorber structure (not shown), is formed by the fluid connections 5 , 6 . The sorption heat exchanger 4 may have a heating medium of varying temperature flowing through it by means of the at least one inlet 5 and the at least one outlet 6 of the fluid guidance system, resulting in thermal cycling of the adsorber structure. A pressure alternation within the working medium space 3 is caused by the resulting desorption and adsorption of the working medium.
[0032] The housing 2 , which is designed to be cylindrical, is surrounded by a jacket 7 on the outside, which may be of any desired shape, but in the present case is also designed to be cylindrical according to the cylindrical housing 2 and, together with the latter, forms a fluid-tight intermediate space 13 , through which fluid can flow. This is part of a second fluid guidance system which adsorbs the heat of condensation resulting from the flow of a coolant during the desorption phase of the adsorber structure on the inside wall of the housing 2 and thereby limits the pressure of the working medium during the desorption phase to the condensation pressure. The housing 2 has a condensate collecting device 8 on the inside of the lower end of the jacketed region. This condensate collecting device 8 is preferably designed as an annular channel for holding the condensate because the condensate that is formed runs down the inside of the housing 2 , which is preferably designed to be vertical, and is collected by the condensate collecting device 8 . The condensate is drained out of the condenser unit 1 to the outside through a condensate drain line 9 which has a nonreturn valve 10 . In addition, a suction line connection 12 having a second nonreturn valve 11 is arranged on the housing 2 for suction intake of working medium vapor.
[0033] The cross section and opening pressure of the nonreturn valve 10 , which is provided on the condensate collection device 8 , is designed to allow a liquid working medium to pass through with a negligible pressure drop. “Negligible” can mean that the saturation temperature in passing through the nonreturn valve drops by only a few degrees Kelvin, preferably less than 5K. In the presence of gaseous working media, the valve cross section limits the volume flow because of the much lower vapor density. This nonreturn valve thus functions as a supercooling control element, which is similar to an orifice that has very little throttling and is known from compression refrigeration technology.
[0034] An intermediate space 13 between the jacket 7 and the housing 2 is supplied with a condensation heat medium, which is introduced into the intermediate space 13 through a condensation heat medium inlet 14 situated at the top of the housing 2 and is discharged from the intermediate space 13 through a condensation heat medium outlet 15 formed diagonally on the opposite side of the jacket 7 . The condensation heat medium thus flows through the condenser unit 1 , from top to bottom in the present embodiment, essentially parallel to the cylindrical housing 2 .
[0035] The walls of the jacket 7 of the condenser unit 1 have flow through them constantly in parallel for dissipation of the heat of condensation without a fluid controller. In addition, the internal surface of the housing 2 and/or of the condensate collecting device 8 is designed so that in the event of a pressure change between the condensation pressure and the evaporation pressure only a negligible amount of liquid working medium or none at all remains in the working medium space 3 and the condensate collecting device 8 , which is achieved by a geodetic arrangement of the functional components for example. This is achieved through the structuring and/or coating of the inside of the housing 2 and the condensate collecting device 8 .
[0036] FIGS. 2 and 3 show embodiments of a jacketed tube 16 and 17 , respectively, which combine both the housing 2 and the jacket 7 at the same time and form a structural unit. Each jacketed tube 16 , 17 is formed of a simple, preferably cylindrical, metal tube, which tapers at one end 18 and widens at its other end 19 . This jacketed tube 16 , 17 may also be equipped with one or more peripheral ring or spiral grooves, for example, in an IHU or circulating process to allow a change in longitudinal expansion and to ensure stabilization of the peripheral shape, preferably circular.
[0037] FIG. 2 shows the inner jacketed tube 20 , preferably made of steel or stainless steel and having at least one flat tube coil 21 coiled around it, connected to the outer jacketed tube 22 with a heat-conducting connection, e.g., by means of a heat-conducting adhesive. The embodiment according to FIG. 2 combines components that are available inexpensively in the form of a stainless steel tube, which has been reshaped only slightly, preferably as a cylindrical housing jacket, having a multichamber flat tube, which can be made of extruded aluminum, for example, and shaped into a flat tube coil 21 . Other embodiments of this basic principle of the combination of at tube coil with a jacketed tube are also conceivable.
[0038] In the exemplary embodiment of the jacketed tube 17 according to FIG. 3 , an annular gap 23 through which coolant can flow is formed with another exterior jacketed tube 22 having a matching diameter at the end, forming an annular gap with the interior jacketed tube 20 . This annular gap 23 may be equipped with spacers (not shown) such as webs, nubs, beading or folds, preferably created by shaping techniques, to create a defined through-flow and stabilization of the cross section, which is preferably circular. The interior and exterior jacketed tubes 20 , 22 are physically bonded together preferably by welding, in particular laser welding, on at least one end. Spacers (not shown further) can also ensure that a defined forced flow is induced through the annular gap 23 with particularly homogeneous thermal regulation of the jacketed tube 17 . A spiral flow similar to that of the embodiment according to FIG. 2 is particularly advantageous.
[0039] The lateral surfaces of the jacketed tubes 21 , 22 , which are thermally activated by means of fluid flow agents, in addition to dissipating the heat of condensation from the wall of the jacket, also serve at the same time to stabilize the preferably circular cross section, which is particularly stable with respect to varying pressure differences between the inside and outside.
[0040] The second embodiment according to FIG. 3 , having two cylinders inserted one into the other, produces an even more direct thermal contact between the coolant and the lateral surface of the interior jacketed tube 20 by eliminating the adhesive layer and the thickness of one tube wall.
[0041] For closure of the end faces of the jacketed tubes 16 , 17 of the working medium space 3 , deep-drawn or otherwise shaped metallic tube sheets 25 , 27 may be used, wherein fluid passages to the interior sorption heat exchanger 24 are provided on at least one tube sheet 25 , 27 . A preferred exemplary embodiment of such a sorption heat exchanger 24 is shown in FIG. 4 . The tube bundle 26 can be connected with a vacuum-tight seal to two differently shaped tube sheets 25 and 27 by a physically bonded joining technique such as laser welding at one end. The tube sheets 25 , 27 are of such dimensions that the entire submodule of the cassetted tube bundle 26 is inserted into the jacketed tube 16 and/or 17 and connected to it for a vacuum-tight housing. To do so, the smaller tube sheet 25 is adapted to the diameter of the tapered end 18 of the jacketed tube 16 , and the larger tube sheet 27 is adapted to the diameter of the widened end 19 of the jacketed tube 16 . As shown in FIG. 4 , the smaller tube sheet 25 has a higher edge, which, in the condition of being joined to the jacketed tube 16 and/or 17 , results in formation the annular channel 8 between the jacketed tube 16 and/or 17 and the tube sheet 25 . With a vertical position of the cylindrical condenser unit 1 , the condensate running down the inside wall of the jacketed tube 16 is collected and can be drained to the outside through the condensate drain line 9 and the first nonreturn valve 10 arranged therein.
[0042] FIG. 5 shows the assembly of the condenser unit described here, which is supplemented with water tanks 28 , 29 to complete the sorption heat exchanger 24 , these water tanks being connected to the tube sheets 25 , 27 in a fluid-tight connection on the outside with a seal and with techniques that are not explained further here.
[0043] In this embodiment, the condensate collecting device 8 can be decoupled thermally from the sorption heat exchanger 4 due to the distance between the regions 8 and 29 , which are thermally regulated at different temperatures, to minimize a harmful heat flow from the sorption heat exchanger 4 to the condensation region 23 and the condensate collecting device 8 .
[0044] The diagram on the right shows again the internal jacketed tube 20 , which is tapered or widened in steps at the end for gap-free accommodation of the tube sheets 25 , 27 according to FIG. 4 . The tubes of the tube bundles 26 have an adsorber structure on the outside, which has good thermal contact but is not shown here further and can be cycled thermally between two temperature limits by means of a thermally regulated heating medium, which is variable over time. To accommodate differences in thermomechanical expansion and/or stresses, the tube sheets 25 , 27 are embodied as so-called diaphragm sheets and/or cylinder jackets having an expansion beading.
[0045] The components described here work as thermally driven condenser unit 1 in which an alternation in pressure from evaporation pressure to condensation pressure is implemented first. This takes place by having the heating medium flow through the sorption heat exchanger 24 at a progressively higher temperature. Due to the associated increase in pressure, the second nonreturn valve 11 on the intake end closes first.
[0046] Additionally, the task of desorption and condensation is fulfilled by the condenser unit 1 . This takes place in that the sorption heat exchanger 24 has further flow through it by means of a hot heating medium wherein working medium is desorbed at a high pressure. The high pressure keeps the nonreturn valve 11 on the intake end closed. The working medium condenses on the cooled wall of the internal jacketed tube 20 and runs down the wall into the annular channel 8 described above, where it exits from the working medium space 3 through a nonreturn valve 10 designed for the liquid phase and preferably enters a liquid collector (not shown here). When the collecting device is empty, an additional outflow of working medium vapor into the actively or passively cooled liquid collector is largely prevented, so that the condensation pressure and the liquid supercooling are regulated at levels close to the boiling point.
[0047] In addition, the components described here permit a pressure alternation of condensation pressure to vapor pressure. To do so, the temperature of the heating medium flowing through the sorption heat exchanger 24 is reduced progressively. Due to the associated pressure reduction, the condensation comes to a standstill and the nonreturn valve 10 on the fluid end closes. On reaching the evaporation pressure, the second nonreturn valve 11 in the intake line 12 opens.
[0048] As an additional function of the condenser unit, the vapor suction and adsorption are performed. The sorption heat exchanger 4 , 24 has additional flow through it by means of the recooled heat exchanger, wherein working medium evaporated in an evaporator is drawn in and absorbed at a low pressure.
[0049] The condenser unit described here is a module, which can be combined with any number of other condenser units. Based on the thermally driven condenser unit 1 shown here, a modular thermally driven heat pump or a refrigeration plant with optionally combined heat and/or refrigeration storage function can be constructed as follows. In the present case, three condenser units 1 are connected to the liquid collector 30 in FIG. 6 . This number may be varied, however, depending on the application case. This liquid collector 30 is connected to an evaporator 32 via an expansion valve 31 that can be cut off and/or pulse width modulated, the suction line 33 of the evaporator being connected to the suction connection 34 of the three condenser units 1 . In the present variant, the evaporator 32 has air flowing through it by means of a fan 35 . Alternatively, however, the evaporator 32 may also be embodied as a condenser.
[0050] The components which complete the thermally driven condenser unit 1 thus include the liquid collector 30 , the electrically controllable, preferably pulse-width-modulated expansion valve 31 and the evaporator 32 for cooling a fluid. The plant presented here, which is arranged between a heat sink 36 and heat source 37 , fulfills various functions. The plant may be used for heating purposes, for example, as a thermally driven heat pump. A fuel heater, a caloric device or the like, for example, may be used for high-temperature heat. The heat sink 36 represents the object to be heated for example a building, a room or a vehicle cab, where the heat of adsorption and the heat of condensation are emitted at a moderate temperature level. Low-temperature heat from the environment for example from the outside air, from a ground probe or a solar collector is observed in the evaporator 32 .
[0051] In addition, use as a thermally driven refrigeration plant is also possible. Waste heat or excess heat from any processes or plants or heat from a fuel heater is then used as the high temperature heat. The environment is used as the heat sink, where the adsorption heat and condensation heat are dissipated. Low temperature heat is absorbed directly or indirectly in the evaporator from an object or a room to be cooled, thereby cooling the later.
[0052] In addition, use as an adsorption heat or refrigeration storage mechanism is also possible. When the externally controllable expansion valve 31 is closed, refrigeration energy can be accumulated and stored by desorbing one or more condenser unit modules and storing the resulting condensate in a liquid collector 30 , which is designed with a capacity of such dimensions that it can hold the total amount of working medium of all condenser units 1 . Then at least one, preferably all, of the condenser units are brought to the temperature of recooling, so that determination of a high refrigeration power is prepared. When there is a demand for refrigeration, the expansion valve 31 is opened or is cycled in the pulse width modulation method so that the desired evaporation power is released. Due to the working medium vapor taken in by the modules and adsorbed, these modules heat up and release adsorption heat which can then be used to preheat a motor or the like for example. Before discharge of the stored heat and refrigeration energy, desorption of the first condenser unit 1 may be initiated to adjust the steady-state refrigeration power.
[0053] 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 to be included within the scope of the following claims.
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A thermally driven condenser unit and an adsorption heat plant constructed therewith, which can be used as an adsorption heat pump, adsorption refrigeration plant, heat store and/or refrigeration storage mechanism. The thermally driven condenser unit integrates a thermal compressor and a condenser in a modular component.
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BACKGROUND OF THE INVENTION
1. FIELD OF THE INVENTION
The present invention relates to load frames and in more particularly to means for reacting side loads between the upper and lower cross heads or platens of a load frame.
2. PRIOR ART
In the prior art, the assignee of the present invention, MTS Systems Corporation of Eden Prairie, Minnesota has been engaged in making and selling various multiple column load frames for various uses.
For example, the corporation is the owner of U.S. Pat. No. 3,442,120 which shows a resonant hydraulic fatigue testing device utilizing a load frame with upright columns, wherein suitable hydraulic clamps can be used on the smooth columns (or other types of clamps if desired). Such clamps are conventionally used and have been used for many years.
Heavy load frames having four columns, one on each of the corners of a square or rectilinear base, and having a movable cross head mounted on the columns have also been widely used.
The columns used between the platens adequately carry the vertical loads (parallel to the axes of the columns), and are capable of reacting side loads caused by specimen misalignment. Typical side load capability for load frames is less than ten percent of the axial load. Stress and deflection of the columns in horizontal direction (assuming that the columns are vertical) can thus be a problem when testing specimens that require substantial biaxial loading.
SUMMARY OF THE INVENTION
The present invention relates to a load frame comprising a support member or base platen with columns fixed to the base and extending from said base in a first direction. A second cross head or platen is mounted on the columns and is capable of having its spacing adjusted relative to the base, and wherein the assembly includes a diagonally extending brace or strut member extending from adjacent one edge of one of the platens, and diagonally upward to a position adjacent an opposite edge of the same side of the platens. The brace is capable of being clamped relative to the other platen. The diagonal brace thus is oriented to carry loads perpendicular to the axis of the support columns.
These braces or struts will be positioned to the exterior of the platens, and can be detachably secured on at least one end to permit moving them out of the way for putting specimens into the load frame if desired. The clamps that are utilized with the braces permit adjusting the platens relative to each other, as well as adequate clamping. Different types of braces can be used, and various mounting pin configurations and clamp devices can be utilized.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of a load frame having a diagonal brace made according to the present invention installed thereon;
FIG. 2 is a sectional view taken generally along line 2--1 in FIG. 1;
FIG. 3 is a sectional view taken as on line 3--3 in FIG. 2;
FIG. 4 is a sectional view taken as on line 4--4 in FIG. 1;
FIG. 5 is a side elevational schematic representation of a load frame substantially identical to that shown in FIG. 1 with a modified diagonal brace made according to the present invention installed thereon; and
FIG. 6 is a sectional view taken as on line 6--6 in FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 a typical load frame illustrated generally at 10 is shown in a side elevational view only, and is shown only schematically. The load frame that is shown is square when viewed in plan or top view, and has four columns on at each corner of the square frame. Two of the columns indicated at 11,11 are mounted to a base platen 12, and a cross head or platen 13 is slidably mounted on these columns. Again, it should be remembered that the columns 11,11 are spaced in square configuration and are shown only schematically for purposes of illustration in this showing.
The platen 13 is movably mounted on the columns 11,11 and can be slid along the columns and then clamped into position at a location spaced from the base platen 12. This is common in load frames, and the means of clamping onto the columns 11,11 is also well known. For schematic illustrative purposes only, the adjustment of the upper platen 13 can be accomplished through the use of a long hydraulic cylinder assembly illustrated generally at 15 that is attached to a support 16 on the base platen 12, and is also attached to a support 17 on the movable platen 13. The cylinder 15 is shown only in one corner of the load frame, but there would be a separate cylinder mounted at each of the corners for raising and lowering the upper platen 13. Other ways of raising and lowering the platen can be employed, if desired.
The upper platen 13 may be clamped onto the individual columns 11 through the use of clamping cylinders indicated generally at 20 in the corner on the left hand side, and these clamping cylinders are conventionally used in load frames made by MTS Systems Corporation, Eden Prairie, Minn. The cylinders and clamping action is generally shown in FIG. 4 in connection with the clamping of the diagonal brace of the present invention, and on the corners where the braces are not used individual clamping cylinders 20,20 are used, as shown.
The ability to react biaxial loads, that is loads which have components along and perpendicular to the columns 11 is greatly increased through the use of a diagonal brace indicated generally at 21. As shown, there is a brace on the near side of the load frame, and there would be an identical brace on the opposite side of the frame which can extend in the same direction as that shown by the brace 21.
The brace 21 in the form shown is a flat bar, although the brace can be a round rod if desired, and as shown in FIGS. 5 and 6. One end of the brace 21 is pivotally mounted onto a suitable pin 22 that is fixed to the base 12. In the first form shown, a pivot pin is illustrated, but it also could be a clamp connection. For example, the hub indicated at 23 could be split and clamped with a suitable hydraulic cylinder so that once the upper platen 13 was fixed in position, and the diagonal brace 21 was also fixed at its upper end, as will be explained, the hub 23 could be clamped to the pin 22 to prevent any backlash or movement. Further, pin 22 is illustrated in the drawings as carrying loads along a single shear plane, but a support for the pin on the outside or near side of the hub 23 also can be provided to carry the load on the pin along two shear planes.
The brace 21 extends diagonally as shown toward an upper corner 24 of the platen 13. As can be seen in FIGS. 2, 3 and 4 the brace 21 engages a pivotally or rotatably mounted disc member 25 that is recessed into a suitable round recess 26 on one side of the platen 13. The disc will pivot or rotate in this recess. The brace 21 also as shown is provided with splines or teeth 27 that engage mating splines 28 in the disc 25. The two sets of splines slide relative to each other when the position of the two platens 12 and 13 is varied. The function of the spline teeth is to increase the friction coefficient of this joint (the increase is inversely proportional to the sine of the pressure angle). Various other techniques may be used to increase the friction coefficient or efficiency of this clamp joint.
The edge portion of platen 13 as shown in FIG. 4 may be split to fit around the column 11. The brace 21 is to the exterior of the platen 13. In order to clamp the platen 13 to the column 11 (as is conventionally done) and also to tightly clamp the diagonal brace 21, a clamp block 30 is mounted on the exterior of the brace 21. The clamp block 30 carries suitable hydraulic clamping cylinders 31, which may be constructed substantially identically to those shown at 20,20. The cylinders 31 have an internal piston indicated at 32 in FIG. 2. The pistons in turn are carried on pistion rods 33 that may be suitably threaded into or attached to platen 13, as indicated at 34 in dotted lines.
Hydraulic fluid pressure can be supplied to suitable conduits 35 that lead to the rod sides of the pistons 32, and when pressure is supplied through the conduits 35 the block 30 will be urged toward the platen 13. The hydraulic cylinders will clamp the diagonal brace 21 against the disc 25, and likewise then will clamp the disc 25 against the surfaces of the platen to tightly frictionally hold the brace 21 clamped in position and also hold the platen clamped on column 11. If the hub 23 also has a clamp on pin 22, it would then be clamped once the platens are positioned, so that no backlash or looseness is permitted and any side loads that would tend to bend the columns 11, would be reacted back through the diagonal brace 21 as well as through the columns 11. There would then be little or no bending of the columns.
As stated previously, if it is desired to place a test device in the space between the platens 12 and 13, and the brace 21 is in the way (there likely will be braces or struts on all four sides of the frame) the pin 22 can be removed, or the hub 23 could be released in a desired manner, and the lower end of brace 21 lifted upwardly. The disc 25 would pivot as the hub end 23 was lifted, with the upper clamp cylinders released. A winch or block and tackle can be used to lift the brace 21.
It should be noted that the platens 12 and 13 are fixed in position on the columns 11, and loading would be done through suitable load cylinders indicated schematically at 40 and 41. These cylinders can be arranged in any desired location over the platen 12 to carry out the test that is desired. In particular, the type of load frame utilized can be one where, for example mine roof supports shown schematically at 42 were being tested, and the structure forming the roof supports would be placed between the platens 12 and 13 and tested. The supports could be loaded up vertically using cylinders 40 and horizontally using cylinders 41 in order to simulate both vertical and horizontal slippage in the mine roof. The showing is schematic for purposes of illustration.
Use of the cylinders 31 for clamping both the upper end of the diagonal strut or brace and clamping that particular corner of the platen 13 to the columns 11 minimizes the additional cost and yet provides adequate clamping for both the platen and the strut itself. In this case, horizontal capacity is a ratio of vertical capacity determined by friction coefficients of the joints. Alternatively, use of a pin at each end of the diagonal strut with an independent clamp device built into the strut that allows adjustment of the strut length, as will now be explained, permits independent selection of force capacities for each structural member.
In FIGS. 5 and 6 a modified form of the brace or strut is illustrated. The load frame is the same as that shown in 10, and corresponding parts are labeled with corresponding numbers. Biaxial loading (horizontal and vertical) is provided in the device of FIG. 5 as well, and as shown in FIG. 5, the upper platen 13 is raised and lowered relative to the lower or base platen 12 through the use of two hydraulic cylinders 15. The cylinders 15 provide a balanced load on the upper platen as it is moved along the upright columns 11.
The modified diagonal brace illustrated generally at 40 as shown comprises a lower sleeve or housing member 41, and a telescoping upper shaft or strut member 42. The lower member is pivotally mounted onto a pin 43 in a suitable manner to the base platen 12, and the strut of shaft member 42 is pivotally mounted with a pin 44 at its upper end to the upper platen 13. The member 42 telescopes into a provided receptacle indicated in dotted lines at 41A in the sleeve member 41. Rod 42 will telescope into the receptacle in a normal manner. The upper portions of the sleeve member 41 are split, as can be seen at 41B in FIG. 6, and this split permits clamping and releasing of the member 42 to either prevent or permit sliding movement of the member 42 relative to sleeve 41 and platen 12 by tightening the outer sleeve 41 down onto the strut member 42 through the use of a pair of hydraulic cylinders indicated at 45.
The cylinders 45 are constructed the same as the cylinders 31, and each has a piston 46 that actuates a rod 47 that as shown is threadably mounted into one section of the housing member 41, and is slidably mounted through other portions of the housing so that piston rod 47 spans the split or recess 41. When pressure is introduced into the interior of the cylinders 45 through a conduit connection 48, the pressure will act on the bottom side of the respective pistons 46 and will exert a force tending to clamp the housing 41 onto the strut or rod 42.
Two such cylinder assemblies 45 are utilized to insure secure clamping. The piston can be readily released from pressure to permit telescoping of rod 42 and sleeve 41 to in turn permit movement of the upper platen 13 when desired.
As shown in the dotted line position 44A of the upper end portion of the rod member 42, the rod and sleeve assembly will telescope a substantial distance to accommodate a wide variety of different positions of the platen.
The diagonal brace 40 can be utilized at all four sides of the load frame assembly, and also can be pivoted out of the way by removing either the pin 44 or the pin 43 and pivoting the brace on the other pin that is left in place to position clear of the space between the columns 11 to thereby permit insertion or removal of test apparatus.
In both forms of the invention a diagonal strut is provided which is releasably clamped relative to the platens to form a rigid load carrying member. In the first form of the invention the diagonal brace or strut could be releasably clamped at either end or at both ends. Also note that the members 25 and 30 slidably receive strut 21 and when clamped react loads between the strut and platens. The struts also could be pinned or otherwise held to prevent axial sliding movement relative to both platens.
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A load frame used for testing purposes which includes means for reacting side loads between upper and lower cross heads of platens of a press or load frame.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an encapsulation for a high voltage interrupter.
2. Description of Related Art
High voltage interrupters are typically mounted at the upper end of an epoxy or porcelain structure or encapsulation that includes an internal chamber for supporting the interrupter and operating rod.
The structure must be designed to prevent "tracking," i.e., charges from creeping along the surface of the wall of the structure from high potential to a frame which is at ground potential as a result of surface contamination condensing and building up on the surface. In addition, the structure must be designed to prevent a direct strike of charges between the interrupter and the base. As a general rule, the length of the surface necessary to prevent creep is longer than that needed to prevent a strike. Accordingly, the support structures are typically taller than necessary.
In addition, the base of an epoxy encapsulation is bolted to a frame or structure at the bottom end of the support. Typically threaded nuts are inserted into a mold prior to casting the epoxy encapsulation. The finished cast product then includes a plurality of nuts that can be used to bolt the encapsulation to a frame. However, on occasion, one or more nuts are omitted or put in at an incorrect angle, thus jeopardizing the final product strength. In addition, on occasion, uneven loading may cause the insert nuts to pull out, thus also weakening the strength of the structure.
OBJECTS AND SUMMARY
It is an object of the present invention to overcome the above-described disadvantages of the prior art by utilizing a design wherein tracking can be avoided without having to create a structure that is taller than necessary to overcome strikes.
It is a further object to provide a design that is simpler to construct than those of the prior art and provides increased strength.
The encapsulation for an interrupter, comprises a main body that includes an internal cavity; said internal cavity including a space at a first end thereof for the interrupter; said internal cavity including an internal wall extending from the interrupter space to a second end of the encapsulation; means at the second end of the encapsulation for mounting the encapsulation; and said internal wall including a convolution. The internal wall includes a plurality of concentric skirts arranged in an overlapping manner.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view of an interrupter encapsulation according to the present invention;
FIG. 2 is an illustration of a mechanical stress analysis of a portion of the encapsulation of FIG. 1;
FIG. 3 illustrates a voltage distribution inside the encapsulation of FIG. 1;
FIG. 4 illustrates an electric field distribution inside the encapsulation of FIG. 1;
FIG. 5 is a side view of an insert assembly that is used in the encapsulation of FIG. 1;
FIG. 6 is a plan view of the insert assembly of FIG. 5;
FIG. 7 illustrates a voltage distribution round the insert assembly of FIG. 5;
FIG. 8 illustrates an electric field around the insert assembly of FIG. 5; and
FIG. 9 illustrates a cross-section of an alternative embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning attention to FIG. 1, an encapsulation or support 10 for an interrupter 12 is illustrated. The encapsulation 10 includes an internal chamber 14, through which an operating rod (not shown) passes for connecting the interrupter 12 to an activating mechanism (not shown) in the frame 16 below the encapsulation 10.
The encapsulation 10 may be cast from epoxy, or any other suitable material capable of withstanding the stresses that occur during activation of the interrupter 12. In a preferred embodiment, cycloaliphatic prefilled hot-curing two-component epoxy resin is used to form the encapsulation.
If the distance between the interrupter 12 and the frame 16 is insufficient, a phenomenon known as striking may occur, in which a charge jumps from the interrupter 12 to the frame 16. Accordingly, the distance between the interrupter 12 and the frame 16 must be kept greater than a predetermined distance, i.e., the strike distance, depending upon the conditions and voltages at which the interrupter 12 is being used.
In addition, a charge may creep along the internal wall 18 or surface of the internal chamber 14. Accordingly, the length of the wall 18 should be kept greater than a certain distance to prevent creep. Typically the distance necessary to prevent creep is greater than the strike distance. Accordingly, in order to prevent creep, the prior art structures were designed taller than was necessary to prevent strikes.
According to the present invention, convolutions 20 are designed into the internal wall 18 in order to increase the overall length of the internal wall 18 so as to decrease the likelihood of creep. As a result of the increased length of the wall added by the convolutions 20, creep can be avoided without having to make the encapsulation 10 taller than is necessary to avoid strikes.
The convolutions 20 can be as wide and deep as molding and mechanical constraints allow. In a preferred embodiment, each convolution 20 is about one-half inch deep, adding about one inch of creep distance per convolution 20.
The convolutions 20 can be cast by inserting a ram or core into the internal chamber 14 during the casting process. By designing the walls 22 of the convolutions 20 substantially parallel to the internal wall 18 of the internal chamber 14, the ram can be easily inserted and withdrawn.
An additional benefit of the design of the internal chamber 14 is that, as a result of the convolutions 20, the internal wall is formed by a plurality of overlapping skirt-like sections 24. Thus, if moisture is trapped inside the internal chamber 14 should condense, resulting in water flowing down the wall 18, the water will drop from each of the convolutions 20, thus preventing a continuous stream of water that would contribute to tracking. In a sense, each of the skirts 24 acts as an umbrella to prevent the underlying skirts 24 from becoming wet.
In a preferred embodiment, the wall 18 of the chamber 14 includes two convolutions 20. Other quantities of convolutions 20 may be used depending on the particular application of the interrupter 12.
Alternatively, the increase of the overall wall length may be achieved during casting by the use of a threaded ram which may be withdrawn from the mold cavity subsequent to casting by rotating the ram to unscrew it from the casting. The thread 118 cast into the inner wall 18 may extend for more than 360° and may be one-half inch deep. FIG. 9 is a cross section of an encapsulation formed with a threaded ram.
FIG. 2 illustrates a mechanical stress analysis of a portion of the encapsulation 10 of FIG. 1. As illustrated in FIG. 2, the peak mechanical stress is about 5×10 5 N/m 2 when a cantilevered load of 25 pounds is applied to an end of an arm extending from the top of the encapsulation. The stress is well below the strength of the epoxy. Accordingly, the convolutions 20 do not compromise the strength of the encapsulation 10.
FIGS. 3 and 4 illustrate the electrical stress of the encapsulation 10. In particular, FIG. 3 illustrates the voltage distribution about the chamber 14. FIG. 4 illustrates the electric field (stress), i.e., the gradient voltage variation, of the chamber 14.
To support the encapsulation 10 and interrupter 12, threaded nuts 26 are insertted into the base of the encapsulation 10 during the casting process. Preferably, the nuts 26 are equally spaced in a circular pattern. Bolts (not shown) are then used to fasten the encapsulation 10 to the frame 16.
To facilitate assembly and to increase the strength of the finished product, the nuts 26 are prearranged on an insert assembly 28. The assembly 28 preferably includes a pair of rings 30, 32 concentrically arranged. See FIGS. 5 and 6. The threaded nuts 26 may be welded, or otherwise secured, to the rings 30, 32. In a preferred embodiment, eight nuts 26 are equally spaced at 45° between the concentric rings 30, 32. The approximate diameter of the insert assembly 28 is 4.6 inches.
The insert assembly 28 may be inserted into a mold prior to casting the encapsulation 10 so, as can be seen in FIG. 2, the stress values detected near the rings 30, 32 are relatively low.
FIG. 7 illustrates a voltage potential where an encapsulation 10, with the insert assembly 28, is bolted to a structure which also contains a high voltage potential. FIG. 8 illustrates the electric field (stress) around the rings 30, 32. As can be seen, the rings 30, 32 act to smooth out the electric field below its breakdown value.
Although only preferred embodiments are specifically illustrated and described herein, it will be appreciated that many modifications and variations of the present invention are possible in light of the above teachings and within the purview of the appended claims without departing from the spirit and intended scope of the invention.
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An encapsulation for an interrupter includes a main body that includes an internal cavity; the internal cavity including a space at a first end thereof for the interrupter; the internal cavity including an internal wall extending from the interrupter space to a second end of the encapsulation; a surface at the second end of the encapsulation for mounting the encapsulation; the internal wall including a convolution.
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BACKGROUND OF THE PRESENT INVENTION
1. Field of the Present Invention
The present invention relates to a technique for producing planar silicon on insulator MOS transistors, where the channel regions are created in an underlying single crystal silicon wafer, and where the source-drain extension regions are created by damascene patterning a thin film of amorphous silicon deposited on a layer of oxide deposited on the silicon wafer.
2. Description of the Prior Art
The primary advantage of using silicon on insulator (SOI) substrates, rather than using bulk silicon, for forming MOS transistors has long been recognized as being that of reduced stray capacitance. This allows, of course, higher operating frequencies to be obtained. SOI has other advantages such as better packing density, borderless contacts, latch-up freedom, and radiation hardness.
A thin film of crystalline silicon epitaxially deposited on a polished single crystal aluminum oxide substrate (SOS) was the first composite material to be used for SOI. However, since the crystal properties of aluminum oxide do not perfectly match those of silicon there has always been the problem of reduced yield due to defects in the silicon film.
In recent years SOI circuits have been made by forming a thin film of crystalline silicon on silicon dioxide, where the oxide has been grown on a silicon support wafer. This has enabled the production of silicon films with much lower defect densities, because the support wafer physical properties, such as thermal expansion coefficient, match those of the silicon film. Currently SOI refers to silicon on oxide, which will be our convention.
There are a few different methods for producing SOI substrates, such as wafer bonding or high current oxygen implantation. All of these methods are rather difficult because the silicon film has to be single crystal, and for best performance of the finished circuit, the film should be very thin (less than approximately 1000 Angstroms).
Another difficulty with current SOI is that the MOS transistor body connections are typically left floating for efficiency of chip layout. This can sometimes cause problems. For example, excess charge can remain in a transistor floating body region when attempting to turn a transistor off, which can slow down circuit operation. This problem can be solved by implanting just the right amount of recombination centers in the film; however, this is difficult to control, because too many centers will degrade the mobility of the film.
It is therefore the object of the present invention to provide a simplified method for producing SOI substrates; and to provide a technique for electrically connecting MOS body regions to well defined voltages without incurring any layout area penalty; and to maintain the high density layout capability of current SOI.
SUMMARY OF THE PRESENT INVENTION
The present invention is a technique for damascene patterning of silicon on insulator MOS transistors in a thin film of amorphous silicon deposited on a layer of oxide grown on a silicon wafer, where the oxide has previously been partially etched with a pattern of trenches, and where the amorphous silicon is chemically mechanically removed everywhere but in these trenches. In addition, the invention provides for the amorphous layer to contact the underlying silicon substrate through multiple small oxide openings, where subsequent transistor channel regions, aligned to these openings, will be formed in the underlying single crystal silicon wafer.
IN THE DRAWINGS
FIG. 1 is a cross section of a portion of a wafer at the beginning of this invention, where wells have been previously formed, where SiO 2 and Si 3 N 4 have been grown, and where photoresist has been patterned.
FIG. 2 shows a wafer after etching Si 3 N 4 , SiO 2 , and Si.
FIG. 3 shows a wafer after deposition of SiO 2 .
FIG. 4 shows a wafer after chemical mechanical polishing of SiO 2 , and after removal of the thin Si 3 N 4 and SiO 2 .
FIG. 5A shows a wafer after etching SiO 2 .
FIG. 5B shows a plan view after etching SiO 2 .
FIG. 6 shows a wafer after deposition of amorphous Si.
FIG. 7 shows a wafer after chemical mechanical polish of the amorphous Si.
FIG. 8 shows a cross section of an NMOS transistor, that uses this invention's starting material.
DETAILED DESCRIPTION OF THE INVENTION
The following is a description of a preferred process flow for making the SOI substrates of this invention, where the thicknesses shown are representative of the requirements for a low voltage CMOS logic circuit. Other thicknesses can used for different applications.
1. FIG. 1 shows, at the start of the process, a portion of a single crystal silicon wafer 1 that has a grown SiO 2 layer 3 with a thickness of ˜10 nm, a deposited Si 3 N 4 layer 4 with a thickness of ˜10 nm and shows patterned photoresist that will define the location of MOS channel regions. Also a previously implanted and diffused well region 2 is shown.
2. With the resist in place the wafer is etched to remove the thin Si 3 N 4 , the thin SiO 2 , and finally plasma etched to remove ˜300 nm of silicon. After resist removal silicon pedestals 5 will remain capped with thin oxide and nitride, as shown in FIG. 2 These silicon pedestals will be ˜300 nm high, and there will be one positioned for every MOS channel region in a subsequent logic circuit. To provide for alignment tolerance, the lateral length and width of each pedestal will be slightly larger than the subsequent MOS channel region to which the pedestal aligns.
3. After a good cleaning silicon dioxide 6 is deposited by well known techniques to a thickness greater than 300 nm. The results of this are shown in FIG. 3. As is well known, for the best quality the SiO 2 should be steam densified.
4. Next chemical mechanical polishing is performed on the SiO 2 using the Si 3 N 4 at the tops of the pedestals as etch stops. Next the thin oxide and nitride layers at the tops of the pedestals are removed, and finally a final smoothing chemical mechanical polishing is performed, with the pedestal silicon 5 as an etch stop. FIG. 4 shows the results of these steps, where the top of the deposited oxide is essentially coplanar with the tops of the pedestals, both being ˜300 nm high.
5. Next photoresist is patterned with openings 8 to define a complete MOS transistor, having source, drain and channel regions. Through these openings the deposited oxide is partially etched to a depth of ˜100 nm, using either a wet etch or plasma etch that etches oxide much faster than silicon. FIG. 5A shows the results of this after photoresist removal, where ˜300 nm of oxide 6 is left in what will become the field regions between MOS transistors, and ˜200 nm of oxide 7 is in the regions that will be beneath the source and drain extensions. FIG. 5B is a planar view of the same.
6. After a good cleaning, amorphous silicon 9 is deposited to a thickness >100 nm, which is shown in FIG. 6. In the same reactor hydrogen should be flowed over the wafers just prior to silicon deposition to remove any residual oxide that might remain on the tops or sides of the pedestals, thereby, assuring intimate contact between the pedestals and the deposited silicon.
7. The wafer is then chemical mechanically polished using the ˜300 nm field oxide as an etch stop, followed, if necessary, by a short polishing chemical mechanical etch to assure the top surface of the single crystal pedestals 5 are exposed. FIG. 7 shows the results of this polishing.
Subsequent processing can proceed using well known procedures. FIG. 8 shows the cross section of a completed silicon gate NMOS transistor that uses this invention's starting material. More complex transistors are possible, such as transistors with silicided gates or silicided source drain regions
The pedestal regions 5 are somewhat wider and longer than the transistor channel region. This is to insure, that even with some small misalignment, the transistor regions directly under the Poly gates will be directly over the silicon substrate.
All the Figures are not quite drawn to scale laterally; pedestals 5 typically will be less than 1/6 of the transistor areas defined by openings 8, resulting in most of the transistor area positioned over oxide rather than over silicon. This will reduce the capacitance of the source and drain junctions, and will allow source and drain contact openings to aluminum to be made with zero misalignment tolerance.
The process flow as described results in field regions between transistors having a thickness of 300 nm. Field regions of this thickness can have a very high field inversion voltage if the previously implanted and diffused wells have a diffusion profile that results in dopings of ˜10 18 ions/cm 3 approximately 300 nm below the original silicon wafer surface, because this depth becomes the final wafer oxide interface. High well doping levels will also prevent bulk punch through either from source to drain or between neighboring devices. Such a high well doping is not possible with older non SOI processes because source and drain junction capacitance would be prohibitive.
Even with high well doping levels between transistors, the doping level at the tops of pedestals, which are MOS channel regions, can be adjusted to be lower by adjusting the well implant profiles into the original wafers to be heavier ˜300 nm into the silicon, and much lighter at the silicon surface. It is also possible to dope channel regions with separate implants.
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The present invention is a technique for producing planar silicon on insulator MOS transistors, where the channel regions are created in an underlying single crystal silicon wafer, and where the source-drain extension regions are created by damascene patterning a thin film of amorphous silicon deposited on a layer of oxide deposited on the silicon wafer.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application No. 61/693,707, filed 27 Aug. 2012, which is incorporated by reference in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
This invention was made with Government support under Agreement/Contract Number DE-NT0000749, awarded by the United States Department of Energy. The Government has certain rights in the invention.
BACKGROUND OF THE INVENTION
1. Field of Invention
The invention relates to a multi-stage circulating fluidized bed (CFB) cooler for cooling a hot gas stream from a reactor while generating both saturated steam and superheated steam. More specifically, the invention is associated with a cooler for cooling the hot syngas from a gasifier handling carbonaceous materials such as coal, biomass or municipal wastes as feed, the cooler simultaneously generates high pressure saturated and superheated steam for power generation. The cooler agglomerates molten ash droplets that are typically present in the syngas generated from a slagging gasifier. The present multi-stage CFB syngas cooler also protects heat transfer surfaces from contacting other fouling, erosive and corrosive substances in the syngas produced by slagging and other types of gasifiers.
2. Background of Art
For those of skill in the art of syngas cooling, difficulties of cooling syngas when directly contacting syngas with the heat transfer surfaces are well-known, and include: plugging the gas flow path due to entrained substances in the syngas, fouling of the heat transfer surfaces due both to deposition of fine molten ash droplets and to tar components in the syngas, erosion due to fine ash and char entrained from the gasifier, and corrosion due to components in the syngas such as hydrogen sulfide and chloride.
Another difficulty associated with syngas cooling is identifying and handling materials of construction for heat transfer surfaces that are compatible with high temperatures and protecting relatively expensive heat transfer surfaces for reliable operation.
At present, options attempting to circumvent the many difficulties of reliably cooling syngas greatly sacrifice process efficiencies. For example, to stay within temperature limits of materials of construction of a conventional convective syngas cooler, the gasifier exit stream must be initially cooled by mixing with large amounts of relatively cooler recycle gas. Other examples of sacrificed process efficiencies in order to accommodate existing syngas coolers include upstream quench cooling, injecting coal in upper portions of the gasifier to lower gasifier exit temperatures, and operating the gasifier at lower temperatures with the attendant lower carbon conversion.
U.S. Pat. No. 8,197,564 discloses an example of quench cooling the syngas downstream of an entrained flow gasifier and radiant syngas cooler to limit downstream plugging and fouling problems normally associated with fine ash and slag that are separated from the gas stream either by precipitating or by surface cooling with direct contact with water. Such quench cooling systems involve an expensive radiant syngas cooler and less-than-reliable water treatment systems to separate particles and treat water as the spent quench water, which is highly corrosive and erosive in nature, increasing overall costs to cool the syngas. In addition, practical experience indicates that the combination of radiant and quench cooling of syngas is not completely effective in limiting (avoiding) plugging problems of a downstream convective cooler.
Syngas generated from fluidized bed gasifiers exits the gasifiers at relatively lower temperatures (approximately 1000° C.) as compared to entrained flow gasifiers. Even then, a syngas cooler to cool the syngas exiting such gasifiers is a relatively expensive piece of equipment due to the use of exotic alloys for the cooling tubes. In a conventional convective cooler that contact the syngas near 1000° C. under high pressure conditions such exotic and expensive alloys must be used. A further difficulty in cooling the syngas from fluidized bed gasifiers is the fine ash and char particles entrained therein that tend to erode the cooling tube surfaces. Deposition and fouling gradually degrades the cooling effectiveness and results in less than desirable superheated steam conditions, affecting generation capacity in an integrated gasification combined cycle (IGCC) plant. To deal with these difficulties and inlet syngas cooler conditions, thick-wall designs comprising exotic alloys have to be used for cooler heat transfer surface materials of construction.
Syngas coolers have limited cooling capacities due to internal hydrodynamics, pressure drop and other process considerations that limit its physical dimensions. In some applications such as in an IGCC process of a nominal 300 MWe capacity, cooling the syngas from a single gasifier requires multiple syngas coolers in parallel. Multiple, parallel syngas coolers in a process line inevitably increase both the costs and layout complexities in handling high pressure syngas near 1000° C.
Processing biomass and bituminous coals in some fluidized bed gasifiers lead to tar formation that entrains with the syngas as it exits the gasifier. The tar components deposit on syngas cooler heat transfer surfaces and downstream equipment and the deteriorating foul conditions eventually lead to an inoperable process. Similar difficulties are encountered while processing coals that contain higher percentage of alkali metals in coal minerals. Even at increased costs and overall decreases in process efficiencies, conventional syngas coolers still cannot be reliably used for these processes with known mitigating measures upstream.
U.S. Pat. No. 4,412,848 discloses a method to cool syngas in a two-stage fluidized bed cooling system. The first-stage fluidized bed cooler operates in the temperature range of 450-500° C. in an attempt to minimize tar condensation on the surface of the inert bed material particles. The second-stage cooler operates in the temperature range of 250-300° C. in an attempt to allow liquid condensation onto the particle surfaces. To avoid solidified condensate accumulation on the surface of the particles, oxygen and steam are injected into the second-stage cooler to burn off the condensate or char on the particle surfaces. This two-stage fluidized bed cooling system advances the art of syngas cooling compared with many other types of heat exchangers for similar applications when the syngas contains condensable liquids or char. It can also generate moderate temperature and high pressure steam to improve the overall process efficiency if the steam is used for power generation. Yet the '848 two-stage fluidized bed cooling system encounters practical difficulties.
One notable disadvantage relates to the substantial amount of oily matter contained in the syngas exiting the cooler that makes it difficult and expensive to treat the sour water that is generated from scrubbing the syngas downstream. Another serious issue is safety—as disclosed, the operating temperature of the second-stage cooler is substantially below the auto ignition temperatures of major components of the syngas such as carbon monoxide (609° C.), hydrogen (500° C.) and methane (580° C.). The operating temperature of 400-500° C. in the combustion zone of the second-stage cooler is lower than the auto ignition temperature of syngas components.
Those of skill in the art fully appreciate the danger or increased potential for explosion when injecting oxygen into a syngas stream whose temperature is below the auto ignition temperature. Beyond such safety concerns, the low temperature partial oxidation method necessitates a much larger space for the cooler for a combustion zone and generates much more CO 2 than CO.
The cooling capacity of the '848 cooler is also disadvantageous. In a bubbling or spouted bed cooler, the gas superficial velocity is generally below 1 meter per second (m/s). As a result, when large amounts of syngas from a typical IGCC plant needs to be cooled, at least two syngas coolers in parallel are required to avoid the cooler diameter from being above normal transportation limits. Yet parallel cooler arrangements are expensive because the syngas has to be routed to the coolers by refractory lined pipes.
U.S. Pat. No. 5,759,495 discloses a method and apparatus for treating hot gases including syngas in a circulating fluidized bed. It teaches that the gas is sufficiently cooled before it contacts the cooling surface, alleging that erosion of cooling surface in the riser will not be an issue. Yes this teaching oversimplifies a complicated issue. When the cooling surface is in the direct flow path of the riser, where gas superficial velocity is typically above 5 m/s, the erosion of even a cooler cooling surface is inevitable. It is therefore impractical to install the cooling surface inside the riser. Even if not implausible, operating the cooler at such low temperatures generates low grade steam, which is of much less use in a power plant environment. Furthermore, the '495 Patent is silent on how to handle the solids and/or liquid condensate accumulation on the cooler and particle surfaces.
Another internally circulating fluidized bed syngas cooler is disclosed in U.S. Patent Publication No. 2004/0100902. Beneficially, the gas superficial velocity in the disclosed cooler can be operated in the range of 5-10 m/s so that one cooler can handle up to a volume of 90 actual cubic meters per second (m 3 /s), which relates to a capacity larger than known commercial gasifiers. Although the teaching in this Publication can have wide applications for treating syngas, it too does not disclose how to avoid contaminant accumulations on the particle surfaces and regeneration of bed materials from such contaminants. Furthermore, the Publication discloses a single-stage cooler that does not address the steam conditions necessary for power generation.
To overcome the operability, efficiency and cost issues mentioned above, an improved syngas cooler is highly desirable. It is the intention of the present invention to provide for such an industrial need.
BRIEF SUMMARY OF THE INVENTION
Briefly described, in a preferred form, the present invention comprises a CFB syngas cooler. Circulating heat transfer media extracts heat from the syngas and subsequently transfers it to a heat removal mechanism (heat transfer surfaces), resulting in cooler syngas. In preferred embodiments, the heat transfer media comprises circulating solids, although other/additional phases of media can be used.
The cooling sequence includes contacting the circulating solids with the hot syngas and, after the syngas and circulating solids disengage, then the hot circulating solids transfer heat to the heat removal mechanism as the circulating solids move around the circulating loop. The heat removal mechanism can comprise heat transfer tubes or coils having heat transfer surfaces, where steam can be generated or saturated steam can be superheated while the circulating solids in contact with the heat transfer surfaces are being cooled via heat transfer.
In another aspect of the present invention, the CFB syngas cooler includes multiple stages of syngas cooling to raise steam at different conditions. Syngas is fed to the bottom of a riser of the present CFB syngas cooler, and the heated circulating solids are withdrawn from different elevations of the riser by gravity. The heated circulating solids exiting the riser at a certain elevation flows into a solids cooler in which installed tube bundles or heat transfer coils cool the circulating solids to a desired temperature via heat transfer. Boiler feed water or saturated steam is fed to the heat transfer surfaces for steam generation or to generate superheated steam.
In yet another aspect of the invention, the present CFB syngas cooler includes a downward flow stage to cool the hot syngas to a desired temperature and agglomerate fine molten ash droplets and other fouling substances in the gas phase. The hot syngas exchanges heat with circulating cooler solids as both syngas and circulating cooler solids flow concurrently in the downward flow stage of the cooler. The syngas reaching the fluidized bed cooler has minimal, if any, fouling materials, and thus eliminates deposition problems.
In still another aspect of the present invention, organic compounds that can be condensed such as tar and other light components are destructed in a high temperature region at the inlet of the cooler. The temperatures at the inlet of the cooler are much higher than auto ignition temperatures of syngas components, alleviating a major explosion safety concern. Also, such high temperature partial oxidation beneficially increases the CO fraction in the syngas.
In still another aspect of the present invention, the CFB syngas cooler can have multiple stages. For example, one stage of the cooler can be dedicated as steam generator, another stage as a steam superheater and reheater, and yet another stage as an economizer. The syngas is thus successively cooled to progressively lower temperatures by transferring heat to the circulating bed of solids in each stage.
In another aspect of the present CFB syngas cooler, warm syngas clean-up can be accomplished by incorporating regenerable sorbents in one or more appropriate stages of the cooler depending upon operating temperature ranges of the selected sorbents. Warm syngas clean-up sorbents are being developed for desulfurization and to capture trace components such as mercury, arsenic, cadmium and lead. Either the sorbents by themselves, or a mixture of sorbents and inert circulating solids, can be used as circulating heat transfer media to accomplish both syngas cooling and clean-up.
The syngas from a fluidized bed gasifier can contain substantial char particles. As the char particles are porous and much lighter in density, the present invention can further comprise a syngas cooler gas-solid disengagement unit and the particle collection system being optimized such that minimal-to-no char particles will accumulate in the gas cooler.
In another aspect of the present invention, a dense fluidized bed with imbedded cooling coils at the inlet of the CFB syngas cooler ensures sufficiently low syngas cooler exit temperatures for necessary time periods in case operational difficulties prevent substantial solids circulation in other downstream stages of the cooler.
In exemplary embodiments, the present invention comprises a multistage circulating fluidized bed syngas cooler to cool high temperature syngas containing entrained fouling, erosive, corrosive and condensable substances. The inlet syngas temperature can be up to about 1600° C. and, after cooling in multiple stages, the exit syngas temperature can be below about 300° C.
The multistage cooling can be accomplished with the cooler operating up to about 1000 psi with a circulating bed of solids containing particles in the range of 50 to 1000 μm.
The multistage cooling can be accomplished with a single multistage cooler capable of handling syngas flow rates up to 90 actual cubic meters per second.
The multistage cooling can be accomplished with syngas superficial velocities up to 10 meter per second through the cooler.
The multistage cooling can lead to steam generation at different steam conditions including superheated steam. One or more stages can also function as an economizer.
The particles in the cooler can agglomerate and grow to relatively larger sizes with entrained fouling substances such as molten ash droplets in the inlet syngas stream and such larger agglomerated particles are periodically withdrawn from the cooler and a portion of pulverized agglomerated ash particles in 200 to 400 μm mean size range are added back to the cooler to maintain inventory.
The heat transfer surfaces can be protected from fouling, erosive and corrosive substances in the syngas as the heat energy is extracted and transferred indirectly from the hot syngas to cooling surfaces with the circulating bed of solid particles in the cooler.
A 50 volume percent stream of oxygen along with steam and carbon dioxide can be injected into the fluid bed of solids at the inlet of the cooler to preferentially and partially oxidize the tar component in the syngas.
In another exemplary embodiment, the multistage syngas cooler is an externally circulating fluidized bed multistage cooler for cooling the high temperature syngas from a coal gasifier comprising a dense fluid bed with imbedded cooling coils in fluid contact with an inlet hot syngas stream, a riser from which a portion of circulating bed of solids enter fluidized bed coolers at different elevations and the cooled solids flow back under gravity to the riser at a lower elevation and the vent gas from the cooler flows to the riser at a higher elevation, a cyclone to disengage syngas and solids with the cooler syngas exiting the syngas cooler, a downcomer to return the cooler solids from the cyclone back to the riser, and fluidizing gas to lower portion of downcomer and dense fluid bed to segregate solids and facilitate removal of agglomerated ash.
The hot syngas entering the cooler can be cooled in successive steps as it flows through the riser portion of the cooler; first, by contacting the solids in dense fluid bed, then by contacting circulating bed of solids at the bottom of the riser and, finally, by contacting cooler solids in riser that return from fluid bed coolers in successive stages.
In another exemplary embodiment, the multistage syngas cooler is an internally circulating fluidized bed (ICFB) multistage cooler for cooling the high temperature syngas from a coal gasifier comprising a dense fluid bed with imbedded cooling coils in fluid contact with an inlet hot syngas stream and multiple stages of internally circulating fluidized bed coolers in series.
The syngas can be successively cooled in different stages to temperatures appropriate for generating desired steam and hot boiler feedwater conditions with heat transfer surfaces imbedded in fluidized and internally circulating beds.
The ICFB cooler can comprise a riser where the syngas mixes and transfer heat energy to circulating bed of solids, a disengagement section to disengage the syngas from circulating bed of solids, an annular space for circulating solids to flow down and transfer heat to imbedded heat transfer surfaces, an aeration and seal mechanism to control flow of circulating solids into riser section, and a cone section that facilitates internal solids circulation and serves as a partition between cooler stages. The cone section can further comprise steam cooled coils with small openings for a small portion of syngas to pass through and provide aeration for solids in annular space.
The syngas entering the cooler can be precooled and treated for fouling agents in an upstream stage and forming a hybrid cooler system with both external and internal circulation of solid particles.
The upstream stage can comprise an eductor to inject relatively cooler solids from last stage of multistage ICFB syngas cooler into a downflow cooler where the hot syngas inlet stream initially mixes with the injected relatively cooler solids, a high pressure recycle syngas stream as the eductor motive fluid, and a relatively cooler syngas exit stream from the downflow cooler that enters the multistage ICFB syngas cooler for further cooling.
The upstream stage can be a downflow cooler system that comprises a downflow conduit wherein the hot inlet syngas as it flows down mixes with relatively cooler solids injected at different elevations, a Presalter cyclone to disengage the syngas from agglomerated solids, a cooler with imbedded heat transfer surfaces to cool the disengaged solids from cyclone with provision for withdrawal of agglomerated solids exceeding 1000 μm in size and addition of make-up solids, a lift conduit to lift the cooled solids from the cooler with high pressure recycle syngas and inject into the downflow conduit at different elevations, and a relatively cooler syngas exit stream from the cyclone that enters the multistage ICFB syngas cooler for further cooling.
In another exemplary embodiment, the present invention is a circulating fluidized bed syngas cooler system comprising a syngas inlet stream, circulating heat transfer media, a heat removal mechanism, and a syngas outlet stream, wherein at least a portion of the circulating heat transfer media transfers at least a portion of the heat from the syngas inlet stream to the heat removal mechanism such that the temperature of syngas outlet stream is at least 500° C. cooler than the temperature of syngas inlet stream when operating at a syngas flow rate of approximately 90 m 3 /s.
On the upper end of cooling capacity when operating at high syngas inlet temperatures, the temperature difference between the syngas inlet stream and the syngas outlet stream can be up to 1300° C. at a syngas flow rate of approximately 90 m 3 /s. The system can operate up to approximately 1000 psi. The circulating heat transfer media can comprise solids having a mean particle size of between approximately 50 to 1000 μm. The syngas superficial velocity can be approximately 10 m/s.
The heat removal mechanism can comprise heat transfer tubes or coils. The heat removal mechanism can generates steam and/or superheated steam.
Circulating heat transfer media comprising an exiting mean particle size or greater can be removed from the system. The exiting particles comprise at least 1000 μm in size. At least a portion of the transfer media comprising the exiting mean particle size or greater can be removed from the system is reduced in size, and at least a portion of the reduced sized transfer media returned to the system.
The present invention can comprise a circulating fluidized bed syngas cooler system comprising a syngas inlet stream, circulating heat transfer media, at least two fluidized bed coolers, a heat removal mechanism, and a syngas outlet stream, wherein at least a portion of the circulating heat transfer media transfers at least a portion of the heat from the syngas inlet stream to the heat removal mechanism such that the temperature of syngas outlet stream is at least 500° C. and up to 1300° C. cooler than the temperature of syngas inlet stream, wherein the circulating heat transfer media comprises solids having a mean particle size of between approximately 50 to 1000 μm, wherein at least a portion of the transfer media comprising a mean particle size of 1000 μm or greater is removed from the system, and wherein a stream comprising oxygen, carbon dioxide and steam is injected into the syngas inlet stream to preferentially and partially oxidize tar components in the syngas.
The present invention can comprise a multi-stage syngas cooler for cooling high temperature syngas from a coal gasifier, the cooler comprising a dense fluid bed with imbedded cooling coils in communication with a hot syngas inlet stream, a riser from which a portion of a circulating bed of solids enter fluidized bed coolers at different elevations and cooled solids flow back under gravity to the riser at a lower elevation and vent gas from the cooler flows to the riser at a higher elevation, a cyclone to disengage syngas and solids with cooler syngas exiting the syngas cooler, a downcomer to return cooler solids from the cyclone back to the riser, and fluidizing gas to a lower portion of the downcomer and the dense fluid bed to segregate solids and facilitate removal of agglomerated ash.
These and other objects, features and advantages of the present invention will become more apparent upon reading the following specification in conjunction with the accompanying drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a preferred embodiment of an externally circulating multi-stage syngas cooler with a dense bed cooler at the bottom of the riser according to the present invention.
FIG. 2 illustrates a multi-stage internally circulating fluid bed syngas cooler with a dense bed cooler at the inlet section according to a preferred embodiment of the present invention.
FIG. 3 illustrates a hybrid cooler with a downflow cooler and a multi-stage internally circulating fluid bed syngas cooler according to a preferred embodiment of the present invention. In this cooler embodiment, the downflow cooler stage withdraws cooled solids from the last stage of the cooler through an eductor and injects the cooler solids into the downflow cooler.
FIG. 4 illustrates another embodiment of a hybrid cooler comprising an independent external solids circulating loop as a downflow cooler and a multi-stage internally circulating fluid bed cooler according to a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
To facilitate an understanding of the principles and features of the various embodiments of the invention, various illustrative embodiments are explained below. Although exemplary embodiments of the invention are explained in detail, it is to be understood that other embodiments are contemplated. Accordingly, it is not intended that the invention is limited in its scope to the details of construction and 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 carried out in various ways. Also, in describing the exemplary embodiments, specific terminology will be resorted to for the sake of clarity.
It must also be noted that, as used in the specification and the appended claims, the singular forms “a,” “an” and “the” include plural references unless the context clearly dictates otherwise. For example, reference to a component is intended also to include composition of a plurality of components. References to a composition containing “a” constituent is intended to include other constituents in addition to the one named.
Also, in describing the exemplary embodiments, terminology will be resorted to for the sake of clarity. It is intended that each term contemplates its broadest meaning as understood by those skilled in the art and includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.
Ranges may be expressed herein as from “about” or “approximately” or “substantially” one particular value and/or to “about” or “approximately” or “substantially” another particular value. When such a range is expressed, other exemplary embodiments include from the one particular value and/or to the other particular value.
Similarly, as used herein, “substantially free” of something, or “substantially pure”, and like characterizations, can include both being “at least substantially free” of something, or “at least substantially pure”, and being “completely free” of something, or “completely pure”.
By “comprising” or “containing” or “including” is meant that at least the named compound, element, particle, or method step is present in the composition or article or method, but does not exclude the presence of other compounds, materials, particles, method steps, even if the other such compounds, material, particles, method steps have the same function as what is named.
It is also to be understood that the mention of one or more method steps does not preclude the presence of additional method steps or intervening method steps between those steps expressly identified. Similarly, it is also to be understood that the mention of one or more components in a composition does not preclude the presence of additional components than those expressly identified.
The materials described as making up the various elements of the invention are intended to be illustrative and not restrictive. Many suitable materials that would perform the same or a similar function as the materials described herein are intended to be embraced within the scope of the invention. Such other materials not described herein can include, but are not limited to, for example, materials that are developed after the time of the development of the invention.
Depending upon the type of gasifier and fuel characteristics, syngas generated from gasifiers generally has a wide temperature range from approximately 800° C. to 1600° C. To maintain high process efficiencies, it is necessary to recover heat energy from the syngas while simultaneously cooling the syngas for further treatment. In addition to the wide exit temperature range, the gasifier types comprise upflow and downflow gasifiers with syngas exiting from the top or bottom of the gasifier. Both the gasifier and syngas cooler are generally tall vessels with the syngas cooler closely integrated with the gasifier. Depending on the type of gasifier and location and temperature of syngas exiting the gasifier, the components of a multi-stage syngas cooler are arranged in appropriate embodiments to limit structure height, reduce stress load and facilitate better integration.
Various embodiments of the multi-stage syngas cooler system are illustrated in FIGS. 1-4 . The present syngas coolers preferably can handle syngas containing one or more fouling, erosive and corrosive substances up to approximately 1000 psi. The preferred syngas coolers can provide approximately at least 500° C. and up to 1300° C. in cooling, and more preferably handle syngas inlet temperatures up to approximately 1600° C. and are capable of cooling the syngas to below approximately 300° C.
The configuration of the multi-stage syngas cooler 100 of FIG. 1 is mainly applied to syngas generated from downflow entrained flow gasifiers, where a portion of the coal ash is melted into molten ash droplets. In current practice with these types of gasifiers, the entire syngas generated and the molten ash droplets typically flow co-currently downward through a radiant syngas cooler before flowing through a pool of water to solidify a large portion of the molten ash droplets as slag. In the preferred syngas cooler 100 , the syngas stream 110 exiting the gasifier with entrained molten ash droplets flows into a stage 1 dense phase fluidized bed cooler S 1 DBC, or dense bed, that operates in the range of approximately 800 to 900° C. by removing heat from the inlet stream 110 while generating steam. Due to high bed temperatures and limitations on heat transfer surfaces, steam is typically generated in stage 1 cooler.
Fluidized beds comprise heat transfer media. In preferred embodiments, the heat transfer media comprises inert solids in the form of fluidizable particles, although other/additional phases of media can be used. The dense phase fluidized bed S 1 DBC is in fluid communication with a circulating fluidized bed. Molten ash droplets in the inlet stream 110 condense and agglomerate on to the heat transfer media of the dense phase bed and circulating loop.
In an exemplary embodiment, the heat transfer media comprises particles, and the initial particle size is in the range of approximately 200 to 400 microns (μm). During operation, the bed particle size distribution can be in the range of approximately 50 μm to 1000 μm as the circulating bed will entrain a portion of the fines from the inlet gas stream 110 and reach a steady state distribution. With continued operation, a portion of the particles in the dense bed and circulating loop will grow to a substantially larger size than 1000 μm due to the coating of entrained molten ash droplets. These larger particles can be selectively removed from the dense bed and lower portion of the circulating loop through segregation through stream 124 . A portion of the particles/solids withdrawn from the cooler can be pulverized to particle sizes in the range of 200 to 400 μm and fed back into the cooler through stream 125 along with the inlet syngas stream 110 . The particles fed to the cooler via stream 125 act as an agent for further agglomeration, and maintain the heat transfer media inventory in the cooler.
The syngas and solid particles entrained from the dense phase fluidized bed S 1 DBC are in the range of approximately 800 to 900° C., and mix with relatively cooler solids flowing around the loop through downcomer 113 and a non-mechanical valve 114 and also with solids exiting a stage 2 cooler S 2 CFB through its non-mechanical valve 115 . The mixed streams flow up the riser 111 and a portion of the solids stream from the riser enters the stage 2 cooler S 2 CFB. The solids rate through the cooler and the solids level 121 are maintained by controlling aeration to the non-mechanical valve 115 that connects the lower part of the stage 2 cooler S 2 CFB to the riser 111 . The solids stream is cooled while typically generating superheated steam from the stage 2 cooler S 2 CFB. Stage 2 cooler S 2 CFB and other coolers in the loop comprise fluidized bed coolers with fluidizing gas venting back into the riser through conduit 116 .
Although the vents 116 for each stage of the cooler are shown to flow back into different elevations of the riser 111 , it is feasible to practically combine all the vents with the last stage (stage 4 cooler S 4 CFB) vent and vent to one location in the circulating loop. Further, the solids from upper stages can also be routed to a lower stage to increase the solids flow rates through the coolers so as to improve the heat transfer coefficients in all the coolers.
The syngas and solids stream as it flows up the riser 111 further mixes with the relatively cooler solids stream exiting the stage 3 cooler S 3 CFB. Again, as with the stage 2 cooler S 2 CFB, a portion of the relatively heated solids stream enters the stage 3 cooler S 3 CFB.
The riser in the circulating loop can be designed to operate at a riser velocity (in the range of 4 to 10 m/s) that induces substantial solids reflux along the riser wall that promotes the flow of hot solids into the coolers. Depending upon the gasifier capacity and process needs, the stage 3 cooler S 3 CFB can be a superheater or an economizer. The features and operation of the stage 3 cooler S 3 CFB can be similar to the stage 2 cooler S 2 CFB. The process is repeated with the stage 4 cooler S 4 CFB that is typically an economizer. Thus, the syngas is cooled progressively as it flows through the dense bed and along the riser as heat is transferred to each stage of multi-stage syngas cooler with the circulating bed of solid particles.
The cooled syngas and solids stream from the riser flows through a cross-over 112 to a cyclone 117 . The solids are separated from the syngas stream in the cyclone and flows to the downcomer 113 completing the circulating loop. The cooler syngas exits the circulating loop through stream 121 . The larger solid particles from the circulating loop can be withdrawn from the bottom of the downcomer through stream 124 by segregating the solids using fluidizing gas. The solids level 121 in the downcomer 113 is maintained with make-up solids stream 125 and solids withdrawal through stream 124 . Thus, with staging, the syngas can be effectively cooled from inlet temperatures of up to 1600° C. to below 300° C. for further treatment downstream while at the same time generating steam at different conditions in various cooler stages as well as hot boiler feed water in a last cooler stage.
The syngas cooler illustrated in FIG. 1 can also be used to cool syngas containing substantial amounts of tar. In order to avoid tar condensation onto the particle surfaces in later cooler stages and downstream equipment, a carrying gas can be injected to increase the syngas temperature. For example, an oxygen stream 119 with an oxygen concentration up to 50 volume percent can be injected into stream 125 as additional carrying gas (with CO 2 and steam being the preferred remaining 50 volume percent gas) so as to increase the syngas temperature to destruct the tar components at the inlet section of the syngas cooler. The oxygen thus injected is in proportion to achieve complete partial oxidation of tar components in the syngas.
In such a partial oxidation of organic hydrocarbons constituting tar, the necessary increase in gas temperature is dependent upon the requirements for the hydrocarbon destruction, and not upon the limitation of the ash fusion temperature.
It is believed that the maximum temperature can reach approximately 1150° C. to completely destruct most if not all of the tar in the syngas when gasifying biomass or bituminous coals in a fluidized bed gasifier. Even if it is necessary to increase the syngas temperature above the ash fusion temperature, the entrained small ash particles, if fluid, will likely coat the inert circulating solid particle surfaces in the cooler. In such an embodiment, as the oxygen stream 119 is injected with steam and CO 2 and make-up solids stream 125 , the oxygen is well dispersed along with the incoming syngas stream 110 and minimizes the potential for hot spots. As the tar and some char particles in the syngas are preferentially and partially oxidized at a relatively high temperature, the main partial oxidation product is CO instead of CO 2 . The hot syngas can be immediately quenched in the first-stage cooler to a temperature in the range of approximately 800° C. to 900° C.
The syngas cooler 200 of FIG. 2 comprises a dense bed cooler and a series of ICFB coolers to generate steam at different conditions and heat the boiler feed water while cooling the syngas from up to approximately 1600° C. to below approximately 300° C. The syngas stream 210 exiting the gasifier flows through conduit 220 into a dense phase fluidized bed cooler S 1 DBC that operate in the range of approximately 800 to 900° C. The stage 1 dense bed cooler S 1 DBC with imbedded cooling coils 222 typically generates steam due to high bed temperatures and temperature limitations of heat transfer surface materials. If syngas contains a tar component, an oxygen stream 219 containing up to 50 volume percent oxygen mixed with steam and CO 2 can be injected at the inlet of the stage 1 dense bed cooler S 1 DBC to preferentially and partially oxidize tar and some char particles in the syngas.
The initial size of particles in all stages of the syngas cooler 200 is preferably in the range of 200 to 400 μm. With continued operation, a portion of particles in the dense bed grow to larger sizes due to agglomeration with fouling material in the syngas. Particles larger than approximately 1000 μm can be withdrawn through stream 224 and make-up solids added back to the cooler through stream 225 . Make-up inert solid particles in the size range 200 to 400 μm are preferably derived from pulverizing a portion of the larger size agglomerated particles withdrawn from the cooler through stream 224 . With these large size make-up inert solid particles, the disengagement section 238 in stage 2 ICFB cooler S 2 ICFB is highly efficient and virtually captures all the particles from the riser 236 and returns the particles to the cooling section 234 .
The syngas at 800 to 900° C. exits stage 1 dense bed cooler S 1 DBC and flows to the stage 2 ICFB cooler S 2 ICFB that is an internally circulating fluidized bed cooler. The syngas exiting the stage 1 dense bed cooler S 1 DBC mixes with stage 2 cooler S 2 ICFB circulating solids stream 227 . The syngas is cooled to approximately 650° C. to 700° C. by transferring heat to the solids stream as the mixture flows up the riser 236 . The gas and solids are disengaged with the aid of an inertial disengager 238 . Heated solids flowing down the annular space between the riser and shell of the vessel transfers heat to heat transfer surfaces 234 imbedded in the annular space of stage 2 cooler S 2 ICFB. Stage 2 cooler S 2 ICFB is typically a superheater in an IGCC process. The solids circulation stream 227 rate is controlled by aeration gas 226 and a non-mechanical seal mechanism 230 . The syngas transfers heat as it mixes with relatively cooler solids in lower part of the riser region 232 very quickly. As a result, the stage 2 cooler S 2 ICFB height is dependent upon the heat transfer surface area necessary to raise superheated steam at desired conditions.
It is believed that the inertial disengager 238 can have different designs to affect the separation efficiency. One of the designs is a simple Chinese hat, which completely relies on the inertia of the solids after changing direction of flow upon impinging for gas-solids separation.
Those skilled in the art can appreciate other designs for effective gas-solids separation such as having a sealed-top riser with the gas and solids stream flowing tangentially around the cylindrical shape of the separator. The separator will essentially be in the form of a cyclone and the gas-solids separation is effected by centrifugal forces.
The stage 2 cooler S 2 ICFB and its operations are separated internally from dense bed stage 1 cooler S 1 DBC through a cone shaped divider 228 that also facilitates the internal circulation of solids in stage 2 cooler S 2 ICFB. The divider 228 is further made up with steam coils with small openings or crevices for a small portion of the syngas from stage below to flow through (stream 226 ) and serve as aeration for the solids in the annular space. As the stage 1 cooler S 1 DBC does not contain a disengagement section, the solids inventory is maintained by transferring stage 2 cooler S 2 ICFB solids through conduit 229 . Overall solids inventory in cooler stages 1 and 2 as well as in cooler stages 3 S 3 ICFB and 4 S 4 ICFB and the solids level 221 in each stage are maintained by adding make-up solids through stream 225 to each stage as necessary.
The disengaged syngas from the stage 2 cooler S 2 ICFB flows to stage 3 cooler S 3 ICFB and stage 4 cooler S 4 ICFB where the syngas is further cooled to desired temperatures before exiting the syngas cooler through exit stream 250 . Depending upon the capacity of the IGCC process, the stage 3 cooler S 3 ICFB can either be a superheater or an economizer and stage 4 cooler S 4 ICFB can be an economizer. Both S 3 ICFB and S 4 ICFB are ICFB coolers and their features and functional and operational characteristics are similar to the stage 2 cooler S 2 ICFB.
In the ICFB coolers, the syngas does not come in direct contact with the heat transfer surfaces imbedded in the annular space between the riser and vessel shell. This alleviates erosion, corrosion and fouling of heat transfer surfaces due to substances that may be present in the syngas. The circulating solids stream flows down the annular space at approximately 1 to 1.5 m/s, and at such low velocities does not cause erosion of heat transfer surfaces.
Other embodiments of multi-stage syngas cooler are disclosed in FIGS. 3 and 4 that are hybrids of embodiments of those systems of FIGS. 1 and 2 and serve specific process for better integration with gasifier, general arrangement and layout needs of a gasification process. These hybrid multi-stage coolers can be used with gasifiers that have syngas exit located near the top of the gasifier and with syngas having high concentration of fouling substances and high temperatures approaching 1600° C.
The last two digits of various reference numbers designated in FIGS. 3 and 4 have either similar identifying components, streams or functionality as in FIGS. 1 and 2 . The factors differentiating the embodiments in FIGS. 3 and 4 from FIGS. 1 and 2 are described below.
The embodiment 300 disclosed in FIG. 3 uses cooler solids from stage 4 ICFB cooler S 4 ICFB through conduit 312 to initially contact the hot syngas stream 310 . As solids from stage 4 ICFB cooler S 4 ICFB are relatively at a lower pressure compared to inlet syngas stream, an eductor 340 with high pressure recycle syngas 330 boosts the pressure and facilitates solids injection. If the syngas contains tar from a fluidized bed for example, the hot syngas and the solids stream is initially contacted with a dilute oxygen stream 319 to preferentially and partially oxidize the tar components in the syngas. The relatively cooler educted solids mixes with hot syngas as both streams flow down the stage 1 downflow cooler 313 before entering the stage 2 dense bed cooler S 1 DBC through conduit 320 where the solids exchange heat with imbedded heat transfer surfaces to generate steam. The arrangement, function and operation of stage 2 dense bed cooler S 1 DBC and stages 3 and 4 ICFB coolers are similar to the description of corresponding coolers of embodiment 200 disclosed in FIG. 2 . The syngas is successively cooled in each stage before exiting through stream 350 . The solids level 321 in each of the last three stages of embodiment 300 is maintained by withdrawal of oversized agglomerated solids stream 324 from the stage 2 dense bed cooler and the addition of make-up solids through stream 325 . The make-up solids in the size range approximately 200 to 400 μm are derived from pulverizing agglomerated solids.
The embodiment 400 shown in FIG. 4 provides more flexibility in cooling the syngas as it comprises an independent stage 1 circulating downflow cooler. The hot syngas inlet stream 410 with fouling substances mix with cooler solids stream 415 injected at various elevations and both streams flow down and through an inclined conduit 414 enter a Presalter cyclone 417 as disclosed in U.S. Pat. No. 7,771,585, incorporated herein in full by reference. A dilute oxygen stream 419 as in embodiments in FIGS. 1 to 3 is injected along with stream 415 at upper elevation of conduit 413 to preferentially and partially oxidize tar component that may be present in the syngas.
As the syngas and relatively cooler solids stream mix and flow down the conduit 413 , molten ash droplets in the syngas condense and agglomerate with the injected cooler solid particles. The solids stream from the cyclone is cooled in the stage 1 cooler by exchanging heat with heat transfer surfaces and generating steam. Recycle syngas at higher pressure injected into the cooler through stream 430 lifts the solids from the cooler through conduit 411 for reinjection.
Oversize agglomerated solids are withdrawn from the stage 1 cooler through stream 424 and make-up solids in the particle size range of approximately 200 to 400 μm, derived from pulverizing agglomerated solids, are added back to the cooler through stream 425 .
The syngas stream 420 exiting the cyclone enters the stage 2 dense bed cooler and stages 3 and 4 ICFB coolers for further cooling before exiting the multi-stage fluid bed cooler embodiment 400 through stream 450 . The arrangement, function and operation of stage 2 dense bed cooler and stages 3 and 4 ICFB coolers are similar to the corresponding coolers described of embodiment 200 disclosed in FIG. 2 . Solids level 421 in the stage 1 downflow cooler and other stages of the embodiment 400 are maintained as necessary through solids addition to each stage with stream 425 and oversize solids withdrawal through stream 424 . As the stage 1 downflow cooler operation is independent of other stages, the embodiment of FIG. 4 provides more flexibility in operation and cooling capacity and can handle syngas with high inlet temperatures up to approximately 1600° C.
As with other embodiments, the syngas as it flows through embodiments 300 and 400 disclosed in FIGS. 3 and 4 does not directly contact the heat transfer surfaces, and thus avoids difficulties associated with corrosion, erosion and fouling. Further, the multiple cooling stages with circulating bed of solids in these embodiments facilitate generation of hot boiler feed water and steam at different conditions including superheated steam necessary for an IGCC process to generate power.
As heat transfer surfaces are protected from high inlet temperatures as well as corrosive, erosive and fouling characteristics of syngas, various embodiments of the multi-stage syngas cooler disclosed herein can be operated at high superficial gas velocities in the range of approximately 4 to 10 m/s that facilitates a single multi-stage syngas cooler to handle syngas flow rates up to 90 m 3 /s which is larger than any single gasifier can deliver.
Numerous characteristics and advantages have been set forth in the foregoing description, together with details of structure and function. While the invention has been disclosed in several forms, it will be apparent to those skilled in the art that many modifications, additions, and deletions, especially in matters of shape, size, and arrangement of parts, can be made therein without departing from the spirit and scope of the invention and its equivalents as set forth in the following claims. Therefore, other modifications or embodiments as may be suggested by the teachings herein are particularly reserved as they fall within the breadth and scope of the claims here appended.
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A method and apparatus for cooling hot gas streams in the temperature range 800° C. to 1600° C. using multi-stage circulating fluid bed (CFB) coolers is disclosed. The invention relates to cooling the hot syngas from coal gasifiers in which the hot syngas entrains substances that foul, erode and corrode heat transfer surfaces upon contact in conventional coolers. The hot syngas is cooled by extracting and indirectly transferring heat to heat transfer surfaces with circulating inert solid particles in CFB syngas coolers. The CFB syngas coolers are staged to facilitate generation of steam at multiple conditions and hot boiler feed water that are necessary for power generation in an IGCC process. The multi-stage syngas cooler can include internally circulating fluid bed coolers, externally circulating fluid bed coolers and hybrid coolers that incorporate features of both internally and externally circulating fluid bed coolers. Higher process efficiencies can be realized as the invention can handle hot syngas from various types of gasifiers without the need for a less efficient precooling step.
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FIELD OF THE INVENTION
The present invention relates to a vehicular suspension interlock system to restrain suspension travel during a rear impact event.
BACKGROUND OF THE INVENTION
Modern automotive vehicles typically have impact absorbing devices located in their rear areas to absorb impact forces and also channel impact forces into the vehicle frame during a vehicular rear impact event. In addition to the impact absorbing devices, vehicles may be equipped with rear suspension devices that usually do not function in conjunction with the rear impact absorbing devices during a rear impact event. While current impact absorbing devices have proven satisfactory for their applications, each is associated with its share of limitations. One limitation with rear impact absorbing devices is that they are designed to absorb all or most of the impact forces experienced by the rear of the vehicle during a rear impact. Another limitation is that current rear impact absorbing devices do not channel impact forces to other rear areas of the vehicle structures to utilize the impact absorbing capabilities of other rear area structures during a vehicular rear impact.
What is needed then is a device that does not suffer from the above limitations. This, in turn, will provide a vehicular device that, during a rear impact event, works in conjunction with the rear impact absorbing devices and channels the force of impact through additional areas of the vehicular frame.
SUMMARY OF THE INVENTION
A suspension interlock system for a vehicle having a rear suspension system that supports a vehicle frame further secures the rear suspension system to the vehicle frame. To secure the rear suspension system to the vehicle frame, the suspension interlock system may be a flexible member attached to the vehicle frame and the rear suspension system or a u-shaped bar attached to the vehicular frame that surrounds a pin attached to the rear suspension system.
Further areas of applicability of the present invention will, become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIG. 1 is a side view of a rear suspension depicting the placement of a suspension interlock device of a first embodiment of the present invention;
FIG. 2 is a side view of a rear suspension depicting the placement of a suspension interlock device of a second embodiment of the present invention;
FIG. 3 is a perspective view of a rear suspension depicting the location of a suspension interlock system in front of the rear axle according to a third embodiment of the present invention;
FIG. 4 is a side view of the rear suspension interlock system of FIG. 3 ;
FIG. 5 is a perspective view of a hook and loop arrangement of a suspension interlock system according to a fourth embodiment of the present invention;
FIG. 6 is a side view of the hook and loop arrangement according to the fourth embodiment of the present invention;
FIG. 7 is a side view of the suspension interlock system prior to a vehicular rear impact; and
FIG. 8 is a side view of the suspension interlock system during a rear impact event.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. Turning first to FIG. 1 , the components of a first embodiment of the suspension interlock system will be explained. The suspension interlock system 10 of a first embodiment is primarily composed of an interlock cable 12 , a vehicular frame rail 14 and a trailing link bracket 16 . The interlock cable 12 may be a cable with a circular cross-section sufficient in strength to achieve its purpose, which will be described later. The interlock cable 12 may be made from any one of a variety of materials, such as steel, titanium, etc. that are capable of providing sufficient strength. The cable 12 could also be a blend of metals or a non-metal material such as Kevlar.
A first end of the cable 12 is connected to the frame rail 14 by a fastener, such as a bolt 18 ; however, any acceptable fastening means may be used, including but not limited to, a rivet, a screw, or welding the cable 12 to the frame rail 14 . The trailing link bracket 16 secures an end of the upper trailing link 20 and an end of the lower trailing link 22 of the suspension system 24 . The opposite ends ( FIGS. 7 and 8 ) of the links 20 , 22 may be fixed to the frame rail 14 with brackets. Similarly to the first end of the cable 12 , the second end of the cable 12 is attached to the trailing link bracket 16 by a bolt 30 ; however, any acceptable fastening means can be used, such as rivets, screws, welding, etc.
The suspension system 24 also entails a coil spring 26 that abuts against and attaches to the frame rail 14 . The coil spring 26 works in conjunction with a shock absorber 28 to provide the proper support to the frame 14 , and thus, the vehicle in which the suspension system 24 is installed. One end of the shock absorber 28 may be attached to a shock bracket 29 , while the other end of the shock absorber 28 may be attached to the frame 14 . The shock bracket 29 may also be attached to, or integrally a part of, the trailing link bracket 16 .
In a second embodiment of the present invention, depicted in FIG. 2 , a flat strap 32 is employed instead of the round cable 12 of the first embodiment. Because the flat strap 32 has an elongated oval or square cross-section, an advantage of the flat strap 32 over the round cable 12 is its potential to be folded into a more compact package, and its potential to flex in predictable directions, such as along the longer of its flat edges, when viewed in cross-section. Since the flat strap 32 may be predicted to fold and flex in certain directions, it may be packaged within a suspension system more advantageously. That is, because certain vehicles may have limited space within which to place such a suspension restraint, the flat strap 32 may be more advantageous than other cables or other restraint options. Additionally, the flat strap 32 may provide more advantageous mounting against the flat frame rail 14 because the flat strap 32 also has a wider, flat surface to provide a slimmer, lower-profile mount with comparatively more surface area than a circular cable. However, it is conceivable that either the circular cable 12 or the flat strap 32 may be secured into a mounting tab 33 before the mounting tab 33 is secured to the frame rail 14 . By using a mounting tab 33 , securing either the circular cable 12 or the flat strap 32 to the frame rail 14 may be performed in a more consistent fashion.
Turning to FIG. 3 , the present invention according to a third embodiment is depicted. FIG. 3 only depicts pertinent portions of the third embodiment of the suspension interlock system and omits other, unnecessary portions of the vehicle in exhibiting the operative workings of the third embodiment. FIG. 3 depicts the trailing link bracket 16 mounted to the vehicle axle 48 and shows the upward direction 50 and downward direction 52 that the axle 48 may move when a vehicle is in use or undergoes a rear impact event. Also depicted is a loop 42 and pin 46 arrangement. The loop 42 is attached to the frame rail 14 by an acceptable means such as by using a bolted bracket (not shown) to secure the loop 42 to the frame rail 14 , by welding, etc. When the vehicle is in use, the vehicle axle 48 moves upward and downward such that the securing pin 46 moves within the confines of the loop 42 and frame rail 14 . The significance of the pin 46 remaining within the confines of the loop 42 and the frame rail 14 will be discussed later. Additionally, the pin plate 44 , to which the pin 46 is attached to, may be secured to the axle 48 .
FIG. 4 is a side view of the third embodiment of the suspension interlock system 40 . In the side view of FIG. 4 , the rear wheel (not shown) is removed to permit viewing of components of the suspension interlock system 40 . The loop 42 is shown to possess a front bar 41 and a rear bar 43 . Additionally, the loop 42 and pin 46 are located in front of the axle; however, the loop 42 and pin 46 could be located behind the axle 48 or even over the axle 48 depending upon the packaging requirements of the vehicle in which the suspension interlock system 40 is installed.
FIG. 5 is a perspective view of a fourth embodiment of a suspension interlock system 60 of the present invention. The suspension interlock system 60 of the fourth embodiment includes a loop 66 that may be a steel bar loop that is generally formed of an outside bar 70 and an inside bar 68 . The outside bar 70 has a hook 72 that may be used for mounting purposes. Generally, the loop 66 mounts between the frame rail 14 and the bracket 74 , which holds the loop 66 in place during its use as a suspension interlock device. The plate 62 has a hook 64 that is located between the inside bar 68 and outside bar 70 . The hook 64 is permitted to travel within the confines of the loop 66 with the loop acting as a restraining device to prevent the hook 64 portion of the plate 62 from moving beyond the confines of the loop 66 . Because the plate 62 is attached to components of the vehicle suspension system, the hook 64 , plate 62 and loop 66 prevent the suspension system from separating from adjacent the vehicle frame 14 . The plate 62 may be mounted to the trailing link bracket 16 , axle 48 , or other suitable component.
FIG. 6 is a side view of the suspension interlock system 60 of the fourth embodiment of the present invention. FIG. 6 depicts the positional relationship of the inside bar 68 , outside bar 70 , the plate 62 , and plate hook 64 . As shown, the plate hook 64 protrudes from the plate 62 such that the plate hook 64 passes through the loop 66 . The bracket 74 secures the inside bar 68 and outside bar 70 from moving away from the frame rail 14 . Although shown secured with a bracket 74 , the inside bar 68 and outside bar 70 may be secured by welding the bars 68 , 70 to the frame rail 14 .
The operative workings of the various embodiments of the present invention will now be presented. FIGS. 7 and 8 depict the rear of a vehicle 93 in which the suspension interlock system 60 depicted in FIGS. 5 and 6 is invoked; however, the operative workings of the various embodiments are similar and the effects of the various embodiments are designed to be equal. In explaining the operative workings as they relate to FIGS. 5 and 6 , the operative workings of the other embodiments may be presented. FIGS. 7 and 8 depict a load 90 that possess a force represented by force arrow 92 . The load 90 and force are directed toward the rear of the vehicle 93 . The load 90 is representative of an impacting vehicle that may strike the rear end of the vehicle 93 in a rear impact event of the vehicle 93 . FIG. 7 depicts the upper trailing link 20 and lower trailing link 22 in their pre-impact, horizontal positions. The axle 48 is positioned between the upper trailing link 20 and lower trailing link 22 . At each end of the axle 48 a wheel 97 is attached. The differential 94 is shown protruding rearward of the axle 48 , both of which are positioned adjacent the spare wheel 96 . Although a spare wheel 96 is described, the spare wheel 96 location could also be occupied by a spare wheel container, a storage recession in the rear floor of the vehicle 93 , or other object that might occupy the space depicted as a spare wheel 96 .
As depicted in FIG. 8 , when the load 90 strikes the vehicle 93 at impact location 98 during a rear impact event as an example, the frame rail 14 is affected by a force, as depicted with force arrow 100 , while the spare wheel 96 is affected by a force, as depicted with force arrow 102 . The force arrows 100 , 102 are the transfer and absorption of the load force of load 90 . The force of impact 92 causes the spare wheel 96 to be directed into the rear axle assembly 104 , namely the differential 94 , the rear axle 48 , and rear suspension links 20 , 22 . When the spare wheel 96 meets the rear axle assembly 104 , the impact force of such meeting causes the rear axle assembly 104 to begin pivoting about pivot point 106 of the upper trailing link 20 , and pivot point 108 of the lower trailing link 22 . The pivoting about pivot points 106 , 108 is due to a downward force acting on the upper trailing link 20 and lower trailing link 22 from the force 102 acting on the differential cover 94 , rear axle 48 , and other rear suspension components.
As the spare wheel 96 force 102 acts on the rear axle assembly 104 , forces act concurrently through the upper trailing link 20 as shown by force 110 and lower trailing link 22 as force 112 . The forces in the trailing links 20 , 22 are immediately transferred into the frame rail 14 , the process of which will now be explained.
The forces resulting from the load 90 impact are initially divided between the frame rail 14 and the spare wheel 96 . An advantage of the present invention is that the force that impacts the spare wheel 96 is then transferred into the frame rail 15 in a more forward position in front of the rear axle assembly 104 through the rear suspension components such as the upper trailing link 20 and lower trailing link 22 . By dividing and transferring the impact force from force arrow 92 to both force arrow 100 and force arrow 102 , the force of impact is more evenly distributed than if the frame rail 14 completely absorbs all of the impact. By dividing the force, the impact load subjected to the frame rail 14 aft of the rear axle assembly 104 is lessened. This permits more of the load 90 to be absorbed by more of the vehicle structure, more specifically, the frame rail 15 in front of the rear suspension instead of that part of the frame rail above the spare wheel 96 . Without the suspension interlock system of the present invention, the frame rail 14 above the spare tire 96 absorbs all of the impact forces from the rear impact. This may cause the frame rail 14 to buckle as the rear suspension components move away from the frame rail 14 due to the impacting forces. Generally, the rear suspension components and rear axle assembly 104 are not able to absorb the rear impact forces when they separate from the frame rail 14 during a rear impact.
To accomplish this force distribution, the suspension interlock system depicted in FIGS. 7 and 8 will be explained. When the load 90 strikes the rear end of vehicle 93 , the frame rail 14 may begin to buckle upwards in accordance with direction arrow 99 . As the load 90 continues moving into the rear of the vehicle 93 , the load strikes the spare wheel 96 , which may be forced into the rear axle assembly 104 . When the rear axle assembly 104 makes contact with the load 90 , the rear axle assembly 104 begins moving downward according to arrow 101 , which invokes the suspension interlock system 60 . FIGS. 7 and 8 do not show the relative repositioning of the frame 14 and rear wheel 96 . Instead, the result of such repositioning is reflected in the rear axle assembly 104 .
With reference to FIGS. 5-8 , the inside bar 68 and outside bar 70 , together with the frame rail 14 , contain the hook 64 of plate 62 . Upon the impact of load 90 , the inside bar 68 and outside bar 70 remain attached to, and move in conjunction with, the frame rail 14 . The hook 64 , which protrudes from the plate 62 , begins moving downward in accordance with arrow 101 as the rear axle assembly 104 begins pivoting downward, which is also clockwise in FIG. 8 , about pivot points 106 , 108 . As the rear axle assembly 104 continues pivoting about pivot points 106 , 108 , the hook 64 , moving downward, eventually reaches the confining limit 65 ( FIG. 5 ) of the confining inside bar 68 and outside bar 70 . When the hook 64 reaches the confining limit 65 , the rear axle assembly 104 stops independently pivoting about pivot points 106 , 108 .
With the hook 64 of the plate 62 at its confining limit 65 , the inside bar 68 and outside bar 70 are placed into tension. When placed under tension, two occurrences become evident. The first occurrence is that the frame rail 14 and rear axle assembly 104 begin to bear the load in concert, as opposed to the frame rail 14 alone, since the rear axle assembly 104 is restrained by the hook 64 within the inside bar 68 and outside bar 70 . The second occurrence is that the rear axle assembly 104 is held adjacent the frame rail 14 , proximate its pre-collision position. Because the rear axle assembly 104 is held adjacent the frame rail 14 , the rear axle assembly 104 is held in the line of force 92 and receives a force 102 .
With the force 102 passing into the spare wheel 96 , which contacts the differential 94 and axle 48 , the force 102 then passes into the upper trailing link 20 as evidenced by force arrow 110 and the lower trailing link 22 as evidenced by the force arrow 112 . Upon the forces 110 , 112 passing into the links 20 , 22 they then pass into the frame rail 15 . More specifically, the force passing through the upper trailing link 20 passes into the frame rail 15 as force 114 and then the combined force of force 114 and the lower trailing link force 112 combine as force 116 , which passes into the frame rail 15 in front of the rear axle assembly 104 .
While FIGS. 7 and 8 depict a plate 62 , hook 64 , and loop 66 arrangement, the arrangements of other embodiments will accomplish the same task. For example, if the circular cable 12 ( FIG. 1 ) or flat cable 32 ( FIG. 2 ) is utilized in place of the plate 62 , hook 64 , and loop 66 arrangement, when the impact of the load 90 strikes the vehicle 93 , the result is the same. For instance, since the cable 12 and flat cable 32 are attached to the frame 14 and the suspension system, such as the trailing link bracket 16 , the cable 12 , 32 will extend as far as its length will permit as the axle assembly pivots as a result of the impact, and then the cable 12 , 32 will reach its limit. When the cable 12 , 32 , reaches its limit, the rear axle assembly 104 is held adjacent the frame rail 14 , proximate its original, non-impact position to transfer forces into the frame rail 15 in front of the rear axle assembly 104 in accordance with the force transfer described above.
Like the cable 12 , 32 and the plate 62 , hook 64 , and loop 66 arrangement, the loop 42 and pin 46 arrangement of FIGS. 3 and 4 could be used to restrain the rear vehicle suspension, including the rear axle assembly 104 adjacent the rear frame rail 14 . During a rear impact event, when the rear axle assembly 104 moves downward, the pin 46 moves within the loop 42 until the pin 46 meets the limit of its travel within the loop 42 . When this occurs, the rear axle assembly 104 is held adjacent the frame rail 14 , proximate its original, non-impact position to transfer forces into the frame rail 15 in front of the rear axle assembly 104 ( FIGS. 7 and 8 ), in accordance with the force transfer described above.
An advantage of the above embodiments of the invention is that the frame rail 14 and the rear axle assembly 104 share the load 90 of a rear impact collision, and the rear axle assembly is held under the frame rail 14 , proximate its original position. Additionally, more of the force of the impact is directed into the frame rail 15 , as indicated by the force arrows 102 , 110 , 112 , 114 , and 116 .
The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.
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A vehicle having a suspension system that supports a vehicle frame has a suspension interlock for governing the distance that the suspension system may move away from the frame during a vehicular rear impact event, thereby channeling impact forces through the suspension system and into the vehicle frame. A flexible member attaches to the vehicle frame and to the suspension system and acts as a tether to maintain the position of the suspension system relative to the frame. Alternatively, the suspension interlock may be a u-shaped bar mounted to the vehicular frame that interacts with a pin that is mounted to the suspension system. The pin resides within the confines of the u-shaped bar to maintain the position of the suspension system relative to the frame. Alternatively, a hooked plate may be used instead of a pin.
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CROSS-REFERENCE TO RELATED APPLICATIONS/INCORPORATION BY REFERENCE
[0001] [Not Applicable.]
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] [Not Applicable]
[MICROFICHE/COPYRIGHT REFERENCE]
[0003] [Not Applicable]
BACKGROUND OF THE INVENTION
[0004] Network traffic for real-time media consists of one or more streams of data packets, each stream supporting one “channel”. Each packet of the stream provides a limited amount of playback time for the associated channel. In order to provide continuous playback, the data packets for each channel must arrive at regular intervals. The time that a packet takes to traverse the network varies, however, due to a number of factors. These factors include, for example, the number of nodes, the speed of the communications links, and the queuing delay that occurred at each node in the path. In addition, data packets may be lost in transit. Packet loss and variations in network delay, normally referred to as ‘network delay jitter’, occur as a part of normal packet network operation. Minimizing the effects of network delay jitter and packet loss on the playback of a real-time media stream is a challenging problem, and involves the buffering of the compressed real-time data at the point of playback for each channel. The buffers used for this purpose are referred to as “jitter buffers”.
[0005] Each packet in the data stream for a channel includes a small amount of packet header information, and a much larger amount of compressed real-time data, or “payload.” Typically, the packet header and the payload are stored together in the jitter buffer for that channel. Although the information in the packet header is used repeatedly by the jitter buffer algorithms, the payload is accessed only when decompression occurs.
[0006] The digital signal processors typically used to implement the decompression algorithms have a relatively small amount of fast, internal data memory. When a typical jitter buffer is stored within the internal data memory of the digital signal processor, it occupies a large portion of that space. Each channel that is supported also requires a certain amount of memory space during decompression for program or “instance” variables. The combined memory requirement of the jitter buffer and the instance variables limits the number of channels that may be supported by the internal memory of the typical digital signal processor. As an alternative, the jitter buffer may be stored in a larger external memory. Storing the jitter buffer in external memory, however, slows access to the packet header information needed for the jitter buffer algorithms. The slower access to packet header information reduces processor throughput, limiting the number of channels that may be supported.
[0007] Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present invention as set forth in the remainder of the present application with reference to the drawings.
BRIEF SUMMARY OF THE INVENTION
[0008] Aspects of the present invention may be seen in a decoder comprising a processor for executing at least one decompression algorithm, the processor comprising a first memory, and a second memory for storing at least one of the payload data, header data, and algorithm instance data. At least one of the header data, the payload data, and the algorithm instance data may be moved from the second memory to the first memory just prior to the execution of the at least one decompression algorithm, and at least one of the header data and the algorithm instance data may be moved from the first memory to the second memory following the execution of the at least one decompression algorithm. The payload data may comprise speech data, and the header data may comprise at least one of a time stamp, a sequence number, a jitter estimate, and a reference to a location within the second memory.
[0009] In an embodiment of the present invention, the size of the first memory may be a small fraction of the size of the second memory. In addition, the first memory may have a relatively higher speed of access and the second memory may have a relatively lower speed of access. The at least one decompression algorithm may be executed on a periodic basis.
[0010] Another aspect of the present invention may be observed in a method of operating a decoder for decoding a real-time media stream, the method comprising receiving a plurality of data packets where each of the plurality of data packets may comprise header data and payload data, and parsing each of the plurality of data packets into a header data portion and a payload data portion. The method may further comprise storing the header data portions in a first memory, thereby forming a block of header data, and storing the payload data portions in the first memory, thereby forming a block of payload data. The method may also comprise copying the block of header data to a second memory, decoding at least a portion of the block of payload data using the copy of the block of header data in the second memory, and moving at least a portion of the copy of the block of header data in the second memory back to the first memory.
[0011] In an embodiment in accordance with the present invention, the payload data may comprise compressed speech data, and the header data may comprise at least one of a time stamp, a sequence number, a jitter estimate, and a reference to a location within the first memory. In addition, the second memory and a digital signal processor may be contained within a single integrated circuit device. The size of the second memory may be a small fraction of the size of the first memory, and the copying, decoding, and moving may occur on a periodic basis.
[0012] Yet another aspect of the present invention may be observed in a machine-readable storage, having stored thereon a computer program having a plurality of code sections for implementing a decoder, the code sections executable by a machine for causing the machine to perform the foregoing.
[0013] These and other advantages, aspects, and novel features of the present invention, as well as details of illustrated embodiments, thereof, will be more fully understood from the following description and drawings.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
[0014] [0014]FIG. 1 is a functional block diagram representing a communication system that enables the transmission of real-time media data over a packet-based system.
[0015] [0015]FIG. 1A is a functional block diagram representing another communication system that enables the transmission of real-time media data over a packet-based system.
[0016] [0016]FIG. 2 is a block diagram of an exemplary embodiment illustrating the services invoked by a packet voice transceiver system, in accordance with the present invention.
[0017] [0017]FIG. 3 is a more detailed block diagram showing the network services invoked by the network VHD operating in the voice mode and the associated PXD.
[0018] [0018]FIG. 4 shows a block diagram illustrating the storage arrangement of a jitter buffer in which the header data and payload data have been stored in separate memory areas having different speed of access, in accordance with the present invention.
[0019] [0019]FIG. 5 shows a block diagram of an exemplary decoder that may correspond, for example, to the decoder of FIG. 2, in accordance with the present invention.
[0020] [0020]FIG. 6 is a flow chart illustrating a method of operating a decoder, in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0021] The invention described relates in general to the processing of a payload media stream. More specifically, the present invention pertains to the processing of multiple, compressed, real-time media streams in a system with limited high-speed memory.
[0022] In an illustrative embodiment of the present invention, a signal processing system is employed to interface voice telephony devices with packet-based networks. Voice telephony devices include, by way of example, analog and digital phones, Ethernet phones, IP phones, interactive voice response systems, private branch exchanges (PBXs) and any other conventional voice telephony devices known in the art. The described embodiment of the signal processing system can be implemented with a variety of technologies including, by way of example, embedded communications software that enables transmission of voice data over packet-based networks. The embedded communications software may be run on programmable digital signal processors (DSPs), and used in gateways, remote access servers, PBXs, and other packet-based network appliances. Although the embodiments described below are with respect to the use of the invention(s) within systems performing voice communication, the embodiments described herein are for illustrative purposes only, as the present invention is not limited in this respect and may have significant utility in systems used for the communication of other real-time media, for example, voice, music, video, etc.
[0023] Referring now to FIG. 1, there is shown a functional block diagram representing a communication system that enables the transmission of voice data over a packet-based system such as voice-over-IP (VoIP, H.323), Voice over Frame Relay (VoFR, FRF-11), Voice Telephony over ATM (VTOA), or any other proprietary network, according to an illustrative embodiment of the present invention. In one embodiment of the present invention, voice data can also be carried over traditional media such as time division multiplex (TDM) networks and voice storage and playback systems. Packet-based network 10 provides a communication medium between telephony devices. Network gateways 12 a and 12 b support the exchange of voice between packet-based network 10 and telephony devices 13 a and 13 b . Network gateways 12 a and 12 b may include a signal processing system that provides an interface between the packet-based network 10 and telephony devices 13 a and 13 b . Network gateway 12 c supports the exchange of voice between packet-based network 10 and a traditional circuit-switched network 19 , which transmits voice data between packet-based network 10 and telephony device 13 c . In the described exemplary embodiment, each network gateway 12 a , 12 b , 12 c supports a telephony device 13 a , 13 b , 13 c.
[0024] Each network gateway 12 a , 12 b , 12 c could support a variety of different telephony arrangements. By way of example, each network gateway might support any number of telephony devices, circuit-switched networks and/or packet-based networks including, among others, analog telephones, Ethernet phones, fax machines, data modems, PSTN lines (Public Switched Telephone Network), ISDN lines (Integrated Services Digital Network), T1 systems, PBXs, key systems, or any other conventional telephony device and/or circuit-switched/packet-based network. In the described exemplary embodiment, two of the network gateways 12 a , 12 b provide a direct interface between their respective telephony devices and the packet-based network 10 . The other network gateway 12 c is connected to its respective telephony device through a circuit-switched network such as a PSTN 19 . The network gateways 12 a , 12 b , 12 c permit voice, fax and modem data to be carried over packet-based networks such as PCs running through a USB (Universal Serial Bus) or an asynchronous serial interface, Local Area Networks (LAN) such as Ethernet, Wide Area Networks (WAN) such as Internet Protocol (IP), Frame Relay (FR), Asynchronous Transfer Mode (ATM), Public Digital Cellular Network such as TDMA (IS-13x), CDMA (IS-9x), or GSM for terrestrial wireless applications, or any other packet-based system.
[0025] Another exemplary topology is shown in FIG. 1A. The topology of FIG. 1A is similar to that of FIG. 1 but includes a second packet-based network 16 that is connected to packet-based network 10 and to telephony device 13 b via network gateway 12 b . The signal processing system of network gateway 12 b provides an interface between packet-based network 10 and packet-based network 16 in addition to an interface between packet-based networks 10 , 16 and telephony device 13 b . Network gateway 12 d includes a signal processing system that provides an interface between packet-based network 16 and telephony device 13 d.
[0026] Referring now to FIG. 2, there is illustrated a signal flow diagram of a packet voice transceiver system 200 , in accordance with an embodiment of the present invention. In an illustrative embodiment of the present invention, the packet voice transceiver system 200 may reside in a network gateway such as network gateways 12 a , 12 b , 12 c of FIG. 1, and 12 a , 12 b , 12 c , and 12 d of FIG. 1A. In an exemplary embodiment, packet voice transceiver system 200 provides two-way communication with a telephone or a circuit-switched network, such as a PSTN line (e.g. DSO). The packet voice transceiver 200 includes a Virtual Hausware Driver (VHD) 205 , a switchboard 210 , a physical device driver (PXD) 215 , an interpolator 220 , and a decimator 225 .
[0027] The VHD 205 is a logical interface to a telephony device such as 13 a , 13 b , and 13 c of FIG. 1, via the packet network 10 , and performs functions such as voice encoding and decoding, media queue management, dual tone multi-frequency (DTMF) detection and generation, and call discrimination (CDIS). During a communication session (e.g., voice, video, fax) each telephony device associates a VHD 205 with each of the telephony device(s) with which it is communicating. For example, during a voice-over-packet (VoIP) network call between telephony devices 13 a and 13 b , telephony device 13 a associates a VHD 205 with telephony device 13 b , and telephony device 13 b associates a VHD 205 with telephony device 13 a . Communication between telephony devices 13 a and 13 b takes place through their respective VHD 205 , and packet network 10 .
[0028] The switchboard 210 associates the VHD 205 and the PXD 215 engaged in a communication session by supporting the connection and combination of data streams from the VHD 205 and PXD 215 assigned to the telephony devices participating in the session.
[0029] The PXD 215 represents an interface for transmitting and receiving the input and output signals to and from the user, and performs various functions including, for example, echo cancellation. As shown in FIG. 2, the top of the PXD 215 interfaces with switchboard 210 , while the bottom of the PXD 215 passes data to the interpolator 220 and receives data from decimator 225 . The functions within a wideband PXD 215 may be designed to use, for example, 16 kHz sampled data, while functions in a narrowband PXD 215 may expect to process, for example, 8 kHz sampled data.
[0030] A wideband system may contain a mix of narrowband and wideband VHDs 205 and PXDs 215 . A difference between narrowband and wideband device drivers is their ingress and egress sample buffer interface. A wideband VHD 205 or PXD 215 has wideband data at its sample buffer interface and includes wideband services and functions. A narrowband VHD 205 or PXD 215 has narrowband data at its sample buffer interface and can include narrowband services and functions. The switchboard interfaces with narrowband and wideband VHDs 205 and PXDs 215 through their sample buffer interfaces. The switchboard 210 is incognizant of the wideband or narrowband nature of the device drivers, but is aware of the sampling rate of the data that it reads and writes data through the sample buffer interfaces. To accommodate differences in the sampling rates of data streams, an embodiment of the present invention may upsample data received from narrowband sources and downsample data being sent to narrowband destinations. The sample buffer interfaces may provide data at any arbitrary sampling rate. In an embodiment of the present invention, the narrowband sample buffer interface may provide data sampled at 8 kHz and the wideband sample buffer interface may provide data sampled at 16 kHz. Additionally, a VHD 205 may be dynamically changed between wideband and narrowband and vice versa.
[0031] The VHD 205 and PXD 215 driver structures may include sample rate information to identify the sampling rates of the wideband and narrowband data. The information may be part of the interface structure that the switchboard understands and may contain a buffer pointer and an enumeration constant or the number of samples to indicate the sample rate.
[0032] The packet voice transceiver system 200 is also characterized by an ingress path and an egress path, in which the ingress path transmits user packets to a packet network such as, for example, packet network 10 of FIG. 1, and the egress path receives user packets from a packet network such as, for example, packet network 10 of FIG. 1. The ingress path and the egress path can either operate in a wideband support mode or a narrowband support mode, and the ingress path and the egress path are not required to operate in the same mode. For example, the ingress path can operate in the wideband support mode, while the egress path operates in the narrowband mode.
[0033] In the exemplary embodiment shown in FIG. 2, the ingress path comprises the decimator 225 , echo canceller 235 , switchboard 210 , and services including but not limited to DTMF detector 240 and CDIS 245 , and packet voice engine (PVE) 255 comprising an encoder algorithm 260 , and packetization function 261 . In the ingress path of a wideband device, the decimator 225 receives the user inputs and provides, for example, 16 kHz sampled data for an 8 kHz band-limited signal. The 16 kHz sampled data is transmitted through echo canceller 235 and switchboard 210 to the VHD 205 associated with the destination telephony device. In some cases, the DTMF detector 240 may be designed for operation on only narrowband digitized samples, and the wideband data may be downsampled and passed to DTMF detector 240 . Similarly, where CDIS 245 is designed for operation on only narrowband digitized samples, downsampled wideband data may be provided to CDIS 245 , which distinguishes a voice call from a facsimile transmission.
[0034] The PVE 255 is responsible for issuing media queue mode change commands consistent with the active voice encoder and decoder. The media queues can comprise, for example, the media queues described in patent application Ser. No. 10/313,826, “Method and System for an Adaptive Multimode Media Queue”, filed Dec. 6, 2002, which is incorporated herein by reference in its entirety. The PVE 255 ingress thread receives raw samples from other functions within VHD 205 . Depending upon the operating mode of VHD 205 , the raw samples include either narrowband or wideband data. At PVE 255 , encoder 260 encodes and packetizes the sampled data into compressed speech frames for transmission over a packet network such as, for example, packet network 10 of FIG. 1. The encoder 260 can comprise, for example, the BroadVoice 32 Encoder made by Broadcom, Inc.
[0035] The egress path comprises depacketizer 262 , decoder 263 , CDIS 266 , DTMF generator 269 , switchboard 210 , echo canceller 235 , and interpolator 220 . The depacketizer 262 receives data packets from a packet network such as, for example packet network 10 of FIG. 1, passing the compressed speech frames to the decoder 263 . The decoder 263 can comprise, for example, the BroadVoice 32 decoder made by Broadcom, Inc. The decoder 263 decodes the compressed speech frames received from the depacketizer 262 and may provide wideband sampled data. If CDIS 266 and DTMF generator support 16 kHz sampled data, the 16 kHz sampled is provided to CDIS 266 and DTMF generator 269 . Again, in one embodiment, where CDIS 266 and DTMF generator 269 require narrowband digitized samples, the wideband data may be downsampled and used by CDIS 266 and the DTMF generator 269 .
[0036] The DTMF generator 269 generates DTMF tones if detected in the data packets received from the sending telephony device 13 a , 13 b , and 13 c . These tones may be written to the wideband data to be passed to switchboard 210 . The wideband data is received by the switchboard 210 , which provides the data to the PXD 215 . The sampled data is passed through the echo canceller 235 and provided to interpolator 220 .
[0037] [0037]FIG. 3 is a more detailed block diagram showing the network services invoked by the network VHD 62 in the voice mode and the associated PXD 60 . In the described exemplary embodiment, the PXD 60 provides two-way communication with a telephone or a circuit-switched network, such as a PSTN line (e.g. DSO) carrying a 64 kb/s pulse code modulated (PCM) signal, i.e., digital voice samples.
[0038] The incoming PCM signal 60 a is initially processed by the PXD 60 to remove far-end echoes that might otherwise be transmitted back to the far-end user. As the name implies, echoes in telephone systems are the return of the talker's voice resulting from the operation of the hybrid with its two-four wire conversion. If there is low end-to-end delay, echo from the far end is equivalent to side-tone (echo from the near-end), and therefore, not a problem. Side-tone gives users feedback as to how loudly they are talking, and indeed, without side-tone, users tend to talk too loudly. However, far-end echo delays of more than about 10 to 30 msec significantly degrade the voice quality and are a major annoyance to the user.
[0039] An echo canceller 70 is used to remove echoes from far-end speech present on the incoming PCM signal 60 a before routing the incoming PCM signal 60 a back to the far-end user. The echo canceller 70 samples an outgoing PCM signal 60 b from the far-end user, filters it, and combines it with the incoming PCM signal 60 a . Preferably, the echo canceller 70 is followed by a non-linear processor (NLP) 72 which may mute the digital voice samples when far-end speech is detected in the absence of near-end speech. The echo canceller 70 may also inject comfort noise which in the absence of near-end speech may be roughly at the same level as the true background noise or at a fixed level.
[0040] After echo cancellation, the power level of the digital voice samples is normalized by an automatic gain control (AGC) 74 to ensure that the conversation is of an acceptable loudness. Alternatively, the AGC can be performed before the echo canceller 70 . However, this approach would entail a more complex design because the gain would also have to be applied to the sampled outgoing PCM signal 60 b . In the described exemplary embodiment, the AGC 74 is designed to adapt slowly, although it should adapt fairly quickly if overflow or clipping is detected. The AGC adaptation should be held fixed if the NLP 72 is activated.
[0041] After AGC, the digital voice samples are placed in the media queue 66 in the network VHD 62 via the switchboard 32 ′. In the voice mode, the network VHD 62 invokes three services, namely call discrimination, packet voice exchange, and packet tone exchange. The call discriminator 68 analyzes the digital voice samples from the media queue to determine whether a 2100 Hz tone, a 1100 Hz tone or V. 21 modulated HDLC flags are present. If either tone or HDLC flags are detected, the voice mode services are terminated and the appropriate service for fax or modem operation is initiated. In the absence of a 2100 Hz tone, a 1100 Hz tone, or HDLC flags, the digital voice samples are coupled to the encoder system which includes a voice encoder 82 , a voice activity detector (VAD) 80 , a comfort noise estimator 81 , a DTMF detector 76 , a call progress tone detector 77 and a packetization engine 78 .
[0042] Typical telephone conversations have as much as sixty percent silence or inactive content. Therefore, high bandwidth gains can be realized if digital voice samples are suppressed during these periods. A VAD 80 , operating under the packet voice exchange, is used to accomplish this function. The VAD 80 attempts to detect digital voice samples that do not contain active speech. During periods of inactive speech, the comfort noise estimator 81 couples silence identifier (SID) packets to a packetization engine 78 . The SID packets contain voice parameters that allow the reconstruction of the background noise at the far end.
[0043] From a system point of view, the VAD 80 may be sensitive to the change in the NLP 72 . For example, when the NLP 72 is activated, the VAD 80 may immediately declare that voice is inactive. In that instance, the VAD 80 may have problems tracking the true background noise level. If the echo canceller 70 generates comfort noise during periods of inactive speech, it may have a different spectral characteristic from the true background noise. The VAD 80 may detect a change in noise character when the NLP 72 is activated (or deactivated) and declare the comfort noise as active speech. For these reasons, the VAD 80 should generally be disabled when the NLP 72 is activated. This is accomplished by a “NLP on” message 72 a passed from the NLP 72 to the VAD 80 .
[0044] The voice encoder 82 , operating under the packet voice exchange, can be a straight 16-bit PCM encoder or any voice encoder which supports one or more of the standards promulgated by ITU. The encoded digital voice samples are formatted into a voice packet (or packets) by the packetization engine 78 . These voice packets are formatted according to an applications protocol and sent to the host (not shown). The voice encoder 82 is invoked only when digital voice samples with speech are detected by the VAD 80 . Since the packetization interval may be a multiple of an encoding interval, both the VAD 80 and the packetization engine 78 should cooperate to decide whether or not the voice encoder 82 is invoked. For example, if the packetization interval is 10 msec and the encoder interval is 5 msec (a frame of digital voice samples is 5 ms), then a frame containing active speech should cause the subsequent frame to be placed in the 10 ms packet regardless of the VAD state during that subsequent frame. This interaction can be accomplished by the VAD 80 passing an “active” flag 80 a to the packetization engine 78 , and the packetization engine 78 controlling whether or not the voice encoder 82 is invoked.
[0045] In the described exemplary embodiment, the VAD 80 is applied after the AGC 74 . This approach provides optimal flexibility because both the VAD 80 and the voice encoder 82 are integrated into some speech compression schemes such as those promulgated in ITU Recommendations G.729 with Annex B VAD (March 1996)—Coding of Speech at 8 kbits/s Using Conjugate-Structure Algebraic-Code-Exited Linear Prediction (CS-ACELP), and G.723.1 with Annex A VAD (March 1996)—Dual Rate Coder for Multimedia Communications Transmitting at 5.3 and 6.3 kbit/s, the contents of which is hereby incorporated herein by reference as though set forth in full herein.
[0046] Operating under the packet tone exchange, a DTMF detector 76 determines whether or not there is a DTMF signal present at the near end. The DTMF detector 76 also provides a pre-detection flag 76 a which indicates whether or not it is likely that the digital voice sample might be a portion of a DTMF signal. If so, the pre-detection flag 76 a is relayed to the packetization engine 78 instructing it to begin holding voice packets. If the DTMF detector 76 ultimately detects a DTMF signal, the voice packets are discarded, and the DTMF signal is coupled to the packetization engine 78 . Otherwise the voice packets are ultimately released from the packetization engine 78 to the host (not shown). The benefit of this method is that there is only a temporary impact on voice packet delay when a DTMF signal is pre-detected in error, and not a constant buffering delay. Whether voice packets are held while the pre-detection flag 76 a is active could be adaptively controlled by the user application layer.
[0047] Similarly, a call progress tone detector 77 also operates under the packet tone exchange to determine whether a precise signaling tone is present at the near end. Call progress tones are those which indicate what is happening to dialed phone calls. Conditions like busy line, ringing called party, bad number, and others each have distinctive tone frequencies and cadences assigned them. The call progress tone detector 77 monitors the call progress state, and forwards a call progress tone signal to the packetization engine to be packetized and transmitted across the packet based network. The call progress tone detector may also provide information regarding the near end hook status which is relevant to the signal processing tasks. If the hook status is on hook, the VAD should preferably mark all frames as inactive, DTMF detection should be disabled, and SID packets should only be transferred if they are required to keep the connection alive.
[0048] The decoding system of the network VHD 62 essentially performs the inverse operation of the encoding system. The decoding system of the network VHD 62 comprises a depacketizing engine 84 , a voice queue 86 , a DTMF queue 88 , a precision tone queue 87 , a voice synchronizer 90 , a DTMF synchronizer 102 , a precision tone synchronizer 103 , a voice decoder 96 , a VAD 98 , a comfort noise estimator 100 , a comfort noise generator 92 , a lost packet recovery engine 94 , a tone generator 104 , and a precision tone generator 105 .
[0049] The de-packetizing engine 84 identifies the type of packets received from the host (i.e., voice packet, DTMF packet, call progress tone packet, SID packet), transforms them into frames which are protocol independent. The de-packetizing engine 84 then transfers the voice frames (or voice parameters in the case of SID packets) into the voice queue 86 , transfers the DTMF frames into the DTMF queue 88 and transfers the call progress tones into the call progress tone queue 87 . In this manner, the remaining tasks are, by and large, protocol independent.
[0050] A jitter buffer is utilized to compensate for network impairments such as delay jitter caused by packets not arriving with the same relative timing in which they were transmitted. In addition, the jitter buffer compensates for lost packets that occur on occasion when the network is heavily congested. In the described exemplary embodiment, the jitter buffer for voice includes a voice synchronizer 90 that operates in conjunction with a voice queue 86 to provide an isochronous stream of voice frames to the voice decoder 96 .
[0051] Sequence numbers embedded into the voice packets at the far end can be used to detect lost packets, packets arriving out of order, and short silence periods. The voice synchronizer 90 can analyze the sequence numbers, enabling the comfort noise generator 92 during short silence periods and performing voice frame repeats via the lost packet recovery engine 94 when voice packets are lost. SID packets can also be used as an indicator of silent periods causing the voice synchronizer 90 to enable the comfort noise generator 92 . Otherwise, during far-end active speech, the voice synchronizer 90 couples voice frames from the voice queue 86 in an isochronous stream to the voice decoder 96 . The voice decoder 96 decodes the voice frames into digital voice samples suitable for transmission on a circuit switched network, such as a 64 kb/s PCM signal for a PSTN line. The output of the voice decoder 96 (or the comfort noise generator 92 or lost packet recovery engine 94 if enabled) is written into a media queue 106 for transmission to the PXD 60 .
[0052] The comfort noise generator 92 provides background noise to the near-end user during silent periods. If the protocol supports SID packets, (and these are supported for VTOA, FRF-11, and VoIP), the comfort noise estimator at the far-end encoding system should transmit SID packets. Then, the background noise can be reconstructed by the near-end comfort noise generator 92 from the voice parameters in the SID packets buffered in the voice queue 86 . However, for some protocols, namely, FRF-11, the SID packets are optional, and other far-end users may not support SID packets at all. In these systems, the voice synchronizer 90 continues to operate properly. In the absence of SID packets, the voice parameters of the background noise at the far end can be determined by running the VAD 98 at the voice decoder 96 in series with a comfort noise estimator 100 .
[0053] Preferably, the voice synchronizer 90 is not dependent upon sequence numbers embedded in the voice packet. The voice synchronizer 90 can invoke a number of mechanisms to compensate for delay jitter in these systems. For example, the voice synchronizer 90 can assume that the voice queue 86 is in an underflow condition due to excess jitter and perform packet repeats by enabling the lost frame recovery engine 94 . Alternatively, the VAD 98 at the voice decoder 96 can be used to estimate whether or not the underflow of the voice queue 86 was due to the onset of a silence period or due to packet loss. In this instance, the spectrum and/or the energy of the digital voice samples can be estimated and the result 98 a fed back to the voice synchronizer 90 . The voice synchronizer 90 can then invoke the lost packet recovery engine 94 during voice packet losses and the comfort noise generator 92 during silent periods.
[0054] When DTMF packets arrive, they are de-packetized by the de-packetizing engine 84 . DTMF frames at the output of the de-packetizing engine 84 are written into the DTMF queue 88 . The DTMF synchronizer 102 couples the DTMF frames from the DTMF queue 88 to the tone generator 104 . Much like the voice synchronizer, the DTMF synchronizer 102 is employed to provide an isochronous stream of DTMF frames to the tone generator 104 . Generally speaking, when DTMF packets are being transferred, voice frames should be suppressed. To some extent, this is protocol dependent. However, the capability to flush the voice queue 86 to ensure that the voice frames do not interfere with DTMF generation is desirable. Essentially, old voice frames which may be queued are discarded when DTMF packets arrive. This will ensure that there is a significant gap before DTMF tones are generated. This is achieved by a “tone present” message 88 a passed between the DTMF queue and the voice synchronizer 90 .
[0055] The tone generator 104 converts the DTMF signals into a DTMF tone suitable for a standard digital or analog telephone. The tone generator 104 overwrites the media queue 106 to prevent leakage through the voice path and to ensure that the DTMF tones are not too noisy.
[0056] There is also a possibility that DTMF tone may be fed back as an echo into the DTMF detector 76 . To prevent false detection, the DTMF detector 76 can be disabled entirely (or disabled only for the digit being generated) during DTMF tone generation. This is achieved by a “tone on” message 104 a passed between the tone generator 104 and the DTMF detector 76 . Alternatively, the NLP 72 can be activated while generating DTMF tones.
[0057] When call progress tone packets arrive, they are de-packetized by the de-packetizing engine 84 . Call progress tone frames at the output of the de-packetizing engine 84 are written into the call progress tone queue 87 . The call progress tone synchronizer 103 couples the call progress tone frames from the call progress tone queue 87 to a call progress tone generator 105 . Much like the DTMF synchronizer, the call progress tone synchronizer 103 is employed to provide an isochronous stream of call progress tone frames to the call progress tone generator 105 . And much like the DTMF tone generator, when call progress tone packets are being transferred, voice frames should be suppressed. To some extent, this is protocol dependent. However, the capability to flush the voice queue 86 to ensure that the voice frames do not interfere with call progress tone generation is desirable. Essentially, old voice frames which may be queued are discarded when call progress tone packets arrive to ensure that there is a significant inter-digit gap before call progress tones are generated. This is achieved by a “tone present” message 87 a passed between the call progress tone queue 87 and the voice synchronizer 90 .
[0058] The call progress tone generator 105 converts the call progress tone signals into a call progress tone suitable for a standard digital or analog telephone. The call progress tone generator 105 overwrites the media queue 106 to prevent leakage through the voice path and to ensure that the call progress tones are not too noisy.
[0059] The outgoing PCM signal in the media queue 106 is coupled to the PXD 60 via the switchboard 32 ′. The outgoing PCM signal is coupled to an amplifier 108 before being outputted on the PCM output line 60 b.
[0060] Referring for a moment to FIG. 2, the functionality of the VHD 205 is responsible for processing the egress packet stream or “voice channel” received from each of the far-end packet voice transceiver systems 200 engaged in a communication session. For example, in a call involving three participants using telephony devices 13 a , 13 b , and 13 d of FIG. 1A, the packet voice transceiver 200 associated with each telephony device may process two voice channels using two VHD 205 s, one for each of the two other telephony devices. The jitter buffer within the decoder 263 of each VHD 205 compensates for irregularities in the arrival of voice packets from the associated far-end packet voice transceiver 200 , by storing speech data sufficient to bridge delays in packet arrival. The amount of memory needed for the jitter buffer in decoder 263 depends upon a number of factors including but not limited to the expected network delay jitter, and the rate at which the contents is consumed by playback. In the case of the packet voice transceiver 200 of FIG. 2, an amount of data equivalent to 300 milliseconds (ms) of speech playback may need to be buffered to avoid audible impairments due to network delay jitter. Depending upon network conditions, a greater or lesser amount of memory may be needed. In addition, the actual amount of jitter buffer space needed for the storage of 300 ms of speech data varies based upon the algorithm used to encode the speech. For example, speech encoded using the International Telecommunications Union—Telecommunications Standards Sector (ITU-T) G.711 standard may require 1200 16-bit words for the storage of 300 ms worth of compressed speech data, and an additional 300 16-bit words for the storage of the associated packet headers. In contrast a voice coder such as the BV 32 encoder by Broadcom, Inc. may require only 600 16 bit words for speech data storage, half that of the G.711 standard.
[0061] [0061]FIG. 4 shows a block diagram illustrating the storage arrangement of a jitter buffer 400 in which the header data and payload data have been stored in separate memory areas having different speed of access, in accordance with the present invention. The jitter buffer 400 may correspond, for example, to the jitter buffer used by the decoder 263 of FIG. 2, or by the voice queue 86 of FIG. 3. As described above, a decoder such as the decoder 263 of FIG. 2 may use a jitter buffer 400 in the processing of each voice channel. In the exemplary embodiment of FIG. 4, the memory space allocated for jitter buffer 400 has been partitioned into two segments, a header memory 406 and a payload memory 407 . In the illustration of FIG. 4, four voice packets have been separated into a header data portion and a payload data portion. The header data portion of each of the four packets is stored in header memory 406 as header data 410 , 430 , 450 , and 470 , while the payload data portion of each of the four packets is stored in payload memory 407 as payload data 420 , 440 , 460 , and 480 , respectively. For ease of understanding, the illustration of FIG. 4 shows the header data and payload data portions corresponding to only four voice packets. An embodiment of the present invention is not limited in this manner, and may be adapted for use with the header data and payload data from a greater or lesser number of packets, without departing from the spirit of the invention.
[0062] The algorithms used in the jitter buffer of decoder 263 of FIG. 2 may include, for example, the tracking of network delay jitter, the detection of packets that are received out of order or lost, and the calculation of the time of release of the packets to the speech decoding algorithms. In performing these and other functions, the jitter buffer and decoder algorithms typically make frequent use of the information contained within the header data 410 , 430 , 450 , and 470 . In addition, algorithm “instance” data are heavily accessed during the operation of the jitter buffer and decoder algorithms. In order to maximize the throughput of those algorithms, an embodiment in accordance with the present invention may store header data 410 , 430 , 450 , and 470 , and algorithm instance data (not shown) in memory that allows the fastest possible access.
[0063] Although the header data 410 , 430 , 450 , and 470 , and algorithm instance data may be needed on a frequent basis, the payload data 420 , 440 , 460 , and 480 may be needed only when decoding of the speech data takes place. The payload data from each network packet represents speech playback of a limited duration, for example, 5 milliseconds. Depending upon the speed of the processor used in the implementation of the decoder 263 , the decoding of the speech data contained within payload data 420 , 440 , 460 , and 480 may take only a small fraction of the time of the actual speech playback. Actual playback of the speech data contained within the payload data 420 , 440 , 460 , and 480 may involve infrequent and limited access to memory, when compared to that for the header data 410 , 430 , 450 , and 470 .
[0064] [0064]FIG. 5 shows a block diagram of an exemplary decoder 500 that may correspond, for example, to the decoder 263 of FIG. 2, in accordance with the present invention. In the illustration of FIG. 5, decoder 500 comprises digital signal processor (DSP) 510 , depacketizer 540 , external memory 547 , and bus 545 . The DSP 510 is further comprised of central processing unit (CPU) 520 and random access memory (RAM) 530 . External memory 547 is partitioned into one jitter buffer for each channel of real-time data supported by the decoder 500 , in this case jitter buffer 550 and jitter buffer 560 .
[0065] In the exemplary decoder 500 of FIG. 5, depacketizer 540 receives packets from egress packet stream 505 . Egress packet stream 50 5 may correspond, for example, to a stream of packets from packet network 10 of FIG. 1. Depacketizer 540 disassembles each received packet and stores the packet contents into jitter buffer 550 or jitter buffer 560 for the associated speech channel. For example, the header data and the corresponding payload data from a received packet may be stored in jitter buffer 550 of external memory 547 , as one of header data 551 , 553 , 555 , and 557 , and one of payload data 552 , 554 , 556 , and 558 , respectively. In the exemplary embodiment shown in FIG. 5, the header data may include, for example, packet sequence numbers, time stamps, and jitter estimates, while the payload data may comprise, for example, compressed speech, music, or video data.
[0066] In the exemplary embodiment shown in FIG. 5, the RAM 530 is arranged to contain header data 531 and algorithm instance data 532 . The RAM 530 may reside on the same integrated circuit (IC) as the CPU 520 , allowing the CPU 520 to have the fastest possible access to the contents of the RAM 530 . Although the RAM 530 is shown as being connected only to the CPU 520 , the RAM 530 may be connected to bus 545 and operate in a dual-port fashion with depacketizer 540 , without departing from the spirit of the present invention. The RAM 530 may be capable of storing, for example, 32 kilobytes of data, and may be limited in size due to the cost of the chip area occupied by the RAM 530 . In an embodiment of the present invention, external memory 547 may be considerably larger that the RAM 530 and may be, for example, several megabytes in size. The speed of access to the external memory 547 by the CPU 520 may be considerably slower than the access to the RAM 530 .
[0067] An embodiment in accordance with the present invention may take advantage of the relatively high speed of the DSP 510 and RAM 530 by keeping the most frequently used information, the header data and the algorithm instance data, within the RAM 530 during the processing of the associated payload data. Due to the limited size of the RAM 530 , an embodiment of the present invention may copy or ‘page’ portions of the slower external memory 547 into the faster RAM 530 , before processing by the CPU 520 . As shown in the illustration of FIG. 5, in an embodiment in accordance with the present invention, the RAM 530 has been arranged with space for header data 531 and algorithm instance data 532 . The header data 551 , 553 , 555 , and 557 of jitter buffer 550 , or header data 561 , 563 , 565 , 567 of jitter buffer 560 is stored within the RAM 530 during processing of the associated payload data by the decoder algorithms. The header data 551 , 553 , 555 , and 557 , and header data 561 , 563 , 565 , and 567 may correspond, for example, to header data 410 , 430 , 450 , and 470 of FIG. 4. The RAM 530 may also contain instance data 532 . Instance data 532 may correspond, for example, to instance data 559 or 569 , and may include, for example, intermediate values of calculations and other algorithm variables used during the decoding of payload data 552 , 554 , 556 , and 558 , and payload data 562 , 564 , 566 , and 568 , respectively.
[0068] In an embodiment in accordance with the present invention, the DSP 510 may periodically perform the decoding functions for multiple speech channels in a round-robin, channel-by-channel fashion. This is because the processing time needed to decode a predetermined amount of the payload data for a channel may be a small fraction of the playback time of the decoded data. For example, let us assume that the speech data for the next channel to be processed is stored in jitter buffer 550 . Immediately prior to processing the speech data for the current channel, the CPU 520 may copy the header data 551 , 553 , 555 , and 557 , and instance data 559 into the header data 531 portion and the instance data 532 portion of the RAM 530 , respectively. The amount of payload data to be processed may represent, for example, 5 ms. of speech playback time. The CPU 520 may then perform the decoding of that portion of payload data 552 , 554 , 556 , and 558 needed for the next interval of speech playback, according to the algorithm used for the current channel. The processing needed to decode 5 ms. of playback may take, for example, 700 microseconds. Upon completion of the processing, the CPU 520 may copy to the header data 551 , 553 , 557 , and 559 of jitter buffer 550 , the header data 531 corresponding to those portions of payload data 552 , 554 , 556 , and 558 that have not yet been processed. It may also copy the current instance data 532 to the instance data 559 of jitter buffer 550 . The CPU 520 may then copy the header data 561 , 563 , 565 , and 567 , and instance data 569 from the jitter buffer 560 to the header data 531 and instance data 532 portions of the RAM 530 , respectively, and execute the decoding algorithm for the channel associated with jitter buffer 560 . 1691 By storing only the header and instance data for the jitter buffer of a channel in the RAM 530 , and storing them in the RAM 530 only during the actual processing of the corresponding payload data, it is possible for an embodiment(s) of the present invention to perform the decoding of a greater number of speech channels than if the entire jitter buffer for all channels were always stored in the RAM 530 . In addition, the CPU 520 may have, for example, several MIPS of computing capacity available to perform other signal processing including, but not limited to, for example, tone generation or detection, echo cancellation or suppression, comfort noise generation, or similar functions. The exact amount of processor capacity available depends upon, for example, the number and size of the jitter buffers implemented, and the types of vocoders in use. In an embodiment of the present invention, a fast DSP 510 with a limited amount of RAM 530 may use larger, less expensive external memory 520 to process a larger number of speech channels that prior art solutions. Although described with respect to the processing of speech channels, the present invention is not limited to its use in speech applications, and may have significant utility with other real-time media streams (e.g., music, video, etc.)
[0069] [0069]FIG. 6 is a flow chart illustrating a method of operating a decoder, in accordance with the present invention. In the flow diagram shown in FIG. 6, two branches are shown, representing two processes that may take place in parallel. The processes illustrated may be performed by one processor, or by a number of processors operating in cooperation, without departing from the spirit of the present invention. In the first branch of FIG. 6, a speech packet for voice channel ‘J’ is received (block 610 ), and the header data portion of the packet is stored in a part of a relatively slower, larger first memory (block 612 ) reserved for the header data of voice channel ‘J’. The payload data or compressed speech portion of the received packet is then stored in a separate part of the slower, larger memory (block 614 ) reserved for the payload data of voice channel ‘J’. Although the exemplary method of FIG. 6 is described with respect to speech, the present invention is not limited in this regard, as the present invention is applicable to other real-time media as well.
[0070] In the second branch of FIG. 6, a decoder such as, for example, decoder 263 of FIG. 2, processes, in sequence, the payload data for each of the supported voice channels. It begins by copying to a relatively faster, smaller memory all header data and algorithm instance data corresponding to the current channel from a part of the slower, larger memory reserved for header data and algorithm instance data of the current voice channel (block 616 ). The decoder algorithm then processes the oldest payload data for the current voice channel that is stored in the faster, smaller memory (block 618 ), using the header data and algorithm instance data stored in the slower, larger memory. Upon completion, the decoder copies header data and algorithm instance data from the faster, smaller memory to the area of the slower, larger memory reserved for the header data and algorithm instance data for the current voice channel (block 620 ). A check is then made whether processing for all channels has been completed (block 622 ). If not all channels have been processed, the decoder copies to the faster, smaller memory all header data and algorithm instance data corresponding to the next voice channel from a part of the slower memory reserved for header data and algorithm instance data of the next voice channel (block 624 ), and the sequence continues until processing for all voice channels is completed.
[0071] Although the present invention has been described above primarily with respect to its application to voice communication systems, it is not limited in this regard. The present invention may also be applied to other real-time communication media as well, e.g. music, video, etc., without departing from its spirit or scope.
[0072] Accordingly, the present invention may be realized in hardware, software, or a combination of hardware and software. The present invention may be realized in a centralized fashion in one computer system, or in a distributed fashion where different elements are spread across several interconnected computer systems. Any kind of computer system or other apparatus adapted for carrying out the methods described herein is suited. A typical combination of hardware and software may be a general-purpose computer system with a computer program that, when being loaded and executed, controls the computer system such that it carries out the methods described herein.
[0073] The present invention also may be embedded in a computer program product, which comprises all the features enabling the implementation of the methods described herein, and which when loaded in a computer system is able to carry out these methods. Computer program in the present context means any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after either or both of the following: a) conversion to another language, code or notation; b) reproduction in a different material form.
[0074] Notwithstanding, the invention and its inventive arrangements disclosed herein may be embodied in other forms without departing from the spirit or essential attributes thereof. Accordingly, reference should be made to the following claims, rather than to the foregoing specification, as indicating the scope of the invention. In this regard, the description above is intended by way of example only and is not intended to limit the present invention in any way, except as set forth in the following claims.
[0075] While the present invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the present invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present invention without departing from its scope. Therefore, it is intended that the present invention not be limited to the particular embodiment disclosed, but that the present invention will include all embodiments falling within the scope of the appended claims.
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A decoder for decompressing real-time media data streams and a method for operating such a decoder is disclosed. The decoder may comprise a relatively larger first memory for storing compressed data and parameters, and a processor for executing a decompression algorithm, the processor having a relatively smaller second memory. The decompression algorithm may be executed on a periodic basis, and the parameters used to select the data to be decompressed may be moved from the second memory to the first memory each time the decompression algorithm executes. An embodiment of the present invention may use slower, less expensive memory to enable it to support a greater number of real-time media streams than prior art solutions. Another embodiment of the present invention may include machine-readable storage having stored thereon a computer program having a plurality of code sections executable by a machine for causing the machine to perform the foregoing.
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BACKGROUND AND SUMMARY OF THE INVENTION
The instant invention relates to a process for piecing back to a spinning device operating with a pneumatic torsion element in which a yarn which is fed back to a drafting mechanism is brought together with a roving, as well as to a device to carry out the process.
In a known process of this type the pair of intake rolls of the drafting mechanism is stopped for the purpose of piecing back when a yarn breakage occurs, so that the roving or the fiber sliver is opened in the drafting zone which follows this pair of intake rolls (DE-OS 3,411,577 and 3,413,894 corresponding with U.S. Pat. Nos. 4,550,560 and 4,545,193, respectively). When the fiber sliver or the roving is fed back to the torsion element for piecing, an irregularity is produced which must be removed from the finished yarn in a further step.
It is therefore the objective of the instant invention to create a process and a device which makes it possible to produce an unobtrusive piecing joint with little expenditure.
This objective is achieved according to the invention in that the roving, after being stopped, is at first released for the piecing process and in that the forward end of the roving which is leaving the drafting mechanism is sucked away until the roving segment which has remained in the drafting mechanism during the prior stoppage of the roving has been taken away, and in that the roving is subsequently fed to the torsion element while being simultaneously brought together and combined with the yarn end. Due to the stoppage of the roving or of the fiber sliver said roving or said fiber sliver is not only discontinued, but its forward end is given an irregular shape which is unsuitable for piecing. Therefore the removal of this affected forward end of the roving or sliver ensures that in piecing a segment with unaffected fiber orientation and length is fed to the torsion element to be combined with the yarn. In this way, even and unobtrusive piecing joints are obtained.
In the sense of the instant invention, roving is understood to be any sliver-like material which can be fed to the torsion element by means of a drafting mechanism, regardless of whether it has little torsion or not. Not only flyer rovings but also card slivers etc. fall therefore into this category.
In order to coordinate the re-starting of yarn torsion in a particularly simple manner with the beginning of yarn draw-off, whereby the length of the piecing joint can be predetermined precisely, it is preferable to draw off the yarn at first through the torsion element without it exerting any twisting action upon the yarn, whereby furthermore, in function of the position of the end of the yarn previously fed-back, the removal of the roving is ended and the feeding of the roving to the torsion element is started, roving and yarn now being submitted together to the twisting effect which now begins.
It is basically sufficient if the yarn and the stretched roving are allowed to run together into the twisting nozzle. However, the longer the common conveying path of roving and yarn between drafting mechanism and torsion element, the better the piecing joint. For this reason provisions can be made in a preferred embodiment of the inventive process for the yarn to be introduced laterally into the closed clamping line of the two output rolls and to be fed necessarily to the torsion element at the speed determined by the rotational speed of the two output rolls.
To prevent the injector effect in the torsion element from provoking uncontrolled draw-off of the yarn after the feeding of compressed air is resumed provisions are made in a preferred version of the process for the yarn which is brought together with the roving to be retained pneumatically and to be furthermore braked mechanically upon resumption of yarn draw-off until part of it is brought together with the roving. The yarn is thus drawn off at a draw-off speed which is dictated mechanically by the winding device or by a pair of draw-off rolls. Beyond this, the yarn in the process of draw-off is controlled between yarn holding device and torsion element until further controlled yarn draw-off is ensured by bringing together the yarn and the roving. Perfect and unobtrusive piecing joints are ensured in this way.
The success of the piecing process does not only depend upon the state of the forward end of the roving but also upon the state of the yarn end. For this reason it is advisable for the end of the yarn which is to be brought together with the roving to be subjected to a pre-treatment before this joining together. This is done preferably by measuring out the yarn to a defined length. The position of the yarn end in the process of being drawn off and which is thus brought to a determined length can then be sensed and can be used as a basis to control further phases of operations in the piecing process, for example in starting roving feeding, in controlling roving suction, in controlling compressed air feeding to the torsion element, etc.
To carry out the process the invention provides for the mouth of a suction nozzle to be brought into action alongside the conveying path of the fiber material between the two outlet rolls of the drafting mechanism and the torsion element. Before piecing the roving is not conveyed through the drafting mechanism but is stopped by the roving stopping device. Depending upon the configuration of the roving stopping device (for example a stoppable pair of intake rolls of the drafting mechanism or a roving clamping device) the forward end of the roving is given a form which makes it impossible to obtain an unobtrusive piecing joint, so that said joint must be removed in a subsequent cleaning process. In order to avoid this, the instant invention provides, after release of the roving, for the affected forward end of the roving to be taken away by means of the suction nozzle mouth which can be activated alongside the conveying path of the fiber material, so that a faultless segment of roving then becomes available for piecing.
To be able to precisely synchronize the moment at which the spinning overpressure in the torsion element is switched on with the moment when yarn draw-off begins and when the negative pressure at the suction nozzle is switched off, the suction nozzle and the torsion element can be connected via a control device to a yarn-end supervision device which is attributed to the pneumatic yarn holding device for this switching off of the negative pressure at the suction nozzle and switching on the overpressure at the torsion element. In this way, a defined transfer of the forward end of the roving from the suction nozzle to the torsion element is achieved, and this is essential for the obtention of good piecing joints.
To exclude uncontrolled yarn movement and uncontrolled start-up thereof through the pneumatic torsion element when the yarn running into the torsion element is being held in a pneumatic yarn holding device, and thereby to avoid irregular piecing joints, this pneumatic yarn holding device is advantageously associated with a yarn brake which acts upon the yarn in the process of draw-off.
In order for the yarn to be fed back without interference, the yarn brake is preferably controllable by means of a controlling device and can be brought by said controlling device into or out of the path of the yarn extending into the yarn holding device. It is advantageous here, in order to ensure faultless guidance of the yarn with respect to the yarn brake, if said yarn brake is located in the yarn holding device which is fashioned as a suction pipe.
However, the quality of the piecing joints is not only influenced by the shape of the forward end of the roving but also by the shape of the yarn end. To ensure that not only a forward end of the roving of perfect quality but also a defined yarn end is available for piecing, a pre-treatment device which can be used on the yarn is suitably provided in a further embodiment of the object of the invention. This pre-treatment device is preferably made in the form of a yarn separating device and is installed in the yarn holding device which is made in form of a suction pipe.
It is customary to carry out piecing with the help of a piecing carriage which can travel alongside the machine and which can be brought to any spinning station at will. In this case the controlling device for piecing is advantageously installed on the piecing carriage, especially the suction nozzle, the yarn holding device as well as a controlling device which can be brought to bear upon the roving stopping device.
To avoid that the pneumatic yarn holding device cover long distances or any distance at all during feed-back of the yarn, the torsion element can, in addition to a first set of compressed air bores with a direction component in the direction of yarn draw-off and which are subjected to compressed air during normal spinning operation, be furthermore associated with a second set of compressed air bores with a direction component in feed-back direction and which are subjected to compressed air during the feed-back of the yarn into piecing position. The torsion element is preferably associated with a first stop which determines the spinning position of the torsion element and which is provided with a first compressed air feeding opening that can be connected to the first set of compressed air openings, as well as with a second stop which determines the threading position and which is provided with a second compressed air feeding opening which can be connected to the second set of compressed air openings.
Preferably each of the two compressed air feeding openings can be provided with a check valve which can be opened by application of the torsion element to the corresponding stop. The second stop is suitably installed on a piecing carriage which can travel alongside the machine and can be brought to any spinning station at will.
To suck away the fly which is produced in continuous spinning operation and to take away a ruptured yarn segment, a preferred embodiment of the object of invention is equipped with a suction nozzle after the torsion element (as seen in spinning direction) near said torsion element and directly next to the yarn conveying path.
The invention ensures reliable piecing and unobtrusive piecing joints with a device of simple design. Only orderly material is presented for piecing, so that no danger exists for the torsion element to become clogged because of non-oriented fibers and consequently for yarn breakage to be provoked.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described in greater detail hereinbelow with reference to embodiments thereof illustrated in the accompanying drawings.
FIG. 1 shows a schematic side-view of a spinning device designed according to the invention;
FIG. 2 shows the spinning device of FIG. 1 in the threading/feed-back phase, in top-view;
FIG. 3 shows a detail of FIG. 2 in a side view;
FIG. 4 shows the part of the inventive device of FIG. 3 in the piecing phase;
FIG. 5 shows a cross-section of a torsion element as well as two stops interacting with the torsion element in its two end positions;
FIG. 6 shows a schematic side-view of a piecing device which is controlled from a service carriage.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The design of the spinning device is first explained through FIG. 1. In the spinning device shown, a roving 1 or a fiber sliver is drawn to the desired yarn thickness by means of a drafting mechanism 2 and is then fed to a pneumatic torsion element 3 where the roving 1 or the fiber sliver is spun into a yarn 10. Yarn 10 is drawn out of the torsion element 3 by means of a pair of draw-off rolls 4 and is fed via a yarn tension compensation hoop 52 to a winding device 5 where the yarn 10 is wound on a bobbin 50. Bobbin 50 is driven by a bobbin roll 51.
The drafting mechanism 2 shown as an example is equipped with four pairs of rolls with rolls 20/200, 21/210, 22/220 and 23/230. Before the rolls 20, 200 of the first pair of rolls and between the rolls 20, 200-21, 210-22, 220 of the first and second as well as of the second and third pair of rolls there are the compressors 201, 211 or 221, preventing excessive spreading of the roving 1 in the drafting mechanism 2. In front of the rolls 21, 210 of the third-before-last pair of rolls as well as in front of the rolls 20, 200 of the pair of rolls upstream from these, the roving clamping devices 241 or 240 are installed and are associated with a joint driving device 24.
The small belts 222 and 223 loop around the two rolls 22, 220.
A suction nozzle 6 is installed next to the conveying path of the fiber material between the rolls 23, 230 of the pair of output rolls of the drafting mechanism 2 and the torsion element 3.
The yarn is imparted false torsion by the compressed air fed to the pneumatic torsion element through a controllable compressed air line 32, said false torsion being removed subsequently to a great extent. For this purpose the shown torsion element is equipped with an injection nozzle 30 and a torsion nozzle 31 after it, carried by a joint holder 33. As the false torsion is imparted and as it is removed the fiber ends are tied into the yarn core while loops are being formed and thus cause a true core torsion to remain in the yarn so that the latter possesses the desired strength.
The holder 33 is supported in a movable fashion so that the torsion element 3 can be brought from a spinning position I into a threading position II and back again (FIG. 2).
The draw-off devices 4 consist as is usual of a driven draw-off roll 40 and of a pressure roll 41 which can be lifted off from said draw-off 40 roll and which is elastically pressed against it. On its way between the torsion element 3 and the draw-off device 4, the yarn 10 is monitored by a yarn monitor 70 which ascertains the presence of spinning tension. The yarn monitor 70 is controllably connected to drive 24 of the roving clamping devices 240 and 241 in order to stop the roving 1 in case of thread breakage, while rolls 20, 21, 22 and 23 of the drafting mechanism 2 continue to run.
Directly next to the path of the yarn, near the torsion element 3, between the latter and the yarn monitor 70, is located the mouth of a suction nozzle 42. It is the role of this suction nozzle 42 to suck away loose fibers which leave the torsion element 3 in form of fly when the spinning operation is interrupted.
When a yarn breakage occurs, the response of the thread monitor 70 and the activation of the roving clamping devices 240, 241 cause the roving 1 to be broken downstream from the roving clamping device 241 due to the continued running of the drafting mechanism 2. This portion of roving 1, which continues to be fed through the drafting mechanism 2 to the torsion element 3 is spun into a short piece of yarn by said torsion element 3 which continues to be subjected to overpressure. Since this short piece of yarn is no longer in contact with yarn 10 which is wound on bobbin 50 as a consequence of the yarn breakage, it is now sucked away through suction nozzle 42.
Simultaneously with the occurrence of a yarn breakage, bobbin 50 is lifted off from the bobbin roll 51 in a known manner (FIG. 3).
To piece the yarn, the swivelling holder 33 brings the torsion element 3 out of spinning position I into threading position II (FIG. 2) where the intake opening of the injection nozzle 30 is located directly in front of the mouth of a pneumatic yarn holding device 8. The spinning overpressure in the torsion element 3 is furthermore switched off.
The yarn end is sucked away in known manner through a swivelling suction pipe 91 (FIG. 6) from the bobbin 50 which is now driven in unwinding direction. As soon as the yarn end inside suction pipe 91 has reached a sufficient length, so that it is securely taken along by the suction pipe 91 even when the latter is swivelled, the yarn holding device 8, fashioned as a suction pipe, is brought from the yarn transfer position indicated by a broken line in FIG. 2 into a yarn receiving position near the outlet opening of the torsion element 3 which is now in threading position II. The yarn 10 which is held by suction pipe 91 is then cut in the known manner, so that it is sucked through the torsion element 3 upon subjection of the pneumatic yarn holding device 8 to negative pressure. Bobbin 50 is then stopped. If the transfer of yarn 10 to the pneumatic yarn holding device 8 is undertaken, reverse rotation of bobbin 50 can also be interrupted earlier and temporarily.
As shown in FIG. 2, the end of yarn 10 which has been fed back is now in a position of readiness alongside to the drafting mechanism 2 which has remained unaffected by the thread monitor 70 and therefore continues to be driven as before, while roving 1 however has been stopped before the drafting zone which is limited by the rolls 21, 210 and 22, 220.
The torsion element 3 is now brought back into its spinning position I (FIG. 4) while the pneumatic yarn holding device 8 is brought out of the yarn receiving position (indicated by a broken line in FIG. 4) shown in FIG. 2 and into the position indicated by an unbroken line in FIG. 4 (yarn transfer position).
The suction nozzle 6 is now subjected to negative pressure. Roving 1 is then released by the roving clamping devices 240 and 241. The forward end of roving 1 has now a different form than during normal spinning operation because of the interruption of said roving 1 which was provoked upon occurrence of the yarn breakage and is not, or only in a limited way, suitable for piecing. For this reason the forward end of roving 1 is dissolved and sucked away by the negative pressure prevailing in suction nozzle 6 until a continuous flow of fiber material is again ensured. The beginning of the drawn roving 1 is then introduced into the torsion element 3 through discontinuance of the negative pressure at the suction nozzle 6 and resumption of overpressure in said torsion element 3 in which said roving 1 is combined with the yarn 10. The suction effect of the airstream produced in the torsion element 3 also draws off yarn 10 from the pneumatic yarn holding device 8. While the yarn end and the forward end of the roving are led together through the torsion element 3 they are combined.
In coordination with the release of roving 1 and with the resumption of air pressure in the torsion element 3 the bobbin 50 is lowered once more upon the bobbin roll 51. The draw-off tension which is now reestablished causes yarn 10 to be drawn into the clamping line of the pair of draw-off rolls 4. In this phase it is possible fo the pressure roll 41 to be lifted off from the driven draw-off roll 40 until the thread monitor registers that spinning tension has been reestablished.
The explained process as well as the described device can be modified in many ways. The replacement of characteristics by equivalents and other combinations thereof come within the framework of the instant invention. For example, instead of a drafting mechanism 2, with four pairs of rolls, it is also possible to use a drafting mechanism with only three or else with more than four pairs of rolls. In the latter instance a roving clamping device, fashioned in the conventional manner, is also installed before the third-before-last pair of rolls and before each pair of rolls before it. The torsion element 3 can (as shown) consist of an injector nozzle 30 and a twisting nozzle 31. For many purposes however, a single nozzle can be sufficient for the torsion element 3.
The roving stopping device can be fashioned in different ways. It is possible, for example, to attribute a coupling to the pair of intake rolls in order to stop roll 20. A roving stopping device in form of a roving clamping device is by comparison simpler in construction while affording equal reliability of operation.
According to the process described in FIGS. 1 to 4 the yarn 10 is brought into such a position by a movement that is axial as well as crosswise to the axis of the torsion element 3 so that the yarn segment which is stretched between the torsion element 3 and the pneumatic yarn holding device 8 is applied to the front of the roll 230 and is introduced from the side into the clamping line of the pair of exit rolls formed by rolls 23, 230 when said roll 230 rotates. The yarn 10 which is fed to the torsion element 3 is thus fed to said torsion element at a speed which is determined by the rotation of said rolls 23, 230. In this way, defined piecing conditions are obtained. To prevent uncontrolled drawing-off of the yarn 10 from the pneumatic yarn holding device 8 before its insertion into the clamping line of the pair of exit rolls, said yarn holding device 8 is equipped with a yarn brake 81 which elastically retains the yarn 10 in the process of being drawn off. Yarn 10 is then drawn off from yarn holding device 8 only at the speed which it is given by bobbin 50 and/or by the pair of draw-off rolls 4. This contributes to increased reliability in the piecing process.
As indicated in FIG. 2, it is often sufficient if the yarn is brought together with the roving 1 only at the entry into the torsion element 3. Uncontrolled drawing-off of the yarn 10 is prevented here too by the yarn brake 81.
In accordance with the embodiment indicated schematically in FIG. 6, the yarn brake 81 is made in form of a braking bolt 810 which is installed in the yarn holding device 8, fashioned as a suction pipe. Said braking bolt can be moved crosswise to the said yarn holding device's longitudinal axis and can be brought into contact with the opposite interior wall of said yarn holding device 8 by its stop surface which is equipped with a retaining clothing 811. Yarn 10 is braked mechanically by this yarn brake 81 until part of said yarn 10 has come into contact with roving 1 and is by then in full piecing process inside torsion element 3.
In order to obtain piecing joints of high quality a further variant of the process provides for the yarn end to be pieced to be given a defined form. For this reason the yarn end is subjected to a pre-treatment of a known type. Here, the yarn end can be untwisted by means of a pre-treatment device 82, it can be napped or simply be brought to a defined length by cutting.
FIG. 6 shows an example in which the pre-treatment device 82 is a yarn cutting device and is installed inside the yarn holding device 8 which is fashioned as a suction pipe.
In order to coordinate the beginning of the spinning process precisely with the resumption of yarn draw-off, provisions are made according to FIG. 6 for the pneumatic yarn holding device 8 to be associated with a yarn-end monitoring device 83. This device, which is only shown schematically, is provided with a light source 830, as shown in FIG. 6, and with a photoelectric cell 831 which is connected to control device 7. This control device 7 is connected to a valve 60 for the control of the underpressure in the suction nozzle 6 as well as to a valve 71 for the control of the overpressure in the torsion element 3. Thus, when the yarn 10 which is drawn off from the pneumatic yarn holding device 8 by the bobbin 50 and/or the draw-off device 4 reaches the light beam projected by light source 830 towards photoelectric cell 831 in the course of piecing, said light beam is released. This causes the control device 7 to switch off the negative pressure at the suction nozzle 6 and to switch on the overpressure at the torsion element 3. Other steps of operation of the piecing process, for example the application of a pressure roll 41 which has previously been lifted off from the driven draw-off roll 40, can be controlled as a function of the position of the yarn end.
According to FIG. 6 the control device 7 is installed on a piecing carriage 9 which can travel alongside the spinning machine to any one of a plurality of spinning stations in order to piece the yarn to the latter, as for example in order to repair yarn breakage.
To minimize construction expenses, all devices which are only needed during the piecing process are installed on this piecing carriage 9. In the embodiment shown in FIG. 6, the most essential of these elements are the suction nozzle 6 which sucks away the forward end of the roving and the pneumatic yarn holding device 8 with all devices which are associated therewith. Furthermore, the control device 7 can be controllingly connected with the driving device 24 for the roving stopping device, as is indicated schematically by a plug-in connection 72. Instead of the indicated plug-in connection 72 (or 710, for the valve 71 which is attributed to the torsion element 3) it is also possible to provide a different type of connection. For example, the piecing carriage 9 is constantly connected to the spinning machine via trailing cables (not shown) and is connected via an appropriate electric switch to each spinning station as it is being serviced.
As FIG. 6 shows, the control device 7 is controllably connected to a bobbin support and drive device 90. This device holds the bobbin 50 at a distance from the bobbin roll 51 during piecing and is turned back so that yarn 10 is fed back into the suction pipe 91. At the same time the bobbin support device and the bobbin drive device can also be elements which are independent of each other. The swivelling drive (not shown) as well as the control valve 910 for the suction pipe 91 are also controllingly connected to the control device 7. In addition to the abovementioned elements, a control valve 80 for the yarn holding device 8 and the drives 810 and 820 for the yarn brake 81 and the pre-treatment equipment 82 are also connected to the control device 7.
Furthermore the torsion element 3 is moved in and out of the spinning position I under control of the control device 7 in a manner which is not shown here.
The operation of the device shown in FIG. 6 is described below:
During piecing, the roving 1 is first of all released in the manner described and is taken away by the negative pressure prevailing at the suction pipe 6 after it leaves the pair of exit rolls constituted by the rolls 23, 230 of the drafting mechanism 2.
Furthermore, the yarn end being retained by the yarn holding device 8 is given a defined form, for example by brushing or by cutting the yarn end to a predetermined length.
In synchronization with this, yarn 10 is drawn off through the torsion element 3 by lowering the bobbin 50 on the bobbin roll 51 and/or by applying the pressure roll 41 on the draw-off roll 40 through the clamping of said yarn which is thus carried out. At this moment the torsion element 3 is however not yet subjected to any overpressure, so that no twisting action is exerted upon the yarn 10. While the yarn is thus drawn off from the yarn holding device 8 the yarn brake 81 is in its braking position in which the yarn is braked between the inner wall of the yarn holding device 8 and the retention clothing 811 which is elastically applied to said inner wall, so that uncontrolled draw-off of yarn 10 from the yarn holding device 8 is not possible.
When the yarn end now reaches the yarn end monitoring device 83, the negative pressure at the suction pipe 6 is switched off and the overpressure at the torsion element 3 is switched on in function of this position being reached, so that the removal of the roving 1 is terminated and so that said roving 1 is instead now fed to the torsion element 3. Due to the twisting effect which now takes place, the yarn end and the drawn roving 1 are now twisted into a yarn 10.
FIG. 5 shows a torsion element 3 which, for reasons of clarity, is shown turned around its longitudinal axis by 90° as compared with the torsion element 3 shown in FIGS. 1 to 4. By its configuration, the torsion element 3 shown in FIG. 5 makes it possible for the yarn holding device 8 to execute merely a very simple movement or to be even stationary. The torsion element 3 in this case, in addition to a first set of compressed air bores 300 and 310 with a direction component in the direction of yarn draw-off (arrow 11), is furthermore provided with a second set of compressed air bores 301 and 311 with a direction component in the direction of feed-back. The first set of compressed air bores 300 and 310 is subjected to compressed air during spinning while the second set of compressed air bores 301 and 311 is subjected to compressed air during the feed-back of yarn 10 into the yarn holding device 8. Since in an embodiment with a torsion element 3 of such design, with two sets of compressed air bores 300/310 and 301/311, the yarn holding device 8 can be at a relatively great distance from the torsion element 3 in threading position II for the threading of the fed-back yarn, whereby the yarn 10 extends at a favorable angle to the torsion element 3 after the torsion element 3 has been returned into its spinning position I, no complicated drives for the yarn holding device 8 are needed.
According to FIG. 5 the torsion element 3 is associated with two stops 34 and 35 of which the stop 34 determines the spinning position I and the other stop 35 determines the threading position II of the torsion element 3. This second stop 35 can here be installed on the piecing carriage 9 so that it is attributed to the spinning station being serviced during piecing, so that a separate stop 35 need not be provided for each spinning station. Each stop 34 and 35 is equipped with an intake opening 340 or 350 for compressed air. The intake opening 340 for compressed air is here installed in the stop 34 so that it is connected to the compressed air openings 300 and 310 of the torsion element 3 when the latter is in spinning position I, while the intake opening 350 for compressed air is installed in the stop 35 so that it matches the compressed air openings 301 and 311 when the torsion element 3 is in threading position II.
The compressed air is here controlled by means of a valve 71 as shown in FIG. 6.
In the embodiment shown in FIG. 5, each intake opening 340 or 350 for compressed air is equipped with a check valve 341 or 351 which is opened when the torsion element 3 is applied against the corresponding stop 34 or 35, and closes automatically when said torsion element 3 is lifted off from said stops 34 or 35. It is thus no longer necessary to provide for separate control through control device 7 (as is the case with valve 71 shown in FIG. 6).
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For piecing to a spinning device operating with a pneumatic torsion element, yarn is fed back through the torsion element into a readiness position alongside a drafting mechanism, while the roving is stopped before the end of the drafting zone. The roving is then released, whereby the forward roving end which is leaving the drafting mechanism, and which typically is rendered unsuitable for piecing due to stoppage of the roving, is sucked off. When a roving segment which remained in the drafting mechanism during the prior roving stoppage has been taken away, the roving and the yarn end are brought together and are simultaneously fed to the torsion element so as to be combined. To carry out this process, the drafting mechanism preferably includes before the end of its drafting zone at least one roving stopping device which may be controllable with feedback from a yarn monitor located adjacent the path of yarn being conveyed to a yarn take-up mechanism, such as a bobbin. Furthermore, a suction nozzle can be selectively situated and activated between a pair of exit rolls of the drafting mechanism and the torsion element, for removing controllably the forward end of a roving rendered unsuitable for piecing by stoppage of such roving.
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This application is a continuation of U.S. application Ser. No. 09/445,174 filed on Apr. 24, 2000, now U.S. Pat. No. 6,733,966. The specification of U.S. application Ser. No. 09/445,174 is hereby incorporated by reference.
This application asserts priority of international application numbers PCT/NL98/00325, filed on Jun. 3, 1998, and EP97201700.8, filed on Jun. 4, 1997. The specifications of PCT/NL98/00325 and EP97201700.8 are hereby incorporated by reference.
The present invention relates generally to the field of human genetics. In particular the invention relates to methods and means (diagnostic test kits) for studying the predisposition for certain types of cancers often having a hereditary component and more specifically to the detection of a specific type of germline mutations in genes involved or associated with certain types of hereditary cancers, in particular the (human) BRCA1 gene, which will predispose to breast and ovarian cancer. In addition, the invention reveals a molecular genetic mechanism that may have mediated the genesis of these mutations, in particular the role of Alu repetitive DNA elements present in the intronic regions of BRCA1. The invention further relates to somatic mutations of this type in the BRCA1 gene in human breast and ovarian cancer, and their use in the diagnosis and prognosis of human breast and ovarian cancer.
The invention also relates to the screening of this type of BRCA1 mutations in human genomic DNA, as part of clinical protocols for the diagnosis of inherited predisposition to breast and ovarian cancer.
BACKGROUND OF THE INVENTION
Breast cancer is the most common malignancy among women in the Netherlands, with a cumulative risk by age 85 of one in 11. The strongest epidemiological risk factor for the disease is a positive family history. Depending on the age of diagnosis and occurrence of bilateral disease in the index case, first degree relatives may have a relative risk of up to 10 for developing breast cancer. In the US population, 6 to 19% of women with breast cancer have at least one affected relative at the time of diagnosis [1], but not all of them are expected to be true genetic cases as the high incidence of breast cancer in the general population will inevitably cause some coincidental familial clustering. In an attempt to stratify the two classes, criteria to define truly inherited breast cancer have been proposed [2]. Such cases are characterized by early age of onset (premenopausal), excess of bilaterality, and clear paternal or maternal transmission with an autosomal dominant mode of inheritance. Approximately 5% of all cases comply with these criteria, while another 13% are classified as familial clustering [3]. Since early age of onset appears to be a hallmark of hereditary breast cancer, one may suspect that among these cases the genetic component is much higher. Indeed, up to 35% of cases diagnosed under the age of 30 are expected to be genetic [4]. No such data are available for the Dutch situation, and little or none of this has been confirmed at the molecular genetic level.
Linkage analysis of early-onset breast cancer families localized BRCA1 to the long arm of chromosome 17 [5]. Further analyses of additional families revealed that women inheriting a mutant allele of BRCA1 are also at increased risk for ovarian cancer [6, 7]. Overall, approximately 45% of all families in which breast cancer is the predominant malignacy are due to BRCA1, as are over 80% of all families with both breast and ovarian cancer [6, 8]. Female mutation carriers have been estimated to have an 87% risk to develop breast cancer before the age of 70, and 63% risk to develop ovarian cancer before the age [7]. However, significant evidence for ovarian cancer risk heterogeneity was obtained, indicating the existence of at least two classed of BRCA1 mutations; one conferring a high risk to both breast and ovarian cancer, and one conferring a high risk to breast cancer, but only a moderate risk to ovarian cancer, with the former comprising approximately 26% of all BRCA1 mutations [9]. The gene frequency of BRCA1 has been estimated to be 1 in 833 women [10]. This would imply that 1.7% of all breast cancer patients diagnosed between age 20 and 70 are carrier of such a mutation.
The gene structure of BRCA1 was found to consist of 22 coding exons spanning >80 kb of genomic DNA [11], and encoding a 7.8 kb transcript [12]. An unusually large exon 11 of 3.4 kb comprises 61% of the coding domain. Over 900 mutations in BRCA1 have been published to date and compiled into an electronically accessible database [13]. Several characteristics stand out [14]. First, they are nearly ubiquitously distributed over the gene. Second, >85% of the mutations in the database lead to premature termination of protein translation. These include basepair substitutions leading to a stop codon, small insertions and deletions (of 1 to 40 basepairs) leading to a frame-shift, or splice-site mutations leading to deletions of complete exons and frame shifts. That these changes presumably inactivate gene function is supported by the finding that the great majority of breast and ovarian tumors that develop in BRCA1 mutation carriers show loss of the wildtype allele [15]. The relevance in terms of cancer predisposition of the missense mutations remains a matter of debate. Some of them appear rare polymorphic variants, as they are also observed in control samples. Others seem to affect critical residues, such as the cysteines in the amino-terminal ring finger domain [12], which are conserved in the mouse Brca1 sequence [16]. Third, a number of mutations have been found repeatedly, reducing the number of distinct mutations to about 150. Two of these, the 185delAG mutation and the 5382insC mutation, each represent approximately 11% of all mutations thus far reported [14]. Reconstruction of the haplotypes bearing some of the most common mutations has provided strong evidence that they have either a single or a few common ancestors and may have been present in the population already for several centuries [17-19]. Consequently, the incidence of specific mutations is strongly dependent on the population from which the breast cancer families were ascertained. Thus the 185delAG mutation was picked up mainly in families of Ashkenazi-Jewish origin [20]. The extent of the founder-effect was highlighted by the finding that approximately 1% of all Ashkenazi Jews (i.e. regardless of a positive breast cancer family history) are carrying this mutation [21,22], 8 times that of the incidence of all mutations together in the general population [10]. Specific mutations have also been recurrently detected in breast cancer families of Swedish, British, Italian, and Austrian origin [18,23-26].
Despite the vast number of BRCA1 gene changes detected to date, there remains a discrepancy between the proportion of BRCA1 mutations predicted by linkage studies [6,8], and the actual prevalence established by mutation analysis, among breast cancer families derived from a variety of ethnic backgrounds [27-31]. In general, this is explained in two ways: either a substantial number of mutations have been missed by the applied mutation screening methodology, or the genetic heterogeneity of hereditary breast cancer is significantly greater than hitherto expected.
Relatively little information of predictive value can be gleaned from the existing data. In one set of 35 kindreds with proven BRCA1 mutations from the United Kingdom, the ovarian cancer risk heterogeneity as predicted from linkage studies could be confirmed [25]. Mutations occurring before codon 1435 conferred a significantly higher ovarian cancer risk than those occurring after this point. While this is consistent with earlier predictions based on linkage analysis [9], the current mutation distribution is at odds with the predicted lower frequency of these alleles. In addition, the expressivity of BRCA1 displays considerable inter-family variability. For example, the 185delAG mutation was detected in families with early-onset breast cancer and ovarian cancer, or late-onset breast cancer without ovarian cancer [32]. Clearly, other factors influence the expression of the phenotype, and some of those might be genetic, others environmental. Of note, BRCA1 carriers who have a rare allele at the HRAS1 minisatellite locus were recently shown to be at a 2.8-fold increased risk for ovarian cancer relative to those carriers who had common alleles at HRAS1 [33]. However, a firm establishment of the full spectrum of BRCA1 gene changes in the population is pivotal for a more formal analysis of this matter.
An intriguing feature of BRCA1, and unexpected in the light of Knudson's two-hit inactivation theorem for tumor suppressor genes, is that somatically acquired mutations are extremely rare in ovarian tumors [34-38] and have in fact not yet been detected in 135 breast tumors [39-40]. This might indicate that inactivation of BRCA1 is not selected for during tumorigenesis of the non-inherited form of breast cancer. BRCA1 expression might be critical only during certain stages of tissue development, e.g., during puberty when the breast undergoes its final differentiation into a potential milk-producing gland [39]. However, others have argued that the mechanism of inactivation might be different from that seen in inherited cases [41].
SUMMARY OF THE INVENTION
The present invention now reveals that the unusual high concentration of Alu-elements in the BRCA1 gene intronic regions [11] favors the induction of large genomic deletions and inversions in a situation of increased genomic instability although other mechanisms leading to these mutations may also play significant roles. The present invention thus provides a diagnostic test kit (and means and methods) for determining mutations, especially deletions of relatively large stretches of nucleotides in genes associated with hereditary types of cancer, in particular such mutations (deletions of relatively large stretches of nucleotides) in the BRCA1 gene. Such mutations are difficult, if not impossible, to detect by the currently PCR-based approach (if their occurrence or the site thereof is unknown) using genomic DNA as template, which has been most widely applied to establish the current mutation spectrum of BRCA1.
The present invention thus provides a diagnostic test kit for detecting the presence of or predisposition for e.g. breast cancer, whereby a means is provided for detecting a deletion of a stretch of nucleotides from a BRCA 1 gene in a sample. Now that it is known that such mutations occur, it is within the skill of the art to arrive at means to determine the presence of these mutations, either the ones disclosed herein or similar mutations. Such means may include hybridization of a probe flanking both sides of the deletion, or using two probes on either side of the deletion and amplifying the stretch in between, another way may be lack of hybridization, when using a probe hybridizing to a deleted part, etc. Yet another way may be lack of amplification between one or more sets of primers targeted at or near a deleted region. This already implicates that typically multiplex PCR approaches are very suitable. Also exon-connection PCR is a very suitable approach for use in the present invention. The techniques mentioned above are well known in the art and need no further explanation. Since mutations as disclosed herein may occur in one allele only, quantitative methods are often preferable. It is of course clear that the diagnostic test kit should provide all other necessary means for determining the presence or absence of the mutations, such as buffers, detection means (possibly labels or markers), etc. A convenient diagnostic test kit according to the invention apart from amplification methods such as PCR, NASBA and the like is a diagnostic test kit whereby the means comprise the necessary elements for southern blotting. The deletions to be detected are typically relatively large stretches of nucleotides, particularly of a size which when subjected to PCR or similar amplification techniques would not be amplified under normal reaction conditions because of their length. Typically the deletion comprises one or more exons of the BRCA1 gene or a frameshift and/or a termination codon. An exemplified deletion that is a good marker for the predisposition for cancer is the deletion which comprises at least a major part of exon 22.
Another exemplified deletion that is a good marker for the predisposition for cancer is the deletion which comprises at least a major part of nucleotides 1396-1662.
Another exemplified deletion that is a good marker for the predisposition for cancer is the deletion which comprises at least a major part of exons 13-16.
Another exemplified deletion that is a good marker for the predisposition for cancer is the deletion which comprises at least a major part of exon 13.
An exemplified deletion that is a good marker for the predisposition for cancer is the deletion which comprises a stretch of nucleotides between two ALU-elements. This kind of deletion ties in very nicely with a suggested mechanism of the origin of these mutations and the same may also be found in other genes involved in cancer and having many of these elements.
Thus the invention further provides a probe for use in a diagnostic test kit according to invention comprising a nucleic acid sequence which is a fusion of two (complementary sequences of) ALU elements, in particular of the BRCA1 gene. In general the invention thus provides a probe for use in a diagnostic test kit according to the invention, which is a fusion product of two sequences adjacent to the site of a deletion of a stretch of nucleotides.
Also provided is a method for determining the presence in a sample of a nucleic acid derived from a BRCA1 gene having a deletion of a stretch of nucleotides, comprising contacting said sample with at least one probe which alone or together with other means is capable of distinguishing between BRCA1 genes having said deletion and BRCA1 genes not having said deletion, allowing for possible hybridization between said probe and said nucleic acid and identifying the hybridization product.
Specific embodiments of the invention will be explained in detail below.
DETAILED DESCRIPTION OF THE INVENTION
The present invention in one of its embodiments, which has been described in detail in the experimental part provides a description and detection in human genomic DNA of large genomic deletions in BRCA1. In addition, the invention shows involvement of the Alu-repeat elements, present at high frequency in the intronic regions of BRCA1 [11], in generating a number of these deletions. The invention also contemplates the frequency of these deletions in the Dutch population, and their descendance from a common ancestor.
We have found that the mutation spectrum of BRCA1 as resolved up to this point [13,42] has been biased by PCR-based mutation-screening methods such as SSCP, the protein truncation test (PTT), and direct sequencing, using genomic DNA as template. We describe as examples thereof two large genomic deletions, which are not detected by these approaches, and which together comprise 38% of all BRCA1 mutations found in a sample of 170 Dutch breast cancer families [43,44]. One deletion removes 510 basepairs (bp) including exon 22 ( FIG. 1 ) and was found 8 times. The other deletion removes 3835 bp including exon 13 ( FIG. 2 ) and was found 4 times.
The haplotypes of the 8 families with the exon 22 deletion were reconstructed by typing 3 intragenic markers (D17S855, D17S1322, D17S1323) and 2 flanking markers (THRA1 and D17S1327). These haplotypes were completely concordant for the intragenic markers in at least 7 families, and the haplotype conservation extended proximally to THRA1, and distally to D17S1327, in at least 5 families, to comprise a genetic region of approximately 2 cM. The haplotypes of the 4 families with the exon 13 deletion were reconstructed in a similar way. These haplotypes were completely concordant for the intragenic markers in at least 2 families, and the haplotype conservation extended proximally to THRA1, and distally to D17S1327, in all 4 families, to comprise a genetic region of approximately 2 cM.
Molecular characterization of the deletions revealed that the exon 22 deletion starts in intron 21 and ends within the most upstream copy of three head-to-tail arranged Alu-elements in intron 22. A 17-bp imperfect homology to the intron 22 Alu-element was found at the 5′ deletion breakpoint ( FIG. 3 ) The 3′ breakpoint is closely flanked on either side by two 25-bp sequences strongly homologous to the Alu core-sequence implied to stimulate recombination [45].
The exon 13 deletion starts in intron 12 in an Alu-element (112 bp from the 5′ end) and ends in intron 13 in a region which shares very high homology to this element ( FIG. 4 ). Both the 5′ and the 3′ breakpoint are closely flanked on either side by sequences strongly homologous to the 26-bp Alu core-sequence implied to stimulate recombination [45].
The current invention facilitates the design of PCR-based strategies (now that the presence of this kind of mutations is known) to identify the heterozygous presence of the deletions in human genomic DNA. Oligonucleotide primers can be designed so to immediately flank the deletion breakpoints, and allow the specific amplification of a deletion-junction fragment as a diagnostic endpoint. Given the size of the deletions, the wildtype BRCA1 genomic sequence would remain refractory to PCR-amplification under most standard reaction conditions. PCR-based diagnosis is an essential requirement to scale up throughput in the screening for these mutations.
The current invention also pertains to the molecular mechanism which may have generated the genomic deletions in the BRCA1 gene, especially since this needs to be viewed in a broader sense in that the same kind of phenomenon may be picked up in other genes or in the same gene, but not having anything to do with the inheriting kind of cancer.
The current invention thus also pertains to the role of BRCA1 mutations in non-inherited or sporadic breast cancer.
EXAMPLES
The exon 22 deletion was revealed by Southern blot analysis of genomic DNA digested with either HindIII or BglII. As probe we used p1424, which contains ˜ 1-kb cDNA-derived segment from exons 14-24. A carrier of the exon 22 deletion shows aberrant bands of 9.3 kb in the HindIII digest and of 6.7 kb in the BglII digest.
The exon 13 deletion was revealed by Southern blot analysis of genomic DNA digested with either HindIII or BglII. As probes we used either p11 or p1424, which contain ˜ 1-kb cDNA-derived segments from exon 11 and exons 14-24, respectively. A carrier of the exon 13 deletion shows an aberrant band of 6.4 kb in the HindIII pattern obtained with probe p1424 and of 14 kb in the BglII pattern obtained with probe p11.
To further characterize these deletions, we used intronic amplimers to obtain PCR-products from genomic DNA, specifically containing the deletion-junction fragment. Amplimers flanking exon 22 generated an aberrant genomic fragment of 1.4 kb in DNA samples carrying the exon 22 deletion, which turned out to contain a 510-bp deletion relative to the wildtype sequence ( FIG. 3 ). The deletion affecting exon 22 removes the bases 79505-80014 (510 bp) as listed in the genomic sequence of BRCA1 (Genbank accession nr. L78833). As a result, 74 basepairs, corresponding to exon 22, are missing in the Processed mRNA-transcript (bases 79543-79615 in Genbank accession nr. L78833).
Amplimers flanking exon 13 generated an aberrant genomic fragment of 2.7 kb in DNA samples carrying the exon 13 deletion, which turned out to contain a 3835 bp deletion relative to the wildtype sequence ( FIG. 4 ). The deletion affecting exon 13 removes the bases 44514-48348 (3835 basepairs) as listed in the genomic sequence of BRCA1 (Genbank accession nr. L78833). As a result, 172 basepairs, corresponding to exon 13, are missing in the processed mRNA-transcript (nucleotides 46156-46327 in Genbank accession nr. L78833).
We examined 142 breast cancer families in which thusfar no BRCA1 or BRCA2 mutation had been found (refs. 43,44 and our unpublished results) for the presence of the exon 13 and exon 22 deletions. They were found in 4 and 8 families, respectively. Together with previous mutation screening results, using PTT and direct sequencing [44], these deletions thus comprise 12/32 (38%) of all families in which a BRCA1 mutation has been detected to date. Three intragenic and 2 flanking markers were used to reconstruct the disease haplotype for each of the research families carrying either the 510-bp or 3.8-kb deletion. Strong conservation of allele-lengths was observed at the intragenic loci among the haplotypes carrying the same deletion, in agreement with their descent from a common ancestor.
The haplotype in the Dutch population that carries the 510-bp deletion around exon 22 is characterized by a 155-bp allele at the microsatellite marker D17S855 in intron 20, a 122-bp allele at microsatellite marker D17S1322 in intron 19, and a 151-bp allele at microsatellite marker D17S 1323 in intron 12. The haplotype in the Dutch population that carries the 3835-bp deletion around exon 13 is characterized by a 151-bp allele at D17S855, a 122-bp allele at D17S1322, and a 151-bp allele at D17S1323 in intron 12. The primer sequences used to detect these alleles are: for D17S 1322: Forward (F) 5′ CTAGCCTGGGCAACAAACGA 3′ (SEQ. ID. NO.: 1 and Reverse (R) 5′ GCAGGAAGCAGGAATGGAAC 3′ (SEQ. ID. NO.: 2); for D17S855: F 5′ GGATGGCCTTTTAGAAAGTGG 3′ (SEQ. ID. NO.: 3) and R 5′ ACACAGACTTGTCCTACTGC 3′ (SEQ. ID. NO.: 4); for D17S1323: F 5′ TAGGAGATGGATTATTGGTG 3′ (SEQ. ID. NO.: 5) and R 5′ AAGCAACTTTGCAATGAGTG 3′ (SEQ. ID. NO.: 6). PCR conditions have been described elsewhere [44].
Detection of the Mutations
Isolation of genomic DNA and total RNA from freshly taken blood samples, and preparation of first-strand cDNA by reverse transcription, has been described [43].
cDNA Analysis to Detect the Exon 13 Deletion.
Exons 12-24 were amplified from first-strand cDNA products obtained by reverse transcription using the following primers for the first PCR: F 5′ TCACAGTGCAGTGAATTGGAAG 3′ (SEQ. ID. NO.: 7) and R 5′ GTAGCCAGGACAGTAGAAGGACTG 3′ (SEQ. ID. NO.: 8). The obtained PCR-products were used as template for a second PCR of exons 12-24 using nested primers (F 5′ GAAGAAAGAGGAACGGGCTTGG 3′ (SEQ. ID. NO.: 9) and R 5′ GGCCACTTTGTAAGCTCATTC 3′ (SEQ. ID. NO.: 10)). PCR conditions were as described previously [43]. Five μl of the final PCR products are analysed on a 1% agarose gel.
cDNA Analysis to Detect the Exon 22 Deletion.
Exons 12-24 were amplified from first-strand cDNA products obtained by reverse transcription using the following primers for the first PCR: F 5′TCACAGTGCAGTGAATTGGAAG 3′ (SEQ. ID. NO.: 7) and R 5′ GTAGCCAGGACAGTAGAAGGACTG 3′ (SEQ. ID. NO.: 8). The obtained PCR-products were used as template for a second PCR of exons 20-24 using nested primers (F 5′ AACCACCAAGGTCCAAAGC 3′ (SEQ. ID. NO.: 11) and R 5′ GTAGCCAGGACAGTAGAAGGACTG 3′ (SEQ. ID. NO.: 12)). PCR conditions were as described previously [43]. Five μl of the final PCR products are analysed on a 1% agarose gel.
Genomic PCR of the 3835-bp deletion spanning exon 13. A PCR reaction of 50 μl contains 200 ng of genomic DNA, 10 pmol primers (F 5′ TAGGAGATGGATTATTGGTG 3′ (SEQ. ID. NO.: 5) and R 5′ TACGTGGGTTCAACTGAAGC 3′ (SEQ. ID. NO.: 13)), 0.75 Units Amplitaq Taq polymerase (Perkin-Elmer-Cetus), and 5 μl of 10× ITP/BSA buffer (500 mM KCl 100 mM TRIS-HCl pH 8.4, 25 mM MgCl 2 , 2 mg/ml BSA, 2 mM dNTPs). This mixture is heated at 94° C. for 5 minutes, followed by 35 cycles of PCR (at 94° C. for 45 seconds, at 52° C. for 1 min. and at 72° C. for 2.5 mm on a Perkin-Elmer-Cetus DNA thermal Cycler). The PCR is concluded by an incubation at 72° C. for 6 minutes. Five μl of the PCR products are analysed on a 1% agarose gel.
Genomic PCR of the 510-bp deletion spanning exon 22. A PCR reaction of 50 μl contains 300 ng of genomic DNA, 10 pmol primers (F 5′ TCCCATTGAGAGGTCTTGCT 3′ (SEQ. ID. NO.: 14) and R 5′ ACTGTGCTACTCAAGCACCA 3′ (SEQ. ID. NO.: 15)), 0.75 U Amplitaq Taq polymerase (Perkin-Elmer-Cetus), 5 μl Optiprime buffer #6 (Stratagene) and 0.1 mM dNTPs. Thermal cycles are as described for the deletion of 3.8 kb. Five μl of the PCR products are analysed on a 1.5% agarose gel.
Southern Analysis.
Five μg of genomic DNA is digested with either the restriction endonuclease BglII or HindIII. Agarose gels (0.8%) are run at 30V for 16 hr in TAE buffer (40 mM Tris-HAc pH 8.3, 1 mM EDTA). Procedures for denaturing, and transferring the separated DNA to nylon membranes (Hybond N+, Amersham) have been described [46]. As probes we used PCR-products obtained from a clone containing the complete BRCA1-cDNA, and purified by using the QIAquick PCR Purification Kit from QIAGEN. Probe-11 (p11) derives entirely from exon 11 and was obtained with the primers F 5′ GAAAAAAAAGTACAACCAAATGCC 3′ (SEQ. ID. NO.: 16) and R 5′ AGCCCACTTCATTAGTACTGGAAC 3′ (SEQ. ID. NO.: 17), and probe-1424 (p1424) contains exons 14-24 and was obtained with the primers F 5′ TACCCTATAAGCCAGAATCCAGAA 3′ (SEQ. ID. NO.: 18); and R 5′ GGCCACTTTGTAAGCTCATTC 3′ (SEQ. ID. NO.: 19). Purified fragments were labelled using the Megaprime DNA labelling System from Amersham according to suppliers protocols. Hybridizations were carried out at 65° C. in 125 mM Na2HPO4.2H2O, 7% SDS, 10% PEG-6000, 1 mM EDTA. Final washing was in 45 mM NaCl, 4.5 mM Na-citrate pH 7.0, 0.1% SDS, at 65° C. for 30 minutes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 . Schematic representation of the genomic deletion spanning exon 22 of BRCA1. The intronic regions are drawn to scale relative to one another, and the exonic region are drawn to scale relative to one another, but not to intronic regions. The positions of the restriction endonucleases HindIII and BglII, used in Southern blot analysis, are indicated. The arrows indicate the presence and orientation of an Alu-element.
FIG. 2 . Sequence of exon 22 (uppercase) and its flanking intron-sequence (lower case) (SEQ. ID. NO.: 20). The numbers refer to the genomic sequence of BRCA1 (Genbank accession nr. L78833). Starting and ending positions of the 510-bp deletion are indicated by hooked arrows and affect positions 79505-80014. The first 241 bp of an Alu-element are depicted in italics, and the boxed sequences are imperfect copies (1 and 5 mismatches, respectively) of a common 26-bp core sequence involved in recombinations leading to gene rearrangements in the LDLR gene [45]. A stretch of 17 bp at the 5′ junction of the deletion is homologous to a 19-bp stretch 37 bp upstream of the 3′ deletion-breakpoint (underlined with arrows).
FIG. 3 . Schematic representation of the genomic deletion spanning exon 13 of BRCA1. The intronic regions are drawn to scale relative to one another, and the exonic region are drawn to scale relative to one another, but not to intronic regions. The positions of the restriction endonucleases HindIII and BglII, used in Southern blot analysis, are indicated. The arrowheads indicate the presence and orientation of an Alu-element.
FIG. 4 . Aligned sequences of intronic regions flanking exon 13 (SEQ. ID. NOS.: 21 and 22), and of the deletion-junction fragment (Jnctn) (SEQ. ID. NO.: 23). The upper sequence of each alignment corresponds to intron 12 sequences (SEQ. ID. NO.: 21), the lower sequence intron 13 sequences (SEQ. ID. NO.: 22). The numbers refer to the genomic sequence of BRCA1 (Genbank accession nr. L78833). The boxed sequence indicates the 10 bp where the recombination took place that led to the deletion of 3835 bp. The intron 12 sequence depicted here represents the first 180 bp of an Alu-element. The intron 12 region 44481-44551 shares an 85% identity with the intron 13 region 48316-48386. The underlined sequences are imperfect copies of a common 26-bp core sequence involved in recombinations leading to gene rearrangements in the LDLR gene [45].
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The present invention relates generally to the field of human genetics, and more specifically to the detection of a specific type of germline mutations in the BRCA1 gene, which will predispose to breast and ovarian cancer. In addition, the invention relates to the molecular genetic mechanism that may have mediated the genesis of these mutations, in particular the role of Alu repetitive DNA elements present in the intronic regions of BRCA1. The invention further relates to somatic mutations of this type in the BRCA1 gene in human breast and ovarian cancer, and their use in the diagnosis and prognosis of human breast and ovarian cancer. The invention more particularly relates to the screening of this type of BRCA1 mutations in human genomic DNA, which are useful for the diagnosis of inherited predisposition to breast and ovarian cancer.
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This is a continuation of application Ser. No. 751,337 filed Aug. 29, 1991 now U.S. Pat. No. 5,259,166 issued Nov. 9, 1993.
The present invention relates to the art of converting a pitched roof into a potable water gathering system and more particularly to a method of applying a water gathering and channeling roof covering onto the upper roof of a building, which covering is formed from a metal that is inert and neutral to rain water.
INCORPORATION BY REFERENCE
The present invention relates to a system of roofing employing elongated preformed strips of metal having opposite edges formed into matching standing seam elements so that the strips can be placed in side-by-side relationship and the standing seam elements can be folded or formed into an upstanding seam between the strips so that water can pass downwardly between the standing seams as it is gathered by the roof. This system has been popularized and is generally associated with Follansbee Steel, a division of The Louis Berkman Company located in Steubenville, Ohio and is shown in several patents such as Boyd U.S. Pat. Nos. 4,934,120; 4,982,543; 4,987,716; 5,001,881 and 5,022,203. These patents are incorporated by reference herein to show the standing seam type roofing system to which the present invention is directed.
BACKGROUND
In many areas of the world, particularly tropical areas, the potable water supply system utilizes roof structures for gathering rain water which is directed to a collecting reservoir. Use of such systems are increasing worldwide. In certain areas of the world, population increases coupled with primitive or inadequate sewage treatment facilities have toxified the aquifer rendering well water unfit for consumption. In other areas, toxic wastes have poisoned the acquifer and/or underground wells again rendering well water unfit for consumption. In such areas, roof structures, particularly roof structures for large buildings, form an integral part of the potable water system.
Slate, shale, tile and bituminous roofing systems are unsuitable for collecting and directing potable water from the roofs of various buildings to collecting reservoirs. Besides water contamination, such systems are unsuitable as roofing structures for certain climates. Metal roofing systems are the only roofing systems suitable for use in all climates throughout the world.
The most common, long term, durable and easily assembled roof system which can be used for channeling water along a pitch roof of a large building is the Follansbee roofing system which is commonly known as the FRS system. One of the essential features of the FRS system, as currently produced, is the use of terne coated steel as the roofing material. The terne coated steel employed in the FRS system is a type 304 stainless steel coated on both sides with a terne alloy of 20% tin, 80% lead. The terne coated steel has inherent characteristics which assure functional longevity of the roof. Among such characteristics is the fact that the FRS terne coated steel solders easily so that pretinning or other special preparations are not required. This characteristic assures leakproof seams and joints. Importantly, the FRS terne coated steel is one of the most easily worked metals permitting on-site formation of standing seams without difficulty. The terne coated sheeting which is usually supplied in 26 to 28 gauge thickness (0.015 to 0.018 inches) is strong, takes shape and holds it but is easily worked. This is an important characteristic of the FRS system permitting not only easy installations but precise placement and forming of waterproof seams. Also, the FRS terne coated steel is not effected by alkali attack permitting applications in which contact with cement is possible and the terne coating is anodic to stainless steel which means that the terne coating will sacrifice itself to protect the core metal.
The aforementioned characteristics of the terne coated steel allows for a unique construction of either preformed or job site formed roofing pans, cleats, caps and other components which collectively form and have become widely known in the trade as the FRS system. Reference should be had to Boyd U.S. Pat. Nos. 4,934,120; 4,982,543; 4,987,716; 5,001,881 and 5,022,203 for a detailed discussion of the FRS system and many of the components used therein.
Despite all the advantages and inherent functional characteristics of the terne coat steel which permitted and enabled the development of the FRS system, terne coated steel is unsuitable for use in a potable water collecting system. This deficiency is not limited to terne coated steel but is applicable to all other metals currently used in conventional metal roof systems. For example, roofing systems formed from only stainless steel form standing seams by resistance welding, and the welding causes corrosion which can contaminate rain water and significantly reduce the life span of the roof.
SUMMARY OF THE INVENTION
It is a principal object of the present invention to provide a water collecting system which uses a roof system of an inert or neutral material which is unreactive to water and which is unsuitable for collecting potable water drained between standing seams int he roof.
This object, along with other features of the invention, is achieved by means of a conventional type water gathering system employing a roofing system, method or apparatus (or alternatively a roofing system, method or apparatus adapted for use in a water gathering system), which roofing system uses fully annealed sheets of titanium having at least 99% titanium and a thickness of less than 0.020 inches, generally within 0.010-0.015 inches and specifically between 0.012-0.014 inches. Preferably the sheets are pre-formed into roof pans by forming the first edge of the strip into a first standing seam element with a first integral wall extending orthogonally from the strip and coterminous with the first edge so that the first standing seam element terminates in an outwardly extending flange and the second edge of the strip is formed into a second standing seam element, with the second integral wall extending orthogonally from the strip and coterminous with the second edge so that the second standing seam element terminates in an inwardly extending flange. Preferably the roof pans are formed of titanium sheets cut into lengths which do not exceed about ten feet, with a width extending between sheet edges of no more than about three feet. The roof substrate of the building is covered by placing two of the formed titanium strips or pans in side-by-side relationship, with each of the strips forming water draining troughs in the direction of the pitch of the roof. The first standing seam element of the first of the two pans abuts the second standing seam element of the second pan with abutting seam elements folded into an outwardly protruding standing seam between the two pans so that the integral walls of the abutting seam elements remain somewhat orthogonal to the flat base sections of the first and second tintanium pans. More specifically, the abutting standing seam elements are simply press fitted into a standing seam and preferably the orthogonal walls of the abutting seam elements are press fitted together at a position below the press fitted standing seam whereby a titanium, waterproof standing seam is formed in the welding, soldering or otherwise permanently affixing the seam elements to one another, thus avoiding metal corrosion to assure potable water while forming waterproof seams capable of thermal expansion and contraction in a system having exceptional long life characteristics. Alternatively, a compressible sealant, or still further alternatively, a compressible sealant-adhesive can be applied to one or more of the standing seam elements prior to forming the standing seam.
In accordance with another aspect of the invention, an elongated, attachment cleat formed from a fully annealed titanium sheet of at least 99% titanium and having a lower generally flat plate member and an orthogonal wall member is provided, and the flat plate member of the attachment cleat is fastened to the substrate with the cleat wall member extending upwardly between abutting standing seam elements, whereby the cleat is folded with the abutting standing seam elements into the standing seam which is entirely titanium to avoid any galvanic action or other chemical reactions between roofing components.
In accordance with a specific feature of the invention, titanium strips or pans are formed with a trailing end and a leading end so that the edge of the trailing end between standing seam elements is folded back on top of the strip and the edge of the leading end between standing seam elements is folded back under the strip. Longitudinally adjacent roof pans are abutted so that the leading end of the highest strip or pan overlies the trailing end of the adjacent strip or pan. A titanium fastening cleat having a C-shaped open end is secured to the roof substrate and the trailing end of the lower pan in turn is inserted into the C-shaped opening of the fastening cleat and secured thereto. A titanium clip having an offset edge is affixed by adhesive a predetermined distance from the trailing end of the lower pan and intermediate the roof pan sealing elements. The leading edge of the higher pan is inserted into the offset portion of the offset clip as the trailing edge of the lower pan is inserted into the fastening cleat and the standing seam is continuously formed between adjacent pans whereby a water tight cross seam secured to the roof substrate is formed between adjacent pans which permits thermal expansion and contraction of the pans.
In accordance with yet another specific feature of the invention, a first plurality of the formed titanium pans are placed side-by-side with standing seams formed therebetween to cover a first portion of the roof substrate and a second plurality of the formed titanium strips are placed side-by-side with standing seams formed therebetween to cover a second portion of the roof substrate and the first and second portions are situated relative to one another so that the trailing axial ends of the first plurality of titanium pans are adjacent but spaced from the trailing axial ends of the second plurality of titanium pans. A titanium batten clip of somewhat S-shaped configuration is provided. The batten clip has a web section generally orthogonal to the pan's standing seam elements which transversely extends between standing seam elements and is adjacent to the trailing axial ends of the pans in the first and second pluralities which in turn are adjacent one another. The batten clip includes an attachment leg extending from the web section above the standing seam elements and away from the pan's axial end, and a base section extending from the pan's trailing web section toward the pan' s trailing axial end. The base section is affixed by adhesive to the central or base portion of the roof pan at a predetermined distance from the pan's trailing axial end. A titanium ridge cap of generally V-shaped configuration having ends forming an acute angle with each leg of the V is provided and the ridge cap ends are bent under the attachment leg of the batten clip to affix the ridge cap to the strips by means of the batten clips so that the axial ends of the titanium roof pan of the roof apex are covered in a waterproof manner.
It is thus another object of the present invention to provide a metal roofing system using titanium sheets.
It is another object of the present invention to provide a metal roofing system which is chemically, electrically and mechanically inert or neutral, insofar as the roof system has any effect on or reaction with rain water.
It is still yet another object of the invention to provide a potable water gathering system employing a metal roofing system constructed of titanium having any one or more of the following features:
(a) Titanium sheet characteristics are specified so that the titanium sheet has sufficient rigidity and toughness to function in a manner equivalent to that of a terne coated stainless sheet roofing member while possessing sufficient formability characteristics to permit formation of a standing seam and retention thereof;
(b) On-site formation of a standing seam without welding and optionally without use of sealants and even adhesives while retaining water tight characteristics notwithstanding thermal expansion and contraction of the material; and/or
(c) Minimal use of adhesive, specifically minimal use of adhesive only for clip attachment.
It is yet another object of the invention to provide a roof system in which the color of the metal can be predetermined, within limits, and maintained throughout the metal cross-section and the life of the roof system.
It is another object of the invention to provide a metal roofing system which does not require any plating, coating or paint which otherwise could chip or flake during the life of the roof.
Still yet another object of the invention is to provide a titanium sheet metal roof system which is easy to install and/or inexpensive when compared to that of existing other roof systems and/or long lasting and/or easily repaired and/or relatively maintenance free.
It is still yet another object of the invention to provide a roof system ideally suited for large buildings with low pitch roofs employing standing seam joints formed on site for collecting potable rain water carried from the building by the roof system.
These and other objects of the present invention will become apparent to those skilled in the art upon a reading of the detailed description of the invention set forth below taken together with the drawings which will be described in the next section.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may take physical form in certain parts and arrangement of parts, preferred and alternative embodiments of which will be described in detail and illustrated in the accompanying drawings which form a part hereof and wherein:
FIG. 1 is a pictorial view of a building provided with a metal roof assembly of the present invention;
FIG. 1A is an end view of the building shown in FIG. 1 illustrating in schematic form a water collecting reservoir therefor;
FIG. 2 is a perspective view of a pair of adjacent roofing pans formed from titanium strip used to cover the roof substrate of the building shown in FIG. 1;
FIG. 3 is a perspective, partially cross-sectioned view showing the initial positioning on a roof substrate of two adjacent roofing pans held by an alternative embodiment of an anchoring cleat;
FIG. 3A is a perspective cross-sectioned view similar to FIG. 3 but illustrating a preferred embodiment of the anchoring cleat;
FIG. 4 is a perspective, partially cross-sectioned view of the roofing pans formed into a standing seam taken along line 4--4 of FIG. 1;
FIG. 4A is a perspective, partially cross-sectioned view similar to FIG. 4 but showing a preferred embodiment of the anchoring cleat;
FIG. 5 is a cross-sectional view of the standing seam formed between two adjacent roof pans with a schematic illustration of the force applied to form the standing seam;
FIG. 6 is a cross-section view of the standing seam shown in FIG. 5 with an alternative method step diagrammatically illustrated;
FIG. 7 is a cross-sectional view of titanium strips assembled to one another by a step used in an alternative embodiment of the invention;
FIG. 8 is a sectioned perspective view illustrating a cross seam construction used in the present invention; and,
FIG. 9 is a view taken along lines 9--9 of FIG. 1 illustrating the ridge cap construction used in the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings wherein the showings are for the purpose of illustrating preferred and alternative embodiments of the invention only, and not for the purpose of limiting the same, there is shown in FIG. 1 a building 10 having a low pitch roof 11 covered by strips of titanium sheets formed into roof panels or pans 12 secured to a roof substrate 14 (best shown in FIGS. 3-9). Pans 12 are elongated or longitudinally extend in the direction of the pitch of roof 11 and because of the cross seam construction, as will be described with reference to FIG. 8, the preferred embodiment of the invention is limited to roofs of low pitch which, for purposes of this invention, is defined as being six inches or less to the foot.
Referring now to FIG. 1A, there is illustrated schematically the water collecting system of the present invention. In accordance with the invention adjacent roof pans 12 are joined together to form a standing seam so that the pan section between adjacent standing seams forms a trough 20 in which water flows from high to low portions of the roof along the roof pitch. The water drains into a gutter 16 and from there to a downspout 17 where it collects in an appropriate reservoir 18 and a valved opening 19 is provided for draining reservoir 18. Gutter 16, downspout 17 and reservoir 18 are preferably formed of an inert, nonreactive material such as titanium so that contamination of the potable rain water does not occur.
One of the essential features of the present invention is that the roofing material use in the water collecting roof system described herein be an inert, nonreactive (chemically or otherwise) material which will not contaminate the rain water collected by the system or otherwise render the water unfit for human consumption, but at the same time possess mechanical, chemical and physical properties which are functionally suitable from durability, aesthetics and application considerations for roofing material used in a roofing system. It has been determined after investigation and experimentation that titanium in sheet form having the composition and characteristics set forth below will adequately function in a roofing system and will have attributes similar to the FRS system provided that provisions are made to the roofing system as set forth herein. The titanium sheet, i.e. the preferred embodiment disclosed herein, is specified as follows:
Compositional limits (ASTM B265 Grade 2):--0.03% max N: 0.10% max C: 0.015% max H: 0.18% max 0.020% max Fe: 0.05% max others (each): 0.3% max others (total).
Metallurgical: Composed of alpha phase characterized by a hexagonal close-packed structure which is stable from room temperature to approximately 1620° F. Alpha alloy cannot be heat treated to develop higher mechanical properties since it is a single-phase alloy. The material has an equiaxed grain structure and so is in the annealed condition, and can be cold or hot rolled.
______________________________________MECHANICAL (as measured):Yield strength 47900 Lb/square inchTensile strength 57000 Lb/square inchElongation 22.55% in 2 inchesHardness 81.2 Rockwell B ScaleThickness 0.014 inchesPHYSICAL:Density 0.163 Lbs/cu inMelting point 3020 F.Beta Transus 1675 F.Specific Heat 0.124 Btu/Lb/F.Thermal conductivity 9.5 Btu/hr./Sq. Ft/F./FtCoeff. of expansion 0.000009/CElectrical resistivity 56 Microhm.cmPoisson's Ratio 0.34THICKNESS: Less than 0.020 inches 0.010-0.015 inches, generally 0.012-0.014 inches, specifically______________________________________
Flat titanium sheet meeting the specifications defined above is commercially available. Depending on the annealing treatment, it is possible to obtain the titanium in different colors. One source of such titanium sheet is Sumitomo Metal Industries, Ltd.
Titanium sheet furnished to this specification has excellent strength and durability characteristics which make it suitable for use in the metal roofing system. At the same time even though the material possesses a high yield strength, it can be formed at the job site into the system as described hereafter. The assembly is characterized by the absence of any welding of the titanium strip. It is known that titanium has a strong affinity for oxygen, nitrogen and hydrogen gases. When welded under high temperature conditions titanium will absorb oxygen and nitrogen gases and become hard and brittle. Conventional practice require that welding of titanium be done in an environment where the strip can be shielded by inert gases to prevent oxidation of titanium which will adversely affect the life expectancy of the roof and contribute to premature failures as the roof system expands and contracts. In addition, it is also to be noted that the titanium strip of the present invention whether supplied as hot rolled or cold rolled is furnished in a fully annealed condition so that it can be formed into the shapes hereafter defined.
Titanium strips in widths not exceeding about thirty inches are preferably cut into lengths not exceeding about ten feet and preformed into roof pans 12 having a shape shown in FIG. 2. More specifically, the strip has a width extending between longitudinally extending first and second edges 23, 24. The strip is formed adjacent its first edge 23 into a first standing seam element or right hand end 25 which extends orthogonally from the flat strip pan base section 27 and terminates in outwardly extending flange while the strip adjacent the second strip edge 24 is formed into a second standing seam element or left hand end 29 which extends orthogonally to pan base section 27 and terminates in an inwardly extending flange. More specifically, right hand end 25 formed as an outwardly extending flange has an upstanding leg portion 31 terminating in a bight wall portion 32 generally parallel to pan base 27 which in turn terminates in a downwardly extending end wall portion 33 to define a flange which may be viewed as channel-shaped in cross-sectional configuration. Left hand edge 29 of roof pan 12, formed as an inwardly extending flange, is defined by an upwardly extending leg portion 35 orthogonal to pan base 27 which terminates in an end wall portion 36 which is generally parallel to pan base 27. The transversely extending axial ends of roof pans 12 are for definitional purposes defined as a leading end 38 and a trailing end 39. It is to be understood that designations of right hand, left hand, leading, trailing, upwardly and downwardly are all relative terms and are simply used to define orientation of the components used in the system of the invention and are not used in the specifications or int he claims in the sense of what the terms mean in their absolute definitional sense. As thus defined, roofing pans 12 are similar in configuration but dimensionally different from that used in the FRS system.
Basically, the roof of building 10 is covered by positioning adjacent roof pans, 12a, 12b (FIG. 2) so that their longitudinally extending edges 23, 24 are aligned to extend along the pitch (shown by dash line indicated by reference numeral 41 in FIG. 3) of the building's roof. One of the pans 12a is then rotated so that its left hand edge 29 will slide underneath end wall 33 of adjacent pan 12b and the two pans 12a, 12b can be thus abutted so that the left hand upstanding wall 35 is adjacent right hand upstanding wall 31 and end wall 36 is underneath bight wall 32. A waterproof standing seam 40, as hereinafter described, is then formed between right hand and left hand ends, 25, 29 of adjacent roof pans 12a, 12b. In order to secure roof pans 12 to roof substrate 14 an attachment cleat 45 is provided.
Referring now to FIGS. 3, 3A and 4, 4A, it should be noted that attachment cleat 45 shown in FIGS. 3 and 4 represent an alternative form of attachment cleat while attachment cleat 47 shown in FIGS. 3A and 4A represents the preferred embodiment of the attachment cleat used in the invention. Also, in accordance with conventional practice prior to installing the roof, an underlayment consisting of a layer of felt (15 lbs. minimum) covered with a slip sheet of rosin paper, not shown in the drawings, is positioned on top of roof substrate 14. Attachment cleat 45 which in the alternative embodiment shown in FIGS. 3 and 4 is shown as a continuous cleat has a flat base section 49 secured by fasteners 50 parallel to or co-axial with roof pitch line 41. Attachment cleat base section 49 terminates in a web section 52 which extends orthogonally to base section 49 and terminates in an end section 53 which is parallel to base section 49 to define a channel-shaped cross-section configuration attachment cleat. With attachment cleat 45 affixed to roof substrate 14 by fasteners 50 one of the roof pans, i.e. 12b, is brought into abutting relationship with attachment cleat 45 so that its right hand end 25 overlies attachment cleat 45. That is, upstanding leg portion 31 abuts web section 52 and bight wall portion 32 overlies end section 53. An adjacent pan 12a is then rotated into position as described above so that its left hand end 29 underlies attachment cleat 45. That is, upstanding leg portion 35 abuts web section 52 and end wall portion 36 underlies end section 53 to produce the relationship illustrated in FIG. 3 prior to forming standing seam 40. In the embodiment shown in FIGS. 3 and 4, base pan section 27 is shown formed with longitudinally extending strengthening grooves 55 formed therein although this is not necessary when roof pans 12 are formed of titanium sheet. Upstanding seam 40 is then formed as shown in FIG. 4 by first folding end wall portion 33 against the underside of end wall portion 36 and then bending the standing seam elements so that bight wall portion 32 and left hand end wall portion 36 and attachment cleat end section 53 is generally parallel to pan upstanding wall portions 31, 35 and attachment cleat web section 52. When standing seam 40 is formed pan base section 27 becomes stretched or tensioned with the result that left hand upstanding wall portion 35 is pulled away from cleat web section 52 and upstanding wall portion 31 is likewise pulled away from cleat web section 52 as best shown in FIG. 4. Typically, the total height of upstanding leg portions 31, 35 and web section 52 is about one inch and about one-third of this distance as indicated by dimension "x" in FIG. 4 is taken up by the formed standing seam 40 so that about two-thirds of the distance is taken up by standing leg portions 31, 35 which are stretched as a result of forming standing seam 40. Attachment cleats 45, 47 as are all other attachments described herein are formed from titanium sheets to avoid any galvanic action or chemical reaction which would occur if the cleats were made of a dissimilar material. In addition, attachment cleats 45, 47 are made from about the same gauge or thickness as that of roof pans 12.
Referring now to FIGS. 3A and 4A, the preferred form of attachment cleat 47 is shown. Attachment cleat 47 as contrasted to attachment cleat 45 has a discrete length of about two inches and a plurality of attachment cleats 47 are positioned at ten to twelve inch spacing along pitch line 41. Attachment cleat 47 has a flat base section 57 with openings for receiving a pair of fasteners 58, the heads of which are covered by a fold over flap portion 59 of base section 57. Attachment cleats 47 can be provided with fasteners 58 retained in place by fold over flap section 59 retaining fasteners 58 or flap section 59 can be folded over after attachment cleat 47 is affixed to substrate 14 on the job site. A web section 60 extends upwardly and orthogonally to base section 57 and terminates in an end section 62 which, like attachment cleat 45, is parallel to base section 57. However, end section 62 of attachment cleat 47 terminates in an end flap section 63 angularly extending vertically downwardly as best shown in FIG. 3A. End flap section 63 better assures positioning or a "snapping in" of left hand end 29 of roof pan 12 than does attachment cleat 45 and in addition better assists in forming standing seam 40. That is attachment cleat produces an eight wall thickness standing seam which enhances the water tightness of the standing seam joint when formed in a press fit manner. Attachment cleats 45, 47 are similar to attachment cleats used in the FRS system although dimensionally different.
Referring now to FIG. 5, there is diagrammatically illustrated plunger ends 67, 68 of a hydraulic machine described and discussed in detail in Boyd U.S. Pat. No. 4,987,716 which is incorporated by reference herein so that the details of the various embodiments of that machine need not be described further in this specification. It is sufficient for an understanding of the present invention to note that standing seam 40 is formed by plungers 67, 68 exerting very high compressive force, in excess of two to three thousand psi so that a press fit is established between all of the wall sections of standing seam 40. In the present invention the press fit in and of itself provides the waterproof seam which retains its waterproof characteristics notwithstanding thermal expansion and contraction of roof pans 12. It should be noted that in the FRS system which utilized a press fit the terne coating on the stainless sheet functions in part as a solid sealant and to some extent the low melting point of the lead in the terne acts as an adhesive. Thus, the press fit in the FRS system distorted the terne coating which acted as a sealant and, even to some extent, a solder so that the standing seam was sealed. In the present invention, the physical and mechanical properties of the titanium sheet are different than the stainless steel sheet. The titanium sheet, although thinner than the stainless steel sheet used in the FRS system, requires a higher compressive force than the stainless steel sheet used in the FRS system to form the standing seam. However, because the titanium sheet is fully annealed, it can be formed into the standing seam, and when formed into a press fit standing seam, the press fit force coupled with the properties of the titanium sheet permits the seam to retain its water tight seam despite thermal contraction and expansion and cold climate application which produces ice. As is well known formation of ice in thawing and freezing temperatures will produce leaks in conventionally formed standing seams which heretofore required the seams to be soldered. The press fit standing seam of the present invention obviates the need for welding or soldering the seam either of which cannot be effected with titanium sheets for reasons discussed above. Nevertheless, in accordance with the broad concepts of the invention, a sealant such as butyl rubber caulk can be applied to one of the roof pans 25, 29 and a sealant which has adhesive characteristics such as one of the conventional vinyl caulks used for roof flashing can also be used. It is also possible to use conventional adhesive such as that used by airframe manufacturers to glue titanium sheets and physically bond the standing seam elements to one another.
FIG. 6 illustrates a further alternative embodiment to be used in conjunction with the press fit standing seam illustrated in FIG. 5. In FIG. 6, hydraulic plungers 69, 70 press fit upstanding leg portion 31 of right hand pan end 25 with upstanding leg portion 35 of left hand pan end 29 together with or without web section 52 of attachment cleat 45 sandwiched therebetween. This press fit occurs in the "y" distance and relieves tension exerted by pan base section 27 on standing seam 40. Preferably, one of the plungers 70 has a protrusion formed at its base (not shown) with a recess (not shown) formed in the opposite plunger 69 so that the leg portions 31, 35 are actually crimped into one another providing a second waterproof seam. The alternative embodiment thus shown in FIG. 6 contemplates the use of two press fit seams to obviate the need of any sealant or adhesive for the establishment of a waterproof joint between adjacent roof pans, 12a, 12b.
Referring now to FIG. 8, there is illustrated the details of a cross seam arrangement to be used in the roofing system of the invention. As noted above, roof pans 12 are preferably limited in length to ten feet or less. Thermal expansion or contraction of roof pan 12 in a transverse direction is compensated by varying the attitude of right hand upstanding leg portion 31 and left hand upstanding leg portion 35 so long as the width of the sheet is maintained within the limit specified. Thermal expansion and contraction in a longitudinal direction, while maintaining the integrity of press fit standing seam 40, is compensated for by limiting the length of roof pans 12 to about ten feet, preferably eight feet, and utilizing the cross seam arrangement shown in FIG. 8. Roof pans 12 are axially connected with leading end 38 adjacent and overlying the trailing end 39 to permit the longitudinal expansion and contraction of standing seam 40 without adversely affecting its press fit, water sealing characteristics. Longer length pans undergo thermal expansion and contraction in the longitudinal and transverse direction which have, cumulatively, an adverse effect on standing seam 40.
Leading end 48 of roof pan 12 is formed with a fold under flap section 72 which, as its name indicates, is folded under pan base section 27 to form a C-shaped end. Fold under section 72 transversely extends over a portion of leading end 38 between or intermediate right hand and left hand pan ends 25, 29. Similarly, trailing end 39 has a fold over flap section 74 which is folded over on top of pan base section 27 and likewise transversely extends between or is intermediate right and left hand ends 25, 29. Roof pans 12 are positioned end-to-end so that leading end 38 of a higher pan 12c overlies trailing end 39 of the lower roof pan 12d, and multiple upstanding leg portions of right hand and left hand ends 25, 29 are abutting one another to form a "thick" standing seam at the axial ends of the pans. A titanium cross seam cleat 76 is used to secure trailing end 39 to roof substrate 14. Cross seam cleat 76 has a flat base section 77 with openings through which fasteners 79 can be applied to secure cross seam cleat 76 to substrate 14. As in attachment cleat 47, cross seam cleat has a fold over covering section 80 which sandwich the heads of fastener 79 therebetween. Extending from flat base section 77 of cross seam cleat 76 is an offset section 82 which in turn terminates in a fold under flap section 83 defining a U-shaped or C-shaped end opening. Pan fold over flap section 74 of trailing end 39 fits within fold under flap portion 83 of cross seam cleat 76 so that the C-shaped pan trailing end 39 is interlocked into the U-shaped flap section 83 of cross seam cleat 76. A fastening clip 85 is used to secure leading end 38 of higher roof pan 12c to trailing end 39 of the underlying roof pan 12d. Fastening clip 85 simply comprises a strip of titanium having a flat base end 86 and an attachment end 88 vertically offset from flat base end 86. Fastening clip 85 is bonded to pan base section 27 adjacent pan trailing end 39 at a fixed distance therefrom by means of an adhesive 89 conventionally used in manufacturing air frames formed of titanium sheet. With the lower roofing pan 12d secured to cross seam cleat 76 in the manner described, the overlying roof pan 12c is fitted into position by having its fold under flap 72 engage the underside of attachment end 88 of fastening clip 85. Over the distance that upper pan 12c overlies lower pan 12d, upwardly extending leg portions 31, 35 of upper pan 12c are outboard of but abutting upwardly extending leg portions 31, 35 of lower pan 12d.
Fastening clips 85 are adhesively secured to roof pan base section 27 in the field after the pans have been arranged in the position shown in FIG. 8, or alternatively, roof pans 12 can be provided with fastening clips 85 premounted. An alternative embodiment is generally illustrated in FIG. 7 and describes a construction in which leading end 38 of roof pan 12 is are not folded over but simply rests on top of trailing end 39 of adjacent roof pan 12 and is secured to trailing end 39 by means of adhesive 89. This is simply illustrated as an alternative form of construction. The cross seam construction illustrated in FIG. 8 is preferred because it permits relative movement of roofing pans. However, it should simply be noted that the detail shown in FIG. 7 may be utilized in the installation of titanium flashing if required for the roof system.
Referring now to FIG. 9, there is shown a construction detail for installation of a roof cap 90 installed, for example, at the apex of the building roof shown in FIG. 1. Roof cap 90 is formed of titanium sheet and is in the form of a V-shape with legs 92, 93 of the "V" terminating at ends 95, 96 respectively. In its preformed "as supplied" shape, ends 95, 96 of roof cap 90 form an acute angle with legs 92, 93 and ends 95, 96 are folded over at the job site into the assembled position shown in FIG. 9. The trailing ends 39 of the highest most roofing pans 12e are formed into an L-shaped cross-section configuration 98 as shown in FIG. 9 and this box end construction 98 extends between right and left hand pan ends 25, 29 to prevent water from entering building 10 through the roof apex. A batten clip 100 is provided for attaching roof cap 90 to roof pans 12e. Batten clip 100 has a somewhat S-shaped cross-section configuration extending between right and left hand ends 25, 29 of each roof pan 12e . Batten clip 100 includes a central web section 101 vertically extending higher than standing seam 40. Extending from the bottom of web section 101 adjacent box end 98 is a flat base section 103 secured by adhesive 89 to pan base section 27. Extending from the top of web section 101 away from box end 98 and parallel to flat base section 103 is attachment section 104. Roof cap ends 95, 96 are folded under attachment section 104 to secure roof cap 90 to adjacent pans 12e at the roof apex, thus preventing water from entering the building through the roof apex.
The invention has been described with reference to preferred and alternative embodiments. Modifications and alterations will become apparent to those skilled in the art upon a reading and understanding of the detailed discussion of the invention provided for herein. It is intended to include all such modifications and alterations insofar as they come within the scope of the present invention.
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A method and system for applying a water gathering and channeling roof covering onto the upper roof of a building, which roof is at least slightly pitched, wherein fully annealed sheets of at least 99% titanium with a thickness of less than 0.020 inches are preformed into roof pans with right hand and left hand edges thereof formed into matching, longitudinally extending standing seam elements. The pans are placed in adjacent, abutting relatinship with one another and joined together by press fitting adjacent standing seam elements into a standing seam extending along the roof's pitch and forming a water collecting trough for gathering potable rain water.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of Korean Patent Application No. 2007-49266, filed on May 21, 2007 and No. 2007-86874, filed on Aug. 29, 2007 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
BACKGROUND
1. Field
The present invention relates to a washing machine and a control method thereof, and, more particularly, to a washing machine that is capable of maintaining the balanced state of laundry to more smoothly perform a spin-drying operation and a control method thereof.
2. Description of the Related Art
Generally, a washing machine (normally, a drum-type washing machine) is a machine, including a water tub to receive water (wash water or rinse water), a cylindrical drum rotatably mounted in the water tub to receive laundry, and a motor to generate a drive force necessary to rotate the drum, that washes the laundry by lifting and dropping the laundry in the drum along the inner wall of the drum during the rotation of the drum.
The washing machine performs laundry cleaning through a washing operation of removing contaminants from laundry with water containing detergent dissolved therein (specifically, wash water), a rinsing operation of removing bubbles or remaining detergent from the laundry with water containing no detergent (specifically, rinse water), and a spin-drying operation of spin-drying the laundry at a high speed. For the spin-drying operation, as shown in FIG. 1 , when a drum 10 is rotated at a high speed while laundry 12 is nonuniformly distributed along the inner wall of the drum 10 , i.e., the laundry 12 is unbalanced, an eccentric force is applied to a rotary shaft of the drum 10 , with the result that large vibration occurs.
In order to prevent the occurrence of the vibration due to the unbalanced state of the laundry, it is necessary to perform a process to uniformly distribute the laundry 12 in the drum 10 , as shown in FIG. 2 , before the spin-drying operation. This is because, when the spin-drying operation is performed in the unbalanced state of the laundry, the spin-drying time may be increased, and spin-drying errors may occur. In addition, when the laundry 12 is removed from the washing machine after the completion of the laundry cleaning, a large amount of force is required because the laundry is tangled, which causes dissatisfaction of main users.
In order to solve this problem, an unbalance reduction control procedure is performed to maintain the balanced state of the laundry 12 in the conventional art. As shown in FIG. 3 , the unbalance reduction control procedure includes a laundry untangling process {circle around ( 1 )} to untangle the tangled laundry 12 by rotating the drum 10 in alternating directions when a spin-drying operation is initiated, a laundry wrapping process {circle around ( 2 )}- 1 to attach the laundry 12 to an inner wall of the drum 10 by rotating the drum 10 at predetermined speeds rpm 1 and rpm 2 , a laundry amount detecting process {circle around ( 3 )} to estimate a weight of the laundry 12 , an unbalance detecting process {circle around ( 4 )} to estimate an unbalance size in the drum 10 using the estimated weight information and a control variable, such as a speed ripple or a current ripple, and a high-speed spin-drying process {circle around ( 5 )} to discharge moisture contained in the laundry 12 outside using a centrifugal force caused by rotating the drum 10 at a high speed when the estimated unbalance size is within an allowable value. These processes are sequentially performed. When the estimated unbalance size is greater than the allowable value, on the other hand, the procedure returns to the laundry untangling process {circle around ( 1 )} and then the unbalance reduction control procedure is repeated.
In the laundry wrapping process {circle around ( 2 )}- 1 , the rotation speed is accelerated from the first rotation speed rpm 1 to the second rotation speed rpm 2 , which is greater than a speed at which the laundry 12 sticks to the inner wall of the drum 10 , and the state of the laundry 12 is not considered during the increase of the rotation speed of the drum 10 to the rpm 2 . For a load such as a small amount of laundry 12 or blue jeans, the balance of which is difficult to maintain, the unbalance is great, even after the laundry wrapping process {circle around ( 2 )} is completed. As a result, it is not possible to rotate the drum 10 at a high speed, and the laundry untangling process {circle around ( 1 )} may be reperformed. On the assumption that a probability of maintaining the balance through the laundry wrapping process {circle around ( 2 )}- 1 is 10%, and time required to perform the procedure from the laundry untangling process {circle around ( 1 )} to the unbalance detecting process {circle around ( 4 )} is 1 minute, for example, the balance is maintained after the unbalance reduction control procedure is performed 10 times on average, and therefore, it takes approximately 10 minutes until the high-speed spin-drying process is initiated. This spin-drying time is excessive.
SUMMARY
Therefore, it is an aspect of the embodiments to provide a washing machine that is capable of reducing unbalance reduction control time to maintain the balanced state of laundry through an improved laundry wrapping process, thereby reducing a total spin-drying time, and a control method thereof.
It is another aspect of the invention to provide a washing machine that is capable of determining the unbalanced state of laundry in real time during a laundry wrapping process, and, when the laundry is unbalanced, reperforming only the laundry wrapping process to greatly improve a laundry wrapping success rate, thereby greatly reducing a total unbalance reduction control time, and a control method thereof.
Additional aspects and/or advantages will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the invention.
The foregoing and/or other aspects are achieved by providing a control method of a washing machine including a drum to receive laundry and a motor to rotate the drum to reduce unbalance generated due to the nonuniform distribution of the laundry, including wrapping the laundry by accelerating the drum such that the laundry sticks to an inner wall of the drum, detecting motor current during the wrapping of the laundry, determining whether the laundry is in an unbalanced state or a balanced state based on the detected motor current, and controlling speed of the drum based on the result of the determination.
The wrapping the laundry may include accelerating the speed of the drum by stages to reduce the unbalance of the laundry before a high-speed spin-drying operation.
The accelerating the drum may include accelerating the speed of the drum by stages, and controlling the speed of the drum accelerated by stages based on the detected motor current.
The speed of the drum may include a first rotation speed at which the laundry does not stick to the inner wall of the drum, a second rotation speed at which the laundry sticks to the inner wall of the drum, the second rotation speed being higher than the first rotation speed, and a third rotation speed at which the laundry starts to stick to the inner wall of the drum, the third rotation speed being between the first rotation speed and the second rotation speed.
The detecting motor current may include detecting a magnitude of the motor current when the speed of the drum exceeds the third rotation speed at an operation at which the speed of the drum is accelerated from the first rotation speed to the second rotation speed.
The controlling the speed of the drum may include reperforming the laundry wrapping operation by accelerating the speed of the drum from the first rotation speed, when it is determined that the laundry is in the unbalanced state.
The controlling the speed of the drum may include performing a high-speed spin-drying operation by continuously accelerating the speed of the drum, when it is determined that the laundry is in the balanced state.
The determining whether the laundry is in the unbalanced state or the balanced state may include searching for a minimum value of the detected motor current to compare the minimum value of the motor current to a predetermined current limit value, and determining that the laundry is in the unbalanced state, when the minimum value of the motor current is less than the predetermined current limit value.
The minimum value of the motor current may be a minimum current value at an operation at which the speed of the drum is accelerated from the third rotation speed to the second rotation speed.
The foregoing and/or other aspects are achieved by providing a control method of a washing machine including a drum to receive laundry and a motor to rotate the drum to reduce unbalance generated due to the nonuniform distribution of the laundry, including wrapping the laundry by accelerating the drum such that the laundry sticks to an inner wall of the drum, determining an unbalanced state of the laundry using duty information applied to the motor during the wrapping of the laundry, and controlling speed of the drum based on a result of the determination.
The determining the unbalanced state of the laundry may include calculating a size of a reference duty during the acceleration of the drum to determine the difference between an actual duty applied to the motor and the reference duty, generating an unbalance determination signal from a minimum value of the difference between the actual duty and the reference duty to compare the unbalance determination signal to a predetermined unbalance limit value, and determining that the laundry is in the unbalanced state when the minimum value of the difference between the actual duty and the reference duty is less than the unbalance limit value.
The foregoing and/or other aspects are achieved by providing a washing machine including a drum to receive laundry, a motor rotating the drum, and a control unit controlling speed of the drum based on a result of a determination as to whether the laundry is in an unbalanced state or a balanced state, by detecting motor current during an acceleration of the drum.
The control unit may perform a laundry wrapping operation to reduce an unbalance of the laundry, by accelerating the speed of the drum by stages, before a high-speed spin-drying operation.
The control unit may control the speed of the drum accelerated by stages based on the detected motor current.
The control unit may store a first rotation speed at which the laundry does not stick to an inner wall of the drum, a second rotation speed at which the laundry sticks to the inner wall of the drum, the second rotation speed being higher than the first rotation speed, and a third rotation speed at which the laundry starts to stick to the inner wall of the drum, the third rotation speed being between the first rotation speed and the second rotation speed.
The control unit may detect a magnitude of the motor current when the speed of the drum exceeds the third rotation speed at an operation at which the speed of the drum is accelerated from the first rotation speed to the second rotation speed.
The control unit may search for a minimum value of the detected motor current to compare the minimum value of the motor current to a predetermined current limit value, and determines that the laundry is in the unbalanced state when the minimum value of the motor current is less than the predetermined current limit value.
The control unit may reperform the laundry wrapping operation by accelerating the speed of the drum from the first rotation speed, when it is determined that the laundry is in the unbalanced state.
The control unit may perform a high-speed spin-drying operation by continuously accelerating the speed of the drum, which is being accelerated to the second rotation speed, when it is determined that the laundry is in the balanced state.
The foregoing and/or other aspects are achieved by providing a washing machine including a drum to receive laundry, a motor rotating the drum, and a control unit controlling speed of the drum based on a result of a determination as to an unbalanced state of the laundry using duty information applied to the motor during an acceleration of the drum.
The foregoing and/or other aspects are achieved by providing a control method for a washing machine including a drum to receive laundry and a motor rotating the drum, including: accelerating the drum such that the laundry sticks to an inner wall of the drum to wrap the laundry; determining whether the laundry is in an unbalanced or a balanced state during the wrapping of the laundry; and reperforming the wrapping of the laundry when the laundry is in the unbalanced state.
The determining whether the laundry is in the unbalanced or the balanced state during the wrapping of the laundry may include detecting a magnitude of motor current flowing at a moment at which a rotation speed of the drum exceeds a rotation speed at which the laundry starts to stick to the inner wall of the drum and comparing the detected magnitude of motor current with an unbalance current limit value to determine whether the laundry is in the unbalanced or the balanced state.
BRIEF DESCRIPTION OF THE DRAWINGS
These and/or other aspects and advantages will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, of which:
FIG. 1 is a view illustrating the unbalanced state of laundry in a drum of a washing machine;
FIG. 2 is a view illustrating the balanced state of laundry in a drum of a washing machine;
FIG. 3 is a drum speed graph illustrating an unbalance reduction control procedure of a conventional washing machine;
FIG. 4 is a control block diagram of a washing machine according to embodiments;
FIG. 5 is a drum speed graph illustrating an unbalance reduction control procedure of the washing machine according to the present embodiments;
FIG. 6 is a flow chart illustrating an unbalance reduction control operation of a washing machine according to a first embodiment;
FIG. 7 is a flow chart illustrating an unbalance reduction control operation of a washing machine according to a second embodiment;
FIG. 8 is a view illustrating only a uniform load existing in a drum;
FIG. 9 is a view illustrating motor current and duty traces during a laundry wrapping operation in the uniform load condition of FIG. 8 ;
FIG. 10 is a view illustrating an unbalance existing in a drum together with a uniform load;
FIG. 11 is a view illustrating a duty waveform during a laundry wrapping operation with the load and unbalance of FIG. 10 ;
FIG. 12 is a view illustrating a drum of a washing machine before laundry is wound in the drum;
FIG. 13 is a view illustrating a speed-current waveform when the balance is maintained by the laundry wrapping process of FIG. 6 ;
FIG. 14 is a view illustrating a speed-current waveform when the balance is not maintained by the laundry wrapping process of FIG. 6 ;
FIG. 15 is a view illustrating a duty waveform when the balance is maintained by the laundry wrapping process of FIG. 7 ;
FIG. 16 is a view illustrating a duty waveform when the balance is not maintained by the laundry wrapping process of FIG. 7 ;
FIG. 17 is a view illustrating the trace of an unbalance determination signal when the load and the unbalance are changed; and
FIG. 18 is a view illustrating an application example of a laundry wrapping process of a washing machine according to the second embodiment.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Reference will now be made in detail to the embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The embodiments are described below to explain the present invention by referring to the figures.
FIG. 4 is a control block diagram of a washing machine according to embodiments.
Referring to FIG. 4 , the washing machine includes an input unit 20 to allow a user to input an operation command, including setting of a spin-drying operation, a control unit 22 to control the overall operation of the washing machine, such as washing, rinsing, and spin-drying, a motor driving unit 24 to drive a motor 26 that rotates a drum 10 according to the control of the control unit 22 , a speed detecting unit 28 to transmit a motor speed signal corresponding to the rotation speed of the drum 10 to the control unit 22 , a current detecting unit 30 to transmit a motor current signal corresponding to the rotation speed of the drum 10 to the control unit 22 , and a back electromotive force detecting unit 32 to transmit a back electromotive force proportional to the rotation speed of the drum 10 to the control unit 22 .
The control unit 22 performs an unbalance reduction control procedure to maintain the balanced state of laundry 12 , when a spin-drying operation is initiated, as in the conventional art. As shown in FIG. 5 , the unbalance reduction control procedure according to the present invention includes a laundry untangling process {circle around ( 1 )} to untangle the tangled laundry 12 by rotating the drum 10 in alternating directions when a spin-drying operation is initiated, an active laundry wrapping process {circle around ( 2 )} to determine the unbalanced state of the laundry in real time through the detection of current at the section where the speed of the drum 10 is accelerated from a first rotation speed rpm 1 to a second rotation speed rpm 2 , a laundry amount detecting process {circle around ( 3 )} to estimate the weight of the laundry 12 such that the weight of the laundry 12 is utilized as basic information to estimate an unbalance size using parameters, such as speed change and current ripple of the drum 10 , or set an allowable unbalance size before a high-speed spin-drying operation, an unbalance detecting process {circle around ( 4 )} to estimate an unbalance size in the drum 10 using the estimated weight information and the control variable, such as the speed ripple or the current ripple, and a high-speed spin-drying process {circle around ( 5 )} to discharge moisture contained in the laundry 12 outside using a centrifugal force caused by rotating the drum 10 at a high speed when the estimated unbalance size is within an allowable value. These processes are sequentially performed. When the estimated unbalance size is greater than the allowable value, on the other hand, the procedure returns to the laundry untangling process {circle around ( 1 )}, as in the conventional art, and then the unbalance reduction control procedure is repeated.
The unbalance reduction control procedure according to the present embodiments is characterized by determining the unbalanced state of the laundry in real time, during the laundry wrapping process to reperform only the laundry wrapping process {circle around ( 2 )}.
To this end, the control unit 22 sets a third rotation speed rpm 3 , which is a critical speed at which the laundry 12 starts to stick to the inner wall of the drum 10 during a laundry wrapping operation in which the speed of the drum 10 is accelerated from the first rotation speed rpm 1 to the second rotation speed rpm 2 , and detects the magnitude of motor current (considerably small as compared to the current at the rpm 1 operation section), flowing the moment the rotation speed of the drum 10 exceeds the third rotation speed rpm 3 , through the current detecting unit 30 . When the laundry 12 is unbalanced, the current ripple increases, and the average value of the current decreases, with the result that the minimum value of the current is always approximately 0. Consequently, an unbalance current limit value is set to an arbitrary value of approximately 0, and, when the detected motor current value is less than the current limit value, it is determined that the laundry 12 is in an unbalanced state. When it is determined that the laundry 12 is distributed in the drum 10 in the unbalanced state, the drum 10 is rotated at the first rotation speed rpm 1 to reperform the laundry wrapping process {circle around ( 2 )}.
Also, the unbalance reduction control procedure according to the present embodiment is characterized by determining the unbalanced state of the laundry in real time using duty information (a value proportional to a voltage command applied to the motor), during the laundry wrapping process, to reperform only the laundry wrapping process {circle around ( 2 )}. Here, the duty means a ratio of a switch turn-on section to a switching cycle of a switch to control voltage applied to the motor 26 .
To this end, the control unit 22 sets a third rotation speed rpm 3 , which is a critical speed at which the laundry 12 starts to stick to the inner wall of the drum 10 during a laundry wrapping operation in which the speed of the drum 10 is accelerated from the first rotation speed rpm 1 to the second rotation speed rpm 2 , and calculates the size of a reference duty the moment the rotation speed of the drum 10 exceeds the third rotation speed rpm 3 to generate an unbalance determination signal from the minimum value of the difference between the actually-applied duty and the reference duty, and compares the generated unbalance determination signal with the unbalance limit value. When it is determined that the laundry 12 is distributed in the drum 10 in the unbalanced state, the drum 10 is rotated at the first rotation speed rpm 1 to reperform the laundry wrapping process {circle around ( 2 )}.
The third rotation speed rpm 3 is an arbitrary speed between the first rotation speed rpm 1 and the second rotation speed rpm 2 . The third rotation speed rpm 3 may be changed depending upon the diameter of the drum 10 and the amount and kind of the laundry 12 .
When the laundry 12 is unbalanced, the laundry 12 is changed from the unbalanced state to the balanced state by the re-performance of laundry wrapping process {circle around ( 2 )}. Consequently, the unbalance value estimated at the subsequent unbalance detecting process 4 , falls within the allowable value, and therefore, the unbalance reduction control time that is necessary for the procedure to return to the laundry untangling process {circle around ( 1 )}, is reduced.
Hereinafter, the operation and effects of the washing machine with the above-stated construction and a control method thereof will be described.
FIG. 6 is a flow chart illustrating an unbalance reduction control operation of a washing machine according to a first embodiment. In this embodiment, the unbalanced state of laundry 12 is determined in real time through the detection of current when a spin-drying operation is initiated in order to reduce an unbalance reduction control time to maintain the balanced state of the laundry 12 .
FIG. 7 is a flow chart illustrating an unbalance reduction control operation of a washing machine according to a second embodiment. In this embodiment, the washing machine does not include a current detection circuit, and the unbalanced state of laundry 12 is determined in real time using duty information (a voltage command value) when a spin-drying operation is initiated in order to reduce an unbalance reduction control time to maintain the balanced state of the laundry 12 .
The following description will be given with simultaneous reference to FIGS. 6 and 7 to avoid the duplicate explanation of the same part.
When a user puts laundry 12 in the drum 10 and inputs an operation command including setting a spin-drying operation through the input unit 20 , the control unit 22 sequentially performs a washing operation, a rinsing operation, and a spin-drying operation.
The control unit 22 determines whether the spin-drying operation is initiated ( 100 ) ( 200 ). When it is determined that the spin-drying operation is initiated, the control unit 22 controls the operation of the motor 26 through the motor driving unit 24 to rotate the drum 10 in alternating directions such that a laundry untangling process {circle around ( 1 )} to untangle the tangled laundry 12 is performed as shown in FIG. 5 ( 102 ) ( 202 ). If the control unit determines that the spin-drying operation is not initiated, the procedure returns to operation 100 , 200 .
After the laundry untangling process {circle around ( 1 )}, the control unit 22 performs a laundry wrapping process {circle around ( 2 )} in which the speed of the drum 10 is accelerated from a first rotation speed rpm 1 to a second rotation speed rpm 2 as shown in FIG. 5 ( 104 ) ( 204 ). The first rotation speed rpm 1 is a speed of the drum 10 at which the laundry 12 does not stick to the inner wall of the drum 10 , and the second rotation speed rpm 2 is a speed of the drum 10 at which the laundry 12 sticks to the inner wall of the drum 10 . Between the first rotation speed rpm 1 and the second rotation speed rpm 2 is set a third rotation speed rpm 3 , which is a critical speed at which the laundry 12 starts to stick to the inner wall of the drum 10 .
When laundry wrapping process {circle around ( 2 )} is initiated, the control unit 22 calculates a duty change range (voltage applied to the motor) proportional to the magnitude of a current ripple, while changing the acceleration (rpm/sec) from the first rotation speed rpm 1 to the second rotation speed rpm 2 depending upon the diameter of the drum 10 and the amount and kind of the laundry 12 to generate an unbalance determination signal as follows.
Generally, the equation of motion of a rotary body (specifically, a drum) is as follows.
Te=TL+B·w+J ·( dw/dt ) [Equation 1],
where, T e is electric torque, T L is load torque, B is the coefficient of friction, w is rotational angular velocity, J is the coefficient of inertia, and t is time.
FIG. 8 is a view illustrating only a uniform load existing in the drum. A rubber load 14 , as the uniform load, is mounted to the inner wall of the drum 10 .
FIG. 9 is a view illustrating motor current and duty traces during a laundry wrapping operation in the uniform load condition of FIG. 8 .
Referring to FIGS. 8 and 9 , when the speed of the drum 10 is the first rotation speed rpm 1 or the second rotation speed rpm 2 , there is neither acceleration nor load torque T L , and therefore, only the current component of the torque term B w by the coefficient of friction B exists. At the section where the speed of the drum 10 is accelerated from a first rotation speed rpm 1 to a second rotation speed rpm 2 , the acceleration exists, and therefore, current increased by the magnitude proportional to the product J·(dw/dt) of the inertia J of the load and the acceleration dw/dt flows. Consequently, when the load increases in the same condition, larger current flows during the acceleration. A back electromotive force (emf) is a voltage generated at an input terminal of the motor 26 during the rotation of the motor 26 . Generally, the back electromotive force (emf) is proportional to the rotation speed of the motor 26 . Consequently, the back electromotive force (emf) of the motor 26 is represented by Equation 2 below.
Back electromotive force(emf)= k ×motor speed(rpm)+ b [Equation 2],
where, k and b are constants.
A voltage equation of the motor 26 may be derived from Equation 2, as represented by Equation 3 below.
Duty( V )= emf+R·I+L ·( di/dt ) [Equation 3],
where, duty is applied voltage, R is winding resistance, I is current of the motor, and L is inductance of the motor.
During the accelerated operation of the drum 10 , (di/dt)≈0, and the current of the motor 26 is a voltage dropping component proportional to the magnitude of the load. Consequently, Equation 3 may be changed to Equation 4.
Duty=back electromotive force(emf)+ C ·load [Equation 4]
Where, C is a constant.
On the assumption that a load of the drum 10 without the laundry 12 is L0, and a load of the laundry 12 is L, the total load is represented as follows: load=L0+L.
A duty applied with no load may be represented by Equation 5 below.
Duty(no load)=back electromotive force+ C·L 0=back electromotive force+ C 0 [Equation 5]
A duty applied with an arbitrary load may be represented by Equation 6 below.
Duty(arbitrary load)=back electromotive force+ C ·( L 0 +L )=back electromotive force+ C 0+ C 1=duty(no load)+ C 1 [Equation 6]
Consequently, when C1, a constant, is added to the no load duty, it is possible to estimate the duty with the arbitrary load, duty (arbitrary load).
FIG. 10 is a view illustrating an unbalance existing in the drum together with a uniform load. A rubber load 14 is mounted to the inner wall of the drum 10 , and a rubber unbalance 16 of 400 g, for example, is mounted to one side of the inner wall of the drum 10 .
FIG. 11 is a view illustrating a duty waveform during a laundry wrapping operation with the load and unbalance of FIG. 10 .
FIG. 11 illustrates a method of estimating C1 from an arbitrary load. N indicates the number of laundry wrapping attempts.
The actual duty (N) shows a duty trace of an arbitrary load having both the load 14 and the unbalance 16 as shown in FIG. 10 at an N th laundry wrapping attempt. The speed ripple is caused by the unbalance, and the duty trace appears in the reverse form of the speed ripple to control the speed ripple.
Next reference duty (N+1)=current reference duty (N)+c
Where, a is minimum value [actual duty (N)−reference duty (N)], b is maximum value [actual duty (N)−reference duty (N)], and c is (a+b)/2.
The duty trace with no load, i.e., the ‘duty (no load)’ may be acquired experimentally, and therefore, when N=0 in FIG. 10 , the duty trace with no load is used as an initial value of the reference duty, i.e., a reference duty ( 0 ).
However, the torque and current characteristics when the laundry 12 is actually put in the drum 10 are different.
For the laundry 12 , there exists a torque ripple due to the falling motion of the laundry 12 , as shown in FIG. 12 , before the laundry wrapping process is completed. Also, the laundry 12 is changed to the unbalanced state shown in FIG. 1 or the balanced state shown FIG. 2 , after the laundry wrapping process is completed.
FIG. 13 is a view illustrating a speed-current waveform when the balance is maintained by the laundry wrapping process at operation 104 of FIG. 6 .
Referring to FIG. 13 , the third rotation speed rpm 3 , which is between the first rotation speed rpm 1 and the second rotation speed rpm 2 , is a critical speed at which the laundry 12 starts to stick to the inner wall of the drum 10 . Generally, the laundry wrapping process is completed at the third rotation speed rpm 3 .
At the section where the speed of the drum 10 is the first rotation speed rpm 1 , a load torque T L increases due to the falling motion of the laundry 12 , with the result that larger current flows on average.
At the section where the speed of the drum 10 is accelerated from the first rotation speed rpm 1 to the second rotation speed rpm 2 , all the laundry 12 is brought into tight contact with the inner wall of the drum 10 the moment the speed of the drum 10 exceeds the third rotation speed rpm 3 . Consequently, the laundry 12 is changed to the torque term J·(dw/dt) by the inertia, not the load torque. When the acceleration from the first rotation speed rpm 1 to the second rotation speed rpm 2 is small, (dw/dt) converges to zero, and therefore, the torque current component by the acceleration approaches zero. Consequently, after the speed of the drum 10 exceeds the third rotation speed rpm 3 , the magnitude of the motor current to drive the drum 10 is much less than the current at the section where the drum is rotated at the first rotation speed rpm 1 .
FIG. 14 is a view illustrating a speed-current waveform when the balance is not maintained by the laundry wrapping process {circle around ( 2 )} at operation 104 of FIG. 6 .
Referring to FIG. 14 , a load torque T L increases due to the falling motion of the laundry 12 at the section where the speed of the drum 10 is the first rotation speed rpm 1 , with the result that larger current flows on average.
At the section where the speed of the drum 10 is accelerated from the first rotation speed rpm 1 to the second rotation speed rpm 2 , a speed ripple exists during one rotation of the drum 10 when the laundry 12 is distributed in the unbalanced state, as shown in FIG. 1 , after the speed of the drum 10 exceeds the third rotation speed rpm 3 . Since the control unit 22 increases current when the speed decreases, and decreases current when the speed increases, the speed ripple due to the unbalance induces a current ripple. At this time, the magnitude of the current ripple is proportional to the size of the unbalance.
The average current at the section where the speed of the drum 10 is greater than the third rotation speed rpm 3 is small, as in when the load is in the balanced state. However, the current ripple is very large. As a result, the minimum current value at the operation at which the speed of the drum 10 is between the third rotation speed rpm 3 and the second rotation speed rpm 2 is approximately zero.
Consequently, the control unit 22 detects the magnitude of the motor current through the current detecting unit 30 during the laundry wrapping process in which the speed of the drum 10 is accelerated from the first rotation speed rpm 1 to the second rotation speed rpm 2 ( 106 of FIG. 6 ). When the unbalance exists, the current ripple increases and the average current value decreases, with the result that the minimum current value is always approximately zero.
Subsequently, the control unit 22 determines whether the minimum value of the detected motor current is less than a predetermined current limit value ( 108 ). When it is determined that the minimum value of the motor current is less than the current limit value, the control unit 22 determines that the laundry is in the unbalanced state, and the procedure returns to operation 104 to reperform the laundry wrapping process {circle around ( 2 )} in which the drum 10 is rotated at the first rotation speed rpm 1 as shown in FIG. 5 .
When it is determined at operation 108 that the minimum value of the motor current is not less than the current limit value, the control unit 22 determines that the laundry is in the balanced state, and performs the laundry amount detecting process {circle around ( 3 )} to estimate the weight of the laundry 12 such that the weight of the laundry 12 is utilized as basic information to estimate an unbalance size using parameters, such as speed change and current ripple of the drum 10 , or set an allowable unbalance size before a high-speed spin-drying operation, as shown in FIG. 5 .
FIG. 15 is a view illustrating a duty waveform when the balance is maintained by the laundry wrapping process {circle around ( 2 )} at operation 204 of FIG. 7 , and FIG. 16 is a view illustrating a duty waveform when the balance is not maintained by the laundry wrapping process {circle around ( 2 )} at operation 204 of FIG. 7 .
Referring to FIGS. 15 and 16 , the third rotation speed rpm 3 , which is between the first rotation speed rpm 1 and the second rotation speed rpm 2 , is a critical speed at which the laundry 12 starts to stick to the inner wall of the drum 10 . Generally, the laundry wrapping process is completed at the third rotation speed rpm 3 .
When the laundry 12 is a load, the falling motion of the laundry exists at an operation section where the speed of the drum 10 is less than the third rotational speed rpm 3 . As a result, the average load torque and the torque change are very large as compared to when only the uniform load exists. Consequently, the duty waveform is larger than that of the reference duty, as shown at the section before the laundry wrapping process of FIG. 15 , and the change of the duty waveform is excessive.
When the speed of the drum 10 exceeds the third rotation speed rpm 3 , the laundry 12 sticks to the inner wall of the drum 10 , with the result that all the laundry 12 becomes an inertia load, and therefore, the average duty coincides with the reference duty. When the laundry 12 is distributed uniformly, little ripple component exists in the duty, as at the section before the laundry wrapping process of FIG. 15 . When the laundry 12 is distributed nonuniformly, on the other hand, a duty ripple having the same cycle as the rotational frequency of the drum 10 exists, as at the section after the laundry wrapping process of FIG. 16 .
Consequently, Equation 7 may be derived from the addition of the unbalanced component to Equation 3.
Duty=emf+ R· ( I LOAD +I Unb sin wt) [Equation 7],
where, I LOAD is the magnitude of the current ripple due to the uniform load, and I Unb is the magnitude of the current ripple due to the unbalance. The magnitude of the current ripple due to the unbalance is proportional to the unbalance amount.
Rearranging Equation 7,
Duty=emf+ R·I LOAD +R·I Unb ·sin wt=reference duty( N )+ R·I Unb ·sin wt
R·I Unb ·sin wt=duty−reference duty( N ) [Equation 8]
Accordingly, Min[duty−reference duty(N)]=−R·I Unb ,
where, R is a constant of the motor.
I Unb is proportional to the unbalance, and therefore, the minimum value (actual duty−reference duty) indicates the unbalance size.
Accordingly, an unbalance determination signal may be represented by Equation 9 below.
Unbalance determination signal=Min[actual duty(rpm)−reference duty(rpm)] [Equation 9]
Through the above-described operation, the control unit 22 generates an unbalance determination signal during the laundry wrapping process in which the speed of the drum 10 is accelerated from the first rotation speed rpm 1 to the second rotation speed rpm 2 ( 206 of FIG. 7 ), and determines whether the generated unbalance determination signal value is less than a predetermined unbalance limit value ( 208 ).
When it is determined at operation 208 that the unbalance determination signal value is less than the predetermined unbalance limit value, the control unit 22 determines that the laundry is in the unbalanced state, and the procedure returns to operation 204 to reperform the laundry wrapping process {circle around ( 2 )} in which the drum 10 is rotated at the first rotation speed rpm 1 as shown in FIG. 5 .
FIG. 17 is a view illustrating the trace of an unbalance determination signal when the load and the unbalance are changed.
It is not possible to confirm the size of a load during the laundry wrapping process {circle around ( 2 )}, and therefore, it is not possible to accurately limit the unbalance to a desired size. However, when the unbalance determination signal value is limited to an unbalance limit value equivalent to the unbalance level to be limited based on no load, as shown in FIG. 17 , it is possible to limit the unbalance to a larger size in proportion to the load.
For example, when the unbalance limit value is set such that the unbalance is limited to 200 g at the no load condition, the unbalance is limited to 250 g for a small-amount load, the unbalance is limited to 350 g for a middle-amount load, and the unbalance is limited to 450 g for a large-amount load.
When it is determined at operation 208 that the unbalance determination signal value is not less than the unbalance limit value, the control unit 22 determines that the laundry is in the balanced state, and performs the laundry amount detecting process {circle around ( 3 )} to estimate the weight of the laundry 12 such that the weight of the laundry 12 is utilized as basic information to estimate an unbalance size using parameters, such as speed change and current ripple of the drum 10 , or sets an allowable unbalance size before a high-speed spin-drying operation, as shown in FIG. 5 ( 210 ).
After the laundry amount detecting process {circle around ( 3 )} at operation 110 , 210 , the control unit 22 performs the unbalance detecting process {circle around ( 4 )} to estimate an unbalance size in the drum 10 using the estimated weight information and a control variable, such as a speed ripple or a current ripple, as shown in FIG. 5 ( 112 ) ( 212 ).
Subsequently, the control unit 22 determines whether the unbalance value estimated at the unbalance detecting process {circle around ( 4 )} is within an allowable value ( 114 ) ( 214 ). When it is determined that the estimated unbalance value is less than or equal to the allowable value, the control unit 22 performs the high-speed spin-drying process {circle around ( 5 )} to discharge moisture contained in the laundry 12 outside using a centrifugal force caused by rotating the drum 10 at a high speed, as shown in FIG. 5 ( 116 ) ( 216 ).
When it is determined at operation 114 , 214 that the estimated unbalance value is greater than the allowable value, the procedure returns to the laundry untangling process {circle around ( 1 )}, as in the conventional art, and then the unbalance reduction control procedure is repeated.
In the unbalance reduction control procedure according to the present embodiment, however, the balanced state of the laundry 12 is maintained during the laundry wrapping process {circle around ( 2 )}, with the result that the unbalance value estimated at the unbalance detecting process {circle around ( 4 )} is within the allowable value, and therefore, the procedure does not return to the laundry untangling process {circle around ( 1 )}.
FIG. 18 is a view illustrating an application example of a laundry wrapping process of a washing machine according to a second embodiment. Specifically, this drawing shows waveforms of the speed of the drum 10 , the actual duty, and the reference duty when the balanced state of the laundry is maintained after the laundry wrapping process is reperformed once.
As apparent from the above description, the washing machine according to the present embodiments and the control method thereof provide the following effects. It is possible to reduce the unbalance reduction control time to maintain the balanced state of the laundry through the improved laundry wrapping operation, thereby reducing a total spin-drying time. Also, it is possible to determine the unbalanced state of the laundry in real time, during the laundry wrapping process, and, when the laundry is unbalanced, to reperform only the laundry wrapping process, thereby greatly improving the laundry wrapping success rate and thus greatly reducing the total unbalance reduction control time.
Furthermore, it is possible to determine the unbalanced state of the laundry using duty information (voltage command value) obtained from the difference between the actual duty and the reference duty. Consequently, the present embodiments are applicable to a motor controller having no current detection circuit.
Although a few embodiments have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.
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Disclosed herein are a washing machine that is capable of maintaining the balanced state of laundry to more smoothly perform a spin-drying operation and a control method thereof. The control method of the washing machine including a drum to receive laundry and a motor to rotate the drum to reduce unbalance generated due to the nonuniform distribution of the laundry, includes wrapping the laundry by accelerating the drum such that the laundry sticks to an inner wall of the drum, detecting motor current during the wrapping of the laundry, determining an unbalanced state of the laundry based on the detected motor current, and controlling speed of the drum based on a result of the determination.
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FIELD OF THE INVENTION
[0001] The invention relates to the emission of X rays, or of particles, particularly protons and electrons, and more particularly to the manufacturing of targets used in such an emission.
BACKGROUND
[0002] A known principle of X-ray generation comprises focusing a laser beam on a solid metal target, preferably a metal having a high atomic number, for example, gold, copper, or any other dense metal. The interaction of the laser beam and of the metal thus generates a plasma and a mono-energetic X-ray emission, which are particularly used in mammography or angiography. The target is generally placed in a vacuum enclosure, where the laser/matter interaction takes place, and is mounted on a mobile support, for example, a rotating support, so that each laser firing impacts a portion of the target which has not been impacted by a previous tiring.
[0003] When the metal target has a large thickness, particularly greater than 500 nanometer, the X rays are emitted in the half-space where the laser beam propagates. It is then spoken of a “retro-emission”. However, when the metal target has a small thickness, particularly a thickness smaller than 500 nanometers, the rays are emitted in the direction of the laser beam and are accordingly emitted by the surface of the metal target opposite to that impacted by the laser beam. It is then spoken of a “transmission” emission.
[0004] Usually, thin metal targets are obtained by depositing a metal layer on a copper or plastic support, after which the substrate is removed by means of a chemical bath and/or of a plasma etching. The layer thus exposed is then washed, for example, in water or alcohol, to remove a maximum amount of impurities, after which the target is mounted on the mobile support, and the support is mounted in the enclosure.
[0005] Such a manufacturing is long and the substrate removal step is besides very delicate. It is further necessary to introduce the target and its support into the enclosure, which assumes breaking the vacuum existing therein, and then reforming the vacuum, which also takes a long time. In practice, the time of use of an X-ray emission system is very limited, and its down time is long.
[0006] Similar problems are posed for the generation of particles, for example, electrons and protons, by means of a laser firing on a thin target.
BRIEF DESCRIPTION OF THE INVENTION
[0007] The present invention aims at providing a method of manufacturing a target for the generation of photon or particle radiation, particularly the generation of X rays, electrons, or protons, which does not require removing a physical support of the metal target, and which can be directly used in a vacuum enclosure, and particularly the vacuum enclosure used for the radiation or particle emission.
[0008] For this purpose, the invention aims at a method of manufacturing a target for the generation of photon or particle radiations by means of a laser, comprising:
forming a support comprising a first and a second surfaces and crossed by openings; and forming in a tight enclosure a layer of material on the first surface of the support.
[0011] According to the invention, the forming of the layer of material on the support comprises:
protecting the first surface of the support with a protection element; injecting into the enclosure a gas of filling material; adjusting the pressure in the enclosure and the temperature of the support to form solid plugs of filling material in the openings of the support; stopping the injection of the gas of filling material into the enclosure; maintaining the temperature of the support and the pressure in the enclosure at values maintaining the plugs solid in the openings of the support, and jointly to said maintaining:
withdrawing the protection element from the first surface of the support to expose said surface; and forming the layer of material on he first surface of the support and on the solid plugs filling the openings;
modifying the conditions of pressure in the enclosure and of support temperature to clear the openings of the support of the solid plugs.
[0020] In other words, a solid support is formed by filling preexisting openings of the support, the layer, for example, metallic, forming the target is formed on the solid support thus created, after which the material for filling the openings is removed. The portions of the metal layer covering the openings then form the areas of the target which are subsequently impacted by the laser beam to produce rays (X) or particles (protons or electrons). The support is thus not removed and may for example directly be the mobile support used to expose to the laser beam areas of the target which are free or any impact. Further, the filling material in solid form may be easily removed once the layer has been deposited, for example, by modifying the pressure in the enclosure and/or the support temperature to sublimate the filling material.
[0021] Further, the filling material may be introduced in gaseous form into the vacuum enclosure used for the emission of rays or particles, and the layer of material may be directly formed in this enclosure by means, for example, of a physical vapor deposition.
[0022] According to an embodiment, the first surface of the support is planar, and the protection thereof comprises placing the first surface of the support against a planar solid surface.
[0023] According to an embodiment, the placing of the support in contact with the gas comprises placing the support in a tight enclosure have a predetermined low pressure and cooling the support to a temperature lower than the temperature of the triple point of the material forming the gas.
[0024] According to an embodiment, the layer of material is deposited on the first surface of the support by means of a physical vapor deposition. The vapor phase of the metal is for example produced by the ohmic heating of a support having a solid mass of the metal resting thereon or by the electronic bombarding of a target made of the metal.
[0025] Particularly, the tight enclosure comprises means capable of injecting the gas into the enclosure, means capable of adjusting the internal pressure thereof, means capable of adjusting the temperature of the support to temperatures lower than the triple point of the material forming the gas, and means capable of vaporizing a solid metal element placed in contact therewith. Further, the placing into contact of the support with the gas, the forming of the plugs filling the support openings, and the physical vapor deposition are performed in the enclosure by maintaining a low pressure, particularly lower than 10 −3 mbar.
[0026] According to an embodiment, the withdrawal of the protection element from the first surface of the support comprises heating said support to separate the element from the solid plugs filling the openings of the support and drawing the protection element away from the first surface of the support.
[0027] According to an embodiment, the clearing of the support openings comprises adjusting the support temperature and/or the pressure in the enclosure. Particularly, the support is re-heated above the sublimation point of the filling material and the enclosure is maintained at a pressure lower than the saturation pressure corresponding to the support temperature.
[0028] According to an embodiment, the filling material is argon, nitrogen, krypton, or xenon.
[0029] According to an embodiment, the layer of material is metallic. More specifically, the thickness of the layer of metallic material is smaller than or equal to 500 nanometers, and preferably smaller than or equal to 50 nanometers.
[0030] As a variation, a layer of material comprises a metal layer and a dihydrogen or deuterium layer. More specifically, the metal layer has a thickness in the range from 20 nanometers to 100 nanometers, and the dihydrogen or deuterium layer has a thickness in the range from 20 nanometers to 100 nanometers.
[0031] According to an embodiment, the openings of the support are truncated cones widening from the first surface of the support to the second surface of the support.
[0032] According to an embodiment, openings of the support are arranged in a circle and angularly spaced apart in regular fashion.
[0033] The invention also aims at a system for implementing a method of manufacturing a target for the generation of radiation, particularly X rays or particles, particularly of protons or electrons by means of a laser, of the previously-mentioned type, comprising:
a tight enclosure; a support and means for positioning the support in the enclosure; a protection element and means for positioning the protection element in the enclosure between a withdrawal position and a position where the protection element is placed against the surface of the support; means for pumping the internal volume of the enclosure; means for controlling the support temperature; means for injecting gas into the enclosure; means for heating the protection element; and means for vaporizing a metallic element in the enclosure.
[0042] According to an embodiment, the means for positioning the support in the enclosure comprise means for rotating said support.
[0043] According to an embodiment, the enclosure comprises a window transparent to the laser beam arranged in front of the support surface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0044] The present invention will be better understood on reading of the following description provided as an example only in relation with the accompanying drawings, where the same reference numerals designate the same or similar elements, among which:
[0045] FIG. 1 is a simplified view of a system according to the invention for producing a target for X rays and for producing X rays;
[0046] FIGS. 2 and 3 respectively are simplified top and cross-section views of a support for a target according to the invention;
[0047] FIGS. 4 to 9 are simplified views illustrating different phases of the operation of the system of FIG. 1 to implement a method according to the invention; and
[0048] FIG. 10 shows saturation curves of different gases of filling material for temperatures lower than the triple point of these gases.
DETAILED DESCRIPTION
[0049] In relation with FIG. 1 , a system 10 according to the invention enabling to form a metal target for the generation of X rays and to generate X rays from a single vacuum enclosure will now be described.
[0050] System 10 particularly comprises:
a tight enclosure 12 comprising a first wall portion forming a first window 14 transparent to a laser beam, and a second wall portion forming a second window 16 transparent to X rays and arranged in front of first window 14 . Tight enclosure 12 further comprises a heat shield enabling to limit heat inputs by radiation from the surrounding environment and from the elements internal to the enclosure having their temperature maintained high, for example, close to 300 K, for their operation. a pumping circuit 18 of enclosure 12 , capable of creating therein a low pressure, particularly lower than 10 −3 mbar, and more particularly a pressure lower than or equal to 10 −4 mbar; an injection circuit 20 capable of injecting gas into enclosure 12 ; a circuit 22 for controlling the temperature of enclosure 12 capable of establishing in enclosure 12 a low temperature, particularly a temperature lower than 100 K. Advantageously, circuit 22 also comprises a cold source, preferably having a temperature lower than the temperature of the triple point of a filling material, capable of discharging the heat flows generated in enclosure 12 , particularly the flows generated by a process of deposition of a metal layer formed in enclosure 12 , as will be described in further detail hereafter; and a laser 24 capable of performing laser firings through first window 14 along a beam axis 26 .
[0056] System 10 also comprises, in enclosure 12 :
a planar support 28 thoroughly crossed by openings 30 ; a first circuit for displacing support 32 capable of displacing said support to position each of openings 30 on laser beam axis 26 , as will be explained in further detail hereafter; a solid plate 34 , for example of same dimensions as support 28 ; a second displacement and heating circuit 36 , capable of displacing plate 34 between a storage position, where plate 34 does not disturb the subsequent deposition of a metal layer on support 28 , and a protection position, where plate 34 is placed against support 28 to close openings 30 and prevent the condensation on the surface of support 28 having plate 34 placed against it. Circuit 36 is further capable of heating plate 34 . Circuit 36 is for example capable of delivering a heat pulse to plate 34 and/or plate 34 is metallic and circuit 36 is capable of injecting a current therein to cause a heating by Joule effect; a support 38 capable of receiving a metal layer to be evaporated; and a circuit 40 for heating support 38 to take the support to a temperature greater than the evaporation temperature of the metal deposited on support 38 .
[0063] Temperature control circuit 22 also comprises a circuit for controlling the temperature of support 28 , and particularly means for cooling support 28 , for example, ducts in contact therewith, and/or inside thereof, and having gaseous helium flowing therethrough, and/or a cryorefrigerator comprising a connection by metal braids or by thermosyphon, and means for heating support 28 , for example a regulated electric heating.
[0064] Finally, system 10 comprises a unit 42 controlling the operation of the elements which have just been described according to a plurality of phases described hereafter.
[0065] Referring to FIGS. 2 and 3 , support 28 for example takes the shape of a disk where openings 30 are positioned in a circle and angularly spaced apart in regular fashion. Advantageously, openings 30 have millimetric or submillimetric dimensions and have a truncated cone cross-section which widens from surface 44 of support 28 facing window 14 of enclosure 12 to surface 46 facing window 16 of enclosure 12 , to conform to the angle of divergence of the X-ray beam produced on impact of laser firings.
[0066] Advantageously, support 28 is made of silicon or germanium, such materials being very good heat conductors, which enables to easily control the support temperature. Further, a silicon or germanium support may be significantly polished. More specifically, surface 44 of support 28 is polished to have very few roughnesses, and particularly to have a so-called “optical quality” polish, which provides a subsequent metal deposition on surface 44 of substantially constant thickness.
[0067] Circuit 32 for displacing support 28 for example comprises a step-by-step electric motor to rotate support 28 around an axis 48 perpendicular to the main plane of support 28 , and running through the center of the circle having openings 30 positioned thereon. Circuit 32 thus enables to position each of openings 30 on axis 26 of the laser beam emitted by laser 24 .
[0068] In relation with FIGS. 4 to 9 , a method according to the invention of forming a metal target for the generation of X rays and generating the X rays implemented by system 10 will now be described.
[0069] In a first step of the method, a metal layer 60 is positioned on support 38 , the metal of layer 60 being that forming the target for the subsequently performed X-ray generation ( FIG. 4 ). The metal of layer 60 is for example tantalum, tungsten, gold, or copper. Control unit 42 further controls displacement and heating circuit 36 to place plate 34 against support 28 .
[0070] Consecutively or simultaneously, unit 42 controls pumping circuit 18 and temperature control circuit 22 to create and maintain a pressure and a temperature in enclosure 12 such that:
support 28 and plate 34 have a temperature lower than the temperature of the triple point of a material for filling openings 30 subsequently introduced into enclosure 12 in gaseous form; and the pressure in enclosure 12 is maintained at a pressure lower than the saturation vapor pressure of the filling material corresponding to the temperature of support 28 to avoid any parasitic condensation.
[0073] Once the pressure and the temperature of enclosure 12 have been adjusted, unit 42 then controls injection circuit 20 so that the latter injects into enclosure 12 filling material 62 in gaseous form. Filling material 62 particularly is argon, nitrogen, krypton, xenon, or a mixture thereof. Due to the pressure and temperature conditions in enclosure 12 which are adjusted according to injected gas 62 , the latter condenses in solid form in openings 30 .
[0074] Once openings 30 have been filled with solid material 62 , unit 42 controls the stopping of the gas injection into enclosure 12 . Advantageously, unit 42 controls pumping circuit 18 to lower the pressure in enclosure 12 and temperature control circuit 22 to lower the temperature of support 28 by a few Kelvin to guarantee the maintaining of the plugs in the solid state during a subsequent heat inflow from plate 34 and a metal deposition on support 28 and avoid the self-evaporation of the plugs.
[0075] Unit 42 then controls displacement and heating circuit 36 so that it heats plate 34 . Plate 34 then separates from material 62 filling openings 30 of support 28 ( FIG. 5 ). Unit 42 then controls displacement and heating circuit 36 to position plate 34 in its storage posit ( FIG. 6 ).
[0076] In a next step, unit 42 controls heating circuit 40 so that the temperature of support 38 is higher than the evaporation temperature of the metal of layer 60 laid on support 38 . A physical vapor deposition is then implemented. More specifically, vaporized metal 64 deposits on surface 44 of support 28 and on plugs 62 of solid material filling openings 30 ( FIG. 7 ), thus forming a metal layer 66 .
[0077] Once the thickness desired for metal layer 66 has been obtained, particularly a thickness smaller than or equal than 500 nanometers, and preferably a thickness smaller than or equal to 50 nanometers, to implement an X-ray emission by transmission, unit 42 controls the stopping of the heating of support 38 and accordingly the stopping of the metal deposition on support 28 . Unit 42 then controls pumping circuit 18 and temperature control circuit 22 to remove material 62 tilling openings 30 of support 28 , preferably by sublimation. More specifically, unit 42 controls circuit 22 to adjust the temperature of support 28 to a temperature greater than the saturation vapor temperature of the filling material corresponding to the pressure in enclosure 12 maintained constant. Thus, the temperature of the solid plugs crosses the saturation vapor pressure curve of the filling material as illustrated in FIG. 10 , so that the solid plugs sublimate. Sublimated material 68 is then pumped by pumping circuit 18 and discharged from enclosure 12 ( FIG. 8 ).
[0078] Finally, once openings 30 have been cleared of tilling material 62 , unit 42 controls laser 24 and displacement circuit 32 to cause laser firings 70 through window 14 on the portions of metal layer 66 arranged on openings 30 of support 28 , particularly on portions which have received no impact. For each laser firing, a beam of monochromatic X-rays 72 is then generated along axis 26 of the laser beam, said beam being emitted towards the outside of enclosure 12 through window 16 .
[0079] For example, for a filling material formed of argon, the temperature of support 28 and of plate 34 is selected from range [30 K, 40 K] and the pressure of the enclosure is substantially selected to be equal to 10 −4 mbar.
[0080] Advantageously, the selection of the filling material and the selection of the adjustments of the pressure in the enclosure and of the support temperature are performed as follows. First, the filling material is selected according to support 28 to obtain a homogeneous metal deposition. Particularly, if the support comprises a crystal lattice, the filling material is selected so that its solid phase is also crystalline so that the metal target deposition is performed on a homogeneous surface.
[0081] Once the filling material has been selected, the support temperature is selected for a pressure in the enclosure lower than 10 −3 mbar, for example, 25 K for nitrogen, 35 K for argon, 52 K for xenon, or 75 K for krypton, and the gas of filling material is introduced into the enclosure. The pressure in the enclosure is thus increased, particularly to be in the range from 10 −3 mbar to 5.10 −3 mbar to solidify the gas and till the support openings. Once the openings have been filled, the gas injection is stopped and the pressure is lowered back to a value lower than 10 −3 mbar.
[0082] During the metal deposition of the target on the support, the temperature is lowered by a few Kelvin and the pressure in the enclosure is lowered by some 10 −4 mbar to limit phenomena of evaporation by heat inflow and self-evaporation. When the deposition of the target on the support is finished, the support temperature is then raised by a few Kelvin to cause the sublimation of the filling material present in the openings.
[0083] In a first variation, when target 66 is worn out, enclosure 12 is opened and support 28 is removed along with worn-out target 66 . A new support 28 is then introduced into enclosure 12 for a new target manufacturing and X-ray production cycle, as described previously.
[0084] In a second variation, circuit 22 for controlling the temperature of support 28 is capable of raising the temperature thereof to cause the total evaporation of worn-out target 66 . The evaporated metal is then pumped by pumping circuit 18 and a new target manufacturing cycle can then be implemented without having to break the vacuum in enclosure 12 .
[0085] A specific embodiment where the target support comprises openings according to a specific arrangement has been described. Of course, the invention applies to any type of support and of opening arrangement.
[0086] A plate which is placed against the support during the filling of the openings to, particularly, protect the surface of the support having the condensation target subsequently deposited thereon, has been described. Other protection elements may however be envisaged. Particularly, a second mobile protection element, for example, a second solid plate, is provided to be placed against the surface of support 28 opposite to the surface against which protection element 34 is capable of being placed. The second protection element is placed against support 28 on deposition of the metal layer to protect the rear surface from a parasitic deposition on the plugs filling openings 30 . The second protection element is advantageously connected to a displacement and heating circuit for displacing and heating said circuit.
[0087] Similarly, an embodiment where the forming of the solid plugs in the openings of the target support, the withdrawal of the protection plate, and the deposition of the target on the support are carried out at a constant pressure and temperature has been described. During these phases, the pressure and the temperature may vary within a whole range enabling to keep the plugs tilling the support openings in their solid form. Similarly, different temperatures and pressures may be selected during the X-ray generation.
[0088] The deposition of a single metallic material on support 28 has been described. As a variation, a plurality of metal layers are successively deposited on support 28 . For this purpose, the system according to the invention for example comprises several supports 38 having their temperature controlled independently from one another by a heating circuit 40 provided for and connected to each support 38 or by a single heating circuit 40 connected to each support 38 . Different metallic materials may thus be deposited on supports 38 , and unit 42 controls heating circuit 40 to deposit successive metallic layers on support 28 in a predetermined order. Once the deposition of the different metal layers has been performed, the filling material present in openings 30 of support 28 is then removed, as described previously, and the laser firings can take place.
[0089] As a variation or additionally, once the metal layer has been deposited, for example, first layer, the second protection element is placed against support 28 , for example, after the plugs filling openings 30 of support 28 have been removed, before the deposition of the next metal layer(s), which particularly avoids the deposition of metal in openings 30 . Thereby, the deposition conditions are less restrictive since it is no longer necessary to adjust the pressure and the temperature in the enclosure to keep the plugs solid.
[0090] For example, the next metal layer(s) may be deposited by condensation in solid form of a gas injected into the enclosure via injection circuit 20 , the pressure and the temperature of the enclosure being controlled to obtain such a condensation.
[0091] The forming of a metal target for the generation of X rays has been described. The invention also applies to the manufacturing of non-metal or partially metallic ultra-thin targets, such as for example targets used in particle accelerators. For example, the targets comprise a solid deuterium or dihydrogen layer in addition to or instead of a metal layer. Laser firings on such a target thus generate protons and/or electrons.
[0092] Particularly, a metal layer, having a thickness between 20 nanometers and 100 nanometers, is deposited on support 28 , after which a second solid deuterium or dihydrogen layer, having a thickness between 20 nanometers and 100 nanometers, is deposited on the metal layer. The deposition of multiple materials on support 28 is for example performed by depositing the dihydrogen or deuterium layer on the metal layer once the plugs filling openings 30 have been removed and the second protection element has been placed against support 28 .
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A method of manufacturing a target for the generation of radiation of photons, protons or electrons by means of a laser, including: forming a support including first and second surfaces connected by openings, and forming in an enclosure a layer of material on the first surface by protecting the first surface with a protection element, injecting into the enclosure a gas of filling material, adjusting the pressure in the enclosure and the temperature of the support to form plugs of material in the openings of the support, and maintaining the temperature of the support and the pressure in the enclosure at values to maintain the plugs, followed by withdrawing the protection clement from the first surface, and forming a layer of metallic material on the first surface of the support and on the plugs. The pressure and support temperature are then modified to remove the plugs.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of now abandoned application Ser. No. 700,337, filed June 28th, 1976, which, in turn, is a streamline continuation of application Ser. No. 557,811, filed on Mar. 28th, 1975, and now abandoned, and which, in turn, is a streamline continuation application of application Ser. No. 269,723, filed July 7, 1972, and now abandoned.
FIELD AND BACKGROUND OF THE INVENTION
This invention relates to devices for removing solid pollutants from steam and gases evolved during coke quenching operations and, more particularly, to a new and useful device, for this purpose, which may be adjustably positioned in a stack located above the site of a coke quenching operation for flow of the steam and gases therethrough, the device including baffle means for removing the solid pollutants from the steam and gases and spraying means, operable between successive coke quenching operations, to flush the trapped solid pollutants from the baffle means. Still more particularly, it is desired to emphasize that the present invention is not directed to a coke quenching tower, but rather to an improved means, positioned in a stack receiving steam and gases, evolved during a coke quenching operation below the stack, to remove solid pollutants, such as coke particles and dust, from the steam and gases before the latter are discharged from the stack to atmosphere, with the baffle structure of the device being flushed, by spraying means, between successive coke quenching operations.
At the present time, it is known to provide devices in the discharge stacks of coke quenching towers, for separating solid pollutants and water from the quenching vapors evolved in a coke quenching tower during coke quenching. The known devices include baffling to cause the steam and gases to move in a tortuous path for the purpose of removing solid pollutants from the steam and gases. Some of the baffle arrangements include a louver-like structure constituted by individual blades having noses or ribs located to deflect the gases in a desirable manner. In the known constructions, the ribs are formed on both an upper and a lower set of blades so that they extend uniformly toward the bottom-right or the bottom-left side of the stack, with the result that the quantity of pollutants separated thereby amounts approximately to 130 grams per ton of coke for an initial content, of the gases or steam, of about 400 grams per ton of coke.
It is important that a distinction be made between coke quenching towers and cooling towers or stacks for discharging the gases and steam evolved during quenching of incandescent coke in the quenching towers. Thus, in a coke quenching tower, the incandescent coke is sprayed with water to cool the coke and this spraying operation results in the evolution of steam and gases. The steam and gases leaving the coke quenching tower pass upwardly through a cooling tower or stack for discharge to atmosphere. It is in the cooling tower or stack, as distinguished from the coke quenching tower per se, that the devices are arranged for separating solid pollutants from the steam and gases moving upwardly through the cooling tower or stack for discharge to atmosphere. This pollutant separation operation is entirely distinct from the coke quenching operation, and the cooling tower or stack, and the baffle means or the like arranged therein, play no part in the actual quenching of the incandescent coke, which occurs in the quenching tower located below the discharge stack or cooling tower.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided an improved structure which is adjustable in length and is adjustably positionable in the cooling tower or stack serving, for discharge to atmosphere, of the steam and gases evolved during a coke quenching operation in a coke quenching tower. The improved structure includes a louvered panel set for removing and trapping the solid pollutants from the gas and steam discharged to atmosphere through the cooling tower or stack, and also includes a spray arrangement operable, in between successive coke quenching operations, to flush the trapped solid pollutants, such as coke particles and dust, from the louvered panel set.
The present invention provides a means for removing, from the coke quenching vapors, a quantity of dust and other solid pollutants which is considerably higher than that possible heretofore, and which means may be adapted to a particular rate of discharge of the vapors from the device.
To this end, the invention provides an arrangement of a support structure which includes a baffle arrangement or structure of louvered panels, provided with upper and lower sets of panels or baffles having noses or offset ends which, in the upper set, are directed outwardly and, in the lower set are directed inwardly. The support structure further includes a conduit, which may be formed to a selected length, and which carries a plurality of spray nozzles along its length. In the interval between two successive coke quenching operations, this conduit is supplied with a spraying liquid, such as water, which flushes the trapped solid pollutants from the baffle arrangement or louvered panels arranged above the spray nozzles. The two blade sets or arrangements form a sort of double-louvered panel. Advantageously, the dust-catching louvered panels are mounted in the stack in the shape of a roof with the ridge in the axial plane of the stack.
The louvered panel may be constructed of wood, plastic, or similar material, and preferably a polypropylene or a material containing polypropylene may be used. The structure may be positioned adjustably to extend across the stack, or across a support in the stack, in the upper part of the stack, and the angle at which the structure extends across the stack may be set in accordance with the flow rate of the steam and gases being discharged from the quenching tower to flow upwardly through the stack. In order to change the angle at which the structure extends across the stack, it is necessary only to increase or decrease its length, as by adding or substracting sections, for example, and to shift a diagonal brace which supports the structure from a wall of the stack.
With a solid pollutant removing structure embodying the invention, the content of the solid pollutants, in the steam or gases evolved during quenching of the coke, may be reduced from 400 grams per ton of coke to 63 grams per ton of coke or from 250 grams per ton of coke to 47 grams, as indicated by tests which have been carried out according to the rules of the German Mining Authority. These results are attained when using baffle blades of polypropylene and having nose-ribs.
There is no definite explanation as to how this favorable effect is produced, but it is certain, especially when the baffles are constructed of polypropylene or the like, that an electrostatic charging of the blades and the formation of inhomogeneous electrical fields between the blades, takes place. The electrostatic charging of the blades is caused by the steam and gases evolved from the glowing coke in the first seconds of the quenching operation, and which contains the main quantity of the solid pollutants. While steam and gases are flowing upwardly through the stack from the quenching tower, the upwardly flowing stream charges the blades electrostatically by friction, and it can be assumed that, in the inhomogenous electrical fields, the unlike-charged dirt-particles are deposited on the blades and particularly in the included angle between the blades and their nose-ribs. In the subsequent phases of the coke quenching operation, moist vapors impinge on the blades and the electrical fields are broken down.
However, it is also possible that the unequal orientation of the nose ribs, in the different arrangements or sets of blades, produces favorable conditions for the dirt-deposit and for the condensation of water. Probably both effects act conjointly and increase each other.
The feature of the invention, involving the arrangement of the panel on a support beam which extends obliquely across the stack or cooling tower, permits a ready adaptation of the cleaning apparatus to the flow rate of the steam and gases upwardly through the stack. The support beam is supported on guide elements which are arranged adjacent the interior casing of the stack. They also may be supported from above, by longitudinal retaining ledges that are, in turn, secured by transverse connecting ledges and fixed to the longitudinal supporting structure by means of a clamping bolt.
To adjust the structure in accordance with the rate of flow of the gases, the structure may be either lengthened or shortened by merely adding or subtracting individual louver frames mounted on the support beam structure, and by correspondingly lengthening or shortening the feed lines for the spray nozzles, as by means for providing flexible interconnecting sections, for example. In one embodiment, this can be accomplished by adding or removing an entire louvered panel set, and then the inclination of the support beam is increased in order to accommodate an added louvered panel set. When a panel set is removed, the inclination of the support beam is decreased.
In one embodiment of the invention, the overall structure is supported in the discharge stack leading from a coke quenching tower by providing two vertically extending supports, which are opposite each other in the stack. The overall structure is then pivoted at one end to one of these vertically extending supports and anchored, at the other end, to the other vertically extending support, by a pin or bolt or the like. Either end may be pivoted to a vertically extending support, with the other and being anchored to a vertically extending support. In this modification, a diagonal brace extends, from that vertically extending support to which the overall structure is pivoted, to the overall structure. Flexible connections are provided in or to a feed line mounted on the support structure and provided with spray nozzles for flushing the louvered panels in between successive coke quenching operations, the supply of flushing liquid, such as water, being interrupted during a coke quenching operation. The effective area of the device, across the path of flow of the steam and gases, is a maximum at the largest inclination from the horizontal and is a minimum when the device is disposed to extend horizontally across the stack.
In a modified embodiment of the invention, the support structure comprises pairs of support beam sections arranged in spaced parallel relation for longitudinal movement relative to each other to increase and decrease the length of the support structure. Each beam section of a pair of carries a roller engaged with the other beam section of the same pair. One beam section of each pair is pivotally connected to a support extending vertically inside the stack, and the other beam section of each pair is connected to a roller movable in a vertical guide way opposite the vertical support and again arranged on the inner surface of the stack. A cable and winch arrangement is provided for pivoting the support structure to various angular positions, and the pairs of support beam sections automatically vary in effective length in accordance with the inclination of the device in the stack.
A series of individual louvered panels are supported on the two beam sections of each pair, and may be readily and easily removed therefrom or added thereto in accordance with the overall width or dimensions desired which, in turn, is dependent upon the angle of inclination. Spray pipes are supported by straps from the two support beam sections of each pair, and are supplied with flushing water through a feed line connected by tees to each of the spray pipes, the feed line including flexible conduit sections to accommodate the pivoting of the device within the stack.
In both embodiments of the invention, the individual louvered blades are inserted in slots in longitudinally extending, vertically oriented support plates supported either directly or indirectly on support bars which, in turn, are supported on the pairs of support beams. The support plates, as well as the individual blades, may be formed of a suitable plastic composition material such as, for example, polypropylene. Clamping means are provided to hold the panels, and particularly the individual blades, firmly engaged with the supports of each panel so that the blades or baffles are held stationarily in the support plates. As in the first mentioned embodiment, the flow area of the device may be increased or decreased, in accordance with its angular disposition in the stack, by adding or removing individual louvered panels. The individual louvered panels have a length which is only a minor fraction of the transverse dimension of the stack, so that a number of individual louvered panels are necessary in order to have the device extend completely across the flow area upwardly through the stack, the number depending, again, upon the angular orientation of the device in the stack, and which may vary, in either direction, from a horizontal orientation providing the smallest area of the solid pollutant trapping device, to a maximum angle of inclination providing a maximum area of the solid-pollutant removing device.
The apparatus or device of the invention may be erected in already existing stacks for coke quenching towers. In some instances, it may be desirable or necessary to widen the existing stack sections conically on one, two, or all sides in order to reduce draft losses to a minimum.
An object of the invention is to provide an improved device for separating solid pollutants from steam and gases evolved during coke quenching operations.
Another object of the invention is to provide such a device including a flushing system arranged to flush the solid pollutants trapped by the device, between successive coke quenching operations.
A further object of the invention is to provide such a device which is readily adjustable in length to vary its effective area, when mounted in a stack for discharge of steam and gases evolved during quenching of coke in a coke-quenching tower.
Yet another object of the invention is to provide such a device which may be disposed to extend across the stack at any desired angle varying from a horizontal orientation in either direction in order to vary the effective area of the device to correspond to various flow rates of the steam and gases upwardly through the stack.
A further object of the invention is to provide such an improved device which is simple in design, rugged in construction and economical to manufacture.
For an understanding of the principles of the invention, reference is made to the following description of typical embodiments thereof as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the Drawings:
FIG. 1 is a partial side elevational view of a louvered panel forming part of a device for separating solid pollutants from steam and gases evolved during a coke quenching operation, in accordance with one embodiment of the invention;
FIG. 2 is a partial top plan view of the device shown in FIG. 1;
FIG. 3 is a partial sectional view through a stack for discharging steam and gases evolved during a coke quenching operation in a coke quenching tower, and illustrating the device of FIG. 1 as mounted in a stack and adjustable to various inclinations;
FIG. 4 is a view similar to FIG. 3 illustrating another embodiment of the invention;
FIG. 5 is a partial elevational view, to an enlarged scale, of the upper left-hand portion of the device shown in FIG. 4;
FIG. 6 is a sectional view taken on the line VI--VI of FIG. 5;
FIG. 7 is an enlarged partial side elevation view illustrating one interconnection between the support beams of a pair;
FIG. 8 is a sectional view taken on the line VIII--VIII of FIG. 7;
FIG. 9 is a view similar to FIG. 7 illustrating the other interconnection of the two support beams of a pair;
FIG. 10 is a sectional view taken on the line X--X of FIG. 9;
FIG. 11 is a view, partly in section, taken on the line XI--XI of FIG. 12 and illustrating, to a larger scale, the construction of a louvered panel;
FIG. 12 is an elevation view, partly in section, taken on the lines XII--XII of FIG. 11;
FIG. 13 is a view, similar to FIG. 4, illustrating the device of FIG. 4 in another angular orientation in the stack; and
FIGS. 14, 15 and 16 are partial perspective views, partly in section, illustrating details of the louvered panels.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to the embodiment of the invention shown in FIGS. 1, 2, and 3, and particularly to FIG. 3, the device embodying the invention, and operable to separate solid pollutants from steam and gas evolved during a coke quenching operation, is illustrated as mounted in the stack leading from a coke quenching tower and serving to discharge the steam and gas evolved during the coke quenching operation, the coke quenching tower being disposed below the stack and not being shown in the drawings. In the particular embodiment shown, the discharge stack includes a casing support structure 15 and an upright casing 16. Casing 16 is provided with a device supporting structure for the solid pollutants separating device of the invention, and this supporting structure is in the form of vertically extending support beams 14, 14 engaging inner surfaces of the casing 16.
The device includes two or more main support beams 13, having opposite ends 24 and 26. In the solid line position shown in FIG. 3, the support beams 13 are pivoted or otherwise connected at their ends 26 to locations along the right-hand vertical beam or column 14, and they are anchored, by a pin or the like, to locations along the left-hand vertical beam or column 14. The device thus may be pivoted, about a pivot or pin 26a, between the position indicated in solid lines and the several positions 13', 13" and 13'" indicated by dotted lines, with the lengths of the beams 13 being suitably selected in accordance with the particular angular orientation of the device. The position 13', in which the support beams 13 extend horizontally, is the minimum width position, whereas the positions 13" and 13'" indicate inclination angles respectively less than and more than the inclination of the beams 13 in the solid line position.
Alternatively, the support beams 13 may be pivotally connected at their ends 24 to locations along the left-hand vertical beam or column 14 and connected by a pin or the like at their ends 26 to locations along the right-hand vertical beam or column 14. In this arrangement, the device may be pivoted about pivots 24a at the ends 24 of the support beams 13, from the position shown in solid lines to the positions indicated, for example, at 13b and 13b'. The effective widths or areas of the device, for trapping solid pollutants in the steam and gases flowing upwardly through the casing 16, increase with the degree of inclination from the horizontal. Thus, one of the intermediate positions, namely the position 13 shown in solid lines, provides a flow area for the gases or steam therethrough which is slightly less than the maximum position indicated at 13'".
In accordance with the invention, the support beams 13 support a plurality of louvered panels 9, 9', 9" and 9'", as well as a spray pipe 11 having discharge orifices 12 directed toward the louvered panels. While four louvered panels are shown in FIG. 3, the number may be more or less in dependence on the inclination of the device to the horizontal. The spray nozzles 12 are arranged at regular intervals, and the pipe 11 may comprise several sections interconnected by flexible conduits to accommodate adjustments in the angle of inclination of the device. The upwardly flowing steam or gases pass through the louvered panels, described more fully hereinafter, and the sprays from the nozzles 12, which are preferably fine steel nozzles in a plastic spray pipe 11, are directed upwardly toward the baffles or vanes of the louvered panels.
As best seen in FIGS. 1 and 2, each louvered panel comprises a plurality of lower shutter blades, vanes, or baffles 2, and a set of upper blades, vanes, or baffles 3. The shutter blades or baffles are supported in slots in a vertically oriented elongated baffle support plate 1 which is positioned on beam 10 by means of spacer elements 5, and the plate 1 with the shutter blades or baffles mounted therein is retained in position by bolts 7 connecting transverse ledges 8 to beam 10, and more particularly to spacers 18 extending transversely of beam 10. The transversely extending ledges 8 hold in position longitudinally extending ledges 6 which engage the upper set of blades or baffles 3.
Baffles 2 and 3 have noses, ribs, or flanges 4 and 4a, respectively, and these flanges or ribs extend in respective opposite directions in order to provide impinging areas for aiding in the removal of solid pollutants from the steam or gases flowing upwardly through the device.
The steam or gases, carrying the solid pollutants, pass between adjacent lower baffles 2 and upper baffles 3, so that the stream of the steam or gases is deflected to flow in a turbulent manner and impinges upon the baffles, particularly at the location of the noses or flanges 4 and 4a. Consequently, and due to the turbulent flow and such impingement, the solid pollutants are separated from the upwardly flowing stream of steam or gases and collect largely at the locations of the flanges or noses 4 and 4a.
The pollutants thus trapped on the baffles during a coke quenching operation taking place in a coke quenching tower below the stack or tower containing the baffle device of the present invention, are flushed from the baffles 2 and 3 in between successive coke quenching operations. This flushing is effected by connecting the discharge pipe 11 to a source of liquid, such as water, under pressure for discharge of the fluid through the nozzles 12 which are directed against the baffles 2 and 3. Following such quenching, the baffles 2 and 3 which have been cleaned of pollutants by the flushing operation, are now ready to trap pollutants evolved in a subsequent coke quenching operation.
The device shown in FIGS. 1, 2 and 3, which is adjustably positioned in the casing 16, is preferably reinforced by a diagonal brace 17 extending from one support member 14 upwardly to a central connection on the supporting means or support beam 13. When it is desired to change the inclination of the device, it is necessary only to either elongate the device or to shorten the device by, in the one case adding and in the other case removing, panels or panel sections such as shown at 9', 9" and 9'". Each panel section includes not only the baffles 2 and 3 but also an associated spray conduit and nozzle section associated with each panel section. The spray conduit and nozzle sections are releasably coupled to each other, and flexible connections may be provided where necessary.
In the arrangement shown in FIG. 3, the upper end 26 of the support beam 13 preferably is anchored on the right hand support structure 14, as by a pivot or the like 26a, and the length change is effected by adding or removing the lower panel section 9 to facilitate pivoting the whole structure to any one of the dotted-line positions indicated at 13', 13" or 13'" for example. The change in length is similarly effected when the support beams 13 are pivoted at 24a to the left hand support structure 14, the inclination in this case being reversed from that shown in FIG. 3.
FIGS. 4 through 16 illustrate a further embodiment of the invention corresponding, in principle, to the embodiment shown in FIGS. 1, 2 and 3. More particularly, FIGS. 14, 15 and 16 show, in greater detail, the baffle structure shown in FIGS. 1, 2 and 3, which baffle structure is the same as that shown in FIGS. 4 through 13.
Referring to FIG. 4, a discharge stack 101 is arranged to receive the stream of steam and gases, including pollutants, flowing upwardly from a coke quenching tower located below the stack 101 and not shown, stack 101 having a discharge mouth 101a at its upper end. The device for trapping the pollutants from the fumes arising from a coke quenching operation is mounted in stack 101 below discharge mouth 101a. The illustrated device comprises supporting beams 103 and 104, of which supporting beam 104, is pivoted, by means of a pivot 102, to a vertical support 102a secured to the inner surface of the wall of stack 101. Supporting beam 103 carries, at its outer end, a roller 120 mounted on a shaft 126 supported on brackets 123 secured to beam 103 by bolts 133, as more particularly shown in FIGS. 5 and 6.
Roller 120 is adapted to run up and down in a guideway 125a formed, as best seen in FIG. 6, by a rectangular beam 125b and lateral strips 125d secured to beam 125b by bolts 125c. Guideway 125a is fixed to that wall of stack 101 opposite the wall to which the support 102a is fixed. Of course, multiple supports 102a and multiple guideways 125a may be provided depending on the width of the device and, consequently, the number of supporting beams 103 and 104. However, for the sake of simplicity in the description, the description will refer only to single elements 102a and 125a.
Lifting and lowering of supporting beam 103, with pivoting of support beam 104 about pivot 102, is effected by a traction rope 117 attached to a supporting bar 121 by means of a clamp 117a. In turn, and as best seen in FIG. 5, supporting bar 121 is secured to each supporting beam 103 by bolts 122. Traction rope 117 is trained over pulleys 118 and secured to a manually actuable hoist means, such as a winch 119 which is mounted in a suitable bracket out on the exterior of stack 101. As should be clear from FIG. 4, while support 102a is mounted on the right side of stack 101 and guideway 125a is mounted on the left side, the positions of these elements may be reversed with winch 119 being mounted in the support shown in the right hand side of the stack.
Supporting beams, or beam sections, 103 and 104 may be telescoped to change the overall width of the device in accordance with its angle of inclination. For this purpose, and as best seen in FIGS. 5 through 16, supporting beams 103 and 104 are interconnected, for relative longitudinal displacement, by rolles 105 mounted on a shaft 131 supported by means of fork strips 107 and rollers 106 mounted on a shaft 124 supported by means of fork strips 108. Rollers 105 engage supporting beam 103, and the fork strips 107 embrace supporting beam 103 and are connected to supporting beam 104 by bolts 128. Rollers 106 engage supporting beam 103 and fork strips 108 are connected to supporting beam 104 by means of bolts 134. Rollers 105 and 106 are so disposed that beams 103 and 104 can be shifted parallel too each other and without sagging under their own weight. To prevent relative lateral displacement of supporting beams 103 and 104, guide pieces 129 are secured to supporting beam 104 by bolts 132 and extend on opposite sides of supporting beam 103.
Panel sections 116 for accommodating the baffle structures for trapping pollutants during quenching of coke rest on supporting beams 103, 104. These panel sections are shown in FIGS. 11 and 12 in longitudinal sectional views which are taken perpendicularly to each other and to a larger scale than that used in FIG. 4. Each panel section comprises supporting bars 139 and cross bars 127 connected to each other by means of threaded bolts 130. As the coke quenching fumes pass upwardly through stack 101, they exert a pressure on the panel sections containing the baffles. In order to prevent lifting of the panel sections from supporting beams 103 and 104, the panel sections are retained by means of clamping strips 135 secured to supporting bars 139 and cross bars 127 by means of bolts 141. Spacers 136 are provided to assure that the function of the baffles is not affected unfavorably by the clamping strips 135.
Spacers 140 are supported in supporting bars 139 by bolts 141, and baffle supporting plates 100 engage spacers 140. Baffle supporting plates 100 are formed with slots 142 and 143, at respective opposite edges thereof, and baffle blades 137 and 138, made of polypropylene are received in these slots. These baffles, at their free edges, are formed with flanges or rib portions 137a and 138a projecting from the baffle at substantially a right angle. The baffle blades serve to entrap the coke dust and other solid pollutants carried upwardly by the fumes from the coke quenching operation.
Crossbars 127 rest on the supporting beams 103 and 104, and are of dimensions providing suitable clearance for the rollers 105 and 106. The crossbars 127 may be secured to supporting members 103 and 104 by suitable bolts 150 as best seen in FIG. 15.
During a coke quenching operation, the solid pollutants rising upwardly with the fumes from the coke quenching operation are trapped by the baffles 137 and 138 in the same manner as described in connection with the baffles 2 and 3 of the embodiment shown in FIGS. 1, 2 and 3. Between successive coke quenching operations, baffle blades 137 and 138 are flushed in order to remove the deposited solid pollutants, such a coke dust, from the blades 137 and 138. For this purpose, and as shown more particularly in FIGS. 4, 13, 15 and 16, respective spray pipes 109 and 110 are supported on beams 103 and 104, and are formed with spray openings 125, or provided with nozzles 125, directed toward baffle blades 137 an 138. The spray pipes are secured to the respective beams 103 and 104 by means of respective holders 109a, 109b and 110a, 110b. Flushing water is supplied to spray pipe 109 through a feed pipe 113 connected, in turn, to a flexible connecting tube 112 and a water system connection 114. Flexible connecting tube 112 permits an easy pivoting of the water spray system following the inclination of supporting beams 103 and 104. Water is supplied to spray pipes 109 and 110 through tees 115 connected thereto and to feed pipe 113 or flexible pipe 11.
FIG. 13 illustrates how flexible pipe 111 follows the telescoping of the supporting structure as the angle of inclination of the structure is changed by lowering or raising supporting beam 103 telescoped to supporting beam 104.
It should be noted that the details of the mounting of the baffles, and the associated panels, as shown in FIGS. 11, 12, 14, 15 and 16 are correspondingly used for the mounting of the baffles shown in FIGS. 1, 2 and 3.
At the risk of repetition, it should again be emphasized that, during a coke quenching operation, no water is supplied to the spray pipes, and the baffles trap solid pollutants, such as coke dust, rising, with the fumes from the coke quenching operation, to the stack 101 which is disposed above in communication with a coke quenching tower. It is only inbetween successive coke quenching operations that water is supplied to the spray pipes solely to flush the solid pollutants from the baffles, and not for the purpose of quenching coke.
While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from these principles.
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The device is positioned in a stack arranged above a location where coke quenching is performed. The coke quenching, which takes place below the stack, evolves steam and gases containing solid coke particles or dust, and which must be prevented from passing into the outside atmosphere. The steam and gases flow upwardly through the stack and the device separates the solid coke particles and dust from the steam and gases. The device comprises a support beam carrying a plurality of shutter-like baffles, of plastic material, and liquid spray elements, and which is variable in length and positioned either obliquely or horizontally across the upper portion of the stack. In between successive coke quenching operations, the liquid spray elements are activated to flush the trapped solid coke particles and dust from the shutter-like baffles. The adjustable length of the device provides for the device to be positioned to extend across the stack at varying angles, or even horizontally. The device may be pivoted at either end of the stack so that it may be swung about the pivot to vary the angle of inclination of the device in the stack, and the adjustable length of the device accommodates the various oblique positions or the horizontal position. The support beam advantageously is supported by a diagonal brace extending from one wall of the stack to the support beam.
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RELATED APPLICATIONS
This application claims priority benefit of and is a continuation in part of U.S. patent application Ser. No. 12/829,086 filed on Jul. 1, 2010 incorporated herein by reference. This application also claims priority to U.S. provisional application Ser. No. 61/246,347, filed Sep. 28, 2009 also incorporated herein by reference.
BACKGROUND OF THE DISCLOSURE
a) Field of the Disclosure
Disclosed herein is the description of an improved rollover oil valve assembly and method for retrofitting vehicles with said rollover oil valve assembly. For examples, the vehicle may be a snowmobile, a four-wheel ATV or a similar off-road vehicle.
SUMMARY OF THE DISCLOSURE
Tethered dead man switches, such as disclosed in U.S. Pat. No. 3,938,613 (incorporated herein by reference), are well known in the art of off-road vehicles. These switches generally utilize a tether, coupled between a vehicle operator and a vehicle ignition system. When the vehicle operator is removed from the vehicle, the tether switch is opened and the ignition system of the vehicle is shut off. This has shown to be a significant safety measure, as the vehicle would otherwise continue to run, potentially damaging itself, or injuring the operator, or others. As is well known in the art, it can be very dangerous to the user, or damaging to the vehicle, if the vehicle is allowed to continue forward without an operator controlling the speed and direction of the vehicle. This is especially problematic in many types of watercraft, three or four wheel ATV's, and snowmobiles, which can very easily continue forward in a straight line on their own for a long period of time.
Disclosed herein is a device which provides an additional safety measure by utilizing in one form the dead man (tether) or kill switch, switch previously described, in combination with a valve and actuator, to keep oil from leaking out of the lubrication system of the vehicle in a rollover situation. Many prior art dead man switches, tethered or otherwise, operated by opening the switch, and “shutting off” power to the ignition system of the vehicle, but had no provision for containing fluids within the engine, fuel, or lubrication systems.
An additional problem is often caused in off-road vehicular accidents due to the arrangement of the engine oil tank relative to the engine air intake or other oil lines leading to or from the engine oil tank. Often, the engine oil tank is vented or otherwise fluidly coupled in such a way that when the vehicle is in an overturned orientation, the engine oil within the engine oil tank drains out of the engine oil tank. The oil is not recoverable when the vehicle is returned to an upright position.
Disclosed herein is a method and apparatus for utilizing a dead man switch in combination with a valve, arranged such that when the tether switch is activated, an signal is sent to the valve to close said valve. In one form, the signal closes the valve so that oil is prohibited from running past the valve and being lost to the environment, causing damage to environment, and potentially damaging the engine when the engine is re-started.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of the fluid connections between an engine oil tank and a vent, such as an engine air intake, in one form.
FIG. 2 is a drawing of an installed oil line solenoid valve, in one form.
FIG. 3 is a schematic diagram of the electric connections in an oil line solenoid valve shutoff system, in one form.
FIG. 4 is a drawing of a tether attached to a vehicle, in one form.
FIG. 5 is a drawing of a retrofit kit for an oil line solenoid valve shutoff system, in one form.
FIG. 6 is a schematic diagram of the electric connections in an oil line solenoid valve shutoff system, in one form.
FIG. 7 is a schematic diagram of the electric connections in an oil line solenoid valve shutoff system utilizing a control module, in one form.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a schematic diagram of an oil shutoff system 20 in one form, comprising an electric solenoid control valve 22 , which is fluidly coupled to a connecting hose 24 running to an engine oil tank 26 . While other valve types could be utilized, including pneumatic, spring, hydraulic, non-solenoid electric, or others, the primary disclosed embodiment will describe an electric solenoid control actuator in mechanical communication with the valve 22 . A supply line 80 and return line 82 are fluidly connected between the oil tank 26 and the engine 84 . The electric solenoid control valve 22 may be coupled to a connecting hose 28 , fluidly coupled between the valve 22 and a vent 30 , engine block, or, in one embodiment, an engine air intake 30 . In one form, it is often found that venting the engine oil tank 26 through the engine air intake provides significant advantages including that the air intake filters air to the engine oil, and also allows blow-by gasses to vent to atmosphere without building up pressure in the oil tank 26 .
Two different lubrication systems are common in internal combustion engines; dry sump and wet sump. Four stroke engines commonly used in snowmobiles, ATVs, motorcycles, race engines, aircraft, etc. often use dry sump oiling systems which have several advantages over wet sump systems. In a dry sump system, the oil supply is stored in a tank, thus oil capacity is increased relative to wet sump systems. A shallow oil pan can be used in such dry sump systems to allow the engine to sit very low in the chassis, and, because the oil supply is at the bottom of the tank, oil supply is improved in rough terrain use. Dry sump systems use two or more oil pumps. A supply pump provides pressurized oil to lubricate internal engine parts and a scavenge or return pump is utilized to remove the oil from the bottom of the engine and send it back to the tank. The two pumps can be incorporated into one pump unit having separate input ports and output ports for the supply and return oil lines. Such a pump unit would typically have two portions, these being a supply portion and a return portion. Because the rate of oil return can be different than the rate of supply, the oil tank is normally vented to as previously discussed, to prevent tank pressure buildup (or vacuum). Tank pressure buildup can cause poor oil scavenging performance and could lead to oil system failure. Some factors that can change the supply to scavenge rate are rapid RPM changes and compression gases leaking past the piston rings, often referred to as blow by gases. These blow by gases increase crankcase pressure, which can increase the scavenge pump flow rate. The change in flow rate can in some instances raise or lower the oil level in the tank, which can create undesirable tank pressure if not vented correctly.
Looking to FIG. 2 , one embodiment of the electric solenoid control valve 22 is shown coupled to the connecting hose 28 and further coupled to the engine air intake or other assembly. As shown in this embodiment, a plurality of hose clamps 32 can be utilized on the input side and outlet side of the solenoid valve 22 to ensure a pressure-retaining seal between the connecting hoses 24 / 28 and the solenoid 22 . The input side 34 of the oil line solenoid 22 in this example is coupled to the connecting hose 24 , which delivers tank vapors to the oil line solenoid 22 from the engine oil tank 26 in normal operating conditions. As previously mentioned, the tether switch is activated when the tether (normally attached to the user/driver) is removed from the vehicle, such that the tether switch is actuated and power is cut from the engine, shutting off the engine. Concurrently, in one form, power is supplied to a normally open oil line solenoid 22 , shutting the valve. While it may be alternately possible or desired to incorporate a normally closed oil line solenoid valve 22 , having a normally closed valve may result in less than satisfactory operation in some instances. In one example, in the event of loss of power supplied to the valve, such as by a dead battery, the valve would close, potentially causing damage to the engine. As these vehicles are often operated very far from assistance, such damage to the engine could be catastrophic to the rider. By utilizing a normally open valve, this potential for damage is eliminated as the valve will remain open when power is lost to the valve.
FIG. 4 shows one embodiment of the oil shut off system 20 being utilized on a snowmobile 36 , although, as previously discussed, the system 20 could equally be utilized on other vehicles. As shown, the cowling of the snowmobile has been removed so that the front part of the engine compartment can be easily seen. The tether 38 is shown having a first end 40 coupled to the tether control switch 42 . The tether 38 is shown in a common stowed position wherein it is wrapped around the gas cap 44 and back to the tether coupling 46 . In normal operation, the tether coupling 46 would be attached to the driver, such that when the driver is not in a position to properly control the vehicle, such as being removed therefrom, the tether switch 42 is activated shutting off the vehicle. As previously discussed, in one example: when the tether switch 42 is activated the solenoid control valve 22 will close thus keeping oil from leaking out through the oil line vent 30 . When the vehicle is returned to an upright position, the tether 38 may be reattached to the tether switch 42 , opening the valve 22 , allowing tank vapors to circulate through the system, such that the vehicle 36 can be restarted.
The schematic diagram shown in FIG. 3 shows one embodiment for interconnecting the individual components to achieve the desired outcome. In one form, the tether switch 42 is wired in series with the factory mounted handlebar kill switch. The tether switch 42 is shown coupled to the “hot side” 48 of a kill switch wire which may lead to the ignition switch of the vehicle. In one form, a double pole single throw switch is utilized for the tether switch 42 . The output side of the tether switch 42 in one form is coupled to leads 52 and 54 . The lead 52 couples to the power input source (cold side) of the vehicle kill switch (in one form the vehicle handlebar OEM kill switch), and the lead 54 is coupled to the input side of the electric solenoid valve 22 , in one form, through a fuse 56 . In one form, a three-amp, in-line fuse can be utilized. In one form, the output lead 58 from the solenoid control valve 22 connects to the ground at a grounding plug 60 . The lead 58 , or grounding wire, is also shown in FIG. 2 . In one form, it may be desired to have an audio or visual signal to indicate the status of the solenoid control valve 22 . In one form, as shown in FIGS. 3 and 5 , a light or light emitting diode (LED) 62 can be included and connected by way of leads 64 and 66 to illuminate when power is supplied to the solenoid control valve 22 and indicate that the valve is in the closed position.
In another embodiment, shown in FIG. 6 , a control relay 86 is used instead of the double pole tether switch 42 previously described. In this embodiment, the coil of the control relay 86 is electrically coupled between the fuel pump/ignition/ECU (engine control unit) wire 90 and ground 92 by way of a lead wire. Thus, when power is supplied to the fuel pump, the relay coil 88 is energized, and the normally open terminal 95 is closed to the common terminal 94 . To engage the disclosed rollover valve, the user engages the kill switch while leaving the key in the on position; this stops the engine and power is cut from the fuel pump/ignition/ECU, the relay coil 88 is not energized, and the normally closed terminal 98 is closed to the common terminal 94 . Alternatively to connecting to the fuel pump power supply/ignition/ECU, the relay coil 88 could alternatively be coupled to a standard handlebar kill switch. As the normally closed terminal 98 is coupled to the normally open solenoid valve 22 , power to the normally closed terminal 98 would close the solenoid 22 , which is fluidically coupled as described above. A fuse 56 may be interposed between the power supply line 102 and the common terminal 94 . In one form, the power supply line 102 is coupled to the ignition switch such as to have power supplied only when the ignition key is on.
In another form, the leads 102 and 90 are connected to the terminals of a normally closed type tether switch. During engine operation the tether switch contacts are closed, allowing the engine to run and supplying power to the relay coil 88 . This energizes the relay coil 88 , and closes the circuit between the common terminals 94 and 95 . Thus power is not supplied to the terminal 98 , nor to the solenoid valve 22 . This allows the valve to remain open and vent the oil tank.
When the tether is pulled, the contacts on the tether switch open, stopping the engine and cutting power to the relay coil 88 . This allows the contacts to close between terminals 94 and 98 , which in turn supplies power to the solenoid valve 22 , closing the solenoid valve 22 . This allows for operation of the solenoid valve 22 even when the ignition key is in the on position during the rollover event.
In one form, as shown in FIG. 6 , an indicator 62 , as previously described, can be utilized to indicate to a driver that the solenoid valve 22 is closed, and that the vehicle should not be started.
Looking to FIG. 5 a retrofit kit 68 , is shown in one form. The kit is utilized for converting a vehicle, such as a snowmobile, to utilize the disclosed solenoid valve. The kit 68 in one form comprises a wiring harness 70 . The wiring harness 70 connects the solenoid control valve 22 to the tether switch 42 and also comprises leads 48 and 52 , which may be coupled to an existing kill switch. The wiring harness 70 also comprises the leads 64 and 66 , which may be coupled to the LED indicator 62 if utilized. The ground wire 60 is also shown, as well as a grounding terminal 61 , which would couple the grounding wire 60 to the vehicle such as at the frame. The in-line fuse 56 is also provided as a portion of the wiring harness 70 . A tether 38 and a tether coupling 46 are also shown. In normal operation, the tether coupling 46 is attached to the user so as to pull upon the tether 38 when the user is removed from the vehicle. The jumper wire 78 can be utilized as an emergency device in case of losing the tether, or in failure of the tether switch 42 . If the tether switch 42 fails, the tether switch can be “jumped” with the jumper wire 78 to re-open the solenoid valve 22 . To utilize the jumper wire 78 in case of failure of the tether switch, the tether switch may first be disconnected from the wiring harness and then wire 48 could be jumped to wire 52 , bypassing the tether switch. The jumper wire 78 could also be used in a similar manner in the event of failure of the kill switch. A plurality of zip ties 72 or similar attachment devices may also be included, as well as a plurality of hose clamps 32 , to couple the fluid input 74 and fluid output 76 of the solenoid control valve 22 , as previously discussed.
A wireless tether could also be utilized. Such wireless tethers are becoming better known, and they generally activate the tether switch when the user wearing the transmitting portion becomes removed from the vehicle. A manual reset is often utilized in such a system, such that the ignition and oil line valve will not automatically become active when the user returns to the vehicle. This is important, as the vehicle may not be in an upright position or may be otherwise unusable.
An improvement is disclosed further comprising an electronic control module (ECM) circuit or rollover valve control module (ROVCM) 104 shown in FIG. 7 . The ECM/ROVCM has inputs A-B-C which may be electrically connected to the system as shown, or when desired the module may be detached and a jumper wire 78 may be utilized across the wires attaching to terminals A-C to “bypass” the module during a fault situation. In one form, the module 104 comprises a programmable output voltage, input voltage monitoring and internal timer settings. It has been found that in many applications, the solenoid valve 22 does not require the same voltage to maintain the valve in a certain position, as it requires to open or close the valve. Thus, the module 104 may provide output voltage to the solenoid valve 22 in one example as a pulse width modulated output signal to the optional LED 62 and to the electric solenoid valve. When the tether switch 42 opens for example due to removal of the tether 38 , the control relay 86 closes relative to terminal 98 . Power is then provided to the module 104 which energizes terminal C and activates the optional LED 62 and causes the shut-off solenoid valve 22 to close. Power from the module may be provided as a pulse width voltage, which also in some examples allows for a higher voltage output than input to the module as a non-pulsed voltage. After the valve is closed, for example after a short time interval which may be programmed into the module 104 , power may be provided from the module 104 to the solenoid valve 22 and to the optional LED 62 as a different wave form, or lower voltage to reduce draw on the battery until the system is reset.
In one example, when the engine is running, the tether switch 42 contacts are closed between the hot side 48 and the lead 96 . This allows ignition voltage to be applied to relay terminal 108 . This closes the relay contacts between terminal 94 and 95 . Voltage is then allowed to supply power to the ignition system, engine control module, handlebar kill switch or fuel pump relay in one form via wire 106 . This in turn allows the engine to operate.
As briefly mentioned above, the ECM/ROVCM in one example is programmable so that output voltage can vary depending on if the shut-off valve is closing remaining in a closed state. This allows for a higher voltage to rapidly close the valve and a lower voltage to save on battery power once the valve is closed. The ECM/ROVCM in one example also has a battery voltage monitoring feature. This battery monitoring feature allows the shut-off valve to remain closed for a specific amount of time and automatically shut down the system if the vehicle's batter voltage drops to a pre-programmed setting.
In one example, the module 104 monitors the input voltage in such a way that when a lower limit threshold voltage is reached, say for example below 10V in a 12V system or below 5V in a 6 volt system, the module 104 will shut off. The battery type also effect this, for example testing has shown an effective lower threshold for a lead acid battery may be 12.1V and a lower threshold for a Lithium Ion battery may be 13.2V. This battery monitoring prevents the system from drawing down power below the threshold at which the battery does not have enough power (as determined for example by the battery voltage) to re-start the engine of the vehicle. It is conceived that a user may leave a vehicle unattended with the ignition on, and the tether removed. While this situation will stop the engine from running, the user may be unaware that power (current) is being drawn from the system to maintain the valve 22 in the closed position. If an LED or other indicator is used, the indicator may also be reducing the power available in the battery.
If it is desirable not to have an ECM/ROVCM in the system, the ECM/ROVCM may be replaced by a simple jumper wire connection 78 , that connects terminals “A” and “C” of the module 104 .
By providing power to the fuel pump/ignition/ECU via lead 106 , the engine is generally prohibited from operating while the solenoid valve 22 is closed which could cause catastrophic damage to the engine.
While the present invention is illustrated by description of several embodiments and while the illustrative embodiments are described in detail, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications within the scope of the appended claims will readily appear to those sufficed in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of applicants' general concept.
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Disclosed herein is a device which provides a safety measure to vehicles by utilizing the dead man (tether) switch, or other electrical connection, in combination with a valve and actuator, to keep oil from leaking out of the lubrication system of the vehicle in a rollover situation.
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